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AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.01.B2143: Model Exploration and Optimization Using Distributed and High Performance Computing

Harris, J.

(937) 938-3937

Computational complexity grows quickly with increases in the granularity of models, the fidelity of the models' operating environment, and the time scales across which these models are used in simulations. We must find ways to deal with the computational demands of large-scale basic and applied cognitive modeling. One approach is to acquire more computational horsepower, such as through high performance computing (HPC) clusters, volunteer computing, or cloud computing. Another approach is to reduce the size of the required computational space through predictive analytics and parallelized exploration and optimization algorithms. Our view is that it is only through the combined use of these approaches that we can meet our far-term scientific and technological objectives, both as a research team and as a broader research community.

Keywords: high performance computing (HPC), intelligent search algorithms (ISAs), computational mathematics

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.07.B0077: Perceptual & Cognitive Factors in Real-Life Information Seeking: Theories, Models, & Methods

Warren, R.

(937) 255-3165

People actively seek information. They may want the information just out of curiosity and for entertainment (e.g., watching TV), or to immediately act on it (e.g., checking traffic to change lanes), or for long term planning and decision making (e.g., gathering data on used cars) The search may be basically sensorial (sniffing an aroma, visually scanning a crime scene, listening for a sound in the night), or social (asking for directions), or by reading books and on-line internet pages, or by using sophisticated technology. Searches may be efficient or inefficient, successful or unsuccessful, or truly informative or riddled with errors and wrong conclusions. Search errors can be due to misperception or misinterpretation (false alarms) or misses (failure to find what is there). Many factors can influence the search itself and its success or failure such as attention, prior knowledge, training, biases, cultural factors, social factors (individual versus team search), time, resources, and technology. Two people may view the same event but attend to different information, or may react differently to the same information. Since curiosity and search behavior is so central to humans, we need to better understand basic perceptual, cognitive, and affective factors in information seeking. By understanding, we do not mean a collection of anecdotes and rules of thumb. Rather we seek an ecologically-relevant general theory based on real-world empirical facts and expressed in mathematical and computational models. We need metrics for quantifying available information and for assessing search performance. Ultimately, we seek methods to augment humans searching for information and to increase performance in real-life ecologically-valid situations.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.07.B0078: Auditory Perception and Speech Communication

Iyer, N.

(937) 255-4274

We conduct basic and applied research on auditory perception and speech communication. Auditory perception research focuses on the perception of real and synthetic auditory localization cues in simple and complex environments, as well as the interactions of the auditory and visual sensory systems. We also have a strong basic research program examining the limits of human multitalker speech perception. World class facilities for human auditory research include a large anechoic chamber that has a 14-foot diameter geodesic sphere with 277 loudspeakers, 3 large reverberation chambers with high intensity sound systems producing levels of up to 137 dB, state-of-the-art computer facilities, and a panel of 10 part-time listeners for conducting psychoacoustic experiments. A capable hardware, software, and technical support staff is available to assist visiting faculty members in modifying and using the facilities for their research.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.07.B5700: Increasing Information Transfer in Audio Display Systems

Simpson, B.

(937) 255-4463

Human audition is an amazingly complex modality capable of extracting spatial, spectral, and temporal information from multiple simultaneous sound sources even in adverse listening environments. However, most real-world audio display systems rely on relatively simple stimuli that fail to take full advantage of the inherent capabilities of human listeners. The goal of this research is to find ways to increase the amount of information transferred to listeners through audio display systems. The effort involves two broad areas of research. The first area focuses on the generation of robust and intuitive azimuth, elevation, and distance cues that maximize the transfer of spatial information in audio displays, especially in noisy environments that involve more than one virtual sound source. The second area focuses on improving the segregation of competing sound sources in complex listening environments, especially those that involve more than one simultaneous speech signal. A major component of this research is a study of the role that non-energetic "informational" masking plays in the perception of multiple speech signals.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.07.B5702: Spoken Language Translation and Retrieval

Slyh, R.

(937) 255-9248

The objective of this research is to improve the performance and robustness of algorithms for speech-to-speech translation and cross-lingual information retrieval from speech, video, and multimedia signals. Of particular interest are algorithms and techniques to facilitate rapid development and porting of systems to new languages and domains. Research areas of interest include the development and application of new speech processing features, including biologically-based and/or perceptually-based features (e.g., auditory models and speech production models); novel classifiers; robust methods for translation; robust methods for information retrieval; and methods for system fusion.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.08.B7532: Mathematical Modeling for Performance Prediction: Mechanism Development to Account for Effects of Cognitive Moderation

Jastrzembski, T.

(937) 938-4046

Researchers at the Air Force Research Laboratory’s Human Effectiveness Directorate have developed, matured, and made more robust a mathematical model for performance prediction, known as the Predictive Performance Equation (PPE) (see Jastrzembski, Gluck, & Gunzelmann, 2006; Jastrzembski, Gluck, & Rodgers, 2009). This model has been carefully validated across a variety of domains and contexts – scaling from laboratory experimental data available in the psychological literature to increasingly complex and militarily relevant team and pilot data measured in the Air Force Research Laboratory‘s Distributed Missions Operations testbed (Schreiber, Stock, & Bennett, 2006). The predictive model functions by capturing learning signatures and mathematical regularities from the human memory system through calibration of learning and decay parameters using historical performance data, and extrapolates those unique learning signatures to make predictions of performance at specific later dates in time. The model critically extends that previous research by additionally accounting for the effects of temporal distribution of training on learning – a well-documented phenomenon known as the spacing effect – which reveals that given two training regimens of equal length and equal amounts of training opportunities, learning is more stable when practice events are spaced further apart in time. This research seeks to extend the model even further, by incorporating mechanisms that explicitly attenuate performance through effects of cognitive moderation (i.e., enhancement of performance from brain stimulation or caffeine; decrement of performance from fatigue or excess workload), so that a more complete picture may be gleaned regarding the range of likely performance effectiveness under known conditions.

Anderson, J. R., & Schunn, C. D. (2000). Implications of the ACT-R learning theory: No magic bullets. In R. Glaser (Ed.), Advances in instructional psychology: Educational design and cognitive science, Vol. 5. Mahwah, NJ: Erlbaum.

Jastrzembski, T. S., Gluck, K. A., & Gunzelmann, G. (2006). Knowledge tracing and prediction of future trainee performance. I/ITSEC annual meetings, Orlando.

Jastrzembski, T. S., Gluck, K. A., & Rodgers, S. (2009). Improving military readiness: A state-of-the-art cognitive tool to predict performance optimize training effectiveness. I/ITSEC annual meetings, Orlando.

Schreiber, B. T., Stock, W. A., & Bennett, W. (2006). Distributed mission operations within-simulator training effectiveness baseline study: Metric development and objectively quantifying the degree of learning. AFRL-HE-AZ-TR-2006-0015-Vol II. Available online at: www.dtic.mil.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.08.B7533: Mathematical Modeling of Human Performance Efficiency in Complex Decision Environments

Blaha, L.

(937) 255-0425

We are interested in assessing the perceptual and cognitive efficiency in complex environments. In particular, given disparate sources of information or data, what information is extracted and how is that information represented and combined in order to perform a specific task? The sources of information may include multi-spectral imagery or other sensor data feeds, representations of unstructured data, or multi-sensory inputs from the task environment. The goal of this research is to combine empirical techniques in psychophysics and mathematical modeling of response time and accuracy data to define the key information processing characteristics supporting decisions based on multiple sources of information. This may entail extending current information processing models (e.g. ideal observer, efficiency ratios, general recognition theory, random walk models of response time) or developing new mathematical models to better assess performance efficiency measured by response time and accuracy simultaneously. A larger goal is to then utilize these models capturing and characterizing human performance in order to improve the means of information presentation to optimize decision making efficiency.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.08.B7534: Visual Analytics

Havig, P.

(937) 255-3951

The field of information visualization is wide ranging and runs the gamut from aesthetically pleasing visualizations to those that give much needed information to a user on demand. Air Force applications for cyberspace need to rely heavily on information visualization techniques to provide this “on demand” capability in such a way that users do not need to be experts in the field to understand a visual display. Further, visual analytics looks at how to optimize the interaction with the visualization so the user spends more time exploring and understanding the visualization and less time trying to figure out how to navigate the environment. We are interested in this cross road between optimal user interface and visualization of large, complex data sets.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.08.B7535: Human Automation Research

Draper, M.

(937) 713-7015

The Air Force Research Laboratory’s Supervisory Control and Cognition group explores the scientific underpinnings of human-automation interaction and teaming. This knowledge is then utilized to design, develop, and evaluate enabling human-automation interface architectures, novel control methods & intuitive information displays. The goal of this research is to achieve flexible, fault-tolerant single-operator supervision of multiple semi-autonomous systems. Especially challenging research areas include dynamically adjustable autonomy (initiated by human and by machine), cognitively compatible feedback on automation status/intent, intuitive supervisory control methodologies, information visualization and management (e.g., information fusion/filtering, information glyphs, multi-sensory displays), and decision aiding tools (e.g., attention cueing, decision support methods, intelligent associates, etc.). Additionally, we are interested in the development and validation of metrics and frameworks associated with supervisory control applications.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.08.B7536: Cyber Effects Research

Vidulich, M.

937-938-3571

As the joint forces of the military become more and more dependent on cyberspace to plan and carry out missions, it has become increasingly important to understand the impacts of and develop mitigation strategies for decision making under a cyber attack (fight through). The objective of this in-house research program is to enable the modeling of psychological effects of cyber attacks on human operators. Currently, there are 3 important areas that need to be addressed to meet these needs. First, appropriate experimental tasks must be identified or created and validated. Second, the cognitive and psychophysiological effects of cyber attacks must be described and quantified. Third, mediations, including, but not limited to, adaptive automated aids, cognitive augmentation, or real-time team rebalancing, for those negative effects must be proposed and validated.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.09.B0919: Human Characterization and Activity Recognition in Full Motion Video (FMV) from Fielded Systems

Lochtefeld, D.

(937) 255-2570

Modern defense applications have become increasingly human-centric, focusing, for example, on identification of individual or group characteristics and behavior. The purpose of this research project is to explore human characterization and activity recognition from full motion video using realistic resolutions and observation geometry from fielded systems. Research goals include identification and development of techniques to characterize humans observed in FMV using qualitative and quantitative features in order to determine the likelihood that that particular person was observed in another, seemingly unrelated, video stream. Extraction of anthropometric, biomechanics, and soft biometric methods are desired as well as pattern recognition and machine intelligence techniques to determine match confidences.

Candidates with demonstrated knowledge and experience in machine intelligence, pattern recognition, and computer vision are desired. Selected applicants will be expected to work with USAF staff, collaborating university faculty, and contract support staff to develop the methodologies and conduct experiments to validate them if necessary.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.09.B1111: Real-time Enhanced Visual Targeting

Pinkus, A.

(937) 255-8767

With the advent of miniaturized digital sensors, portable multispectral imaging systems are being developed that incorporate computational manipulations of the imagery. These new systems include computer algorithms that register, enhance, and/or fuse multi-sensor derived imagery. Sensor fused day/night systems can offer superior imaging performance by providing additional system capabilities such as super-resolution, camouflage breaking, smoke penetration, de-noising, jitter reduction, adaptive contrast improvement, motion detection, and bio-inspired automatic salient-feature cuing for targets embedded in clutter. To design a human visual performance optimized agile imaging software architecture, the Real-time Enhanced Visual Targeting Project is pursuing multiple research goals: (1) develop human in the loop test methodologies to objectively evaluate the efficacy of various enhancement and fusion algorithms, allowing down-selection to an optimized set of algorithms, (2) perform critical psychophysical and eye-tracking studies to understand human visual search behavior with naturalistic stimuli, and (3) design software architectures that adaptively control image quality to continuously maintain the most tactically informative picture, in real time.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.09.B1133: Trust Calibration Science

Lyons, J.

(937) 255-8734

This research will investigate the psychological (e.g., heuristics/biases), technological (e.g., transparency design features), or contextual predictors of trust calibration between humans and machines. Special emphasis is placed on empirical evaluation of how one or more facet described above shapes the trust and subsequent performance of human-machine systems. We would like to understand how to predict when an individual will engage in misuse or disuse when aided by intelligent automation and how to augment the human-machine system to reconcile the misalignment to promote better human machine system performance.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.11.B0086: Predictive Toxicology

Schlager, J.

(937) 904-9570

Mathematical modeling provides quantitative prediction of the dose- and time course- responses of mammalian systems to toxic chemicals. Simple and complex in vitro toxicological models can provide novel findings uncovering chemical-response mechanisms. This research program focuses on developing methods and computational models in application across in vitro/single cell to complex whole animal/human systems for more rapid assessment and analysis of chemical and material toxicity. Research areas support the overall advancement of human toxicokinetic and toxicodynamic modeling of exposure to single and mixtures of operational chemicals and materials. Approach sought will aid in development of biologically-based kinetic (BBK) models that incorporate the limiting rate factors for the absorption, distribution, and elimination of chemicals and nanomaterials in human. We seek to generate, interpret, code and integrate data for primary toxicity mechanisms starting from membrane effects and transport after exposure to those differentially modulating critical cell pathway functions prior to final elimination of the insult. Sub-objectives include: 1) developing, building and assessing in silico and in vitro models (cell lines, co- and multi-cell systems) for quantifying toxicity effects. These studies include novel approaches to computational and cell-based validation of key toxicity control mechanisms such as induction or loss of specific pathways or proteins and those incorporating broader rate limiting processes for providing quantitative evaluation of chemical safety. 2) Coding empirical toxicology data from rapidly-acquired, high-throughput and high-content in vitro toxicity studies to aid in developing rate-limiting and mechanistically-based BBK toxicity models, which aid in in vivo toxicity kinetics and response prediction for mammalian systems (an in vitro-to-in vivo extrapolation). 3) Integrating current toxicology modeling with ~omic data sets obtained from current or emerging technologies involving genomic expression through induction, activation and function of cellular proteins. 4) Developing computational approaches to couple in vitro gene expression patterns to protein induction and activation with incorporation of chemical structural activity measures and protein/pathway activity.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.11.B5354: Cell Dynamics and Engineering

Kelley-Loughnane, N.

(937) 255-8607

Biological systems have innate abilities to detect small concentrations of molecules in highly complex backgrounds. These natural sensing elements found offer sensitive and specific binding to these target molecules and provide tools to enhance sensor design. This research involves selection of these sensing elements as well as incorporation of these sensing elements into various detection systems; specifically various cell types, nanoparticles, and transistors. These sensing elements can be composed of oligonucleotides of either RNA or DNA, known as aptamers. The characteristics of these aptamers are being investigated in order to optimize specificity and sensitivity to mission relevant targets. Targets are typically small molecules, which have been traditionally challenging to detect because binding of the molecule to a recognition element often does not exert a detectable change (mass or mobility-based) from the recognition element itself. In the context of AFRL applications, an ideal sensor is target specific, stable under extreme conditions, inexpensive and disposable, and requires minimal components with a rapid readout easily interpreted by an end user of any background. Potential research opportunities for this fellowship include the development of sensing elements in biofilm-forming cellular systems and the determination of the effects of biological matrices on signal output from various biologically enabled sensing systems.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.11.B5357: Lower Torso Human Modeling

Pellettiere, J.

(937) 255-1150

The goal of this research is to investigate the relationship between the pressure distribution of an occupant on a seat surface and the 3-D size, shape and posture of the subject, with the goal of modeling comfortable and effective human postures for design of aircraft crewstations

Objective measurements of crew comfort and its relationship to performance have become increasingly important. One method that is being employed is to measure the cushion and back rest pressure while an occupant is seated. However, these tasks can be quite time consuming and become subject dependent, necessitating the collection of a large sample size in order to measure differences between material properties, contours and other design variables. Finite element modeling of a representative human lower torso with both hard and soft tissues represented should provide some insight into how these design parameters affect the interface pressure distribution. In addition to predicting the interface pressure, the model should be able to provide some insight into the physiological process inside the body as it responds to the applied pressure over time. Questions such as what pressure levels cause blood flow to be restricted over time are important for defining guidelines. Data available for use includes 3-D laser scans of selected subjects, modeling software, and data collected from human subject sit tests.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.12.B0909: Robust Decision Making in Integrated Human-Machine Systems

Gluck, K.

(937) 938-3552

It is clear the traditional boundaries between human and machine are disappearing. The "future" vision of integrated human-machine decision systems is already upon us. Hence, there is escalating pressure on researchers to better understand the basic science of mixed human-machine decision making and make use of this science to develop increasingly robust, automated knowledge extraction tools and intelligent machine-based decision aids that optimize, robustize, accelerate, and adaptively adjust inference, prediction, and decision processes. We are interested in new models and methods for assuring high quality decision processes and outcomes, especially in complex and uncertain dynamic environments.

Keywords: Robust Decision Making; Human-Machine Systems; Knowledge Extraction

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.12.B0910: Generating Depictive and Diagrammatic Representations of Meaning from Linguistic Input

Ball, J.

(937) 938-4065

Current representations of meaning in Natural Language Processing (NLP) systems typically rely on the use of uppercase words like PILOT to represent the concept of a pilot or word senses like pilot_n_1 to represent the first noun sense of pilot (e.g. aircraft pilot, not movie pilot or the action of piloting). These representations are really just alternative language-based forms of representation which fail to adequately capture meaning (Kilgariff, 1997). Until we are able to ground linguistic expressions in representations of perceptually based experience, we will not be able to adequately represent meaning (Barsalou, 1999). As an initial step in this direction, this research will lead to the computational generation of depictive (Lanthrop & Laird, 2009) and diagrammatic (Chandrasekaran, 2006) representations of meaning from linguistic input, starting with linguistic expressions that describe common objects and their spatial relationships, in an aviation scenario. There are two main thrusts for this research: 1) determine how to compose depictive representations from linguistic expressions like “asphalt runway” or “concrete runway” without having to pre-store all possible images; and 2) determine how to diagrammatically represent spatial relationships between the depictive representation of objects.

A follow on goal is to integrate the depictive and diagrammatic representations into the situation model component of the synthetic teammate (Rodgers et al., 2011) to provide grounding for the current propositional representations of objects and situations, and to support reasoning over the depictive and diagrammatic representations.

References:

Barsalou, L. (1999). Perceptual symbol systems. Behavioral and Brain Sciences, 22, 577-609.

Chandrasekaran, B. (2006). Multimodal Cognitive Architecture: Making Perception More Central to Intelligent Behavior. AAAI National Conference on Artificial Intelligence, Boston, MA.

Kilgariff, A. (1997). “I don’t believe in word senses”. Computers and Humanities 31 (2), pp. 91-113.

Lathrop, S. & Laird, J., (2009). Extending Cognitive Architectures with Mental Imagery. Proceedings of the Second Conference on Artificial General Intelligence. Arlington, VA.

Rodgers, S., Myers, C., Ball, J. & Freiman, M. (2011). The Situation Model in the Synthetic Teammate Project. Proceedings of the 20th Annual Conference on Behavior Representation in Modeling and Simulation.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.12.B0911: Efficient Constraint-Based Search Mechanisms in a Cognitive Domain Ontology

Douglass, S.

(937) 938-4057

Air Force Research Laboratory’s Human Effectiveness Directorate cognitive scientists are researching ways to increase the autonomy of cognitive models and agents. One approach to increasing autonomy involves specifying agents with formal representations of themselves, their knowledge, and the affordances of the situations in which they are acting. Researchers leading this approach are developing these representations or Cognitive Domain Ontologies (CDO) using System Entity Structure (SES) theory. SESs are founded on set theory. CDOs are used by autonomous agents to generate effective actions according to the contingencies and affordances presented by the environments they are situated in. These contingencies and affordances are made available as 'constraints' in a CDO. CDO also contains an agent's behavior repertoirre that gets soft assembled per these dynamic constraints. A CDO is the knowledge-base of the agent and contains representations of elements such as the environment, resources, goals, behaviors, etc. The elements of a CDO are linked together by these constaints. Human Effectiveness Directorate researchers are looking for efficient constraint-based search mechanisms to limit the combinatorics of CDO search. The search algorithms will be grounded in AI-based methodologies & Set theory and must be executable on parallel/distributed high performance systems. A key features of the proposed algorithms must be scalability. The algorithms must be able to complete the search process within 0.3-1.0 sec wall-clock time. Performance analayis of algorithms will therefore be a critical aspect of the research. The successful execution of the algorithm will result in a set of cognitive behaviors within the CDO which will prescribe effective action in the situated environment.

Human Effectiveness Directorate researchers are interested in collaborating with academic partners that can contribute to the research and development of contraint-based search algorithms used to process a cognitive domain ontology. Collaborators would design, develop, and analyze knowledge and constraint representation schemes. Collborators would also develop algorithms, implement them in high level programming languages, and execute/evaluate them in high performance parallel/distibuted architectures.

Reference:

Zeigler, B., & Hammonds, P. (2007). Modeling & Simulation-Based Data Engineering: Introducing Pragmatics into Ontologies for Net-centric Information Exchange. Academic Press.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.12.B0912: Developing and Validating Quantitative Theories of Human Cognitive Processing

Gunzelmann, G.

(937) 938-3554

General theories of cognition have been successful in accounting for many important aspects of cognitive processing. At the same time, there are many components of cognition where well-validated theories are lacking. Within the Air Force Research Laboratory’s Cognitive Models and Agents Branch scientists are conducting research to develop quantitative theories in two of these areas – spatial cognition and the impact of fatigue on cognitive processing. In each case, the research focuses on detailed laboratory studies to expose important phenomena combined with the development of computational models to account for the empirical results. We are interested in collaborations with university faculty with expertise in human spatial cognition and fatigue to develop empirical studies and computational models to expand our understanding of these areas of cognitive functioning.

Keywords: Spatial cognition; Sleep deprivation; Fatigue; Computational modeling; Cognitive architecture

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.12.B0913: Competency-based Needs Assessment, Training Design and Delivery, and Performance Assessment Research in Adaptive Environments for Continuous Learning

Bennett, W.

(937) 938-2550

The US Air Force has invested heavily in a training and rehearsal concept called Distributed Mission Operations (DMO) and is working on augmenting and integrating DMO in a new construct called Live, Virtual, and Constructive (LVC) operations. DMO provides the virtual and constructive elements of the new construct while the Air Force is interested in integrating live, operational systems into a managed realistic, adaptive, and affordable environment enterprise for training, rehearsal, test and evaluation. The environment allows local and wide area connection of virtual simulators, constructive models, gaming environments, and relevant live operational systems, such as actual aircraft.

The success of DMO and LVC hinges on several critical research needs that must be addressed. (1) Mission needs and critical knowledge, skills, and experiences must be specified and represented at appropriate levels of analysis. (2) Training objectives and scenarios must be designed to meet these specifications using a principled instructional approach. (3) Construct-oriented, systematic methods to predict, diagnose, monitor, and assess the performance of trainees within environments must be developed and validated. These methods will assist in the prescription of content and remediation within DMO and LVC ops to address knowledge and skill deficits, and to help develop a new class of human performance and machine learning based models. (4) Methods, models, and metrics that are linked to training objectives and that permit routine and longitudinal assessments of individual and team performance and proficiency in synthetic environments and operational settings must be developed and validated. (5) The appropriate identification, integration, and validation of a "mix" or "family" of complimentary trainers and environments that promote, maintain, and/or accelerate learning and performance must be developed. There are also significant research opportunities to develop, implement, and evaluate innovative methods to link and represent core knowledge, skills, and experiences in a way that helps define the environments for learning and which facilitates training development, delivery, evaluation, and transfer.

We are also interested in developing and validating criterion measures related to the impact of DMO and LVC on learning, proficiency, and readiness and that help to quantify intervals necessary for refresher training. There is considerable latitude for research that explores how best to manage some, most, or all of the learning enterprise. Research can include (1) improving the quality and precision of needs assessment, gap, and trade space analyses; (2) training/scenario design, delivery, and management tools; (3) integrating diverse approaches to training such as game-based systems and environments, intelligent and adaptive training environments, and part task trainers; (4) developing methods to improve the credibility and security of learning, data exchanges, and interoperability among the systems; (5) rapid prototyping of novel approaches to human performance monitoring, modeling, assessment, and feedback;(6) developing more precise and generalizable performance measurement and proficiency tracking data; and (7) improving ways to visualize and package feedback data for after action reviews. It may also include application of different approaches/strategies to learning and assessment in a variety of integrated and adaptive environments and contexts.

References:

Pavlova, E., Coovert, M. D., & Bennett, W., Jr. (2012, April). Trust development in computer-mediated teams. Society for Industrial & Organizational Psychology. San Diego, CA.

Alliger, G.M., Beard, R., Bennett, W., Jr., & Colegrove, C.M. (2012). Mission essential competencies: An integrative approach to job and work analysis. In M.J. Wilson, W. Bennett, Jr., S.G Gibson, & Alliger, G.M. Alliger (Eds.). The handbook of work analysis in organizations: The methods, systems, applications, & science of work measurement in organizations. Mahwah, NJ: Taylor Francis.

Arthur, W.E., & Bennett, W., Jr. (2012). Innovations in team task analysis: Identifying team–based task elements, tasks, and jobs. In M.J. Wilson, W. Bennett, Jr., S.G Gibson, & Alliger, G.M. Alliger (Eds.). The handbook of work analysis in organizations: The methods, systems, applications, & science of work measurement in organizations. Mahwah, NJ: Taylor Francis.

Bennett, W., Jr., & Tsacoumis, S. (2012). Research innovations and advances in work analysis. In M.J. Wilson, W. Bennett, Jr., S.G Gibson, & Alliger, G.M. Alliger (Eds.). The handbook of work analysis in organizations: The methods, systems, applications, & science of work measurement in organizations. Mahwah, NJ: Taylor Francis.

Schreiber, B.T., Bennett, W., Jr., Colegrove, C.M., Portrey, A.M., Greschke, D.A., & Bell, H.H. (2009). Evaluating pilot performance. In Ericsson, K. A. (Ed.), The development of professional expertise: Approaches to objective measurement and designed learning environments. New York: Cambridge University Press.

Arthur, W. Jr., Bennett, W. Jr., Edens, P. S., & Bell, S. T. (2003). Effectiveness of training in organizations: A meta-analysis of design and evaluation features. Journal of Applied Psychology, 88, 234-245.

Arthur, W. Jr., Bennett, W. Jr., Stanush, P. L., & McNelly, T. L. (1998). Factors that influence skill decay and retention: A quantitative review and analysis. Human Performance, 11, 57-101.

Alliger, G.M., Tannenbaum, S.I., Bennett, W. Jr., Traver, H., & Shotland, A. (1997). A meta-analysis of the relations among training criteria. Personnel Psychology, 50, 341-358.

Day, E. A., Arthur, W. Jr., Bell, S. T., Edwards, B. D., Bennett, W. Jr., Mendoza, J. L., & Tubre, T. C. (2005). Ability-based pairing strategies in the team-based training of a complex skill: Does the intelligence of your training partner matter? Intelligence, 33, 39-65.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.12.B0914: Advanced Communication Technology

Finomore, V.

(937) 904-7123

The network centric auditory awareness program is an applied research effort for the development and evaluation of an advanced multi-modal communication system. This system utilizes state-of-the-art technology to capture, transcribe, extract, and display voice, text, and annotated images used in team collaboration. The research investigates the information processing capabilities of the human to monitor, process, and respond to high volumes of data, visually and aurally, in a high tempo, noisy environment such as that of Command and Control, Cyber Security, or Intelligence, Reconnaissance, and Surveillance operations. The laboratory can be configured for a single participant up to a five-person team. Communication effectiveness is evaluated by information detection, comprehension, and timeliness of actions. The workload and stress of the participants are also assessed with the use of subjective and physiological measures as well as their ability to interact with the advanced communication system. Visiting faculty members will also have access to panel of 10 - 15 participants who are training listeners as well as a technical support staff to assist in hardware and software development.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.12.B0915: Wearable Interfaces

Finomore, V.

(937) 904-7123

This research effort focuses on developing multi-modal wearable computing technology. The research effort focuses on intuitive displays to increase the situational awareness and reduce the cognitive workload and stress of the operator. This use of advanced visual, 3D audio and haptic displays are developed and tested in an immersive live virtual constructive environment. In addition to the development of the displays to increase mission effectiveness, the physical ergonomics are also a major research and development effort for intuitive human machine integration. The visiting faculty member will have access and be immersed into a multidisciplinary team to assist in their summer research effort.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.12.B0916: Non-Invasive Brain Stimulation to Enhance Cognitive Performance in Air Force Operators

McKinley, A.

(937) 938-3598

The purpose of this project is to evaluate non-invasive brain stimulation techniques and technologies to enhance and optimize human performance. Specifically, the aim is (1) perform basic research into the neurobiological mechanisms of non-invasive brain stimulation responsible for changes in behavioral performance and (2) to conduct applied research in the efficacy of non-invasive brain stimulation techniques, such as transcranial direct current stimulation, as a means to facilitate cognitive skills such as visual search, learning/memory, and attention. The goal is to improve performance through direct augmentation of cortical excitability or activation. All research will be conducted within the cognitive performance laboratory suite, 711 HPW/RHCP, located at Wright-Patterson AFB, OH.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.13.B0913: Human Movement Generation/Simulation

Lochtefeld, D.

(937) 255-2570

Realistic forward kinematics (FK) movement generation/simulation is a challenging problem. For many applications it is sufficient to measure human movement, such as gait, using motion capture technology. Discrete points on the body are used in an inverse kinematics (IK) approach to compute body poses, which can then be used to study human movement and drive the creation of animated characters. Measured movements are inherently more realistic and biofidelic than simulated movement; however, it is often impractical to collect every possible movement for every possible person or character of interest. This research involves generating realistic human movement for a variety of computer animation, biomechanics, and pattern recognition applications. The goal of this work is to develop effective techniques for generating biofidelic movement poses representing a variety of human sizes, shapes, and activities using direct simulation and/or statistical extrapolation of existing measured data (i.e. motion capture data). Additional factors and constraints, such as terrain and environmental interactions, body dress and loading, etc., are of interest. As an integral part of a larger research program, this project will interact with many other research areas, such as human activity modeling, human activity recognition, and markerless motion capture.

Our Human Signatures Laboratory is equipped with whole body scanners, motion capture cameras, video cameras, and other advanced sensor technologies. Software includes tools for human shape and motion analysis. We have built strong capabilities in human modeling, and have large existing databases of human size, shape, and movement patterns. Candidates with demonstrated knowledge and experience in computer animation, human motion simulation and modeling, biomechanics, and statistical approaches are desired. Selected applicants will be expected to work with USAF staff, collaborating university faculty, and contract support staff to develop the methodologies and conduct experiments to validate them if necessary.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.13.B0914: Development of Capture Elements for Sensors

Lyon, W.

(937) 938-3794

Capture elements can be selected and designed to offer sensitive and specific binding to target molecules and provide binding agents for use in sensors. This research involves selection of these capture elements as well as their incorporation into various detection systems; specifically various sensors such microarrays and microfluidic devices. The capture elements can be composed of DNA-known as aptamers or composed of amino acids in the form of short peptides or antibody scaffold constructs. We are investigating the characteristics of these capture elements in order to optimize specificity and sensitivity to mission relevant targets. Potential research opportunities include the development of capture elements such high-affinity bidenate capture elements by producing non-antibody protein-binding reagents using in vitro methods, such as phage and mRNA display, or SELEX to generate high-affinity DNA ligands, use of peptide arrays for selection of peptide as an alternative for screening a library of peptides in phage display, and design of novel scaffold through synthetic chemistry and /or protein design. Once designed transition the capture elements to relevant military sensing platforms. Our research addresses two Air Force thrusts in the areas of Intelligence, Surveillance, and Reconnaissance and human performance which require sensing of physiological and environmental analytes for the greatest impact to the Air Force mission. In addition, our research team partners with AFRL scientists, academia, and industry to improve target detection and assay performance over a wide dynamic range.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.13.B0915: Sensor Platform Development for Rapid to Real-Time Detection in Biofluids

Hagen, J.

(937) 938-2576

The ultimate goal of performance monitoring is to build sensors capable of continuous, real-time analysis of biomarkers for targets indicating stress, fatigue, vigilance, and overall other physiological conditions. Biomarkers found in biofluids can be extremely indicative of physiological state. Traditionally, these biomarkers are assessed with labor intensive biofluid (blood, saliva, urine) sampling and analysis with complex equipment and assays (HPLC, ELISA etc.). To make biomarker tracking a feasible monitoring system, sensor platforms must be developed for rapid to real time analysis. These can be in handheld form factors such as a lateral flow assays or in a wearable form factor such as a transdermal patch.

The objectives of this research are to develop sensor platforms that are amenable to either rapid or real-time analysis of biofluids. Of particular interest are blood and sweat. Sensor platforms should have a small/portable form factor for handheld assays or flexible/wireless capability for wearable form factors. Platforms should be capable of detecting a wide range of molecule types from small <300 Dalton to proteins >3000 Dalton. Additional interest lies in pre-processing of biofluids to increase sensitivity/selectivity of the sensor platform.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.13.B0916: Applied Synthetic Biology for Genetic and Pathway Engineering

Lamkin, T.

(937) 938-3717

Natural biological systems are characterized by exquisite control of highly complex and dynamic systems. Utilizing a limited set of control and functional elements, in combination with chemical and genetic modification, cells possess seemingly unlimited levels of control and regulation to perform diverse yet highly precise functions ranging from self-duplication, self modification, synthesis, metabolism, mobility, sensing, communication and signaling, information exchange and even death, respectively. While fantastic strides have been made in modifying cellular systems, many aspects of cellular engineering remain cumbersome, costly and inaccurate. For example, precise and accurate genetic engineering of single nucleotides within the host chromosome without incorporating exogenous vector sequence remains a major challenge, yet the ability to alter chromosomes at single nucleotide resolution in a fast, efficient and cost effective manner would transform cell biology and cell based technologies. In addition, the ability to deliver various macromolecules to cellular systems in targeted yet not toxic methods remains another critical barrier. Methods to exploit natural mechanisms of cell uptake and directed transport are of interest. Lastly, exploiting natural cellular enzymes and processes to allow high throughput production of natural or engineered macromolecules such as SELEX and phage display have transformed the molecular biology landscape. New high methods to increase the accuracy and speed biological selection and production are also of interest. Selected fellows will work in a highly collaborative and passionate team with USAF and contract scientists and collaborating university faculty to develop the methodologies, perform experiments and validate results.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.13.B0917: Molecular Mechanisms of Host-Commensal Effectors: Genome-Genome Interactions

Lamkin, T.

(937) 938-3717

The human body is heavily populated with thousands of microbial species commonly termed the microbiome. In recent years, the microbiome has been shown to affect diet metabolism, weight, locomotor function, oxygen utilization, immune function, cognition and even radiation protection; all important attributes for human performance. Further, the microbiome is believed to vary significantly from person to person, and possibly, by geographic location, age and even occupation. Recent findings have shown that specific microbially derived molecules have direct signaling effects on human cellular proteins by acting as ligands. That is, the genetic reservoir of one’s microbiota has direct and important effect on human health and performance of the individual. Less widely investigated are what human gene products have direct effector function on microbial populations or specific microbial proteins. Understanding this genome-genome interaction holds great potential for inexpensive and safe enhancement of human performance. In addition, recent data implicate the relative abundance of various species to human health and performance and that relative abundance might act as a tipping point whereby certain populations cause disease and poor performance. Current efforts look to exploit novel models able to decipher the specific human genetic components that regulate the microbiome and its effects on human performance as are molecular mechanisms of genome-genome regulation. Selected fellows will work in a highly collaborative and passionate team with USAF and contract scientists and collaborating university faculty to develop the methodologies, perform experiments and validate results.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.13.B0918: Human Morphology, Modeling, and Discrimination

Lochtefeld, D.

(937) 255-2570

Modern defense applications have become increasingly human-centric, focusing, for example, on identification of individual or group characteristics and behavior. Our current human-centric applications include: simulating realistic human size, shape, and motion for biofidelic computer animations; discriminating among individuals or groups of individuals from a distance (soft biometrics), and expanding understanding of the relationship between human structure and movement. The purpose of this research project is to merge anthropometric and morphological measurement with human modeling and movement analysis. Research goals include statistical analysis of 3-D human scans, variable reduction and identification of key anthropometric variables and shape descriptors, prediction and simulation of human size and shape, and correlation of structural measures with movement parameters. The ultimate goal of the research is to create a 3-D human model that adapts size and shape according to parameters such as weight, gender, age, etc.

Our Human Signatures Laboratory is equipped with whole body scanners, motion capture cameras, video cameras, and other advanced sensor technologies. We have various software tools for human shape and motion analysis. We have built strong capabilities in human modeling, and have large existing databases of human size, shape, and movement patterns. Candidates with demonstrated knowledge and experience in biology or anthropology, computer science, and statistical techniques are desired. Selected applicants will be expected to work with USAF staff, collaborating university faculty, and contract support staff to develop the methodologies and conduct experiments to validate them if necessary.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0837: Strategic Adaptation in Dynamic Non-stationary Environments

Myers, C.

(937) 938-4044

Dr. Chris Myers is conducting research that uses machine learning and control theory techniques to model human performance and decision making within dynamic, non-stationary environments. The work involves both human experiments and computational modeling, with the aim of understanding how humans adapt to changes in complex, dynamic, and collaborative task environments. We are looking for a postdoctoral research associates or university faculty interested in developing optimal models of visual search, multitasking, decision-making, and dyadic collaboration. The ideal candidate will have a background in machine learning, cognitive science/cognitive psychology/mathematical psychology, and/or control theory, and will have

programming experience with R and/or Python. Candidates must be a U.S. citizen or permanent resident.

References:

Chen, X., Howes, A., Lewis, R. L., Myers, C. W., & Houpt, J. W. (2013). Discovering computationally rational eye movements in the distractor ratio task. First Annual Multidisciplinary Conference on Reinforcement Learning and Decision Making, Princeton University, Princeton, NJ, USA.

Myers, C. W., Lewis, R. L., & Howes, A. (2013). Boundedly Optimal Adaptation During Visual Search. 35th Annual Meeting of the Cognitive Science Society. Berlin, Germany.

Veksler, V. D., Myers, C. W., & Gluck, K. A. (2012). An Integrated Model of Associative and Reinforcement Learning. 34th Annual Meeting of the Cognitive Science Society.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0838: Cognitive Modeling of Foundational Human Information Processing Abilities

Gunzelmann, G.

(937) 938-3554

Integrative theories of cognition have been successful in accounting for many important aspects of cognitive processing. At the same time, there are many components of cognition where well-validated theories are lacking. Within the Air Force Research Laboratory’s Cognitive Models and Agents Branch (711 HPW/RHAC), scientists are conducting research to develop quantitative theories in two of these areas that are particularly relevant to Air Force operations – spatial cognition (e.g., Gunzelmann & Lyon, 2011) and the impact of fatigue on cognitive processing (e.g., Gunzelmann, Gross, Gluck, & Dinges, 2009). In spatial cognition, the goal is to develop general mechanisms that can provide an account of the foundational representations and processing that give rise to the diversity of human spatial competence. In fatigue, the research investigates the impact of fatigue on components of cognition, to develop a broad theory that can be used to make predictions about the deleterious effects of sleep loss and time on task on performance in complex, naturalistic environments. In both cases, a combination of empirical research and computational process modeling is used to identify and account for critical phenomena.

Keywords: Spatial cognition; Sleep deprivation; Fatigue; Computational modeling; Cognitive architecture

References:

Gunzelmann, G., & Lyon, D. R. (2011). Representations and processes of human spatial competence. Topics in Cognitive Science, 3(4), 741-759. (DOI: 10.1111/j.1756-8765.2011.01153.x)

Gunzelmann, G., Gross, J. B., Gluck, K. A., & Dinges, D. F. (2009). Sleep deprivation and sustained attention performance: Integrating mathematical and cognitive modeling. Cognitive Science, 33(5), 880-910. (DOI: 10.1111/j.1551-6709.2009.01032.x)

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0840: Neurobiology of Cognitive Performance

Jankord, R.

(937) 938-3144

Performance under stress determines mission effectiveness. The goal of the Neurobiology of Cognitive Performance Team is to understand the biological mechanisms that affect performance. Our work involves physiological and behavioral (attention, anxiety, spatial memory and emotional memory) testing in rodents and examination of the neurobiological changes that occur following treatment. Current projects in our laboratory include a study on neural modulation via transcranial direct current stimulation (tDCS) and a behavioral genetics study on stress resiliency. Our tDCS study seeks to understand the biological mechanisms (gene expression and cell signaling pathways) by which transcranial direct current affects neuronal activity, providing insight into how this methodology affects cognitive function. The behavioral genetics study involves the use of BXD mice, an established genetics reference population, where behavioral outcomes of stress exposure are mapped (QTL mapping) onto defined chromosomal sequences. The goal of the behavioral genetics study is to identify novel genetic factors that modulate performance in a stressful environment.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0841: Nutrition and Cognitive Performance

Johnson, E.

(937) 938-3569

The Applied Neuroscience branch conducts research to evaluate augmentation techniques for optimizing performance. In particular, we are interested in exploring the cognitive benefits of nutritional supplements. We aim to examine the effects of target supplements on performance under stress. We currently utilize a validated rodent model of chronic variable stress to simulate a stressful operational environment. We employ multiple behavioral assessments including those for attention, anxiety, spatial memory and emotional memory and also track physiological and neurobiological changes. Once the safety and benefit of a supplement is validated in an animal model, it will be tested in human subjects in an operationally relevant environment.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0842: Dynamical Team Assessment

Funke, G.

(937) 938-3601

Many (if not most) contemporary air force operations are performed by teams. However, our current understanding of team dynamics (e.g., communication, action, cognition), their objective measurement, and their relation to team performance outcomes is limited. The objective of this research topic is to address these issues across 3 related areas. First, novel metrics that can be employed to quantify the maturation and quality of team dynamics need to be developed and validated. We believe that a particularly promising avenue in this regard involves the application of advanced statistical assessment and classification of team physio-behavioral responses (e.g., communication, kinematics, cardiac rhythm, eye-gaze behavior, brain activity) using nonlinear dynamical analyses. Second, the relations between those metrics and team outcomes must be established. Third, these metrics must be applied to develop and validate real-time classifiers and/or predictors of team state and performance from the identified physio-behavioral responses for use in critical, high-tempo task environments (e.g., cyber defense, remotely piloted vehicle navigation, ISR).

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0843: Engineering In Vitro Multicellular Organ System For High Throughput Screening of Aerospace Toxicology Targets

Hussain, S.

(937) 904-9517

In order to protect the warfighter in operational environments, novel technologies are being developed to enhance the warfighter capabilities. However, prior to implementation of these advancements, there is a need to rapidly and systematically evaluate the potential risk that these advanced nanoscale materials and aerosol chemicals might pose to the warfighter. At this time, due to the large number of chemical substances and the emergence of new materials, in vivo testing would be too lengthy and costly to pursue, yet traditional in vitro methods are lacking. For example, the use of unicellular in vitro models to represent complex tissues, such as the lungs, has received sharp criticism as these models cannot accurately depict how a multi-cellular tissue will respond. Therefore, one of the critical challenges faced in predictive toxicity is the lack of flexible in vitro model systems, which – i) allow for rapid, quantitative, and systematic testing; and ii) mimic the in vivo tissue microenvironment to accurately predict in vivo transport behaviors of chemicals and nanomaterials. However, in vitro cultures are useful for providing a preliminary foundation for studies to assess dosing ranges, probable mechanisms of toxicity, and allow for the refinement of techniques before progressing with costly in vivo studies. In addition, high throughput screening (HTS) using in vitro models can be performed to down select chemical targets for future in vivo studies. The development of microfluidics chambers in conjunction with co-cultures can be used to mimic blood flow and chemical transport. The goal is to develop complex in vitro cell model systems (3D models, organs on chips, airways on chips, etc) that better represent the organ systems found in vivo to further extrapolate in order to adequately assess human health effects of these nanoscale materials and aerosol chemicals.

AFRL/RH 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0844: Biolmolecular Interactions of Nanomaterials: From Safety to Applications

Hussain, S.

(937) 904-9517

Our current research focus is to perform basic studies in order to establish a foundation for understanding the biomolecular interactions of nanomaterials (NMs). The unique quantum properties of NMs strongly influence their physico-chemical properties, conferring electrical, optical and magnetic properties not present in the corresponding bulk materials at a larger scale, making them ideal candidates for novel technologies to aid the AF mission. However, before the full potential of such a technology can be reached, a basic foundation evaluating the biomolecular interactions on NMs in a controlled system must be established. We have developed a characterization paradigm to identify the physical and chemical behavior of engineered NMs in order to link cell responses to specific NM parameters. In addition, a multi cell model approaches are being applied for low level acute and chronic NM studies is used to elucidate the subsequent impact of NMs on cell signaling and gene expression. As NMs possess unique properties, it is highly probable that when they encounter an external field, such as radio-frequency, electromagnetic, or laser, that their enhanced surface energy and reactivity will produce a distinct effect. One major research thrust is to evaluate if simultaneous cellular exposure to NMs and an external field would produce synergistic cellular outcomes, evaluating endpoints on an entire cellular population, protein, and genetic level. In order to evaluate this effect, we have developed a new prototype of non-traditional assays to evaluate the effects of engineered NMs on cellular systems under the influence of non-invasive incidental electromagnetic fields found in every day environments. Since not all NM display toxicological concerns, our focus has also been on utilizing biocompatible NMs for the development of nano-devices. Using gold nanomaterials, graphene, graphene oxide, and novel combinations of these materials, we will establish the groundwork for the biological interactions of NMs which can in turn be utilized to predict the implication of NM exposure, and exploit the benefits of NMs to the AF’s full advantage.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4011: Information Exploitation: Motion Imagery (or Video) Processing and Exploitation

Howlett, T.

(315) 330-4592

Motion Imagery sources include everything from airborne collectors to Youtube. New and innovative technology is required to exploit and extract the relevant information content and manage the whole exploitation process. Visual processing is the focus, but leveraging all aspects of the data is of interest (e.g. audio and metadata) as well as using any additional correlating sources (e.g. reference imagery or coincident sensors). Both semi-automated and fully automated capabilities are of interest. Emphasis will be on overcoming or working around the current limit of computer vision to lead to a useful capability for an AF analyst. Sample topics of interest would be: biologically inspired techniques, scene classification, event detection, object detection and recognition, optimization techniques, Bayesian methods, geo-registration, indexing, etc.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4013: Wireless Sensor Networks in Contested Environments

Huie, L.

(315) 330-3187

Co-advisor:

Horan, V.

(315) 330-3710

Victoria.Horan.1@us.af.mil

Sensor networks are particularly versatile for a wide variety of estimation tasks. Due to the nature of communication in a shared wireless medium, these sensors must operate in the presence of other co-located networks which may have competing, conflicting, and even adversarial objectives. This effort focuses on the development of the fundamental mathematics necessary to analyze the behavior of networks in contested environments. Security for dynamically changing networks is of interest.

Research areas include but are not limited to optimization theory, information theory, detection/estimation theory, and game theory.

Development of new cryptographic techniques is not of interest under this research opportunity.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4021: Information Fusion & Understanding: Anticipation

Salerno, J.

(315) 330-3667

Research in the areas relating to tools that support situation awareness and specifically anticipation of both adversarial and general populace actions/reactions is of interest. Such tools include the ability to combine lower level entities/events into groups and situations, the ability to assess these situations in current time (their impact) and the ability to project the current situation(s) to identify potential threats in our ability to perform our mission. In order to accomplish this, various disciplines from computer and cognitive sciences, artificial intelligence and operations research must be brought together. We seek new and interesting approaches in the following areas:

• Scalable/Robust Model Analysis and Pattern Matching Techniques for providing Situation/Group Recognition and Interpretation (to include such meta-data as uncertainty, severity and perishability)

• Stochastic Modeling Techniques and Sensitivity Analysis Techniques (DOE and DACE) for “large” scale hybrid (systems dynamics, agent-based, procedural, etc.) models

• Development of Situation Assessment Algorithms

• Development of Threat/Impact Assessment Algorithms

• Identification/Recognition of Adversary Intentions

• Identification of “key” differentiating events to support information requirements and collection

• Modeling human behaviors (individual and group) and the environment within which they exist to include such concepts as grievance, risk aversion and satisfaction/content.

• Metrics for Measuring the Performance and Effectiveness (MOE and MOPs) of Situation, Impact/Threat Assessment Techniques in supporting the analyst, operator and decision maker

• Visualization of Complex Relationships

• Verification and Validation of “complex” models

• Architecture/Frameworks that support Interactive Gaming Environments using the knowledge developed to aid Command & Control (C2) operators in Course of Action (COA) development

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4022: Information Fusion & Understanding: Advanced Object Fusion, Identification & Tracking

Alford, M.

(315) 330-3802

A summer faculty researcher is needed to explore new methods of image/video exploitation in large volumes of images and video data. The goal is to characterize events, activities and scenarios in image data containing people (insurgents, for example), vehicles (suspicious), and weapons (Rocket Propelled Grenades – RPGs) immersed in terrain, or among buildings. These images can be readily found on the internet. The ultimate objective is to develop procedures that will go through several images and find all the ones that have a given attribute within them (for example, all these images contain RPGs). Methodologies must be developed in order to automatically determine the contents of the video. First algorithms to recognize objects and associate metadata to those objects are necessary in developing an understanding of imagery contents. Next, by summarizing the detailed characteristics of images and identifying kinematic patterns of those objects, one can develop a context behind object detection and tracking in a video. Further characterization of the objects can be added by querying databases for more detailed descriptions of the objects in the video. The focus will be on the actual video analysis, to assist the human in analyzing the video for patterns of life and normalcy pattern analysis. In addition to object recognition, there is a need to automate scene recognition and understanding. Possible areas of concentration include but are not limited to:

• Ground Truthing of image characteristics

• Discriminative scene understanding (with and without training)

• Space-time scene classification

• Scene categorization

• Annotation, segmentation of images

• Blur compensation (due to camera shake, for example) – this is a pre-processing step

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4023: Information Fusion & Understanding: Knowledge Discovery Metrics

Spina, J.

(315) 330-4032

Research to clearly define performance evaluation metrics for Dynamic Network Analysis applications is of interest. Performance is the degree to which a system or component accomplishes its designated functions within given constraints, such as speed, accuracy, or memory usage. Having a solid suite of performance metrics would yield the advancement of network discovery tools by increasing the effectiveness, efficiency, and usability of analytical programs as well as reducing the amount of time and financial assets spent on their development. Within the intelligence community, there is a severe deficiency in a method or standardprocedure to unambiguously evaluate the performance of network discovery applications. Developing such a process and an initial understanding of these systems would provide a great benefit to the intelligence community.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4024: Information Fusion & Understanding: Natural Language Processing for Text Analytic Applications

Zappavigna, M.

(315) 330-4488

Research in the area of Natural Language Processing to improve text analytic processes is of interest. This will involve examining the current state of the art and practice, consider the shortcomings to these approaches and consider new and novel approaches to address these shortcomings. Researchers will need to consider theories from outside the current area of research and provide methods for implementation and evaluation of performance of these proposed methods. This research would then be applied to improve processes for the following areas but not limited to:

Text Extraction

Semantic Role Labeling

Text Classification

Document Clustering

Indexing and Search

Sentiment Analysis

Event Extraction

Information Retrieval

Multi-source Information Extraction

Multi-lingual Processing of Text

Machine Translation

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4025: Information Fusion & Understanding: Link & Group Understanding

Boulware, D.

(315) 330-3528

AFRL seeks innovative research in the area of link and group understanding, more commonly referred to as social or dynamic network analysis. More specifically, AFRL seeks automated or semi-automated procedures to infer from externally observed data the existence, topology, leadership, and other characteristics of covert social networks including but not limited to the discovery and understanding of unknown activities and associated trends/patterns/relationships. In addition, these techniques should move beyond the limitations of traditional approaches to consider temporal dynamics and\or multi-modal networks and are most interesting when researched in the context of a variety intelligence sources and types and the challenges presented by “Big Data.”

Accuracy of Social Network Analysis and Group Detection in the presence of systematic error

Anomaly detection

Temporal analysis

Temporal data mining

Spatiotemporal analysis

Spatiotemporal data mining

Exploiting attribute and type information

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4033: Information Management: Reactive Service Migration

Milligan, J.

(315) 330-4763

Reactive service migration involves service fault detection and fail-over mechanisms, information service workload migration strategies to relieve overloaded network resources, and pre-positioning of information and services by recognizing the usage patterns of information consumers to anticipate their needs ahead of time. Reactive service migration fail-over mechanisms might make use of workflow compensation, service redundancy, or other exception handling techniques. Workload migration may involve the use of load balancing techniques to achieve optimal resource utilization, maximize throughput, minimize response time, and avoid overload. Pre-positioning of information and services might require the tracking and detection of events or changes in state which indicate an impending user need. In all cases, reactive service migration is concerned with optimizing the quality and availability of information management system services.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4034: Information Management: Enhanced Information Streaming

Kohler, R.

(315) 330-2016

Enhanced information steaming deals with techniques to annotate and otherwise characterize the content of steaming data in order to enrich our ability to interact with the data in ways that go beyond the frames and timelines that current video interfaces impose upon the user. Although frames and timelines are useful notions, they are less well suited for other types of interactions with video. In many cases, users are likely to be more interested such things as motion, action, character, and theme. For example, finding a moment in a video in which an object is in a particular place may be of interest, or the goal might be to compose a still image from multiple moments in a video. Although it is possible to compute object boundaries and to track object motion, typically this information is not captured in a manageable way, nor do present interfaces utilize this information for user interaction. Of interest are ways to embed glyphs and graphics into steaming media (such as descriptive labels, illustrative sketches, path arrows indicating motion, etc.), associating metadata with the indexed content of streaming data, and making this additional information available to consumers for managing the playback and use of streaming information in ways that add value based on specific user needs.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4035: Information Management: Autonomous Decision Making for Policy Enforcement

Mayhew, M.

(315) 330-2898

The biggest threat to mission assurance is the lack of sharing of critical information in a timely and accurate manner within the cross-domain environment. This research will contribute to science of privacy, trust, and security in data dissemination among security domains. This effort requires a fundamental paradigm for decentralized information sharing to overcome existing hurdles in collaboration while considering privacy, integrity, and trust. Research requires integrating research in database systems, quality of service (QoS), privacy, trust, and contextual/situational awareness. Research also involves the discovery, propagation, and aggregation of information shared by multiple participants across domains under varying situations and contexts. The system must adapt to the type, extent, duration, and timing of multiple attacks/failures. Intellectual contributions should include the development of algorithms for proactive dispersion of information, situational-aware paradigm, integrity checks and violator identification methods, information adaptability, and active bundles.

Tasks:

Provide sharing of critical information using the science of trust, privacy, and security in data dissemination among security domains

Design algorithms that evaluate the privacy loss due to disclosure of information to gain trust.

Develop privacy metrics using information theoretic approaches.

Investigate various privacy violator models and user behaviors to be used as benchmarks for testing and evaluation.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4038: Information Management: Data Aggregation & Attestation

Mayhew, M.

(315) 330-2898

A classic concern with automated data handling is the data aggregation issue, also referred to as the ‘sources and methods' problem. That is, a document made up of multiple pieces of information may end up with a final classification higher than any of its constituent parts. Finding methods to assure this does not happen within automated, adaptable services is a major challenge. Further, finding automated or automatable methods to validate and attest that it has not occurred increase the level of difficulty.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4041: Foundations of Trusted Computing

Drager, S.

(315) 330-2735

Research opportunities are available for the design, development and demonstration of foundations of trustworthy computing, including technology, components and methods supporting a wide range of requirements for improving the trustworthiness of computing systems via multiple trust anchors. Research supports security, reliability, privacy and usability leading to high levels of availability, dependability, confidentiality and manageability. Thrusts include hardware, middleware and software theories, methodologies, techniques and tools for trusted, correct-by-construction, composable software and system development. Specific areas of interest include: perpetual model validation (both of the system interacting with the environment and the model itself), trusted evolvability and reduced complexity of autonomous systems; effective trusted real-time multi-core exploitation; architectural security and trust; provably correct complex software and systems; composability and predictability of complex real-time systems; trustworthiness of open source software; scalable formal methods for verification and validation to prove trust in complex systems; novel methodologies and techniques which overcome the expense of current evidence generation/collection techniques for certification and accreditation; and a calculus of trust allowing trusted systems to be composed from untrusted components.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4042: Advanced Computing Architectures: High Assurance Computing

Sifre, W.

(315) 330-2075

The objective of this topic is to investigate the necessary building blocks for high assurance computing environments (environments where compelling evidence is supplied to determine a high level of trustworthiness), including both the underlying hardware and software to support it. Areas of interest include, but are not limited to: (1) the problems and challenges with current processor designs for trustworthiness and their solutions; (2) the problems and challenges with current computer architectures for trustworthiness and solutions to them; (3) the Operating System level constructs, objects, and functions that must be provided to complement the hardware to enable a trustworthy computing base; (4) state of the art software-based assurance designs, methodologies or concepts which are better suited for implementation in hardware than software; (5) research and development for increasing the level of trustworthiness of integrated circuit designs, commodity integrated circuits and currently available systems as a whole; (6) research into and development of solutions to mitigate implications of state-of-the-art commercially available processor architectures (including multi-core, GPUs, FPGAs, etc.) and specially designed processor architectures on Separation Kernels and other secure micro-kernels being developed by real-time operating system vendors for use in environments requiring high assurances; and (7) research and development supporting software, e.g. high assurance middleware technologies, to enhance system interoperability and capability to support cross domain solutions enabling delivery of trustworthy, superior and timely information.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4043: Advanced Computing Architectures: Formal Methods for Complex Systems

Rodriguez, D.

(315) 330-4280

Formal methods are based on areas of mathematics that support reasoning about systems. They have been successful in supporting the design and analysis of systems of moderate complexity. Today’s formal methods, however, cannot address the complexity of the computing infrastructure needed for our defense.

This area supports investigation on new powerful formal methods covering a range of activities throughout the lifecycle of a system: specification, design, modeling, and evolution. New mathematical notions are needed: to address the state-explosion problem, new powerful forms of abstraction, and composition. Furthermore, novel semantically sound integration of formal methods is also of interest. The goal is to develop tools that are based on rigorous mathematical notions, and provide useful, powerful, formal support in the development and evolution of complex systems.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4044: Advanced Computing Architectures: Trusted Software-Intensive Systems Engineering

McKeever, W.

(315) 330-2987

Software is a prime enabler of complex weapons systems and command and control infrastructure and its fungible nature will be key to development of next generation adaptive systems. Yet, software is the most problematic element of large scale systems, dominated by unmet requirements and leading to cost and schedule overruns. As the complexity of today's system lies in greater than 10^5 requirements, greater than 10^7 lines of code, thousands of component interactions, greater than 30 year product life cycles and stringent certification standards, one of the great open challenge questions is how does one bring trust and adaption into the development, verification and validation of software intensive systems?

The objective of the trusted software-intensive systems engineering topic is to develop techniques, methodologies and tools to guarantee trust (as measured by correctness, security, reliability, predictability, and survivability) and migrate the analysis from execution (testing and monitoring) to design (correct-by-construction and formal/security specifications) and development (composition and auto-generation of artifacts). Areas of interest include: techniques to enable trust in model-based software engineering; model-based engineering for predictable software attributes; provably correct code generation; evidence-based software assurance; trusted software and systems composability; modeling, analysis, and verification of autonomous software; mechanisms to fight through software failures; and software comprehension.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4045: Advanced Computing Architectures: Many-Node Computing for Cognitive Operations

Renz, T.

(315) 330-3423

The sea change in computing hardware architectures, away from faster cycle rates and towards processor parallelism, has expanded opportunities for development of large scale physical architectures that are optimized for specific operations. Porting of current cognitive computing paradigms onto systems composed of parallel mainstream processors will continue in the commercial world. What higher cognitive functionality could we achieve if we take better advantage of physical capabilities enabled by new multi-processor geometries?

Perception, object recognition and assignment to semantic categories are examples of lower level cognitive functions. Assignment of valence, creation of goals and planning are mid level functions. Self awareness and reflection are higher level processes that are so far beyond current cognitive systems that relatively little has been done to model the processes. Often, models assume higher cognitive processes will emerge, once the computing system reaches some level of speed / complexity. The problem is that the computational power required exceeded the reachable limit of single processor architectures and probably exceeds the limits of conventional parallel architectures. This topic seeks to enable mid and higher level cognitive function by creation of new physical architectures that address the computation demand in novel ways.

We are interested in developing models for the computational scale of the mid and higher functions and processor / memory node architectures that facilitate cognitive operations by configuring the physical architecture to closely resemble the functional cognitive architecture, e.g., where each node in a network represents and functions as a processor for a single semantic primitive. What new hierarchical architectures could we design for million node systems, where the individual nodes may be small ASPs, with very fast communication between nodes? A project of interest would combine both sides, new algorithms for higher level cognitive functions and new architectures to enable the computation in a realistic time frame. AFRL/RIT has projects on line to enable million node systems.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4046: Advanced Computing Architectures: Nanocomputing

Van Nostrand, J.

(315) 330-4920

Advances in nanoscience and technology show great promise in the bottom-up development of smaller, faster, and reduced power computing systems. Nanotechnology research in this group is focused on the development of crossbar computing architectures which utilize existing nanotechnologies including nanowires, coated nanoshells, memristors, and carbon nanotubes and are scalable to 100x100 arrays. We have a particular interest in the modeling and simulation of architectures that exploit the unique properties of these new and novel nanotechnologies. This includes development of nonlinear sub-circuit models that accurately represent sub-circuit performance with subsequent CMOS integration. Also of interest are the use of nanoelectronics and thermal management techniques using nanotechnologies in 3D computer architectures.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4047: Advanced Computing Architectures: High Performance Computing and Algorithmic Challenges/Solutions in CSE

Seetharaman, G.

(315) 330-2414

Computational science and engineering (CSE) is a multidisciplinary area based on the intersection of computing, sciences, and engineering. The role of computing in a scientific endeavor has changed significantly over the last several decades. It has grown from a tool to analyze experimental results to a vital component for simulation & modeling, experimental instrumentation, large scale experimentation and knowledge discovery. Nearly all facets of complex scientific discovery -- theoretical, experimental, analytic, synthetic and explorative -- involve some form of computation. Rapid advancement in computer architecture, increased sophistication sought by application scientists, steady growth in complex scientific principles sought to be incorporated. The ever increasing scale of required computations demand participation by the domain experts, computer scientists, instrumentation, experimental and operational engineers and the end users, more frequently throughout the design cycle. Such interactions facilitate a more balanced approach to design tradeoff when compared against domain partitioned design and integration of complex systems. Our challenge is to develop the necessary insights and identify the best practices to help foster and accelerate scientific discovery vital for developing affordable high performance war fighting systems in cost and on time with predictable measures of performance and precision -- using our resources: high performance computing systems, instruments, people and infrastructure. A candidate set of problems includes and is not limited to the following list: 1) challenging CSE problems in wide area persistent surveillance; activity analysis in complex multi-dimensional spatio-temporal data-sets; 2) advanced scientific image analysis and knowledge discovery techniques on scalable multi-core high- performance computing architectures; 3) high-performance focused scalable machine-learning algorithms in the context of anticipative computing; 4) software engineering, productivity enhancement tools to catalyze wide spread application of high performance large scale computing in experimental and explorative scientific studies; and, 5) any topic of relevance to Air Force mission involving application science, large scale computing, precision and performance metrics driven operational constraints.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4048: Advanced Computing Architectures: Compressive Sampling

Suter, B.

(315) 330-7563

This topic addresses the theory and applications of compressive sampling. This includes:

◊ Development of a theoretical framework for compressive sampling. One promising direction is

based in part on the study of nonconvex compressive sampling.

◊ Application of computational methods to advance the state-of-the-art in airborne networking. For example, the realization of rank deficient network coding is a recent application of compressive sampling technology to network coding.

◊ Application of compressive sampling to permit novel computational paradigms. Such paradigms show potential for a myriad of applications, including wireless parallel computers.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4049: Advanced Computing Architectures: Quantum Information Processing

Fanto, M.

(315) 330-4455

The topic of Quantum Information Processing is to be focused on Computational Methods and Architectures. It has been well established that a computer based on quantum interference could offer significant increases in processing efficiency and speed over classical versions, and specific algorithms have been developed to demonstrate this in tasks of high potential interest such as data base searches, pattern recognition, and unconstrained optimization.

However the present experimental progress, lagging far behind the theoretical, is at the level of several gates or Q bits. The entangled photon approach to quantum gates including quantum gates, cluster states, and Linear Optical Quantum Computing will be experimentally pursued with particular attention to scalability issues. Experience with generation and detection of entangled photons is essential for this interaction, with parametric amplification a plus.

Theoretical advances will also be pursued with existing and custom quantum simulation software to model computational speedup, error correction and de-coherence effects. Algorithm investigation will focus on hybrid approaches which simplify the physical realization constraints and specifically address tasks of potential military interest.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4051: Cyber Operations: Cyber Defense Research

Debany, W.

(315) 330-4114

Cyber Defense is concerned with the protection and preservation of critical information infrastructures in order to ensure the United States' dependency on cyberspace remains beneficial and does not turn a technological advantage into a vulnerability.

This technology area seeks to: 1) protect our own information space through assurance, agility, denial, deception, and deterrence; 2) enable our system to automatically survive attacks through an innate ability to deal with unanticipated states and environments; 3) provide the means to identify, understand, attribute and localize vulnerabilities before they are exploited, and attacks as they occur; and 4) recover and reconstitute systems, data, and information states rapidly to ensure continuity of operations.

Fundamental research areas of interest within this topic include:

• Methods for mission mapping and dependency analysis within complex systems; going beyond computer and network assurance to mission assurance.

• Design of trustable systems composed of both trusted and untrusted hardware and software; study of virtualization and trusted platforms

• Algorithms and innate mechanisms that enable systems to automatically continue correct operation when presented with unanticipated input or in the face of an undetected bug or vulnerability.

• Techniques that can disrupt an attack during its early stages (reconnaissance, planning, and testing), such as polymorphism, agility, and randomization, at all layers of networking and computer architectures, to reduce the attackers' understanding of our systems and their ability to launch attacks, while maintaining our own situation awareness: “moving target defenses.”

• The ability of information systems to “fight through” attacks, without operator intervention, in a contested environment characterized by “zero day” attacks.

• Examination of assumptions, mechanisms, and implementations of security features that may be adequate for wired networks and devices but provide opportunities for attacks on wireless and mobile systems.

• Theories of complex systems describing interactions of large systems and systems of systems that lead to better understanding of their emergent behaviors during attack and reconstitution; epidemiological models that may be used to predict system responses to Internet worms and coordinated attacks as well as analyses of self-healing and self-restoring systems.

Development of new cryptographic techniques is not of interest under this research opportunity.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4052: Cyber Operations: Achieving Survivability in Cyberspace

Kwiat, K.

(315) 330-4218

We begin by noting that unlike air or space, cyberspace differs in a fundamental way: air and space are natural settings, but cyber is man-made. As a made-made entity, cyberspace is composed of networking and information resources – and is therefore subject to human control. Because of this distinction, the human ability to create and sustain cyber-level linkages can become a venue for malice.

Defense of cyberspace is challenging. The seemingly endless breadth of cyberspace coupled with the technological depth of its composition can divide defensive approaches to be either overarching or highly specific. In order to abstract away details for the purpose of tractability, overarching approaches can suffer because simplistic models for threats, vulnerabilities, and exploits tend to yield defenses that are too optimistic. Approaches that deal with specific threats, vulnerabilities and exploits may be more credible but can quickly lose their meaningfulness as technology changes. Whether approaches are near-or-far term, we see that two underlying attributes remain essential: the ability to survive and the ability to fight through.

The compendium of survival and fight through has, for us, spurred the need for this topic on survivability in cyberspace. Our justification for treating survival and fight-through as inseparable is: although cyberspace’s apparent vastness seems to convey a limitless supply of information and network-related resources, the actual amount of these resources under any single genuine entity’s control is typically very limited. However, an attacker’s aim to overtake resources may not be easily bounded. Thus, driving our goal’s dual survive-and-fight-through make-up is that while the part of cyberspace under single, genuine control is limited, for that same part of cyberspace an adversary’s aim is to maximize control. This dictates that survive and fight-through remain joined. Considered separately, accumulated loss of resources to the adversary will eventually undermine the ability to survive or the ability to fight through – but that is not so for both. That is, surviving an attack by sustaining its damage and fighting through that attack- again and again if necessary - with those remaining resources under the defender’s control allow the system to emerge, and remain, undefeated.

This topic is aimed at covering the breadth of survivability of cyberspace as outline above. Ideas that deal with solving some portion of the overall cyberspace survivability goal are welcome. A potential approach is to transform concepts from the field of fault tolerance to cyberspace survivability. Visiting faculty will perform in-house research as part of the Cyber Science branch’s in-house research effort “Fault Tolerance for Fight Through.”

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4053: Cyber Operations: Information Theoretic Secure Cloud Computing and Cloud Auditing

Han, K.

(315) 330-7986

Cloud computing represents one of the most significant shifts in information technology. However, there are persistent concerns about cloud computing security risks. This research aims to develop secure cloud computing and cloud auditing technologies in order to reduce cloud security vulnerabilities and increase the performance of cloud computing in hostile network environment. Areas of interest include information theoretic security/secure computing applications in DoD Public Key Infrastructure (PKI) environment, secure data management and sharing, efficient metadata management, web 2.0/web 3.0 technology, compression, massive real-time stream data analysis and transmission, Quality of Service mechanism, router-based traffic control, visualization, Wireshark enhancement, cyber threats analysis, automatic cloud auditing, and other cloud security applications including Android Smartphone security.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4061: Command and Control: Modeling and Simulating Intergrated Comand and Control Systems

Trevisani, D.

(315) 330-7311

Military command and control systems are complex, systems of systems that combine numerous applications programs and cross multiple networks, computing systems, and databases. As the Air Force moves toward integrating command and control functions into an integrated command and control system, modeling and simulation offers one approach for exploring new and existing system architectures and system performance. Additionally, modeling and simulation can form the basis for developing methods for exercising and experimenting with integrated command and control systems. Research areas of interest within this topic include:

Methods for developing enterprise models of integrated command and control systems that may include new and legacy components.

Development of integrated command and control system models, such as Unified Modeling Language (UML) models, to identify information exchange requirements and characterize general system performance.

Development of integrated command and control system measures of performance and measures of effectiveness (MOPs/MOEs) that can be obtained via simulation.

Development of integrated command and control system methods to determine Mission Critical Systems on the network.

Methods for rapidly developing simulation scenarios for exercising command and control system models.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4064: Command and Control: Context Sensitive Information Visualization to Enhance Situational Awareness

Moore, J.

(315) 330-4192

Situational awareness is the "fabric" for collaboration and team synchronization in military operations. To be most enabling, its content and the presentation of that content must adapt to the information needs of individual team members, their tasks, and their current situation (context). It must seamlessly bridge the strategic, operational and tactical levels of military operations supporting decisions and actions at all levels. We are looking for researchers to explore the science of adaptive, context sensitive visualization of complex data rich environments, to support team self-synchronization/situation awareness and develop the underlying science needed to engineer future military systems.

Research areas of interest within this topic include:

• Hardware accelerated vector product visualization.

• OpenGL shader abstractions to support reuse

• Network status information compiled into useful metrics.

• Visualization of complex information systems.

• Multi-threaded parallel algorithms for network visualization and layout

• Various techniques for decluttering data and the visualization of that decluttered data.

• Appropriate visualization abstractions that work over WebGL/Javascript or other browser enabled capabilities and langauges

• Composable visualization system interfaces that reduce the amount of user end programming, but still offer rich expressivity

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4065: Advanced Information Visualization and Human Computer Interaction

Jedrysik, P.

(315) 330-2150

In order to provide airmen with an information environment that is dynamic and tailorable based on information needs, we are developing advanced visualizations techniques and interactive displays. Some of our technical challenges include fast access to voluminous dynamic data; high fidelity representations; effective visual interfaces for analyzing large data sets; evaluation metrics for visualization success; effective interaction techniques; integrating large high-resolution displays into a seamless computing environment; and perceptually valid ways of presenting information on a large display. Researchers will investigate effective use of visualization hardware and software. Specific domains include: man machine models; large screen and handheld multi-touch displays; multi-modal interaction; continuous speech; natural language dialogue; eye tracking and gesture interpretation; intelligent interfaces and adaptive mediators; untethered pointing and interaction devices; 3D graphics and visualization; synthetic environments and virtual world C2 applications; display tiling and high resolution media; collaborative interaction and decision making; integrated C2 situational awareness across air, space, and cyber domains; and mission planning and rehearsal.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4072: Connectivity: Management of Tactical Networks

Hadynski, G.

(315) 330-4094

Co-advisor:

Turck, K.

(315) 330-4379

Kurt.Turck@us.af.mil

A primary protocol such as Simple Network Management Protocol (SNMP) is by far the most prevalent method of acquiring network management data in wired networking environments. Conducting effective network management in tactical environments however is a more difficult problem. This research effort focuses on exploring network management protocols and methods to determine what characteristics are most needed to be implemented in the tactical environments.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4073: Connectivity: Authentication in Tactical Airborne Networks

Gudaitis, M.

(315) 330-4478

Co-advisor:

Scatko, T.

(315) 330-4413

Thomas.Scatko@us.af.mil

Future airborne networks may consist of segments employing persistent, high bandwidth links (backbone) and much more dynamic, lower bandwidth links and nodes possibly operating in ad hoc networks. Some nodes will be entering/leaving the network frequently. Techniques for the rapid and reliable authentication of these users need to be developed to allow valid users easy access to the network and its information while keeping out unauthorized users and attackers. Techniques and technologies such as PKI, Zero Knowledge, Identity-based Authentication/Encryption and others need to be examined to determine their applicability in an airborne networking environment.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4074: Connectivity: Wireless Optical Communications

Hughes, D.

(315) 330-4122

Co-advisor:

Malowicki, J.

(315) 330-3634

John.Malowicki@us.af.mil

Quantum communications research involves theoretical and experimental work from diverse fields such as physics, electrical and computer science and engineering, and from pure and applied mathematics. Objectives include investigations into integrating quantum data encryption with a QKD protocol, such as BB84, and characterizing its performance over a roughly 30 km free space stationary link.

Free Space Optical Communication Links: Laser beams propagating through the atmosphere are affected by turbulence. The resulting wave front distortions lead to performance degradation in the form of reduced signal power and increased bit-error-rates (BER), even in short links. Objectives include the development of the relationship between expected system performance and specific factors responsible for wave front distortions, which are typically linked to some weather variables, such as the air temperature, pressure, wind speed, etc.

Keywords applicable to these studies are: quantum cryptography, free space laser propagation, Coherent state quantum data encryption, laser beam propagation through turbulent media, integration of quantum communications system with pointing, acquisition, and control system.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4075: Connectivity: Airborne Networking and Communications Links

Matyjas, J.

(315) 330-4255

Co-advisor:

Medley, M.

(315) 330-4830

Michael.Medley@us.af.mil

This research effort focuses on the examination of enabling techniques supporting potential and future highly mobile Airborne Networking and Communications Link capabilities and high-data-rate requirements as well as the exploration of research challenges therein. Special consideration will be given to topics that address the potential impact of cross-layer design and optimization among the physical, data link, and networking layers, to support heterogeneous information flows and differentiated quality of service over wireless networks including, but not limited to:

Physical and MAC layer design considerations for efficient networking of airborne, terrestrial, and space platforms;

Methods by which nodes will communicate across dynamic heterogeneous sub-networks with rapidly changing topologies and signaling environments, e.g., friendly/hostile links/nodes entering/leaving the grid;

Techniques to optimize the use of limited physical resources under rigorous Quality of Service

(QoS) and data prioritization constraints;

Mechanisms to handle the security and information assurance problems associated with using new high-bandwidth, high-quality, communications links; and

Antenna designs and advanced coding for improved performance on airborne platforms.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4077: Connectivity: Managing Very Large Image Collections

Seversky, L.

(315) 330-2846

This research effort focuses on developing the mathematical tools and algorithms necessary for the management, processing, and analysis of very large image collections. Of particular interest is the ability to exploit common 3D scene geometry described by the image data. Special consideration will be given to topics that propose novel ways for exploiting large image collections for the efficient storage, representation, retrieval, and exploration of the information captured by the data which would not otherwise be possible in the small scale.

Research topics include, but are not limited to image-based modeling, retrieval, and annotation, 3D registration and reconstruction, 3D range and image fusion, scene categorization, and compression. The applicant should have a strong research record in related areas such as geometry processing, computer vision, machine learning, and applied mathematics.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4308: Event Detection and Predictive Assessment in Near-real Time Complex Systems

Blowers, M.

(315) 330-3438

Making best use of multi-point observations and sensor information for event detection and predictive assessment in complex, near real time systems is a challenge which presents itself in many military domains. The first step in tackling these challenges is to analyze and understand the data. Depending on the algorithm used to detect an anomalous event, the nature and extent of variable correlations must be understood. This research will consider methods to quantify the strength of the correlations of input variables to output variables and develop techniques to account for lag times in the data itself. This is no easy task since sensor readings and operator logs are sometimes inconsistent and/or unreliable, some catastrophic failures can be almost impossible to predict, and time lags and leads in real world systems may vary from one day to the next. After detecting where the strongest correlations exist, one must choose a model which can best assess the current conditions and then predict the possible outcomes that could occur for a number of possible scenarios. Scientific issues of interest include, but are not limited to (1) advanced statistical methods to determine dependencies between senor inputs and the combined effect of multiple-sensors (2) adaptive correlation analysis techniques which will evolve to discover new dependencies in time as conditions change (3) adaptive pattern matching methods to take correlated sensor inputs and characterize normalcy and anomalous conditions.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4410: Advanced Computing Architectures: Optical Interconnects

Osman, J.

(315) 330-7671

AFRL's Emerging Computing Technologies Branch offers research opportunities in the area of computer optical interconnects closely coupled in effective ways to processors and/or memories in order to decrease the latency associated with standard interconnects and intra-computer communication. Novel optical interconnect components, architectures, algorithms and subsystems are needed to perform inter-processor, processor to memory and memory to memory interconnects. This includes through open space for compact multiprocessor cores or through optical fibers and/or waveguide for processor to processor interconnects in computational clusters.

Our main area of interest is the design, modeling, and building of interconnect devices for advance high performance computing architectures with an emphasis on interconnects for quantum computing and the use of plasmonic techniques. Current research focuses on interconnects for quantum computing including switching of entangled photons for time-bin entanglement. With its ability to supply a very high field in a very small area, plasmonics is a very promising technique in the quest to make nanoscale optical interconnect components.

Quantum computing is currently searching for a way to make meaningful progress without requiring a single computer with a very large number of qubits. The idea of quantum cluster computing, which consists of interconnected modules each consisting of a more manageable smaller number of qubits is attractive for this reason. The qubits and quantum memory may be fashioned using dissimilar technologies and interconnecting such clusters will require pioneering work in the area of quantum interconnects. The communication abilities of optics as well as the ability of optics to determine the current state of many material systems makes optics a prime candidate for these quantum interconnects.

The objective of this topic is to investigate novel architectures and algorithms for optical processing and interconnects between processors in order to decrease the latency associated with standard interconnects and intra-computer communication. This includes through open space for compact multiprocessor cores or through optical fibers for processor to processor interconnects in computational clusters.

With the increase in density of computational networks there is a need for faster and smarter interconnects between the processors to decrease the latency associated with standard interconnects. Current techniques in interconnecting processors located on separate machines require the interconnections be done through the Ethernet port communication and do not give a direct connection between processors. This requires translation of the processors’ communications into a format suitable for the Ethernet system and the reverse in each unit for a single message. This approach has limited re-configurability and suffers from poor latency. This makes it hard to tightly couple and synchronize parallel processors for processes like scatter-gather aggregation, cache coherency and Global Virtual Time (GVT) determination in Parallel Discrete Event Simulation (PDES).

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4412: Advanced Computing Architectures: Neuromorphic Computing Architectures Research

Thiem, C.

(315) 330-4893

Neuromorphic computing shows great promise in the development of intelligent systems able to imitate natural neuro-biological processes such as reasoning and perception. This is achieved by artificially recreating the highly parallelized computing architecture of the mammalian brain. In particular, neuromorphic computers are suitable for applications in pattern recognition and optimization, i.e. target finding, automated data processing, intelligence analysis, etc. In order to achieve high levels of intelligence within systems, neuromorphic computing exploits the characteristic behavior of novel complex materials and structures with advanced processing techniques to achieve very large scale integration with highly parallel neural architectures. This research effort will focus on mathematical models, computing architectures and computational applications to develop neuromorphic computing processors. Also of interest, is the development of neuromorphic computing architecture software emulation and hybrid VLSI CMOS architectures utilizing nano- scale technologies. Special emphasis will be placed on promising technologies and solutions to satisfy future Air Force needs employing intelligent systems to achieve the desired level of autonomy.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.01.B4413: Advanced Computing Architectures: Quantum Computing Theory and Simulation

Alsing, P.

(315) 330-4960

Quantum computing research involves interdisciplinary theoretical and experimental work from diverse fields such as physics, electrical and computer science, engineering and from pure and applied mathematics. Objectives of AFRL’s Emerging Computing Technology Branch include the development of quantum algorithms with an emphasis on large scale scientific computing and search/decision applications/optimization, implementations of quantum computational schemes with low error threshold rates, implementations of quantum error correction such as topological protection, and the simulation of quantum circuits/computers and quantum error correction schemes with an emphasis on modeling experiments. Topics of special interest include the cluster state quantum computing paradigm, quantum simulated annealing, the behavior of quantum information and entanglement under arbitrary motion of qubits, measures of quantum entanglement, and the distinction between quantum and classical information and its subsequent exploitation.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.11.B4000: Market-Based and Game Theoretic Methods for Resource Allocation in the Cloud

Kwiat, K.

(315) 330-4218

Co-advisor:

Bentley, E.

(315) 330-2371

Elizabeth.Bentley@us.af.mil

Information systems are continually expanding as evidenced by the doubling of Internet connections every year. Similar growth is exhibited by information systems in defense. The Air Force’s mission to fly and fight in Air, Space, and Cyberspace involve the technologies to provide information to the warrior anywhere, anytime, and for any mission. This far-reaching enterprise will necessarily span multiple networks and computing domains that include those that are commercial and exclusively military. As a result, many users with different goals and priorities vie for the communication and computing resources. Managing this vast system to ensure dependable operation that maintains users’ quality of service levels has led researchers to propose computational markets as a means for controlling the allocation of system resources. Economics has always been a factor in engineering. Because it is also the study of resource allocation problems, economics is sought to provide the answer to managing large-scale information systems. By introducing software agents, pricing mechanisms, and game-theoretic mechanisms, the computational economy will strive to exhibit the same phenomena as a real one; it will admit arbitrary scale, heterogeneity of resources, decentralized asynchronous operation, and tolerance of localized failures. These derived benefits are compelling and recent advances in cloud computing have created opportunities for the serious contemplation of building computational markets.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.11.B4001: Multi-User Detection for Random Access in Tactical Airborne Networks

Gudaitis, M.

(315) 330-4478

Co-advisor:

Scatko, T.

(315) 330-4413

Thomas.Scatko@us.af.mil

Existing access techniques in wireless systems are inefficient for large numbers of geographically spaced mobile users. Standard access techniques such Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), or Carrier Sense Multiple Access (CSMA) have limitations that reduce the effective utilization of the wireless data channels. Multi-User Detection (MUD) techniques may allow users to randomly access the channels and receive and detect multiple users through advanced detection and feedback loops in the receiver signal processing. These techniques need to be explored and developed further to evaluate the applicability and effectiveness in tactical airborne networks.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.11.B4002: Interleaving Acquisition and Processing of Geometric Data

Berger, M.

(315) 330-2515

3D geometric data is becoming highly pervasive, both in terms of the acquisition and the analysis of such data. In constrained environments, however, the resources available for acquisition are limited. Moreover, the resulting geometry may be highly imperfect in terms of noise and completeness, necessitating new techniques for analysis.

This research effort focuses on new techniques for the acquisition of 3D geometric data under limited resources, and the analysis of such data. Of particular interest is the interleaving of acquisition and analysis, where an understanding of the environment drives the acquisition process. Topics for geometry acquisition include, but are not limited to: multi-view stereo, photometric stereo, structured lighting, shape from image collections, surround methods for full environment acquisition, as well as the potential fusion of these and other modalities. Topics for geometry processing include, but are not limited to: surface reconstruction, registration, segmentation, scene summarization, large scale and out-of-core management of geometric data, as well as data-driven analysis of geometry. Applicants should have a strong background in geometry processing, computer vision, machine learning, and applied mathematics.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.11.B4004: Advanced Computing Processors Information Management

Ramseyer, G.

(315) 330-3492

As the number of computing processors is increased for most applications, a situation is reached where processor information management becomes the bottleneck in scaling, and adding additional processors beyond these number results in a deleterious increase in processing time. Some examples that limit scalability include bus and switch contentions, memory contentions, and cache misses, all of which increase disproportionally as the number of processors increase. The objective of this topic is to investigate existing and/or to develop novel methods of processor information management for multiprocessor and many-processor computing architectures that will allow for increased scaling.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.11.B4005: Processing Exploitation and Dissemination of Video

Seetharaman, G.

(315) 330-2414

We are facing a steady growth in ubiquity and diversity of video data in addition to an explosive growth in volume of data. Both the latitude of images that can be sensed, access to harvestable opportunistic data, crowd sourced data, and archived images add a new dimension to the scope and precision of extractable information. This unprecedented growth offers ability to mine information that may be of critical import to various tasks we undertake. Existing methods on video analysis are not fully integrated to exploit the potential value and impact of wide spread, sparse, and piece-wise dense multi-modal data sets with imprecise meta-data and loosely coupled links to unreliable and often undependable related information. Various techniques ranging from motion analysis, location aware techniques, context and content based processing, storage, dissemination techniques, scalability and performance oriented algorithm development techniques, and highly-scalable machine learning techniques are of interest. These include, classic video processing techniques, emergent compressive sensing frameworks, wide-area motion imagery, high-definition location-tagged imagery, content based image retrieval, context based performance improvements, and embedding and exploitation of higher dimensional manifolds, and innovative machine learning algorithms such as support vector machines, share-boost etc. Although we are looking for fundamental works in pixels to perception chain, innovative methods to address performance barriers in mapping new and established insights on to a data to decision processing chain is of equal importance. Algorithm development, prototyping and bench-marking of emergent and established algorithms for capturing, characterizing, indexing, archiving extractable information from video, including such metrics on precision, performance, scalability and versatility are within the scope of this thrust. Importance will be given to context and content awareness, performance, versatility, scalability, affordable high-performance and embedded- computing focused research.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.13.B0905: Enabling Robust Autonomy

Loscalzo, S.

(315) 330-2963

Autonomy has been identified in the recent Air Force Technology Horizons report as one of the key technologies needed to support the USAF over the next 20 years. Many research challenges must be addressed before autonomous systems can be reliably deployed in practice, and AFRL/RI is broadly interested in addressing those challenges that occur as a result of the presence of massive amounts of data being available to an autonomous agent. Big Data problems can occur in autonomous systems as a result of being informed by many sensors or by attempting to leverage previously gathered information to better adapt to future situations, as well as from a variety of other causes. Generally, AFRL/RI is interested in topics from the knowledge discovery from data and machine learning fields that can help scale autonomous agents to real-world problems, or make complex problems more tractable for agents. Specific topics include:

• Efficient problem representation - Reinforcement learning (RL) is seen as a key enabling technology of autonomy. One obstacle in the path of robust autonomy is the difficulty that RL has in scaling up to environments described by many variables. It may be the case that these variables do not characterize the most efficient space to learn in due to redundant or irrelevant information captured by the given variables. For this reason, we are interested in novel techniques that can reduce the effective size of a problem, such as feature selection or extraction, state abstraction or aggregation, and problem decomposition.

• Anticipating versus Reacting - Conditions in real-world environments are dynamic - threats emerge and may be neutralized, capabilities appear without warning, etc. - and robust autonomous agents must be able to act appropriately despite these changing conditions. To this end, we are interested in identifying events which signal that a change must be made in agent behavior by mining past data from a variety of sources. This capability would allow agents to learn to anticipate and plan for scenario altering events rather than reacting to them after they have already occurred.

• Safe Exploration - In machine learning contexts (e.g. RL) there is a trade-off between an autonomous agent exploiting what it has already learned versus exploring the environment with the expectation of improving its behavior. Exploration can be dangerous, however, since exploring in a critical region of the environment can lead to a catastrophic failure of the agent. We are interested in developing techniques that can guarantee safe exploration in real-world scenarios, or efficient exploration policies that minimize the chances of a catastrophic failure while still allowing an agent to improve towards optimal behavior.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.13.B0906: Multi-agent Planning for Autonomous Support in Command and Control

Gemelli, N.

(315) 330-3252

In an effort to support the Air Force’s mission to develop robust autonomous Command and Control systems, we are interested in furthering the identification of problems, and development of solutions, in multi-agent planning. Multi-agent planning involves the development and coordination of individual plans by a collection of distributed agents to accomplish assigned goals. We are interested in multi-agent planning solutions in resource-constrained environments (processing power and communication restrictions) with time-sensitive goals. We have identified three broad topic areas of interest we would like to investigate in attempt to provide a multi-agent planning capability for autonomous C2.

• Plan de-confliction – The initial phases of planning are the most important part of the planning process. Local planning by distributed agents may be efficient, but often leads to the need for plan conflict resolution and negotiation once partial plans are aggregated. Finding effective ways to reduce the occurrence of initial plan conflicts as well as minimize the amount of time required to de-conflict a set of partial plans is critical to time sensitive mission requirements. We are interested in multi-agent solutions to initial (partial) plan selection, fast plan de-confliction, and plan merging for large plan assembly.

• Plan deviation recognition and repair – Once a plan is generated and conflicts are resolved, there exists the potential for a plan to begin to deviate from its initially intended goal(s). Given that the intent of a plan is common knowledge amongst all agents, quick recognition of a plan off course and the generation of potential plan repair options will ensure that even if/when a plan begins to deviate; there will be online methods of providing correction that will not require a complete re-planning phase. We are particularly interested in methods for the local identification of plan deviation and development of local plan repair.

• Fast plan generation through Swarm intelligence – As time is a critical factor in many planning situations, we are interested in alternative methods for generating quick planning solutions that can satisfy the intent of the plan, even if they are not optimal. As multi-agent planning is inherently distributed and potentially large-scale, biologically-inspired swarm intelligence could play a role in meeting the demands of resource constrained, time sensitive planning and tasking. Simple, efficient, actions coordinated across many individuals have the potential to produce complex, goal-oriented, group behaviors using reduced processing power and less time. Exploring such systems to determine their adaptability and applicability to military planning could lead to the development of new planning paradigms for autonomous systems supporting Command and Control (C2).

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.13.B0907: Complex Network Inference

Seversky, L.

(315) 330-2846

Co-advisors:

Huie, L.

lauren.huie@us.af.mil

Berger, M.

matthew.berger.1@us.af.mil

Recent advances in sensing technology have enabled the capture of dynamic heterogeneous network data. However, due to limited resources it is not practical to measure a complete snapshot of the system at any given time. This topic is focused on inferring the full system or a close approximation from a minimal set of measurements. Relevant areas of interest include matrix completion, classification, clustering, and ranking of single and multi-modal data, all in the context of active learning and sampling. Also of interest are topological methods such as robust geometric inference, statistical topological data analysis, and computational homology and persistence. Candidates should have a strong research record in these areas.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.13.B0908: Causal Information Retrieval

Verenich, E.

(315) 330-2766

Standard Information Retrieval (IR) models use document and query representations to satisfy users’ information needs. Boolean and vector space models match queries and documents using formally defined, but semantically imprecise, calculation of index terms. Given only the query representation, the system is unsure of the information need. Given a query “causes of inflation,” for example, neither the query nor the document representation of standard IR models communicate to the system the need to assign higher weights to the most likely causes of inflation, which in this case a human would see as the most probable information need of the query. “Can a probabilistic causal model format be used to communicate or better define information needs of both the document and query representations?”

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.13.B0910: Cognitive RF Spectrum Mutability

Matyjas, J.

(315) 330-4255

Co-advisor:

Gudaitis, M.

(315) 330-4478

Michael.Gudaitis@us.af.mil

When considering operations across terrestrial, aerial, and space domains, effective use of the limited Electromagnetic Spectrum (EMS) for a multitude of purposes is critical. The combined pressures of increasing demand for services and less available bandwidth for all make it imperative to develop capabilities for more integrated, flexible and efficient use of available spectrum for all functions (communications, radar, sensors, electronic warfare, etc.) across all domains (terrestrial, aerial, and space). In recognition of the need for affordable, multi-functional software-defined radios with spectrum agility and survivability in contested environments, this research effort seeks lightweight Next-Generation Software Defined Radio (SDR++) architectures and advanced waveform components for affordable solutions based on COTS and non-development items (NDI), relevant operational security, and appropriate trades in levels of software & hardware roots-of-trust. This will create an innovative high-performance flexible radio platform developed to explore the use of next-gen cognitive, smart-radio concepts for advanced connectivity needs across heterogeneous waveform standards and multiple EMS use-cases; while meeting tighter cost budgets and shorter time-to-fielding. The technology developments will support global connectivity and interoperability via multi-frequency/band/waveform reprogrammable radios for networked, multi-node aerial layer connectivity & spectrum mutability, providing system composability and engineered resilience.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B0826: Dynamic Resource Allocation in Airborne Networks

Bentley, E.

(315) 330-2371

From the Air Force perspective, a new research and development paradigm supporting dynamic airborne networking parameter selection is of paramount importance to the next-generation warfighter. Constraints related to platform velocity, rapidly-changing topologies, power, bandwidth, latency, security and covertness must be considered. By developing a dynamically reconfigurable network communications fabric that allocates and manages communications system resources, airborne networks can better satisfy and assure multiple, often conflicting, mission-dependent design constraints. Special consideration will be given to topics that address cross-layer optimization methods that focus on improving the performance at the application layer (i.e. video or audio) and/or examine the spectral utilization problem in cognitive networks.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B0827: Enhanced Exploitation and Analysis Tools

Blasch, E.

(315)-330-2395

Research in data, sensor, and information fusion supports numerous applications; however, the ability of techniques and tools to support operational needs is based on user attributes (e.g., The Data Fusion Information Group Model of Level 5 Fusion “User Refinement”). A current need is to understand how different tools such as target trackers, semantic extraction engines, and data exploitation methods support users. Research questions include advanced computing, analytics, security, data visualization, and human-machine interaction. Various applications such as full motion video (FMV), hyperspectral imaging (HSI), high-range resolution radar (HRR), satellite imagery, wide area motion imagery (WAMI), text, and Open Source Intelligence (OSINT) require different techniques to balance user interaction and machine exploitation. The technical challenge is to achieve a robust balance between computational effort, timeliness, and performance between databases, users and exploitation tools. We are interested in the academic and application problems that bridge the balance for unstructured scene perception, semantic understanding, and data control over multiple spatial, temporal, and frequency scales. The detection, characterization, and learning of patterns that impact exploitation, tracking, prediction, and validation of potential targets for activity-based intelligence will be of interest. Various analytical and practical tools that capture autonomous decision making, build assistive tools, and facilitate reporting will be considered.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B0828: Combinatorial Designs for Key Distribution

Horan, V.

(315) 330-3710

Key pre-distribution schemes are required for certain kinds of wireless networks. One approach is to utilize combinatorial design theory as a means of developing a set system of keys with a specified amount of overlap. These sets of keys are then deployed with the nodes in the wireless network. Thus the robustness and connectivity of the network depend solely on the key pre-distribution scheme employed. Combinatorial designs provide a method for addressing these concerns in a scalable manner.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B0829: Secure Processing Systems

Rooks, J.

(315) 330-2618

The objective of the Secure Processing Systems topic is to develop hardware that supports maintaining control of our computing systems. Currently most commercial computing systems are built with the requirement to quickly and easily pick up new functionality. This also leaves the systems very vulnerable to picking up unwanted functionality. By adding specific features to microprocessors and limiting the software initially installed on the system we can obtain the needed functionality yet not be vulnerable to attacks which push new code to our system. Many of these techniques are known however there is little commercial demand for products that are difficult and time consuming to reprogram no matter how much security they provided. As a result the focus of this topic is selecting techniques and demonstrating them through the fabrication of a secure processor. Areas of interest include: 1) design, layout, timing and noise analysis of digital integrated circuits, 2) Implementing a trusted processor design and verifying that design, 3) Selection of security features for a microprocessor design, 4) verifying manufactured parts, and 5) demonstrations of the resulting hardware.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B0830: Nonlinear Computing Systems and Architectures

Rose, G.

(315) 330-2562

As semiconductor technologies continue to scale further into the nanometer regime it is important to study how non-traditional computer architectures may be uniquely suited to take advantage of the novel behavior observed for many emerging technologies. Nonlinear computing systems represent a type of non-traditional architecture encompassing evolutionary systems where the dynamics of evolution from one operational state to another are nonlinear. An example nonlinear computing system is the chaos computer where chaotic oscillators are used as complex logic components in the construction of the overall system. Such nonlinear computing systems hold great promise for several applications including dynamic reconfigurable computing, computational intelligence, and security.

Nonlinear computing systems research requires interdisciplinary work from several diverse fields such as physics, electrical and computer engineering, computer science and from both pure and applied mathematics. Interest in this topic includes the study of models and prototypes of nonlinear computing systems in terms of a variety of performance metrics such as speed, energy consumption, accuracy and security. One particular interest is the investigation of the use of nonlinear computing systems for improved security; for example, mitigating side-channel attacks and/or providing new avenues for code obfuscation. This would include the study of potential tradeoffs between security and other performance metrics such as energy and delay. Other potential uses of nonlinear computing artifacts of interest to this research include the construction of reconfigurable computing platforms, neuromorphic systems, and new approaches to evolutionary computing, to name a few. Furthermore, from a more theoretical perspective, there is interest in developing a better understanding of the underpinnings of nonlinear systems and their relationship to complexity driven computation. Building on such theoretical work, one could also study how design choices can be used to either encourage or discourage the promotion of complexity from lower level components to higher levels of abstraction.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B0831: Edge of Chaos Computational Architectures and Cortical Networks

Wysocki, B.

(315) 330-7109

Recent advancements in nanoelectronics, photonics, neuromorphic systems, and cognitive neuroscience are enabling the development of radically different computational architectures based on reservoir computing concepts. Such systems are theoretically capable of solving the toughest temporal/spatial classification and regression problems with Air Force applications focused on increased system autonomy and perception. This research explores a new class of computationally intelligent processers governed by the nonlinear dynamics within oscillating optical or electronic reservoirs. The nonlinear dynamics and delayed feedback (short term memory) of reservoirs enable networks to mimic transient neuronal responses and to project time dependent input into high dimensionalities for categorization by an outside classifier. Such hardware based reservoirs can operate near the edge of chaos providing extreme sensitivity to input variations for increased degrees of separability between input signatures. In this context, the reservoirs function as time delayed recursive networks that utilize feedback as short term dynamic memory for the processing of time-series input signals. These systems offer potentially disruptive capabilities in real time signature analysis, time-series predictions, and environmental perception for autonomous operations. Interests associated with this topic include; exploration of the required properties and associated mechanisms to build efficient reservoirs, system modeling, spike-timing-dependent plasticity (STDP), and cortical architectures, with emphasis on bio-inspired computational schemes based on the physics of near chaotic systems.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B0832: Towards Precise Low Level Program Analysis

Yan, L.

(315) 330-2756

Program analysis has traditionally been separated into two categories – dynamic and static. In dynamic analysis the sample under test is executed and its runtime behavior is analyzed. In static analysis, the sample is analyzed at rest. The main benefit of static analysis is code coverage, (e.g., the full control flow graph of a sample can be built) however, its main disadvantage is the lack of runtime or concrete data values. Conversely, the advantage of dynamic analysis is the availability of concrete information and the disadvantage is the lack of coverage. Thus, program analysis in practice is likely to use both static and dynamic techniques.

There are also different dimensions to program analysis. Analysis-granularity is one of them. For obvious reasons, analyzing a program at a high level representation (e.g., source code) can benefit from the available contextual information which is lost when a program is analyzed at a lower level (e.g., assembly). This loss of high level information, in turn, leads to a loss of precision (i.e., increase in false positives). Unfortunately, low level analysis is the only viable approach for many applications. For instance, malware samples normally arrive as binaries and not as source code.

The main goal of this topic is to investigate techniques that can be used to increase the precision of low level analysis. To put it differently, how can we make low level analysis as precise possible with the upper bound being high level analysis? The proposed work should initially focus on individual sub problems in program analysis – information flow, control dependency, etc.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B0833: Programming for Emerging Nonlinear Computer Architectures

Yan, L.

(315) 330-2756

Co-advisor:

Rose, G.

(315) 330-2562

Garrett.Rose.1@us.af.mil

Modern computer architectures are separated into multiple abstraction layers: hardware, firmware, operating system, middleware, applications, etc. In this organization, low level details are abstracted away from higher level users. For instance, application programmers can focus on designing and implementing new algorithms and functionality without having to worry about the intimate details of instruction set architectures, physical memory management, communications protocols, etc. While this organization has been great for implementing everyday applications, the abstraction layers have actually been a hindrance for specialized applications. In order to attain high algorithmic efficiency, scientific computing practitioners must understand the details of available instruction sets (e.g., MMX and SSE), pipelining, cache design and memory bus bandwidth, amongst others. Similarly, security implementers must be cognizant of any special hardware (e.g., TPM chips and AES-NI extensions) to attain high performance and security. The same applies to nonlinear computing as well. In other words, the abstraction layers do not exist for these specialized applications and neither do their benefits.

However, as performance and security have become mainstream problems, new middleware and programming paradigms have been introduced. For example CUDA and OpenCL are two new programming paradigms that help abstract away some of the details of stream programming. Users write code in a C like language, and the compiler takes care of data organization and stream processor allocation. Hadoop is another example of a middleware that abstracts away the details of parallel and distributed programming and exposes the much simplified map-reduce algorithm.

This topic seeks to research and develop techniques and tools for abstracting away the details of a nonlinear computing system. An example topic of interest is compilers or middleware that abstract away the dynamic nature of chaos computers. In this way, if chaos computing is used for code obfuscation, the compiler is, in essence, a program obfuscator. A second example is model based design and implementation for nonlinear computing components. In this example topic, the different nonlinear computing instantiations are formally modeled. These models are then used to compose applications and runtime code that abide by user specifications.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B0903: Advanced Event Detection and Specification in Streaming Video

Aved, A.

(315) 330-4320

Video is leveraged for a variety of monitoring tasks, ranging from the monitoring of bridges, traffic and the interior of large buildings, to providing situational awareness in real time via unmanned aircraft. Presently such systems need to be monitored by human operators who must maintain high levels of constant vigilance to search for critical events that occur infrequently. The goal is to develop algorithms that operate in real time (or near real time) that can detect and characterize both short-term events (recognized in a single or few consecutive frames of video) and/or long-term activities (composed of one or more correlated events). Also of interest are enabling technologies and techniques; to include the specification of events via high level query languages, query optimization, multi-INT data fusion (e.g. to include combining multiple modalities of data into a stream amenable to off-line search and retrieval or subsequent processing in a cloud computing environment). Architectures of interest include both CPU and GPU, as well as cloud/distributed systems and mobile devices.

AFRL/RI GRIFFISS BUSINESS AND TECHNOLOGY PARK

SF.20.14.B1017: Application of Game Theory and Mechanism Design to Cyber Security

Kamhoua, C.

(315) 330-2686

Cyber attacks pose a significant danger to our economic prosperity and national security whereas cyber security seeks to solidify a scientific basis. Cyber security is a challenging problem because of the interconnection of heterogeneous systems and the scale and complexity of cyberspace. This research opportunity is interested in theoretical models that can broaden the scientific foundations of cyber security and develop automated algorithms for making optimum decisions relevant to cyber security. Current approaches to cyber security that overly rely on heuristics have been demonstrated to have only limited success. Theoretical constructs or mathematical abstractions provide a rigorous scientific basis for cyber security because they allow for reasoning quantitatively about cyber attacks.

Cyber security can mathematically be modeled as a conflict between two types of agents: the attackers and the defenders. An attacker attempts to breach the system’s security while the defenders protect the system. In this strategic interaction, each agent’s action affects the goals and behaviors of others. Game theory provides a rich mathematical tool to analyze conflict in strategic interaction and thereby gain a deep understanding of cyber security issues. The Nash equilibrium analysis of the security games allows the defender to allocate cyber security resources, understand how to prioritize cyber defense activities, evaluate the potential security risks, and reliably predict the attacker’s behavior.

Securing cyberspace needs innovative game theoretic models that consider practical scenarios such as: incomplete information, imperfect information, repeated interaction and imperfect monitoring. Moreover, additional challenges such as node mobility, situation awareness, and computational complexity are critical to the success of wireless network security. Furthermore, for making decisions on security investments, special attention should be given to the accurate value-added quantification of network security. New computing paradigms, such as cloud computing, should also be investigated for security investments.

We also explore novel security protocols that are developed using a mechanism design principle. Mechanism design can be applied to cyber security by designing strategy-proof security protocols or developing systems that are resilient to cyber attacks. A network defender can use mechanism design to implement security policies or rules that channel the attackers toward behaviors that are defensible (i.e., the desired equilibrium for the defender).

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.01.B9832: Stimuli-Responsive Optical and Adaptive Materials

White, T.

(937) 255-9551

Stimuli-responsive materials are essential for the realization of “smart”, highly engineered technologies needed in aerospace and countless other application areas. Towards this end, our group is pursuing the development of novel stimuli-responsive optical and structurally adaptive materials. Topical areas currently under examination are liquid crystals, liquid crystal polymer networks (glasses and elastomers), and shape memory polymers. Novel methods of triggering responses in these materials exploit a range of stimuli including thermal, electrical, and light.

Keywords:

Liquid crystals; Liquid crystal polymers; Optics; Adaptive; Polymers; Electro-optics; Polymerization processes; Polymeric films; Photopolymerization

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.06.B4279: Towards Bottom Up Meta Materials: Hetero-Assemblies of Functional Nano-Structured Hybrids and Polymers

Vaia, R.

(937) 255-9209

The ability to engineer the performance of a material system is directly related to the precision of the techniques available to prescribe the structure and arrangement of its constituents (i.e. its architecture). Many emerging technologies require organic-inorganic compositions (30-60%) and architectural refinement that challenge traditional blending concepts, as well as demanding throughput and acreage that challenge emerging high-energy lithography and deposition technologies. Demands for such films and bulk materials range from high performance dielectrics, human performance sensors, and energy storage, to plasmonics, optical metamaterials, nonlinear-optical devices, and compliant conductors.

Efforts focus on establishing the principles underlying processing-structure-property relationships through a multi-disciplinary team that combines synthesis, processing, simulation, physics and concept demonstration. The goal is to understand the factors limiting structural perfection, and thereby establish predictability between the design of the organic-inorganic building block and the properties of its resultant assembly and device. Principle interests include inorganic nanoparticle synthesis, interface modification with a focus on the biotic-abiotic, self- and directed assembly, plasmonics, electro-optical performance, mechanical adaptivity, autonomic response and process compatibility with print-to-device technologies. Techniques include polymer physics, scattering (optical, x-ray, and neutron including synchrotron radiation experiments for real-time characterization), electron microscopy, atomic force microscopy, standard linear and nonlinear optical characterization, bulk and surface spectroscopy, modeling, processing, and synthesis.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.06.B4956: Molecular and Polymeric Materials: Modeling and Synthesis

Dudis, D.S.

(937) 255-9148

Our current efforts are focused on corrosion sciences in efforts to better understand, predict, and manage corrosion and materials degradation. Various forms of soft matter display useful conductive, semiconductive, electro-optic, and nonlinear optical properties. We are interested in these materials for a variety of applications including advanced displays, fuel cells, photovoltaics, batteries, and sensors. We apply a variety of scientific disciplines to understand and develop new materials broadly defined as conductive polymers, molecular electronics, or nanomaterials. We utilize state-of-the-art computational methods ranging from correlated ab initio first principles quantum methods to classical molecular dynamics simulations to understand and design these materials. On the experimental front, we employ modern synthetic methods to prepare and characterize such materials. We also study advanced materials concepts for structural and aerospace materials, and are focusing on bioinspired concepts related to energy harvesting, transport, transformation, storage, as well as molecular based actuation. Opportunities exist to apply advanced computational chemistry and molecular modeling methodologies employing superb high-performance computing capabilities to model and understand phenomena as well as to design materials. Opportunities also exist to synthesize and characterize unique molecules and polymers, as well as supramolecular architectures, having promising electronic, optical, or structural properties.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.06.B4968: Computer Simulations & Vibrational Spectroscopy for Design of Improved Aerospace Materials

Berry, R.

(937) 255-2467

Research relates to current and prospective interests in design of improved materials for aerospace applications. Calculations include electronic structure theory, equilibrium molecular dynamics, nonequilibrium molecular dynamics (shear simulations), chemical kinetics modeling, and density functional theory calculations under three-dimensional periodic boundary conditions. Properties of interest include computation of physical characteristics (e.g., glass transition/melting temperature, viscosity), elucidation of reaction pathways and determination of reaction mechanisms, prediction of interfacial phenomenon, estimation of tribological behavior of coatings, and calculation of mechanical properties.

Projects of interest are described below:

(1) We are designing improved 2-photon absorbing (TPA) chromophores. TPA chromophores provide spatially localized cure of polymeric coatings with enhanced depth penetration. Potential DOD applications of this technology include optical limiting, three-dimensional data storage, rapid repair, and lithographic micro fabrication. Ongoing investigations have focused on improving 2-photon cross-section and photostability. Our main objectives are to computationally predict the physical and mechanical characteristics of the TPA chromophore formulations. Force field parameters required for the simulations that are currently missing in the commercial software are being derived under a cooperative research and development agreement (CRADA) with Accelrys, Inc.

(2) Efficient flexible-thin-film photovoltaic (FTFPV) cells are based on deposition of thin layers of amorphous or polycrystalline semiconductors onto thin polymer or metal foil. The proposed development of next-generation photovoltaic cell technology combines the attributes of high-efficiency multijunction solar cells with the lightweight, low-cost, and radiation resistant nature of FTFPV. Nanocrystals can be used for the formation of the transition layer, which is lattice matched in order to provide a suitable substrate for multijunction voltaics. The coalescence of nanocrystals into large grains can be controlled using the technique of zone melting recrystallization. The resolidification behavior of the nanocrystals after melting will depend on their size and the temperature profile. Molecular dynamics simulations using an empirical potential function will be conducted to study the coalescence of isolated nanoparticles. The interaction of molten material with the previously solidified crystal will also be investigated computationally. The results of the simulations will be compared with experimentally determined melting temperatures as a function of particle size distribution. The molecular dynamics results will be input to mass transfer and heat flow models that will determine process parameters for the zone melting recrystallization operation.

(3) Design limits for the mechanical behavior of polymers: Molecular dynamics simulations to evaluate the specific stiffness as a function of specific strength of polymers and the ability of various additives (i.e. buckyballs, hyperbranched molecules, nanotubes) to impart strength and lightweight properties.

(4) Vibrational spectroscopy (Raman and infrared): Spatial characterization of nano- and bio-materials.

Keywords:

Nanoparticle; Bio-inspired; Bio-panning; Bio-mineralization; Force field; Ab initio; Molecular dynamics; Density functional theory; Mechanical properties of polymer-composites; Mechanical properties of thermoset polymers

Eligibility

Citizenship: Open to U.S. citizens and permanent residents

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.06.B5508: Physics of Nano and Hetero-structured Materials Response

Roy, A.K.

(937) 255-9034

The innovative utilization of materials heterogeneity and efficient design of materials interface, especially at the atomistic and nano scale, offers new opportunities in tailoring properties (electronic, thermal, chemical and mechanical) of materials and influencing device performance.. Our emphasis is in understanding the physics of materials response at the atomic scale and linking that to continuum – geared towards efficient materials design for electronics, sensors and energy. We are interested in the development of innovative modeling approaches integrated together with processing and characterization. Atomistic, molecular (e.g., molecular dynamics) as well as continuum mechanics modeling approaches are of interest for developing multiscale computational tools for tailored materials design of multiple constituents and its nanostructured interfaces. Creative material metrology in conjunction of the materials modeling is also of interest.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.06.B5510: Durability and Damage Tolerance of Polymer Matrix Composites

Schoeppner, G.

(937) 255-9072

Research focus is on the development of process-modeling and material behavior tools for structural polymer matrix composites to support the development of an Integrated Computational Materials Engineering approach for material design. The overall objective is the development of fundamental processing-structure-property relationships for composites through integration of analytical, numerical and experimental tools. Emphasis is placed on models that describe the fundamental behavior of the material including: (1) failure initiation and propagation that including micro and global buckling for compression loading of composites; (2) spectrum loading fatigue crack initiation and growth in composites; (3) linking processing and mechanical performance models for aerospace grade structural composites; and (4) development of analytical/numerical and testing methods for characterizing and modeling the environmental degradation of polymer matrix composites. Interest includes continuously reinforced composites manufactured from uni-directional layers as well as textile fiber morphologies (weaves and braids). Excellent facilities are available including polymer composite processing lab, thermal analysis lab, x-ray tomography, electro-optics lab and mechanical testing lab.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.06.B5511: Constitutive Modeling of Time-Dependent Behaviors in Composite Materials

Hall, R.B.

(937) 255-9097

Needs exist to characterize the thermomechanical behaviors of composite materials for applications involving time-dependent behaviors under the influences of e.g. high temperatures, intrusion of moisture, loss and modification of material properties due to oxidation and hydolysis. The morphing structures area is a recent opportunity involving the potential large deformations of aersopace stuctural materials under influence of various forms of material rearrangement, and may also involve reacting material systems. Constitutve models are sought that are thermodynamically consistent and are eventually suitable for finite element structural modeling.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.06.B6610: Nanoscale Energy Transport Interfaces

Voevodin, A.A.

(937) 255-4651

This opportunity focuses on fundamental research of charge and phonon transport in nanostructured materials and interfaces. Thin films, coatings, nanostructured surfaces, and surface modification approaches are the prime interest. The overall objective is to establish basic science knowledge to understand and control complex physical properties for next generation of electronics and thermal interfaces, including electrical and thermal energy transport, electron/phonon coupling, and ballistic thermal transport. Charge transport as well as electronic and phononic thermal transport in two dimensional and other nanostructured materials are considered. Surface analytical studies in combination with in-situ and ex-situ surface investigations by various material, electrical mobility, charge carrier density, and thermal property characterization methods should be applied to uncover basic mechanisms occurring on thermal and electronic interfaces. Research in conceptually new material solutions (e.g., adaptive charge and phonon transport interfaces, nanostructured low dimensional materials, and molecular level engineered interfaces) are of special interest. These efforts can be connected to experimental investigations in thin film and coating material synthesis using novel technologies, such as hybrid plasma assisted deposition of nanostructured materials. Basic process-structure-property correlations for new synthesis technologies need to be uncovered. The AFRL Materials Laboratory provides a spectrum of experimental capabilities for this research opportunity to cover most of the anticipated research needs.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B0140: Growth and Characterization of Nonlinear Optical Materials

Zelmon, D.E.

(937) 255-9867

We conduct research on nonlinear optical materials and materials processing for a variety of applications including integrated optics and frequency conversion. Activities include optical waveguide fabrication, study of optical phenomena such as the photorefractive and electro-optic effect, and theoretical modeling. Recent work has focused on the development of materials for high power fiber lasers including polycrystalline YAG and rare earth sesquioxides. A wide variety of physical, chemical, and optical characterization facilities exist including interferometry, ellipsometry, two-wave mixing, waveguide propagation measurements, absorption spectroscopy, Auger spectroscopy, x-ray diffraction, photoluminescence, and wavelength conversion measurements.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B0141: Synthesis of Organometallic Dyes for Nonlinear Optics Applications

Cooper, T.M.

(937) 255-9620

We are investigating the synthesis and characterization of dyes and polymers for nonlinear optics applications. The systems we are studying include porphyrins, phethalocyanines, platinum acetylides, other organometallic chromophores and gold nanoparticle-chromophore hybrids. We investigate the fabrication and properties of polymer composites and molecular glasses containing these materials. We also perform investigation of excited state behavior, including flash photolysis, ultrafast transient absorption spectroscopy and emission spectroscopy. Researchers with experience in chemical synthesis, organometallic chemistry and polymer engineering areencouraged to apply.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B0154: Optical Properties of Semiconductors

Brown, G.J.

(937) 255-3808 x3238

This research focuses on the infrared (IR) absorption and optical properties of nanoscale semiconductor heterostructures such as quantum dots, quantum wires and superlattices.. Materials under investigation include InAs quantum dots,and superlattices based on III–V compounds, such as InAs/GaInSb and InAs/InAsSb.

The epitaxial heterostructures are grown using molecular beam epitaxy. Designing and testing the unique properties of these nanoengineered materials is a key focus of the program. Therefore, theoretical work on modeling the properties of new materials is included under this topic. Of interest is improved understanding of optimizing the optical absorption processes, tailoring the absorption bands, and enhancing electrical charge transport of photoexcitied carriers. Understanding the interfaces between the various materials in the heterostructure plays an important role in the materials development process. Typically the materials under study are for infrared detection.

Expertise in optical characterization techniques such as photoluminescence, UV/Vis/IR absorption, or photoconductivity is relevant to testing the optical properties of the materials. There is a Cary 5000 UV/Vis/near IR spectrometer, a Varian FTS 6000 mid-IR to VLWIR spectrometer, and a Bruker FTIR photoluminescence spectrometer in-house. All of these systems are capable of measurements at cryogenic temperatures. There are many other facilities in-house that can also be utilized in the study of these materials, such as HRTEM, HRXRD, SEM, AFM, STM, XPS, SIMS, Auger spectroscopy, and Hall Transport measurements.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B3757: Dynamic Optical Materials using Soft Matter Motifs

Bunning, T.J.

(937) 255-9617

We study the structure/property relationships of a variety of materials systems, which are broadly applicable to linear and nonlinear optical materials. Emphasis is placed on utilizing the electro-optical properties of liquid crystals for a wide variety of applications, including the development of switchable diffractive optical elements using controlled phase separation of polymer/liquid crystal composites. We are examining the fundamental polymer and liquid crystal physics, which govern the morphology and subsequent electro-optical behavior of this unique class of composites. Our interests include understanding the complex balance between phase separation, diffusion, and polymerization kinetics, and how these change as a function of the starting materials and conditions. Other liquid crystal interests include new twisted liquid crystal motifs, cholesteric and cholesteric polymer films, and novel combinations of liquid crystal and polymer structures. Current interests include photo and electro-optic mixtures of cholesteric liquid crystal/polymer mixtures, polymer photochemistry, physics of polymer structures grown from surfaces, anisotropic polymerization methodologies, polymerization strategies/designs within structured media, and novel photonic thin films fabricated using plasma enhanced chemical vapor deposition techniques.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B4280: Synthesis and Characterization of Organic NLO Materials

Urbas, A.M.

(937) 255-9713

Metamaterials redefine the fundamental properties of systems by creating artificial, meso-scale meta-atoms which dictate the system response to external fields. When assembled into complex, structured materials, these meta-atoms and their mutual interactions can yield effective property sets not found in conventional materials and response tailored to specific application needs. The concept of defining the material properties with structure extends beyond electromagnetics to mechanical and thermal characteristics as well. Significant interest lies in the development of novel metamaterials structures and designs for electromagnetic and mechanical systems that possess properties optimized for selected applications. Key challenges are to develop capabilities to fully analyze the properties of these systems computationally and experimentally, to extract truly representative effective properties, and to understand the effectiveness of materials in an applications context. In the midst of this rapidly evolving field, AFRL is conducting a program to determine the utility of metamaterials in applications, evaluate their technological relevance and identify areas where focused efforts can enable rapid technological insertion. Of special interest is the development of new optical materials through the use of nanophotonic and plasmonic metamaterials. The creation of new nonlinear effects, optical properties and devices, as well as, the enhancement of existing materials properties for optical technologies are possible through the application of metamateirals design principles. We are studying the creation of optical antenna arrays through self-assembly, two photon lithography and holographic patterning to selectively concentrate and manipulate light. Electromagnetic design and optimization are areas of significant interest for developing efficient structures for optical applications. Near field scanning microscopy, optical characterization, nonlinear measurements and ultra-fast pulse measurement techniques are used to determine the properties of the fabricated systems and compare the performance to modeled behavior. Areas of new study include the incorporation of active and tunable materials to generate dynamic response from plasmonic arrays.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B4282: Infrared Optical Material Development

Guha, S.

(937) 255-6636 x3022

Strong third order nonlinear optical performance is demonstrated by many materials in the infrared (IR), including narrow and mid-bandgap semiconductors in the bulk form, as well as thin-film coatings of various oxides. Our overall goal is to understand and optimize the nonlinear optical properties of these materials through theoretical and experimental studies involving IR laser beams in different wavelength and pulse duration regimes. Currently, the IR materials project includes the development of materials, versatile characterization of materials properties, and detailed understanding of materials properties through modeling. The materials being developed include novel semiconductor alloys in crystalline or glassy forms and thermochromic oxide thin films. A variety of laser systems are used to characterize the materials at cryogenic and ambient temperatures. The modeling effort includes semiconductor material modeling, as well as laser beam propagation modeling with the eventual goal of combining the two efforts to obtain complete information about the laser-material interaction. Laser beam propagation modeling presents challenges for fast optical systems-especially when aberration of lenses have to be taken into account-and for propagation through multiple linear and nonlinear optical elements.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B5104: Materials for Integrated Electro-Optic Circuits

Grote, J.G.

(937) 255-9776

Our research focuses on the development of bio-organic materials and fabrication processes for high-speed, low operating power, high efficiency, small size organic-based integrated electronic and photonic devices, including organic field effect transistors (OFETs), organic light emitting diodes (OLEDs, organic light emitting diodes (OLETs), organic electro-optic (EO) modulators and organic photovoltaics (OPVs). In-house research involves investigation of bio-organic based semiconductor and gate dielectric materials for FETs and OLETs, blocking, transport and active layers for OLETs, OLEDs and OPVs and cladding and active layers for EO modulators. Work includes (1) materials processing; (2) electromagnetic, optical and nonlinear characterization of materials; (3) new fabrication methods and processes; (4) computer modeling and simulation; and (5) integration, packaging, and manufacturing processes. Materials of interest include deoxyribonucleic acid (DNA) and silk. Close collaboration with other Air Force research directorates is a high priority.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B5456: Surface Phenomena in the Formation of Epitaxial Quantum Structures

Eyink, K.G.

(937) 255-5710

This research focuses on the modification of quantum III-V semiconductor dot structures obtained during the molecular beam epitaxial growth through nano-patterning of surfaces and self assembly. Typically, growth of III-V semiconductor dots are formed through the self-assembly process, which is rooted in the strain driven nucleation and growth of the three-dimensional epitaxial crystals. The goal of this research is to determine the extent to which nano-patterning can be used to control the location and size distribution of quantum dots(QDs) and wires and also to the extent that dissimilar materials can be integrated using strain. We are currently focusing on the ability of strain driven epitaxy to align semi-metallic ErAsSb nanoparticles (NP) with InGaAs QDs. In this work, we employ both in situ sensors (such as spectroscopic ellipsometry, desorption mass spectrometry, and reflection high energy diffraction) and ex situ characterization (such as variable angle spectroscopic ellipsometry, AFM, STM, x-ray reflectivity and in-plane x-ray diffraction). An intermediate goal is to determine the growth conditions to produce vertically stacked layers of ErAs NP to InAs QDs. These layers are being formed to enhance detector, emitter, and other electronic and optical structures relevant to DOD applications.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B5471: Development and Characterization of Photorefractive Materials

Evans, D.R.

(937) 656-6670

Photorefractive materials possess high nonlinearities and have been extensively studied for applications in all-optical devices, where the transfer of energy from one beam to another (beam coupling) through the establishment of a refractive index grating is the dominant process. The two primary material classes that we are investigating for beam coupling (energy transfer) applications are: organic-inorganic photorefractive hybrids and inorganic photorefractive crystals. Additional studies including ferroelectric nanoparticles and photorefractive thin films are being conducted, as they benefit the hybrid approach by increasing the optical gain and reducing the absorption loss.

We are interested in developing and understanding the physics of bulk crystals, polymers, thin films, and ferroelectric nanoparticles for photorefractive beam coupling in the visible, near-infrared, and infrared spectral regions. Because the photovoltaic effect can strongly influence the formation of gratings in some materials, we are also interested in the electrical properties of photorefractive materials.

References":

D. R. Evans, et al., Opt. Lett., 36, 454 (2011).

S. A. Basun, et al., Phys. Rev. B, 84, 024105 (2011).

G. Cook, et al., J. Appl. Phys., 108, 064309 (2010).

G. Cook, et al., Opt. Exp., 18, 17339 (2010).

G. Cook, et al., Opt. Exp., 16, 4015 (2008).

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B5509: Theory and Computation for the Design of Molecular-to-Bio/Nanomaterials

Pachter, R.

(937) 255-9689

We are exploring the development of materials for applications in photonics, electronics and sensing, ranging from molecules in the condensed phase, to nano-scale structures. Our research focuses on developing and applying fundamental theoretical and computational chemistry and materials science approaches, including multiscale modeling. The goal is to explain observed phenomena and predict key parameters that determine materials behavior, also in a device setting, to enhance the capability for "real materials" design and atomic-scale control. Examples of theory and computation comprise, but are not limited to, optical excitations in finite and extended material systems, including nonlinear optical applications, such as multi-photon processes, and nano-plasmonics; concepts in molecular and nano/bioelectronics; biocatalysis; and relevant interactions at (bio)organic-inorganic interfaces, all of which are analyzed in comparison with experimental measurements. Access is available to state-of-the-art high performance computing and to experimental facilities for characterizing materials and devices.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.07.B6434: Materials Behavior in Operating Electronic Devices

Dorsey, D.L.

(937) 528-8739

The performance and lifetime of electronic devices are both critically dependent on the behavior of the constituent materials during device operation. High electric fields, high stress/strain fields, high current densities, high temperatures and high thermal gradients may all drive material changes that can lead to degradation in device performance and ultimately device failure. Physical mechanisms that contribute to this include diffusion of electrically active impurities, generation of carrier traps, dislocation generation and propagation, hot electron effects, and interfacial instabilities. We focus on developing models of materials behavior in operating electronic devices, and using these to predict and optimize electronic device performance and lifetime. Opportunities exist for theory and model development, as well as for characterization of materials in operating, degraded, and failed devices using microRaman and scanning probe microscopy.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.09.B0146: Fracture Mechanics and Fatigue of Materials

Larsen, J.M.

(937) 255-1357

Within a framework on Integrated Computational Materials Science and Engineering, our research involves developing physics/mechanistically based models for predicting and optimizing the service lives of advanced turbine-engine and aircraft materials. Our primary focus is on high-temperature titanium alloys and Ni-base superalloys under simulated operating conditions using an advanced physically based fatigue and fracture-mechanics approach. Specific topics of interest include (1) modeling the influence of temperature, frequency, mean stress, and load history on fatigue initiation and crack growth including cumulative-damage modeling applied to spectrum loading; (2) environmental effects; (3) small-crack-growth behavior; (4) threshold crack-growth behavior; and (5) crack growth at notches. Interest centers on conducting advanced micromechanical experiments and developing models of the relationships between microstructure and life-limiting properties, emphasizing scientifically-based reduction in uncertainty, probabilistic analysis, and Bayesian methods. Excellent laboratory facilities are available for multi-scale experiments and computations.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.09.B0150: Processing Science

Semiatin, S.L.

(937) 255-1345

Research is conducted to develop material-behavior and process-modeling tools in order to exploit the full potential of conventional metals and emerging new materials such as intermetallics, ceramics, and composites using advanced ingot metallurgy, powder, vapor, and solidification-process technology. Specifically, we develop and validate advanced capabilities for relating the fundamental laws that govern processes to the evolution of microstructure/texture and the resulting mechanical properties. We emphasize the following: (1) mathematical analyses of unit processes such as extrusion, forging, rolling, and casting; (2) development of numerical models for process simulation on computers; (3) material modeling to understand the material behavior response to process conditions (e.g., phase transformation, texture evolution, fracture behavior); (4) development of constitutive equations for use in numerical models; (5) physical modeling for verification of analytical models; (6) interface-property modeling to represent friction and heat transfer as a function of process variables; (7) evolution of controlled microstructures during processing; and (8) development of novel processes.

Special emphasis is also placed on the development of advanced models, such as those based on crystal plasticity, cellular automata, Monte-Carlo, and phase-field techniques, for the prediction of microstructure and texture evolution during processing.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.09.B0153: Modeling Structural Alloys for Aerospace Applications

Woodward, C.F.

(937) 255-9816

This research focuses on developing and applying modeling and simulation methods to explore broad aspects of metal alloy development. Target materials include, but are not limited to, high temperature structural materials such as Ni-based superalloys, refractory metal intermetallics and Ti-Al alloys. Current areas of interest include modeling plasticity at the atomic and micron scales using electronic structure, atomistic and dislocation dynamics methods. Research in this area includes size scale, chemical, ordering, solution, and precipitate effects. Also, free energy models, based on first principles methods, are used to predict phase stability and the nature and evolution of defects in these materials. This includes properties of both the liquid and solid phases and the microstructural evolution of complex metal alloys. Significant computational resources are available through the High Performance Computing Modernization Office to perform large scale calculations, analysis and visualization. Research is closely integrated with the group's 3-d characterization and micro-scale plasticity experimental techniques and the AFRL/RX characterization facility.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.09.B5769: Ceramics for High-Temperature Structural Applications

Hay, R.

(937) 255-9825

Numerous basic issues remain to be addressed to enable the development of a full range of high-performance ceramics and ceramic-matrix composites for Air Force and space applications. These issues encompass basic design issues, compatible chemistries, enabling processes, and new constituents. These will need to be pursued through several iterations at successively higher temperatures in order to enable durable, tough high-temperature structural materials for the broad range of applications envisioned. Over the past fifteen years, research has focused on the development and characterization of viable oxide-based fiber coatings for controlling debonding and establishing sufficient understanding of processing/structure/property relationships for composite system design. Current research focuses on investigating higher temperature oxide and non-oxide constituents for enhanced durability, continuing development for fiber coating and interface control science and technology, developing processes for dense matrix composites for both oxide and monoxide fibers, investigating the stability of oxides and nonoxides in aggressive environments, and developing design methodologies for durable composites. Quantitative microstructure characterization followed by physics-based relationships between microstructure metrics and processing and/or mechanical properties will be used extensively for modeling material system behavior.

Reference:

Kerans RJ, et al: Journal of the American Ceramic Society 85(11): 2599, 2002

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.10.B4301: Biomimetics: Bionanotechnology, Biosensors and Biomaterials

Naik, R.

(937) 255-9717

The interface between biology, chemistry, and materials science has motivated biomimetic approaches to fabricate novel materials and devices for optical, electronic, magnetic and sensing applications. The diverse structures and function of biomaterials offer many exciting opportunities for creating multifunctional materials. For example, combining biomolecules with abiotic components can result in the development of novel electronic and sensing platforms. We are interested in understanding the interactions between biotic and abiotic materials, bio-functionalization approaches to creating novel structures and sensors, understanding structure-property-functional relationships of biomaterials, development of deposition techniques for biomaterials, interfacing biomaterials with electronic materials, and integrating 3-D printing techniques with biomaterials/bioinks. These fundamental studies are the foundation of many applied technology efforts for aerospace and other application areas. We use biochemical and molecular biology tools, atomic force microscopy, deposition tools, standard bulk and surface spectroscopy, modeling, processing, and synthesis in our efforts.

Keywords: Bionanotechnology; Biomimetics; Biomaterials; Sensors: Bioelectronics, 3-D printing; Flexible Devices

Eligibility: Open to U.S. citizens and permanent residents

References:

1. Slocik J. M. Crouse C. A., Spowart J. E. & Naik R. R. (2013) Biologically Tunable Reactivity of Energetic Materials Using Protein Cages. Nano Lett 13, 2535-2540

2. Kim S. S., Hisey C. L., Kuang Z., Comfort D. A., Farmer B. L. & Naik R. R. (2013) The Effect of single wall carbon nanotube metallicity on genomic DNA-mediated chirality enrichment. Nanoscale 5, 4931-36

3. Dickerson M. B., Lyon W., Gruner W. E., Mirau P. A., Jespersen M. L., Fang Y., Sandhage K. H. & Naik R. R. (2013) Unlocking the Latent Antimicrobial Potential of Biomimetically Synthesized Inorganic Materials. Adv. Funct. Matls. DOI: 10.1002/adfm.201202851

4. Kuang Z., Kim S. N., Crookes-Goodson W. J., Farmer B. L. & Naik R. R. (2010) Biomimetic Chemosensor: Designing Peptide Recognition Elements for Surface Functionalization of Carbon Nanotube Field Effect Transistors. ACS Nano. 4, 452-458

5. Slocik, J. M. & Naik, R. R. (2010) Probing peptide-nanomaterial interactions. Chem Soc. Rev. 39, 3454 – 3463

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.10.B4959: Alkali-Free Bulk Glasses and Laser Sintering of Ceramic Fibers

Goldstein, J.T.

(937) 255-9785

In-house experimental research is currently being conducted in the following two areas:

1. Synthesis and characterization of bulk alkali-free (AF) oxide glasses.

2. Laser sintering of ceramic fibers (similar to Laser Heated Pedestal Growth, or LHPG).

The bulk glasses and ceramic fibers are intended for applications in the areas of capacitive energy storage and high-power fiber lasers, respectively. Opportunities exist for participation by individuals with relevant experience in bulk glass synthesis and characterization, laser system design, or processing of ceramics. Besides advancing the technologies themselves, basic structure-property relationships in Alkali-Free glasses as well as basic physical mechanisms of grain growth under the influence of extreme electric fields and extreme thermal temporal and spatial gradients are also being explored. Experience in theoretical modeling of such physical phenomena would also be very welcome. All facilities and equipment necessary for conducting the experiments are present in-house.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.11.B4960: Modeling of the Corrosion Processes

Jata, K.

(937) 255-1351

Opportunities exist to conduct fundamental research in the area of modeling of corrosion processes with emphasis on both physics-based as well as data-driven modeling. Physics based models will incorporate metallurgical microstructure-- nano to grain size--scales, nano-scale corrosion processes and scale-up to meso- and macro- scale corrosion phenomenon, imposition of loads-static, sustained and or cyclic and their effects on corrosion. Alloys of interest are aluminum-lithium, titanium and nickel alloys and modeling of corrosion performance can include coatings failure. Data driven models shall consist of Bayesian, and spread-sheet modeling approaches to corrosion. Hybrid modeling approaches are of much interest. The current corrosion team at AFRL Materials and Manufacturing Directorate is actively involved in galvanic corrosion modeling, corrosion fatigue of complex structural coupons and probabilistic modeling of coating failure.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.12.B1214: Computer Simulations for Design of Improved Aerospace Materials

Berry, R.

(937) 255-2467

Research relates to current and prospective interests in design of improved materials for aerospace applications. Calculations include electronic structure theory, molecular dynamics, chemical kinetics modeling, and density functional theory calculations under three-dimensional periodic boundary conditions. Properties of interest include computation of physical characteristics (e.g., glass transition/melting temperature, density), elucidation of reaction pathways and determination of reaction mechanisms, prediction of interfacial phenomenon, and calculation of mechanical properties. Projects of interest are described below:

(1) Molecular dynamics simulation of the binding of small model DNA fragments to surfactants in various solvents. We are interested in the nature and free-energy of binding. These materials are being investigated for their potential application in photonics and molecular electronics.

(2) Atomistic simulation of peptides that bind to surfaces (inorganic and graphitic) as identified by bio-panning experiments. Estimate binding constants, conformational changes on adsorption, and the mechanism of binding and compare with experimental data. Analyze results as a function of peptide sequence, surface coverage, pH, surface structure, and roughness. Investigate bio-mineralization in order to determine the thermodynamic stability of various morphologies and particle shapes.

(3) Prediction of the physical and transport properties of model ionic corona nanoparticles as a function of composition. Compare the results of the simulations to NMR experiments and direct measurements.

(4) Molecular dynamics simulations to evaluate the modulus, strength, and fracture toughness of polymers and composites. This project is in conjunction with ongoing experimental measurements and micromechanics calculations.

Keywords:

Nanoparticle; Bio-inspired; Bio-panning; Bio-mineralization; Force field; Ab initio; Molecular dynamics; Density functional theory; Mechanical properties of polymer-composites; Mechanical properties of thermoset polymers

Eligibility

Citizenship: Open to U.S. citizens and permanent residents

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.13.B1009: Flexible Materials & Devices for Structural Power

Leever, B.

(937) 255-9141

Multifunctional materials offer the potential to address size, weight, and power considerations while expanding functionality in a wide range of Air Force applications. Our research focuses on integrating energy harvesting and/or energy storage capabilities into structural materials such as polymers or composites. This approach could enable concepts such as solar energy harvesting by an organic photovoltaic film sprayed onto the wings of an aircraft or energy storage by a battery printed onto a wearable device. Research efforts focus primarily on innovative materials, architectures, and processes for thin film or conformal solar cells and batteries as well as for nanocomposite dielectric capacitors.

Our research interests include several fundamental topics in this field. First, we work toward understanding the role of interfaces and morphology in these devices with a goal of tailoring device performance. Second, we employ a wide range of characterization tools, with an emphasis on photophysical analysis, to determine the fundamental physical phenomena in these materials and how they impact device operation. Third, we are interested in developing and improving processes that allow for conformal, thin-film deposition of solid state devices across a spectrum of length scales, form factors, and substrates. In all three of these areas we use a variety of analytical techniques including x-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, x-ray diffraction, x-ray reflectivity, atomic force microscopy, electron microscopy, time-of-flight mobility, and photoinduced absorption among other techniques. In addition to experimental investigation, we are also interested in applying computational and modeling methods to accelerate developmental efforts. These ICMSE approaches are expected to be particularly fruitful in predicting materials properties and behavior at interfaces.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.13.B7100: Hierarchical Reinforced Polymer Composites

Baur, J.

(937) 255-9649

We are interested in understanding and manipulating the interfaces of structural fibers with nanomaterials to tailor the mechanical, electrical, and piezoresistive properties in order to provide flow-sensing artificial hair sensors and a means to manipulate the interfacial properties of multifunctional polymer matrix composites. This effort involves synthesis of high aspect carbon and inorganic nanotubes/nanowires upon structural fibers; characterization of their structures via TEM, SEM, and spectroscopy; and evaluation of electrical, mechanical, and their coupling properties at multiple scales.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.13.B7101: Adaptive (Morphing) Composite Materials

Baur, J.

(937) 255-9649

Morphing materials are those state-changing materials systems that are able to adaptive to achieve multiple, time-variant properties. Mechano-adaptive composites provide multi-mission capability for air, space and/or land assets by modulating mechanical properties such as modulus to allow for significant structural reconfiguration while maintaining sufficient structural properties at the initial and final states to be useful. Designs could involve a reinforced state-changing polymer (such as shape memory polymers), novel reinforcement architectures (weaves, arrays, truss-structures, bio-like joints, etc.), and embedded triggering and actuation systems all contained in a compact and lightweight form. Ultimately, structural systems which can autonomically respond to an external stimulus are envisioned for enhanced survivability and optimization of air flow.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.13.B7103: Nucleation and Growth of Carbon Nanotubes

Maruyama, B.

(937) 255-3920

Carbon nanotubes have been studied extensively beginning in the early 1990's. Their unparalleled properties make them attractive for application in composites, electronic devices, sensors, etc. However, production of nanotubes remains inefficient and expensive, and the as-produced purity is typically less than desired. Improvements in production yield, catalyst efficiency, purity and type selectivity will enhance the viability of these materials. A fundamental understanding of the mechanisms by which nanotubes nucleate and grow is pursued in order to achieve such improvements by in-situ characterization of nucleation and growth.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.14.B0111: Multiferroic Heterostructure Materials

Brown, G.J.

(937) 255-3808 x3238

This research focuses on the characterization of materials for enhancing the magneto-electric (ME) coupling in multiferroic heterostructures. High resistivity (low loss) ferrimagnets are used in a wide range of passive microwave components such as isolators, circulators, phase shifters, filters, resonators and miniature antennas operating at a wide range of frequencies (1-100 GHz). If paired with a piezoelectric material, changes in the electric field of the piezoelectric can be used to tune the magnetic properties of the ferrimagnet which opens up a whole host of tunable microwave passive components. Oxide heterostructures which tailor the permeability and permittivity of the resulting layered material, and oxide/hexaferrite layered materials for tunable devices are both of interest to this program. This project would primarily focus on the characterization of the ME coupling strength, the permittivity, the permeability and the ferromagnetic resonances in the fabricated materials. It could also include modeling of the materials to enhance these properties. We have specialized microwave characterization facilities such as field sweeping and frequency sweeping measurements of the ferromagnetic resonance, as well as the capability for growth of oxide materials via pulsed laser deposition. In addition, there are many other facilities in-house that can also be utilized in the study of these materials, such as HRTEM, HRXRD, SEM, AFM, PFM, XPS, MFM SIMS, Auger spectroscopy, dielectric measurements and Hall Transport measurements.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.14.B0823: Germanium-Enabled Silicon Photonics

Hopkins, F.

(937) 255-9890

Electronic circuits alone cannot fully meet future requirements for speed, size, and weight of many sensor systems, such as digital radar technology and as a result, interest in integrated photonic circuits (IPCs) and the hybridization of electronics with photonics is growing. However, many IPC components such as photodetectors are not presently ideal, but germanium has many advantages to enable higher performance designs that can be better incorporated into an IPC. For example, Ge photodetectors offer an enormous responsivity to laser wavelengths near 1.55µm at high frequencies to 40GHz, and they can be easily fabricated as part of a planar silicon processing schedule. At the same time, germanium has enormous potential for enabling 1.55 micron lasers on silicon and for enhancing the performance of silicon modulators. We are presently investigating new material structures for various photonic components of IPCs.

Keywords:

Integrated Photonics, Germanium, Photodetector, Optical Modulator, Phototransistor

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.14.B0916: Optoelectronics and Electronics Based on Carbon and 2D Materials

Mou, S.

(937) 255-9523

Carbon materials are unique in terms of the rich variety of allotropes (e.g., graphene, carbon nanotubes, fullerenes) in the material family. From the perspectives of optoelectronics and electronics, carbon materials have great potentials (e.g., high mobility, low cost, and large area) but have yet made substantial impacts due to various reasons. Therefore, in this topic, we will look into novel ways of utilizing carbon materials for optoelectronic and electronic applications such as infrared sensing, RF electronics, and solar energy harvest. One example is that we will apply a novel physical concept, namely plasmonics, on graphene and carbon nanotubes to investigate its potential in infrared sensing. Another route is to carefully design carbon heterostructures to tailor the optical absorption by mixing various carbon allotropes. On the other hand, materials such as transition metal dichalcogenides (e.g., MoS2, WSe2, etc.) and boron nitride have recently found research interests in their two dimensional (2D) form. They form a variety of allotropes similar to carbon and are attractive in applications of optoelectronics and electronics. It is interesting to study the heterostructures formed with various 2D materials and their allotropes. The goal of this project is to generate innovative concepts on carbon based optoelectronics and electronics for the interests of AF and DoD.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.14.B1018: Conformal and integrated electromagnetic structures for flexible and reconfigurable applications

Tabor, C.

(937) 255-9899

There is a growing requirement to develop new classes of materials and paradigms to address the need for conformal and integrated features that are responsive to RF frequencies. Many of these approaches are related to the field of metamaterials and plasmonics, where the behaviors of metallic features have highly correlated structure/property relationships. Exploring these relationships through modeling, fabrication, characterization, and processing developments is an area where extensive research is being conducted.

Efforts focus on developing new paradigms utilizing metallic and semi-metallic structures and their interactions with flexible substrates. An iterative approach utilizing simulation and experimentation will be used to address highly multi-discipline problem sets that include fields such as chemistry, physics, material science, and engineering. The goal is to develop materials and processing techniques to create integrated RF resonant structures such as reconfigurable antenna front ends and embedded flexible sensors that will generate novel capabilities.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.14.B1101: Microstructure Quantification and Damage Modeling of High Temperature Continuous Fiber Reinforced Ceramic Matrix Composites

Przybyla, C.

(937) 255-9396

Research focus is the development of Integrated Computational Materials Engineering (ICME) tools for the development and design of continuous fiber reinforced ceramic matrix composites (CMCs). Specifically, current needs center on development of processing-structure-property relationships for optimization of CMCs for demanding high temperature applications. CMCs are highly desirable as an alternative to high temperature metals due to higher operable temperature regimes and lower density. The variability of the damage response due to fatigue or creep at high temperature in CMCs is dependent on variability in the predominate microstructural attributes such as fiber spacing, fiber coating thickness, distributed secondary matrix phases and distributed porosity.

Primary research trusts include:

1.) Process models are needed that can predict variability in key microstructure attributes such as porosity or coating thickness distribution. Processes such as chemical vapor infiltration (CVI), chemical vapor deposition (CVD) or melt infiltration (MI) are all employed to produce CMCs, coat fibers or densify matrices. Each process has inherent strengths and weaknesses and can lead to defect populations that directly affect response variability. Models that link process and process parameters to distributed attributes in the microstructure are desired.

2.) Tools necessary to quantify microstructure variability using optical, electron, or x-ray based imaging techniques are required. Post processing of microstructure data using segmentation and feature extraction can be quite time intensive and requires significant human intervention. It is desired to employ state-of-the-art computer vision and develop automated algorithms based to detect and quantify the primary features of interest (e.g., fibers, pores, fiber coatings). Once the key attributes of interested are characterized, algorithms to construct digital microstructure models representative of the characterized materials are needed for property prediction.

3.) To predict damage response of CMCs at high temperature better physics based models are needed to capture the interplay between environmental degradation and mechanical damage. Oxidation of CMCs can be significant and better models and modeling strategies are needed to predict the rates of reaction and oxidation kinetics, particularly when cracking of the matrix under mechanical loading provides pathways for transport of oxidizing species. An overall framework is desired that can be used to predict variability in response based on the variability of the key microstructural attributes that dictate the response.

Research facility provides many opportunities for specialized high temperature testing and significant computing resources to aid in any project.

AFRL/RX WRIGHT PATTERSON AF BASE, OHIO

SF.25.14.B1117: Uncertainty Quantification of Geometric Measurements for the Assessment of Manufacturing Variability

Sizek, H.

(937) 904-4589

The Air Force Research Laboratory is conducting research to quantify the impact of geometric variability on system and subsystem performance. Realistic distributions that describe the geometric variations found in manufactured components are required to serve as inputs to performance models. The quantification of this dimensional variation typically requires high-quantity noncontact data acquisition, data analysis techniques, and a sufficient understanding of the systematic and random errors involved.

The overall objective of this research is to quantify measurement process uncertainty so that high-resolution (laser scanning, structured light, etc.) measurement repeatability and reproducibility (gauge R&R) can be distinguished from the intrinsic geometric variation of manufactured components. An emphasis is placed on conducting a phased approach to address one data acquisition system on simple geometry, followed by more complex geometries produced by multiple manufacturing processes. The Materials and Manufacturing Directorate's resources include: access to laser scanning hardware and software, access to high-quantity scanned data from various on-going AF ManTech programs, and potential access to a National Institute of Standards and Technology (NIST) effort focused on noncontact equipment correlation via repeated scanning of test artifacts. In addition, representative test articles will be provided to aid in correlating measurement process uncertainty research to system performance modeling.

References:

Calkins, J., (2002), "Quantifying Coordinate Uncertainty Fields in Couples Spatial Measurement Systems", Doctoral Thesis Virginia Polytechnic Institute and State University.

Martinez, S., Cuesta, E., Barreiro, J., and Alvarez, B., (2010), "Analysis of Laser Scanning and Strategies for Dimensional and Geometrical Control", The International Joutnal of Advanced Manufacturing Technology, 46(5-8), pp. 621-629.

Feng, H., Liu, Y., and Xi, F., (2001), "Analysis of Digitizing Errors of a Laser Scanning System", Precision Engineering, 25(3), pp. 185-191.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.35.13.B0833: Reactive Flow Modeling

Dorgan, R.J.

(850) 882-3124

The survivability of a penetrator energetic payload, i.e. the ability of an energetic payload to function as intended after a penetration event, is essential. Additionally, these systems require that the payload be insensitive to insult from external sources prior to delivery. To satisfy these two requirements, there is a need for accurate and robust numerical reactive material models that predict both the mechanical and initial energetic behavior. Knowledge of the thermodynamics leading to chemical reaction is required in order to link the state of the material under load to initial chemical kinetics of the explosive. Historically, ignition models have been based on pressure and duration, and it is believed that more advanced approaches such as temperature based and entropy based modeling are even more predictive. This research topic seeks to develop physically relevant reactive flow models for energetic materials of Air Force interest implemented in relevant hydrocodes. A significant part of this effort is to develop experimental techniques through numerical modeling that will demonstrate phenomena that these empirical models cannot predict. This will require a significant research effort in order to develop a reactive flow model that considers the details of chemical composition evolution during the reaction process.

Keywords: Reactive, numerical, simulation, hydrocode, detonation, shock

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.01.B5483: Efficient Processing of Optimally Sampled 2-D and 3-D Imagery

Rummelt, N.I.

(850) 883-0886

The hexagonal grid and the body-centered cubic (BCC) lattice are the optimal sampling lattices for isotropically band-limited 2-D and 3-D signals, respectively. These lattices provide significant improvements in sampling efficiency over traditional rectangular sampling but have not been commonly used due to inefficiencies related to their non-Cartesian nature. A recent advance in addressing such lattices promises to overcome the inefficiencies and allow for the use of these optimal sampling approaches for common image processing applications. Research is being conducted that aims to take advantage of the improved sampling efficiency of these lattices to provide significant improvements in various areas of signal processing. Research opportunities exist in the development of fundamental techniques in processing optimally sampled imagery that lead to demonstrable improvements over current state-of-the-art approaches.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.01.B5815: Integrated Navigation Techniques for Precision Guidance, Navigation, and Control

Miller, M.M.

(850) 882-4033

Our goal is to research and develop the latest technologies to provide Precision Navigation, Attitude, and Time (PNAT) for military weapon systems operating in any environment at any time. PNAT is the cornerstone in providing weapon systems with the assured reference technologies required for precision attack, network enabled ISR sensing, and warfare anywhere at any time. Research includes investigating new inertial sensors and their integration with secondary sensors and seekers (preferably passive) that provide precision measurement updates. Several potential secondary sensors include a software GPS receiver, which is resistive to jamming signals; optical sensors using passive image data; LIDAR sensors using ranging data; RF-based sensors such as Ultra-Wide Band, software based receivers capable of receiving and processing any viable Signals of Opportunity; and biological-based navigation using natural signals such as the Earth's magnetic field, polarized light, olfaction, and echo-location.

Current in-house research focuses on the PNAT described above for developing the sensors, seekers, and techniques for integrating navigation technologies for precision Guidance, Navigation, and Control. The goal is to develop autonomous vehicles that can operate in difficult environments where GPS may not be available. A critical piece of this research effort is to determine the optimal method for integrating various navigational aiding sensor data into a precision weapon system.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.02.B5463: Energetic Nanocluster Thin Films

Lindsay, C.M.

(850) 882-1543

Co-advisor:

Schrand, A.

amanda.schrand@eglin.af.mil

850-882-2203

Metallic fuels are attractive alternatives to organic fuels in energetic materials, due to their higher energy densities and favorable mechanical properties. However, so far the addition of reactive metals into explosive systems has had limited application, primarily because of the relatively slow rate of energy release. It has been proposed that to overcome this limitation, the domain sizes of the fuel be reduced to the nanoscale, where the kinetics may reasonably be expected to approach those of conventional molecular explosives. Investigations of such nanometric metal fuel particles have been limited to a small number of systems and are complicated because oxidation at the surface of the fuel particles is difficult to avoid. At the smallest domain sizes, where the kinetics should be most favorable, the oxide layer at the surface of the metal fuel particles makes up a significant portion of the total volume, thereby introducing unacceptable amounts of inert material. Recent promising experiments have revealed that certain compositions and morphologies of nanometric clusters (e.g. Al13-) are preferentially resistant to unintentional oxidation. A new research program underway at AFRL/RW aims to use modern cluster beam deposition techniques to search through a wide range of nanocluster compositions and morphologies-quickly-and to produce sufficient quantities of material to evaluate their macroscopic energetics and stability. Nanoclusters produced by laser vaporization, buffer-gas condensation, and/or supersonic expansion in vacuum will be formed into a beam and soft-landed onto a substrate. Varieties of pure and mixed clusters will be explored and include novel metal/metal-oxide core-shell nanoclusters as a means of improving the intimate contact between the oxidizer and fuel. The composition, morphology, and reactivity of these nanoclusters will be probed before and after deposition using conventional spectroscopies, mass-spectrometry, calorimetry, and surface science methods.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.02.B5464: Nanoscopic Defects in Energetic Materials

Lindsay, C.M.

(850) 882-1543

Co-advisor

Schrand, A.

amanda.schrand@eglin.af.mil

850-882-2203

It is generally accepted that voids, pores, grain boundaries, and other defects in energetic materials have a profound effect on their mechanical properties, initiation sensitivity, and detonation dynamics. While there have been many theories and models developed to describe such phenomena, there is no consensus as to the relative importance of the various physical processes that impact these properties. The prime reason for this uncertainty is that there exist few experimental data on the concentration and morphology of voids, pores, and other defects in energetic materials important to munitions, particularly at the nanoscale. Alleviating this technical deficiency is critical given the ever increasing role that nano-engineered materials are expected to play in the future. This project aims to identify, evaluate, and implement a variety of experimental techniques capable of probing nanoscopic void/defect structures in energetic materials, and correlating these findings with results from traditional energetic materials sensitivity measurements. Defect characterization techniques to be investigated may include, but are not limited to positron spectroscopies and microscopies, x-ray diffraction (XRD), and scanning electron and atomic force microscopies (SEM & AFM). Each methodology will be evaluated based on its ability to quantify the concentration and morphology of the defects and voids present in energetic materials. Correlations of these measurements with bulk properties, material processing methodologies, and computer simulations will also be investigated.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.02.B7106: Meso-structure – Property – Performance Relationships in Energetic Materials

Sunny, G.

(850) 882-1462

The loading and performance requirements on energetic materials for Air Force applications are becoming increasingly severe. Understanding of the processing – structure – property – performance relationships, particularly at the meso-scale, is critical to enable the design and use of energetic materials. Several research areas are required to develop this topic experimentally, theoretically, and computationally: non-shock and shock initiation and growth of reaction/detonation; microstructural quantification and analysis, particularly of damage; material design and formulation to enhance performance and insensitivity/survivability; pressure-strain rate-temperature dependent material properties, namely of polymers, particulate composites, and energetic materials.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.02.B7454: Agile Munition Vehicles Sciences

Pasiliao, C.L.

(850) 882-8221

We conduct research on the coupled interaction of fluid, structural, thermal, and material dynamics applicable to high-performance weapon airframes. The research includes multidisciplinary approaches in theoretical, computational, and experimental fluid and structural dynamics, and multifunctional materials. We specifically seek to characterize the fundamental physics dictating the overall vehicle controllability, agility, lethality, and survivability. The products of this research will lay the foundation for development of methodologies and tools to exploit the physics of agile, maneuvering weapon airframes of all size scales and speed regimes applicable to tactical weapons in transition between the three phases of flight: (1) air-launch, (2) in-transit, and (3) terminal (e.g., low Reynolds number micro-scale airframes, air-launched unitary subsonic to supersonic guided bombs, air-launched supersonic to low hypersonic air-intercept, and long-range strike weapons). Research opportunities exist in the characterization, control, and exploitation of aero, structural, thermal, and material dynamics that enhance munitions operational capability.

Keywords: Fluid dynamics; Structural dynamics; Thermal dynamics; Computational fluid dynamics; Aeroelasticity; Aerothermodynamics

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.02.B7493: Multidisciplinary Approaches for Effectively Modeling Munition Airframes

Dudley, J.G.

We conduct research on the coupled interaction of structural, thermal, and fluid dynamics for weapon airframes. This research includes a combination of theoretical, computational, and experimental approaches. We specifically seek to quantify the fundamental physics that dictate the underlying effects on the overall vehicle controllability, agility, lethality, and survivability. Complicated, three-dimensional flows, ranging from Stoke’s through hypersonic plasma-generating regimes coupled with highly non-linear thermally dependent materials, must be considered due to the wide operational envelope of USAF munitions. These combined aerodynamic, structural, and thermal environments may be detrimental to a weapon’s operational capability during a terminal maneuver. Many unique challenges are posed due to the combined non-linear effects coupled with decreasing response times as kinetic effects are maximized.

Research opportunities exist in the characterization, control, and exploitation of multi-disciplinary approaches that enhance a munitions operational capability. Specifically:

(1) Prediction and characterization of turbulent flow phenomena and transition to turbulence utilizing: DES, LES, and DNS approaches for external and wall-bounded flows; turbulence model treatment; real-time statistics modeling of turbulence; and convergence monitoring of stationary flow- fields.

(2) Development of high fidelity computational approaches focusing on multi-disciplinary capabilities, such as high order unstructured/structured methods addressing dissipation/dispersion error analysis; real-time, adaptive mesh refinement optimization; unified flow solvers combining the Navier-Stokes and Boltzman equations and chemically reacting flows; and Cartesian and immersed boundary methods for viscous flows.

(3) Utilization of high and low speed flow control methods (both passive and active) for weapon stability and maneuverability through adverse environments such as turbulent shear layers.

(4) Reduced-order modeling with Proper Orthogonal Decomposition (POD) and stochastic estimation approaches for incompressible, highly compressible, and multi-disciplinary flow-fields.

(5) Analysis for high speed compressible flows, to include aero-optics, thermal environment management (active cooling systems, flow control), and shock capturing and boundary layer interaction.

Keywords: Fluid dynamics; Structural dynamics; Turbulence; Weapon airframes; Reduced-order Modeling; Computational fluid dynamics; Flow control

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.02.B7604: Detonating Systems Research

Welle, E.J.

(850) 883-0581

This research will focus on the understanding of fundamental detonation phenomena. Most conventional explosive models are typically described as composite models, which means they treat a complex reacting flow system with 100 to1000’s of chemical reactions and intermediate material states as having only two. Those two states are joined by a reaction rate rule that governs how energy is liberated by moving between those states. We are conducting research to determine how to resolve such reaction pathways by going from 2 to n-number of states that allow for more useful predictive capabilities. Small scale experiment is being invented or matured to facilitate the measurement of needed material characteristics such as equations-of-state for the unreacted, partially, and fully reacted energetic materials. Typical measurement techniques include dual streak cameras, Photon Doppler Velocimetry, and high-speed imaging that can be resolved to the nanosecond or subnanosecond timescale. The work will also include assessment of conventional hydrocode based reactive flow models to determine their physical relevance to problem sets of interest. The Associate will be able to design and participate in the execution of complex optical experiments, become familiar with conventional reactive flow models, design experiments with modelers, and report work in refereed journals or conferences that are open to the general community or limited based on work content.

Keywords: Detonation; Explosive; Optical diagnostics; Equation of state; Photon Doppler Velocimetry; Shock to detonation; Thin pulse initiation; Explosive microstructure; Laser interferometry

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.02.B7623: Shock Physics

Lambert, D.E.

(850) 882-7991

This research opportunity focuses on the fundamental understanding of shock physics in inert and chemically reacting systems. A persistent need remains in the understanding of material response under shock loading, specifically in the area of high-fidelity experiments and measurements. Emerging “mesoscale” modeling approaches have highlighted shortfalls in the conventional characterization methods treating the materials specimens as continuum, or homogenized fields. Current line VISAR (velocity interferometer system for any reflector), digital image correlation (DIC), and photonic Doppler velocimeter (PDV) for ultrahigh-speed image intensified cameras (IIC) and time-resolve emission spectroscopy are available for this research in quantifying the material states of impact shock-loadings. The research will emphasize new opportunities and capabilities in characterizing (both analytically and experimentally) the mesoscale constituent response of heterogeneous and particular materials. A broad range of material systems are considered for this research, including specific geomaterials and soils to nanoparticle reactive materials capable of rapid self-oxidation, to high-energy explosive compositions. We are interested in the broad range of research topics, which include new equations of state, improvements to existing EOS descriptions and models, improved diagnostics or implementations of existing, and advancing our understanding of the constituent response at mesoscale and how to link that response up through the macro-level responses. This research will rely heavily on the interactions between numerical simulation, experiment, and theory with the primary goal of drawing each to comparable fidelity and common basis of comparison.

Keywords:

Shock; Hugoniot; Equation of state; Detonation; Mesoscale; Interferometry; Particulate mechanics;

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.03.B5434: Cooperative Control of Air Armament

Pasiliao, E.L.

(850) 883-2563

Research is in progress on the cooperative control of air armament designed to detect, identify, and attack ground targets. Although many cooperative system approaches model the uncertainty of the environment, they fail to address risks associated with poorly specified stochastic models of the environment, the adversary, or the cooperating agents. Cooperative agents must optimize "local" objectives that ideally translate into achieving global or collective objectives. Because information gathering and decision-making are distributed, there is considerable uncertainty about the actions of independent team members. It is quite possible that the independent pursuit of local objectives implicitly results in team members taking on adversarial roles as competitors for limited resources or tasks. Components of this research include risk sensitive optimization and risk management techniques such as Conditional Value at Risk, applied to situations where enemy forces are attempting to deceive or destroy friendly forces. Other research components include the development of distributed algorithms for policy generation, with real-time policy updates based on observation or prediction of the behavior of teammates or adversaries.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.03.B7085: Centralized Control Algorithms on a Wireless Grid

Pasiliao, E.L.

(850) 883-2563

*Description

The purpose of this topic is to develop novel highly parallelizable exact and heuristic solutions to the sensor fusion, path planning, and target assignment problems for multiple munitions. In the early part of cooperative control, most of the research was done through a centralized decision process where all the raw data from the unmanned aerial vehicles were collected and processed in a single data base. When it became apparent that the communication architecture could not support the high bandwidth requirements of moving all relevant information to a central processor, the research community began to look at decentralized heuristics for combining measurement data, coordinating flight plans, and other cooperative endeavors. A huge disadvantage of decentralized solutions is that it is suboptimal. They are never better than the solution derived using all available information and their solution quality is difficult to evaluate. Another bottleneck is the limited computational resources on munition. With these earlier difficulties in mind, we are starting to look at using the wirelessly connected munitions as a computer grid that is capable of solving the cooperative control problems in a centralized and optimal manner. The idea of a computer grid on a wireless network brings unique challenges since data links are noisy and continually reconfiguring itself, some processor may leave the grid temporarily or permanently. We are looking to develop and analyze centralized algorithms for collaborative control of munition systems that can robustly adjust to a constantly changing computing environment.

*Keywords:

Optimization; Sensor fusion; Path planning; Target assignment; Computer grid; Wireless;

*Eligibility

Citizenship: Open to U.S. citizens and permanent residents

Level: Open to Regular and Senior applicants

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.03.B7505: Basic Study of Solar Activity

Touma, J.E.

(850) 883-0876

The sun plays a major role in affecting the space environment in which Air Force systems operate and has a major effect on guided weapon systems. Electrical and magnetic effects in plasmas play an important role in the phenomenon that we observe in the sun. An understanding of the basic processes that drive the sun is necessary in predicting the sun’s behavior and eventually how Air Force systems are affected. Theoretical research areas exist in the triggers of coronal mass ejections and solar energetic particles and flares. We are also interested in non-conventional basic research areas such as the electric sun model, electric discharge as the source of solar radiant energy, magnetic reconnection, and electrical properties of the photosphere and chromosphere. Applicants must be US citizens.

Keywords:

Electric sun; Coronal mass ejection; Chromosphere; Electric discharge; Photosphere; Solar plasma; Solar flares; Solar energetic particles; EM effects on plasmas

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.03.B7506: Computational Modeling of Aerothermoelastic Effects

Pasiliao, C.L.

(850) 882-8221

We conduct research to characterize the relevant physics associated with aerothermoelastic effects for hypersonic weapons, and develop methods for controlling the aerothermoelastic behavior. Design of munitions traveling at hypersonic speeds is an inherently challenging task due to the fact that the system dynamics are nonlinear and highly coupled in aero, structural, and thermal dynamics as they transition between the three phases of flight: 1) air-launch, 2) in-transit, and 3) terminal. Hypersonic vehicles have non-standard dynamic characteristics which are difficult to model, such as: structural modes decreasing with increasing temperature; vibrations in the fuselage causing thrust, lift, drag, and pitching moment perturbations; and a wide range of speeds/altitudes throughout the operational envelope leading to coupling effects and nonlinearities.

Research opportunities exist in the characterization, control, and exploitation of aero, structural, and thermal dynamics that enhance a munitions operational capability.

Keywords: Aerothermoelasticity; Aeroservoelasticity; Hypersonics; Computational Fluid dynamics; Structural dynamics; Thermal dynamics

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.05.B4001: Modeling Complexity in Ignition of Energetic Materials

Lambert, D.E.

(850) 882-7991

Over the past 150 years, there have been countless studies of the reactive behavior of energetic materials. However, there is not yet a deep, quantitative understanding to predict the ignition threshold from mechanical and/or thermal stimuli in terms of basic physical and chemical properties. Current understanding of ignition sensitivity is still empirical and qualitative. Another example is the effect of additives (reactive or inert) on reactive behavior. The difficulty in achieving such a fundamental understanding is attributed to the fact that underlying physical processes are controlled by heterogeneous mechanisms, which are often localized and cannot be adequately described by average parameters such as pressure, density, and temperature. Global behavior represented by these thermodynamic variables does not, by definition, describe the subscale physics that involve strongly coupled, transient, thermal, physical, and chemical processes, and microstructure evolution. The one complicating factor that is often ignored is that explosives are a stochastic medium.

Various efforts combine both computational modeling and new diagnostic techniques that can probe fast material behavior at the crystal or grain level. Computational effort involves direct simulations of mesoscale response behavior using continuum codes and representative microstructures at the grain level. However, results are exceedingly complex and require careful data analysis to extract physical understanding. Plus, they are known to be dependent on models and materials properties used for the simulation. Therefore, the impact of direct mesoscale simulation has been limited to understanding qualitative behavior of hot-spot formation (energy localization) and its distribution, and what is needed to gain reliable qantitative results.

We are interested in an alternative approach to modeling the ignition of energetic materials, in which hot spots are described by a statistical distribution. Such a distribution depends on the details of the materials at the grain scale and loading. However, the evolution of the distribution may be modeled by mean field variables (concept of enslaving) and microstructure related parameters. In addition, the distribution can be viewed as a path from hot spots to "burn" over a bridge of chemistry at the appropriate condition of temperature. Thus, the distribution is seen as synonymous to the distribution of reactive interface across which mass transform from solid to gas. In this view, the interface will acquire a fractal-like feature. The challenge is to develop a conceptual framework and a working model that are simple, but complex enough to capture the essential microscale physics that occur in stochastic media.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.05.B4002: Scale Effects on Dynamics of Explosively Driven Reactive Products

Lambert, D.E.

(850) 882-7991

Reactive metal particles, ranging from a few microns to millimeters, are commonly added to explosives to improve blast effect or underwater performance. In some instances, the particles are juxtaposed to the explosive. The underlying assumption is that the combustion of metallic particles augments blast overpressure through the heat release associated with the reaction. We are interested in the development of a robust, physics-based computational model to gain improved description of the multiphase flow dynamics where solid particles are considered deformable and can even undergo phase transitions.

Particular problems of interest include scale effects on the dynamics of the particle dispersal process and the reactive behavior of the particles within the explosive products and air. Through a high-fidelity modeling, we would like to gain insight into a "slingshot effect" where particles of certain sizes can out-run the blast wave front. We are also interested in determining the temperature history of the particles during explosive dispersal as it relates to melting, vaporization, chemical ignition, and the propagation of burning front. Another process of interest is the fragmentation or atomization of particles in flight or at impact with a "rigid" wall. Because the particles are accelerated to high speeds on the order of 1-2 km/s, melted particles (or partially melted particles) may further fragment in flight or at impact and cause a large increase in reaction surfaces. Again there is little fundamental characterization of such processes. We are interested in constructing a computational tool to create a virtual simulation environment for the reactive flow research.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.05.B5477: Bench Top Energetics

Fajardo, M.E.

(850) 882-4212

The incorporation of nanometric (sub-micron size) metal fuel and oxidizer particles into energetic materials is a promising approach to increasing significantly the systems-level performance of munitions. We propose to exploit the phenomenon of laser driven shock initiation of energetic materials to enable bench-scale testing of initiation mechanisms and energy-release reaction kinetics of nanometric energetic materials via methods which utilize a minimum of often rare and expensive energetic materials, and which routinely yield rapid repetitive energetic events. Direct laser initiation of energetic materials involves a complicated combination of shock, electronic, and thermal effects that are very difficult to relate to real-world chemical-explosive-driven initiation processes. We will use laser driven flyer plates to decouple the laser photon flux from the energetic material, reducing interference from direct electronic and thermal initiation mechanisms, thus greatly simplifying matters. The technology for producing laser driven flyers is advancing rapidly, thanks to efforts in a number of laboratories around the world. We will exploit as much of the state-of-the-art as feasible, including the use of advanced numerical simulation techniques to model our bench top experiments. We will adopt the "nanoshock target array" approach for generating repetitive energetic events pioneered by Dlott and coworkers. In this method thin films of energetic materials are prepared on a transparent substrate "target coupon" which is rastered mechanically through the fixed focus of a pulsed laser beam. Our novel adaptation will include the laser driven flyer plate intermediate, and a target-in-vacuum capability. The expansion of reaction intermediates into vacuum will quench subsequent reactions and preserve these intermediates for spectroscopic interrogation. Conversely, we will also employ buffer gases and "glass confined" experimental geometries as necessary to permit longer reaction times. The spectroscopic diagnostics will permit testing of common modeling assumptions, such as local thermodynamic equilibrium, and will be capable of measuring conditions in the reacting flow such as rotational and vibrational temperatures.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.08.B0584: Structural Dynamics

Foley, J.R.

(850) 883-0584

Research will involve designing and performing experimental studies of the time- and frequency-domain response of both simple and complex mechanical systems to high-amplitude, short duration impulsive loads. We are also interested in structural dynamics experimentation, analysis, and/or simulation. Opportunities exist to study the following: (1) direct simulation and/or experimental validation of transient time- and frequency-domain system response (using such methods as modal analysis); (2) estimation of the dynamic state of the system using model-based estimation techniques; (3) development of novel experimental testing methods for evaluating the shock-survivability and response of materials, sensors, electronics, and mechanical interfaces; (4) development of methods and metrics to characterize the internal mechanical environment of a complex electromechanical system under impulsive loading; (5) modeling and design of highly-coupled experiments (i.e., design of experiments), which could include multiphase physics (e.g., blast-driven impact); and (6) development of innovative methods for increasing computational efficiency and accuracy of transient dynamic simulations, with specific focus on propagation through interfaces with parametric variance (i.e., uncertainty in interface properties).

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.08.B2564: Vision-Based Guidance and Control

Curtis, J.W.

(850) 883-2564

Research opportunities are available to explore the intersection of computer vision with the guidance and control of unmanned aerial vehicles and munitions. Vision-based sensors are typically small, lightweight, and inexpensive; these qualities make them well suited for deployment on next-generation unmanned vehicles and weapons. There is a gap in the literature regarding the use of vision-only sensing for terminal guidance and many fruitful lines of research could be opened in order to investigate the limitations and advantages offered by monocular or multicamera sensor platforms. Work is currently in progress that explores the use of visual information to successfully estimate position and attitude; this navigation-specific work might dove-tail nicely with an investigation of vision-based guidance law design. Furthermore, since a visual sensor can be used for both ego-estimation and target relative position and motion, a possibility exists to develop an integrated guidance and control system based primarily on information derived from one or more cameras.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.08.B6110: The Science and Technology of High Velocity Impact

Chhabildas, L.C.

(850) 882-6110

We have a gunnery range that allows projective launches over the range of meters per second to 8 km/s using smooth bore compressed gas gun, oblique impact gun, and powder guns, explosively formed projectiles, or shaped charge jets. Use of these high speed projectiles with targets can result in high pressures in the media. The smooth bore guns provide precision controlled impact conditions to determine the high pressure equation-of-state, constitutive behavior, and failure of a wide variety of materials. These are complemented with time resolved (nanosecond resolution) interferometry referred to as VISARs, and PDV gauges. Current applications include determining the target response for a variety of materials including but not limited to metals, bulk and nano-energetics, reactive materials, liquid crystals, and porous geologic media. In addition, opportunities exist to further the current technologies to probe heterogeneous materials such as energetics and porous media at a microstructural level experimentally, theoretically, and computationally. Other topics include determination of fracture and fragmentation properties of solids and liquids.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.12.B1103 : Information Theory and Physics

Touma, J.E.

(850) 883-0876

Our goal is to quantify and process information from multiple, potentially disparate sources in a manner that is conductive to eventual online implementation. The data sources and application scenarios that will be under consideration will certainly be stochastic in nature, hence the ability to extract the maximum amount of information will be vital. Notionally, we want to consider so-called "worst case scenario" where data sources are of poor quality and scenario definitions are poorly defined. Nevertheless, the ability to manipulate available information should in no way be constrained by such definitions and should remain both modular and scalable. Although information can be expressed within numerous coordinate systems, the final result must be amiable to interpretation by a human decision authority. Research in this area will focus on investigating various methodologies for representing, extracting, communicating, and ultimately assigning value to the available information. We will make use of recent technical advances from various research communities with a particular interest in information theory, information geometry, along with quantum and statistical physics to achieve the aforementioned goal.

Keywords: Information Theory, Information Physics, Information Geometry, Quantum Mechanics, Sensor Fusion, Statistical Mechanics, Sensor Networks, Bayesian Statistics

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.12.B1130: High Performance Advanced Materials

Bolden, N.W.

(850) 883-2594

Our research focuses on the design and characterization of low-cost, advanced materials for high performance munitions’ airframes. This includes both traditional and multi-functional composites and ultra-high temperature materials. Particular interests are in novel systems that can provide extreme thermal, mechanical, and electrical properties to conventional materials as well as smart capabilities such as sensing, self-healing, self-cooling, morphing, threat protection, etc. The objectives of this project are to identify, produce, and characterize high performance advanced materials with optimized thermal, mechanical, and chemical behaviors. All aspects of synthesis, characterization, fabrication, and processing are addressed under this topic.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.13.B0830: Trusted and Flexible Autonomous Systems

Murphey, R.A.

(850) 882-2962

Autonomous weapons are ground, air, or sea launched kinetic munitions that utilize on-board and networked information to better understand an uncertain, adversarial battlespace and make decisions to maximize engagement goals. This area of study is focused on increasing flexibility and adaptability of weapons to meet operator intent even in environments & situations they were not designed for. There are 4 primary areas of interest for study: 1. Components & systems that are inherently reconfigurable are necessary to build autonomous systems with greater flexibility and therefore an ability to achieve the mission despite unforeseen impediments. AFRL/RW has conducted a number of studies that indicate that bio-inspired wide field-of-view sensing and proliferated sensing – processing – actuation – morphing/adaptation inherently provide more potential for flexibility in autonomous behaviors. 2. Awareness, structure, and reasoning that allow inference of high level tactics from proliferated sensing or naturally create robust hedges to extreme outcomes will provide greater flexibility in autonomy. Ultimately methods of inference and robustness can result from either a deliberate or minimalist approach but the focus is always on the “correctness” of understanding, decisions and outcomes. 3. A mathematical control language for autonomy, that defines trust admissible regions/ patterns/groupings for autonomous decisions, would enable rapid & robust reconfiguration of a system. Results in theorem proving, language parsing, computing theory and complexity, & quantitative local analysis indicate that a constructive framework for flexible autonomy is possible. 4. “Cognitive matching” – whereupon a machine anticipates the human's decisions & actions while the human gains insight into the machine decision process - can build trust with operators using autonomous weapons. Cognitive matching experiments in AFRL have shown that machines that measure operator work-load can tailor information content and forestall operator decision failures.

Keywords: Trusted autonomy, reasoning systems, robust decision making, super quantiles, computing theory; human supervised autonomy.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.13.B0831: Networked Control of Service Based Functions

Murphey, R.A.

(850) 882-2962

The conventional design of smart weapons, unmanned systems, and networked systems at large, is based on techniques that feature platform-centric dedicated sensing, estimation, communications, control and computation. However, given the networked nature of our world, this approach is self-limiting. Weapons (and unmanned systems in general) are becoming increasing complex, increasingly small, and are expected to have greater levels mission flexibility within a networked system of systems. On a single platform there will be a high demand for space and power efficient functions which lead one to consider how sensors could be re-tasked to service multiple functions (control loops). In component based control, service oriented programming techniques have demonstrated that complex computing behaviors (services) can be performed quite efficiently when the service (e.g. contract) is separated from the components. Motivated by this approach, consider a weapon architecture that consists of a networked collection of devices (e.g. sensors, processors, effectors) and functions (filters, guidance laws, controllers, and so on). A service host subscribes some subset of devices to a particular service request, and establishes a subnet that defines the function of each device, the interconnection of devices, switching limitations (to other services), and priorities. Virtual services could be distributed across a network in a seamless fashion. Services might include a seeker, navigation, surveillance, multi-aperture surveillance or communications (beamforming), effects, and so on. Ultimately, services are introduced by an operator. However, once created, one virtual service might spawn other service requests and might even be able to terminate others. The areas for study include: definitions and protocols for spawning services; linked communications and control architectures that support distributed sensing and computing with timing guarantees; hedging strategies for robust service execution; dynamic allocation-reallocation, assignment and partitioning strategies; performance guarantees and complexity theorems.

Keywords: Networked control, service based control, dynamic assignment, complexity, robust networks.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.13.B0832: Bioinspired Principles for Autonomous Munitions Systems

Dickinson, B.T.

(850) 883-2645

Insects utilize a wide range of sensing modalities to achieve robust and agile flight. These modalities are often occur in arrays composed of noisy mechanosensors in numbers of hundreds, thousands, or more; and are distributed over organs or locations of the body according to their function. In contrast, modern guidance, navigation and control designs rely on feedback from local and precise instrumentation such as inertial measurement units, gyroscopes, global positioning systems and pitot tubes. We aim to derive scalable principles from the existing knowledge base surrounding the information processing and sensing modalities of natural flyers to develop fundamental and scalable control methodologies that increase robustness and minimize the human interaction necessary for effective engagement of munitions platforms. This may include, but is not limited to, biologically inspired and derived methodologies for the feedback of munitions attitude, atmospheric turbulence, and wind shear or gusts.

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.13.B0834: Low Reynolds Number Flyers with Flexible Wings in Turbulent Flows

Sytsma, M.

(850) 882-0394

Small munitions are characterized by diminutive vehicle size, low flight speeds, and low Reynolds number aerodynamics. This class of munition are highly susceptible to free-stream turbulence instabilities, but the environments these vehicles are envisioned to operate in can be highly turbulent and unpredictable. Vehicle stability in such cases is therefore paramount to mission success, but an equally important concern is that such vehicles must be agile enough to maneuver in constrained environments without crashing. Current in-house research focuses on the interaction of wind-tunnel generated free-stream turbulence with fixed rigid models. Research opportunities exist in testing the effects of turbulence on models that exhibit varying degrees of structural flexibility as well as novel mitigation and control measures. The goal is to develop an understanding of what can be done to decrease the deleterious effects of turbulence on controlled flight while at the same time augmenting agile vehicle performance.

Keywords: Low Reynolds Number, micro, unmanned, vehicles, system, free-stream turbulence, flight stability, aero-structural interaction, flexibility, mitigation

AFRL/RW EGLIN AF BASE, FLORIDA

SF.45.13.B1126: Fundamental Research of Novel Energetic Materials

Schrand, A.

(850) 882-2203

The goal of our team is to discover, develop, integrate and transition energetic materials technology that maximizes lethality, survivability and safety for air-delivered munitions. We study the basic processes and scientific phenomena that are necessary to predict, design and characterize energetic materials. A variety of topics are being considered for enhancing the energy density of materials based upon improved reaction rates while maintain stability under ambient storage conditions (ie. Room temperature, humidity). Specific topics of interest include: 1) energetic films via spin casting of fuel-oxidizer blends, 2) light tunable sensitization of energetic materials, 3) self-assembly of thermite-based structural materials, 4) scale up processes such as resonant acoustic mixing and 5) synthesis of energetic nanoparticles using superfluid helium droplet assembly and other techniques. A successful candidate will possess a strong multidisciplinary experimental background in physics, chemistry and materials science/engineering with knowledge of modeling and simulation techniques.

References:

1. Prakash, A., A.V. McCormick, and M.R. Zachariah, Tuning the Reactivity of Energetic Nanoparticles by Creation of a Core−Shell Nanostructure. Nano Letters, 2005. 5(7): p. 1357-1360.

2. Ferrando, R.; Jellinek, J; and Johnston, R.L. Nanoalloys: From Theory to Applications of Alloy Clusters and Nanoparticles. Chem. Rev., 2008, 108 (3), pp 845–910.

3. Heting Li, Mohammed J. Meziani, Fushen Lu, Christopher E. Bunker, Elena A. Guliants and Ya-Ping Sun Templated Synthesis of Aluminum Nanoparticles - A New Route to Stable Energetic Materials. J. Phys. Chem. C, 2009, 113 (48), pp 20539–20542

4. Lei Zhou, Ashish Rai, Nicholas Piekiel, Xiaofei Ma and Michael R. Zachariah

Ion-Mobility Spectrometry of Nickel Nanoparticle Oxidation Kinetics: Application to Energetic Materials. J. Phys. Chem. C, 2008, 112 (42), pp 16209–16218.

5. Rusty W. Conner and Dana D. Dlott. Time-Resolved Spectroscopy of Initiation and Ignition of Flash-Heated Nanoparticle Energetic Materials. J. Phys. Chem. C, 2012, 116 (28), pp 14737–14747.

6. Yong Qin, Yang Yang, Roland Scholz, Eckhard Pippel, Xiaoli Lu, and Mato Knez. Unexpected Oxidation Behavior of Cu Nanoparticles Embedded in Porous Alumina Films Produced by Molecular Layer Deposition. Nano Lett., 2011, 11 (6), pp 2503–2509.

7. William K. Lewis, Barbara A. Harruff, Joseph R. Gord, Andrew T. Rosenberger, Thomas M. Sexton, Elena A. Guliants, and Christopher E. Bunker. Chemical Dynamics of Aluminum Nanoparticles in Ammonium Nitrate and Ammonium Perchlorate Matrices: Enhanced Reactivity of Organically Capped Aluminum. J. Phys. Chem. C, 2011, 115 (1), pp 70–77

Keywords: Energetics, Thermites, Nanoparticles, Energy density, Reactivity

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B0118: Solid-State Laser Source Development

Schepler, K.L.

(937) 528-8661

We investigate and develop new infrared (1.5-12 μm) materials, devices, and technologies that have potential for high lasing efficiency, broad wavelength tunability, and robust operation. Research includes exploration and development of new solid-state laser media such as Cr2+ doped into ZnSe and analogous semiconductor host materials. Lasers with direct emission throughout the infrared spectrum and room-temperature operation are sought. Current projects include demonstration of high-power modelocking, Q-switching and CW operation of Cr2+:ZnSe, demonstration of sub-ns pulse operation of a Tm μ-chip oscillator-fiber amplifier, and demonstration of > 2-μm fiber lasers. Rapid tuning, beam control via guiding structures, and beam switching are also performance issues. Infrared lasers (bulk, fiber, and semiconductor types) are also being developed for use as pumps of new quasi-phasematched nonlinear media such as orientation patterned gallium arsenide. Areas of interest include spectroscopy of infrared laser materials, beam transport in infrared fibers and waveguides, and infrared nonmechanical beam steering. Facilities are available to perform spectroscopic measurements of absorption, excited-state absorption, fluorescence, fluorescence lifetime, and ultrashort pulse characterization. A variety of pump lasers are available including Nd:YAG lasers, Tm fiber lasers, Tm,Ho:YLF Q-switched lasers, and semiconductor lasers for measuring spectral content, power, beam quality, and thermo-optic properties of new laser materials.

Keywords:

Solid-state lasers; Tunable lasers; Infrared lasers; Fiber lasers; Infrared fiber transmission;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B2220: Radar Systems Theory

Himed, B.

(937) 528-8124

This task involves research and theoretical analyses concerning the development of new techniques and radar system concepts (spatially and spectrally diverse radars), which provide greatly improved performance for ground, air, and space surveillance (passive and active) radars; synthetic aperture (and “all target” imaging) radars; sparse arrays; multi-static radar; distributed RF sensors; and multiple aperture interferometric radars. Current topics include suppression of range-angle-Doppler ambiguities, analysis of ambiguity induced limitations from an information theoretic viewpoint, interferometric clutter cancellation and interferometric height discrimination, automatic focusing, preprocessing for clutter and electromagnetic interference suppression prior to space-time adaptive processing, and multifrequency waveform diverse radars for persistent surveillance combined with high fidelity imaging and feature extraction for processing, exploitation and dissemination (PED). Extensive computer modeling, simulation facilities, and experimental data sets are available to support this research.

Keywords:

Adaptive process; Clutter; Dual frequency; Modeling; Radar; SAR; Simulation; Target recognition;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B4480: Electro-Optical Sensor Research

Rabb, D.J.

(937) 938-4392

Our research focuses on the following:

(1) Algorithm development and signal processing for laser radar. Techniques of interest include, but are not limited to: turbulence mitigation, phasing of coherent apertures, streamed processing high bandwidth waveforms, photon counting arrays with reduced computation, micro-scanning, stitching of imagery, and data exploitation.

(2) Eye-safe transmitters for coherent laser radar. The objective is to develop efficient laser-based systems capable of gathering multidimensional images, where the dimensions can include spatial (x,y,z), spectral, polarization, and vibration characteristics. Transmitters with agile wavelength and with waveform agility are desirable, as they can be used for multiple imaging modes. Transmitters need to be capable of high peak powers with minimal stimulated Brillouin scattering effects for continuous wave and especially pulsed applications.

(3) Shot noise limited coherent receivers for laser radar. Full waveform reception multi-mode laser radar signals are desired. Also of interest are techniques which can help to implement conformal/distributed coherent apertures, including non-mechanical beam steering and photonic integrated circuits among others. Receive apertures that can be used for transmitting or passive imaging at other wavelengths as well are preferable due to the increased functionality.

Keywords: Electro-optical imaging; Laser radar; Ladar; Optical phased arrays

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B4697: Mixed-Signal Component Technology

Watson, P.

(937) 528-8709

Affordable next-generation radar systems necessitate innovative system architectures and mixed-signal circuit technologies which have unprecedented levels of component integration. Insertion of monolithic mixed-signal integrated circuits (ICs) will lead to reduced system cost, size, weight, and power consumption. Shrinking solid-state device sizes and higher integration densities are making the fabrication of mixed-signal ICs possible; however, this brings up several new design challenges. Research focuses on employing the most advanced models and design automation tools to develop novel low-cost monolithic mixed-signal ICs. A critical part of the design is the identification of affordable IC process technologies and the level of integration achievable, while at least maintaining the current system performance. The design of high-frequency mixed-signal ICs must take into account the noise, parasitics, and cross talk resulting from the high frequencies and integration densities required. We envision that this research will require new design strategies and methodologies.

Keywords:

Mixed signal; Design; Microwave; Analog; Digital; Monolithic; Integration;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B4948: Organic and Inorganic Photonics and Optoelectronics

Nelson, T.R.

(937) 528-8710

Our research is advancing exploratory and innovative concepts in photonic and optoelectronic materials, devices, and components for Air Force applications. Traditionally, this work has focused on semiconductor technology for generation, manipulation, and detection of infrared radiation (IR), from near-IR (NIR) through short-wave, mid-wave, and long-wave regions (SWIR, MWIR, and LWIR, respectively), including into the THz range of the electromagnetic spectrum. Efforts are now underway to blend organic (polymers, bio-derived materials) with traditional inorganic semiconductor materials for increased functionality, reduced cost of fabrication, as well as reduced size, weight, and power consumption for future Air Force platforms. Application areas include novel IR sources and detectors for coherent or incoherent active and passive standoff detection (LADAR/LIDAR); new methods for light modulation for optical communications, RF-Photonic Links, and optical diverse waveform generation; and new methods for highly integrated photonics systems, such as monolithic integration, printed optoelectronics, and highly dense hybrid integration. The Air Force research site provides a fully equipped class-100 clean room, deposition and materials analysis, e-beam lithography, a host of packaging and integration tools, as well as photonic characterization systems and access to high-performance computing at facilities located on site.

Keywords:

Integrated photonics; Optoelectronics; Biophotonics; Printed optoelectronics; Infrared detectors; Quantum cascade laser;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B4960: Advanced Digital Receiver/Aperture Development

Mumford, P.D.

(937) 255-6427 x4339

Our ultimate goal is to realize fully digital multifunction active arrays with programmable functionality. In this architecture, only the high power and low noise amplifiers at the aperture are analog circuits. Wide-bandgap semiconductors are candidates for these high-power and linear amplifiers. All the amplitude and phase-shifting functions, as well as the beam-forming, are done digitally. Transmit waveforms are generated by direct digital synthesizers and the received signals are captured with very high-speed analog-to-digital converters with deep dynamic range and wide frequency response. True time delay for steering very large wideband agile arrays is also digitally implemented. This architecture requires very high-speed, high-throughput data processing. Commercial simulation tools can facilitate the design of the array aperture and radiators, as well as the components used in the active phased array. Behavioral simulation methodology allows performance prediction of experimental components used in the architecture. Affordability, size, and power consumption are important factors to include in the trade space, but may be considered secondary to advanced performance capabilities. Military RF sensors must operate in extremely dense signal environments (including intentional, unintentional, and co-channel interfering signals). UHF and VHF radars for Foliage Penetration and ground penetration are especially vulnerable because of the dense array of commercial emitters, limited aperture spatial discrimination, wide instantaneous bandwidths, and long integration times required. Research in all areas of RF system design mentioned above is sought.

Keywords:

Microelectronics; Microwave antennas; Microwave electronics; Solid-state electronics;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B5814: Precision Navigation Reference Sensor Techniques

DeVilbiss, S.L.

(937) 255-6127 x4274

Our goal is to research and develop the latest technologies to provide precise Postion, Navigation, Attitude, and Time (PNAT) for military systems operating in any environment at any time. PNAT is the cornerstone in providing an assured reference for distributed sensing and warfare. Research includes investigating inertial sensor technologies and their integration with secondary sensors (preferably passive) that provide precision measurement updates, as well as optimization of the reference solution for the specific distributed or staring sensing task. Potential secondary sensors include jam resistant global positioning system (GPS) technologies, optical sensors using passive image data, light detection and ranging (LIDAR) sensors using ranging data, and software based receivers and navigation using natural signals (e.g., the Earth’s magnetic field).

Current in-house research partially focuses on exploration of military use of global navigation satellite systems (GNSS) and sensor-inertial fusion in constrained environments where GPS may not be available. A critical piece of this research effort involves determining the optimal method for integrating various navigational aiding sensor data into a precision navigation system.

Keywords:

Assured reference; Navigation techniques; Precision navigation; GPS receiver technology; Navigation aids; Software defined radio; Inertial navigation; Global Navigation Satellite Systems (GNSS)

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B5858: Bio-Inspired Systems for Intelligent Information Processing (IIP)

Ewing, R.L.

(937) 528-8122

Bio-inspired passive radar systems incorporate intelligent information processing (IIP) to identify a wide radio frequency (RF) signal processing application range from detection to image identification. Bio-inspired IIP focuses on mixed-signal radar, microwave, coherent source, wavelets, millimeter wave, polymorphic, self-organization, self-assembly, nanoprocessors, and nanosystems of systems architectures to enable real-time information extraction and context processing. The objective of this research is to address a broad spectrum of information fusion, algorithms, and embedded processing for developing IIP passive radar architectures for both receiver and transmission technologies.

Keywords:

Bio-inspired; Radar; Real time; Mixed signal; Wavelets; Polymorphic; Fusion algorithm; Context processing; Nanosystem; Radar processing; Radio frequency signal processing; Millimeter wave; Microwave and passive sensing;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B6349: Radio Frequency Micro-electromechanical System Design, Fabrication, Packaging, and Characterization

Ebel, J.

(937) 528-8698

Micro-electromechanical systems (MEMS) switches offer numerous advantages for radio frequency (RF) systems over competing technologies. Several MEMS technology advantages include low insertion loss, high linearity, and reduced size. Although the reliability of RF MEMS devices has improved dramatically over the last several years, deficiencies in several fundamental areas associated with the technology persist. Areas that we are currently working on include (1) wafer-level encapsulation of the switches, (2) dielectric charging characterization, and (3) metal contact damage evolution. Wafer-level thin-film encapsulation provides discrete device packaging to protect the switches from the environment. Current research efforts focus on the sealing of thin-film encapsulants and characterization of the package hermeticity. The electrical performance and reliability of RF MEMS capacitive switches is dependent on the properties of the switch’s dielectric material. We are conducting experiments to quantify the charging and discharging behaviors of the dielectric materials for capacitive switches. We are also interested in modeling the contact wear mechanics of the mating surfaces for metal contact MEMS switches. Model validation is anticipated through examination and testing of fabricated devices. Device processing and test facilities are available to fabricate and characterize the RF MEMS switches. Device fabrication is completed in an on-site clean room facility. RF probe stations and an environmental chamber are used for electrical characterization and hermeticity experiments.

Keywords:

MEMS; Radio frequency; Dielectric charging; Thin film; Metal contact; Encapsulation; Packaging;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B6350: Investigation and Optimization of Existing and Novel Electronic Devices

Crespo, A.

(937) 255-1874

The goal of this project is to investigate and optimize the electrical performance of existing devices, devising and investigating novel electronic devices (e.g.,nanoelectronic devices). Investigation of these devices through electrical characterization, limited physical characterization, and modeling will enable a better understanding of their limitation and potential. The information produced in this project will push the limits of the current state-of-the-art in electronics.

An example of this research includes, but is not limited to, the optimization of AllnN/GaN HEMTs by investigating changes in electrical device performance due to changes in device fabrication. For this example, components that could be studied are silicon nitride dielectric passivation, ohmic and Schottky contact formation with variations in metal stack components, and surface treatments prior to metal deposition.

References:

Gillespie A, et al: Solid-State Electronics 49(4): 670, 2005

Jessen GH, et al: IEEE Electron Device Letters 28(5): 354, 2007

Keywords:

Transistor; Power; Compound semiconductors; Nanoelectronic; Device; FET; HEMT; Microwave;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B6351: Multichannel Radio Frequency Sensor Processing

Hary, S.L.

(937) 255-3802 x3476

We develop radio frequency sensor processing hardware and software techniques. The use of multiple channels on transmit and receive enables multiple Degrees of Freedom (DOF) processing and Digital Beam-Forming (DBF). Research interests fall into the following categories:

(1) Novel multichannel architectures. The goal is to achieve broad spatial and frequency coverage utilizing multiple simultaneous beams. Architectures should be scalable in number of channels and capability (number of beams, bandwidth coverage).

(2) Sensor signal processing techniques. We are particularly interested in techniques that reduce the per-channel computational requirements, DBF processing requirements, and DOF reduction processing requirements for wide instantaneous bandwidth systems. We are also interested in performance versus cost tradeoffs for adaptive and non-adaptive techniques.

(3) Software compensation schemes. Many multichannel signal processing techniques assume perfectly matched hardware channels. It is desirable to have digital/software compensation schemes that correct for mismatches, or to develop processing techniques that are impervious to channel mismatch. We are interested in research in compensation schemes for Analog (Amplifiers, mixers, transmission lines), and mixed signal (Analog-to-digital Converter) component non-linearity, as well as inherently robust processing algorithms.

Keywords:

Digital receivers; Waveform generation; Digital beam forming; Radio frequency signal processing; A to D converter; Sensor processing;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B6593: Nonlinear Optical Materials and Devices

Peterson, R.D.

(937) 528-8657

We investigate and develop new nonlinear optical devices, primarily for frequency conversion applications. Specifically we are seeking tunable coherent sources in the mid-infrared (2-5 micron) and far-infrared (8-12 micron) spectral regions. We are also interested in beamsteering, modulation, and similar devices based on nonlinear optical materials and processes. Current projects focus on quasi-phasematched (QPM) materials, specifically orientation-patterned semiconductors; although other QPM materials, innovative birefringently-phasematched crystals, and techniques for enhancing performance in more established materials are also of interest. Experiments address optical characterization of candidate materials, demonstration and performance characterization of nonlinear devices, and performance modeling, with the goal of improving material fabrication processes and device designs to optimize performance. Facilities are available for measuring absorption, fluorescence, and scatter, as well as thermo-optical properties. A variety of lasers are available for use both in material characterization and as pump sources for frequency conversion and other nonlinear devices. Optical parametric oscillator testbeds are available, along with equipment for measuring device output power, spectral content, beam quality, and other performance parameters. AFRL also has a class 100 clean room and facilities for fabricating periodically poled ferroelectric materials, for bonding semiconductors and other optical materials, and for MBE growth of GaAs.

Keywords:

Nonlinear frequency conversion; Nonlinear optical materials; Quasi-phasematching;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B6851: Secure, Reliable, and Responsive Distributed Sensor Networks

Mumford, P.D.

(937) 528-8553

The goal of multilayered sensing is to utilize all available sensors (wired and wireless; friend and enemy; static and mobile; air-, space-, and ground-based) to establish a pervasive sensor sphere capable of simultaneously monitoring the region of interest at different ranges and granularities. An important part of this vision is the development of inexpensive and easy-to-deploy secure, trusted wireless and wired sensor networks.

Small and cheap mobile wireless sensor nodes already exist, but traditional distributed computing and networking technologies cannot make efficient use of this new hardware because it is severely constrained in terms of processing power, memory, and battery life. Further complicating the problem is the desire to use these networks to provide situational awareness and threat detection in hostile environments. This introduces the need to reliably handle irregular network loads (such as when a threat is detected) in a time-sensitive manner while simultaneously securing the network against the environment, and software and hardware attack.

This emerging research area is broad and requires synthesizing and expanding on a variety of current fields. Traditional network research such as ad-hoc network formation, quality of service guarantees, and priority-based routing need to be re-examined with the particular needs of mobile sensor networks in mind. Security concerns related to the vulnerability of individual nodes need to be addressed, possibly by developing anti-tamper technologies or taking as much global information (such as network topology) as possible out of band. Distributed computing techniques such as distributed data structures and query aggregation need to be considered in light of possible node mobility and the severe resource limitations and security concerns of these applications. In short, this area offers opportunities for researchers from a wide range of backgrounds to contribute to a new and increasing important application domain.

Keywords:

Sensor grid; Semantic web; Mobile sensor network; Secure wireless network; Secure sensors; Trusted sensors;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B6878: Infrared Sensing Research

Eismann, M.T.

(937) 528-8410

Our research focuses on the following:

(1) Hyperspectral Imaging. This area includes both imaging spectrometer instrumentation for remote sensing and signal processing algorithms for material detection, tracking, identification, and characterization. Novel imaging spectrometer designs that achieve excellent spectral resolution, field-of-view, and radiometric sensitivity in the visible through longwave infrared spectral region are being pursued. We are particularly interested in compact longwave infrared spectrometer designs that achieve high throughput and wide field-of-view. Signal processing advances are investigated for low contrast target detection in diverse clutter backgrounds, change detection over large environmental variations, material identification based on radiometric target/background models.

(2) Long Range Air-to-Ground Imaging. This area includes optical hardware and signal processing concepts for greatly enhancing image quality at very long ranges, including both visible and infrared spectral regions. Issues of particular interest include compensation of long path air-to-ground turbulence effects, imaging through distributed scattering media, shortwave infrared imaging technology, resolution enhancement processing, and unconventional imaging techniques such as passive interferometric and sparse aperture imaging to achieve sub-diffraction-limited spatial resolution.

References:

Eismann MT, et al: Applied Optics 47: F27, 2008

Eismann MT, Stocker AD, Nasrabadi NM: Proceedings of the IEEE 97: 1031, 2009

Eismann MT, LeMaster DA: Optical Engineering 52, 046201, 2013

Keywords:

Hyperspectral imaging; Remote sensing; Signal processing; Polarimetric Long range imaging; Spectrometry; Infrared; Multispectral imaging

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B6994: Semiconductor Laser Source Phenomenology and Development

Bedford, R.G.

(937) 528-8853

Applications in active sensors and infrared countermeasures may often be significantly improved by unique sources. We theoretically and experimentally investigate high-brightness semiconductor lasers with unique properties such as broad tunability, mid-wave and long-wave operation, fast modulation, and multi-wavelength operation. Devices such as vertical external cavity surface emitting lasers combine the inordinate semiconductor optical gain with a classic macroscopic laser cavity, which results in a device that can achieve signal spatial-mode operation under many watts of optical output powers approaching in any wavelength achievable by semiconductor lasers. We are interested in longer wavelength semiconductor lasers in uncommon operation regions, such as the 2-4-micron band through interband Type-I and Type-II lasers, large conduction-band offset intersubband lasers. It is essential to understand material systems (such as GaAs- and GaSb-related compounds) to appropriately design a laser cavity. For example, Auger recombination and carrier confinement both become extremely influential at high power and temperatures. Mitigation of these deleterious effects is essential for efficient operation.

Interest areas include material design and development, fabrication, coupled resonator designs, passive mode-locked lasers, spatial temporal waveform generation schemes for semiconductor lasers, as well as nonlinear frequency conversion. Fabrication facilities are available including semiconductor growth, typical microfabrication techniques, electron-beam lithography, as well as numerous metal and dielectric film deposition techniques. A full testing capability suite is available for cryogenic through high-temperature measurements for device operation.

Keywords:

Lasers; Semiconductor; Infrared; High-brightness; Resonator; Unstable beam; Nonlinear;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7059: Electronic Warfare Wideband Digital Receiver Development

Liou, L.L.

(937) 528-8310

Electronic warfare (EW) receiver is a unique receiver that detects unknown radar signals in a real-time situation. EW wideband digital receiver contains a front analog subsystem and a back digital subsystem. Much effort has been done to improve the performance of the front subsystem. The digital subsystem usually includes time-frequency transfer and signal detection encoder. We are interested in the development to achieve an overall EW receiver performance. Several topics are under consideration:

(1) Innovative method to improve sensitivity in single signal detection and dynamic range in two-signal detection. Understanding and effective modeling of the nonlinear effects due to the analog components in the front subsystem is the first step. The efficient algorithm may then be developed to compensate the effect. The algorithm is preferable to be adaptive and in real-time.

(2) There are various filter bank designs to track wideband signals. Are there optimized filter design and encoder algorithm to effectively detect multiple signals simultaneously? Understanding the fundamental limitation such as the time and frequency resolutions, and the current specifications of the target signal is the first step. The ringing (rabbit ear) effect due to the pulse edges may impose performance limitation with filter bank design.

(3) Besides Continuous Wave (CW) and pulsed CW signals, we are also interested in automatic recognition of the modulation signals, Including Binary Phase Shift Key (BPSK) and chirp pulses commonly observed in radar signals.

(4) Multiple-channel receiver testbed is available in our laboratory. Research topics on various issues involved in digital beam forming techniques such as channel imbalance and mitigation, beam pattern formation, direction finding, compressive sensing methodology, time synchronization among multiple platforms, etc., are of interest.

This research effort includes the model development, followed by numerical simulation to prove the feasibility of algorithm. Preferably, the development can be validated by hard/firmware implementation.

Keywords:

Electronic warfare receiver; Nonlinear effects; Direction finding; Automatic modulation recognition; Time synchronization

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7061: Integration of Multicomponent Oxide Materials in Sensor Applications

Leedy, K.D.

(937) 528-8886

Our research focuses on the development of nanocrystalline oxide materials and the incorporation of these oxide materials in sensing devices. Current investigations include ZnO thin films for transistors, impurity doped ZnO thin films for transparent conductors, and advanced ALD films for dielectric and passivation uses.

The research entails device design, fabrication, and testing, as well as optimization and analysis of material microstructural, morphological, and optical properties to achieve enhanced device performance. Oxide material deposition is accomplished using large-area pulsed laser deposition, atomic layer deposition, and sputter deposition facilities in a fully equipped Class 100 device fabrication clean room. Materials characterization capabilities include electron microscopy, ellipsometry, ellipsometry, x-ray diffraction, atomic force microscopy, Hall effect and photoluminescence.

References:

Scott R, Leedy K, Bayraktarolgu B, Look D, and Zhang Y: Journal of Crystal Growth 324: 110, 2011

Bayraktaroglu B, Leedy K, Neidhard R: Proceedings SPIE 7679: 767904, 2010

Key words: Keywords:

Thin film transistor; Pulsed laser deposition; Atomic layer deposition; Zinc oxide; Nanotechnology; Transparent conducting oxide; Optoelectronics

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7062: Distributed Netted Radar Signal Processing

Himed, B.

(937) 528-8124

Research opportunities exist in distributed, netted radar systems for detecting difficult (low cross section, low Doppler) targets embedded in severe clutter backgrounds. A distributed network of radars systems, including multiple input multiple output (MIMO), consists of multiple radar stations netted together through data communication links. Traditional netted radar systems normally comprise several monostatic radar systems, each operating at a different carrier frequency to avoid the interference and detection confusion among the radar stations in the system. As a result, the multiple radar stations in the system are incapable of operating in a bistatic or a multistatic mode. The strong capabilities of bistatic and multistatic radar systems are well known. An improved netted radar system is one that can simultaneously operate in both bistatic and monostatic modes. In this case, all radar stations are assumed to operate at the same carrier frequency and are coordinated and controlled by a coherent, signal-level fusion processing unit. Such a system not only significantly improves radar performance in target search, tracking, and recognition, but also effectively addresses emerging radar challenges. However, many fundamental challenges exist and need to be addressed. We seek novel methods of waveform design (specifically orthogonal or quasi-orthogonal waveforms) for proper radar functioning. New and robust adaptive processing techniques capable of operating in both bistatic and multistatic environments are also sought. For airborne and spaceborne applications, the geometry-induced Doppler dispersion significantly degrades the performance of adaptive processing techniques such as Space-Time Adaptive Processing (STAP). Multistatic clutter characterization techniques are also desired for better understanding of the impact of clutter on detection performance in these environments. Finally, depending on whether all data is sent to the fusion processing unit for detection purposes (centralized processing), or individual detections made at the sensor level are sent to the fusion center (decentralized processing), new signal processing techniques are desired that cohere signals across multiple distributed radar apertures.

References

Fishler E, et al: IEEE Transactions on Signal Processing 54(3): 823, 2006

Chen CY, Vaidyanathan PP: IEEE Transactions on Signal Processing 56(2): 623, 2008

Keywords:

Distributed sensing; Netted systems; MIMO radar; Waveform design; Centralized processing; Decentralized processing; Bistatic/multistatic STAP; Fusion processing;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7063: Computational Physics for Radar Signal Processing

Sotirelis, P.P.

(937) 528-8569

Research opportunities exist in computational science to design, implement, and test algorithms for enhanced radar designs. Advances in radar signal processing techniques are increasingly using the physical details of the signal environment. We are particularly interested in advancing novel computational electromagnetic algorithms for use on the most challenging radar problems. These challenges include using radio frequency signals for underground sensing as well as for sensing applications throughout the ionosphere.

Reference

Sotirelis P, et al: Proceedings of the IEEE 2009 National: DOI 10.1109/NAECON.2009.5426633, 2009

Keywords:

Computational methods; Physics-based methods; High-performance computing; Computational electromagnetics; Full-wave; Multiphysics;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7107: Computational Electromagnetics and Electronics

Grupen, M.E.

(937) 528-8191

This research involves topics in computational electromagnetics and charge thermodynamics-treated both separately and as a fully coupled system. By itself, the electromagnetics component emphasizes efficient full wave methods for electrically large linear problems. Domain decomposition algorithms applied to full wave discretization schemes are considered along with sufficiently accurate field expansion approximations. Applications for these approaches include optical cavities, waveguides, and nanophotonics. The electronics component focuses on charge transport, particularly in the Fermi gas/drift-diffusion approximation. Accurate representation of hot electron effects and the role of semiconductor bandstructure within this formalism are of interest, as well as the coupling of the classical and quantum confined regions of quantum devices. Applications include quantum well and quantum cascade lasers, detectors, and wide bandgap HFETs. Research interests in such opto- and micro-electronic components extend to high frequency wave effects requiring a fully coupled treatment of vector field electromagnetics and charge dynamics.

Keywords:

Full wave electromagnetics; Charge transport; Drift diffusion; Charge thermodynamics; Semiconductor devices; Quantum well laser; High frequency; Hot electrons; Computational physics;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7108: Photonic Circuits for Quantum Information Processing and Computing

Szep, A.A.

(937) 528-8711

Quantum encoding photons and entanglement are non-classical features unique to interacting quantum systems and are considered to be the fundamental resources that underlie the power of quantum computation, quantum communication, and quantum memory and storage. In general, quantum information processing can be considered as the exploitation of engineered quantum systems. Our goals are to exploit quantum encoded photons and entanglement for the purpose of developing quantum information processing systems with the potential to exceed conventional computing capabilities. Quantum computing systems with unprecedented levels of security and computational capability for select applications promise decreased computation times for complex AF problems such as faster optimization of complex AF C2 systems, ultrahigh-speed signal and image processing, and informational data base searches with a quadratic speed-up.

Current research focuses on the development of photonic integrated circuits that will enable the processing of quantum encoded photons and entangled photon pairs with significantly scaled down dimensions from table top experiements. Generation of single and entangled photons, coupling them into photonic waveguides and devices with polarization maintaining and low optical lossess are of interest.

References:

J.C. F. Matthews, A. Politi, A. Stefanov and J.L. O’Brien, “Manipulation of mulitphoton entanglement in waveguide quantum circuits,” Nature Photonics 3, 346 (2009).Baehr-Jones T, e t al: Optics Express 13(14): 5216, 2005

J. W. Silverstone, D. Bonneau, K. Ohira, N. Suzuki, H. Yoshida, N. Iizuka, M. Ezaki, R. H. Hadfield, V. Zwiller, J. G. Rarity, J. L. O'Brien1 and M. G. Thompson, “On-chip quantum interference between two silicon waveguide sources,” arxiv:1304.1490

Keywords:

Integrated photonic circuits; Quantum Information Processing, Quantum Computing, Entangled Photons, Single Photons

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7313: Waveform Agile Radar Processing (WARP)

Rangaswamy, M.

(937) 528-8567

Radar systems transmit an electromagnetic signal into a volume of space containing both objects of interest (targets) and objects not of interest (clutter). The signal reflects from both kinds of objects and these reflections are received by the radar along with signals produced by other sources (interference). The radar must then separate the target returns from the clutter and interference. There are currently effective techniques for adaptively suppressing clutter and interference at the receiver. Salient examples include constant false alarm rate (CFAR) detectors, adaptive antenna beam forming techniques, and space-time adaptive processing (STAP). In theory, clutter and interference suppression could be enhanced if the transmit signal was tailored to the target/clutter/interference environment. However, despite potentially significant performance gains, this kind of transmit adaptivity has not yet become a mature technology. This is principally due to the insufficient computing power and limited RF waveform generation hardware that have rendered adaptive transmit techniques impractical to implement. However, the coupling of Moore’s Law with recent advances in arbitrary waveform generation has dramatically improved the prospects of transmit adaptivity as a viable technology. We say that a system is "transmit adaptive" if it is capable of altering its transmit waveform in response to knowledge about its environment. By "environment" we mean those elements that affect system performance, such as targets, clutter, and radio frequency interference (RFI). Knowledge of the environment could be acquired a priori, estimated online, or both. There are three main reasons to investigate transmit adaptivity in radar systems: (1) performance improvement, (2) resource management, and (3) novel missions. The first reason involves improving performance subject to constraints on the transmit waveform (e.g., peak power, nice autocorrelation); the remaining two reasons focus on maintaining a minimum level of performance while either minimizing resources or performing multiple functions. For example, a transmit-adaptive system might be able to compute a transmit waveform that maximizes the probability of detection in a given RFI environment (Reason 1). Such a system might also be able to maintain the probability of detection at a desired level while using a minimal amount of transmitted power and bandwidth (Reason 2). Efficient spectrum usage afforded by such a system would provide an immense benefit in a spectrally congested environment. Ideally, an ATx system would also be capable of performing two missions simultaneously--e.g., spotlight synthetic aperture radar (SAR) and digital communications--while maintaining a minimum level of performance for each function (Reason 3). The multifunction capability afforded by WARP would be of considerable benefit in realizing one or more attributes of the Layered Sensing paradigm. Research opportunities exist in every aspect of waveform design and optimization. This includes theoretical design of waveforms, optimization algorithms, and efficient computation. Transition opportunities to investigate practical aspects of implementation and proof of concept demonstrations are available through other laboratory resources.

Keywords:

Waveform agile radar; Transmit-adaptive radar; Waveform design; Waveform optimization; Simultaneous multifunctional operation;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7326: Ultrasensitive Receiver Architectures

Cerny, C.L.

(937) 528-8248

Comprehending the physics-based relationship between a receiver noise floor and sensitivity, parameters such as temperature and bandwidth should offer a multidimensional representation of signal to noise (SNR) dynamic range, and in the case of complex signals of interest, instantaneous dynamic range (IDR). This is often defined as the measurement of a weak signal in the presence of a strong one or as a signal buried far below a dense radio frequency (RF) interference background. Innovations in receiver architectures will be required as well as novel methods for characterizing signals as a function of frequency separation. The design of experiments using physical modeling and simulation tools is desired in developing the RF receiver architectures and appropriate statistical analysis. The formulation of RF laboratory experiments for prototyping of ultrasensitive receiver subsystems integrates with beam-forming antenna/aperture assemblies for future defense applications. Recently completed research has revealed opportunities to develop nontraditional RF receiver architectures, which bridge quantum physics and RF technologies as a multidisciplinary area to address fundamental limitations (e.g., sampling jitter, thermal noise, Nyquist/Shannon theorem limitations) to more efficiently convert a signal from the RF to an encoded digital format. Our long-term research goal is to enable an RF receiver capable of a sequential search and analysis modes under dense/complex signal conditions enable revolutionary sensor payloads.

Keywords:

Digital receivers; Research test and evaluation; Tunable RF components; Applied physics; Non-uniform signal sampling; Statistic/stochastic method;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7367: Computational Methods for Antenna Designs

D'Angelo, J.

(937) 528-8358

This opportunity involves the application of advanced numerical methods for computational electromagnetics towards the modeling of antenna systems. Methods of interest include finite element tearing and interconnect (both time and frequency domain methods), time domain boundary integral methods, and Discrete Galerkin methods. These numerical methods are to be utilized on high performance parallel computers with distributed memory architectures. Applications of interest include antennas on platforms, large phase array antennas, wideband antennas, and conformal antennas. These techniques are to be applied to electrically large systems with the goal of obtaining accurate solutions for multiscale and highly heterogeneous structures. Balancing the burden between user inputs, meshing, and computers to obtain idealized throughput for design studies is also a desired goal.

Keywords:

Computational electromagnetics; Antennas; Parallel computers; Phased arrays; Time domain; Frequency domain; Green’s functions; Fast solvers; Domain decomposition;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7368: Intracavity Laser Dynamics and Diverse Waveform Generation

Usechak, N.G.

(937) 528-8851

This research primarily focuses on manipulating light within laser cavities in order to generate diverse waveforms outside of the laser. Work is currently being conducted experimentally by investigating the mode locking and modulation of multi-section quantum-dot lasers. Computationally we are solving systems of partial differential equations based on traveling-wave models which are able to incorporate not only carrier dynamics but spatial effects in the cavity. We have found that the use of delay differential equations provides a compact model still able to capture some spatial effects and our analytical work has focused on this type of model. Opportunities exist to contribute to one or more of the above listed areas depending on one’s background and interest level.

Keywords:

Quantum-dot lasers; Mode locking; Laser dynamics; Laser theory; Semiconductor lasers; Optical waveform generation; High-speed test and measurement; Nonlinear optics; Integrated photonic development

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7373: Real-Time Multisensor Image Registration of Wide Area Streaming Data

Priddy, K.L.

(937) 528-8583

The primary objective of this research is to perform real-time image processing on wide-area motion imagery to develop and implement algorithms, which support multi-sensor image registration, automated tracking, data compression, and image understanding.

The image processing chain is impacted by image data capture, data rate, image compression, and effects the chain may have on other processing such as tracking and track formation. Tracking of dismounts and vehicles in cluttered urban settings place a strain on the current state-of-the-art in registration, considering that registration needs to be performed in near real time in order to meet system constraints.

One key aspect of the research will be to find a transformation that matches two or more input images to a reference image taken at different times, from different sensors types, and/or from different aspect angles. A transformation must be found so that the points in one image can be related to the corresponding pixels in the other image.

Many military systems which evaluate images require the registration of images, or a closely related operation, as an intermediate step. Image registration is often necessary for the following problems: integrating information taken from different sensors, finding changes in images taken at different times under different conditions, inferring three-dimensional information from images in which either the sensor or the targets in the scene have moved, and for object recognition. In many military applications, the images need to be aligned with one another so that differences can be detected. An example application arises when the geospatial location of the pixels in the reference image may be known making it possible to geo-locate objects or targets in the input images (that are not found in the reference image) in geospatial coordinates. Other examples of military systems where image registration is a significant component include matching a target with a real-time image of a scene for target recognition and matching stereo images to recover shape for autonomous navigation.

Over the years, a broad range of techniques have been developed for various types of data and problems. These techniques have been studied for military applications, resulting in a large body of research. Image registration methods can be viewed as different combinations of the following four components: features space, transformation space, similarity metrics, and search strategies.

The goal of our research is to gather knowledge about the characteristics of each type of algorithm to affect the choice of feature space, search space, similarity measure, and search strategy, which will make up the final technique. We wish to understand the merits and relationships between the wide varieties of existing techniques to assist in the selection of the most suitable technique for a specific problem. We also wish to develop methods that work well with different sensor types such as synthetic aperture radar and infrared sensors as registration of images under differing phenomenology is the way military systems are moving in the near future.

Keywords:

Wide are motion imagery; Optimal feature selection; Change detection; Real-time image registration; Similarity metrics; Pixelpedia; Exquisite geo-registration; Automated tracking; Multisensor registration;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7518: Printed Devices in Photonics and Electronics

Bartsch, C.M.

(937) 528-8854

This research focuses on utilizing novel fabrication techniques, including inkjet printing, nanoimprint lithography, and aerosol jet printing, and exploring the novel material space (in both substrates and inks) that these techniques open up, to fabricate devices with improved performance over current state-of-the-art. The novel materials that can be used with these techniques do not all withstand traditional fabrication methods (for example, photoresists will attack many of these materials). However, these non-traditional materials can provide added functionality to devices as well as the ability to fabricate devices using non-rigid substrates. Potential materials include but are not limited to oxides, graphene, CNTs, organic polymers, and nanoparticles. In-house research involves device modeling, design, fabrication, testing, and comparing the performance of printed devices with those fabricated using more traditional techniques.

Keywords:

Electronics; Photonics; InkJet Printing; Aerosol Printing; Optoelectronics; Nanoimprint lithography; Device Modeling; Printed Electronics

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7606 : Geo-Registration of Video and Imagery Data

Taylor, C.N.

(937) 528-8184

A desired output of most military sensor systems is the location of the object being observed. Computing an accurate geo-location (location in world-based coordinates) of every object observed in an image or video is a significant and well-researched problem. Traditional approaches have focused on either obtaining a geo-location estimate from ancillary data to the camera (such as a combined GPS/inertial system) or on registering the collected data to pre-existing geo-registered data. We are seeking novel approaches to improve the accuracy of either of these two approaches (in terms of both usability and accuracy), or methods of combining the two approaches to achieve more accurate and reliable geo-registration. Research in enabling geo-registration with a limited amount of ancillary data (i.e., a GPS-denied environment) is also of interest.

References

Barber DB, et al: Journal of Intelligent and Robotic Systems 46: 361,

2006

Mirzaei F, Roumeliotis S: IEEE Transactions on Robotics 24(5): 2008

Keywords:

Video processing; Geo-registration; Data fusion

Eligibility

Citizenship: Open to U.S. citizens and permanent residents

Level: Open to Regular and Senior applicants

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7634 : Dual-System Based Formalism for Data to Decisions

Rogers, S.K.

(937) 528-8525

AFRL requires innovative approaches to the problem of developing robust subjective representations of sensory data to apply to many Data to Decisions (D2D) problems. Systems that rely on creating an objective representation of the world are prone to fragility as a result of sensor degradations and dramatic differences in input. These systems are characterized by the attempt to capture attributes of the environment under consideration in a physically accurate representation. In contrast, nature has developed a dual system approach that is able to robustly deal with degradation of sensors and incomplete information. System 1 is fast and reflexive in nature, while System 2 is slow and logical. We seek an implementable mathematical formalism that can model these two systems along with their blending--allowing for learning and decision-making based on a subjective representation that is not tied to maintaining fidelity with physics-based reality. Application areas include D2D domains such as target identification and tracking, sensor management, sensor fusion, cyber, and ISHM. Publication of the resulting work (both on ATRPedia and in public sources) is expected, along with the delivery of any source code developed.

Keywords:

Knowledge representation; ISR; Biologically-inspired; Mathematical formalism; Robust decision making; Subjective representation; Information fusion; Data to decisions

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7635 : Discovery for Difficult Targets

Velten, V.J.

(937) 528-8290

AFRL is interested in discovering new ways to assemble exploitable difficult target signature attributes from the layered-sensing construct--explicitly, from fieldable sensors into products predictive of threat. Targets of interest include dismounts and vehicles (e.g., color, size, shape, and motion) Understanding and organizing target data is the first step toward this goal. The goal of this research is to exploit data from Full Motion Video (FMV), infrared (IR), Laser-Vibrometry (Vibe), LiDAR, and Polarimetric IR to determine what measurable characteristics, or combinations of measurable characteristics, can be used to classify entities in the dataset. For example dismounts can be categorized by demographics including gender, age, and race, and/or classify activities such as running, walking, and digging. Once characteristics are identified that allow for demographic classification, sensed data can be tailored to capture the measurements necessary for exploitation and classification. This effort may include a data collection using fixed sensors from a standoff range (greater than one kilometer). In addition to publications (both on ATRPedia and public sources), delivery of documented source code will be expected.

Keywords:

Feature modeling; Classification; Dismount features; ISR; Video; Feature aided tracking

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.01.B7636: Automated Tracker Tuning

Vasquez, J.R.

(937) 528-8917

Tracking systems operate in a complex environment, connect to multiple sensors and data sources at varying sample rates, handle a diverse set of targets, and all in real time. Typically, adding a new sensor source requires that the tracking engine needs to be tuned to adjust to the characteristics (measurement types including kinematic and feature/classification/identification information, false alarms and clutter, revisit rate, accuracy, biases) on the new measurements. Additionally, the tracking algorithms have many parameters that impact the overall performance, such as association gates and detection thresholds, maximum prediction times before preventing associations, and track initiation and termination policies.

The goal of this effort is to develop algorithms and provide an architecture that allows automated trackers to adapt to the implicit information that is contained in the input data streams by selecting appropriate algorithms and tuning these algorithms in order to produce a complete and accurate picture of the battlespace. At a higher level, the operator (not assumed to be a tracking expert), would simply designate either truth or good/bad tracks as training samples for use in automatically tuning the tracker. Initial focus will be on image-based sensors (FMV or WAMI), but with extensibility to other sensor modes (e.g., radar). Sensor data will include motion video in the following modes: color (VIS) and infrared (IR). In addition to publications (both on ATRPedia and public sources), delivery of documented source code will be expected.

Keywords:

Target tracking; automated tuning

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.02.B0220: Advanced Antenna Technology

Tomasic, B.

(937) 528-8962

Research opportunities exist in the area of high-gain and multibeam antennas to support Air Force air- and spaceborne radar systems. We are particularly interested in wideband (>1 octave) and multiband systems, and in developing both new antenna designs and new efficient analysis methods. This applies to directly radiating planar and conformal arrays, as well as array-fed reflector and lens configurations, which offer the potential for an electrically scanned, high-gain beam at low cost.

Other topics of interest include wide-scan wideband planar arrays, arrays for hemispherical coverage, low-profile UHF/VHF arrays on conformal platforms, planar and conformal frequency selective surfaces, efficient electrically small antennas, and applications of metamaterials in novel antenna and lens designs.

A final topic centers on computational electromagnetics for electrically large bodies. We need to improve both frequency and time domain methods, which eventually will permit us to numerically analyze large finite planar and conformal arrays, including mutual coupling and edge effects on large complex platforms, possibly of exotic nonconducting materials including metamaterials.

References

Josefsson L, Persson P: Conformal Array Antenna Theory and Design. Hoboken: John Wiley and Sons, 2006

Bhattacharyya AK: Phased Array Antennas. Hoboken: John Wiley and Sons, 2006

Keywords:

Electronically scanned antennas; Computational electromagnetics; Conformal arrays; Metamaterials;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.02.B0229: Plasmonic and Metamaterial Enhancements for Multispectral Sensing

Derov, J.S.

(937) 528-8985

Our interests include electro-optic, magneto-optic devices, components, sensors and focal plane arrays operating in the near infrared to the millimeter wave spectrum. Our current research focuses on improved signal detection, polarization control, or other enhancement to photodetectors and focal plane arrays operating in the mid-wave to long-wave infrared with specific interest in multispectral sensing. For example, we are studying the use of metamaterials and plasmonics to enhance the performance of quantum dot photoconductors and focal plane arrays for multispectral sensing. We are using the metamaterial and plasmonics enhancements to reduce the background radiation and increase the selectivity of the photodetectors and focal plane arrays. The work involves experimental investigation as well as modeling of the photodetectors and focal plane arrays. Our facilities include high-end workstations and personal computers, design and characterization capability in the near to long wave infrared. Our characterization capability includes a mid to long wave FTIR, a femtosecond laser tunable from 1 to 20 micrometers for spectral response, photocurrent, dark and noise current measurement setups, and a Photoluminescence measurement setup with sample temperature control form 15 to 300 K. There is access to a full microelectronics cleanroom with nanofabrication capability like high resolution electron-beam lithography and nano-imprinting. There is also access to a high performance computing center, and in-house epitaxy and materials synthesis.

Keywords: Quantum Dots, Plasmons, Plasmonics, Metamaterials, and Spatial Dispersion

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.02.B4946: Electromagnetic and Optical Wave Interaction with Comlex and Periodic Media

Ding, K.H.

(937) 528-8940

Research opportunities exist to develop analytic and numerical methods, in both frequency and/or time domain, for predicting electromagnetic and optical wave propagation and scattering from surfaces and particles of general shape, size, and composition, with random and/or periodic distributions. The statistical nature of the scattering and its dependency on frequency and polarization are significant. Methods for predicting scattering include but are not limited to high-frequency diffraction, surface-integral-equation, volume-integral-equation, transform-iterative, and finite-difference or finite-element techniques.

We emphasize the accurate determination of the complete scattering characteristics of multiwavelength, second-generation canonical shapes (to act as benchmark and calibration solutions for general computer codes and bistatic cross-section measurements) and the diffraction at all angles of incidence and observation from antennas and scatterers. An additional interest is the relationship between the statistical nature of the scatterer and the properties of the scattered field. To complement the theoretical effort, we are developing both near- and far-field techniques to measure the radiation and scattering characteristics of arbitrary antennas and scatterers.

Keywords:

Scattering; Monostatic/bistatic; Polarization; Near/far field; Integral equation; Terrain scattering; Remote sensing; Multiwavelength; Electromagnetics

Eligibility

Citizenship: Open to U.S. citizens and permanent residents

Level: Open to Regular and Senior applicants

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.02.B5355: Integration of Knowledge and Sensor Data for Intelligent Actions

Perlovsky, L.I.

(937) 528-8939

Research opportunities exist in the area of advanced methods for integrating knowledge and data coming from a variety of sources and sensors with the goal of developing intelligent systems capable of extracting actionable information from data and knowledge. Sensor development and data extraction is only one part of enabling the decision support processes. Discovery and disambiguation of the system of interacting agents coordinated within the set of goals is the essence of information construction required for successful decision-making. Between data and actions there are processes of information extraction based on knowledge. Networks of knowledge, interwoven with intentional systems of goal-oriented agents, ought to account for the available options in decision-making based on data, knowledge, phenomenology, and computational processes.

Knowledge includes physical models of sensors, wave propagation and scattering, statistical models of object properties, dynamical models of motion, linguistic text models, semiotic models of meaning, and cultural models of human behavior in a society of interest. Corresponding to the available knowledge, the models might be detailed or approximate, reflecting precisely known physical laws or uncertain intuitions about undiscovered phenomena or human nature. The integrated functioning of an intelligent system is not a one-time deal but a continuous loop of operations in which sensors and data collection are directed based on the current-moment results; models and actions are continuously refined.

The relevant systems have substantial affinity with the known mechanisms of brain and intelligence of living creatures. Whereas, the past algorithms combining knowledge and data often encountered prohibitive combinatorial complexity, the mind can do it. The mind avoids combinatorial complexity by combining conceptual understanding with emotional evaluation. We hope to develop algorithms utilizing non-combinatorial measures of similarity between models and data, resembling affective-emotional capabilities of the mind in combination with modeling-conceptual capabilities.

Biology suggests that intelligent systems are evolving systems. Evolution is a desirable property of the AF systems, so that they improve with experience, rather than become obsolete. Genetic evolution inspired the development of genetic algorithms. Other evolutionary mechanisms suggested by cultural evolution operate faster than genetics. We are interested in evolving network-centric sensory systems inspired by biological evolution of communication and language systems.

Keywords:

Integrated systems; Intelligent agents; Evolution; Evolving systems; Similarity measures; Combinatorial complexity; Affective computation; Emotional computation; Conceptual computation; Models of mind; Semiotic models;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.02.B5790: Phenomenology-Based Adaptive Radar Signal Processing

Rangaswamy, M.

(937) 528-8567

Research opportunities exist in physics and phenomenology-based adaptive signal processing methods for enhanced radar target detection and estimation. Classical adaptive signal processing methods for radar rely on the formation and inversion of a sample covariance matrix. However, nonstationary reflectivity properties of the scanned areas, dense target environments, and strong clutter discretes tend to introduce heterogeneities in the training data for covariance estimation. These tend to have a deleterious impact on detection and false alarm performance. Furthermore, as the dimensionality of the problem increases, the training data support for forming the covariance matrix and the computational cost of the matrix inversion are prohibitively high. To address these issues we seek to exploit a priori information from the scattering physics or phenomenology underlying a given scenario. For example, in many instances clutter can be viewed as the resultant of the scattered power from a small number of strong interference sources, thus rendering it low rank. This information can then be advantageously used to reduce the training data support and computational cost of the resulting adaptive processing algorithm. The problem of target detection is further complicated by the presence of a large number of nuisance parameters. These effects are exacerbated by systems and environmental considerations pertaining to the operational scenario. We seek novel approaches based on either a priori knowledge of the clutter scenario or on principles of invariance for this problem with a goal to maintain a constant false alarm rate and achieve robust target detection performance. Development and performance analysis of MIMO radar signal processing algorithms for the above described scenarios is of particular interest.

Keywords:

Adaptive radar signal processing; Physics-based methods; Constant false alarm rate; Sample support; Invariance; Robust performance; Knowledge-based methods

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.02.B6821: Advanced Concepts for Remote Sensing and Imaging Systems

Khoury, J.A.

(937) 528-8990

The goal of the program is to develop a new multispectral Laser Radar (LADAR) system with associated Adaptive Optics and optical components, which combines both time-of-flight and heterodyne detection. Developing real-time image fusion algorithms and implementing them using DSP and FPGA will be employed to improve the spatial-range resolution, to enhance the field-of-view, and to combine images with different spectral signatures. The acquired images suffer from sinusoidal scan distortion for which a diffractive/refractive element will be developed for optical linearization. Correction of the sinusoidal scan distortion by algorithm development and video implementation on DSP and FPGA platforms are also in this research effort.

THz LADAR systems can be used for military remote sensing, spectroscopic identification of explosives or chemicals, battlefield medical diagnosis, and homeland security. In this project, the goal is to develop a compact THz laser consisting of a coupling between an optical amplifier and a plasmonic amplifier, as part of the LADAR system. Plasmonic and metamaterial devices in particular for THz emission are an essential part of this effort. Dynamic range compressing/expanding, known as companding, is a well-established principle for recovering signals embedded in high noise. We have already introduced dynamic range compression, accompanied by conventional image restoration, which is useful in recovering images embedded in a high-noise environment for Adaptive Optics and Pattern Recognition systems. This dynamic range compression deconvolution technique will be implemented in a variety of forms: (1) a μm-law/A-law telecommunication encoder on DSP and/or FPGA platforms, (2) nonlinear two-beam coupling in photorefractive real-time holographic media, and (3) multispectral optically/electrically addressed MEMS deformable mirror devices.

We will investigate the design of a multispectral, all-optically driven mirror/focal plane array that can be modified to improve several different Air Force sensor systems. The device will consist of multispectral photosensor arrays with integrated pixel-level, MEMS deformable mirror devices. New detectors with dual-band capability, with response in the visible/IR, visible/UV or UV/IR will be studied.

Keywords:

Plasmonics; LADAR; MEMS; Optoelectronics; DSP; Adaptive optics; Diffractive optics; Processing; Pattern recognition, Metamaterials;

.

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.02.B7397: Sensors Aboard Hypersonic Vehicles

Mudaliar, S.

(937) 528-8948

Hypersonic flights lead to high temperature flows, air dissociation, and cumulative heating of air-frames. Consequently the performance of all on-board sensor systems such as GPS, telemetry, communication, command and control, radar, ladar, and electro-optical sensors are all adversely affected to varying degrees by the hypersonic environment. Further, the dynamic range of parameters that characterize the environment is quite large and is strongly influenced by many factors including altitude, velocity, duration of flight, geometry of the vehicle, airframe, and heat-shield material. For instance, the electron density can vary by several orders during the course of a trajectory. Hence, sensor systems encounter a variety of situations. Some of the issues encountered include signal attenuation, communication blackout, signal distortion due to turbulent flow, radiation from heated optical windows, and emission from hot flows. Communication blackout although old is still a problem and is encountered when the signal frequency is well below the plasma frequency. An adaptive sensor system which uses a diagnostic tool to sense and adaptively match to the environment will be desirable. Even in the case when the signal is above the plasma frequency the boundary layer flow can be dispersive, inhomogeneous, fluctuating, and lossy. This poses challenges to wideband RF system using conformal arrays. With arrays we also face the problem of mutual coupling and impedance mismatch effects on beam forming. Moreover, the signal transmitted from the vehicle may be sufficiently intense to initiate nonlinear processes in the flow. The rapid maneuvers and high velocity place limitations on the integration time of the processing algorithms of the receivers. Although optical sensors are not similarly affected by hypersonic flow as RF sensors they have their own share of issues. The hot window can radiate at infrared frequencies and the hot flow fields can emit and absorb at optical frequencies thereby seriously affecting the optical and EO/IR sensors on board. Two major problems of concern are beam pointing error and wave front distortions. We are particularly interested in assessing the impact of environment on spectral measurements and imaging. Research opportunities exist in the analyses and mitigation of the above-mentioned issues confronted by sensors aboard hypersonic platforms.

Keywords:

Communication blackout; hypersonic boundary layer turbulence; Diagnostic tools; Adaptive sensors; Nonlinear processes; optical windows

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.02.B7398: Scattering and Propagation in Complex Environment

Mudaliar, S.

(937) 528-8948

Our primary interests are (1) the statistical models for radar environment such as terrain, ocean, hilly region, forest, atmosphere, ionosphere, and urban region; and (2) relation of the statistical properties of the scattered signals with that of the environment model.

Topics of interest include waves in random media (discrete and continuum models), radiative transfer theory and remote sensing, scattering from randomly rough surfaces, polarimetric scattering, inverse scattering and parameter retrieval from measured data, physics-based models for scattering from terrain and ocean, scattering from media with space-time fluctuations, monostatic and bistatic models for radar clutter, combined random media and rough surface scattering, spectral density of scattering from ocean surfaces, scattering and propagation of radar signals through turbulence in atmosphere and ionosphere, and models for subsurface sensing. Most studies in the literature on these topics are on the derivation of the average scattering coefficients or propagation constants. However, we are interested in more detailed statistics such as probability density function and spectral density of the scattered signals. Often the signals will be of wide bandwidth, so we are interested in the characteristics of scattered signals over a wide range of frequencies. We are also interested in studies on the scattering of targets embedded in complex environment and polarimetric techniques for detecting such targets. The targets may be stationary, mobile, or fluctuating. Of particular interest is the location and imaging of targets embedded in a complex environment.

Keywords:

Random media; Rough surfaces; Imaging; Clutter models; Turbulence; Radiative transfer; Sea clutter; Polarimetry;

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.12.B0126: Electro-Optical Devices for Laser Beam Control

Anisimov, I.

(937) 528-8714

Since the invention of the first laser in 1960, lasers have been widely used as reliable sources of coherent optical radiation in many applications such as optical communication, laser detection and ranging (LADAR), spectroscopy, medical surgery etc. Many of these applications require electro-optical devices for laser beam control (beam steering, beam combining, laser tuning, adaptive optics). Steering of laser beams can be accomplished by electro-mechanically controlled gimbaled mirrors or by more advanced techniques such as optical phased arrays (OPA) or micro-mirror micro-electro-mechanical systems (MEMS). Laser beam combining can be done by use of dichroic mirrors or diffractive optical elements (DOE) such as surface relief grating or volume Bragg grating. Depending on the application, wavelength of the laser emission may be anywhere in visible spectrum (0.4-0.7 microns), near infrared (0.8-2.0 microns), mid infrared (3-9 microns), or long infrared (9-12 microns). Since recent developments of quantum cascade lasers (QCL), which can emit in 3-12 microns spectrum, many interesting applications of these lasers became possible including military applications such as infrared countermeasures (IRCM). However, there is a very strong demand for developing new electro-optical laser beam control devices capable of working in mid and long infrared spectrum (3-12 microns), which will enable many future applications of the lasers.

References:

[1] McManamon, P.F. et.al., “A Review of Phased Array Steering for Narrow-Band Electro-Optical Systems”, Proceedings of IEEE, 97(6):1078-1096, 2009.

[2] Andrusyak, O. et.al., “Spectral Combining and Coherent Coupling of Lasers by Volume Bragg Gratings”, IEEE J. of Selected Topics in Quantum Electronics, 15(2):344-352, 2009.

Keywords: Optical Phased Arrays, MEMS, Beam Steering, Beam Combining, Bragg Gratings, Digital Holography, Mid Infrared, Long Infrared, Diffractive Optics

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.12.B1101: Fully Adaptive Radar

Rangaswamy, M.

(937) 528-8567

Research opportunities exist in physics and phenomenology-based adaptive signal processing methods for enhanced radar target detection and estimation, tracking and classification involving closed loop radar operation. The onerous challenges of harsh environments, difficult targets, and a rapidly shrinking electromagnetic spectrum necessitate a systematic treatment for developing closed-loop radar operation. The concept of fully adaptive radar (FAR) seeks to exploit all available degrees-of-freedom on transmit and receive in order to maximize target detection, tracking and classification performance. This area has received increased interest in recent times and builds upon a rich history of prior research. Of key importance is the concept of closed loop radar operation via feedback. Specifically feedback from the receiver and tracker to the transmitter for guiding the next illumination to better concurrently detect, and track targets of interest in computationally demanding and training data starved scenarios is required. A first step is the development of the feedback signal from the receiver and tracker to the transmitter via prescribed metrics such as mean squared error, entropy, or mutual information. The next step is to develop analytical and computer simulation methods for determining the detection, tracking, and classification performance with respect to single and multiple radar waveforms. Furthermore, due the large number of degrees of freedom, the number of unknown nuisance parameters incurs a substantial increase. Consequently the curse of dimensionality prevails. Novel approaches for overcoming this issue are of considerable interest. Concepts of machine learning can be brought to bear in a powerful manner in this context. Relevant performance metrics include the tracking error and computational cost. Extension of this approach to handle distributed and MIMO radar performance must be undertaken. Performance validation for both single and distributed radar needs to be analyzed using simulated and measured data sets.

Keywords:

Fully adaptive radar, closed-loop radar operation, concurrent detection, tracking and classification, feedback control design, performance benchmarking and validation

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.12.B1205: Mid-IR Quantum Optics

Hendrickson, J.

(937) 528-8927

Research opportunities are currently available for theoretical and experimental investigations in mid-IR quantum optical phenomenon. Currently, we are interested in exploiting the large dipole moments of intra-sub-band transitions in quantum well structures to achieve ultrastrong coupling to plasmonic modes via metallic gratings. Such ultrastrong coupling leads to vacuum Rabi splitting values much larger than those currently obtained with traditional photonic based structures. In addition to more standard experimental tools, a unique high brightness frequency comb Fourier transform infrared spectrometer will be available. Further investigations will be performed to study the quantum nature of these devices.

Keywords: Cavity Quantum Electrodynamics, Solid State Quantum Optics, Vacuum Rabi Splitting, Ultrastrong Coupling, Quantum Wells, Plasmonics, Mid-IR

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.13.B0921: Resonance-Based Chemical/Biological Sensors

Wenner, B.

(937) 528-8920

The major objectives of this work are to design and fabricate plasmonic and micro-/nano-resonant structures for optical chemical/biological sensing applications. Examples of such structures may include metallic nanoparticles, nanoantennas, plasmonic metamaterials, or resonant microcavities. Theoretical models and computational simulations will be developed for these structures to describe the electromagnetic behavior as well as chemical/biological sensitivity of these devices. The resulting fabrication techniques and modeling methods will lead to new technology for devices that can be tailored for specific analytes for chemical/biologic detection schemes. The developed methods and designs will also provide the foundation for techniques to develop new biorecognition elements and surface functionalization chemistries that are key to the success of these systems. It is anticipated that the modeling/fabrication/characterization efforts will be iterative towards the development of a highly sensitive microresonator-based biosensing platform that is robust and amenable to multiplexing arrays.

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.14.B0808: Printed Electronics and Photonics

Heckman, E.M.

(937) 528-8855

This research focuses on using novel fabrication techniques such as ink jet and aerosol jet printing and nanoimprint lithography to print electronic and photonic circuit and device elements. Focus will be on novel materials such as polymers, CNTs, graphene, etc. and on flexible substrates. In-house research involves device and material fabrication, characterization and testing of fabricated structures. Current areas of interest are in field effect transistors and mid-wave IR detectors.

References:

Ha, Mingjing, et al., Nano Lett. 13, 954-960 (2013)

Lee, Seoung-Ki, et al., Nano Lett. 12, 3472-3476 (2012).

Keywords:

Printed electronics/photonics, aerosol jet printing, ink jet printing, flexible electronics

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.14.B0809: Micro-Mechanical Oscillators

Usechak, N.G.

(937) 528-8851

This research seeks to push the performance of micro-mechanical oscillators for applications including the generation of microwave signals, diverse waveforms, and entangled photons. We are currently characterizing resonators made out of a novel material which seeks to improve on what has be traditionally demonstrated. Opportunities exist to contribute to theory, experiment, and/or simulations depending on background and interest level.

Keywords:

Micro-Mechanical Oscillators, Laser theory; Semiconductor lasers; High-speed test and measurement; Nonlinear optics; Integrated photonic development

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.14.B0810: Injection-Locked Semiconductor Lasers

Usechak, N.G.

(937) 528-8851

This research focuses on studying the injection locking of quantum-well and quantum-dot semiconductor lasers primarily in order to generate narrow-linewidth tunable microwave signals. Here different topologies as well as more fundamental issues (such as the suppression of amplitude and frequency fluctuations) are of critical interest and currently being investigated. Depending on background and interest level opportunities to contribute to one or more of the different areas we are investigating including theoretical studies, experimental work, and/or numerical simulations exist.

Keywords:

Quantum-dot lasers; Mode locking; Laser dynamics; Laser theory; Semiconductor lasers; High-speed test and measurement; Nonlinear optics; Integrated photonic development

AFRL/RY WRIGHT PATTERSON AF BASE, OHIO

SF.35.14.B0811: Polycrystalline YAG Fiber Characterization

Usechak, N.G.

(937) 528-8851

This research seeks to demonstrate a viable Polycrystalline YAG fiber for use in amplifier and laser applications. Opportunities exist primarily in contributing to the characterization of these fibers but also in improving these AFRL-made fibers and working toward the goal of demonstrating a viable laser source using these fibers.

Keywords:

Novel Fiber Characterization; Laser theory; Nonlinear optics

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.30.04.B7769: Millimeter-Wave Radio Frequency Propagation Modeling and Validation

Christodoulou, C.

(505) 277-6580

The 71-76 GHz and 81-86 GHz bands have the potential to provide ultrahigh bandwidth (gigabit per second [Gbps] data rates) point-to-point communications between a satellite and a ground station. However, one of the most crucial problems in achieving this communication link is the uncertainty of signal attenuation, phase distortion, and depolarization resulting from atmospheric absorption, scintillation, and meteorological effects (e.g., rain fade). High fidelity propagation models must be developed, statistically validated, and correlated to meteorological parameters and climatic regions as was done for the Ka-band in the 1990s to enable the Air Force to accomplish feasibility studies, systems engineering, and availability modeling to support future military satellite system architectures.

The objective of this research is to develop improved models to predict path attenuation, phase distortion, and depolarization, particularly at 71-76 GHz and 81-86 GHz. Key parameters affecting channel propagation must be identified and the functional relationship modeled.

Some of the goals of this research are (1) a model development of key communication channel properties (attenuation, phase distortion, depolarization); (2) identification of key parameters affecting channel properties (absorption, scattering, scintillation, humidity, moisture, hydrometers, rain-rate); and (3) simulations, comparison to current models

We seek applicants with backgrounds in communications theory, EM theory, or physics with understanding of radio wave propagation phenomena.

References:

Lucente M, et al: Proceedings of the IEEE: 2011

Cianca E, et al: Proceedings of the IEEE (99)11: 2011

Keywords:

Millimeter-wave; Propagation; Physics-based modeling; Communication channel properties; Atmospheric absorption; Depolarization; Scattering; Scintillation; E-band;

Eligibility:

Citizenship: Open to U.S. citizens

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B0159: Applications of Infrared Sensor Technology

LeVan, P.D.

(505) 846-9959

Opportunities exist to develop sensors based on new technology infrared (IR) focal plane arrays. The array types include those which image simultaneously in two IR wavebands, those with cut-off wavelengths approaching 14 microns with optimization for very low levels of dark current, and very large format arrays for wide fields of view with small pixel angular subtense. This research includes the identification of unique venues for economical ground- and space-based demonstrations of focal plane array technology, including the formulation of innovative concepts for fore-optics (e.g., spectroscopic, multi-waveband imaging) that exploit the latest IR focal plane array technology advancements. Related endeavors include the calculation of the signal and background photon rates corresponding to the application and to the backgrounds to which the application applies (e.g., ground-based viewing space, space-based viewing space). Emphasis is also placed on the use of commercial off-the-shelf subsystems (e.g., IR focal plane array drive and data acquisition electronics)appropriately tailored to the application, for reduced cost and risk. Finally, demonstration concepts that allow for the collection of target or background phenomenology data in support of customer requirements provide additional relevancy.

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B5111: Data Fusion, Reasoning, Decision-Making, and Verification/Validation Approaches for Autonomous Spacecraft

Erwin, R.S.

(505) 846-9816

The ability of spacecraft to implement high-level reasoning and decision-making approaches is key to achieving several Air Force capability goals for future space systems. Benefits of on-board autonomy for spacecraft include reduced manpower requirements for mission operations, allows greater span of control for human operators and decision makers, and enables spacecraft to accomplish missions and respond to changing conditions that are un-achievable under ground-control due to communication link un-availability or latency. There are a number of technical hurdles that must be overcome before on-board algorithms will be allowed to control flight- and safety-critical functions on operational spacecraft, including analytic guarantees for the embedded control and reasoning systems used in flight software, and the ability to use systematic and rigorous verification and validation techniques that reduce the probability of undesired system behavior due to emergent behavior or implementation errors beyond what can be achieved using brute-force simulation approaches (e.g., Monte-Carlo testing). This topic seeks to develop new approaches for provably correct reasoning and decision-making algorithms (suitable for direct software implementation), the development and application of rigorous approaches for error detection and/or constraint-violating behavior of non-proven algorithms and software, as well as the application of these methodologies to spacecraft autonomy applications of interest. The project will involve cross-disciplinary research in mathematics, systems and control theory, computer science, and software engineering.

Keywords:

space; autonomy; decision; estimation; data fusion; reasoning; verification; validation; uncertainty; correctness;

References:

1. Chien, S., et. al. “Using Autonomy Flight Software to Improve Science Return on Earth Observing One,” AIAA J. Aerospace Computing, Information, and Communication, Vol. 2, pp. 196 – 216, 2005.

2. Brat, G., et. al. “Experimental Evaluation of Verification and Validation Tools on Martian Rover Software,” Formal Methods in System Design, Vol. 25, pp. 167–198, 2004.

3. Wongpiromsarn, T., Topcu, U., and Murray, R. M., “Automatic Synthesis of Robust Embedded Control Software,” AAAI Spring Symposium on Embedded Reasoning (22-24 Mar 2010, Stanford), http://www.cds.caltech.edu/~murray/preprints/wtm10-aaai.pdf (11 August 2010).

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B5112: Control- and Game-Theoretic Approaches for Space-Based Cognitive Radio Communications in Challenged Environments

Pham, K.D.

(505) 846-4823

This topic explores the use of control- and game-theoretic approaches to the problem of the control of the physical-layer and protocol-structures of cognitive radio systems that will operate in challenged and/or adversarial environments. Specifically, we are investigating the formulation of such problems in a hybrid (mixed continuous/discrete state-space) systems framework and the formulation of the problems of acquisition and communications link establishment as well as link maintenance during radio reconfiguration with and without adversarial third-party jamming systems as a stochastic control and/or game problems. Techniques and methodologies for signal detection and classification, hybrid systems estimation and control, as well as control-oriented modeling of cognitive radio systems are of interest. Promising approaches will be evaluated via simulation and experimental application to satellite communication applications of interest.

Keywords:

space; satellite communications; decision; communication; hybrid systems; estimation; game theory; software defined radio; cognitive radio; detection; information theory;

References:

1. Dobre, O. A., Abdi, A., and Su, W. “Survey of Automatic Modulation Classification Techniques: Classical Approaches and New Trends,” IET Commun., 2007, Vol. 1, No. 2, pp. 137–156.

2. Burbank, J. L., Hammons, J. R. Jr., and Jones, S. D. “A Common Lexicon And Design Issues Surrounding Cognitive Radio Networks Operating In The Presence Of Jamming,” Proc. IEEE MILCOM Conf., 2008.

3. Haykin, S. “Cognitive Radio: Brain-Empowered Wireless Communications,” IEEE Journal on Selected Areas in Communications, Vol. 23, No. 2, pp. 201 – 220, 2005

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B5113: Advanced Spacecraft Guidance, Navigation, & Control

Erwin, R.S.

(505) 846-9816

This project seeks to develop new methods, techniques, and algorithms for challenging spacecraft guidance, navigation, and control (GNC) problems. Specifically, new approaches are being developed for (a) autonomous spacecraft relative-motion guidance and navigation approaches for rendezvous & proximity operations missions, (b) advanced attitude estimation & control algorithms for control-moment gyro, reaction wheel, and thruster-actuated spacecraft systems, (c) analysis and development of techniques for networked autonomous spacecraft performing collaborative missions such as geolocation of terrestrial search and rescue beacons or coordinated inspection of proximity spacecraft, and (d) image-based relative navigation and pose/feature extraction algorithms enabling rendezvous and proximity operations missions. Research proposals that address one or more of these topics from a theoretical or experimental point of view are of interest. This research can make use of the experimental facilities at AFRL, including a spherical air bearing attitude control and determination testbed, image-based spacecraft navigation facilities, rendezvous & proximity operations simulation capabilities, and autonomous multi-spacecraft testbeds.

Keywords:

estimation; navigation; guidance; control; spacecraft; satellites; robotics; image processing; networked control; coordinated control; autonomous systems;

References:

Baldwin, M., Erwin, R. S., and Kolmanovsky, I. V., “Robust Controller for Constrained Relative Motion Maneuvering with Disturbance Rejection,” Proc. AIAA Guid., Nav., & Contr. Conf., AIAA 2013-4721, Boston, MA, August 2013.

Hussein, I. I., Sorrentino, F., and Erwin, R. S., “Bayesian Hybrid Estimation of LTI Networked Systems using Finite Set Statistics” Proc. Amer. Contr. Conf., pp. 396 – 401, Washington, D.C., June 2013.

Weiss, A., Baldwin, M., Petersen, C., Erwin, R. S., and Kolmanovsky, I. V. “Spacecraft Constrained Maneuver Planning for Moving Debris Avoidance Using Positively Invariant Constraint Admissible Sets,” Proc. Amer. Contr. Conf., pp. 4809 – 4814, Washington, D.C., June 2013.

Luna, J. M., Abdallah, C. T., and Erwin, R. S., “Delay-dependent Stabilization of a Class of Nonlinear Time-delay Systems with Time-varying State and Input Delays,” Proc. Amer. Contr. Conf., pp. 3925 – 3931, Montreal, Canada, June 2012.

Allgeier, S. E., Erwin, R. S., and Fitz-Coy, N. G., “Velocity Extrema in Spacecraft Formation Flight,” Proc. 22nd AAS/AIAA Space Flight Mechanics Meeting, AAS 12 – 152,pp. 763 – 781,Charleston, SC, January 2012.

Eligibility: Citizenship: Open to U.S. citizens, U. S. Permanent Residents, or Foreign Nationals

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B5409 : Multiscale Modeling Applied to Chalcogenide Alloys in Reconfigurable Electronics

Edwards, A.H.

(505) 853-6042

We have long recognized that chalcogenide materials such as GeTe, Sb2Te3, and As2Te3 undergo very rapid crystalline-amorphous phase transitions when subjected to either laser light or to electrical current. These materials have recently been incorporated into practical commercial products such as the re-writable DVD. There is no cogent explanation for the time scale of this transition (~tens of nanoseconds). We are also interested in the interaction of these materials with materials used in silicon technology. Our research has combined both experimental and theoretical approaches to study them. Opportunities are available to work on the simulation of the phase transitions (both directions), and on inter-diffusion and the concomitant changes in material properties using a hierarchy of techniques that includes density functional theory, classical molecular dynamics, tight-binding molecular dynamics, classical Monte Carlo, and classical continuum methods. There are also opportunities to influence the direction of our work and develop new hybrid algorithms that would couple two or more techniques. Applicants will be able to interact with a strong in-house experimental effort that includes XAFS, SIMS, SEM, TEM, Hall, Seebeck, and thermal diffusivity measurements. Local computational resources include a 46-node Beowulf cluster and access to shared DOD resources.

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B5453: Electronic Transport in Crystalline and Amorphous Chalcogenide

Edwards, A.H.

(505) 853-6042

We have long recognized that chalcogenide materials such as GeTe, Sb2Te3, and As2Te3 undergo very rapid crystalline-amorphous phase transitions when subjected to either laser light or to electrical current. These materials have recently been incorporated into practical commercial products such as the re-writable DVD. There is no cogent explanation for the time scale of this transition (~tens of nanoseconds). We are also interested in the interaction of these materials with materials used in silicon technology. Our research has combined both experimental and theoretical approaches. Opportunities are available to perform experimental studies of electronic transport in these materials. The applicant will be expected to conduct a wide variety of experiments, including measurements of the Seebeck and Hall coefficients, and of thermal diffusivity; design and set up experiments; and collaborate with other, in-house groups working on modeling and theory of the phase transition.

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B6640: Theoretical Studies of Optical Excitation, Quantum Transport, and Ultrafast Carrier-Scattering Dynamics

Huang, D.

(505) 846-5788

Research involves theoretical studies and numerical calculations of optical excitation, quantum transport, strong interaction of light with matters, and ultrafast dynamics of carrier scattering in low-dimensional semiconductor systems such as quantum well, quantum wire, and quantum dots. For optical excitations, the research will focus on many-body effects on absorption, photoluminescence and inelastic-scattering spectra. For quantum transports, the research will center on effects of elastic scattering, inelastic phonon scattering, and electron-electron scattering on conductances and thermo-electric powers of electrons. For strong interaction of light with matters, the research will emphasize the effects of electronic quantum interference and photonic-crystal cavity on nonlinear optics. For ultrafast dynamics of carrier scattering, the research will focus on quantum kinetics, time-resolved optical spectra, and laser damage.

References:

Huang DH, et al: Physical Review B71: 195205, 2005; Huang DH, et al: Physical Review B71: 045204, 2005

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B6879: Advanced Structures and Materials for Space Power Generation

Senft, D.

(505) 846-9340

On-orbit performance of power generation systems is critical to mission success. Coupled with the demands for increased power generation, it is important to develop and investigate advanced technologies capable of meeting these mission requirements. Advances in single crystal multi-junction, thin-film, and nanotechnology based photovoltaics are important to achieving improved on-orbit performance. The current state-of-the-art photovoltaic cells used for space applications are based on the III-V material systems (e.g., GaAs, GaInP). However, innovative and novel material systems and new approaches for photovoltaic materials that are capable of more effectively utilizing the solar spectrum (in terms of required mass, volume, or area per unit power generated) could provide tremendous advantages for space missions. As an example, thin-film a-Si and CIGS solar cells are being developed by multiple organizations to provide power generation for spacecraft. When thin-film solar cells are coupled with innovative solar array structures, revolutionary space power capabilities can be achieved. To effectively use thin-film solar cells in space, accurate on-orbit performance modeling is required. Accurate performance modeling of thin-film solar cells is very challenging because of poorly understood synergistic dependence on various space environmental factors (energetic protons/electrons, thermal, photons, and atomic oxygen). Since only limited synergistic ground testing is feasible, approaches must be developed that maximize ground testing results coupled with limited on-orbit data. Other forms of photovoltaic structures and materials beyond thin-film approaches are also candidates for space application and will be considered under this research topic. We expect to expand the understanding and advance solar technology through innovative research endeavors, as well as to develop an over-arching modeling strategy and to begin model development with the goal of an accurate, comprehensive, on-orbit performance model for solar cells of a variety of materials and structures.

References

Merrill J, Senft DC: JOM 59(12): 26, 2007

Senft DC: Journal of Electronic Materials 34: 571, 2005

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B7278: Advanced Estimation Concepts for Astrodynamics-Based Space Situational Awareness

Jah, M.K.

(505) 853-2629

This topic area focuses on Space Situational Awareness (specifically space object detection, tracking, identification, and characterization [DTIC]).

Proposed approaches in this area must deal with a number of challenges including: sensor detections that are not associated to known space objects; each space object is unique (different) and the differences in object behavior are all due to non-conservative forces and torques which depend on object characteristics (size, shape, materials, orientation).

Effective assessment of object behavior requires characterization. Moreover, sensor tasking is not optimized for data collection based upon object behavior nor data information content. Simply attempting to maximize the number of observations will not lead to successful space situational awareness.

Typically, object detection, tracking, and classification is performed in mutual exclusivity. Interdependencies amongst these are not exploited in a unified framework (e.g. Finite Set Statistics [FISST]). The proposed research must, with emphasis on inference and prediction:

1. Investigate new data/track association/correlation methods for orbit-regime-agnostic multi-sensor/multi-object DTIC for both known and newly-detected objects

2. Develop a framework to better characterize sensor level errors including biases to improve the input to the trajectory and model parameter estimation process

3. Improve nonlinear estimation and the representation of uncertainty to ensure realism in describing space object ambiguity (e.g. physically realistic/representative probability density functions)

Methods that use information theory as a framework/foundation are favored. More specifically (and what follows is of utmost importance), it is desired to receive proposals which cast the trajectory and parameter estimation process as one analogous to communication theory where the space object is considered to be transmitting a message where the message is the minimal set of states/parameters (channels), corrupted by noises and biases, that fully describe and predict observed behavior and support unique object identification and classification. Determining this basis of channels is desired as well as how to maximize the information content of those channels given available multi-sensor data, taking into account the presence of clutter and the fact that the probability of detection is often times less than unity.

References:

• Hussein, I. I., Früh, C., Erwin, R. S., and Jah, M. K. “An AEGIS-FISST Algorithm for Joint Detection, Classification and Tracking,” Proc. AAS Space Flight Mechanics Conference, Kuai, HI, February 2013 (submitted).

• Hussein, I. I., Jah, M. K., and Erwin, R. S., “An AEGIS-FISST Sensor Management Approach for Joint Detection and Tracking in SSA,” Proc. AAS Space Flight Mechanics Conference, Kauai, HI,

• Früh, C. Kelecy T. and Jah, M., (2013). Coupled Orbit-Attitude Dynamics of High Area-to-Mass Ratio (HAMR) Objects: Influence of Solar Radiation Pressure, Shadow Paths and the Visibility in Light Curves. Celestial Mechanics and Dynamical Astronomy (CELE), Accepted (8/20/2013).

• Wetterer, C., Linares, R., Crassidis, J., Kelecy, T., Ziebart, M., Jah, M., P. Cefola., (2013). Refining Space Object Radiation Pressure Modeling with Bidirectional Reflectance Distribution Functions, AIAA Journal of Guidance, Control, and Dynamics, Accepted (6/10/2013).

• Linares, R., Jah, M., Crassidis, J., Leve, F., Kelecy, T., (2012). Astrometric and Photometric Data Fusion for Inactive Space Object Feature Estimation, Journal of the International Academy of Astronautics: Acta Astronautica, Accepted (08/01/12)

• DeMars, K., Jah, M., Schumacher, P., Jr., (2012) Initial Orbit Determination Using Short-arc Angle and Angle-rate Data. IEEE Transactions on Aerospace and Electronic Systems, 48(3):2628–2637, July.

• Kelecy, T., Jah, M., DeMars, K., (2012). Application of a Multiple Hypothesis Filter to Near GEO High Area-to-Mass Ratio Space Objects State Estimation. Journal of the International Academy of Astronautics: Acta Astronautica, Accepted (07/01/12)

• DeMars, K., Bishop, R., Jah, M., (2012). An Entropy-based Approach for Uncertainty Propagation of Non-linear Dynamical Systems. AIAA Journal of Guidance, Control, and Dynamics, Accepted (11/08/12).

• DeMars, K., Jah, M., (2012). A Probabilistic Approach to Initial Orbit Determination via Gaussian Mixture Models. AIAA Journal of Guidance, Control, and Dynamics, Submitted (September).

• “Continuing Kepler’s Quest”; National Research Council (2012).

Keywords:

Data fusion; Kalman filter; Orbit determination; Attitude determination; Space object identification; Multiple hypothesis; Navigation; Guidance and control; Finite Set Statistics; multi-sensor/multi-target tracking

Eligibility:

Citizenship: Open to U.S. citizens and permanent residents

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B7343: Space Structures

Murphey, T.W.

(505) 846-9969

Getting to and operating in space presents unique structural challenges. Structural mass efficiency, thermal response, precision, dimensional stability, packaging, and deployment all play critical roles in determining the performance of spacecraft sensor systems and addressing these needs leads to methods and architectures that are dramatically different from terrestrial systems. Work focuses on research related to structural aspects of spacecraft systems and should be traceable to improvements in systems of interest to the Department of Defense. Traditional applications include radio frequency reflectors, optical mirrors, phased array antennas, solar arrays, solar sails, and instrument booms. Structural aspects of new and emerging architecture are also highly encouraged.

*Keywords:

Space structure; Deployable structure; Space antenna; Mirror; solar array; Solar sail; Dimensional stability; Space sensor; Reflector;

*Eligibility:

Citizenship: Open to U.S. citizens and permanent residents

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B7488: Satellite Guidance, Navigation, and Control Applied to Close-Proximity Missions

Lovell, T.A.

(505) 853-4132

The Air Force has a pressing need to better understand and utilize the dynamics of relative satellite motion (i.e., the motion of one satellite with respect to one or more other satellites) for close-proximity missions. These missions include both cluster/formation missions and rendezvous/proximity operations missions. The former missions typically involve multiple satellites with maneuvering capability and communication links (both with the ground and one another) performing some cooperative task (e.g., remote sensing), whereas the latter missions typically involve a lesser degree of maneuverability, connectivity, and cooperation among the satellites. Areas of relevant research include:

(1) Modeling of Relative Orbit Dynamics. The relative motion between two or more satellites in close proximity can be modeled in unique ways. The governing equations for such motion can account for a variety of physical phenomena and maybe either linear or nonlinear, time-varying, or time-invariant. We are particularly interested in the formulation of relative dynamics in such a way that it can be characterized geometrically (as opposed to using Cartesian coordinates), as well as in ways that lend themselves to the applications below. A separate area involves the analysis of natural revisit opportunities for proximity operations between satellites, using concepts such as synodic period.

(2) Relative Navigation for Satellite Systems. Satellites flying in close proximity have tight navigation requirements that may exceed the state-of-the-art in relative and autonomous navigation. These requirements include accurate estimation of both the position/velocity and attitude of the satellites. Sensing schemes include differential GPS and intersatellite ranging, using vision sensors such as radar and LIDAR. In addition to sensing, the navigation task requires accurate estimation techniques. We are particularly interested in improved filter design that may involve maximum on-board autonomy (i.e., minimum interaction from the ground), faster computation methods, use of new or unique propagation models, the ability to handle a wide variety of observation types from multiple satellites, and/or applicability over a wide range of orbital regimes.

(3) Guidance/Control Algorithms for Relative Satellite Motion. Satellites flying in close proximity have unique control requirements. Guidance algorithms must be designed taking into account both mission requirements/constraints and the natural orbital dynamics of the system. In addition, control of the satellites must often be accomplished in an optimal fashion, where trajectory time and/or fuel expenditure are of concern. The versatility of satellite cluster missions allows for reconfiguration of the satellites to perform different missions or to account for the addition or deletion of members to the cluster. Such reconfiguration will require sophisticated guidance and control algorithms. Ware particularly interested in the development of open- and/or closed-loop control algorithms for relative satellite trajectories and optimization of these trajectories. The former area may involve both centralized and decentralized control, as well as hierarchical control; while the latter area may involve both conventional (e.g., LQR, gradient-based) and modern (e.g., genetic algorithm) optimization schemes. In addition to the close-proximity maneuvering described above, we would also like to study orbit transfer techniques to achieve rendezvous, whether based on conventional methods (e.g., Lambert transfer) or lesser known methods (e.g., hodograph theory).

Keywords:

Orbital mechanics; Astrodynamics; Satellite; Guidance; Navigation; Control

Citizenship: Open to U.S. citizens and permanent residents

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B7620: Electromagnetic (EM) Wave Radiative Transfer through Cloudy Atmospheres and Hyper-Temporal Detection of Forward/Multiply-Scattered Light

Roadcap, J.R.

(505) 853-3711

The Associate will have the opportunity to perform fundamental investigations of EM wave radiative transfer through hazy, cloudy, and precipitating atmospheres and hyper-temporal detection of forward and multiply-scattered light sources through these media. Phenomena include incident EM wave scatter, absorption, and emission by polydisperse particles with non-uniform shapes and complex permittivities, phase function, and polarized wave intensity as functions of scattering angle, molecular spectroscopic absorption, and molecular scatter. Wavelengths of interest span the ultraviolet through infrared and microwave spectral regions and can involve monochromatic or broadband sources. The novel development of hyper-temporal time series analysis methods using advanced digital signal processing and remote-sensing techniques to detect forward, multiply-scattered point source intensities will also be considered. The Associate will be expected to document, interpret, and explain their findings associated with these phenomena.

References

Balanis CA: Advanced Engineering Electromagnetics. New York: John Wiley & Sons, 1018: 2012

Norquist DC, Roadcap JR, et al: Journal of Applied Meteorology and Climatology 47: 1322, 2008

Keywords:

Electromagnetic wave; Radiative transfer; Scattering; Absorption; Emission; Polarization; Refraction; Fourier transform; Digital signal processing; Remote sensing;

Eligibility

Citizenship: Open to U.S. citizens

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B7633: Ionosphere/Magnetosphere Modeling of Wave Propagation or Wave-Particle Interaction

Su, Y-J.C.

(505) 846-7845

This opportunity encourages applicants to develop new methods or adopt existing models to study wave propagation or wave-particle interaction in the ionosphere-magnetosphere system. Research topics range from electromagnetic signals interrupted by ionospheric density irregularities (i.e., scintillation) to wave-particle interaction scattering energetic particles in the inner magnetosphere. Associates will be encouraged to develop their own research efforts making progress toward improved space weather predictions. We anticipate results from this numerical work will be directly driven by, compared to, and/or validated by ground or satellite measurements.

Keywords:

Ionosphere; Magnetosphere; Space weather; Wave propagation; Wave-particle interaction; Model

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.01.B7696: Coronal and Solar Wind Models and the Data Used to Drive and Validate Them

Arge, C.N.

(505) 846-1965

Accurate knowledge of the state of the solar corona and wind is critical for reliably predicting, days in advance, geomagnetic disturbance events. These events are produced by high speed streams emerging from coronal holes and Corona Mass Ejections (CMEs), which are large eruptions of solar plasma and field. We seek applicants who are interested in working with coronal and solar wind models and/or the input data used to drive them. The modeling side of this work will involve using simple physics and empirical based models, or depending on experience and interest, advanced numerical models such as magnetohydrodynamic (MHD) codes. The data aspect of this effort involves working with a variety of ground- and space-based solar disk observations, as well as in-situ data from multiple spacecraft. These data are used to both validate and/or drive the models.

References:

Arge, C. N., Solar Wind 13, AIP Conf. Series, V 1539, 2013

Lee, C. O. et al., Solar Physics, DOI 10.1007/s11207-012-9980-1, 2012

McGregor SL, et al: Journal of Geophysical Research V A03106: 10.1029/2010JA016006, 2011

Keywords:

Solar physics; Corona; Solar wind; Space weather; Space physics; Magnetic fields;

Eligibility

Citizenship: Open to U.S. citizens and permanent residents

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.02.B0180 : Solar-Terrestrial Physics

Kahler, S.

(505) 853-3517

We conduct research on the characterization, understanding, and prediction of the key elements of space environmental disturbances. These include coronal mass ejections, high-speed solar wind streams, solar energetic particle events, and geomagnetic storms. Current research emphasizes particle acceleration and propagation from the Sun to 1 AU, solar and interplanetary sources of transient and recurrent geomagnetic storms, and periodicities (e.g., semiannual, 22 year) in geomagnetic activity. This work is based on various kinds of ground- and space-based data. We welcome proposals on interdisciplinary efforts that cross boundaries of the Sun, solar wind, and magnetosphere.

Keywords:

Solar corona; Solar wind; Solar energetic particle events; Solar storms;

Eligibility: Citizenship: Open to U.S. citizens

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.02.B0183: Plasma Spacecraft Interactions

Cooke, D.L.

(505) 846-6150

We conduct numerous studies of spacecraft-space plasma interactions that include theory, experiment, data analysis, and computer modeling. This opportunity will emphasize computer modeling in conjunction with ongoing space and laboratory experiments. Possible research topics include critical velocity ionization phenomenon; ionization and discharge processes; optical remote sensing; neutral and ionized gas interactions with ambient medium, high-voltage systems; and natural and induced spacecraft charging. We maintain facilities for computing and scientific visualization, as well as a convenient supercomputer access.

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.03.B6818: Solar Physics, Space Weather. Optical Astronomy, Instrumentation

Balasubramaniam, K.S.

(505) 846-5374

Research areas include solar activity, its magnetism and evolution, and its impact on space weather using ground- and space-based measurements. We develop data driven models of eruptive solar activity, use intelligent systems to forecast solar activity, and use space situational awareness to mitigate the impact on DOD systems. Our goals are to (1) design, develop, construct, test, and deploy instrumentation for ground- and space-based measurements of solar activity using high-resolution optical imaging, spectroscopy, and spectropolarimetry; (2) develop spectroscopic radiative transfer; and (3) develop and test physics and numerical-based models of solar activity.

**References

Balasubramaniam KS, Pevtsov AA, Neidig DF: The Astrophysical Journal 658(2): 1372, 2007

Robinson BM, Balasubramaniam KS, Gilmer A: Optical Engineering 45: 3001R, 2006

**Keywords:

Space weather; Solar physics; Optics and instrumentation; Magnetohydrodynamics; Imaging; Spectroscopy; Radiative transfer; Observations; Artificial intelligence;

**Eligibility

Citizenship: Open to U.S. citizens and permanent residents

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.03.B7067: Solar Drivers of Space Weather

Radick, R.R.

(575) 434-7035

This research opportunity relates to solar and heliospheric phenomena that adversely affect DOD systems and operations, including satellites, communication, and navigation. Research topics exist to study many aspects of solar activity and variability, and their stellar analogs with particular emphasis on instrumentation development and data analysis. Solar telescope facilities enabling high spatial, temporal, and spectral resolution observations of the Sun are available on site, as well as access to data from satellites including the Solar Mass Ejection Imager (SMEI).

*Reference:

Radick RR: Astrophysical Journal Supplement Series 171: 260, 2007

*Keywords:

Solar activity; Solar variability; Solar instrumentation; Adaptive optics; Space weather; Coronal mass ejections;

*Eligibility:

Citizenship: Open to U.S. citizens and permanent residents

Level: Open to Regular and Senior applicants

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.04.B0205: Infrared and Visible Detectors

Nathan, V.

(505) 846-4497

We perform theoretical and experimental research on infrared detectors made of HgCdTe, and superlattice (SL) IR detectors made of II-VI and III-V material systems, such as HgTe/CdTe and InAs/InGaSb. We investigate the band structure, absorption coefficient, quantum efficiency, dark current etc of these materials and detectors.�We are currently studying the following topics: p-type doping in HgCdTe, alternate substrates for HgCdTe and SL detectors, methods to decrease dark current and increase uniformity, increase operating temperature etc. There is also interest in Si hybrid visible detectors. Available laboratory equipment include Fourier-transform IR spectroscopy, and all the equipment necessary to fully characterize detector performance from room temperature to cryogenic temperatures. We collaborate with the University of Illinois, North Western University, and Army Research Laboratory.

References:

Yong Chang, Christoph H. Grein,�Sivalingam Sivananthan, M.E. Flatte, V. Nathan, and S. Guha,�"Narrow Gap HgCdTe Absorption�behavior near the Band Edge including Nonparabolicity and the Urbach Tail," Appl. Phys. Lett. 89, 062109�(2006);�

Binh-Minh Nguyen, Darin Hoffman, Pierre-Yves Delaunay, Manijeh Razeghi, and Vaidya Nathan, "Polarity inversion of type II InAs/GaSb superlattice photodiodes," App. Phys. Lett. 91, 103503�(2007);

Andrew Hood, Pierre-Yves Delaunay, Darin Hoffman, Binh-Minh Nguyen, Yajun Wei, Manijeh Razeghi and Vaidya Nathan, "Near bulk-limited R0A of long-wavelength infrared type-II InAs/GaSb superlattice photodiodes with polyimide surface passivation," Appl. Phys. Lett. 90, 233513 (2007).

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.04.B0207: Research and Development in Passive Sensors

Cardimona, D.A.

(505) 846-5807

Research opportunities in the Advanced Detectors Research Group of the Space Vehicles Directorate are extremely varied. Experimental and theoretical research focuses on new detector development in the ultraviolet to mm-wave wavelength range (currently specializing in infrared [IR] and longer); new detector capabilities such as wavelength tunability and polarization discrimination; and detector interactions with external electric, magnetic, and electromagnetic fields. We are currently concentrating on III-V semiconductor multiple quantum well, superlattice, quantum wire, and quantum dot heterostructures. We have begun investigating the possibilities of organic polymers and nanotubes for IR detection. Our main emphasis is on space-based applications of these new detector designs, so we will always be concerned with radiation hardness and high sensitivity in our studies. We mainly investigate single detector pixels, but we are also interested in full focal plane arrays. Our current research interests include (1) optical-spectroscopy studies such as absorption, photoluminescence, light scattering, and ultra-fast pump/probe transient spectra; and (2) quantum-transport studies such as tunneling, drift, diffusion, and field domains. Available characterization equipment include Fourier-transform IR spectroscopy, magneto-transport and magneto-optical, deep level transient spectroscopy, femtosecond laser pump/probe, and all the equipment necessary to fully characterize detector dynamics and performance at cryogenic temperatures. We have extensive collaborations with universities around the country, especially the University of New Mexico, where we can obtain access to MBE machines, clean rooms, SEMs, and AFMs.

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.06.B0170: Plasma Chemistry for Space Applications

Viggiano, A.A.

(505) 853-3399

We study a broad range of plasma chemistry including electron attachment, ion-molecule reactions, dissociative recombination, and mutual neutralization. We specialize in studying difficult species, radicals, and extended temperature ranges. Several fast flow plasma reaction apparatuses are used. The ion-molecule temperature range is 90-1800 K, while for the other plasma processes temperatures up to 1400 K can be studied. Recent successes include measuring the only product distributions for mutual neutralization, electron attachment to fluorocarbon radicals, and the discovery that electrons catalyze mutual neutralization. A recent upgrade has allowed for studies of radicals with electrosprayed ions, which is important for solar fuels research.

The data support a wide variety of AF/DoD applications including the natural ionosphere, hypersonic vehicles, plasmas assisted combustion, high power lasers, conversion of gaseous to liquid fuels, trace gas detection, high energy density materials, and other catalytic processes.

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.07.B0179: Advanced Space-Based Imaging

Lipson, S.J.

(505) 853-3531

We develop and exploit multiple technologies for space-based optical and infrared detection and identification, with an emphasis on advanced imaging sensor payloads. Possible research topics include imagery data analysis, object identification algorithms, signal processing, satellite on-board processing, data compression, time-series analysis, sensor calibration, modeling of atmospheric transmission and compensation, and other topics related to space-based remote sensing, object identification, and payload design. We have facilities for algorithm development, modeling and simulation, and an in-house sensor calibration facility.

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.07.B5380: Space Weather and Effects

Mozer, J.B.

(505) 853-0059

This research opportunity addresses problems related to solar and heliospheric disturbances that affect DOD operations, including satellites, communication, and navigation systems. Research topics exist in the study of solar flares, solar energetic particles, coronals mass ejections, and shocks in the solar wind, with particular emphasis on detection, forecasting, and modeling of impacts on the geospace environment. Solar telescope facilities, including high spatial, temporal, and spectral resolution observations of the Sun are available on site, as well as access to data from satellites, such as AFRL's Solar Mass Ejection Imager (SMEI).

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.07.B5812: Optical Sensing of Ionospheric and Upper Atmospheric Structure and Dynamics

Pedersen, T.R.

(505) 853-3792

Detection of optical emissions from the upper atmosphere is one of the few means of determining ionospheric and upper atmospheric structure and conditions over large regions. We seek to find improved ways to utilize optical emissions as a diagnostic for conditions in the natural and modified ionosphere. Efforts include development of image processing algorithms, optical filtering techniques, instruments and detectors, and techniques for assimilation of optical data into models. Techniques for automated recognition, detection, and tracking of disturbances such as polar cap patches, auroral arcs, or equatorial depletions will improve specification and forecast of ionospheric conditions and effects on systems. Accurate determination of motion, reaction rates, species densities, or energy or current fluxes can provide input and constraints over large regions for assimilative or theoretical models otherwise dependent on small numbers of measurement points. Interest areas include the natural ionosphere at high, middle, and low latitudes, and artificial effects induced by chemical releases, spacecraft maneuvers, particle beams, or radio waves. Data sets may include measurements from either or both ground- and space-based systems, operating at night, or during daylight. We are also interested in data quality control strategies including cloud detection and background light removal, as well as advanced techniques such as tomography or multispectral imaging. Our group maintains a large data base of optical images from locations around the world as well as a large suite of low-light imaging equipment, and also participates in ionospheric modification experiments.

Reference

Ashrafi, M, M. J. Kosch, and F. Honary, Comparison of the characteristic energy of precipitating electrons derived from ground-based and DMSP satellite data, Annales Geophysicae, 23, 135-145SRef-ID: 1432-0576/ag/2005-23-135, 2005;� Gustavsson, B.; Sergienko, T.; Kosch, M. J.; Rietveld, M. T.; Br�ndstr�m, B. U. E.; Leyser, T. B.; Isham, B.; Gallop, P.; Aso, T.; Ejiri, M.; Grydeland, T.; Steen, �.; Lahoz, C.; Kaila, K.; Jussila, J.; Holma, H., The electron energy distribution during HF pumping, a picture painted with all colors, Annales Geophysicae, Volume 23, Issue 5, 2005, pp.1747-1754, 2005; Martinis,C., J.V. Eccles,J. Baumgardner,J. Manzano,and M. Mendillo, Latitude dependence of zonal plasma drifts obtained from dual-site airglow observations, Journal of Geophysical Research (Space Physics), Volume 108, Issue A3, pp. SIA 8-1, CiteID 1129, DOI 10.1029/2002JA009462, 2003

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.07.B5822: Seismic and Infrasound Research for Monitoring Nuclear Explosions

Xie, J.

(505) 846-6051

Underground nuclear explosions generate seismic and infrasound waves. Monitoring underground explosions encompasses a wide range of seismic and acoustic disciplines. The source mechanics must be understood in terms of the amount and type of seismic and infrasound radiation produced-not only by underground nuclear explosions, but also by other sources such as small shallow earthquakes and industrial explosions. The effects of propagation (including attenuation) through the solid Earth or atmospheric medium control the travel time, amplitude, and other characteristics of waves measured at a seismometer or microbarograph. These basic problems control the ability to perform the practical procedures of detection and location of an event, identification of the event as a nuclear explosion or some other type of source, and estimation of the yield if it is an explosion. Methods of tackling the research problem include theoretical investigation of source physics, modeling and simulation of seismograms and microbarograms to better understand both source and propagation processes, and observational studies of seismic and acoustic wave characteristics and Earth/atmosphere models. We are particularly interested in studies of relatively small (magnitude <4) shallow seismic sources and propagation at local (<200 km) and regional (<3,000 km) distances.

Keywords:

Seismic; Seismic sources; Seismic wave propagation; Infrasound; Infrasound sources; Infrasound propagation; Underground nuclear explosions; Nuclear explosion monitoring; Earth models

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.14.B1112: Game-Theoretic Based Decision Support Tools for Persistent Space Threat Interdiction

Pham, K.

(505) 846-4823

Today the US has a tremendous investment in space, especially in military, intelligence, scientific, and commercial sectors. However, one of the most important space vulnerabilities is the lack of persistent situation awareness of the space operational environment to ensure freedom of action. Space can be an important battlefield in modern warfare because intelligence information from space has become extremely vital for strategic decisions. In addition to real-time and hidden information constraints, the presence of adversaries greatly complicates the decision making process. It becomes necessary to perform space defense analysis and mission trade studies. Although pursuit-evasion game theory is relevant to this problem, most results in the existing literature are from the pursuers’ perspective and not applicable. Innovative solutions are sought for (1) proper game models and constructive game training for a generic space defending scenario where multiple denying assets, defending assets, and pursuing assets with either equal or unequal capabilities are assumed with imperfect, sporadic observations and jamming confrontations; (2) possible constructive methods and approximate solution techniques on distributed learning under sparse communications and adverse environments; (3) efficient computational algorithms to determine real-time cooperative strategies for the space assets, neutral objects, and threats in persistent area denial; and (4) assess the performance under technical failure inaccurate measurements and loss of communications. Proposed advances--together with potential deliverables including novel mathematical developments, interaction modeling, performance metrics, advanced engagement concepts, and design principles--set the foundations to enable assured operations of teams of autonomous defense systems to adapt to hostile, nontraditional environments, which capitalize on effective utilization of modeling and analysis of uncertain systems, as well as multilevel, multi group, multi-agent, control and decision analysis.

References:

Shen D, Pham KD, et al: “Pursuit Evasion Orbital Game for Satellite Interception and Collision Avoidance,” SPIE Defense and Security 2011: Sensors and Systems for Space Applications IV, Proceedings of SPIE 8044: Orlando, FL, 2011

Pham KD: “Risk-Averse Based Paradigms for Uncertainty Forecast and Management in Differential Games of Persistent Disruptions and Denials,” Proceedings of American Control Conference: 842, Baltimore, MD, 2010

Keywords:

Active and distributed learning; Modeling of complex systems; Competitive decision making; Adversarial systems; Distributed computation; Multilevel command and control in hostile environment

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.14.B1113: Hierarchical Decision Architectures, Processes, and Cognitive Communications Networking for Large-Scale Open Distributed Systems

Pham, K.

(505) 846-4823

As DOD systems evolve to incorporate heterogeneous space/air/terrestrial systems from across domains to contend with increasingly unpredictable adversaries, demands for rapid response to tactical needs, and high-bandwidth communication-on demand, aggregation of multiple heterogeneous systems creates integration problems for systems engineers and design management. Constituent systems with the simultaneous nature of information flow lack control over all decision variables affecting their objectives, which is what makes integrative design with total cooperation among heterogeneous systems extremely difficult, if not impossible. The emerging paradigm of concurrent engineering and distributed decision making shows promise to alleviate today’s integration and concurrency problems by ushering new forms of concurrent, agile, and distributed decision architectures as well as new developments of multilevel rational action theories. Keys to this paradigm include decision support algorithms; interaction automation for intra- and inter-level interaction; and design protocols for multilevel, multi group, multi-agent collaborative systems to interact in dynamic and uncertain environments, especially in presence of intelligent adversarial hierarchies. Underpinning research advances and technological achievements are required in the following areas: (1) multilevel theoretical developments for rational actions and team composition for complex multilevel phenomena where cooperative solution teams (a.k.a. groups of agents or actors) work together and communicate, non-cooperative solution teams only act on their own self-interests, and one solution team dominates another in a sequential relationship; (2) information networking and data aggregation that address individual rationality, incentive compability, and sequential rationality when teams in hierarchies take a holistic view (i.e., incorporation of micro- and macro-analysis); and (3) affordable open system architectures for autonomous, reactive, and proactive systems to sense, process data, and interact with each other in order to achieve individual and collective objectives.

Research opportunities include but are not limited to the development of innovative theoretical advances and scalable technologies for concurrent engineering; distributed decision architectures, information networking, and intra- and inter-interaction automation that can effectively acknowledge complex interdependencies between various groups and levels as present in future military systems and hierarchies for multitarget state estimation and multisources, multitarget, multi evidential problems to help human operators enhance their understanding and situation awareness in complex, multilevel, dynamic, and uncertain environments and subject to intelligent adversarial hierarchies at all levels. Finally, demonstrations of proof of-concepts are also in need for reduction in timeline and utility tradeoffs for rapid development of collaborative systems through improvements on standardized interfaces and system components interconnection, as well as documentation of operational/system/technical architectures, compressive data aggregation, collective agent behavior modeling, resource scheduling functions, and traceable sets of measures of mission objectives; measure of effectiveness; functionality capabilities; and quantitative technical performance metrics for utility assessment.

References:

Principe JC: Information Theoretic Learning, Information Science and Statistics, Springer-Verlag, 2010

Keywords:

Distributed and robust decision making; Human-machine interaction; Hierarchical planning and management; Micro- and macroanalysis; Intra- and inter interaction; Information networking; Integrative modeling; Multilevel framework; Intelligent adversarial hierarchy; Compressed sensing; Multilevel rational theory; Multitarget state estimation; Multisource, multitarget, multi-evidential problems;

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.14.B1114: Space-based RF Emitter Detection and Localization Using Field Programmable Gate Arrays

Pham, K.

(505) 846-4823

Satellites are more vulnerable today to radio frequency (RF) jammers and high power in space-band transmitters due to availability of information and low-cost RF equipment. In particular, satellite communications are facing increasingly more diverse physical, cyber, and natural threats from terrestrial stationary and/or mobile RF jammers that transmit RF jamming signals in the X/Ku/ /Ka/Q-band satellite communications. Thus, RF emitter detection and mitigation is essential for reliable satellite operations via communications, positioning, navigation, and timing. As an effective proof-of-concept for space-based RF jamming detection and mitigation, this topic seeks to bring system concepts and software-hardware paradigms enabled by reconfigurable field programmable gate arrays (FPGA) of smart antennas, RF emitter detection, and localization computation which are communicating with orbital propagation simulations of a constellation of cubesat sensors running in NASA General Mission Analysis Tools (NASA GMAT) environments on a personal computer through User Data Protocol (UDP)/Internet Protocol (IP).

Responding to this opportunity and its technical challenges, low-cost solutions proposed should leverage from theoretical and practical fronts of geolocation; software defined radios for reconfigurable sampling rates, bandpass filtering, and intermediate frequency selections as required by X/Ku/K/Ka/Q bands, and flexible FPGA for implementation of custom circuits of matrix-vector multiplications and parallelized algorithms. Innovative system concepts and enabling technology capabilities which are supported by advanced theoretical constructs and practical design principles shall include, but are not limited to (i) modeling, simulation, and analysis tools with life cycle cost considerations for low-Earth-orbit (LEO)/medium-Earth-orbit (MEO)/GEO constellations of 5kg, 10cm x 10cm x 30cm cubesats together with multiple variables and parameters on operational areas of responsibility, revisit rates, RF sensing swaths, host carrier with deployment mechanisms required to enter and exit waiting orbits for cubesat node separations; (2) conceptual designs for smart wideband antenna and onboard sweeping frequency receivers to minimize FPGA resource and power requirements; (3) low complex methods to extract X/Ku/K/Ka/Q-band spectrum characteristics, in addition of trade studies among direction-of-arrival (DOA), time-difference-of-arrival (TDOA), and frequency-difference-of-arrival (FDOA) assisted by Earth surface information maps; (4) operational issues of time and frequency synchronization of space-based transceivers; and (5) dynamic cubesat sensor management for effective RF sensing distribution and localization accuracy. Potential deliverables and figures of merits should include a software defined library of smart antenna emulation, smart antenna calibration, RF emitter alignment based on time markings and spectrum signatures as well as closed-loop performance evaluations of RF emitter detection and localization on custom FPGA hardware components and hybrid software-hardware approach.

References:

Wang Z, Pham KD, et al: SPIE Defense and Security 2011: Sensors and Systems for Space Applications IV, Proceedings of SPIE 8044: Orlando, FL, 2011

Wang Z et al: SPIE Defense and Security 2010: Automatic Target Recognition XX; Acquisition, Tracking, Pointing, and Laser Systems Technologies XXIV; and Optical Pattern Recognition XXI, Proceedings of SPIE 7696: Orlando, FL, 2010

Keywords:

Smart antenna arrays; RF sensing swaths; Wideband scanning receiver; Antenna mutual coupling; Phase delay difference; Spectrum extraction; Dynamic sensor management; FPGA; Free space propagation; Highly eccentric orbital sensor constellation; X/Ku/K/Ka/Q -bands; Antenna calibration; RF detection and localization; Earth surface information maps; Cubesat constellation; Deployment mechanisms; Mission designs; Host carrier operations; Waiting orbits; Life cycle cost; System resiliency;

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.14.B1115: Blind and Beacon-Less TDMA Scheduling for Ad-Hoc LEO Satellite Communications

Pham, K.

(505) 846-4823

Future satellite missions require radio frequency (RF) subsystem architectures with low size, weight, and power (SWAP) that can support remotely piloted aircraft (RPA)’s high data rates at the order of Gbps for both uplinks and downlinks. To meet the ever increasing demands of high data rates, the most commonly used technology in RPA communications is often to be dual polarization in conjunction with time division multiple access (TDMA) and a constellation of Low-Earth-Orbiting (LEO) satellites. Currently, the TDMA technique for LEO satellites requires satellite radio beacons (or pilot tones) to perform TDMA scheduling. Any satellite payloads, which require space radio beacon systems, will increase the SWAP requirements. In this opportunity the Air Force is soliciting innovative R&D advances to enable future technology capabilities in the following aspects: (1) revolutionary design principles using TDMA scheduling without space or satellite radio beacons, (2) robust analysis on satellite fingerprints to search for satellite identification and availability, (3) on/off-board TDMA scheduling to efficiently disseminate schedules to RPA platforms, and (4) TDMA scheduling techniques with and without requiring a priori knowledge of satellite locations. The introduction of this emerging capability onto satellite platforms should have minimal impacts on SWAP requirements and require no a-priori knowledge of satellite locations.

References:

Nguyen TM: Plenary Paper, SPIE Defense and Security 2013: Sensors and Systems for Space Applications VI, Proceedings of SPIE, Vol. 8385: Baltimore, MD, 2013

Kwan WC, Sieteng S, Chen M: A Novel Spatial TDMA Scheduler for Concurrent Transmit/Receive Wireless Mesh Networks, 24th IEEE International Conference on Advanced Information Networking and Applications: 2010

Keywords:

Satellite radio beacons; Feature extraction and inference; Satellite fingerprints; Spoofing and jamming; TDMA scheduling; Sparse observations; SWAP

AFRL/RV KIRTLAND AIR FORCE BASE, NM

SF.40.14.B1116: Anti-RF Jamming and High Throughput Terminals for Wideband Global SATCOM

Pham, K.

(505) 846-4823

The satellite communications industry expects the US reliance on beyond-line-of-sight, in-transit communications, and a range of communications from narrow to broadband to drive an ever-increasing demand for secure and resilient communications that will render the current Wideband Global SATCOM (WGS) systems unable to full fill this unprecedented quest. To respond to this new demand, software-based waveforms and new kinds of low-cost communications terminals are needed that are not only operational on top of the existing WGS waveforms (Quadrature Phase-Shift Keying (QPSK) and offset QPSK), but also suitable for cognitive radios in the face of rapidly adapting, cognitive Radio Frequency (RF) jammers.

To meet the technical challenges listed above, innovative system concepts and enabling technology capabilities which are supported by open and modular architectures and secure WGS waveforms are needed. These concepts and capabilities needed include (but not are limited to): (i) wideband global spectrum surveillance for spectral signatures of WGS bandwidth and near real-time situational awareness of unintentional and/or adversarial RF Interferences (RFIs); (ii) low-cost supplement kinds of communications terminals that can take advantage of novel service waveforms to enable the existing WGS waveforms be more bandwidth and power efficient, high symbol rates, and anti-RF jamming capable; and (iii) open and modular system architectures and supporting processes to increase resiliency of wideband satellite operations centers, WGS systems, and wideband spectrum monitoring systems. Potential deliverables together with figures of merits as mentioned in (i) through (iii) should include a software defined library of robust identification algorithms for RFI sources, efficient algorithm optimization tools for the proposed service waveforms against imperfect knowledge of RFI sources as well as low-cost flexible modems implemented on custom field-programmable-gate-array hardware.

References:

1. Space Technology Needs, FY2016 Core Function Master Plan, Compiled by SMC/XRDT, For Official Use Only, March 2013

2. Wideband Global SATCOM, http://en.wikipedia.org/wiki/Wideband_Global_SATCOM_system, Retrieved on September 23, 2013

Keywords:

WGS, QPSK, OPSK, 8-PSK, 16-QAM, service waveforms, wideband global spectrum surveillance, high throughput, bandwidth and power efficiency, symbol rates, anti-RF jamming resiliency, low-cost modem, WGS satellite transponder simulator, open and modular system architectures, RF interferences, Xilinx FPGA Virtex 7, modem processing, size, mass, watt per pound

USAFA COLORADO SPRINGS, CO

SF.04.01.B0208: Advanced Air Breathing Propulsion

Wisniewski, C.F.

(719) 333-9387

The Advanced Propulsion Group at the Air Force Academy Aeronautics Research Center is developing the technology base for the design of future air breathing propulsion systems. Experimental programs are conducted in the Aeronautics Research Center's four jet engine test cells. Currently, the Center's operational and instrumented engines include the J-69 and J-85 turbojet, the F-109 turbofan, the T-63 turboshaft, and a Chevy 454 (internal combustion). Programs include an investigation of the dynamic response of fan and compressor blades (high cycle fatigue). A variety of advanced techniques are used including ultrahigh rate data sampling of temperature, pressure, and velocity inside the jet engine. In addition, efforts are ongoing to develop efficient propulsion systems with low noise signatures for use in small unmanned aerial vehicles. These efforts include experimental and computational investigations of low Reynolds number propellers and ducted fans. Sponsorship of these research programs includes the Air Force Research Laboratory, SOCOM and DARPA.

USAFA COLORADO SPRINGS, CO

SF.04.01.B0209: High-Speed Vehicle Design

Cummings, R.M.

(719) 333-9223

We conduct basic and applied research that is relevant to a variety of national aerospace applications, including trans-atmospheric vehicles, hypersonic cruise missiles, high-speed vehicles powered by air-breathing propulsion systems, and theater missile defense systems. The research programs involve integration of experimental programs conducted in the Tri-Sonic Wind Tunnel (TWT) and Mach 6 Ludwieg Tube and computations using state-of-the-art numerical codes. Various data acquisition techniques are being developed to determine the pressure, temperature, and heat transfer distributions on models placed in the supersonic stream of the TWT and the hypersonic stream of the Ludwieg Tube.

USAFA COLORADO SPRINGS, CO

SF.04.01.B4645: Gas Turbine Blade Flow Studies

Byerley, A.R.

(719) 333-2969

Research opportunities are available to perform experimental and computational investigations of internal and external flows associated with gas turbine engines. The goal is to understand the fluid physics that will lead to improvements in gas turbine component efficiencies, particularly at low Reynolds Number conditions where performance losses have been experienced. Current research involves measuring the presence of boundary layer separation on the suction side of 10x-scale gas turbine blades in a linear cascade wind tunnel using a variety of flow diagnostic techniques including liquid crystal thermography, hot-wire anemometry, surface pressure measurements, wake measurements, and thermal tuft surface flow visualization. We are interested in active and passive flow control techniques for eliminating the boundary layer separation. In addition, research is in progress on the flow and heat transfer within the internal blade passages, which are used for turbine blade cooling. Recently, experimental investigations have been complimented by in-house computational investigations using Fluent and Cobalt60.

USAFA COLORADO SPRINGS, CO

SF.04.01.B4654: Computational Fluid Dynamics Analysis and Code Development Applied to Unsteady Aerodynamics

Cummings, R.M.

(719) 333-9223

This research is comprised of two phases: computational fluid dynamics (CFD) method improvements for unsteady aerodynamics and comparison of CFD simulations with experiments of unsteady aerodynamics. The CFD method improvements are in the areas of high order turbulence modeling such as detached-eddy simulation, pneumatic flow control method implementation, dynamic grid motion implementation to simulate fighter configurations experiencing enhanced maneuverability, and reduced-order modeling. In addition to code enhancements, this project involves providing CFD comparisons with experiments performed in the US Air Force Academy Aeronautics wind/water tunnels to support ongoing research in delta wing flow control, unmanned combat air vehicle dynamic lift, and massively separated flows of fighter configurations.

USAFA COLORADO SPRINGS, CO

SF.04.01.B4657: Wind Tunnel Investigation of Flight Vehicle Performance, Stability, and Control Characteristics

Yechout, T.R.

(719) 333-9089

This research involves investigation of flight vehicle performance, stability, and control characteristics along with problem solving efforts that directly affect the design of current aerospace vehicles. Specifically, our current work includes aerodynamic characterization of the NASA Maraia sample return capsule and development of an optimized drooped leading edge configuration for the A-10 aircraft. Both efforts have been in progress for about three years. The Maraia effort is sponsored by NASA Johnson Space Center in support of the International Space Station. Operations Team. The A-10 effort is sponsored by the A-10 System Program Office Hill Air Force Base. Both efforts are anticipated to continue through 2015.

USAFA COLORADO SPRINGS, CO

SF.04.01.B5429: Robust Flight Control of UAVs

York, G.W.

(719) 333-9193

The Academy Center for Unmanned Aircraft Systems (ACUASR) focuses on enabling technologies for UAS. With our available fleet of fixed wing UAV, we have developed and demonstrated technologies in cooperative autonomous control behaviors, cooperative sensor networks, and robust and reliable communication networks. Current research areas are: 1) UAV autonomy to sense and avoid air obstacles either with shared position information or integrated sensors, 2) embedded software architecture methods that support rapid deployment of new UAS technologies, and 3) cooperative autonomous behaviors to accomplish a variety of UAS missions using multiple UAVs in environments that include denied communication and global positioning system signals. All research will be verified through simulation and flight tests at USAFA.

USAFA COLORADO SPRINGS, CO

SF.04.01.B5492: Closed Loop Flow Control

McLaughlin, T.E.

(719) 333-2613

This research effort investigates the efficacy of closed loop active flow control techniques in controlling flow behavior near aerodynamic bodies. The work takes a combined fluids/controls approach, identifying control approaches appropriate to the particular problem at hand, guided by detailed knowledge of the flow field, obtained through experimental and computational means. The work seeks to control the flow using a low-order model, based on Proper Orthogonal Decomposition (POD) which identifies the most dominant modes. Sensor information is used to estimate the amplitudes of the time-dependent coefficients of the POD modes. Based on this estimation, a closed loop controller commands the actuators that trigger actuators based on surface sensor information. Similar, non-POD methods could also be employed. A closely integrated dual path of experiment and Computational Fluid Dynamics (CFD) methods is in use to make most of the advantages of both tools. The active manipulation of a flow field has been elusive for many decades. Recently, with the surge of new technologies in the areas of sensors, actuators, and real-time data processing, the dawn of the "closed-loop era" is breaking. The various pieces of a closed loop system have been investigated independently, but piecing them together has been achieved in only a limited number of flows. This area of research is multidisciplinary in nature merging the fields of fluid flow, controls, simulations, data processing, and structures. The results of the effort should be a robust, well-validated method of controlling flows where passive and open loop means are ineffective or impractical.

USAFA COLORADO SPRINGS, CO

SF.04.01.B5635: The Physics of the Single Dielectric Barrier Discharge Aerodynamic Plasma Actuator

Enloe, C.L.

(719) 333-2240

Dielectric barrier discharges are a well-established technique for producing a stable plasma at atmospheric pressure. A highly asymmetric single barrier discharge has been shown to have a substantial, beneficial effect on the airflow around aerodynamic surfaces and is a candidate for efficient, no moving parts flow control. However, the morphology of the plasma actuator is not completely known and current explanations for the mechanism of the actuator's coupling of momentum are speculative. With the physics of the actuator not well established, it is impossible to optimize the system for practical applications. We are conducting a comprehensive series of experiments and a parallel series of numerical simulations to describe and predict the spatial and temporal development of the discharge, to parameterize its behavior, and to determine unambiguously the mechanism of momentum coupling to the surrounding air. This effort is applicable to both experimental and theoretical/numerical specialties.

USAFA COLORADO SPRINGS, CO

SF.04.01.B5796: Space Weather Research

Chun, F.K.

(719) 333-2601

The Center for Space Situational Awareness Research (CSSAR) in the Department of Physics at the US Air Force Academy is interested in satellite tracking and characterization. CSSAR is actively working in the areas of (1) non-imaging photometric, spectral, and polarimetric techniques leading to the identification and characterization of unresolved space objects; (2) modeling and simulation to understand the inverse problem associated with characterization of non-resolved space objects; (3) initial orbit determination using metric data from bi-static radar returns and angles-only optical measurements; (4) short-arc precision orbit determination with high-rate optical measurements; and (5) investigation of resolved imaging techniques such as lucky imaging. CSSAR is developing a network of small aperture telescopes that will provide global coverage of the space catalog and the capability to observe satellites simultaneously from multiple telescope locations for data fusion research.

USAFA COLORADO SPRINGS, CO

SF.04.01.B5798: Dynamics of Ionospheric and Mesospheric Optical Emissions

McHarg, M.G.

(719) 333-2460

We are interested in understanding how the dynamics of the mesosphere and ionosphere can be remotely measured using various optical techniques. We use both ground- and space-based observations of these regions, which are difficult study in situ. Our ground-based observations use a variety of high-speed camera and multi-anode photometers to investigate high-speed optical fluctuations associated with the aurora and sprites. Space-based observations of the aurora and airglow use data from the Global Ultra Violet Imager to establish the average energy and energy flux of incoming auroral precipitation, as well as to determine the plasma density in the equatorial ionosphere. We hope to gain a better understanding of the different time and spatial scales, which may be important in the understanding and ability to model the coupled ionosphere, mesosphere system.

USAFA COLORADO SPRINGS, CO

SF.04.02.B0212: Laser Cooling and Nonlinear Optics

Knize, R.J.

(719) 333-4165

We conduct research on laser cooling and trapping of neutral atoms, and on the development and application of nonlinear optical materials. Laser cooling is used to produce cold atoms, which can be confined in a far off resonance optical trap. Current research focuses on producing and trapping cold molecules for frequency standards, and on achieving long atomic coherence times for measurement of small physical phenomena (e.g., an atomic electric dipole moment). We are also examining nonlinear optics of these cold trapped atoms, optical nonlinearities of doped polymers and ion implanted silica, and the use of holography for correction of optical elements.

USAFA COLORADO SPRINGS, CO

SF.04.12.B1121: Design, Synthesis, and Reaction Chemistry of Metallocenes and Organometallic Materials

Balaich, G.J.

(719) 333-6043

The structure of the ligand framework surrounding d and f block metals is a key factor that affects the stoichiometric and catalytic reactivity of organometallic complexes as well as the properties of materials incorporating organometallic subunits. Substituted fulvenes are versatile synthons for this framework and are under investigation in our laboratory in four areas of research emphasis: (1) the synthesis and reactivity of ansa-metallocenes by reductive coupling of substituted fulvenes, (2) the synthesis and reactivity of un-bridged metallocene complexes derived from substituted fulvenes, (3) the synthesis and reactivity of metal fulvene complexes, and (4) the incorporation of or use of substituted fulvenes in the synthesis of polymeric and supramolecular materials with metal bound subunits. Research in any of these areas will include the use of in-house equipment for inert atmosphere work and instrumentation for spectroscopic and other analyses. Laboratory facilities in the Department of Chemistry include a Vacuum Atmospheres dry box, solvent purification system, and several vacuum line systems. Instrumentation for structural characterization is available in the department’s instrumentation facility and includes two NMR spectrometers, a single crystal X-ray diffractometer (Bruker CCD platform system with low temperature accessory), FTIR spectrometers, a CHNS combustion analyzer, thermal analysis instrumentation (TGA-DTA, DSC, and DMA), and a GPC system (PL GPC-220 system with triple+ detector system).

USAFA COLORADO SPRINGS, CO

SF.04.13.B0820: Composites for Advanced Materials

Iacono, S.T.

(719) 333-6005

Our research team focuses on preparing functionalized polymer and hybrid polymer composites directed towards developing next-generation, high-performance materials to meet operational AF and mission partner needs. Active research areas include:

- Fuel repellent fabrics

- High fidelity bio-mimicked surfaces for liquid repellant materials

- Aircraft deicing coatings

- Space durable, antimicrobial components

- Proton exchange membranes (PEMs) for next generation fuel cells

- Used tire recycling

- Organic electronics: optical sensors, light harvesting, photovoltaic

On-going projects include, but not limited to, processable, partially fluorinated poly(aryl ether)s, fluorosiloxane hybrid composites, ionic liquids for heat transfer fluids, chemical/biological detection, and rubber recycling, and extended poly(aromatic)s for organic electronics. Projects encompass organic/polymer synthesis, processing, and characterization. Our continued multi-invested collaborations include industry partners, Department of Energy, Army Criminal Investigation Laboratory, and many technical directorates within the Air Force Research Laboratory. Laboratory research facilities in the Department of Chemistry include a host of modern advanced materials processing and characterization (in addition to the standard suite of small molecule characterization): controlled atmosphere dryboxes, multi-solvent purification system, all hoods equipped with Schlenk lines, two NMR spectrometers (300 and 400 MHz), Gaussian single crystal X-ray diffractometer, thermal analysis instrumentation (DSC, TGA, and DMA), surface characterization (powder XRD, MALDI, AFM, and SEM), UV-Vis/PL, GPC system, and processing equipment (electrosprayer, spin coater, metal vapor deposition, ball mills, and sCO2 extractor).

USAFA COLORADO SPRINGS, CO

SF.04.13.B1130: Advanced Microwave Antennas Using Metamaterials Technology

Musselman, R.L.

(719) 333-4211

Research opportunities include experimental investigations of interaction of microwave electromagnetic radiation, with metamaterials and their use for advanced antenna design. Left-handed matamaterials will be designed that possess both negative permittivity and negative permeability, thus negative index of refraction, also called double negative material. Metamaterials can be used to direct microwave energy with the metamaterial slab focusing the radiation of an antenna just like a lens focuses a light beam in optics. This project intends to apply a novel IR imaging technique to map 3D electromagnetic fields inside of a metamaterial slab. The IR imaging technique will be used to elucidate the fundamental physics behind propagation of electromagnetic waves inside metamaterials of different configurations and to understand the focusing properties of a metamaterial slab attached to an antenna.

USAFA COLORADO SPRINGS, CO

SF.04.13B0821: Mechanistic Basis for Biological Polymer Stability, Electron Transfer and Molecular Sensing in Extreme Environments

Veverka, D.V.

(719) 333-9670

One of the most critical factors in biosensor / MFC technologies is the efficient coupling of the biological material, enzyme or microbe, to the electrical interface. On the organismal level, microbes have been shown to interact with external electrodes or insoluble inorganic metallic compounds through three distinct mechanisms; one indirect and two direct [1]. Indirect interaction is carried out by secreted soluble mediator compounds that shuttle electrons between the cell and the electrode. This is less desirable as electron transfer can obviously be diffusion limited and, moreover, the mediators and microbes are not attached to the electrode and hence are easily lost. In direct transfer mechanisms, conductive proteins form a bridge between the microbe and the electrode. These can either be a complex set of periplasmic and extracellular cytochromes, as in the case of Geobacter sulfurreducens, where electrons are conducted through a series of physically close hemes, or a conductive pilus, formed by some Geobacter, where stacked aromatic rings of amino acids that form the helical structure of the pilin subunits permitting electron transfer through delocalized Π transfer. Since these last two depend upon complex protein structures it is doubtful that these would remain intact under harsh and extreme conditions. Hence, there is a need to isolate electrically active extremophilic organisms in order to understand how they are able to maintain robust electrical connectivity under extreme conditions. This could be through modified versions of what is already known, or perhaps via novel mechanisms. Thus, isolating and characterizing novel electrically active extremophiles could lead to the discovery of robust, and perhaps novel, mechanisms of electrical connectivity. This could be useful in establishing whole cell biosensors and/or MFCs, or, as detailed below, in effectively coupling redox active enzymes with electrodes.

[1] Lovley, D.R. Electromicrobiology. Annu. Rev. Microbiol. 2012. 66:391–409

Laboratory research facilities in the Life Sciences Research Center host a range of modern algae materials processing and characterization in addition to the standard suite of cultivation and analysis capability, to include: A 40 sq ft walk-in Environmental Growth Chamber, 30 cu ft Percival growth chamber, orbital shakers, and an incubator are dedicated for the growth of algae, BioFlo 115 New Brunswick 14L bioreactor for experimentation with carbon dioxide sparging on chemostat cultures, Accuri C6 flow cytometer for algal growth monitoring, two PCR thermal cyclers, Nanodrop, ABI 7900HT real time PCR system and lipid class analysis is performed using an Iatroscan MK6 TLC-FID system. We also have access to a Polaris GC-MS system and additional HPLC and LC-MS systems.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.01.B1213: Adaptive Control for Improved Laser Beam Pointing & Tracking

Carreras, R.A.

(505) 846-2711

Aircraft-based laser tracking systems are subjected to a range of disturbances that originate from the aircraft, the optical train, aero-optics effects, and the dynamics nature of the atmosphere. The existence of these disturbances, coupled with the unknowns associated with the targets of interest, combine to make pointing and tracking with a laser beam tracking system a formidable task. Aircraft platform disturbances are particularly troublesome because system modeling and system identification approaches do not accurately capture a sufficiently true representation of this dynamic plant. The objective of this solicitation is to have research conducted into developing adaptive control approaches to mitigate laser beam pointing and tracking errors generated by these disturbances while maintaining at least the minimum required bandwidth. In addition, it is desired that the application of advanced adaptive control techniques result in the extension of this bandwidth to more desirable values. All developed techniques should be robust to uncertainties in the system models as well as to sensor noise, and be shown to be stable in the sense of Lyaunov. Performance of techniques developed under this solicitation must be tested against current state-of-the-art algorithms to demonstrate their improved performance.

References:

Liu, Yu-Tai and Gibson, J. Steve. “Adaptive control in adaptive optics for directed-energy systems." Optical Engineering (2007): 046601-1 - 13.

Ioannou, Petros and Fidan, Baris. Advances in Design and Control: Adaptive Control Tutorial. SIAM, 2006

Narendra, Kumpati S. and Annaswamy, Anuradha M. Stable Adaptive Systems. New York: Dover Publications, 2005

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.01.B2132: Spectral Coherence Analysis Techniques for Improved Laser Beam Control of Jitter

Carreras, R.A.

(505) 846-2711

Many laser beam control systems are quite complicated and are constructed of many sub-systems. All these different distinctive subsystems can be very well individually characterized. However, the combination of all the different subsystems to form the larger complex beam control system and the coupling of the mechanical disturbances to this larger systems can be very difficult to quantify. This research topics explores the application of advanced Spectral Coherence, Multiple Coherence and Partial Coherence Analysis techniques to accurately identify disturbance sources, perform system and model identification to further mitigate the sources of the disturbance. Complicating the analysis further, the laser beam control system is usually on a mobile platform. The platform can either be a mobile ground platform, an airborne platform or a naval vessel. The addition of the platform dynamics and the unknowns of the complex laser beam control system, contributes to a direct effect of jittering the laser beam on target. Jitter smears the HEL beam on target, reducing its integrated intensity and therefore its target damage capability. This is generically referred as jitter error.

The objective of this solicitation is to have research conducted into developing quantitative, analytical tools using Spectral Coherence, Multiple Coherence and Partial Coherence Analysis approaches to extend resolution techniques in identifying uncertainties from unknown disturbances which in turn create laser jitter errors. In addition, since the application of these advanced analysis techniques will improve the resolution of the disturbances, it is desired that more accurate model identification of the plan would naturally occur. Therefore, knowing an accurate model of the disturbances and an accurate model of the plant would then give the researcher the ability to develop more precise, robust and optimal compensation designs.

References:

Petre Stoica, Randolph Moses, Spectral Analysis of Signals, Peason/Prentice Hall, 2005

Julius S. Bendat, Allan G. Piersol, Random Data, Analysis and Measurement Procedures, Second Edition, Wiley-Interscience1986.

T.T. Georgiou, “An intrinsic metric for power spectral density functions”, IEEE Signal Processing Letters, 14(8): 561-563, August 2007.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.01.B3452: Experimental Investigation of Ultra-short Lasers, Nonlinear Matter Interactions, and Propagation

White, W.M.

(505) 853-4957

Our research involves experimental studies of ultra-short pulse lasers (USPL) capable of producing extremely high peak electric fields; their nonlinear propagation and eventual interaction with different materials. This research is aided by theoretical predictions and numerical simulation of USPL generation, propagation, and eventual interaction with materials. Femtosecond pulses at Terawatt and Petawatt power levels are at the center of our work, including the use of single or multiple pulses to produce filaments. Candidates with demonstrated experience in the field of experimental short pulse laser physics (or applicable associated research) are desired from a variety of fields including, but not limited to: physics, electrical engineering, or optical sciences. Selected applicants should expect to work with USAF staff, collaborating university faculty, and summer students at the graduate and undergraduate level. The goal of this work is to develop and integrate experiments with newly developed theories and to improve the applicability of this resulting research across the optical spectrum.

References:

Rulliere C: Femtosecond Laser Pulses: Principles and Experiments in Advanced Texts in Physics 2nd Edition. Springer, 2004

Couairon A, Mysyrowicz A: Science Direct, Physics Reports 441: 2007

Keywords:

Nonlinear optics; Terawatt laser; Ultra-short pulse lasers; Laser-induced filamentation; Petawatt laser; Femtosecond interaction; Optical system design; Optical Kerr effect; High peak electric fields; Laser-plasma interactions, Laser-material interactions.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.02.B0165: Compact, Portable Pulsed Power

Domonkos, M.T.

(505) 385-7767

Research focuses on technology for compact, portable pulsed power and its applications. This includes capacitor driven and explosive pulsed power driven devices; inductive store-opening switch pulse compression; electro-explosive opening switches (fuses); magnetic flux compression with solid and plasma armatures; various types of plasma switches; diode, plasma, solid liner, and compound loads; and various types of intense radiation sources. Potential applications include intense pulsed radio frequency (RF), x-ray, and neutron sources; directed energy concepts; pumping short wavelength lasers; and spacecraft propulsion. Experimental facilities consist of two laboratory buildings with several capacitor banks ranging from tens of kilojoule; tens of kilovolt to 9 megajoules; tens of megamps with risetime consistent with faster versions of explosive pulsed power; a variety of compact Marx banks; RF shielded enclosures with numerous fast transient digitizer and analog recorders for data acquisition; substantial vacuum and power supply hardware; pulsed current, voltage, and magnetic field diagnostics; rotating mirror and gated microchannel plate tube fast photography; optical, RF, vacuum-ultraviolet, x-ray, gamma, and neutron spectroscopy equipment; and an explosive firing site adjacent to one of the laboratory buildings. There are extensive complementary theoretical/computational abilities and resources in the division, including one-, two-, and three-dimensional radiation magnetohydrodynamic and particle-in-cell codes, which have been developed, and are being further developed to guide and interpret experiments. We are developing parallel versions of these codes, parallel processing, and high-performance computing techniques.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.02.B1122: Theory of High Peak Ultra-short Pulse Laser Propagation and Nonlinear Matter Interaction

White, W.M.

(505) 853-4957

This work involves determining the mathematical and physical nature of high peak intensity laser pulse generation, propagation, and eventual laser-matter interaction. Femtosecond pulses at Terawatt and Petawatt power levels are at the center of our work, including single or multiple pulses at high repetition rates. Our research includes theoretical physics studies coupled with numerical simulation to understand how ultra-short laser pulses propagate and interact with matter. For example, one of our goals is to examine the deterministic and statistical nature of femtosecond laser-induced plasma filaments in air and the resultant propagation process. Proposed work under this topic should focus on applied mathematics and computational development (coupled systems of nonlinear partial differential equations of the nonlinear Schrodinger type); as well as the theoretical physics necessary to describe the process of laser-induced plasma formation and electromagnetic field coupling to plasma filaments. Candidates with demonstrated experience in this field (or applicable associated research) are desired from a variety of fields including, but not limited to: mathematics, applied mathematics, and theoretical physics. Selected applicants should expect to work with USAF staff, collaborating university faculty, and summer students at the graduate and undergraduate level. The goal of this work is to develop and integrate theory and computational model components, and to improve the applicability of this resulting research across the optical spectrum.

References:

W.L. Boyd, Nonlinear Optics, 3rd Edition. Boston: Elsevier Inc, 2008

A.C. Newell and J.V. Moloney, Nonlinear Optics, Westview Press, 2003.

Keywords:

Nonlinear optics; Terawatt laser; Ultra-short pulse lasers; Plasma channels; Laser-induced filamentation; Nonlinear propagation; Petawatt laser; Optical Kerr effect; High peak electric fields; Laser-plasma interactions; Laser-material interactions; Laser simulations.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.02.B1189: Fiber Laser and Beam Combination Research

Dajani, I.

(505) 846-6339

AFRL has ongoing experimental and theoretical research aimed at achieving high brightness high-power fiber lasers. Such research requires detailed experience in laser physics, fiber optics, solid state physics, beam combination, thermal and thermo-optic effects, and nonlinear optical phenomena. Experimental as well as theoretical studies and simulations of physical phenomena and processes relevant to power scaling and innovative beam combining methods proposed for diverse fiber laser systems and aimed at achieving high beam brightness and ultra-high power levels (100 kW and higher) are of great interest. The following are among the potential research areas for fiber laser and beam combination:

Efforts involving methods of generating high-power near diffraction-limited beams in the near-IR or mid-IR regions through rare earth doped or Raman fiber lasers. Detailed investigations of these laser systems including any advantageous or deleterious linear or non-linear processes. Stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS), four-wave mixing (FWM), and modal instabilities (MI) are some of the phenomena that are relevant to high-power fiber lasers. Also of interest are specialty fiber designs that can potentially lead to power scaling including photonic crystal and photonic bandgap fibers. Detailed investigations of novel coherent or spectral beam combination techniques scalable to 100 kW. Novel techniques that can enable robust operation of compact fiber-based high-power phased arrays. The research effort can be theoretical, experimental, or both in the areas discussed above. State of the art experimental and computational facilities are available for this research.

University faculty well-versed in all aspects of laser science, physical and non-linear optics, and optical engineering, are invited to apply.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.02.B3915: High Power Microwave Source Research

Hendricks, K.J.

(505) 853-3915

Vacuum electronic sources over a wide range of wavelengths at high power density represent a current area of research interest for the Air Force Research Laboratory. These sources span the range from 1GHz L-band sources at gigawatts of power to 90GHz W-band sources at megawatts of power to THz sources at hundreds of watts of power. Each of these technology areas shares the extreme difficulties of coping with large power densities that stress current materials technology as well as the physical understanding of basic physics phenomenology of the sources operation. As such, this research area requires a strong coupling between experimental work, theory, and modeling and simulation.

This research area consists of the following foci of interest: 1) Novel vacuum electronic sources, operating in the range from 1 GHz to the THz regime; 2) New technologies, such as nonlinear transmission lines, that provide wide ranges of frequency tunability and agility; 3) Supporting technologies to enable these devices. This area comprises technologies such as new cold cathode materials, new electron collectors, new vacuum window technologies, new vacuum pumping technologies, and new pulsed power materials and topologies; 4) Adoption of advanced materials modeling to investigate new materials for all aspects of these sources. Efforts to improve each of these areas, with strong coupling between theory, experiment, and modeling, comprise a vital aspect of these research goals.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.02.B4707: High Performance Compact Pulsed Power Components

Heidger, S.L.

(505) 853-4707

Compact, reliable pulsed power for high power microwave (HPM) generation is of particular interest to the Air Force. These generators require either high peak power at relative low duty cycle and high field strengths, or high average power at high duty cycle and lower field strengths. Development of each specific HPM generator has its own unique challenges. However, all have in common problems associated with the exposure of various devices materials to extreme electromagnetic, thermal and mechanical environments. This topic focuses on studying and utilizing new materials - dielectrics, insulators, metals and interface coatings in the design of components of the compact pulsed power systems such as modulators, capacitors, switches and anodes for cold cathode sources. Fundamental studies on compact pulsed power generation and innovative material and engineering techniques are needed to reduce the size and mass of these pulsed power components. An effective research effort in any of these component systems will require a combination of theory, experiment and modeling.

An example of a research area that is within the scope of this topic is high energy density pulsed power capacitors. The energy density of pulsed power systems for high power microwave (HPM) systems remains limited by the storage capabilities of the dielectric sub-system, which may consist of either capacitors or solid dielectric lines. Gigawatt-class HPM systems generally operate from megavolts to hundreds of kilovolts with pulse durations no more than several hundred nanoseconds long. The state-of-the-art for commercially available pulsed power capacitors approaches 2 J/cc. However, in practice, repetition rate (as high as 100 pps), discharge rate <0.1 microseconds and lifetime requirements for HPM systems limit the energy density of these capacitors to less than 0.5 J/cc. However, advances in pulsed power switches, capacitors and cold cathode anode materials are necessary to develop compact, reliable electric power on directed energy systems as well as advanced air and space platforms. All these areas are within the scope of this topic.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.02.B9076: Advanced Gas Lasers and High Performance Computing Simulation of Multi-Physics

Madden, T.J.

(505) 846-9076

This research is comprised of the physical processes that underlie gas lasers: laser physics, optics, physical chemistry, spectroscopy, and fluid dynamics. Gas lasers use various mechanisms for generating a population inversion within the gas: chemical reactions, electric discharges, rapid gas dynamic expansion, and optically pumping. As a part of the generation of the population inversion, chemical kinetic processes may support or erode the inversion, having a significant impact upon laser performance in conjunction with spontaneous and stimulated emission of photons. Spectroscopy plays an important role here with broadening processes associated with the lineshape of the lasing transmission, measurement of intermediate species populations, determination of gas temperature, and visualization of the flow structure providing critical roles. With a population inversion in place, lasing action occurs with the optical physics interplay with the laser gain generated in the gas media dictating power extraction from the gas. Stable and unstable resonator configurations are used with novel resonator configurations being of interest. As all of these processes occur within a gas, fluid dynamics play a critical role with flow stability, unsteadiness, and transition in subsonic through supersonic flows from very low to high Reynolds numbers being significant. Research opportunities exist related to all of the above areas in both experimental and theoretical capacities. Within the theoretical discipline, modeling of these complex physical processes utilizing high performance computing on very large parallel architectures is a significant activity with research opportunities in the various associated disciplines being available.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.03.B4320: Algorithm Development for Electromagnetic Plasma Simulation

Greenwood, A.D.

(505) 846-6642

Electromagnetic and low density plasma simulations have been dominated by the finite difference time domain technique coupled with a particle-in-cell approach. This dominance has been fueled by the relative ease of implementation combined by the nominal second order accuracy the scheme provides. The robustness of the scheme, combined with highly efficient parallel programming has allowed researchers to solve challenging problems with high confidence. However, due to the increased resolution available through high performance computing, many limitations have been reached with the aforementioned scheme, such as accurate geometric representation, physically realistic representation of particle emission, correct simulation of subgrid forces, and efficient simulation of high density plasmas. Many of these issues are observable in real-world simulations as an increased error, dropping a nominally second order scheme to first order or below. This tendency is often seen in many of problems of interest to the Air Force Research Laboratory's Directed Energy Directorate (AFRL/RDH). For example, it is seen in simulations of high power microwave devices, and it represents a major issue in the design process.

The goal of this research is to advance the state-of-the-art in EM/EM-PIC/EM-Fluid/EM-PIC-Fluid hybrid/parallel computing for improved simulation capabilities of HPM sources. This work spans the realm from basic to applied research and should result in both publications and potential incorporation into our in-house 3D highly parallel EM-PIC code. The candidate will have the unique opportunity to develop algorithms from scratch, incorporate the algorithm in a multiphysics code, and validate against real-world problems currently being studied in the laboratory.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.03.B4500: Analysis of Strong Turbulence Effects on Laser and Speckle Propagation

Gudimetla, V.S.

(808) 875-4500

NOTE: This opportunity will take place at the research facility in Maui.

Although strong atmospheric turbulence is often encountered in many space (low elevation angles) and horizontal paths, no large efforts were made to analyze the problem critically via analytical approaches. Simulations based on phase screen approaches have been done and some mitigation methods have been invented. Some work has been done in characterizing the moderately strong optical turbulence and its effects on the histograms of the intensity. But no efforts were made to arrive at analytical expressions for various optical system parameters in deep turbulence. This field was active in late1970s and early 1980s and since then, no publications have appeared except in the subtopic of the histograms of intensity and some related efforts such as coherence length. Hence, to develop a clear understanding of the problem and to optimize the methods of mitigating the strong turbulence effects in such important applications as space based imaging and the design of adaptive optics systems, a critical examination of various phenomena in strong turbulence in spatial, temporal and related spectral domains is needed. Here, we propose to examine the role of Kolmogorov spectral wave numbers in affecting the various important optical parameters such as Fried coherence length, isoplanatic angle, spectra of figure and tilt and several other optical parameters and use this information to develop analytical expressions. We expect that the resulting expressions to be multi-dimensional integrals and will use USAF super-computing resources available locally to calculate the results and complete the problem by comparing the data with simulations from the phase screen approach and experimental data if needed. This analysis work supports several on-going projects in space imaging, sodium guidestar beacons and related problems and deep turbulence mitigation.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.03.B5386: Quantum Chemistry/Ab Initio Modeling of High Current Cathodes

Shiffler, D.A.

(505) 853-3906

As part of an ongoing research effort, the Air Force Research Laboratory (AFRL) seeks to extend the state-of-the-art in this area for application of these techniques to the high electromagnetic field environments of Directed Energy devices. In this regard, AFRL would like to pursue ab initio modeling of cathodes, electron collectors, and high energy dielectric materials. Ab initio modeling techniques, or quantum chemistry, have shown a great deal of promise for not only reproducing known material behavior, but also for building predictive capabilities for condensed matter physics and surface physics. Work would initially focus on refining the understanding of existing cathodes, but would then extend to the prediction of new material properties based on computer models, with the realization that such new materials should lend themselves to synthesis as well as support the AFRL mission. Particular areas of interest consist of work function and emission threshold dependencies on surface coatings and absorbates. In the course of this work, computational researchers would be required to work closely with scientists working on existing experimental devices and platforms.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.03.B5387: Effects on Radio Frequency (RF) Radiation on Electronics

Clarke, T.J.

(505) 846-9107

Our research focuses on modeling the interaction between continuous wave (CW) and pulsed radio frequency (RF) fields and analog and digital electronics. This includes large scale finite difference time domain (FDTD) modeling of the propagation of RF energy to an electronic device and the internal field structure that is established, as well as modeling the coupling of energy to cables and electronic components and circuit traces. It also includes predicting the effect of this coupled RF energy on the functioning of the electronic circuit. In addition, we are interested in modeling effects on large scale electronic systems comprising very large numbers of such circuits. This research involves performing electromagnetic modeling, as well as building new models describing the interaction with electronics and comparing the results from these models with experimental data to validate and improve the models.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.03.B6642: State-of-the-Art, Massively Parallel Computational Electromagnetics

Greenwood, A.D.

(505) 846-6642

Basic research in computational electromagnetics produces promising new techniques in terms of scaling and problems that can be solved. However, results for these techniques are often shown only for a few small test cases. Before the new methods can make an impact on production level simulations, more work is needed for validation and verification as well as to show that the techniques can be implemented fully in three dimensions and can scale to large numbers of processors on modern parallel architectures. Parallel implementation and scaling becomes an even larger concern with the anticipated move to multicore computer architectures with increasing numbers of cores on a single chip, but not necessarily an increase in bandwidth for transfer to off-chip memory. Areas of interest include, but are not necessarily limited to, fast matrix solution techniques (including robust preconditioners, both dense and sparse matrices as well as sparse-dense matrices from finite element-boundary integral techniques, and matrix compression techniques), finite-element time-domain analysis (including implicit time-domain techniques, efficient solution of mass matrices on massively parallel architectures, local terminating boundary conditions, higher order basis functions, complex material modeling, antenna feed network modeling, and the efficient, accurate addition of charged particles to the method), finite element tearing and interconnect (FETI) techniques (including use of FETI to accelerate interprocessor communication, continuous and non-continuous mesh analysis for multi-scale problems, and use of FETI for modeling finite periodic structures).

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.03.B9101: Simulation of Plasmas and High Power Microwave Devices

Mardahl, P.

(505) 846-8571

The Air Force Research Laboratory is at the forefront of high-performance computing for the Department of Defense. The High Power Microwave Division has a solid record of developing plasma and electromagnetic simulation software. Researchers use these codes to investigate various concepts involving collisional and collisionless plasmas, in collaboration with investigators at other laboratories to help design and diagnose a variety of experiments. The HPM Division has access to some of the most advanced high-performance parallel computing platforms available, including machines with 1000s of CPU. Over the past few years, the division has developed portable, parallel, three-dimensional plasma physics simulation codes for complex geometries, using particle-in-cell (PIC), multi-fluid, and hybrid approaches.

Our principal goal is to improve the state-of-the-art of plasma physics simulations to enable virtual prototyping of high-power microwave devices. As advanced Air Force weapons concepts move from the laboratory to the field, the size of the packages must generally decrease. This effective decrease in the characteristic length scale increases the relative importance of diffusive processes compared to convection. We seek applicants with strong backgrounds in physics and the application of large-scale scientific computation for plasmas and charged-particle beams that interact with complex structures.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.13.B1205: Modeling studies of complex nonlinear systems for defense applications

Bochove, E.

(505) 846-4639

Participants in the program are expected to perform analysis of complex nonlinear systems, the nature of which is subject to his or her choice.

Topics of special interest will be given priority, such as, for example: atmospheric propagation of laser arrays through deep turbulence with application to targeting and destroying enemy missiles; modeling of biological and physiological systems, including sensory and cognitive behaviors of the central neural system; pattern recognition; the spread and control of pandemics; the treatment of disease by medication, radiation or other therapies; ecological and environmental studies, including predictions of climate change and its effects; political, social and economic system modeling, etc.

New mathematical and/or computational methods are sought, e.g. based on neural-net techniques, but the features in the models of nonlinearity, feedback, scaling capacity and complexity, massive interconnectivity, or others relevant to the proposed subject, are desired. Phenomena of interest include bifurcations and instabilities, chaos, and self-organization, but mathematical models should be founded on empirical precedent.

AFRL/RD KIRTLAND AIR FORCE BASE, NEW MEXICO

SF.10.14.B1024: Advanced Estimation Techniques for Satellite Characterization

Luu, K.

(808) 874-1608

NOTE: This opportunity will take place at the research facility in Maui.

We are interested in applying advanced estimation techniques, such as sigma point filters and particle filters, to help us determine state parameters related to satellite properties and operating modes. Input data include, but are not limited to, photometric light curves and poorly-resolved imagery. A physics-based forward model provides the necessary transformation between measurement space and state space. Beginning with an initial guess of the state parameters and a priori covariance, the estimator then systematically adjusts the state parameters in order to match the measurements. The results give us an estimated state with error bounds at each time step. We use Monte Carlo analysis to assess the realism of the error bounds. Current work attempts to incorporate consider parameters, estimate biases, and handle additional data types.

AFIT WRIGHT PATTERSON AFB

SF.50.00.B5157: Chemical, Nuclear, and Biochemical Measurements and Computations Applied to CBRN Objectives

Burggraf, L.W.

(937) 255-3636

Experimental and theoretical methods of chemical physics are applied to CBRN proliferation problems. Three projects illustrate the wide range of research interests: (1) characterization and inactivation of Ba and Bt bacterial spores, (2) surface chemistry of uranium oxides and contaminant metals (3) gamma imaging using Compton backscatter radiation, annihilation radiation and gamma absorption.

We have demonstrated that topological and phase images measured using atomic force microscopy (AFM) can distinguish spores of bacillus anthacis from closely related bacterial spores based on differences in surface properties. Recently, we have applied nano-mechanical measurements of polymer surfaces using atomic force microscopy (AFM) to characterize and distinguish bacillus spores. We are developing dynamic models of these nano-mechanical AFM measurements. We are beginning to apply these AFM techniques to compare differences in properties of viable and thermally inactivated bacillus spores. These AFM methods are companioned with novel spore isolation methods to rapidly measure germination times and outgrowth rates of variously treated spores using microscopic measurements. We intend to extend these measurement techniques to characterize bacillus spore inactivation by a variety of nano-particles. We have developed a laser heating method to expose spores to a high-temperature inactivating thermal of short time duration. We are extending this method to not only simulate the temperature-time profiles of conventional and nuclear explosions, but we are developing a method to also simulate their spectral distributions.

Uranium dioxide from nuclear fuel processes or depleted uranium munitions may be dispersed into environments. Particles of uranium dioxide react further in the atmosphere by oxidation and formation of complexes (hydrates, hydroxides, and carbonates), increasing the mobility and bioavailability of uranium, contaminant metals and fission isotopes. Spectroscopy and kinetics surface species on UO2 are measured, using spectroscopy tools including: photoluminescence (LIBS), Raman spectroscopy, Fourier transform infrared (FTIR), secondary ion mass spectrometry (SIMS), x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD). Spectroscopy signatures of various oxidation states and crystalline forms of uranium oxides, hydroxides, and carbonates are measured over time, controlling gas dosing and temperature, using these spectroscopy tools. Quantum methods are being developed to model spectroscopy of point defects in solid state systems.

We are developing methods to employ planar high-purity germanium (HPGe) strip detectors to imaging applications including positron annihilation measurements and Compton/absorption gamma imaging. Previously we demonstrated two-dimensional nondestructive tomography of hidden structures by measuring Compton backscattered gamma rays, which permits imaging when access is available to only one side of an object. We are constructing a gamma spectrometer to simultaneously measure DBAR (Doppler broadened annihilation radiation) and ACAR (angular correlation annihilation radiation) spectra. These approaches are being evaluated for nuclear weapons inspection and field-detection of special nuclear materials using portable HPGe detectors.

AFIT WRIGHT PATTERSON AFB

SF.50.00.B5160: Characterization of Mid-Infrared Quantum Well Optoelectronic Devices

Hengehold, R.L.

(937) 255-3636

Research focuses on the optical characterization of mid-infrared (MIR) semiconductor lasers and detectors. In the proposed research, the performance of MIR semiconductor lasers and detectors will be optimized by determining the designs and fabrication processes that enhance the performance of these devices. This requires accurate knowledge of the quantum well dispersion relations for these structures. Such knowledge can be obtained through a closely coupled theoretical and experimental effort. Our research will close the loop between theory and experiment for the first time. The resultant data is essential to maximize the performance of both MIR laser and detector devices.

For the theory, we will use an existing software package, developed at AFIT. This package will help us determine the relationship between the growth parameters used during the fabrication of the devices and the resulting quantum well properties to be optimized. In particular, quantum well dispersion relations will be computed and compared with experimental hot electron luminescence and time-resolved spectroscopy measurements as both a guide to experiment and a verification of the theory.

The experimental aspect of this proposal is twofold. The first involves the verification of the calculated dispersion relations through experimental measurements of photoluminescence and hot electron spectroscopic measurements. The hot electron measurements will be extended for the first time into the MIR. Narrow band-gap semiconductors (e.g., ternary antimony [Sb] compositions used in MIR lasers) are especially susceptible to temperature-dependent, nonradiative processes such as Auger recombination (thus, the need for band-gap engineering). The second involves time-resolved spectroscopy using PL-upconversion to resolve carrier recombination on a sub-picosecond time scale, and differentiate between the radiative and nonradiative (Auger, Shockley-Read-Hall) recombination processes in these supper-lattice structures. This will allow accurate fine-tuning of the underlying computational model of Sb-based QW lasers for the first time. The results of this project are directly applicable to AFRL's MIR laser development program.

AFIT WRIGHT PATTERSON AFB

SF.50.00.B5163: Coatings for the Mitigation of Material Damage that are due to High Energy Impact

Palazotto, A.N.

(937) 255-3636

In the investigation of high-energy impact bought about at velocities exceeding the speed of sound, temperature distribution may exceed ranges that change the material phases. To overcome certain wear characteristics, it is important to formulate a thermal distribution through the structure in the immediate vicinity of the impact. In order to mitigate the effects observed at the point of impact, we have found that the application of coatings is influential. Research focuses on evaluating the effects of temperature distribution on the success of coating application considering friction, aerodynamic heating, and heat transfer. The impact velocity will be evaluated over ranges less than and greater than the speed of sound.

AFIT WRIGHT PATTERSON AFB

SF.50.00.B5164: Chemical Lasers and Laser Spectroscopy

Perram, G.P.

(937) 255-3636

Experimental research in laser physics, spectroscopy, chemical kinetics, nonlinear optics, and photochemistry form the basis for advanced laser demonstrations and development. Several technologies supported by the AFIT laser weapons research group include:

(1) Airborne Laser. The megawatt class Chemical Oxygen-Iodine Laser (COIL) is the weapon system aboard the Airborne Laser, designed to destroy theater missiles during the boost phase. AFIT has a more than 20-year history support the Air Force's high-energy laser program. Recent AFIT research in support of COIL devices include analyzing gas phase reaction rates, studying the effects of nozzle material on energy losses, and developing optical diagnostics to measure the supersonic gas temperature.

(2) Infrared Countermeasures. New, moderate power laser sources are required for electro-optic countermeasure missions such as blinding heat-seeking missiles. We are investigating photolytic gas phase laser systems and nonlinear optical techniques to develop new lasers operating in the near infrared at 3-5 microns.

(3) Remote Sensing. Space surveillance systems depend on the detection of electromagnetic radiation to interrogate the battlefield environment. Recent research activities include collecting spectral signatures from bomb detonations, examining spectral lineshapes necessary for probing meteorological conditions, and developing lasers for remote-sensing and counter proliferation applications.

(4) Optical Diagnostics. New optical methods for detecting and monitoring chemical processes are in high demand. Several examples of AFIT's activities in developing optical diagnostics include (1) assessing desorption of soil contaminants from aircraft degreasing operations, (2) studying thin-film processing from laser ablation and plasma processing, and (3) characterizing combustion chemistry. Emphasis is placed on the fundamental plume dynamics and spectroscopy in pulsed laser deposition of high-temperature superconductors to enable the manufacture of superconducting wires for aircraft power generation.

(5) Space Operations. The fundamentals of atomic, molecular, and optical physics also find application in space systems. Recent AFIT research activities include studying the photochemistry of stratospheric ozone depletion from space launch activities, examining the collisional dynamics in atomic clocks for Global Positioning System applications, and elucidating ionization mechanisms in the thermosphere for satellite survivability. Solar pumped lasers may find application for space-based missions involving long duty cycles such as de-orbiting space debris and power beaming.

AFIT WRIGHT PATTERSON AFB

SF.50.00.B5167: Molecular Reaction Dynamics

Weeks, D.E.

(937) 255-3636

The detailed analysis of a wide variety of chemical reactions plays a central role in a number of Air Force and DOD applications ranging from the chemical oxygen iodine laser, to upper atmospheric chemistry, to the development of new high energy density materials. To support these efforts, we are developing new computational methods to characterize chemical reactions. Our approach employs time dependent wave package dynamics to calculate scattering matrix elements and associated reaction rates and cross sections. Initial efforts have focused on developing this new time dependent technique through the analysis of inelastic collinear reactions of type A + BC -> C, incorporating the translational and vibrational degrees of freedom. More recent efforts have successfully incorporated the rotational degree of freedom and we are currently focusing on the non-adiabatic reaction B + H2. For these calculations, we are including the rotational and vibrational degrees of freedom of the hydrogen molecule together with the electronic degrees of freedom of the Boron atom. Future efforts include the extension of the technique to four atom reactions, and the continued refinement of time dependent techniques for computing scattering matrix elements. Researchers with experience in computational physics, molecular dynamics, wave packet propagation, or related areas are encouraged to apply.

AFIT WRIGHT PATTERSON AFB

SF.50.00.B5168: Electrical, Optical, and Magnetic Studies of Various Narrow to Wide Bandgap Semiconductors

Yeo, Y.K.

(937) 255-3636 x4532

Research will focus on the electrical, optical, and magnetic characterization studies of various semiconductors including group IV-IV semiconductors such as GeSn and SiGeSn, group-III nitrides such as GaN and AlGaN, II-VI semiconductors such as ZnO, and mid to narrow bandgap semiconductors such as InGaAs and InAsP for the development of infrared to blue and ultraviolet wavelength range of optoelectronic devices, high-power, high-temperature, and high-frequency electronic devices. The characterization methods include temperature dependent Hall-effect/sheet resistivity, temperature dependent current-voltage, capacitance-voltage, deep level transient spectroscopy, transmission line, photoluminescence, electroluminescence, cathodoluminescence, absorption (transmission), superconducting quantum interference device (SQUID) measurement techniques. A background in various semiconductors and their electrical, optical, and magnetic characterization techniques and in simple optoelectronic device processing techniques is desirable. This research program will contribute to an existing Air Force effort characterizing various bandgap semiconductor materials and devices.

Keywords: Wide bandgap semiconductors, Narrow to Mid bandgap semiconductors, Hall-effect measurements, Photoluminescence, Cathodoluminescence, Deep level transient spectroscopy, Superconducting quantum interference devices, Gallium nitride, Zinc oxides, Germanium tin

AFIT WRIGHT PATTERSON AFB

SF.50.00.B5169: Organophosphate Compound Detection

Goltz, M.N.

(937) 255-3636

Organophosphate (OP) compounds are among the most toxic substances known. They are used not only as chemical warfare agents, but also as pesticides and insecticides. Equipment is available to detect OPs in order to protect our troops and DOD workers, but the detection methods leave a lot to be desired. What is needed is a fast, accurate, and affordable detector with a low detection limit that can be easily carried by front-line troops in combat and our industrial workers who deal with OP compounds. In this study, we investigate the potential of using enzyme-based biosensors to rapidly and accurately detect OP compounds in the liquid and gas phase.

AFIT WRIGHT PATTERSON AFB

SF.50.00.B5176: Physical Design Optimization for VLSI Silicon Technologies

Lanzerotti, M.Y.

(937) 255-3636 x4442

In the current standard VLSI chip design practice, one physical design for a specified logic design is generated for manufacturing in a state-of-the-art silicon technology, although multiple physical designs can exist that satisfy project requirements. With the increasing importance of VLSI silicon technologies, methods are needed to produce optimize physical designs that minimize undesirable properties such as power consumption while increasing desirable properties such as performance, yield, and robustness (thereby decreasing risk of chip failure). To address these needs, interdisciplinary research to develop computer-aided design algorithms and tools that incorporate additional functionality is focused in three areas:

1. First, it is desirable to incorporate electrical parameters such as capacitance, resistance, wire delay, and signal transition rates, as well as mechanical parameters and fabrication constraints that describe wire and via structures into the computer-aided design tools;

2. Second, guidelines and statistical frameworks for methods to wire an ‘unwirable’ chip are also desired; ‘unwirable’ chips include those chips that require custom design, or manual intervention due to inadequacies of an automated routing algorithm that is assigned to complete a complex chip design task;

3. Third, it is desirable to develop efficiency metrics that will enable the comparison of various physical designs on the same chip depending on the most important optimization parameters in VLSI silicon technologies.

AFIT WRIGHT PATTERSON AFB

SF.50.00B0814: Applied Harmonic Analysis and Mathematical Signal Processing

Fickus, M.

(937) 255-3636 x4513

Recent mathematical advances in the fields of frame theory and compressed sensing are revolutionizing the ways in which we measure, process and represent signals. Frame theory is the study of redundant linear decompositions, that is, how to represent a given signal in terms of an overcomplete spanning set. Frames are particularly useful in applications where traditional orthonormal-basis type decompositions are insufficient. Compressed sensing is a related field that focuses on decomposing signals which are a sparse linear combination of a large overcomplete set. It provides a mathematical formalism for justifying the intuition that low-complexity signals can be sensed with a correspondingly small number of measurements.

We are investigating several of the most challenging open problems of frame theory and compressed sensing: (1) Deterministic construction of Restricted Isometry Property (RIP) matrices and Numerically Erasure-Robust Frames (NERFs); (2) Phaseless reconstruction, that is, the design of frames that permit the reconstruction of any signal from the absolute values of its inner products with the frame vectors; (3) New constructions of Equiangular Tight Frames (ETFs) and other low-coherence dictionaries; (4) the Paulsen problem, and more generally, a better understanding of the manifold of all unit norm tight frames.

These problems have applications to remote sensing, communications, tomography, quantum information theory, and digital fingerprinting. The research itself draws inspiration from a wide variety of mathematical fields. Specializations in one or more of the following areas are particularly useful: frame theory, compressed sensing, matrix analysis, sphere packing and covering, Fourier transforms, wavelets and filter banks, algebraic geometry, algebraic coding theory and combinatorial block design.

AFIT WRIGHT PATTERSON AFB

SF.50.01.B4576: Analytical Modeling of Half-Life Learning Curves in the Defense Acquisition Lifecycle

Badiru, A.

(937) 255-3636 x4799

Learning curves have been used for decades to assess improvement achieved over time due to the positive impact of learning. Early analytical modeling of learning curves focused on reduction in cumulative average cost per unit as production level doubles. Several alternate models of learning curves have been presented in the literature over the decades. The classical models have been successfully applied to a variety of problems. In recent years, the deleterious effects of forgetting have also been recognized. It has been shown that workers experience forgetting or decline in performance even while they are making progress along a learning curve. Consequently, contemporary learning curves have attempted to incorporate forgetting components into learning curves. It is of interest to study how fast and how far the forgetting impact can influence overall performance. This research introduces the concept of half-life analysis of learning curves using the concept of growth and decay, with particular emphasis on applications in defense acquisition process. Half-life is the amount of time it takes for a quantity to diminish to half of its original size through natural processes. Although the common application of half-life is in natural sciences, the computational analysis lends itself to application to learning curves, particularly for designing training programs and assessing worker performance. This is useful and desired in the Human Performance research within DOD. It is a natural process for people to learn, unlearn, and relearn. Capturing this process in a quantitative framework is essential for making effective decisions in any operation, particularly in the defense acquisition environment, where human-machine interfaces are common. Because the degradation of learning does not follow a linear path, it is essential to monitor the various stages of the learning, unlearning, and relearning processes. This research involves analytical modeling of the stage when a learning profile has degraded to half of its initial value. This is useful for predicting the magnitude and behavior of learning over time. The half-life point can be used for acquisition training and retraining purposes. With the techniques in this research, a breakeven analysis of learning can be computed because the upswing of learning and the downswing of learning conceptually intercept at some point. It is of interest to know whether that interception point occurs before or after the half-life point. For the purpose of training in acquisition operations, we can use the half-life computational technique to estimate what fraction of training retention remains after some point in time and what level of retraining might be needed during the acquisition life cycle.

Keywords: Learning curve, half-life, learn-forget models, performance, training, DOD acquisition

AFIT WRIGHT PATTERSON AFB

SF.50.01.B5171: Mission Assurance: Impact Assessment and Situational Awareness

Grimaila, M.R.

(937) 255-3636 x4800

Virtually all modern organizations have embedded information systems and networking technologies into their core processes as a means to increase operational efficiency, improve decision making quality, reduce delays, and/or maximize profit. Unfortunately, this dependence can place the organization's mission at risk when an information incident (e.g., the loss or degradation of the confidentiality, integrity, availability, non-repudiation, or authenticity of a critical information resource or flow) occurs. This research focuses on developing solutions to provide decision makers with timely notification and relevant impact assessment, in terms of mission objectives, following an information incident.

AFIT WRIGHT PATTERSON AFB

SF.50.01.B6134: Combustion Dynamics for Novel Combustor Systems

Polanka, M.

(937) 255-3636 x4714

As future requirements lead toward compact, efficient engine designs, conventional gas turbine component design methodology will become more integrated to provide higher performance systems. Several concepts are being explored to obtain lighter weight, more efficient, lower fuel consumption combustors. One example of this integration of components is the Ultra Compact Combustor (UCC). In this configuration, fuel is deliberately added circumferentially above the vane geometry to accomplish combustion simultaneously while the flow is turned by the vane. Research areas have focused on the combustion mechanisms at high g-loading and radial migration of the hot combustion gases into the integrated vane along with investigations into Rayleigh losses associated with higher Mach number combustion. With optical diagnostics such as PIV, PLIF, TDLAS, and CARS in place in the laboratory, the capability to completely understand these complex burning configurations exist. Future efforts will continue to understand the integration issues with the compressor and turbine. New efforts specifically geared at understanding how to cool the turbine appropriately in this high equivalence ratio environment will also be developed.

Another research area focused on the combustion process in small engines used in Remotely Piloted Aircraft. These investigations have focused on attempting to understand the impact of the inlet flow conditions, namely the altitude effects, that can impede the performance of these small IC engines. An altitude chamber has been built that enables control of the pressure and temperature within and around the engine. Investigations into fuel injection, timing, and heavy fuels are possible to understand the performance and the specific fuel consumption of the engine.

Keywords: Combustion, Diagnostics, Novel Combustors, RPAs, Internal Combustion Engines

AFIT WRIGHT PATTERSON AFB

SF.50.01.B7843: Radio Tomographic Imaging

Martin, R.

(937) 255-3636 x4625

Device free localization is the process of tracking users who are not emitting a radio signal. An emerging method of doing this is radio tomographic imaging (RTI). RTI involves setting up a dense network of radio sensors. When a user physically enters the network, it will obstruct a subset of the network links. By measuring the change in signal strength on all network links, it is possible to compute a 3D image indicating which voxels are obstructed. This can in turn be used for target tracking and identification. Of particular military interest is the fact that RTI can be used for imaging through walls and foliage; for example, work at AFIT has demonstrated imaging capabilities through foot-thick concrete walls.

Current RTI research at AFIT includes (i) improving the physical model relating the presence of a user to the change in radio signal strength, while accounting for multipath, (ii) improving the performance of the imaging algorithm, (iii) improving the system implementation by reducing computations or designing an application-specific communication protocol for the sensors, and (iv) developing target tracking and identification tools.

AFIT WRIGHT PATTERSON AFB

SF.50.02.B7123: Fracture and Fatigue of Advanced Materials/MEMS

Mall, S.

(937) 255-3636 x4587

Active research is in progress to characterize the deformation mechanisms, fracture and fatigue behavior for structural materials including conventional polymeric composites, high temperature composites, nanocomposites. Also, contact mechanics issues in MEMS are being investigated. We are interested in the experimental as well as modeling efforts of mechanical response of and damage mechanisms in materials under myriad of loading conditions, such as high cycle fatigue, low-cycle fatigue, fretting foreign object damage, creep, fretting, thermo-mechanical fatigue, etc. Unique experimental facilities for testing are available. Research focuses on developing the scientific base and fundamental understanding.

AFIT WRIGHT PATTERSON AFB

SF.50.11.B1128: Fate of Chemical Warfare Agents in Engineered and Natural Systems

Racz, L.

(937) 255-3636 x4711

Highly toxic organophosophates (OPs) have been widely used as Chemical Warfare Agents (CWAs) as well as pesticides since World War II and still remain a threat to national security. In the event of a chemical incident, standard operating procedures dictate that contaminated personnel be decontaminated. Often times, decontamination is accomplished with water. Many communities plan for this decontamination water to be sent to the local municipal wastewater treatment plant. However, the fate of these compounds in a municipal wastewater treatment plant is largely unknown. If the compounds cannot be degraded, they will enter surface water bodies with plant effluent or waste sludge.

This research effort will use CWAs and their simulants in bench-scale activated sludge bioreactors to determine the biotic and abiotic mechanisms that affect the fate of these compounds. Bioreactor conditions will also be varied to study the effect of operational parameters on these compounds. In addition, advanced molecular techniques may be used to study which enzymes in the activated sludge bacteria can be attributed to OP biodegradation. This work will help to understand the risks of CWA reentering the environment from a wastewater treatment plant following a CWA incident.

AFIT WRIGHT PATTERSON AFB

SF.50.13.B0821: Precision Navigation

Raquet, J.

(937) 255-3636 x4580

The Advanced Navigation Technology (ANT) Center is focused on developing robust position, navigation, and timing (PNT) solutions that enable highly accurate and very precise navigation capabilities in Global Positioning System (GPS)-denied or contested environments. To this end, the research and development (R&D) efforts of the ANT program concentrate on the following research thrusts:

• Autonomous and Cooperative Systems: Increasing autonomy and cooperation between remotely controlled vehicles to perform tasks (such and targets, mapping, etc.) more efficiently and/or more precisely

• Non-GPS Precision Navigation: Development of non-GPS technologies and integration schemes for GPS-level or better navigation and time accuracy to support precision combat in all environments. Current research efforts include using signals of opportunity such as cellular networks and wi-fi, vision and optical flow, gravimetric measurements, LiDAR, magnetic field variations.

• Robust GPS Navigation/Navigation Warfare (NAVWAR): Expansion of the GPS “operating envelope” in terms of jamming, high dynamics, and precision differential GPS, so United States military forces maintain the performance advantage of GPS over all potential adversary systems. This includes consideration to foreign global navigation satellite systems (GNSS).

AFIT WRIGHT PATTERSON AFB

SF.50.14.B0835: Network Management, Cyber-Security, Visualization and Data Mining

Hopkinson, K.

(937) 255-3636 x4579

The Cyber-Advanced Networks in Mobile Applications Laboratory (Cyber-ANiMAL Lab) is focused on developing innovative methods for managing and securing networks as well as data mining and visualization. Current research efforts include the following

• Using Cognitive Radio Networks for Spectrum Sharing: This effort involves creating networks of cognitive radios with the goal of mapping spectrum and then making using of bandwidth underutilized by primary users.

• Security in Embedded Environments: This area of research looks at low-overhead methods for security and privacy preservation in embedded environments such as those present in SCADA systems, the power grid, and space environments.

• Automated Enterprise Network Defense: This effort attempts to create intelligent automated systems to augment and enhance system administrator abilities when managing enterprise networks subject to viruses, intrusions, and other forms of attack.

• Data Mining and Visualization: A diverse and persistent array of sensor information is available in a wide range of application domains in modern environments. This area looks at how to apply data fusion and data mining techniques to automatically zero in on points of interest. Innovative visualization tools are explored for us to illustrate the results in an informative and intuitive manner.

• Security and Task Management in Cloud Systems: This research concentration looks at cloud computing from two perspectives. The first looks at methods for better managing dynamic service loads in the control plane in cloud systems. The second concentration area looks at ways to manage encrypted data and meta-data in cloud environments.

AFIT WRIGHT PATTERSON AFB

SF.50.14.B0836: Activity Based Intelligence – Determination of Human Activity Using Unresolved Optical Data

Borel-Donohue, C.

(937) 255-3636 x4957

Much of the current work on human behavior and activity recognition using electro-optical sensors focuses on near-range sensors producing relatively high resolution (1-5 cm) images. In contrast, currently fielded full motion video (FMV) and wide area motion imagery (WAMI) sensors can just barely spatially resolve a person (10 to 100 cm GSD). Determination of suspicious individuals or groups of people from low resolution optical data collected by remotely positioned sensors enables identification of suspicious behaviors through persistent stand-off surveillance. This study will address these limitations by investigating one of the following areas: Extension of current computer-vision based behavior analysis methods to WAMI and FMV data; Assessment of the minimum required spatial/temporal resolution to determine activity recognition at an individual and/or crowd level; Use of other information from multiple sensor modalities and geospatial information to augment low-resolution WAMI and FMV.

AFIT WRIGHT PATTERSON AFB

SF.50.14.B1105: Small Satellite Research and Development

Swenson, E.

(937) 255-3636 ext 7479

AFIT designs, builds, and tests satellites and space experiments as part of their education and research mission. As part of their STEM efforts, AFIT students and researchers designed and developed a standard 3U CubeSat that is currently awaiting launch. AFIT students and researchers are currently in the process of developing a larger and more capable 6U CubeSat. The 6U can carry larger and more capable payloads and AFIT researchers are focused on incorporating payloads that are of direct interest of the DOD. A summer fellow, with expertise in the area of satellite design and test, will not only enrich DOD officer’s and civilian’s satellite educational and development experience but also numerous local interns who will also work at AFIT over the summer. It is expected that a summer fellow would also participate in AFIT’s planning and development processes all while contributing to the various phases of construction, assembly, and testing all of which will be performed in-house. These efforts will be ultimately focused on research, design, and education with regards to DOD space payloads and satellites. The primary benefits will likely occur from the summer fellow directly interacting with AFIT students and interns throughout the entire design and build process. Additionally the summer fellow will perform research in the fields of small satellite bus and payload technology development, including, but not limited to, imaging and signals collection payloads, and power and attitude control subsystems.

AFIT WRIGHT PATTERSON AFB

SF.50.14.B1125: Biological Process Research for Environmental Applications

Harper, W.

(937) 255-3636 ext 4528

My research explores biological processes that are important in a range of environmental applications, with a primary focus on water quality. Currently-sponsored projects are focused on the removal of organic chemicals, biosensing, and resource recovery. Research activity combines traditional research approaches, such as mathematical modeling and laboratory-scale experimentation, with the modern tools from chemistry and microbiology, and research based on this combination uncovers knowledge and provides exciting opportunities for interdisciplinary collaboration. Although individual projects might emphasize experimentation, modeling, or microbiological aspects, all research involves quantification, the key to making the research results relevant to engineers.

The objectives of our ongoing projects are: 1) to understand and predict the fate of chemical warfare agents and industrial chemicals in engineered water treatment systems, 2) investigate novel biosensors and hyperspectral imaging technology to detect hazardous substances, and 3) evaluate resource recovery paradigms using systems thinking.

AFRL/RH 711TH HPW FORT SAM HOUSTON, TX

SF.15.09.B1144: Theoretical and Empirical Investigation of Nanosecond Electric Pulse-induced Bioeffects

Ibey, B.

(210) 539-7910

Selected projects will assist in the development of theoretical models and empirical techniques to investigate the propagation and related bioeffects of nanosecond electric pulses (nsEP) in isolated cells, tissues, and whole organisms. Current laboratory efforts have focused gathering empirical data on the cellular impact of nsEP using confocal microscopy and electrophysiology. Current modeling techniques used within the laboratory have been limited to finite different time domain (FDTD) methods restricting the model size/resolution available for whole cell simulations. Improvement upon FDTD methods or alternatives to such methods (e.g. FEM) for measuring deposition of electric fields in biological tissue/cells/organelles is of great interest. Development of advanced techniques for measurement of cellular response to nsEP is also of great interest with focus on utilization of atomic force microscopy/scanning ion conductance. Areas of work include (1) advanced numerical techniques for quantification of electromagnetic pulse propagation in cells/tissue, (2) molecular dynamic simulation of plasma membrane breakdown during electrical pulse exposure, (3) use of atomic force microscope/ion conductance microscopy for measuring cellular response to ultrashort electrical pulses, (4) high resolution imaging for analysis of plasma membrane disruption during electrical pulse exposure, (5) any empirical techniques capable of measuring plasma/organelle membrane breakdown or subtle changes in cellular function. Candidates with demonstrated experience in the fields described or possessing applicable related methods are desired. Selected applicants should expect to work with USAF staff, collaborating university faculty, and summer students at the graduate and undergraduate level.

AFRL/RH 711TH HPW FORT SAM HOUSTON, TX

SF.15.10.B3740: Laser-Tissue Interaction

Oliver, J.

(210) 539-8145

The goal of this research is to determine the effect of laser exposure on human tissues and to study the resulting mission impact. The analysis includes quantification of tissue parameters, response of tissues to optical irradiation, and modeling of the interaction. We study photoacoustic, photothermal, cellular insult, photochemical, and photomechanical processes and their effect on tissues. Understanding laser tissue interaction is the first step toward optimizing military application of laser radiation. Our work emphasizes the occupational and environmental health aspects of laser tissue interaction, with experiments coupled with modeling efforts, which result in suggestions to the laser safety community where safety standards either do not exist, or where deficiencies in biological data has made the criteria for setting standards ambiguous. In addition, we seek to understand and monitor changes in tissue optical properties and function as a result of laser exposure. The laboratory offers extensive laser facilities and support equipment (including retinal and skin imaging) to investigate effects across the pulse-duration and wavelength spectrum.

AFRL/RH 711TH HPW FORT SAM HOUSTON, TX

SF.15.10.B3743: High-Power Microwave Bioeffects Research

Jauchem, J.

(210) 536-3572

Recent developments in electromagnetic technology have resulted in exposure sources capable of generating high-power microwave (HPM) pulses with relatively short pulse widths. As a result of the short pulse width and low pulse frequency (relative to more conventional emitters), the average power density during any period of exposure (and the resultant absorbed energy) is very low. Energy absorption in humans exposed to these systems would be considerably lower than levels suggested as safety guidelines. However, current safety standards for microwave exposure do not address the possibility of effects other than those related to total energy absorbed. Because of the anticipated increase in the use of HPM sources by the Air Force, we must obtain more knowledge about the biological effects of these systems. Our goal is to provide data relevant to health and safety standards related to a wide variety of biological systems. Current research covers a broad range of areas including cardiovascular and respiratory physiology, teratology, behavior science, developmental biology, and cancer biology. We are also interested in developing new techniques for dosimetry of electromagnetic pulses.

AFRL/RH 711TH HPW FORT SAM HOUSTON, TX

SF.15.10.B6039: Visual Effects from Bright Laser Light Exposure; Vision Science, Psychophysics, Behavior/Performance

McLin, L.

(210) 539-8202

This is a multifaceted program integrating vision science, experimental psychophysics, vision modeling, behavior/performance and human factors. A topic of particular interest is conducting experiments to develop and validate the effect of laser glare (dazzle) to establish an international safety standard for laser eye dazzle. The effects of wavelength, atmosphere, and ambient lighting or time of day are variables that should be included in this standard. Another topic of interest is the effect of laser or broadband glare sources on performance dynamic visual tasks with motion. Laboratory psychophysical experiments are conducted to develop and validate vision models for vision over a range of ambient luminance levels from low mesopic to very high photopic. Other related areas of research include spatial vision, intraocular scatter, disability glare, discomfort glare, flashblindness, photostress recovery, macular pigment, color constancy, vision at mesopic levels, color zones and color naming, attention, and eye movements. Candidates with demonstrated laboratory experience in vision science are desired. Selected applicants should expect to work with USAF staff, collaborating university faculty, and contract support staff to develop models and conduct experiments to validate models.

AFRL/RH 711TH HPW FORT SAM HOUSTON, TX

SF.15.10.B6041: Modeling Behavioral Responses to Non-Lethal Weapons

Ashworth, A.

(210) 536-1963

Assist in the development of models to describe the relationship between the physical effect of non-lethal weapons and the behavioral response. Modeling efforts range from process models describing qualitative relations between factors, to computational models for generating quantitative predictions based upon real time data collection. To be considered are: 1) individual psychological factors such as motivation, experience with and knowledge of the weapon, tolerance for pain and discomfort, observation of weapon use on a third party, gender, and age; 2) social factors such as cultural background, religion, group size, conformity, impressions of authority; 3) environmental factors such as ambient levels of temperature, light, and sound; and 4) type of non-lethal weapon such as blunt impact, riot control agents, malodorants, directed energy, flashbang, blast overpressure, and electromuscular stimulation. Candidates with demonstrated experience in the field or applicable associated research are desired. Selected applicants should expect to work with USAF staff, collaborating university faculty, and contract support staff to develop models and draft guidance to inform policy decisions and security classification guides.

AFRL/RH 711TH HPW FORT SAM HOUSTON, TX

SF.15.12.B0906: Laser Eye Protection (LEP), Eyewear Design, and Ocular Vulnerability Modeling and Psychophysical Assessment of the Effects of LEP Devices on Visual Function

Kumru, S.

(210) 539-8244

The end-to-end laser eye protection (LEP) design capability can be accomplished by merging a frame and format design capability with a visual performance metrics and modeling capability to create a single, integrated package allowing complete human systems integration of LEP. Using 3-D mechanical design tools, it can provide for the rapid design and fabrication of prototype frames needed for proper form, fit and function, including integration with head-mounted systems. Using 3-D optical modeling tools, it can quantify and visually render the effects of LEP filters on human vision. The principal challenge to successfully completing this work is software development. Existing software will have to be improved to and integrate existing packages into both the frame/format design and optical modeling packages in hand.

To provide adequate eye protection, the prototype LEP devices (LEPD) specifically block designated wavelengths of laser light using absorptive dyes. If, by filtering out the laser light, the amount of visible wavelengths passing through the LEPD is reduced, visual function may be degraded because of shifts in the appearance of colored stimuli, reduction of contrast, and reduction of the total amount of light available for visual function. Evaluations are needed to determine how and to what extent the prototype LEPDs alter the user’s vision; specifically, their spatial acuity and contrast sensitivity with and without the presence of glare and color vision.

AFRL/RH 711TH HPW FORT SAM HOUSTON, TX

SF.15.12.B0907: Mechanisms of Low Level Light Exposure Bioeffects In Vitro

Wigle, J.

(210) 539-8075

Photobiomodulation (PBM) is the term now used in place of (initially) low level laser therapy (LLLT) and (later) low level light therapy in reference to a general invigoration of cells following exposure to low doses of red or near infrared (NIR) electromagnetic radiation (“light”). Because the first observation was therapy-like, the vast majority of research on PBM has been therapy oriented. However, photobiomodulation has also been shown to protect mouse retina cells in vivo from methanol toxicity and from injurious levels of white light. We have shown that photobiomodulation (2.88 J/cm2) protects human retinal pigmented epithelium (RPE) cells growing in vitro against the lethal effects of a pulse of 2 µm laser radiation. The increased resistance in RPE cells correlates with changes in the expression of genes that control apoptosis, (Bax, Bcl-2, Bcl-xL, Hsp 70, caspase 8, caspase 9, FasL andp53), growth factors ( NF-κB, cyclin D and VEGF-C) and increased ATP levels. We have also found that these changes are largely absent in a VEGF-C knockdown strain of the human RPE cells. More recently, we found that exposure to 637 nm light increases the intracellular levels of nitric oxide (NO), a potent chemical messenger that stimulates soluble guanyl cyclase (sGC) to synthesize cGMP, a potent second messenger molecule, from GTP. Very recently we also found that the source of the NO is one or more of the nitric oxide synthase molecules (iNOS, eNOS or nNOS) in addition to the long-postulated cytochrome c oxidase, Complex IV in the electron transport chain of oxidative phosphorylation. This is the first demonstration of red light stimulating a NOS enzyme. While many physiological changes have been catalogued, the actual biochemical mechanism of these effects remains elusive. In order to exploit PBM to benefit performance and/or protection of the warfighter, and be sure there are no acute or chronic ill effects of manipulating PBM, the biochemical mechanism of the physiological effects must be known. Therefore, the goal of this research is to reveal physical, chemical, molecular, biological, and cellular mechanisms of cell stimulation and viability protection by low level light exposures. The RPE in vitro experimental system is of particular interest, but other ideas/approaches will be considered within our existing capability to provide laboratory support. The influence of light exposures on reduction/oxidation potentials in cells, gene expression (DNA methylation, DNA transcription, and or RNA translation), protein phosphorylation, cell cycle and growth perturbations, cell membrane effects, free-radical production, necrosis and the competing roles of cytochrome c-linked apoptosis and the protective effect of cytochrome c oxidase-linked biostimulation are all of interest.

AFRL/RH 711TH HPW FORT SAM HOUSTON, TX

SF.15.13.B0911: Optical Investigation of Biological Response to Electromagnetic Exposure

Beier, H.

(210) 539-8199

Selected projects will assist in the development or application of advanced optical approaches for investigation of biological response to electromagnetic exposure. Current laboratory efforts are focused on using techniques such as spontaneous and coherent Raman scattering, high-speed imaging, and confocal and multi-photon microscopy, to elucidate effects observed after directed energy exposure. Of particular interest is exploration of effects or specific information that can be gained from low-frequency Raman techniques. Candidates with biological or biochemical expertise seeking to use optical approaches for investigation of their observed phenomenon, as well as those with demonstrated experience in novel optical sensing and imaging approaches, are desired. Selected applicants should expect to work with USAF staff, collaborating university faculty, and summer students at the graduate and undergraduate level. The laboratory offers extensive laser facilities across the pulse-duration and wavelength spectrum with support optical and microscopy equipment.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B0123: Mathematical Optimization in Multidisciplinary Design

Kolonay, R.

(937) 713-7126

The basic objective of multidisciplinary design is to integrate the various disciplines that constitute the environment of an aerospace vehicle. The goal of modern design is to optimize the total system rather than the individual components, permitting the conflicting requirements of the subsystems to be handled much more effectively in getting optimal solutions. Aerospace Vehicle design is a large optimization problem consisting of libraries of variables, constraints, and performance functions. By expanding and contracting these libraries, we can explore the inherent coupling between subsystems and the disciplines and their impact on system level performance. Topics of interest include (1) simultaneous design with multiple constraints; (2) structural requirements derived from strength, stiffness, and frequency considerations; (3) static and dynamic aeroelastic requirements; (4) requirements from acoustic and thermal environments; (5) linear and nonlinear aerodynamic interactions with the structure and control system; (6) tailoring of composites and other new materials; (7) shape and topology optimization; (8) development and testing of efficient optimization methods; (8) sensitivity analyses; (9) Uncertainty Quantification for Design;(10) LO issues in MDO as constraints and performance functions; (11) System Modeling and Discretization for Design, (12) Multi-Fidelity Analysis for Design.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B0129: High-Fidelity Multidisciplinary Computational Fluid Dynamics

Visbal, M.

(937) 713-7058

We conduct basic and applied research in multi-disciplinary high-fidelity computational fluid dynamics, a technology that is critical to the effective development of future Air Force systems. Mutually beneficial collaborations are sought in a broad range of research activities with the main objectives of advancing the state of the art, and complementing and/or expanding in-house capabilities. Opportunities for focused-research include (but are not limited to) the following topics:

(1) Development of high-order computational approaches, including structured and unstructured high-order spatial schemes, high-order implicit time-discretization methods, improved boundary treatments, as well as procedures for accurate solution of aero-acoustics and flows containing both fine-scale and sharp features (e.g. compressible turbulence).

(2) Simulation and improved understanding of vortex flows relevant to maneuvering combat unmanned air vehicles (UCAV) and small unmanned air vehicles (UAV) with emphasis on transition effects, dynamic stall and leading-edge vortex formation and breakdown, wake structure, and unsteady loads (e.g. gust).

(3) Direct (DNS) and Large-Eddy simulation (LES) of transitional and turbulent compressible flows, including improved sub-grid-stress models, inflow conditions for LES, and hybrid RANS/LES approaches extendable to complex configurations.

(4) High-fidelity simulation of active flow control of external and internal transitional, separated and vortical flows employing both traditional and novel techniques (e.g. synthetic jet and plasma-based actuators).

(5) Development of a high-fidelity computational framework for the analysis of aero-optical aberration in the near-field encountered in tactical laser weapon systems. Assessment of the role of aberrating flow structures on overall optical distortion pattern for relevant canonical flows. Investigation of flow control strategies to either regularize or break up large-scale coherent turbulent structures in order to mitigate overall aberration and enable/guide adaptive optic techniques.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B3817: Unmanned and Micro Air Vehicle Guidance, Control and Dynamics

Kingston, D.

(937) 255-6301

We are committed to the aggressive development and transition of advanced air vehicle control technology to industry and the war fighter to improve total weapon system lethality, survivability, agility, performance, and affordability. Our long-term objective is to develop adaptive and autonomous control theories for the advancement of future Air Force flight vehicles.

Our current research focuses on autonomous and cooperative control of multiple unmanned air vehicles, flight control of flexible wing small UAVs, guidance and control of air-breathing hypersonic vehicles, and verification and validation of flight critical software. Specific research areas include (1) multi-objective optimization for cooperative mission planning involving heterogeneous unmanned vehicles interacting with one or more human operators; (2) cooperative ISR (intelligence, surveillance, and reconnaissance) techniques for multiple vehicles to locate, identify, and track dynamic targets; (3) cooperative strategies for multiple, heterogeneous unmanned air vehicles performing coupled tasks, including the effects of realistic network communication systems such as network latency and delays that result in different target state information on different parts of the distributed decision and control system; (4) autonomous and intelligent control algorithm development, including algorithms with the ability to learn improved responses to a dynamic environment; (5) control oriented modeling of flexible wing small UAVs; (6) control law development for small UAVs that use unsteady aerodynamic and mass property based control effectors; (7) experimental testing and validation of control laws for flexible wing small UAVs; (8) control law and trajectory generation for ground operation of small UAVs while perched, recharging, or operating as a ground based surveillance platform; (9) development of guidance and control laws for air-breathing hypersonic vehicles that provide optimum maneuvering performance while accommodating engine operability and aerodynamic heating constraints; and (10) flight control algorithms for hypersonic vehicles that prevent departure from controlled flight during inlet un-start. Our goal is to develop and validate control algorithms through real-time, nonlinear simulations and experiments, and transition technology to benefit the war fighter.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B4614: Active Flow Control Modeling and Development

Tilmann, C.

(937) 656-8782

Recent developments in small, powerful, and efficient flow control devices have made the application of active flow control systems on future aircraft a viable alternative. Modern flow control effectors and techniques show promise for localized adaptive control of boundary layer separation, laminar to turbulent transition, shear layer turbulence, and secondary flow features. They may also be used to create ‘virtual’ aerodynamic surfaces that can be tailored for changing operating conditions, or to provide flight control. To effectively use these devices in a system requires a multidisciplinary approach that includes further research in sensors, fluids, and adaptive control technologies. We must first acquire knowledge of the base flow to be modified, and determine which flow effectors can most efficiently modify it. We must also determine what flow properties can be sensed in a practical way, and how this information can be used to indicate the state of the flowfield. Then controllers to interpret sensor information, and direct the flow control effectors, can be developed.

Areas of interest include (1) new flow control methods and actuator devices with expanded frequency range, greater amplitude, and improved adaptability; (2) control systems that optimize performance in specific applications; (3) numerical simulation and experimental validation of devices to enhance understanding of the relevant flow physics; (4) integration of existing devices into air vehicle systems; (5) laminar to turbulent transition modeling, prediction, & control; (6) flow control enabled flight control; (7) aero/structure/controls interactions; and (8) development of rapid flow control modeling methods that allow designers to utilize the technologies in design trade studies. Research could involve developing new flow control methodologies, data base development, computational modeling, analytical modeling, and/or software integration.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B4615: Hypersonic Boundary Layer Transition and Control

Kimmel, R.

(937) 255-8295

Boundary layer transition from laminar to turbulent flow impacts hypersonic vehicle performance more profoundly than low-speed vehicle performance as a result of the detailed inter-relation of systems on hypersonic vehicles. Accurate prediction is difficult because of the sensitivity of transition to initial conditions. Although computational tools continue to improve, their use is limited largely to specialists. Ground testing continues to be a valuable tool; however, boundary layer transition is one of the most difficult fluid dynamic phenomena to replicate experimentally. It is relevant to such proposed systems as transatmospheric, future strike, and reconnaissance vehicles.

Basic research opportunities exist in the prediction of hypersonic boundary layer transition. Areas of interest include (1) linear stability parabolized stability equations, (2) computation of basic states for three-dimensional flowfields, (3) stability calculations for three-dimensional flowfields, and (4) hypersonic stability and transition measurements.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B4616: Energy-Based Methods for Integrated Aerospace Systems Analysis & Design Optimization

Camberos, J.

(937) 713-7151

Aircraft have evolved into extremely complex machines, posing a highly integrated design challenge. Some of the systems also generate by-products in the form of heat that must be carefully addressed. Methods exist for the design of all these systems based on evolutionary vehicle development. However, the more we depart from existing databases and experience levels, the less confident we are in an optimal design. In addition, many of the classical techniques remain constrained by the simplifying assumptions of quasi-steady, quasi-equilibrium, etc. If these assumptions are not considered, there is no guide as to when those classical techniques no longer give an energy-optimal solution. In particular, the total system and all its components need to be designed in the same energy-based framework. To realize the full potential of these new methods, they must allow design of all the aircraft subsystems to common system-level optimization criteria. Fundamental challenges remain that must be solved before such a vehicle becomes an affordable reality. The following are samples of the required research:

(1) Computational Capability for Loss-Analysis of Aerospace Vehicles. A coupled solution to the Second Law of Thermodynamics and the Navier-Stokes equations needs to be accomplished. Our primary focus will enable the analysis of configurations in terms of entropy generation (exergy destruction) in the wake in order to facilitate numerical experimentation. Theoretical analyses of minimum induced drag based on entropy generation will be studied and confirmed. We will assess the exergy balance of active flow control concepts, especially requiring energy input to the flowfield. In addition, a common framework will be defined for every aspect of vehicle design in exergy terms. It will be shown that mission and vehicle system requirements can be stated in terms of work to be done using the exergy (work potential) of the fuel. This computational capability in a system-level design framework will facilitate the discovery of revolutionary concepts able to achieve maximum performance per amount of work expended.

(2) Structures as an Energy Subsystem. Conventional high-speed vehicles are required to protect the structure from elevated temperatures or provide active cooling, a simple form of energy transfer. Current efforts utilize structural deformation as a flight control effector (i.e., wing twist for roll control), which requires actuation power. In hypersonic vehicles, the structure will have to be a fully integrated part of the system. In these vehicles, the structure may distribute energy between other subsystems, it may store energy for use as and when required, and it may be a user of exergy for tailoring different characteristics. For the future, with the advent of active structures technology, we need to understand the vehicle structure as an energy subsystem.

(3) Propulsion as an Energy Subsystem. In current aircraft, the engine obviously supplies the direct power and cooling air for all the aircraft subsystems. The definition of a jet engine as an energy component with airframe weight and drag has been done. A plasma-based vehicle will require new forms of propulsion/airframe integration. We need to understand how the hypersonic propulsion system, the various plasma-generating devices, and other subsystems can be designed to common metrics and optimization criteria based on the exergy/entropy analysis methods.

(4) Optimization Techniques for a System of Energy Systems. Conventional optimization techniques are not guaranteed to be the most appropriate for the envisioned system of energy subsystems. We must understand how to minimize total potential work loss in a complex integrated system subject to the appropriate constraints.

(5) Control Strategies for Energy Systems. A conventional flight control system is a user of exergy in the form of actuation power, and has an impact on vehicle drag, which consumes exergy. There are also multiple subsystems involved in the total vehicle control system, subject to (1) above. Now, the magnitude of the control design problem is magnified when we consider the control requirements and associated subsystems of future vehicles. First, we need to understand how the total vehicle control system can be designed to energy-based principles. Second, we need to understand how to control the distribution or transfer of energy between the different subsystems in order to produce an optimum system design.

Key Words: Systems integration, energy-based analysis, exergy-based methods, multidisciplinary systems analysis and design

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B4617: Computational Nonlinear Aeroelasticity

Beran, P.

(937) 713-7217

Through numerical modeling, we are studying the nonlinear, physical interactions that can occur between fluid and structure, with application to the transonic, hypersonic, and high-altitude flight regimes. Phenomena of interest include limit-cycle oscillation, control-surface reversal, and flutter. The purpose of the work is to develop new design methodologies not limited by the assumption of linearity. By constructing new design techniques that account for aerodynamic and structural dynamic nonlinearities, costly aeroelastic problems may be avoided at the preliminary design level. We are developing these new techniques with a two-fold approach. First, we hope to understand a physical interaction in order to determine what level of modeling is required to capture accurately the phenomenon. Second, we hope to formulate new, highly efficient, algorithmic procedures by which the phenomenon can be simulated in a design environment. We are currently developing new reduced-order modeling techniques and investigating models of varying fidelity. We will apply these procedures to the design of flexible wing configurations impacted by nonlinear physical processes.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B4943: Computational Aeroelasticity and Fluid/Structure Interaction

Gordnier, R.

(937) 713-7105

The need to expand flight envelopes and mission requirements for existing aircraft, and the design of new highly flexible and maneuverable aircraft has driven interest in developing nonlinear aeroelastic analysis capabilities. Research opportunities focus on the simulation of complex fluid/structure interactions. Emphasis is placed on coupling high fidelity, nonlinear, fluid dynamics solvers with nonlinear structural mechanics. These simulation techniques will be used to investigate the response of flexible aircraft structural components to unsteady aerodynamic loadings and maneuvers. Research topics include (1) the development of algorithms to solve the nonlinear structural dynamics equations coupled with fluid dynamics equations; (2) applying computational tools for detailed investigations of fluid/structure interaction problems, including buffet phenomena, flutter, limit cycle oscillations, unsteady maneuvers and gust interactions; (3) novel techniques for grid deformation and fluid/structure interface treatment; and (4) development of multidisciplanary fluid/structure algorithms appropriate for a massively parallel computing environment.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B5739: Computational Fluid Dynamics Research in Numerical Simulation of Turbulence Flows

Rizzetta, D.

(937) 713-7104

Research opportunities exist to examine complex flow situations, employing direct numerical simulation(DNS) and large-eddy simulation(LES) in order to represent turbulent structures. Problems are considered which have both fundamental scientific and practical significance. Current efforts focus on developing high-order numerical procedures employing implicit LES techniques, as well as solutions of the Favre-filtered Navier-Stokes equations. For the later, improved subgrid-stress modeling is sought. Recent applications have been devoted to plasma-based flow control for low-Reynolds number airfoils and wings. Previous efforts have included simulation of supersonic compression-ramp flows with shock waves, acoustic suppression of aircraft weapons bay cavities using flow control, investigation of transitional flow past low-pressure turbine cascades, and roughness generated transition. We also have interest in applying the Reynolds-averaged Navier-Stokes(RANS) approach for practical computations. For this purpose, two-equation models and Reynolds stress formulations have been considered. Hybrid turbulence models for unsteady RANS applications and detached-eddy simulation(DES) are also being examined.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B5740: Computation of Supersonic and Hypersonic Flow Phenomena and their Control

Poggie, J.

(937) 713-7061

Improved supersonic flight and space-access capability with air-breathing hypersonic trajectories are key elements of many future technology development programs because of their profound impact on commercial and military activities. Significant basic research challenges remain to be overcome in these areas, ranging from developing theories of transition and turbulence to predicting and managing the aerothermal and propulsion environment and determining non-continuum effects. Given the daunting difficulty of reproducing flight conditions in ground-test facilities, simulations necessarily have an integral role to play in design and development. High-fidelity computations of high-speed flows are very challenging because of the fundamentally multidisciplinary and three-dimensional nature of the problem. In addition to viscous fluid dynamics, it is often essential to consider turbulence and thermo-chemical non-equilibrium effects such as vibrational excitation, dissociation, ionization and combustion. Successful and affordable long-range hypersonic flight will also require breakthroughs in the understanding and implementation of revolutionary concepts such as plasma-based flow control. Formulations must therefore be extended to include variants of the Maxwell equations and sophisticated plasma models. The combined phenomena yield a large, stiff set of non-linear governing equations, which must be resolved with fine spatio-temporal discretizations. It is essential therefore to develop highly accurate physical models, and to couple them to advanced, robust numerical methods which can exploit massively parallel modern computational systems. Towards this end, broad research opportunities exist to (1) develop and implement highly accurate algorithms for a hierarchy of theoretical models of increasing fidelity with and without the continuum approximation, (2) utilize computational tools to investigate a variety of physical phenomena, including direct numerical simulations of supersonic and hypersonic transition and turbulence, plasma behavior in the aerospace environment and shock/boundary layer interactions, (3) develop, implement and validate models for state-to-state kinetics (4) explore drag reduction and thermal protection techniques through flow control.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B5741: Numerical Simulation of Glow Discharges for High-Speed Flow Control

Poggie, J.

(937) 713-7061

The possibility of electromagnetic control of high-speed flow was first considered in the mid-1950's following the discovery of the high levels of ionization present during atmospheric reentry. Although this technology has been examined by a number of research groups during the intervening decades, practical implementation of the concept has remained ellusive. Recent advances in the production of very strong magnetic fields and in the generation of atmospheric pressure plasmas have led to a resurgence in interest in the technology, and the Air Force Research Laboratory Computational Sciences Center has developed computational tools for modeling candidate flow control technologies (Poggie and Gaitonde, 2002). In particular, recent study has focused on glow discharges immersed in high Mach number gas flows, including the effects of strong applied magnetic fields. In support of this activity, the following research opportunities exist: develop new, high-fidelity numerical algorthms for modeling these discharges, incorporate improved physical models in existing numerical codes, and utilize existing computational tools to explore potential electromagnetic flow control technologies.

J. Poggie and D. V. Gaitonde, "Magnetic Control of Flow Past a Blunt Body: Numerical Validation and Exploration", Physics of Fluids, Vol. 14, No. 5, pp. 1720-1731, 2002.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B5742: Enabling Robust and Durable Aerospace Structures for Combined, Extreme Environments

Chona, R.

(937) 656-8793

We are aggressively pursuing a computational framework for enabling high fidelity simulation of structures exposed to combined extreme environments. Examples include reusable vehicles exposed to launch, sustained hypersonic velocities, and atmospheric re-entry and stealth aircraft with buried engines and ducted exhaust. Scientific challenges include the nonlinear coupling between extreme environment/loads and the structural response, evolving material attributes and interacting failure modes that define the structural limit state, and the computational framework to support a future paradigm shift towards structural scale simulation. The framework must allow the limit state and material attributes to evolve and interact with the structural response as the simulation progresses. The long-term goal of the simulation is to predict with high confidence the life of a structure subjected to a combined fluid-thermal-acoustic-mechanical-vibratory environment throughout a high-performance aerospace vehicle trajectory.

To support the long-term goal, we have challenges spanning the disciplines of mathematics, computation, and engineering. Exciting research opportunities exist in the areas of (1) computational structural scale simulation for developing the necessary algorithms and data structures required for efficient parallel computing in support of long time record simulations, (2) methods and algorithms for variable fidelity modeling including a priori and/or a posteriori error estimators with convergence indicators, (3) fluid-acoustic-thermal-structure solver integration focusing on the stability and fidelity for loosely versus fully coupled solvers, (4) multiscale coupling techniques addressing and the computational algorithms for spatial and temporal issues associated with the inclusion of fine scale features into a coarse scale model supporting high fidelity simulations, and (5) identification of representative or benchmark extreme environment structures with levels of combined loading targeted toward exercising specific phenomena for verification and validation of multi-physics simulations.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B6110: Design, Measurement, Modeling, Analysis, and Control for Optimal Weapon Integration

Stanek, M.

(937) 656-8767

The addition of turrets, pods, external stores and tanks, and weapons bays to advanced air and near-space military flight platforms are required to turn these flight assets into practical weapon systems. Unfortunately, these additional features can compromise the overall weapon system performance, due to undesirable effects on unsteady aerodynamic loads, turbulence properties, heat transfer rates, optical signal transmission characteristics, and other factors. Advanced diagnostic techniques, computational analysis, flow control, and advanced modeling are all tools which need to be developed and aggressively applied to integrate advanced weapon concepts on future platforms.

The two classes of weapon integration which are currently of most interest are weapons bays and optical apertures (for directed energy). Basic research opportunities include, but are not limited to the following areas: (1) design, analysis, and modeling of flow control devices to improve baseline integration characteristics; (2) optimization of the combination of aerodynamic shaping and flow control for best performance of the integration; (3) improvements to boundary conditions, turbulence models, physical effects models, and other specific computational aspects to enhance accuracy, fidelity, speed, and usefulness of advanced simulations; (4) the study of dynamic control techniques timed to the release of a store, to enhance trajectory properties; (5) modification of stability properties, turbulence properties, and separation characteristics of shear layers associated with cavities, turrets, or other integrations of interest; (6) development of models for prediction or scaling of flow control devices, and (7) development / use of innovative diagnostic techniques to allow for visual study as well as quantitative description of integration properties with and without flow control. Research could involve analytical modeling, computational simulation, design, experimental simulation, software development, or some combination of all the above.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B6113: Design and Life Prediction Tools for Aircraft Structural Components with Engineered Residual Stresses

Langer, K.

(937) 656-8814

The introduction of engineered residual stresses (ERS), through processes such as laser peening and low plasticity burnishing, has been found to enhance the fatigue response of aircraft structural components, with attendant benefits of increased safety, reduced operational costs, and improved performance. However, for full exploitation of these technologies, there is a need for validated analysis methods by which the effects of ERS on design life of replacement and existing components can be predicted and studied. A validated analysis methodology will enable more cost effective developments of ERS solution options by reducing the amount of experimental iteration required to field new applications. Further, such methods will allow designers to optimize ERS treatments for specific objectives, as well as study the effects of error and uncertainty.

To meet these objectives, research opportunities exist in the area of design and life prediction for ERS-enhanced aircraft structural components. ERS treatments of interest include but are not limited to laser peening and low plasticity burnishing. Specific topics include:

(1) Development of validated analysis techniques and design tools for predicting the fatigue response of ERS-enhanced components under spectrum loading, including realistic initial conditions such as prior fatigue exposure, shot peening, and/or manufacturing-induced residual stresses.

(2) Development of stochastic analysis techniques for quantifying the effects of input uncertainties, such as laser parameters or material response, on the predicted fatigue response of an ERS-treated component.

(3) Development of validated damage tolerance analysis methods for aircraft structural components to study the effects of ERS on fatigue crack propagation. Fatigue life prediction models should account for residual stress redistribution, work hardening, and/or surface deformation due to ERS treatment.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B6114: Unsteady Aerodynamics and Aeroelasticity for Micro Air Vehicles

Ol, M.

(937) 713-6650

Unsteady aerodynamics is relevant when there is no reference frame in which the bulk flow relative to a body is time-invariant. This is encountered in essentially all flight modalities, but is of principal import for Small Unmanned Air Vehicles (SUAVs), which encounter strong flow separation and large transients. While the development of practical SUAV flight articles has been spurred primarily by improved components (sensors, batteries, actuators, onboard processing, materials and so forth), progress towards highly maneuverable, gust-tolerant, hover-capable SUAVs rests upon advancement of fundamental knowledge in flowfield history, the resulting aerodynamic loads history, and the interplay with structural flexibility.

We are less interested in aeroelastic optimization or in multi-disciplinary design, than in understanding the constituent physics using abstracted problems. Recent work has ranged from airfoil boundary layer developed forced by imposed motions such as pitch/plunge/surge, to flat-plates in 2D and 3D undergoing periodic or transient accelerations with or without a free-stream, to bio-inspired problems of flexible wings undergoing articulated motions. Though a wealth of data has been amassed, basic questions remain nebulous. For example, when is a spring-mass-damper analogy sufficient to describe the lift/thrust/pitch history for a rigid flat plate in two dimensions, if the motion amplitudes/frequencies are not limited to a linearizable range? With decreasing Reynolds numbers the aeronautical engineer has more and more reason to consider biomimetic approaches based on the flight of insects, humming birds and bats, adopting nature's solution to cruise efficiency, flight agility and gust tolerance. But rational use of such approaches is predicated on rigorous study of the relation between the kinematics of flight-surface motions, the time-dependent aerodynamic and inertial loads, the mutual effect of loads on structural deformations, and the flowfield dynamics. This includes phenomena quite outside of the scope of traditional aeronautical engineering, such as manipulation of shed vortical structures to increase lift and thrust, and the phasing of vortex shedding to provide aerodynamic moments for maneuvering or gust rejection.

Areas of interest cover computations, experiments, and classical analytical methods of unsteady aerodynamics, for Re ~ 1000-50,000. Ideally, one would amalgamate all three approaches, drawing on the respective strengths of each. For, example, high-resolution computations are adept at capturing fine details of boundary layer evolution, while particle image velocimetry can track and identify bulk coherent vertical structures in complex separated flow. For computations, Direct Numerical Simulations are both tractable and necessary: tractable, because the Re is in some cases sufficiently low; and necessary, because the first-order coupling of laminar to turbulent transition and the complex mechanisms of vorticity production and transport invite a methodology completely free of subgrid modeling. At the same time, rapid exploration of SUAV design parameter space requires a fast, lower-order approach, such as a suitably tuned 3D viscous vortex particle method. Experiments, either with abstracted configurations such as oscillating plates/airfoils or with “biomimetic” configurations, have yielded a wealth of information on nature's approach to flight. It is necessary to bridge traditional unsteady aerodynamics with the newly discovered phenomena via careful experiments using modern flowfield diagnostics. Both experiments and computations need to address the flexibility of lifting surfaces, with proper aeroelastic scaling for wind tunnel/water tunnel models, and coupled fluids/structures numerical codes. The eventual goal is a robust but low-order model of the complete vehicle state, useful for flight dynamics, control, and vehicle design.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B8576: Energy Harvesting Applications and Development

Reich, G.

(937) 713-7138

Energy harvesting (EH) is a critical function for future aircraft systems. Fuel savings, alternative energy, noise and air pollution concerns, range and endurance extension, among others, all contribute to the desire for harvesting ambient or waste energy from the system or from the surrounding environment. Vehicles as diverse as small unmanned air vehicles, high altitude, long endurance platforms, and re-entry or very high-speed systems all have clear system-level benefits from the addition of energy harvesting technologies. While the particular technologies that make sense in any application depend on the system under investigation, it is clear that a at least one characteristic is common to all of these technologies. This is that the technology must be an integral part of the multifunctional system, and not exist separately as a "parasitic" component. As an example, the integration of antennas into load-bearing structures has created a need for thermal harvesting to also be integrated into the structure in order to dissipate waste heat and reduce the size and weight of the multifunctional system.

Research opportunities in this area are not necessarily focused on a particular EH technology. To date, we have been more focused on the integration part of the equation:

(1) How can the EH solution be incorporated into structure;

(2) Where on the vehicle are there signficant energy sources that can be tapped into;

(3) What form does the harvested energy take and how can it best be utilized elsewhere in the vehicle;

(4) What is the impact of the technology on the rest of the system, and how can the system be modified to best make use of or improve the efficiency of the technology.

Keywords: energy harvesting, energy conversion, vibration, thermoelectric, solar, multifunctional structures

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B8577: Morphing Aircraft Structural Technology Development

Reich, G.

(937) 713-7138

Morphing aircraft is by AFRL's definition a vehicle that can achieve large-scale changes in vehicle shape, such as 50% change in wing planform area or 100% change in wing span. This variation allows a vehicle to perform radically different mission segments at near-optimal conditions, and gives mission planners and commanders on the ground increased flexibility in the types of missions that can be completed with a single vehicle type. Morphing as a technology spans the entire range of vehicle size and speed scales, from super- and hyper-sonic systems down to small unmanned air vehicles. An opportunity exists for basic research in morphing aircraft structural technology development to support the Air Vehicles Directorate's Adaptive Structures Team. Our research in morphing aircraft is focused in several areas: the integration and distribution of actuation into a structure in order to effectively move the structure using minimum energy; the design of novel structural layouts and mechanization concepts using topology optimization schemes tied to linear and nonlinear structural analysis; the development of viable morphing structural skin concepts that allow large motions to occur with minimum resistance, while maintaining outer mold line integrity for development and transfer of aerodynamic loads; and the application of morphing technologies to small unmanned air vehicles.

Keywords: topology optimization, morphing aircraft structures, flexible skins, nonlinear structural mechanics, small unmanned air vehicles, adaptive structures

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.00.B8578: Multifunctional Structural Antenna Concept - Modeling and Simulation

Zeppettella, D.

(937) 255-4277

The number of antennas on all air vehicles is increasing rapidly, as the need for larger antennas and large antenna arrays are necessary to meet range, and directivity requirements. As a result the installation of antennas with the airframe is becoming an important performance, cost and structural integrity consideration. Current antenna installations are limited to parasitic non-load bearing RF systems with radomes that protrude into the air stream and increase signature, drag, and supportability costs, or require complex support structures and integration schemes that add manufacturing cost and weight. The advent conformal load-bearing antenna structures (CLAS) technology presents a convergence of the structural and avionics disciplines. The multidisciplinary nature of this technology requires that researchers tackle the challenge of development in a truly collaborative fashion. This research topic is directed at modeling and simulation of advanced structurally integrated phased array structural antenna systems. Specific focus should be directed at the ability to develop an architecture that can be electrically reconfigured to provide wideband performance. Concepts to be explored should consider the use of RF MEMS devices, novel metamaterials along with the constraints associated with integration into a lightweight load bearing architecture. Modeling should provide accurate representation of the structural material electromagnetic interactions, losses associated with devices, and the conductive and dielectric materials. Analytic results should be validated based on the literature and from empirical testing conducted at AFRL where structural, S-parameter and near field chamber data will be developed.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.08.B6657: Sensitivity Analysis and Uncertainty Quantification for Multidisciplinary Systems Analysis & Design Optimization

Camberos, J.

(937) 713-7151

Co-advisor:

Beran, P.

(937) 713-7217

philip.beran@us.af.mil

Multidisciplinary design and analysis integrates components from various disciplines to synthesize aerospace systems. Modern design techniques are emerging that optimize the system as a whole rather than as individual components. This makes the entire optimization problem quite large and may consist of libraries of variables, constraints, and competing performance criteria. As multidisciplinary analysis and design methods evolve, primarily with the use of modern computer capabilities, we must account for cascading uncertainties in the various modeling and simulation tools for each discipline. Research opportunities exist in the general area of uncertainty quantification and sensitivity analysis for systems analysis and design optimization. Topics of interest include (1) Methods for quantifying uncertainty in selected disciplines (primarily fluids, structures, electromagnetics, electromagnetic-gasdynamics, and controls); (2) The propagation of uncertainty within a discipline and across disciplines; (3) Control and reduction of uncertainty; (4) Verification and validation methods and techniques for the modeling and simulation tools used in selected disciplines; (5) Application of Design of Experiment techniques for modeling and simulation; (6) Efficient methods for calculating the sensitivities of key parameters in selected disciplines; (7) the impact of uncertainty on system robustness, reliability, and risk in context of each discipline and in multi-scale and multidisciplinary analysis and design.

Key Words: MDAO, uncertainty quantification, uncertainty propagation, sensitivity analysis

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.13.B1221: Multiscale Modeling for Aircraft Thermal Management

Patnaik, S.

(937) 656-5452

Research opportunities are available in multiscale modeling of heat transfer, conversion, and storage for thermal and energy systems with special emphasis on computational methods for improving the understanding of nano- and microscale transport phenomena. Specific fundamental problems of interest are enhancement of heat transfer at multiphase interfaces by controlled evaporation and condensation by tailoring solid surface characteristics (roughness and hydrophobicity) and liquid characteristics (presence of surfactants); microscopic behavior of solid-liquid contact phenomena; and heat transfer in phase change materials. Some current investigations focus on molecular modeling of nanoscale heat transfer in composite materials, mesoscale modeling of fluid structure interactions and its effect on fluid transport, multiscale-multicomponent modeling of enhanced heat transfer of phase change (boiling and evaporation), numerical modeling of open cell foam and microscale heat transfer for phase change materials for energy storage, energy conservation studies in vapor cycle refrigeration systems, and development of predictive thermal modeling and simulation tools to address phenomena at different length and time scales. Applications of interest are in the broad area of active and passive energy management for aircrafts and high power electronics, with a focus on advanced heat transfer, energy storage, and high efficiency cooling technologies for transient thermal management.

*References:

Patnaik SS, Mesfin T: Modeling and Simulation of Nanoscale Materials, in Nanoscale Multifunctional Materials: Science and Applications. Edited by Mukhopadhyay S. John Wiley & Sons Inc, 2011: 175

Hendrik H, et al: Modeling of Polymer Matrix Nanocomposites, in Modeling and Simulations in Polymers. Edited by Purushottam D, et al. Weinheim (Germany): Wiley VCH Verlag GmbH & Co. KGaA, 2010: 37-92

*Keywords:

Multiscale modeling; Nanoscale thermal transport; Thermal management; Thermal energy storage; Phase change heat transfer; Molecular modeling; Thermal modeling

*Eligibility:

Citizenship: Open to U.S. citizens and permanent residents.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.14B0847: High Performance Electric Actuation System Thermal Management

Leland, Q.

(937) 255-3060

This topic focuses on research and development of aircraft High-Performance Electric Actuation System (HPEAS) technologies. Specific areas include thermal management (TM) of electromechanical actuators (EMA) and motor control electronics; novel design concepts of compact, lightweight, jam free, or fault tolerance EMAs; innovative electric power management of peak and regenerative power; prognostics and health management technologies; and modeling and simulation tools for HPEAS mission analysis and technology assessment. For TM, any solutions, liquid or air or other heat transport medium, active or passive, should be integrated with the actuation system as well as with the aircraft electric power system and air vehicle structure. For example, when implementing an air cooling solution, its heat sink requirement and electric power input should be in agreement with the aircraft’s flight envelope. The ultimate goal of this topic is an optimized HPEAS design fully integrated with thermal management solution and electric power system in an aircraft environment.

HPEAS is one of the three critical technologies being developed under AFRL/Aerospace Systems Directorate’s INVENT program. HPEAS offers considerable advantages over conventional hydraulic actuation system for air vehicles. Three technical challenges have to be addressed for a successful transition of EMA to aircraft flight critical control actuation: thermal management, fault tolerance, and peak and regenerative power management. EMA and its electronics operate under harsh environments, especially those for primary flight control and propulsion system controls for military fighter aircraft. Its environmental temperature ranges from -40o C to 125o C, its heat loads are highly transient and localized, making thermal management one of the critical challenges for HPEAS. The dynamic power level, both peak power draw and regenerative power, also poses a great challenge for the aircraft electric power system. Reliability or fault/jam tolerance has to be proven as good as conventional hydraulic actuation before its acceptance to primary flight control.

Keywords: Thermal management; Electromechanical actuator; HPEAS; Electric actuator; EMA; Power electronics cooling; Motor cooling; Modeling and simulation; Aircraft actuation; Regenerative power

*Eligibility: Citizenship: Open to U.S. citizens and permanent residents.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.05.14B0848: High Capacity, Advanced Battery Development

Miller, R.

(937) 255-2880

Next generation aircraft contain a host of system-level power and thermal challenges to enable capabilities such as: low-observable electronic attack and electrically-driven directed energy-based self-defense. Energy storage is among the critical technology challenges supporting aircraft power and directed energy weapons (DEWs). To this end, AFRL has the goal to develop a high capacity, advanced battery capable of operation as both an abuse tolerant, high-rate power dense source while maintaining high energy storage capability safely across a wide-temperature range. Current efforts focus on work, ranging from: the development of high capacity cathode materials for solid-state Li batteries; novel film processing techniques for the fabrication of solid-state batteries and fuel cells; power management/hybridization technology for small unmanned aerial vehicles (S-UAVs) and portable soldier power; and aircraft/DEW battery characterization and analysis.

The objective of this effort is to investigate methods for developing high capacity, advanced batteries for traditional aircraft and S-UAV applications. Solid-state lithium batteries have gained considerable interest as a next generation high energy-dense electrochemical power source. They offer not only the potential for high energy densities but also safe operation as compared to state-of-the-art Li-ion battery technology. In practice, the performance of these batteries falls drastically short of the potential theoretical values due to limitations in cathode diffusion/reaction kinetics and instability/decreased conductivity issues in the electrolyte. Advancing beyond these limitations is a function of two important but equal aspects: development of high capacity, safe cathode materials and introduction of novel cell processing/fabrication techniques.

Research interest includes exploring alternative novel cathode materials and utilizing advanced film processing techniques (ink jet and aerosol jet printing) to fabricate all solid-state cell configurations. In addition, energy and power densities in batteries typically have an inverse relationship, making it unlikely that one battery can provide both. Therefore, there is an interest to explore hybridizing different battery chemistries to produce an overall hybrid battery pack which can provide both high power discharge capability while maintaining high energy density storage.

Eligibility: Open to U.S. citizens and permanent residents

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B0100: High-Speed Propulsion

Hagenmaier, M.

(937) 255-7325

We conduct research on ramjet/scramjet and mixed-cycle propulsion components applicable to supersonic and hypersonic flight regimes. This includes fluid-dynamic studies of inlet, combustor, and nozzle components. We also pursue development of efficient computational methods, turbulent models, and kinetic schemes for reacting, high-speed flows. Our research approach necessitates the integration of experimental and theoretical methods to address challenges in (1) turbulent transport, entrainment, and mixing of multistream flows and/or two-phase flows including fuel injection, atomization, droplet transport and evaporation, flame stabilization, and blowout limits; (2) nonintrusive, multidimensional diagnostic instrumentation and concepts, including hardware and software, for applications to realistic combustor flow environments; and (3) time-averaged and time-dependent computational-fluid-dynamics codes for flow and combustion simulations in complex geometries. Available equipment includes extensive computer facilities (mini's to high-speed, mutiprocessor supercomputers), two combustor thrust rigs, a research combustor designed for a wide range of operations and applications of laser diagnostics, and a spray tunnel facility with associated optical and conventional diagnostic equipment. Also available is a stand-alone supersonic flow research facility, specifically designed for nonintrusive probing of the supersonic flowfield for simultaneous field measurements of pressure, temperature, velocity, and species concentration.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B0101: Combustion and Spray Studies and Diagnostic Development

Gord, J.

(937) 255-7431

This research addresses the physics and chemistry of processes in gas turbine combustors and pulsed-detonation engines through the study of isolated and interacting droplets, sprays, jet premixed and diffusion flames, swirling flames, and bluff-body stabilized flames. Continuing work requires experimental and theoretical approaches related to the following: (1) turbulent transport, mixing, entrainment, evaporation, droplet drag, drop-spacing effects, atomization, finite-rate chemistry, flame stability, ignition, and blow-out; (2) development of laser-based diagnostic techniques to support combustion and spray experiments; and (3) studies using either time-averaged or large-scale, time-dependent simulations. Numerous well-equipped laboratories contain small- and large-scale combustion tunnels and advanced laser apparatus designed for two-dimensional imaging, coherent anti-Stokes Raman spectroscopy; laser Doppler anemometry; phase Doppler particle sizing; laser-induced florescence techniques; and femto/picosecond chemistry studies. Access to various combustion flow codes and the DOD ASC Major Shared Resource Center is available for theoretical studies.

Eligibility: Open to U.S. citizens and permanent residents

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B0102: Model Development and Validation Experiments for Aircraft Fuel

Edwards, J.

(937) 255-3524

Aviation fuels are not only the energy source for advanced aircraft; they are also used to cool airframe and engine components. Under high thermal loads, hydrocarbon fuels can react with dissolved oxygen or undergo pyrolysis to form gums and other deposits that reduce the efficiency of heat exchangers and cause fouling of fuel-system components. Computer models that can be used to estimate the thermal decomposition of hydrocarbon fuels in simple heat exchangers are in an early stage of development. The models are time dependent and include global chemistry, fluid mechanics, and thermodynamic effects. Many of the fundamental processes associated with thermal degradation of fuel are not well understood. One of the objectives of the models is to improve our understanding of selected issues in physics and chemistry. Of particular interest is experimental and theoretical research on the influence of dissolved oxygen content, turbulence, thermal loads, pressure, catalytic reactions, or heat-exchanger geometry on the thermal degradation of hydrocarbons found in jet fuels. Dedicated minicomputers and reacting flow codes are available for theoretical studies. This research includes current fuels (JP-5,7,8,10), as well as alternative (non-petroleum) fuels. Alternative fuels include those derived from coal or biomass through the Fischer-Tropsch process, as well as aviation fuels derived from oil shale and tar sands and direct liquefaction of coal. "Biojet" fuels, analogous to biodiesel, are also of interest.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B0103: Advanced Turbine Engine Lubrication

Rosado, L.

(937) 255-6519

This research focuses on developing advanced lubricants and related mechanical components (bearings, gears, and seals) required for turbine engines to power aircraft in the twenty-first century. We are developing novel mechanical and magnetic systems to minimize the weight and complexity of the traditional lubrication system. Finite element methods are used to model heat dissipation, stress fields, and shaft dynamics. We are currently interested in creating a graphical user interface to couple bearing analytical software codes with commercial FEA packages such as ANSYS. Continuing research in high-temperature lubrication addresses thermal-oxidative degradation; and tribological, toxicological, and environmental properties of candidate lubricants. World class facilities equipped with unique test equipment and instrumentation are available for analytical, simulation, oxidative-thermal degradation, bearing and gear performance, rolling contact fatigue, elastrohydrodynamic film, high-pressure viscometric, diagnostic, and magnetic bearing studies. Dedicated minicomputers, a Silicon Graphics Octane workstation, and finite element and tribological modeling software are available for theoretical studies.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B0104: Aero and Thermodynamics of Rotating Machinery

Sondergaard, R.

(937) 255-7190

An improved understanding of internal flows and heat transfer under non-steady conditions is necessary for the continued advancement of turbine engine performance. Shortcomings in the ability to accurately predict aerodynamics and heat transfer of cooled and uncooled components in the hot section significantly impacts the design and development cost of new engines and component performance and durability. Improvements in specific fuel consumption are largely related to the ability to increase turbine inlet temperature and cycle pressure ratio, which are limited by the ability to model these flows. Important research areas include internal and external cooling of vanes, turbine blades, shrouds, platforms, broach slots, and disk cavities. Also important is the understanding and control of the aerodynamics and aerodynamic losses associated with these components. Nearly all of these flows are three dimensional and unsteady, and must be characterized over a large range of operating conditions, including low Reynolds number conditions at which flow separations become major contributors to aerodynamic losses. Strong pressure gradients, density gradients, curvature, rotation, and compressive effects are present in many of these flows. Non-steady shocks and shock boundary layer interactions can also be important.

Of interest are experimental and computational investigations studying methods of increasing film cooling effectiveness, techniques for selectively increasing or decreasing heat transfer coefficients, methods of flow control to increase blade loading, reduce passage, hub and tip losses, and techniques for controlling aeroelastic effects and damping. Characterization of aerodynamic, thermal, and structural effects requires non-steady two- and three-dimensional computational schemes and experimental techniques. The spatial and temporal resolutions need to approach wall flow scales in order to provide the accurate time-resolved blade vane interaction effects, as well as resolve loss mechanisms and heat transfer associated with other non-steady secondary flow phenomena that are present. Specific computational interests are three-dimensional non-steady, multidisciplinary approaches that are capable of optimizing aerodynamic, thermal, and structural designs.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B0105: Diffuser/Fan Interaction Modeling and Simulation

Puterbaugh, S.

(937) 255-7432

A number of future aircraft platforms under study incorporate gas turbine propulsion systems that are embedded within the air frame. Further, the diffuser, which sits between the inlet and the propulsion system may be of serpentine or some other odd geometric shape. A diffuser with curved walls will generate secondary flow, which is likely unsteady, that will influence the behavior of the fan module of the engine. Complex total pressure distortion patterns in combination with significant flow angularity is expected to be present at the Aerodynamic Interface Plane. The Compressor Aero Research Lab (CARL) is pursuing a combination experimental and computational research program to determine the interaction effects of such a system. The ultimate goal of the computational part of the research is to fully model the unsteady fluid mechanics occurring within the diffuser and a full-annulus representation of the research fan stage. Disparate time and length scales of the two components make this a challenge.

There are two areas of the computational work of particular interest to the CARL effort. First is development and implementation of solver and turbulence modules that will interface with the in-house developed, object-oriented computational framework to provide a reliable computational tool for the problem at hand. Second is the development and implementation of co-processing tools for analysis and display of computational results generated by this grand challenge-scale computational effort. The in-house developed framework accommodates solver components for simulations ranging from 1-D analyses to 3-D RANS to LES to DNS. A number of reduced order and high-fidelity methodologies exist for the solution of the coupled inlet-propulsion system. It is desired to implement and compare a number of these methods within the framework – particularly unsteady RANS and LES –to promote consistency between solutions. This will also allow recommendations and best practices to be formulated. As simulation sizes increase, specifically for unsteady RANS and LES analyses, the amount of data available for 3-D flowfields has skyrocketed to > 1TB for many datasets. As such, it is incredibly important for some data reduction to occur during solver execution in order to eliminate the need to write excessive unsteady data. Capabilities are sought to meaningfully reduce the 3-D flowfields into manageable, analyzable extracts. Examples include particle tracking, accumulators (time-averaging and statistics), cut planes and isosurfaces, and feature detection (shocks, wakes, vortices). Successful implementation of the solver and co-processing capabilities will result in improved capability to quickly evaluate the efficacy of methods to capture coupling effects, distortion transfer, and relevant physics.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B0106: Computational Modeling for Advanced Concepts in Gas Turbine Engine Combustion

Sekar, B.

(937) 255-2668

Computational fluid dynamics (CFD) is becoming a powerful tool in the design and analysis of advanced air-breathing propulsion including conventional and unconventional systems. The latest improvements in numerical algorithms, geometric modeling, numerical discretization, grid generation, physical parameter modeling, and adaptability in the supercomputing environment (including parallel architecture), CFD tools are applied throughout the development process of combustion systems. The Combustion Branch of the Turbine Engine Division conducts research in interdisciplinary areas for gas turbine combustor flows. These areas include CFD, phenomenological physical modeling for turbulence for more accurate diffusion modeling, reduced reaction kinetics for hydrocarbon fuels, large eddy simulation techniques, turbulence-chemistry effects, multiphase flows, supercritical fuel technology, combustion aids and flame stabilization, and numerical acceleration schemes to improve convergence including solution adaptive techniques and unstructured grid technology. This research will emphasize numerical multi-dimensional analysis, reduced order analysis, analytical, computational, physical and numerical model developments including appropriate validations. Excellent computational platforms and high-speed graphic workstations are also available. The research will enhance our capability to design, analyze and optimize efficient combustion systems for turbo machinery.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B0112: Studies of Novel Combustion Concepts for Propulsion Systems

Schauer, F.

(937) 255-6462

AFRL's Combustion Branch plans, develops, and transitions basic research and applied technology development programs for military air-breathing engines. We do this by executing in-house and contracted programs that enhance the capability of turbo-propulsion systems through design, analysis, development, and test of advanced combustion systems. Additionally, the branch explores novel propulsion concepts critical to meeting future Air Force requirements. Some of these novel concepts include pulsed-detonation engines, inter-turbine burners, and trapped vortex combustors. The branch has in-house activities associated with these concepts.

The branch evaluates and enhances component capabilities through the understanding and innovative use of chemistry, aerodynamics, heat transfer, materials, diagnostics, computational fluid dynamics, and design tools. Areas of fundamental research include fuel injection, fuel-air mixing, fuel atomization, chemical kinetics, flame stability, supercritical fuel injection, flame dynamics and ignition phenomena. A growing focus area is the understanding the chemistry and combustion characteristics of alternative fuels for new propulsion systems. Well-equipped laboratory laboratories and computational resources are available to carry out the research activities. The laboratories can operate at sub-atmospheric to 40 atmosphere conditions, and include a host of intrusive and non-intrusive diagnostic capabilities.

Eligibility: Open to U.S. citizens and permanent residents

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B5437: Advanced Diagnostics for High-Speed Flows

Carter, C.

(937) 255-7203

This research addresses technologies essential to high-speed, air-breathing propulsion, including fuel-air mixing processes in subsonic and supersonic flows and the role of turbulent transport on mixing and combustion in high-speed flows. Objectives include the following: (1) incorporation of science into preliminary design and advanced development of ram/scramjet combustors; (2) development and application of accurate CFD tools for the design and analysis of ramjet/scramjet combustors; (3) development and application of advanced non-intrusive optical diagnostic techniques for high-speed reacting flows; (4) study of ionized flows on a confined supersonic flow, especially for enhanced combustion; and (5) transition of basic research ideas, concepts, and findings to exploratory development programs. In particular, three areas of focus are supported: (1) Fuel Control and Fuel Injection, wherein fundamental aspects are studied for gaseous, supercritical, and multiphase fuels; (2) Ignition, Flameholding, and Flame Propagation in Supersonic Flows, wherein fundamental aspects are studied with a view towards improving performance in a high-speed combustor; and (3) Multidisciplinary Laser Measurements for benchmarking modeling and simulation and for elucidating the physics of high-speed flows. Both laboratory-scale (e.g., the stabilization of attached and lifted turbulent jet flames) and large-scale (e.g., stabilization of flames within a supersonic combusting ramjet engine) experiments are employed. Facilities include extensive high-speed wind tunnels, where conventional and advanced diagnostics can be employed, and a well-equipped optics laboratory, where techniques and ideas can be explored in small-scale flows prior to being employed in the large-scale facilities.

Eligibility: Open to U.S. citizens and permanent residents

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B5438: Structural Dynamics of Turbomachine Components

Cross, C.

(937) 255-7231

For continued improvements in gas turbine engine performance and durability, a better understanding of the structural dynamics and vibrational response of airfoils, disks, and blisks is essential. Vibration of turbomachine airfoils and disks is a significant source of gas turbine engine failures and the need for both unscheduled and scheduled maintenance. Additionally, to meet the performance requirements of advanced gas turbine designs, new compressor designs tend toward airfoils with higher tip speeds, lower aspect ratios, more closely spaced airfoil rows, and fewer stages. These trends result in advanced components experiencing higher loading forces while having a reduced structural capability. The result is increased vibratory response and stress, leading to destructive high cycle fatigue failures. Our research goal is to assess life capability and vibrational characteristics of turbine engine components. Quantification of the capability of components under cyclic loading can reduce or even alleviate the need for costly repairs and diminish the possibility of failure.

Research areas in the study of airfoil and disk dynamics include investigation of mistuning in higher order modes, interaction of closely spaced modes, evaluation of inherent and added damping in airfoil systems, and integration of experimental results into prediction codes and FEM. Proposed research areas for improved bench experimentation include the development of simulated engine operating conditions (rotational forces, contact mechanics, component interactions), the development of innovative test techniques for component characterization, and the validation of advanced instrumentation techniques.

To support research in these areas, the Turbine Engine Fatigue Facility (TEFF) of AFRL's Aerospace Systems Directorate is available. The TEFF is a state-of-the-art research facility, which performs structural and vibrational evaluations of turbine engine components and subcomponents. The TEFF provides support to Air Force development programs through basic research and analysis in the areas of structural characterization, vibrational response, life prediction, and application of advanced measurement techniques. Experimental capabilities include scanning vibrometry, ping dynamic frequency analysis, travelling wave excitation, large-scale dynamic shakers, high-temperature ovens, and single and multiaxial fatigue test stands.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B5439: Injection and Flameholding in Supersonic Flows

Gruber, M.

(937) 255-7350

The success of a hydrocarbon-fueled scramjet depends on the ability of the combustor to sustain efficient combustion over a wide operating range. During a typical flight, the combustor will experience several transient events that, if not robustly managed by the flameholding system, could compromise engine performance and even vehicle life. For example, the flowfield that exists inside the combustor before ignition is significantly different than the flowfield after ignition. Also, as the engine accelerates from low to high flight velocity (e.g., Mach 4 to 8), the character of the flow within the combustor changes, the combustor fuel distribution may change, and the fuel itself may change (as a result of endothermic cracking). All of these changes may significantly impact the behavior and stability of the flameholder. Our research focuses on the understanding of flameholding in supersonic flows. We then strive to use that improved understanding to design and investigate more robust flame stabilization techniques for hydrocarbon-fueled scramjets. We have several experimental resources available to execute the research including two combustor thrust stands, a research combustor designed for a wide range of operation, and a stand-alone supersonic research facility specifically designed for non-intrusive probing of reacting and non-reacting flowfields to flameholding in a supersonic combustor. A wealth of conventional and advanced instrumentation is also available for measurements of pressure, temperature, velocity, and species concentration.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B5859: Gas Turbine Control Systems and Engine Health Management Research

Behbahani, A.

(937) 255-5637

The development of control systems and software that can deal with the dynamic and uncertain nature of highly integrated turbine engine systems depends on a fundamental understanding of the physics of propulsion. Robust, distributed, model based, and model predictive control concepts must be explored to achieve the desired capabilities in new gas turbine engine designs. While advances in control system technology will impact system performance at a given instance in time, a focus on tracking engine degradation is required to optimize performance over the life of the system. Research is required to develop a greater understanding of performance degradation mechanisms, and the impact of component degradation on system behavior.

The Air Force Research Laboratories Propulsion Directorate has established a Turbine Engine Dynamic Simulator (TEDS) as a real-time test bed for the development of advanced engine controls, diagnostics and prognostics. This simulator, data acquisition equipment and comprehensive engine models are used to explore simulation-based approaches for real-time, physics-based controls and health management algorithms. In a simulation based approach, a model of the propulsion system is embedded within the control system and tracks engine performance to continuously adjust to changes in the engine or operating environment. The use of a simulation based approach is also useful both in the context of virtual test where testing with actual systems is cost or time prohibitive and as embedded control system software to predicted sensed values where actual sensors could not be used.

As a result of this work, researchers gain a better understanding of the complex system interactions that exist in new propulsion systems and apply this knowledge in the development of future high performance, highly integrated systems.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B6706: Unsteady Aerodynamics and Heat Transfer in Turbines

Clark, J.

(937) 255-7152

An accurate accounting of unsteady flow phenomena is critical to the successful design of turbine components. This is especially true for future systems, where it is desirable both to increase engine performance and to reduce operating costs. Phenomena of current interest include vane-blade interactions, unsteady shock boundary-layer interaction, boundary-layer transition, separation control, and unsteady heat transfer and cooling as a result of the passage of turbine blade tips over outer air seals. Research opportunities in the turbine branch of the Turbine Engine Division typically have combined design, analysis, and experimental aspects. A complete design, analysis, and optimization system is in place to create advanced turbine components for validation testing in the laboratory. For example, by capitalizing on advances in transition modeling made at the laboratory, the system was used successfully to define exceptionally high lift low pressure turbine airfoils. High pressure turbine components with low heat load have also been defined and validated and we anticipate that further advances in the state-of-the-art in turbine aerothermodynamics are achievable with these design tools. Therefore, we are particularly interested in analytical work to improve the design system, including improvements in optimization techniques. In addition, a hybrid Reynolds-Averaged Navier Stokes/Large Eddy Simulation code is now being developed for incorporation into the system. It is also possible to access computational resources at the US Air Force Shared Resource Center to support projects. Experimental facilities available for design system validation and other research run the gamut from low-speed wind tunnels suitable for the assessment of fundamental flow physics on flat plates and cylinders in cross-flow, to low- and high-speed linear cascades (with and without heat transfer and/or cooling) and full scale, rotating transonic turbine rigs.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.01.B9931: System Integration Optimized for Energy Management

Yerkes, K.

(937) 255-6186

On demand systems require attention to issues of system integration and energy management for optimal performance and capability. Integrated system modeling and simulation spans a broad range of technical expertise such as thermal management, power generation, power distribution, and load management in a highly dynamic environment. Energy conversion is critical in the efficient design of on demand systems. For aircraft applications, the majority of energy conversion takes place in the gas turbine. Therefore, significant opportunities exist for optimizing this process, especially the consideration of auxiliary systems and how they interface with the hot gas engine sections. Gear boxes and starter/generators are key components of power generation leading to power distribution which is then connected to load management. Methods of storing and dissipating energy such as high-energy density batteries, super-capacitors, and heat exchangers are also vital for on demand system optimization which has regenerative energy capability. Underlying these system integration issues is the basic energy management issue of on demand highly dynamic thermal management. Depending on the on demand energy rates, fundamental assumptions such as thermodynamic equilibrium are violated. Therefore, research into various fundamental non-equilibrium thermodynamics methods such as mesoscopic thermodynamic descriptions of non-equilibrium thermodynamics, quantum thermodynamics, and extended irreversible thermodynamics is being accomplished. From an experimental view, hardware in the loop (HIL) system integration optimization for energy management will continue to be pursed. In particular, remote HIL system integration is vital to advancements in aircraft system integration. Finally, research into integrated system health management will continue to be utilized to optimize the complete system.

Keywords: System integration; Thermal management; Power handling; Energy conversion; Gas turbines; Non-equilibrium thermodynamics; Hardware in the loop (HIL); Health management; Heat exchangers

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.02.B0109: Physics of Electric Discharges

Adams, S.

(937) 255-6737

Basics atomic, molecular, and optical physics of electrically excited non-equilibrium gases are studied in a number of excited gas configurations including direct current, radio frequency, and microwave discharges, as well as laser excited gases. Research is primarily experimental and includes studies of ionization cross sections and ion-molecule reaction rates, excitation processes, energy transfer processes under non-equilibrium conditions, and gas breakdown mechanisms. Experimental facilities include a high resolution Fourier-transform mass spectrometer, modified for ionization cross section measurements, pulsed inductively coupled plasma source, laser excitation sources, plasma diagnostics including optical emission and absorption spectrometers, microwave interferometer and Langmuir probes. Applications include plasma processing and decontamination, control of plasma characteristics, and laser control of spark ignition.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.02.B0110: Applied Atomic and Molecular Spectroscopy

Scofield, J.

(937) 255-5949

Spectroscopic methods are developed and applied for quantitative measurements in nonequilibrium plasmas and high-temperature reacting flows. Well-defined low to medium pressure discharges using CW and pulsed direct current, low frequency to radio frequency, microwave excitations, and tandem pulsed-microwave excitations are investigated for their application to flow control in hypersonics, plasma enhanced etching, surface modifications, and dielectric breakdown. Experimental and theoretical studies are being conducted to characterize homogeneous and heterogenous processes in plasmas including plasma-surface interactions, plasma assisted ignition, and the creation and influence of self-ordered nanoparticles in plasmas. Power deposition scaling of atmospheric and near atmospheric pressure plasma properties including microplasmas are quantified by Stark spectroscopy, one- and two-photon allowed laser-induced fluorescence, Raman scattering, and photo absorption measurements using tunable visible to near-infrared, narrow line width diode laser sources. Experimental results are supported by theoretical modeling of electron kinetics and heavy particle interactions in nonequilibrium plasmas. A triple stage differentially pumped mass spectrometer is used to study transient discharge phenomena and photocatalytic reactions at medium to high pressure. We are also investigating the flux scaling properties of atmospheric pressure or near atmospheric pressure DBD plasma jet excited by short pulse duration, high reduced electric field dielectric barrier discharges for both vacuum ultraviolet/ultraviolet light source and low-cost surface coating applications.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.02.B4272: Research and Development of Efficient and Novel Thermal Management Approaches for Airborne Vehicles

Yerkes, K.

(937) 255-6186

Heat acquisition, transport, storage, and rejection represent fundamental limitations for future high-power, high-energy missions and for high-performance aerospace vehicles. Basic and applied heat-transfer and thermodynamic phenomena are examined analytically and experimentally with emphasis on their adaptation to airborne power-systems, electronic component thermal management, and directed energy weapon thermal management. Areas of interest include, but are not limited to single-phase, two-phase, multiphase systems, and high-performance rapid-responding thermodynamic systems; novel working fluid approaches for low and high temperatures (-55oC to >300oC for high-performance dielectric materials); nano and micro scale thermophysics; concurrent and countercurrent heat-transfer devices; capillary and other augmented heat-transfer methods for variable gravity applications; novel thermophysical and heat-transfer phenomena characterization; high- and low-temperature heat-transfer fluid-properties verification; unsteady heat transfer in pulsed and transient-phase change processes; analysis and verification of direct and indirect liquid cooling for electronic component temperature control; and the solution of the conjugate problem associated with this configuration for silicon carbide applications.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.02.B4833: Lithium-Ion Conducting Channel

Scanlon, L.

(937) 255-2832

Rechargeable lithium polymer batteries are of interest because of the very high-energy densities achievable relative to that of current generation batteries such as nickel-hydrogen. A key problem associated with the development of this battery has been the poor performance of the polymer electrolyte at ambient and subambient temperatures. Recent developments within our laboratory have demonstrated that a solid-state lithium ion conducting electrolyte (lithium ion conducting channel) can function over a broad temperature range from + 100 C to -50 C with very high specific conductivities on the order of 10 to 100 mS/cm. This electrolyte is particularly attractive since the transference number for lithium is one. The electrolyte was designed by computational chemistry with this feature as the anion matrix provides a constant negative electrostatic potential throughout the molecular system. This characteristic is important for operating over a broad temperature range since lithium ion transport no longer depends on polymer segmental motion but on the electric field gradient created by the potential difference of the electrodes within the electrochemical cell. Our goals are to simulate the electric field gradient using computational chemistry and applying it to the lithium ion conducting channel molecular system in order to correlate molecular structure with ionic conductivity. In addition, we intend to investigate the electrolyte/electrode interface through computational chemistry. We conduct research on ramjet/scramjet and mixed-cycle propulsion.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.02.B4834: Wide Temperature Range Power Semiconductors

Scofield, J.

(937) 255-5949

Research opportunities exist in the areas of power device design, development, and reliability assessment as they relate to wide bandgap power switch and diode performance in harsh environments. In addition to a consideration of carrier transport phenomena over wide temperature operational ranges, current research is focused on the thermo-mechanical aspects of device packaging to minimize CTE-related stresses and enhance reliability while providing the requisite electrical functionality. Novel composite and metallurgical materials are being investigated in module designs which aim to functionally optimize heat transfer efficiency and temperature distributions to minimize the stresses which drive conventional packaging failure modes. FEA modeling and simulation are extensively used to drive component designs which are subsequently validated empirically. In conjunction with this area of research is an interest in developing thermal models of heat transport across small-dimensional layers and interfaces that are not accurately described by Fourier conduction theory. A closely related area of research is in improving our understanding of the fundamental physics and chemistry of device failure in these emerging wide bandgap material systems. Efforts to determine activation energies and correlate device failure data with resident dislocations, inclusions, micropipe, and other defects is an area of high priority. Research interest also exists to develop sensors and optical interrogation techniques that are capable of providing accurate, repeatable, high-resolution response to small changes (<5%) in pressure, temperature, electrical current, voltage, and fluid flow under similar thermal environments.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.02.B4962: Superconductors, Thermoelectrics, Carbon Nanotubes, and Magnetic Materials for Advanced Power Applications

Haugan, T.

(937) 225-7163

The discovery of high-temperature superconductors (HTS), carbon nanotubes, thermoelectrics, and advanced magnetic materials offers many possibilities for their application in energy, power, and thermal applications and systems. However, a basic understanding of these materials, uniquely engineered structures, or the discovery of new materials (for superconductors, thermoelectrics, and magnetic materials) with their associated development is necessary to realize these applications. We are interested in both experimental and theoretical work, and modeling and simulation to accomplish these goals. Also the design and development of power devices is of interest to understand and demonstrate new capabilities. The following discusses each area as well as relevant general capabilities needed. In HTS, current emphasis is placed on the search for new superconductors at higher temperatures or more isotropic in current transport, and preferably operating above liquid hydrogen temperatures. Basic research is performed for the development of wire conductors, with emphasis on magnetic flux pinning enhancement, ac loss understanding and minimization, and stability and quench. Development of advanced superconducting wire is acceptable and can include conductor or cable configurations and coil windings. Thermoelectrics explore properties either at higher temperature for waste heat applications or as a means for cooling through the Peltier effect. Material emphasis is placed on multilayers and other nanostructures, oxides, and carbon nanotubes. Carbon nanotubes and composites are studied with an eventual goal to either achieve long lengths for electrical wiring/data transmission, or for thermal transport and structural support in a variety of electro-thermal environments including cryogenic. Magnetic materials research focuses on developing improved permanent magnets, such as high saturation and nanoparticle composite materials, and on soft magnetic material. Pulsed laser deposition, MOCVD, and MOD are the principal processes for thin-film growth in addition to the different materials for study of superconductors and thermoelectrics. Bulk growth of the magnetic materials and superconductors is of primary interest. CVD (both thermal and microwave) is typically used for growth of the carbon nanotubes.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.13.B0910: Advanced Catalysis for Hypersonic Vehicles

Reitz, T.

(937) 255-4275

Significant progress has been achieved to date in the development and demonstration of hypersonic engine technologies. These vehicle demonstrations currently utilize very basic power and thermal management subsystems whose only role is to provide limited operation for the short duration of the test flight. Advanced hypersonic vehicles, however, require sustained hotel power and cooling loads which may last several hours. Additionally, these vehicles operate in an extremely challenging environment making subsystem design a considerable challenge. Amongst the greatest of these subsystem challenges is long-duration (>10 min) thermal management of the vehicle, engine, and onboard electronics. Current research has focused on using the energy contained within the chemical bonds of the fuel to effectively store these aggressive heat loads prior to combustion. However, challenges associated with carbon fouling of the fuel lines due to non-selective fuel decomposition reactions currently limits operational life.

The objective of this effort is to explore advanced catalysis and reactor designs to promote selective endothermic fuel decomposition of relevant operational fuels. Interest areas include catalysis, kinetic, and reaction modeling studies of elevated temperature (200-700°C), high-pressure (20-60 bar) pyrolysis and partial-fuel reforming reactions.

Eligibility: Open to U.S. citizens

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.13.B0911: Formal Methods for Design and Verification of Autonomous Systems

Humphrey, L.

(937) 255-6326

The USAF has called for a dramatic increase in the use of highly autonomous systems. However, a lack of suitable verification and validation methods prevents all but the simplest autonomous systems from being deployed. Furthermore, the increasing complexity of modern systems is exponentially driving up the costs of traditional testing, verification, and validation methods. To address these issues, innovations and improvements are needed throughout the systems engineering process.

Toward this end, we are investigating the use of formal methods. Formal methods can be roughly defined as mathematically based tools and techniques for specifying, designing, and verifying systems. Currently, there are two major classes of formal methods: automated theorem proving and model checking. These methods have to potential to 1) make the system requirements and design phases more rigorous, reducing errors early in the systems engineering process, 2) provide a better foundation for the design of complex systems, 3) automate portions of the verification process, and 4) provide better tools for tracing and tracking errors.

Examples of research in this area include:

* Writing formal, mathematical system requirements and checking that they are consistent and complete.

* Designing or synthesizing decision-making protocols for multi-agent systems and verifying that they result in correct system operation over a variety of environmental and/or adversarial conditions.

* Designing interfaces for a modular and flexible systems-of-systems, so that modules only need to be verified against interface specifications, and interface specifications can be used to verify the system as a whole.

* Creating human-automation systems and interfaces for UAV mission planning and execution that follow the model checking paradigm, where mission plans are analogous to system specifications, mission executions are analogous to system models, and counterexamples can be used to highlight problems in the mission.

*Eligibility: Citizenship: Open to U.S. citizens and permanent residents.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.13.B0912: Multidisciplinary Aircraft System Design Utilizing Topology Optimization

Joo, J.

(937) 713-7137

Future aircraft still are designed for mission performance, survivability, sustainment, and many other required constraints. The needs of reconfigurable systems, adjustable to multiple flight environments such as morphing aircraft, is desired for future aircraft systems to meet economical and mission performance. Despite the recent advances in computational design technology, multifunctional and multidisciplinary design requirements make the design difficult due to the large design space. Designers’ experience and input are important to make critical design decisions during the process, but the translation of their experience into mathematical terms is not well established. In order to cope with the multi-physics design environment, research opportunities exist in the general idea of topological design optimization for aircraft system design.

Areas of interests include: (1) Aircraft subsystem packaging design using topology optimization considering access for maintenance, static stability, static margin, structures around subsystems, etc; (2) Multidisciplinary topology and shape optimization considering aerodynamics, aeroelesticity, and aerothermodynamics; (3) Aircraft planform and structure design using topology optimization to improve vehicle fuel efficiency and aerodynamic performance; (4) Reconfigurable aircraft system design using state of the art design methodologies such as compliant mechanism design and/or origami engineering.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.13.B0913: Cooperative Control of Autonomous Systems in Uncertain Information Environments

Casbeer, D.

(937) 255-4895

This research focuses on cooperative control problems involving autonomous agents in uncertain environments with communication restrictions. Typical scenarios of interest involve different modalities of communication, e.g., high-bandwidth, high-rate communications for short range peer-to-peer interactions and low-bandwidth, low-rate communications over larger distances. Agents must be able to intelligently adapt to the situation at hand and base decisions on the locally available (and uncertain) information, while still guaranteeing success of the overall mission. To accomplish this, the agents must be able to ascertain what information is important to ensure correct and appropriate decision-making for success of the overall mission objective. Furthermore, with the necessary information for mission success determined, the agents must be able to keep this information accurate and up-to-date given the changing (possibly distributed) communications restrictions. With such systems, analytical tools are needed to guarantee overall mission success given that decision-making is distributed with uncertainty. The overarching topics of interest for this research effort can be summarized as follows: value-of-information, distributed estimation, and distributed decision-making/control.

*References:

K. Krishnamoorthy, M. Pachter, S. Darbha, P. Chandler, Optimization of Perimeter Patrol Operations using UAVs, AIAA J. Guidance, Control and Dynamics, 2011.

K. Krishnamoorthy, D. Casbeer, P. Chandler, M. Pachter and S. Darbha, UAV Search & Capture of a Moving Ground Target under Delayed Information, IEEE Conf. Decision and Control, 2012 (to appear).

D. Casbeer, K. Krishnamoorthy, A. Eggert, P. Chandler and M. Pachter, Optimal Search for a Random Moving Intruder, Proc. AIAA Infotech@Aerospace Conf. 2012.

*Keywords:

distributed and robust decision-making, (partially-observable) Markov decision process, intelligent control, distributed estimation, sensor fusion, value-of-information, multi-agent

*Eligibility:

Citizenship: Open to U.S. citizens and permanent residents.

AFRL/RQ WRIGHT PATTERSON AF BASE, OH

SF.30.13.B1109: Two Phase Heat Transfer

Byrd, L.

(937) 255-3238

Next generation aircraft have a significant increase in thermal loads due to a transition to more electric aircraft, more powerful electronics, and the use of more composite structures. Two phase heat transfer is being used to provide thermal management for these aircraft. This can provide energy transfer that is orders of magnitude more efficient than single phase cooling thus allowing increased heat fluxes with almost isothermal surfaces at 1% of the mass flow rate. Vapor compression cooling systems utilizing two phase heat transfer are seen as essential components for the INVENT program to reach its goals.

Toward this end, we are investigating the limitations of two phase heat transfer. This includes the critical heat flux and heat transfer coefficient for a number of configurations including pool boiling, thin film evaporation, spray cooling, and jet impingement. Pressure drop and stability are also of concern for situations where there is two phase flow and in systems with multiple evaporators or condensers.

Examples of research in this area include:

*Increasing heat transfer and critical heat flux through the use of surface enhancements such as porous coatings or nanoscale features that promote early bubble release and good rewetting.

*Nonlinear control and stability of two phase systems with transient loads and multiple heat exchangers. This includes system level as well as component level response.

*Energy optimization control schemes for two phase thermal management systems that can be integrated into a platform level energy optimization manager.

*Two phase systems that use working fluids that can reject heat at higher temperatures than current refrigerants.

*Eligibility: Citizenship: Open to U.S. citizens and permanent residents.

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.03.B6678: Computational Studies of Energetic Materials for Rocket Propulsion ApplicationsComputational Studies of Energetic Materials for Rocket Propulsion Applications

Boatz, J.

(661) 275-5364

This research focuses on the application of high-level quantum chemical computations to the study of advanced energetic compounds for space and missile propulsion applications. These calculations are used to predict the thermodynamic and kinetic stability, performance, spectroscopy, potential synthesis routes, reaction pathways, and other properties of candidate molecules. These results aid in the initial screening of new energetic compounds for subsequent experimental synthesis, characterization, and scaleup. Specific classes of compounds of interest include energetic ionic liquids, polynitrogen/high-nitrogen compounds, nanoclusters, and energetic solid ingredients. Because of the large size and complexity of many of the compounds of interest, utilization of high-performance computing methods and resources is an essential component of this research effort. A critically important resource for these studies is state-of-the-art high-performance computing systems made available to DOD researchers through the High Performance Computing Modernization Program.

Keywords: Energetic materials; Quantum chemistry; Computational molecular chemistry; High-performance computing

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.03.B6921: Advanced Polymer Composites for Propulsion Applications

Mabry, J.

(661) 275-5857

The development of polymer nanocomposites and fiber-reinforced polymer matrix composites has resulted in significant improvement in thermal, mechanical, and physical properties in many aerospace applications. The property improvements enabled by these materials have resulted in their use in many defense-related applications. In addition to property improvement, production of functional composites at reduced cost is also desired. AFRL/RQ is recognized as a leader in the field of composite materials research. An opportunity exists for research in the area of polymer nanocomposites and fiber-reinforced polymer matrix composites. The Rocket Propulsion Division, Propellants Branch conducts both basic and applied research, leading to the development of advanced materials for use in various applications. Chemical aspects of the research involve the synthesis and characterization of monomers, polymers, resins, and composites. Research is performed by both scientists and engineers, working together as an interdisciplinary team. US citizenship is required for this position. Please state prominently in any correspondence that you are a US citizen.

References:

Mabry J, et al: Angewandte Chemie International Edition 47: 4137, 2008

Chhatre SS, Mabry JM, et al: ACS Applied Materials & Interfaces 2: 3544, 2010

Moore BM, Mabry JM, et al: Journal of Organometallic Chemistry 696: 2676, 2011

Guenthner AJ, Mabry, JM, et al: Macromolecules 454: 211, 2012

Keywords:

Polymer; Resin; Composite; Nanocomposite

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.03.B7524: Multifunctional Composite Structures for Space and Missile Propulsion and Power

Guenthner, A.

(661) 275-8020

Higher efficiency propulsive systems represent a key need for future space and missile platforms in both civilian and military applications. In particular, the development of lighter weight structures using advanced materials has long been recognized as an important enabling technology for achieving higher efficiency. An unconventional approach to achieving weight reduction is through the use of structures that perform multiple functions, such as load bearing, protection from harsh operational environments, and energy storage, saving both space and weight. In energy conversion devices such as propulsion systems, the co-located availability of multiple forms of energy creates an especially attractive opportunity to exploit multifunctional structures. Embedded sparse networks provide a means of dedicating a portion of a structure to a second function while minimizing the negative impact on mechanical properties, whereas embedded electroactive organic materials and nanoparticle reinforcements in composite matrices provide a mechanically robust venue for combining sensing, energy storage, and structural reinforcement in a single component.

References

Guenthner AJ; Hess DM; Cash JJ: Journal of Polymer Science, Part B: Polymer Physics 48: 396, 2010

Stenger-Smith JD, Guenthner AJ, et al: Journal of the Electrochemical Society 157: A298, 2010

Keywords: Polymers; Propulsion; Multifunctional; Energy storage; Electroactive; Lightweight;

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.04.B0202: High Pressure and Supercritical Combustion

Talley, D.

(661) 275-6174

The objective of this work is to investigate atomization and combustion of liquid propellants at high pressures including supercritical pressures. Current understanding of spray combustion processes is based mostly on low pressure, subcritical mechanisms, whereas future Air Force propulsion and other combustion applications will increasingly emphasize high pressures. Atomization and spray combustion mechanisms may be different in these regimes. At pressures exceeding the critical point of the propellant (731 psi for liquid oxygen), the sharp distinction between gas and liquid phases can entirely disappear, and we can question whether droplets can even exist. Such flows will likely exhibit properties, which at some times are like those of turbulent jets and at other times are more like those of sprays. Even subcritical high pressures pose substantial challenges for combustion diagnostic techniques, most of which were developed for low-pressure applications. To be overcome are obstacles such as dense sprays, beam steering, molecular quenching, and spectral line broadening. Numerous research opportunities are available to work with an established team of scientists and engineers to improve technology in this area.

Keywords: Liquid propellants; Supercritical fluids; Drops (liquids)

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.04.B0203: Plasma Physics of Electric Propulsion Devices

Hargus, W.

(661) 275-6799

The objective of this research is to investigate the operating physics of existing electric propulsion devices to improve thruster performance, as well as to develop new schemes for highly efficient plasma acceleration for spacecraft propulsion applications. Important study areas include plasma physics, pulsed power system design and coupling, internal energy distributions, and heat transfer. Research efforts include experimental time resolved diagnostics and numerical modeling of these plasmas. We are particularly interested in developing pulsed inductive accelerators to exploit increasingly higher spacecraft onboard power, to provide high thrust density, low mass, highly throttlable propulsion for emerging DoD missions. Diagnostics efforts focus on the development of time resolved measurement capabilities to enable characterization of microsecond timescale plasma formation and provide high fidelity data for code validation. Numerical simulation of the plasma formation and interaction between thruster components and various plasma probes (e.g., retarding potential probes, Wein filters) is also an area of interest.

Keywords:

Plasma physics; Electric propulsion; Plasma simulation

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.04.B3754: Basic Research in Electric and Spacecraft Propulsion

Hargus, W.

(661) 275-6799

Air Force research on plasmas formed by electric spacecraft thrusters explores the mechanisms of plasma formation and acceleration. This research is valuable in both assessing the suitability of various electric propulsion concepts as well as developing simulation tools to predict thruster lifetime and plume effects on the host spacecraft. Of particular interest is improving the understanding of the turbulent plasma mechanisms that govern electron transport within partially magnetized plasmas. Cross-field electron transport in these plasmas governs the thruster physics and limits maximum achievable efficiencies. In concert with new numerical simulation techniques, advanced non-intrusive diagnostics are being used to measure the internal plasma properties of these thrusters in order to further develop our understanding of the inherent plasma turbulence. Previous measurements have been limited to measurements of time averaged plasma properties; however, to fully characterize the plasma turbulent transport, new time resolved plasma diagnostics are being developed. These diagnostic and simulation efforts are supporting the development of tools to characterize thruster plasma-spacecraft interactions and the accurate prediction of thruster lifetime in support of Air Force flight programs.

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.04.B5781: Experimental Methods for Solid Propellant Mechanical Behavior Characterization

Miller, T.

(661) 275-5323

Solid propellants are a unique class of materials that behave in a viscoelastic manner but also develop damage as an effect of aging. Methods for characterizing propellant mechanical properties have been adapted from linear elastic, small strain experimental methods, but these approaches are lacking in fidelity. We are interested in developing advanced experimental methods of determining the mechanical behavior parameters of propellants in various stress states so that the results can be used to predict the mechanical response of the propellant grain. Properties such as Prony series, Williams-Landel-Ferry (WLF) parameters, fracture parameters (J-integral and fracture toughness KIC), and damage parameters are considered important. Although the time and temperature dependent nature of these parameters is important, other environmental factors may also be investigated (for example, pressure, or humidity). Using techniques such as Digital Image Correlation or Dynamic Mechanical Analysis, we would like to develop algorithms that successfully improve the characterization of these properties and that give additional insight into the nature of solid propellant mechanical behavior under conditions experienced by solid rocket motors.

Keywords: solid rocket propellant, digital image correlation, dynamic mechanical analysis, Prony series, WLF parameters, fracture mechanics, damage mechanics

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.04.B6683 : Characterization of Hall Thruster Lifetime

Hargus, W.

(661) 275-6799

The prediction of Hall thruster lifetime is a research topic encompassing both plasma measurement and simulation. Current thruster internal plasma simulations do not predict critical plasma properties with sufficient fidelity to accurately extend these simulations to the prediction of thruster lifetime. In addition, critical sputtering parameters are not adequately characterized for the dielectric walls of Hall thruster acceleration channels. This research is a multidisciplinary effort to improve the physics simulated in the thruster plasma models, experimentally verify these models using advanced plasma diagnostics, and determine the critical plasma/material interaction parameters such as sputter yield, onset energy for sputtering, and secondary electron yield for Hall thruster plasma wet materials.

Diagnostic efforts consist of the application and development of minimally intrusive diagnostics to characterize both the Hall thruster internal plasma and the sputter erosion of various dielectrics. Plasma modeling efforts focus on the incorporation of additional physics into currently available models. A major focus for both plasma diagnostics and simulation is the development of improved understanding of the electron transport within the Hall thruster. This improved understanding requires characterization and models of the plasma turbulence and shear that govern electron transport.

Characterizing the plasma interactions with Hall thruster internal surfaces is vital to predicting lifetime. Research interests include the characterization of dielectric sputtering, both experimentally and numerically. Other topics of interest include the characterization of electron secondary emission due to electron bombardment and low energy ion interactions with surfaces leading to the onset of sputtering.

Keywords: Electric propulsion; Hall thruster; Sputtering; Plasma physics; Plasma simulation; Plasma diagnostics

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.05.B0204: Materials Science of High Temperature Materials

Hoffman, W.

(661) 275-5768

Although carbon-carbon composites are excellent high-temperature structural materials and are employed extensively in many operating systems, research is needed to extend their use into different applications and environments, as well as to greatly reduce their cost. Our composites research focuses on low-cost rapid densification techniques for carbon fiber preforms, the use of nanophase materials in novel oxidation protection systems, as well as methods to enhance the interlaminar properties of these composites. Research is also being performed in the areas of nano-reinforcement of carbon fibers, control of wettability utilizing surface geometry, supercritical fluid deposition of refractory materials, and microtube technology. These microtubes can be made in various cross-sectional and axial shapes from practically any material. To date, microtubes with an ID as small at 0.1 microns have been fabricated, although the lower limit is thought to be 5 nm. Microtubes may be made free-standing or may form tubes or channels in monolithic bodies.

Keywords: Carbon-carbon composites; High-temperature composites; Fiber composites; Microtubes; Microdevices

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.05.B7618: Computational Physics of Nonequilibrium Plasma for Space Propulsion

Cambier, J-L.

(661) 275-5649

This research topic in applied physics and mathematics focuses on the development and application of advanced numerical methods and physical models applied to plasma dynamics for conditions relevant to various applications of interest to the Air Force, particularly electric propulsion systems. Physical regimes range from rarefied plasma to ideal MHD, weakly to fully ionized, and with temperatures up to 100 eV. We are particularly interested in multiscale methods, hybrid methods, and innovative mathematical and numerical approaches to solving plasma kinetics. Fluid (MHD) and multi-fluid models, collisional-radiative (CR) kinetics, particle-in-cell (PIC), and Monte-Carlo collisions (MCC) methods are of typical interests, as well as Vlasov/Fokker-Planck approaches and their combination.

References: Kapper MG, Cambier JL: Journal of Applied Physics 109: 113308, 2011

Kapper MG, Cambier JL: Journal of Applied Physics 109: 113309, 2011

Keywords: Plasma; Nonequilibrium; Collisional-radiative; MHD; PIC; Vlasov

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.06.B6891: Synthesis of Novel Polymer Composite Monomers and Resins

Mabry, J.

(661) 275-5857

The chemical synthesis of novel molecules and reactive monomers, as well as their use in thermoplastic and thermosetting polymer nanocomposites, has resulted in significant improvements in a wide variety of polymer composite systems. Property improvements enabled by these materials have resulted in their use in several rocket propulsion and other defense-related applications. In addition to property improvement, synthesis of functional molecules and compounds at reduced cost is also desired. AFRL/RQ is a leader in the field of reinforced polymer composite research. An opportunity exists in the Air Force Research Laboratory at Edwards AFB for research in the synthesis of novel molecules, compounds, and polymer composites. A qualified candidate will have experience in organic, inorganic, organometallic, or polymer synthesis, or a combination of these areas. The Rocket Propulsion Division, Propellants Branch conducts both basic and applied research, leading to the development of advanced materials for use in rocket propulsion and other defense applications. Chemical aspects of the research involve the synthesis and characterization of new materials and polymer composites. These materials can be utilized for the modification of polymer properties, such as resistance to wetting by water and hydrocarbons, oxidation-resistance, thermal stability, and ease of processing. Aspects of this work involve the design and synthesis of monomers and polymers, as well as functional nanomaterials with novel architectures and composite resin development. Research is performed by both scientists and engineers, working together as an interdisciplinary team. US citizenship is required for this position. Please state prominently in any correspondence that you are a US citizen.

References:

Tuteja A, Choi W, et al: Science 318: 1618, 2007

Mabry JM, et al: Angewandte Chemie, International Edition 47: 4137, 2008

Mabry JM, et al: Langmuir 27, 10206, 2011

Mabry JM, et al: Journal of the American Chemical Society 133, 20084, 2011

Keywords: Synthesis; Polymer; Oleophobic; Nanocomposite; Nanomaterial; Composite; Hydrophobic

Eligibility: Open to U.S. citizens

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.13.B1110: Computational Algorithm Development for Rocket Propulsion Flowfield Simulations

Sankaran, V.

(661) 275-5534

Rocket propulsion flowfields offer significant challenges to computational modeling because of the complex turbulent reacting multiphase physics, the presence multiple length and time scales, and the unsteady nature of the flow phenomena. This topic concerns the investigation of numerical algorithmic aspects to address these challenges from the viewpoint of ensuring solution accuracy, robustness, efficiency and scalability. Specific areas of interest include improved flux schemes that can preserve uniform accuracy at all Mach, Reynolds, and Strouhal numbers; high-order accurate spatial and temporal discretizations; enhanced implicit solution techniques; and automated time-step control for the robust solution of stiff and highly nonlinear problems. The technical approach will involve the use of numerical analysis tools such as von Neumann stability, asymptotic theory, and the method of manufactured solutions as well the development and implementation of the algorithms in candidate computational fluid dynamics codes. Particular emphases will be placed on unsteady flow simulations with DES or LES models for turbulence, generalized equations-of-state for high-pressure super-critical problems, finite-rate chemical kinetics, and stochastic-PDF methods for turbulent combustion. Verification and validation will be targeted towards canonical spray and combustion problems, as well as practical rocket flowfield simulations involving solid motors, liquid rocket engines, cryogenic turbomachinery, and/or electric thrusters.

Keywords:

Computational fluid dynamics; Algorithm development; Propulsion flowfields; Liquid rocket engines; Solid rocket motors; Cryogenic turbomachinery;

*Eligibility: Citizenship: Open to U.S. citizens.

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.13.B1111: Novel Meshing Paradigms for Rocket Propulsion Flowfield Simulations

Sankaran, V.

(661) 275-5534

This research focuses on the exploration of novel meshing paradigms for computational fluid dynamics simulations of internal rocket flowfields. Current meshing paradigms have both strengths and weaknesses. Cartesian meshes are efficient and accurate, but are not suitable for capturing near-wall boundary layer phenomena; curvilinear structured meshes are efficient, accurate, and suitable for boundary layers, but the grid generation is complex and tedious; unstructured meshes are much easier to generate and are well-suited to boundary layers, but they are relatively inefficient and are typically restricted to second-order accuracy at best. The technical approach is to combine different mesh types within a single flowfield simulation so that the domain is effectively mapped by the grid-types best suited to the local requirements. Thus, the off-body region can be represented by Cartesian meshes, while the near-body region is governed by body-fitted structured or unstructured meshes. Connectivity between the different mesh systems is usually accomplished using overset grid technology. We anticipate that the judicious combination of such mesh types can lead to over two orders of magnitude savings in computational time and provide significant enhancements of solution accuracy. The specific topic of interest is the development of such a multiple-mesh infrastructure for internal flowfields that are representative of rocket propulsion flowfields. Additional areas of interest include (1) automated adaptive mesh refinement technology, (2) effective domain decomposition and load balancing algorithms, and (3) improved overset interpolation and/or conservative flex-exchange methods for inter-mesh information transfer. Research and development will be conducted within an existing code infrastructure and the methods applied to rocket propulsion flowfields including solid motors, liquid engines, cryogenic turbomachinery and/or electric thrusters.

Keywords:

Computational fluid dynamics; Overset grids; Internal rocket flowfields; Adaptive mesh refinement;

*Eligibility: Citizenship: Open to U.S. citizens.

AFRL/RQ EDWARDS AF BASE, CALIFORNIA

SF.30.13.B1112: Combustion and Ignition Chemistry of Energetic Propellants

Vaghjiani, G

(661) 275-5657

Our research centers on fundamental chemical kinetics and applications in combustion chemistry of energetic propellants. The rates of elementary reactions are measured using various direct time-resolved techniques such as pulsed laser photolysis, coupled with laser-spectrometric or mass-spectrometric probing of the short-lived species in the gas phase. We also use rapid-scan FTIR absorption spectroscopy to probe the formation of stable products in these reactions. Heterogeneous processes, such as the reactions of aerosolized propellant fuel in various oxidizing gaseous environments, are studied using the VUV-PI-TOFMS experimental set-up of the Chemical Dynamics Beamline 9.0.2.3 at the Advanced Light Source Synchrotron Facility at the Lawrence Berkeley National Laboratory in Berkeley, CA. Direct molecular dynamics simulations are also performed to identify pertinent chemical processes in the combustion of propellant mixtures. Chemical models of these processes are constructed using ab initio quantum chemical, TST and RRKM theories to understand the mechanisms. The laboratory data is extrapolated to operational conditions in the prediction of ignition delay times, a quantity of significant importance in the design of rocket engines.

References:

Liu J, Chambreau SD, Vaghjiani GL: Journal of Physical Chemistry A115: 8064, 2011

Chambreau SD, et al: Journal of Physical Chemistry Letters 2: 874, 2011

Keywords:

Combustion chemistry; Propellant ignition; Reactions kinetics; Time resolved laser spectroscopy; FTIR spectroscopy; TOF mass spectrometry; Chemical mechanisms; Quantum chemical calculations; Molecular dynamics simulations;

*Eligibility: Citizenship: Open to U.S. citizens.

USAFSAM 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0848: Validation of Clinical Vision Tests Utilizing Operational Based Vision Assessment (OBVA)

Gooch, J.

(937) 938-2637

Selected OBVA projects will establish operationally-based visual performance measurements utilizing high fidelity flight simulation. OBVA will assess the operational relevance of current visual standards, and develop and validate new metrics of visual performance for present-day pilots, RPA operators, and other aircrew. The relationship between clinical tests and operational performance is complex, dynamic, and multidimensional. Current AF vision standards generally date to the WWI/WWII era and require updating. Technology has changed dramatically since then, and so should our standards and vision screening procedures. OBVA research projects will focus on tasks and operational conditions in which vision becomes a limiting condition. Areas of focus include: (1) assessment of visual acuity with airborne/ground-based target detection, identification and tracking operational tasks, (2) color vision assessment utilizing operational tasks such as viewing and interpreting HUD/HMD/HDD displays and external lighting (e.g. PAPI lights), (3) stereopsis testing/correlation with operational tasks such as aerial refueling, hover/ground clearance, and NVG scanning, and (4) contrast sensitivity assessment utilizing various simulated operational conditions, such as flight operations under degraded visual conditions.

Candidates with demonstrated experience in any of the following: psychophysics, theoretical and computational neuroscience, color vision, motion perception, eye-tracking, binocular vision and stereoacuity, spatial vision, sensory integration and biological information fusion, , perception and action, and retinal/cortical disorders are desired. Selected applicants should expect to work with USAFSAM military and civil service staff, federal contractors, and collaborating university faculty.

Key Words: Operational Based Vision Assessment (OBVA), Visual Acuity, Color Vision, Stereopsis, Contrast Sensitivity, motion perception

References:

Ball, K., & Owsley, C. (1992). The useful field of view test: A new technique for evaluating age-related declines in visual function. Journal of the American Optometric Association, 63, 71–79.

Barbur, J., Radriguez-Carmona, M., Evans, S., & Milburn, N. (2009). Minimum Colour Vision requirements for professional flight crew: Recommendations for new colour vision standards (CAA Paper 2009/04). Civil Aviation Authority.

Cole, B. and Maddocks, J. (2008). Color vision testing by Farnsworth Lantern and ability to identify approach-path signal colors. Aviation, Space, and Environmental Medicine, 79 (6), pp. 585 – 590.

Diepgen R. Do Pilots Need Stereopsis? Klin Monbl Augenheilkd (1993); 202(2): 94-101.

Entzinger J. (2009). The Role of Binocular Cues in Human Pilot Landing Control. Proceedings of Thirteenth Australian Aerospace Conference.

Gaska, J., Gooch, J., and Winterbottom, M. (2011). OBVA Operational Scenario Development. Presentation at Advanced Technology Applications for Combat Casualty Care (ATACCC)

Gaska, J., Winterbottom, M., Sweet, W., and Rader, J. (2010). Pixel Size Requirements for Eye-Limited Flight Simulation. Proceedings of the IMAGE 2010 Conference, The IMAGE Society, pp. 123-130.

Gaska, J., Clark, P., Winterbottom, M., Sweet, B., and Gooch, J. (2009). Operationally Based Vision Assessment Laboratory Development. Aerospace Medical Association Annual Meeting.

Ginsburg A, Easterly J (1983) Contrast sensitivity predicts target detection field performance of pilots. Proceedings of the Human Factors Society. pp 269–273.

Ginsburg AP, Evans DW, Sekuler R, Harp SA (1982) Contrast sensitivity predicts pilots’ performance in aircraft simulators. Am J of Optometry and Physiological Optics 59: 105–109.

Gooch, J. (2012). Stereopsis standards for U.S. Air Force boom operators. Aerospace Medical Association Annual Meeting Presentation.

Hong, X. & Regan, D. M. (1989). Visual field defects for unidirectional and oscillatory motion in depth. Vision Research, 29, 809-819.

Hovis, J. (2012). Comparison of three computer based color vision tests. Presentation at the 82nd Aerospace Medical Association Annual Meeting, Anchorage, AK.

Ishigaki, H. & Miyao, M. (1993). Differences in Dynamic Visual-Acuity between Athletes And Nonathletes. Perceptual and Motor Skills, 77, 835-839.

Kruk, R, & Regan, D. (1983). Visual test results compared with flying performance in Telemetry tracked aircraft. Aviation, Space and Environmental Medicine 54, 906–911.

Kruk, R., Regan, D., Beverley, K.I., & Longridge, T. (1983). Flying performance on the Advanced Simulator for Pilot Training and laboratory tests of vision. Human Factors, 25, 457–66.

Lloyd, C.J. and Nigus, S. (2012). Effects of stereopsis, collimation, and head tracking on air refueling boom operator performance, Proceedings of the IMAGE Conference, Scottsdale, AZ.

Lloyd, C.J. (2012). On the utility of stereoscopic displays for simulation training. Proceedings of the Interservice/Industry Training, Simulation, & Education Conference. Orlando FL.

Monlux, D., Finne, H., and Stephens, M. (2010). Color blindness and military fitness for duty: A new look at old standards. Military Medicine, 175, pp. 84 – 86.

Rabin, J., Gooch, J., and Ivan, D. (2011). Rapid quantification of color vision: the cone contrast test. Investigative Ophthalmology and Visual Science, 52 (2), pp. 816 – 820.

Watson, A., Ramirez, C., and Salud, E. (2009). Measuring and predicting visibility of aircraft. PLoS ONE, 4 (5).

Winterbottom, M., Gooch, J., Wright, S., Gaska, J., Gao, H., Lloyd, C., and Hadley, S. (2012). Operational Based Vision Assessment (OBVA) Research Involving Depth Perception. Presentation at the International Congress on Aerospace Medicine, Melbourne, Australia.

Wood, J. and Owens, A. (2005). Standard Measures of Visual Acuity Do Not Predict Drivers’ Recognition Performance Under Day or Night Conditions. Optometry and Vision Science, 82 (8), pp. 698–705.

USAFSAM 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0849: Number: Visual Simulation Technology: Operational Based Vision Assessment (OBVA)

Gooch, J.

(937) 938-2637

The OBVA Laboratory will utilize high fidelity flight simulation to assess the operational relevance of current vision standards, and develop and validate new metrics of visual performance for present-day pilots, UAV operators, and other aircrew. Currently, AF vision standards are based primarily on clinical tests. OBVA research projects will assess visual acuity, color vision, stereopsis, and contrast sensitivity and correlate them with operational tasks commonly performed by pilots and other aircrew such as: airborne/ground-based target detection, identification and tracking targets, viewing and interpreting HUD/HMD/HDD displays, aerial refueling, hover/ground clearance, and NVG scanning. Operational conditions, such as helicopter whiteout/brownout, haze, and fog, will also be simulated to assess visual performance. This research will be used to improve safety, visual performance and to aid in selection/retention of aircrew.

Candidates with demonstrated experience in C++ programming, scene graph development using Open GL and Microsoft Visual Studio are strongly desired. Candidates will be expected to work with software and hardware designers to extend the capabilities of a custom simulation system; participate in teams that conceive, plan and conduct research on the Operational Based Vision Assessment Laboratory (OBVA); and use simulation technology to quantify the relationship between laboratory or clinical measures of visual capabilities and performance in flight-related operational tasks. Selected applicants should expect to work with USAFSAM military and civil service staff, federal contractors, and collaborating university faculty.

Key Words: Operationally Based Vision Assessment (OBVA), Computer Science, Simulation Technology

References:

Archdeacon, J., Gaska, J., and Timoner, S. (2012). An Operationally Based Vision Assessment Simulator for Domes. Proceedings of the IMAGE 2012 Conference, The IMAGE Society.

Entzinger J. (2009). The Role of Binocular Cues in Human Pilot Landing Control. Proceedings of Thirteenth Australian Aerospace Conference.

Gaska, J., Winterbottom, M., Sweet, W., and Rader, J. (2010). Pixel Size Requirements for Eye-Limited Flight Simulation. Proceedings of the IMAGE 2010 Conference, The IMAGE Society, pp. 123-130.

Ginsburg AP, Easterly J. Contrast sensitivity predicts target detection field performance of pilots. Proceedings of the Human Factors Society. 1983: 269-273.

Ginsburg AP. Direct performance assessment of HUD display systems using contrast sensitivity. IEEE NAECON Mini course Notes, Dayton, Ohio, May 17-19, 1983, pp. 33-44.

Gooch, J. (2012). Stereopsis standards for U.S. Air Force boom operators. Aerospace Medical Association Annual Meeting Presentation.

Lloyd, C.J. and Nigus, S. (2012). Effects of stereopsis, collimation, and head tracking on air refueling boom operator performance, Proceedings of the IMAGE Conference, Scottsdale, AZ.

Lloyd, C.J. (2012). On the utility of stereoscopic displays for simulation training. Proceedings of the Interservice/Industry Training, Simulation, & Education Conference. Orlando FL.

USAFSAM 711TH HPW WRIGHT-PATT AFB, OH

SF.15.14.B0850: Assessment of Aeromedical Evacuation Transport Patient Outcomes with and without Cabin Altitude Restriction

Dukes, S.

(937) 938-3101

Aeromedical evacuation (AE) uses aircraft to transport regulated injured or ill patients while providing medical care en route. In-flight medical care carries with it a number of stressors, such as gravitational forces, low humidity, reduced oxygen, increased vibrations, reduced temperature, gas expansion, turbulence, noise, and crowded spaces. Most notably, cabin altitude can have adverse effects (such as hypoxia and interstitial fluid shifting) on patients being transported, particularly among patients with pulmonary disease, blood transfusion patients, or any patient at risk for gas expansion. Cabin altitude restriction (CAR) is commonly used to protect these vulnerable patients in flight by restricting the altitude to which the cabin is permitted to rise. This increases the potential for turbulence, fuel consumption, flight time, and potential for refueling (Butler et al., 2012), using valuable resources and increasing the time that the patients are exposed to in-flight stressors.

This study is to investigate the differences in clinical outcomes between patients who undergo AE transport with and without CAR. The most common missions flown with CAR are those from in-theater to Ramstein, Germany but are also ordered for intratheater missions. Therefore, this study will target both the intra and intertheater AE missions arriving at Ramstein.

This study intends to investigate outcomes until the patient departs Germany or 7 days post flight, whichever is shorter to ensure a thorough study of the outcomes, as previous studies typically only investigated a 24- to 72-hour time period.

A data collection tool will be used to extract key data elements from TRAC2ES, TMDS, AHLTA, and DoDTR. We will attempt to select controls who have the same or similar conditions as those who were transported with CAR. We plan to investigate the entire population of AE patients for whom a CAR was ordered from 2007 through 2012.

Key Words: Aeromedical Evacuation, Cabin Altitude Restriction

References:

Butler WP, Steinkraus LW, Popey TL, Burlingame EE. Aggressive Validating Flight Surgeon (VFS) Aeromedical Evacuation Management Associated with a Reduction in the Incidence of Post-Flight Major Complications. Aerospace Medical Association, 82nd Annual Scientific Meeting. 2012.

Air Force Test Center

SF.60.14.B1003: Fundamental Research in Test Science, Test Engineering, and the Analysis of Test Results

Belk, D.

(661) 277-4436

We have many opportunities to work with senior scientists and engineers at locations throughout the country. Specific areas of interest are described by advisors working at our ranges and test facilities (Edwards AFB 412 TW, Eglin AFB 96 TW, and Arnold AFB AEDC), but placement with other advisors or other locations is possible. These include test sites at Wright-Patterson and Holloman AFB. We are interested in research topics that advance and improve test science, test engineering, and our ability to properly interpret test results. Basic research in areas that advance the science of test is broadly defined and spans mathematics as well as most disciplines in engineering and the physical sciences. These include:

• Novel measurement techniques, materials, and instruments that enable accurate, rapid, and reliable test data collection of physical, chemical, mechanical, and flow in extreme environments, such as those encountered during transonic flight, hypersonic flight, and the terminal portion of weapons engagement

• Accurate, fast, robust, integratable models of the aforementioned that reduce requirements to test or help provide greater understanding of test results

• Advanced algorithms and computational techniques that are applicable to new generations of computers, including massively parallel, quantum, and neuromorphic machine

• Advanced algorithms and test techniques that allow rapid and accurate assessment of devices and software to cyber vulnerability

• New processes and devices that increase bandwidth utilization and allow rapid, secure transfer of test data to control facilities during test, with special emphasis on telemetry

• Advanced mathematical techniques that improve design of experiment or facilitate confident comparison of similar but disparate tests

• Advanced models of test equipment and processes that improve test reliability and efficiency

Prospective applicants who cannot find a suitable match in the advisor interest descriptions should apply under this broad description.

Air Force Test Center

SF.60.14.B1004: Computational Electromagnetics (CEM) for Predict of Electromagnetic Interference (EMI)

Johnson, M.

(850) 882-0970

Our research interests are related to Computational Electromagnetics (CEM). Realizing that a very large body of research exists addressing the topic at theoretical levels, I'm interested in understanding the application of CEM to very large problems, be them physically large structures or electrically large systems, ultimately to predict Electromagnetic Interference (EMI). Using CEM for large systems requires simplifications, assumptions, limitations that cause uncertainty in the answer. I am interested in methods to quantify those uncertainties to the greatest extent possible, or at least qualify them to a level that can be managed through risk assessments, application of margin, etc. Certainly the end goal is to reduce uncertainty to levels that no longer impact the use of the simulation for practical purposes. Since predicting EMI to aircraft components is impractical, I'm also interested in approximations and methods that can predict and quantify the likelihood of EMI to large systems. We are seeking highly-qualified and motivated individuals for collaboration in the advancement of current state-of-the-art methodology in specific research areas while enhancing the capabilities of tools employed by USAF to support test and evaluation.

Air Force Test Center

SF.60.14.B1006: Advanced Computational Algorithms for Characterizing Aircraft Aeroelastic Nonlinearities

Denegri, C.

(850) 882-0396

Research interests are in characterizing aircraft aeroelastic nonlinearities and development of theoretical prediction methodologies for flutter certification of real-world fighter aircraft. Advanced computational algorithms are needed to provide fast, accurate solutions to flutter related dynamics. Optimal use of HPC resources are often a concern due to the trades encountered in accuracy, speed, and performance, so techniques that identify the best algorithms for configurations and trade spaces under investigation are of high interest. We are seeking highly-qualified and motivated individuals for collaboration in the advancement of current state-of-the-art methodology in specific research areas while enhancing the capabilities of tools employed by USAF to support test and evaluation. Applicants that utilize current U.S. DOD and/or NASA codes will be given preference. Previous access to U.S. DOD HPC resources is also preferred.

Air Force Test Center

SF.60.14.B1007: High Performance Computing Physics-Based Aircraft and Flight Simulation Software

Morton, S.

(850) 882-1432

Research interests are in the areas of high angle of attack aerodynamics, maneuvering

flight simulation, massively parallel software architecture, aircraft system identification methods, and aeroelasticity. Current team includes four PhD's in aerodynamics and structures and two computer scientists, who are responsible for developing high performance computing (HPC) physics based aircraft simulation software. The software is a multi-disciplinary coupling of aerodynamics, structural dynamics, propulsion, and kinematics and kinetics. We have a high interest in developing and integrating accurate, robust, computationally efficient, physics-based algorithms and codes into HPC software used by the Air Force. We are seeking highly-qualified and motivated individuals for collaboration in the advancement of current state-of-the-art methodology in specific research areas while enhancing the capabilities of tools employed by USAF to support test and evaluation. Applicants that utilize current U.S. DOD and/or NASA codes will be given preference. Previous access to U.S. DOD HPC resources is also preferred.

Air Force Test Center

SF.60.14.B1008: Advanced Non-Destructive Inspection (NDI) Test Techniques

Bohun, M.

(937) 255-7210 x3639

Research interests are the application of Non-Destructive Inspection (NDI) Test techniques to quantify damage (i.e., fatigue cracking, fretting fatigue, wear) in aircraft landing gear components to include wheels, brakes and tires; as well as new innovative material development (i.e., metallic, composite or polymer) for improved corrosion, fatigue and lightweight damage tolerant designs to resolve design problems for landing gear applications or similar. Specific project concepts include:

• Materials development in low temperature polymer that expands under extremely low temperatures to seal aircraft wheel halves under low temp conditions ...may involve shape memory nano particulates/capsules within flexible polymer to seal wheel halves.

• Thermal Degradation of Composites. A thermal-effects database (developed over the past four years) requires attention in the form of DOE (ANOVA) data assessments to draw conclusions beyond those already reported. PhD assistance will be purely statistical in nature. Objectives of the tests were to determine thermal degradation thresholds (as evidenced by a decline in mechanical strength) in selected composite materials subjected to thermal flux of high-intensity and short duration, and to assess the ability of standard ultrasonic and advanced NDI methods to detect threshold levels of thermal degradation caused by high-intensity and short-duration heat flux.

• Resolve via Non-Destructive Inspection techniques the thermal profile within the tread of a dynamically rolling aircraft tire.

Air Force Test Center

SF.60.14.B1009: Modeling and Simulation for Operations Research

Polk, D.

(850) 884-1816

Given the emergence of technology and capabilities that transcend a single domain, or that should leverage two or more domains, the tools of operations research and modeling and simulation should be readily available to support real-time and longer-range decision processes at the strategic and operational levels of warfare. Better visualization of complex data sets and problems will help transmit knowledge - not just information - between the various interdisciplinary groups and leaders who plan and execute our strategies. Engineering, mathematical, probabilistic, and other scientific tools properly employed and adjudicated will improve decision making at all levels, but the greatest incremental impact would be at the strategic and operational levels. We would like to identify promising and successful approaches for modern analytical support, in the best tradition of operations research, to evaluation of viable warfighting alternatives using capabilities from multiple domains. Along with pointing the way to improving warfighting decision-making we would like insight into foundations for testing and training requirements and solutions that will provide systems, people, and processes best prepared for a truly integrated approach to USAF battle management.

Air Force Test Center

SF.60.14.B1011: Test Science and Engineering for the Space Environment

Nichols, J.

(931) 454-3542

AEDC’s space research interests includes space survivability, space weather, autonomic data processing, large volume data processing, space and signature models/validation, and image processing. We are interested in topics that advance and improve simulated space environmental capability for full-spectrum, realistic space systems and threat assessments. Specifically, we develop and validate advanced space analysis capabilities. We emphasize the following: (1) creation of new software algorithms for simulation of environmental variables; (2) modeling and simulation to understand the response of systems under test when exposed to space environments; (3) characterization of phenomena that could have a significant impact on the next generation space platforms and vehicles (e.g., missile interceptors, surveillance satellites); (4) development of unique analytical processes that provide valuable insight into test design and evaluation of mission data.

Air Force Test Center

SF.60.14.B1012: Sensor Arrays for Test Science and Engineering

Swanson, T.

(931) 454-4240

AEDC’s sensor array interests include advanced experimental design and M&S for testing large format sensor arrays. This research will support development of test methodologies and related software tools needed to test the more complex sensor systems. Infrared and visible sensor systems are increasing in complexity, including high-resolution focal plane arrays (FPA) with larger numbers of pixels, wide-field-of-view (WFOV) optical telescopes ranging from a fraction of a degree to tens of degrees FOV coverage, and broad spectral coverage with multispectral and hyperspectral applications. These developments are proceeding faster than ground-test facilities can be built or modified to test them. Current test methodologies that can test a sensor and its entire FPA of 256x256 pixels become impractical when considering and planning to test sensors with FPAs exceeding 2048x2048 pixels or sensors that consist of multiple FPAs combined and packed to create a mosaic of arrays. e.g., Current-generation infrared emitters are only 1024x1024 and considering the need for at least a two-to-one linear sampling ratio, it is obvious that sensor FPAs already exceed the ability to test using conventional full-coverage test methodologies. As the sensor FOV increases, it drives the need for increasingly larger and complex collimator projector optics in the test cell to fill the sensor's FOV. Given these realities and constraints, new testing methodologies combining optimal Experimental Design with M&S of facility and sensors are needed to effectively use existing test facilities in these new and more stressful regimes.

Air Force Test Center

SF.60.14.B1013: Hypersonic Boundary Layer Transition

Marineau, E.

(301) 394-1670

The research topic of interest is the instantaneous non-intrusive velocity measurements in hypersonic flow. As part of the TRMC/AFOSR Hypersonic Center of Testing Excellence, we are developing advanced non-intrusive instrumentation and performing experiments on large scale test articles to better understand hypersonic boundary layer transition, hypersonic turbulent boundary layers, and shock wave turbulent boundary layer interaction (e.g., provide new time resolved experimental data for the validation of direct numerical simulation [DNS], large eddy simulation [LES], and parabolized stability equations calculations). Hypersonic T&E facilities provide forces-and-moments and surface measurements required for the validation of computational tools used to extrapolate tunnel data to flight conditions. Although essential to quantify aero database uncertainties, current measurement capabilities provide a limited understanding of hypersonic flow physics. This understanding is essential to develop improved computational tools (e.g., advanced computation fluid dynamics codes) needed to reduce the technical risks of new hypersonic systems such as boost glide concepts currently being considered for Conventional Prompt Global Strike. Improved knowledge of flow physics requires instantaneous measurements of the velocity field, a capability currently not available in hypersonic T&E facilities. We are developing non-intrusive velocity measurements techniques to study hypersonic turbulent boundary layers and shock wave turbulent boundary layer interactions. Measurements of turbulent velocity fluctuations will be performed at Mach 10 on a large scale hollow cylinder flare for turbulent boundary layers and shock turbulent boundary layer interactions. Experimental results will be compared with state-of-the-art DNS and LES computations.

Air Force Test Center

SF.60.14.B1014: High-Fidelity CFD Modeling

Reasor, D.

(661) 277-8157

Our primary focus is on research of multi-disciplinary high-fidelity modeling and simulation rooted in computational fluid dynamics (CFD) and computational structural dynamics. We are seeking highly-qualified and motivated individuals for collaboration in the advancement of current state-of-the-art methodology in specific research areas while enhancing the capabilities of tools employed by USAF to support test and evaluation. Applicants that utilize current U.S. DOD and/or NASA codes will be given preference. Previous access to U.S. DOD HPC resources is also preferred. Opportunities for focused research include the following topics:

• The assessment of large-eddy simulation (LES) and hybrid (RANS-LES) turbulence modeling approaches for prediction of unsteady vortex-dominated, turbulent, transitional, and compressible flows over full-aircraft configurations through highlighting advantages and limitations via validation and verification. Specific unsteady phenomena of interest include: tail buffet, vortex breakdown, leading-edge separation, aeroacoustics, and shock-induced separation/wing buffet.

• Application of CFD-based hypersonic modeling and simulation to applied (e.g., high-speed precision weapon systems as well as manned and unmanned re-entry vehicles) problems that support real-world test and evaluation activities. Specific topics of interest include simulation of: aerothermoelasticity, chemically reacting near-body flows, shock-wave boundary layer interaction, aero-optical distortion, and ablating materials.

• Advancement of reduced-order modeling (ROM) techniques for aerodynamic, aeroelastic, and aerothermoelastic data sets in an effort to provide a near real-time prediction capability to test programs in a variety of flight regimes/conditions. Ideally, these ROM techniques would be applicable to M&S predictions, wind tunnel databases, and flight test results. Specific prediction capabilities sought include fast and accurate reconstruction of aerodynamic forces and moments (structural loads), temperature and heat-rate monitoring (thermal loads), and flowfield and surface property visualization.