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DoD 2013.A STTR Solicitation

Agency: Department of Defense
Branch: Air Force
Program/Year: STTR / 2013
Solicitation Number: 2013.A
Release Date: January 25, 2013
Open Date: February 25, 2013
Close Date: March 27, 2013
AF13-AT01: Multiphysics-based Sensor Fusion
Description: OBJECTIVE: To develop new multiphysics-based sensor fusion algorithms which map disparate sensor fields into a single common multiphysics-based representation. This model can then be used to produce higher quality sensor fusion data products. DESCRIPTION: The proliferation of sensor systems has created a large volume of multi-sensor data across a number of physical fields (e.g., optical, EO/IR, hyperspectral, polarimetric, acoustic/seismic, RF, electromagnetic, mechanical, thermal, electrical, radiation). Classical methods of combining disparate data normally involve highly nonlinear mapping between actual measurements and underlying parameterized target model [1]. Furthermore, each sensor source needs to be statistically characterized for a good joint estimation (fusion) to be performed. Unfortunately, the fields (and consequently the resulting measurements) can be so dissimilar that traditional combining methods (e.g., extended Kalman filtering) [2] may perform suboptimally due to approximations/assumptions required to map into conventional algorithms. Recent advances in physics modeling and efficient software simulations have given rise to the emerging field of multiphysics modeling [3], wherein a single unified physics representation of objects of interest is developed. In multiphysics-based sensor fusion, all sensor measurements are first mapped into a unified multi-field physics model, which is then used to generate estimates of parameters of interest. For example, an IR/RF/polarimetric sensor suite (maybe employed in an urban warfare setting by law enforcement) could be used to develop a multiphysics model for a set of objects (e.g., targets of concern and clutter (non-targets)), potentially producing more accurate parameters of interest. Additionally, advances in high performance embedded computing (HPEC) [4] make it possible to execute a number of multiphysics models in real-time, an enabler for tactical multiphysics-based sensor fusion. PHASE I: Identify relevant technological applications (e.g., biomedical, automotive, aerospace, acoustical, geo-mechanical, RF, robotics, machinery monitoring). Develop baseline multiphysics simulation models encompassing selected measurement observables. Derive multiphysics-based sensor fusion algorithms and demonstrate effectiveness using synthetic data sets. PHASE II: Further refinement and development of the multiphysics models and companion multiphysics-based sensor fusion algorithms. Conduct high fidelity demonstration/validation of algorithm performance, based on finer grained simulations. Develop baseline embedded computing approach for meeting tactical timeline requirements for chosen applications. Quantify performance gains relative to conventional fusion algorithms. PHASE III: This research is applicable across the entire DOD ISR enterprise. REFERENCES: [1] D. L. Hall, and J. Llinas,"An introduction to multisensor data fusion,"Proceedings of the IEEE, vol. 85, no. 1, pp. 6-23, 1997. [2] S. M. Kay, Fundamentals of Statistical Signal Processing: Estimation Theory, 1993: Prentice-Hall. [3] D. H. Rogers, and C. J. Garasi,"Prism: a multi-view visualization tool for multi-physics simulation,"Proceedings of the Third International Conference on Coordinated & Multiple Views in Exploratory Visualization, pp. 85-95, 2005. [4] J. R. Guerci, and E. J. Baranoski,"Knowledge-aided adaptive radar at DARPA: an overview,"Signal Processing Magazine, IEEE, vol. 23, no. 1, pp. 41-50, 2006.
AF13-AT02: Decision Making under Uncertainty for Dynamic Spectrum Access
Description: OBJECTIVE: Research, develop, and evaluate algorithms and technologies for Dynamic Spectrum Access (DSA) decision making under uncertainty. DESCRIPTION: Dynamic Spectrum Access (DSA) is emerging as one of the key technologies to enable the Department of Defense (DoD) to meet its increasing requirements for access to the electromagnetic spectrum [1]. DSA technologies seek to provide reliable, ad hoc access to sufficient capacity by secondary users while avoiding harmful interference to other spectrum users -- especially incumbent users. To accomplish those requirements, a DSA system must establish and maintain awareness with respect to the activity of other spectrum users as well as policies governing its access to spectrum. Awareness of in situ spectrum conditions will always contain significant degrees of uncertainty; therefore a DSA system must also make decisions under imperfect (incomplete and sometimes inaccurate) awareness. Recent and ongoing research has addressed nearly every aspect of DSA operation. Areas of significant research include spectrum sensing, multi-user access to spectrum, interference mitigation, security, regulatory frameworks, and economic considerations [2-4]. What has not been sufficiently addressed is the necessary ability to make decisions under uncertainty. Current DSA research does not include approaches for comprehensively expressing, managing, mitigating, and making decisions with imperfect awareness. Uncertainty is instead pre-factored into the formulation of regulatory rules; forcing DSA systems to sacrifice performance in the overwhelming majority of operating conditions in order to avoid rare cases (e.g., hidden nodes) leading to interference under nominal operating rules. Given a sufficient representation of knowledge uncertainty, DSA systems can make more reliable in-situ decisions under a broader range of scenarios and avoid performance loss. In this effort, the Air Force is soliciting innovative research proposals in the area of performance enhancement of DSA subject to uncertainty in current space spectrum use such as: non-existent spectrum usage data, unknown antenna side-lobe patterns, incomplete available satellite or earth station data set. Particularly, innovative algorithms and responsive technology development and demonstration for DSA decision making under uncertainty are of importance. First and foremost, uncertainty concepts must be embedded in the DSA knowledge base in a way that is scalable, enables distributed operations, and is compatible with awareness information sources. Second, an evaluation capability must synthesize DSA performance goalscapacity, interference, and costwith uncertainties in the knowledge base. Finally, awareness management mechanisms must reduce awareness uncertainties by combining information from a range of data sources including sensors, semi-static databases, and underlying network control data. PHASE I: Select a Low Earth Orbit satellite communication scenario entailing crosslink pattern design, partitions of satellite footprints, inter-satellite links with user to user delays and link margins, precedences for spectrum sharing with Geostationary Orbit satellites. Detect/track interferences using passive angle data. Identify effective approaches & algorithms for DSA subject to imperfect knowledge. PHASE II: Refine the Phase I algorithm/system concept. Demonstrate DSA benefits for inter-satellite links'channel capacities under contested environments. Assess utility of the technology against spectrum re-using/harvesting/sharing, inter-satellite link routing paths for given QoS requirements, intentional/un-intentional interference mitigation, reconfigurability of inter-satellite links to meet end-to-end traffics. Quantify spectrum availability for LEO/GEO downlinks/uplinks & user-to-user time delays. PHASE III: Dynamic DSA technologies are applicable to High Data Rate Airborne Terminal and XG DSA2100 with improvements in capacities and flexibilities. In addition, spectrum occupancy measurements are useful to multi-organizational urban surveillance networks, disaster response networks and cellular networks. REFERENCES: 1. S. Chan,"Shared spectrum access for the DoD", IEEE Communications Magazine, Vol. 45, No. 6, pp. 58-66, 2007. 2. Q. Zhao and B. Sadler,"A survey of dynamic spectrum access,"IEEE Signal Processing Magazine, Vol. 24, No. 3, pp. 7989, 2007. 3. Presidential memorandum: Unleashing the wireless broadband revolution. In Federal Register, Vol. 75, No. 126 of Presidential Documents, pp. 3838738389. US Government Printing Office, Washington, DC, 2010. 4. National Broadband Plan: Analysis and Strategy for Connecting America. NOVA Science, New York, 2011.
AF13-AT03: Development of high power wavelength division multiplexers
Description: OBJECTIVE: To advance the power handling capability of Wavelength Division Multiplexers (WDM) in both PM and non-PM fiber. DESCRIPTION: Separate fibers into the core of a single fiber. The WDM works by first collimating the light from each fiber. The collimated beams, which are combined using a dichroic filter, are then focused into the output fiber. The WDM can also be run in reverse and used to separate two wavelengths of light from a single fiber into two separate fibers. Most development of WDMs has been done to support the lower power telecommunications industry. Such WDMs use traditional step index silica based fiber and typically have at most, a power handling capacity of 10 W. This is a major limiting factor for numerous high power laser applications to include two tone seeded lasers, seeded Raman lasers for high power operation, etc. There is a need to develop WDMs of increased power handling capacity of up to 150 W in traditional step index fiber at the wavelengths required for the various high power applications. WDM manufacturing technology needs to support the common fiber sizes to include 6/125, 10/125, and 20/400 fiber as well as polarization maintaining and non-polarization maintaining fiber. Besides traditional step-index fiber, there is also a need to develop high power WDMs in photonic crystal fiber (PCF) to support high power applications. PCF, which is uniform along its length, has a cross-section consisting of one or more materials in the form of hexagonal rods arranged periodically over the cross-section. Surrounding the core is a cladding which consists of a hexagonal lattice of air holes. This material is vastly different from traditional step-index fiber. WDMs in this material will involve fibers having a larger core than those found in traditional step-index fiber. In addition, WDM technology in photonic crystal fiber needs to have a power handling capability of 200 W and needs to support both polarization maintaining and non-polarization maintaining fiber. PHASE I: 1. Feasibility of various manufacturing techniques to produce WDMs in PM and non- PM step index fiber such that the power rating is 10 W for 6/125 fiber, 100 W for 10/125 fiber and 200 W for 20/400 fiber. 2. Feasibility of various manufacturing techniques to produce WDMs in PM and non- PM photonic crystal fiber such that the power rating is 150 W for a seven rod core. PHASE II: 1. Develop a technique to manufacture WDMs having high power ratings in both PM and non-PM traditional step index fiber. Deliver five PM WDMs capable of combining 1121 and 1178 nm in 10/125 fiber with a power rating of 100 W and five PM WDMs capable of combining 1069 and 1178 nm in 20/400 fiber such that the power rating is 200 W. 2. Develop technique to manufacture WDMs in PM and non-PM PCF. PHASE III: Continue development of WDMs in step index and PCF in order to meet the delivery specifications. REFERENCES: 1. Photonic crystal fiber: Russell, et. al., Journal of Lightwave Technology 24(12)(2006)4729. 2. WDMs in PCF: Liu, et. al., Optics Letters 36(14)(2011)591. 3. WDMs in general: 4. Classic paper on a WDM: Digonnet, et. al., IEEE Journal of Quantum Electronics 18(1982)746.
AF13-AT04: Nonequilibrium Plasma-Assisted Combustion-Efficiency Control in Vitiated Air
Description: OBJECTIVE: To investigate electrical control of selective energy deposition for significant modification of combustion kinetics through nonequilibrium thermochemistry and induced flow. DESCRIPTION: Combustion efficiency, reignition and flame holding are important issues for both very high-altitude and high-speed flights. High-altitude jet engine operation is limited by the overall combustion efficiency and the lean flame blow out (LBO) limit. Similarly, the need to improve fuel efficiency and reduce emissions from hydrocarbon combustors has also reinvigorated interest in active monitoring and improving control [1] of LBO. New augmentor designs need to reduce exhaust gas temperatures to improve mission capability, leading to high air mass flow through the augmentor. Short residence time of the gas flow and reactant mixing time leads to two types of combustion instability in augmentors; low-frequency rumble for high-altitude, low-Mach number flights, and high-frequency pressure fluctuation during low-altitude, high-Mach number flights [2]. Combustion instability of a lean flame arises from the balance between the heat generation and the heat loss rate through conduction, convective, and radiative losses. The heat generation rate in a binary reaction is given by HQ=r2c1c2Qexp[-e/RT], where r is the density, c1 and c2 are mole fractions of the reactants, Q is the reaction heat release, e is the activation energy, R is the gas constant, and T is the average temperature in K. For hydrocarbon-air oxidation reactions, the typical value of e>>RTf, where Tf is the adiabatic flame temperature, so most heat release reactions are confined to a thin reaction sheet, where the gas temperature reaches its maximum value. The maximum gas temperature in a combustion zone is dependent on the fuel-air ratio. The lean flame burning condition is, therefore, more susceptible to the combustion instability because of a narrower operating window and strong feedback between the heat generation and the heat loss rate. Either preheating the upstream gas or radical injection can increase flame speed [3,4] by reducing the activation barrier of hydrocarbon oxidation reactions, improving the heat release rate and flame stability. Zero-dimensional chemical kinetic model calculations predict that nearly 1% fuel dissociation is required to enhance combustion [3,4]. These calculations are consistent with the H atom radical depletion reaction with the fuel. In a premixed flame, the cross-over temperature is defined by the condition where radical production is balanced by radical depletion. Therefore, for flame propagation it is necessary for fuel to be depleted, which usually defines the location of the reaction zone. The use of electrical energy input to modify combustion kinetics has been pursued since the 1970's. Those early research results are described by Bradley [6]. Recent advances in non-equilibrium high E/n plasma generation, where E is the electric field and n is the gas density, at high pressure have prompted research on the application of energy-efficient radical production to enhance hydrocarbon-air combustion [7-9]. The direct electron impact dissociation of hydrocarbon fuel and/or O2 molecules produces radicals with very low reaction activation barriers for fuel oxidation, e.g., O2+e -->2O+e, leading to CnHm+O -->CnHm-1+OH and CnHm+OH -->CnHm-1+H2O (and other similar sets of reactions with partially dissociated fuel) initiating heat release below the typical cross-over temperature required for thermal dissociation of fuel and oxidizer. Similar low activation energy reactions are also possible by electron impact dissociation of hydrocarbon CnHm+e -->CnHm-1+H+e, where a chain propagation reaction H+ O2 -->OH+O can be initiated at lower gas temperature than under thermal equilibrium kinetics. A properly designed nonequilibrium plasma source could, therefore, possibly enhance combustion kinetics and reignition under normally adverse condition. The investigation of the scaling laws of nonequilibrium plasmas for energy efficient radical production is relevant for improving combustor operating conditions over a wider range of operating conditions than currently feasible. The contractor shall quantify the effects of nonequilibrium plasma chemistry on both flame speed increase and flame holding improvement, especially in vitiated air. Quantitative optical spectroscopic measurements should be performed to measure heat release rate or gas temperature modification by nonequilibrium plasma kinetics. As discussed above, quantitative measurements of super-thermal H atom, O atom, and OH radicals are essential for combining plasma kinetic models with combustion kinetic models to develop a predictive capability for non-thermal plasma-assisted combustion efficiency improvement in vitiated air and in high-altitude operation of turbine engines. Also, volume and pressure scaling properties of high reduced electric field plasmas produced by high-voltage short time duration pulse excitation will be quantified by accurate measurements of energy deposition efficiency in various hydrocarbonair gas mixture plasmas. PHASE I: Demonstrate quenching-corrected measurements in a laboratory-scale non-equilibrium plasma-assisted combustion rig in 2D imaging capability, by key plasma-chemical radical and intermediate species concentrations (O, H, & OH). The approaches should for high precision and accuracy, including mitigation of undesirable photolytic or other interfering processes, and strategies for absolute calibration. PHASE II: Develop and demonstrate quenching-free measurements of heat-release rate in a turbulent reacting-flow environment assisted by plasma ignition, to be performed along with the key radical species described in the Phase I activities. Use experimental data to validate a plasma-assisted combustion kinetic model. Solve laser optical and molecular with mass spectroscopic for reactive species obtianed during initiating of hydrocarbon chain branching reactions at gas temperatures below 800 K. PHASE III: The developed experimental methods and the validated model can be used for the development of next generation war fighters capable of flying at higher altitudes or significantly higher speeds. Capabilities are useful to the engine manufacturer for development of high-altitude propulsion vehicles. REFERENCES: 1. N. Docquier and S. Candel, Progress in Energy and Combustion Science 28, 107 (2002). 2. W. Krebs, P. Flohr, B. Prade, and S. Hoffmann, Combust. Sci. Tech.174, 99 (2002). 3. K. Takita, G. Masuya, T. Sato, and Y. Ju, AIAA Journal 39, 742 (2001). 4. Y. Ya. Buriko, V. A. Vinigradov, V. F. Goltsev, and P. J. Waltrup, J., Propulsion and Power 16, 1049 (2002). 5. F.A. Williams, Progress in Energy and Combustion Science 26, 657 (2000). 6. D. Bradley in: F. J. Weinberg, (ed.) Advanced Combustion Methods, Academic, New York, 1986. 7. W. Kim, M. G. Mungal and M.A. Cappelli, Combust. Flame 157, 374 (2010). 8. A. Starikovskiy, AIAA 2012-0828, 50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, 9-12 January 2012, Nashville, TN. 9. I. V. Adamovich, I Choi, N Jiang, J-H Kim, S Keshav, W R Lempert, E Mintusov, M Nishihara, M Samimy and M Uddi, Plasma Sources Sci. Technol. 18 034018 (2009).
AF13-AT05: Security in Cyber-Physical Networked Systems
Description: OBJECTIVE: Investigate challenging security issues in Cyber-Physical Networked Systems. DESCRIPTION: A cyber-physical system (CPS) is a system featuring a tight combination of, and coordination between, the system"s computational and physical elements. Today, a pre-cursor generation of cyber-physical systems can be found in areas as diverse as emerging and future combat systems, air-space-cyber activities, as well as smart buildings, bridges and other structures. To interact with physical system, the geographically distributed sensors, actuators, and controllers are interconnected via the communication networks. In particular, sensor nodes obtain the measurements from physical world and send data to the controller through computer networks. The controller then obtains the states of physical systems and sends control commands to the actuators to adjust it operation. Before CPS can be used, the security of CPS must be fully understood and addressed. There are a few challenges. First, the military CPS may operate in hostile environments. The sensor and actors lacking tamper-resistance hardware may increase the possibility to be compromised and further disrupt the mission of CPS. Second, the next generation CPS must interwork with existing physical infrastructure, which are composed a large number of legacy devices. Those legacy devices were developed many years ago and do not have appropriate security mechanisms in place. Third, the next generation CPS generally demands high performance guarantee with real-time requirements to enable operation stability. Hence, design and development of effective and low cost defensive mechanisms to detect and localize malicious devices become critical issues in CPS. PHASE I: Develop and demonstrate threat models for a selected CPS. Investigate associated vulnerabilities and impact to the CPS operations. Develop defensive algorithms that automatically assess emergent situations of the large-scale cyber networks and mitigate potential impact of attacks (including stealthy attacks) in CPS of choice. Proof-of-feasibility demonstration enables the concepts. PHASE II: Refine the technical assumptions and proof-of-concept. Develop, demonstrate, and validate a prototype that implements the Phase I findings. Identify appropriate performance metrics for extensive evaluation. PHASE III: Secure CPS will be indispensable to DoD network centric warfare and mission assurance. This technology will provide foundations to build more secure systems in areas of autonomous space, air and ground systems as well as smart grids, intelligent transportation systems, health care and robotics. REFERENCES: 1. Lee, Edward (January 23, 2008). Cyber Physical Systems: Design Challenges. 2."NSF Workshop On Cyber-Physical Systems". 3."Beyond SCADA: Networked Embedded Control for Cyber Physical Systems".
AF13-AT06: High specific power and cost effective solar array for spacecraft, lighter than air vehicles, and UAVs
Description: OBJECTIVE: Develop and demonstrate a 2 100 W radiation hardened solar array adaptable to nanosatellites exhibiting flexibility, variable topology, high specific power and low cost. DESCRIPTION: Satellite power systems designs are trending towards"the large as possible"types of satellites with power system mass allocations of approximately 200 kg down to nanosatellites with volume constraints based on the"3U"concept requiring a 10 cm x 10 cm x 34 cm volume constraint. Both ends of this spectrum of satellite sizes have traditionally relied upon the use of high efficiency monolithic multijunction photovoltaic (PV) technologies to provide power to the electrical bus whose solar array specific power on the order of 80 100 W/kg, and cost rates for the solar array as high as $350/W. The use of high efficiency solar cells to populate arrays limits overall power to approximately 30 kW for large satellite systems, and is reportedly and surprisingly a cost limiter for nanosatellite systems. In the interest of enabling substantial gains in power available to spacecraft, thin film photovoltaics will be considered in this topic. Recent technology advances in the area of thin film photovoltaic arrays offer a solution to the mass and stowable volume limitations of high power arrays. Thin film arrays, even with efficiencies of only around 9-12%, are so lightweight that they offer specific powers in excess of 1,000 W/kg - a factor of ten or more above the current state of the art for inorganic cells. Since these arrays are deployable, they can be packaged with minimum mass and volume, and readily deployed in space with near-term demonstrable technologies. In fact, laboratory test cells have been produced by Institut de Microtechnique at the University of Neuchatel, Switzerland using LaRCTM-CP1 thin-film substrates produced by SRS Technologies in Huntsville, AL that have the highest power/mass ratio on record - 4300 W/kg![6] These thin film arrays can be stowed in a rolled or folded configuration in the launch vehicle and deployed in space by simple boom extension or roller mechanisms. A well-designed 50 kW space solar array and deployment system using rolled mechanisms with this specific power would weigh 32 kg with a payload volume the size of a suitcase. This low mass and payload volume, combined with high power density, can provide 50 kW+ space solar arrays at 25% of the cost of current rigid solar arrays. Regarding suitability to the space environment, recent AFRL test and characterization programs have shown that even organic-semiconductor-based photo-cells may be usefully employed as power sources in space, particularly for short-lifetime, rapidly-assembled, low earth orbit (LEO) missions. Though they too exhibit disadvantages over typical inorganic based cells (e.g., low photo-conversion efficiency (<8%)), their specific power is substantially higher given the thin film, low mass nature of the cells. One can easily imagine their incorporation on the body of a satellite itself or on the surface of an inflatable, easily deployed structure. The goal of this project is to develop a thin film deployable solar array utilizing thin film photovoltaics either body mounted or tethered, to provide power to a nanosatellite system. PHASE I: The contractor shall design and demonstrate an organic solar cell that is suitable for nanosaellite application with adequate radiation hardness and power/weight efficiency. The overall design should take into account of all parameters (e.g. stow volume, deployment scheme) to ensure that the ultimate system will be deployable for said applications. PHASE II: The contractor shall design, fabricate, test and demonstrate the thin film photovoltaic based power system including the photovoltaics, the deployment system, any tracking system (if necessary). If possible, the contractor shall provide system for a nanosatellite designer for use. PHASE III: Extend the design and develop deployment, tracking, and control systems necessary to deploy large thin film photovoltaic based power systems for satellite missions. REFERENCES: 1. K. Reed and H. J. Willenberg,"Early Commercial Demonstration of Space Solar Power Using Ultra-lightweight Arrays,"Space Future, 2. A. Q. Rogers and R. A. Summers,"Creating Capable Nanosatellites for Critical Space Missions,"
AF13-AT07: Compact Pulsed Power Source for High Repetition Rate Applications
Description: OBJECTIVE: To develop a high power, nanosecond power source that operates continuously at a high repetition rate for propulsion, directed energy, and energy production systems. DESCRIPTION: High peak power, nanosecond pulsed power sources are a enabling technology for a wide number of applications. Performance gains occur for a number of reasons depending on the application. Examples include: 1) macroscopic and microscopic non-equilibrium plasmas created by nanosecond discharges; and 2) soliton formation on dispersive, nonlinear transmission lines. In the first example, higher energy, beam-like electrons in plasma streamers, rather than thermally equilibrated electrons, can be employed to create reactive species that favorably alter chemical reactions for a range of applications from combustion ignition, ozone production, and even medical applications. In the second example, high frequency solitons generated by solid state architectures show promise for enabling compact, microwave sources that are significantly lighter and more reliable than existing technology for directed energy applications. For the nanosecond power sources to compete with existing technology they must meet a number of stringent specifications; common ones being that the source be compact, lightweight, and reliable. While compact sources based on solid state technology have been reported in the literature, most of these are not capable of operating at the conditions required by real world applications. There is need for a new class of systems capable of producing pulses at sustained high repetition rates in order for these applications to realize their potential. The purpose of this topic is to investigate issues associated with developing a nanosecond source that runs at repetition rates of at least 100 kHz, and to build a prototype that can operate continuously under these conditions. Key issues of this topic include increasing system efficiency; understanding the effect of temperature on the constitutive parameters of dielectric, magnetic, and semiconductor materials including frequency dependent loss; limits of material performance with respect to electrical breakdown and melting, and optimizing active/passive component cooling. An additional consideration, given the short pulse nature of the discharge waveform, is consideration of electromagnetic interference and compatibility such that these new pulsed power systems avoid wreaking havoc on other electrical components in the system. Therefore, attention to shielding is necessary for development of practical systems. PHASE I: Phase I effort should combine results from material testing and modeling at the device and system levels with experimental results to build a laboratory demonstration unit capable of operating at 20 kHz into suitable loads at voltages above 10kV. Verification and validation of the design protocol should be demonstrated during this effort. PHASE II: Based on insight gained from the designing and testing the prototype unit, develop a full scale system that reliably generates pulses with parameters useful for the applications mentioned above (amplitude greater than 50 kV, FWHM between 10 and 100 ns, repetition rate greater than or equal to 100 kHz). Unit should be able to interface with power sources standardly available in military vehicles, and provide isolation of electromagnetic interference to external system. PHASE III: System adoption for commercial and military applications. Examples of application areas include internal combustion engines for increased efficiency; combustion for diesel and gas turbine engines; reduced ignition delay in pulsed detonation engines; plasma assisted flow control to reduce drag. REFERENCES: 1. E. Schamiloglu et. Al."Modern Pulsed Power."Proc. IEEE, vol. 92, 1014 (2004). 2. J.A. Gaudet et. Al."Research issues in developing compact pulsed power for high peak power applications on mobile platforms."Proc. IEEE, vol. 92, 1144, (2004). 3. D.A. Singleton et. Al."Compact Pulsed-Power System for Transient Plasma Ignition."IEEE Trans. Plasma Sci., vol. 37, 2275 (2009).
AF13-AT08: Secure Efficient Cross-domain Protocols
Description: OBJECTIVE: Develop cross-domain protocols and design methodologies to enable distributed applications to operate securely when split between two security domains. DESCRIPTION: Coordination of activities between different security domains remains a thorny and yet crucial problem. Cross domain data flows impeded by time-consuming release procedures prevent fluid and effective operations. The situation also encourages the entire activity to be carried out at the highest security level to avoid sharing the data between security domains. This solicitation envisions a future information architecture in which distributed applications can be split between domains, with the parts communicating via a trusted automated guard. Such applications would serve to coordinate activities and maintain data consistency between domains. Such split applications would also reduce the need for ad hoc forms of communication between the domains, whose security is difficult to ensure. Critically, such applications must not enable unintended flows of information between domains. Thus, this solicitation focuses on the design of the protocol which ties the two parts of the application together as the key challenge. As an example, consider a workflow that requires some tasks to be performed in each domain. Automation of such a workflow would require communication between domains for control flow (to coordinate the tasks) and data flow (to transfer results from one task performer to another). The cross domain guard will be a third participant in these protocols, examining each message, with the capability of blocking or altering messages and even generating fresh messages. Thus, software for the protocol (or class of protocols) must be incorporated into the guard. This solicitation seeks two kinds of developments: 1. Protocols or classes of protocols of practical interest to the Air Force that can be securely operated between security domains, and/or 2. Practical means for determining that instances and implementations of such cross domain protocols are secure and correct. The two main parts of the application should run without special privileges in their domains. However, the module that interprets the protocol within the guard is highly privileged, and therefore the highest degree of trust in its correctness and security is of key importance. This component of the system must either be very simple so that manual inspection is feasible, or there must be some other means or strategy for ensuring correctness. Assume that the straightforward operation of the distributed application for its intended purpose is well within the security policy. This solicitation focuses on ensuring that the protocol cannot also serve as a conduit for covert communications, or that the bandwidth of such covert channels is limited. Respondents should describe what kind of protocol their system will support, what sorts of cross-domain applications that protocol will enable, and what the overall usefulness of such applications would be in a cross domain setting. Respondents should also indicate why it is at least plausible that their selected class of protocols will be secure in the sense described here. Of particular interest will be theoretical advances that enable larger classes of protocols to be handled securely or that enable automated analysis of protocols to ensure that they are secure with mathematical accuracy. PHASE I: Define class of protocols operating across domain boundary with strategy for protecting protocol as it passes through a guard. Provide security argument/analysis that shows a bandwidth limit on covert channel that could be supported by this protocol. Alternatively, determine if selected member of protocols class has limited/0 covert channel capacity. Prove class of such protocols is nonempty. PHASE II: Based on the work of Phase I, implement tools to support the class of protocols selected including the guard component, and any automated protocol analysis that is necessary to ensure security. Construct a sample cross domain application using a protocol from that class that meets security requirements. Illustrate the security argument in concrete form for this application. PHASE III: Solve multi-domain coordination problem for a military customer. Work with automated guard vendor to install and test protocol checking module. Apply technique to protect communications between E-systems & cloud services. Integrate guard component using firewall appliance. REFERENCES: 1. John McHugh, Covert Channel Analysis, in Handbook for the Computer Security Certification of Trusted Systems. Available at 2. Susan Older and Shiu-Kai Chin, Formal Methods for Assuring Security of Protocols, The Computer Journal, Vol. 45, No. 1 2002. Available at 3. Nikhil Swamy, Michael Hicks, and Simon Tsang, Verified Enforcement of Security Policies for Cross-domain Information Flows, Proceedings of the Military Communications Conference, 2007 (MILCOM 2007) Orlando, FL, pp. 1-7. Available at
AF13-AT09: Microvascular Composites for Novel Thermal Management Devices
Description: OBJECTIVE: To develop high-performance thermal management devices based on multifunctional design of microvascular composite materials and thereby to allow a precision control of the network passages tailored to specific cooling applications. DESCRIPTION: Compact, efficient heat exchangers enable improved operation of many thermal management devices such as Joule-Thomson (J-T) coolers. Most J-T heat exchangers are either metal finned-tube devices with limited surface area between the solid and gas streams, or etched-glass/silicon devices that allow relatively limited gas flow and cooling power. A micro-capillary array based heat exchanger offers the potential for both large surface area and large gas flow, with a manufacturing process that offers low-cost mass production. Within this context, novel microvascular composites recently developed offer precision control of the network passages tailored to specific cooling applications with textile weaving techniques allowing incorporation of high-performance structural fibers simultaneously. Underpinning this method is the efficient thermal depolymerization of catalyst-impregnated polylactide fibers with simultaneous evaporative removal of the resulting lactide monomer. The hollow channels produced are high-fidelity inverse replicas of the original fiber"s diameter and trajectory. This method has yielded microvascular fiber-reinforced composites with channels over one meter in length that can be subsequently filled with a variety of liquids and gases. PHASE I: Demonstrate the scaled-up fabrication of microvascular composites with the mechanized weaving of sacrificial fibers into 3D woven glass fiber performs and subsequent vaporization of sacrificial components. Establish new design concepts of varying the position, length, diameter, and curvature of fibers forming microchannels. PHASE II: Develop multifunctional structures of microvascular composites with 200-500 micron diameter parallel channels nested in close proximity to produce a counter-flow heat exchanger. Demonstrate how to circulate the microvascular network with a fluid having the desired physical properties. Assess whether the performance of the J-T heat exchanger made of microvascular composites can be enhanced by incorporating carbon fibers of highly anisotropic thermal conductivity. PHASE III: Applications include IR sensors for target tracking for use in both commercial and military aircraft. Evaluate the cooling performance of prototypes under mechanical stress and introduce remedies to avoid undesirable malfunctioning. Conduct manufacturing and testing program to ensure service life. REFERENCES: 1. A. P. Esser-Kahn, P. R. Thakre, H. Dong, J. F. Patrick, V. K. Vlasko-Vlasov, N. R. Sottos, J. S. Moore, S. R. White. Three-Dimensional Microvascular Fiber-Reinforced Composites, Advanced Materials 23:3654-3658 (2011). 2. Y. Fan, H. Nishida, T. Mori, Y. Shirai, T. Endo. Thermal Degradation of Poly(lactide): Effect of Alkali Earth Metal Oxides for Selective L,L-Lactide Formation. Polymer 45(4):1197-1205 (2004). 3. V. Natrajan, K. Christensen. Non-intrusive Measurements of Convective Heat Transfer in Smooth- and Rough-Wall Microchannels. Part I: Laminar Flow. Experiments in Fluids, 49 (5):1021-1037 (2010).
AF13-AT10: Next Generation Tracking Architectures for Urban Surveillance Areas
Description: OBJECTIVE: Develop and implement next generation tracking architectures which exploit wide area motion imagery and leverage projected High Performance Computing capacities. DESCRIPTION: Wide area motion imagery (WAMI) systems, such as the Autonomous Real-time Ground Ubiquitous Surveillance - Imaging System (ARGUS-IS), produce tens of thousands of moving target indicator (MTI) detections from city- size urban areas (over 40 square kilometers) at video rates of greater than 12 Hz. On-board processing currently provides a limited number of operator-nominated real-time Stationary Video Windows (SVW) and Tracking Video Windows (TVW) for target monitoring and engagement. Off-board processing currently provides a much greater number of automated tracks for forensic analysis but only for a partial portion of the urban surveillance area (Reference 1). To improve mission effectiveness, the on-board number of real-time targets monitored and engaged needs to be significantly increased and the off-board forensic analysis portion of the urban surveillance area needs to be dramatically expanded. Thus, innovative next generation track processing architectures are needed to fully exploit the revolutionary advances being achieved by WAMI systems with regard to target detection and surveillance area capabilities. As the densities of the surveillance areas have increased (from rural, to suburban, and ultimately to urban), it has become especially challenging for current generation track processing architectures to correctly and efficiently associate individual MTI detections with vehicle and dismount targets. For example, Multiple Hypothesis Tracking (MHT) has been deployed to address dense environments by forming and maintaining hypotheses until sufficient confidence is achieved to declare an association. However, current MHT"s are limited by the density of the surveillance areas as the track processing requirements grow exponentially as a function of the total number of targets and their relative proximities. Other current track processing architectures such as Particle Filtering and Joint Probabilistic Data Association are also severely challenged by urban surveillance areas. A potentially rewarding avenue of investigation is the future relationship of target density and High Performance Computing (HPC) capacities with target density having reached an upper bound (i.e. only so many vehicles can be on a roadway; even in an urban traffic jam) whereas HPC processor developments and associated capacities are projected to be unbounded (i.e. multicore processors and distributed databases; for handling Big Data). While these future HPC capacities may extend current tracking architectures which are based on target trajectory modeling; more importantly, they can potentially enable next generation tracking architectures which may be based on higher level multiple-target activity modeling which focuses on correlations of appearance events at the pixel level identified through various learning methods. These pixel-level approaches can be sensitive to imagery noise, etc. and can be computationally demanding due to the large number of pixel-level events which need to be continuously and simultaneously monitored and detected (Reference 2). PHASE I: Develop a prototype next generation tracking architecture which exploit wide area motion imagery (WAMI) systems and leverage projected High Performance Computing (HPC) capacities for on-board and off-board processing of vehicle and dismount targets within urban surveillance areas. PHASE II: Determine feasibility of next generation tracking architectures and demonstrate representative implementations of on-board and off-board processing through utilization of a High Performance Computing Environment which includes interactive computing resources, enhanced data management capabilities, and increased data storage. PHASE III: Exploitation of WAMI over adversarial urban surveillance areas provides for timely target engagement and more comprehensive forensic analysis. Exploitation of WAMI over domestic urban surveillance areas provides for timely emergency response and more comprehensive disaster monitoring. REFERENCES: 1. Leininger, Brian et. al. of DARPA, Edwards, Jonathan et. al. of BAE Systems (2008). Autonomous Real-time Ground Ubiquitous Surveillance Imaging System (ARGUS-IS). Proc. of SPIE Vol. 6981. 2. Xiang, Tao, and Gong, Shaogang of Department of Computer Science, Queen Mary, University of London (2006). Beyond Tracking: Modeling Activity and Understanding Behavior. International Journal of Computer Vision 67(1), (pp. 2151). 3. HPCMP Enhanced User Environment Begins Production Operations.
AF13-AT11: Enhancing the Scaling and Accuracy of Text Analytics Using Joint Inference
Description: OBJECTIVE: To conduct basic research and define and evaluate algorithms which perform joint inference for the purpose of enhancing the performance of deep Natural Language Understanding (NLU). DESCRIPTION: A key goal of deep Natural Language Understanding (NLU) is to understand the sophisticated relationships that can be expressed in text both explicitly through explicit phrases like"John Married Mary in 2002", but also through implicit information that we gain from performing inference across several relationships, e.g.,"Mary was divorced in 2007 and goes by her maiden name Mary Smith". From this information, we discover a non-obvious co-reference and that John (referenced above) is also divorced. To accomplish this task, successful NLU systems need to extract multiple relations (e.g., both marriage and divorce) and possess relevant domain knowledge (e.g., the fact that divorce ends marriage and is symmetric). Recent years have seen an explosion of successes in combining probability and (subsets of) first-order logic respectively. First order logic handles complexity and probability handles uncertainty. Traditional AI has inevitably overtaxed resources when scaling up the environment. Inference has been the biggest bottleneck for the use of Statistical Relational Learning (SRL) Models in practice. Inference in SRL Models is very hard. These properties have led to a surge in interest in lifted probabilistic inference algorithms that exploit redundancies to speed-up inference, ultimately avoiding explicit state enumeration by manipulating first-order state representations directly. Therefore, inference becomes a crucial issue due to learning becoming harder and the greater complexity for users. Lifted inference, not grounded, in first order logic is often faster, more compact and can provide more structure for optimization. Lifted inference deals with groups of random variables at a first order level and possesses the ability to carry out probabilistic inference in a relational probabilistic model without needing to reason about each individual separately. Lifted inference has the potential to exploit interchangeability in a domain, queries can be returned without instantiating all the objects in the domain and it exploits shared correlations and symmetries in the data and model, while receiving and sending the same message. The use of Joint inference to improve deep Natural Language Understanding can form the basis to represent a large variety of linguistic information about articles in one logic-based, formal notation. Methods, like probabilistic logic, can be applied for learning and reasoning. Research needs to be performed to evaluate the various lifted inference methodologies and techniques and evaluate not just how well the performance but against what requirements. Lifted inference contains both graph based and search based criteria. The graph-based implementations include exact, approximate and pre-processing subgroups. The approximate subgroup can be further quantified as deterministic approximation, sampling and interval methods. Examples of lifted exact inference are lifted variable elimination (VE), lifted VE plus aggregation, Bisimulated VE and First Order VE (FOVE). Example of Lifted Pre-processing Inference is Fast Reduction of Grounded Markov Logic Networks (MLNs) (FROG). Example Lifted interval Inference is Anytime Belief Propagation (BP). Examples of Lifted sampling inference are MCMC techniques, logic particle filter and lazy inference. PHASE I: Study: (1) Scalability of the different lifted inference techniques (2) Trade-off between use of background knowledge to improve the final results versus the effort required to encode such knowledge (3) Performance versus different kinds of problems (4) Evaluate the performance and scalability of the different techniques for joint inference at the cross-document or corpus level PHASE II: Leverage the results from phase I to develop a framework to perform text analytics over an information repository using the various reasoning and learning approaches to joint inference. Demonstrate the capabilities on an end-to-end prototype to perform tasks like answering specific queries without considering the entire model and/or the entire evidence. Demonstrate joint inference over cross-document and multiple knowledge bases. Explore combining lifted inference with dual decomposition. PHASE III: The algorithms for Lifted inference have a variety of applications. They include social networks, object recognition, link prediction, activity recognition, model counting, bio-medical applications and relational reasoning and learning. Fundamental building block to improve current capabilities. REFERENCES: 1. Tutorial on Lifted Inference in Probabilistic Logical Models, Twenty-second international joint conference on Artificial Intelligence (IJCAI) 2011. Kersting, Natarajan and Poole. 2. Efficient Inference Methods for Probabilistic Logical Models, Sriraam Natarajan, University of Wisconsin-Madison, at 3. Markov Logic: An Interface Layer for Artificial Intelligence By Pedro Domingos, Daniel Lowd, Morgan & Claypool Publishers, Aug 15, 2009
AF13-AT12: Physical Sub-Model Development for Turbulence Combustion Closure
Description: OBJECTIVE: Development of physics-based models and associated modules and libraries for turbulence combustion closure for combustion regimes of relevance to the Air Force. DESCRIPTION: Turbulent combustion phenomena are crucial for the prediction of the stability and performance of many practical combustion systems. This topic is focused on the development of physics-based turbulent combustion closure schemes for pre-mixed, non-premixed and partially premixed flames for all flow and chemistry regimes. A number of turbulent combustion models have been proposed in the literature ranging from the early eddy break-up models to work involving flamelets, PDF-based approaches, the Linear-Eddy Model, and so on [e.g., Refs. 1-5]. Despite this progress, the general state-of-the-art of turbulent combustion models in widely available reacting flow codes remains inadequate. Of particular interest is the formulation of turbulent combustion models in the context of high-resolution Detached Eddy Simulations (DES) or Large Eddy Simulations (LES) with a focus on gas-phase mixing and combustion. Also of interest are methods for handling detailed finite-step chemical kinetics in the context of large-scale computations such as flamelet libraries and/or in-situ adaptive tabulation (ISAT) of finite-rate kinetics. Development of new promising approaches, as well as the enhancement of existing methods, are appropriate with an emphasis being given to fundamental physics-based models. Underlying model assumptions such as incompressibility should be evaluated for consistency for the intended combustion regimes. Model predictions must be validated against relevant data, including those being obtained within related AFOSR programs. A further requirement is that the model development be made modular by the specification of standardized Application Programming Interfaces (or API"s), which would enable the models to be available as plug-in libraries to appropriate turbulent reacting flow codes of relevance for Air Force applications. These interfaces should be fashioned to be independent of code-specific data structures in order to maintain generality. The availability of standard LES or DES sub-grid models and finite-rate chemical kinetics can be assumed to exist in the parent code, but all other aspects of the turbulent combustion models would be enabled through the new module or modules. PHASE I: Demonstrate turbulent combustion model capability that shows promise in the context of DES and LES calculations. Evaluate model assumptions for consistency for the intended combustion regimes. Develop prototype modules with well-characterized and generalized interfaces. PHASE II: Further develop/enhance the target turbulent combustion model capability. Perform detailed validation for test cases of relevance to the Air Force. Demonstrate the modular approach for the turbulent combustion sub-models in candidate turbulent reacting flow code or codes of relevance to the DoD. PHASE III: Turbulent combustion phenomena are of key relevance to the performance of military propulsion systems, including liquid rockets, solid rockets, gas turbines, and augmentors, and to non-military systems such as space launch systems, aircraft engines, land-based power systems, and automotive engines. REFERENCES: 1. N. Peters, Turbulent Combustion, Cambridge University Press, (2000). 2. T. Poinsot and D. Veynante, Theoretical and Numerical Combustion, 2nd ed., R.T. Edwards (2005). 3. Kerstein, A., A Linear Eddy Model of Turbulent Scalar Transport and Mixing, Combustion Science and Technology, Vol. 60, pp. 391. 4. L. Lu, S. R, Lantz, Z. Ren, S. B. Pope, Computational Efficient Implementation of Combustion Chemistry in Parallel PDF Calculations, Journal of Computational Physics, Vol. 228, Issue 15, pp. 5490-5525 (2009). 5. B. Franzelli, E. Riber, L.Y.M. Gicquel, and T. Poinsot, Large Eddy Simulation of combustion instabilities in a lean partially premixed swirled flame. Combustion and Flame, 159(2):621 - 637, 2012.
AF13-AT13: Broad Band, High Efficiency Solar Cells
Description: OBJECTIVE: Demonstrate a high-efficiency solar cell with a photovoltaic efficiency comparable to that of present day multi-junction solar cells but with a spectral response extending into the IR, suitable for autonomous vehicle or space platform applications. DESCRIPTION: Solar cell technology represents a key power management component in a variety of terrestrial and space based Air Force systems. Improvements in solar cell efficiency, as well as the ability to harvest solar energy over a broader wavelength range represents a means to significantly improve mission lifetime and effectiveness while still adhering to strict size and weight requirements. Recent advances in the development of nanomaterials with tunable intermediate bands and enhanced multi-exciton generation, as well as achievements in nanophotonics, hold significant promise for dramatic improvements in the photovoltaic efficiency of next generation solar cells [1,2]. Modern nanomaterials offer the possibility of improving the harvesting of solar radiation by including the IR region of the solar spectrum, as well as the ability to manage photoelectron kinetics for more effective photovoltaic conversion. In practice, however, the actual demonstration of a nanomaterial-based solar cell with conversion efficiency comparable to that of a state-of-the-art multi-junction solar cell, (30%-40%), has yet to be demonstrated. The intent of this solicitation is to prove, that through the integration of the theoretical and experimental aspects of nanomaterial research, nanophotonics, and photovoltaics, an efficient, broad band (all-weather), lightweight, reliable solar cell can result with performance characteristics exceeding that of present day multi-junction solar cells. By implicitly incorporating energy harvesting from the IR region of the solar spectrum, a low-visible light, all weather capability will result significantly impacting autonomous vehicle effectiveness and dramatically improving space platform power management efficiency. The photovoltaic device proposed is expected to incorporate the developing nanomaterials and advanced nanophotonic and photovoltaic technologies. The intent of this integration is to significantly increase the wavelength range over which energy harvesting occurs, increase the overall photovoltaic conversion efficiency and to reduce the both the thermal and recombination losses for improved photovoltaic conversion efficiency while still maintaining acceptable photovoltaic circuit characteristics. The resulting device will represent a significant advancement in next generation single-junction solar cell technology in terms of size, weight and conversion efficiency. By achieving efficiencies comparable to multi-junction technologies in a single-junction format a relatively inexpensive solar cell will result when compared to existing high-efficiency, energy harvesting components. PHASE I: Develop a solar cell device incorporating novel nanomaterials and advanced photovoltaic technologies. These efforts should include modeling, experimental demonstrations, and a detailed evaluation of the performance. The Phase I device should demonstrate at least 25% photovoltaic efficiency at AM 1.5 with a clear path towards improvements needed to reach the Phase II performance characteristics. PHASE II: Demonstrate a light-weight photovoltaic device with at least 30% efficiency at AM 1.5. Demonstrate all-weather operation due to effective harvesting and conversion of IR radiation. Propose a manufacturing scheme for the large, wafer scale, production of the device and address manufacturing costs compared to other multi-junction solar cell technologies in terms of cost per kg. PHASE III: Terrestrial and space based energy harvesting for remote and autonomous vehicles. Energy harvesting, power production, photovoltaics. REFERENCES: 1. A. Luque and A. Marti,"Increasing the Efficiency of Ideal Solar Cells by Photon Induced Transitions at Intermediate Levels"Phys. Rev. Lett., 78, 5014 (1997). 2. K. A. Sablon, J. W. Little,V. Mitin, A. Sergeev, N. Vagidov, and K. Reinhardt,"Strong Enhancement of Solar Cell Efficiency Due to Quantum Dots with Built-In Charge", Nano Letters, 11, 2311 (2011).
AF13-AT14: Automated assessment of disclosure risk
Description: OBJECTIVE: Develop algorithms to automatically categorize and quantify the security risks from disclosure of information. DESCRIPTION: Information that is released from a security domain, either intentionally as part of approved information sharing, or through malicious or accidental covert channels, can cause harm by revealing secrets. In practice, efforts to control such leaks in information processing systems are costly in terms of additional human effort and often impair the usability and timeliness of information sharing. For this reason, it is important to accurately assess the risk associated with different types of information, so that effort is focused on the most damaging leaks. For some types of information, such as passwords or encryption keys, the consequences of leaking even a few bits of information can be very severe. The goal of this effort is to develop automated support for reasoning about the risks associated with information disclosure. Using tools such as information theory, the theory of knowledge, and probability, the researchers will develop principled methods by which the degree of exposure, due to such a release, can be assessed. This research will produce a taxonomy of information disclosure risks, and a model of risk within a subset of the identified categories. The model should address the problem of disclosure through logical and/or statistical inference, and should take into account the contextual information that enables inference. The researchers should provide a practical approach for identifying such contextual information and should demonstrate how to factor in the knowledge that is probably already available to potential adversaries. The result of this research will be the development of algorithms and methods for categorizing information and for automatically estimating the risk that information will fall into a subset of the identified categories. The researchers shall use the methods to develop practical tools that can compute disclosure risk for a given piece of information and a large number of given secrets. The researchers shall address the problem of cumulative risk due to disclosure in a sequence of releases or compromises. Possible military and government applications of this technology include: (1) Assessment of disclosure risk for"data at rest", (2) quantitative assessment of the degree of compromise for one secret caused by release of related information, (3) quantitative estimates of the effectiveness of security counter-measures (such as disinformation, or the introduction of"decoy"informationinformation that appears to be sensitive, but is actually not). PHASE I: Survey existing research on quantitative measures of risk due to information disclosure. Develop a taxonomy of categories of information disclosure. Develop a model of information disclosure for categories, and quantitative measures of disclosure risk. Design methods for automatic categorizing information according to the type of risk, and algorithms for automatically computing quantitative risk. PHASE II: Use the algorithms and methods developed in Phase I as the basis for a prototype tool to automatically assess disclosure risk. Develop scenarios for information disclosure, and find or create realistic data for use with these scenarios. Demonstrate the developed tools using the scenario data. Create a detailed report showing the effectiveness of the tools in the context of the scenarios. PHASE III: Secure computer systems, cross-domain information sharing. Controlled disclosure of proprietary corporate information, privacy of individual health or financial information, protection of intellectual property. REFERENCES: 1."Deciding knowledge in security protocols under equational theories"Martin Abadi and Veronique Cortier, INRIA, 2."Knowledge management: securing the future"Ebrahim Randeree, Journal of Knowledge Management, Vol. 10, No. 4, 2006, pp. 145-156. 3."Assessing Disclosure Risk in Anonymized Datasets"Alexei Kounine and Michele Bezzi, 4."Data-Centric Quantitative Computer Security Risk Assessment"Brett Berger, SANS Institute, 2003,
AF13-AT15: Precision high-frequency pressure measurements in ground and flight test
Description: OBJECTIVE: Enable precision measurement of high-frequency acoustic waves in ground and flight test experiment. DESCRIPTION: Advancements in the fields of high-fidelity, massively parallel computing and laser-based diagnostics have provided revolutionary new capabilities enabling detailed insight into the dynamic microscale phenomena that drive the macroscopic behavior of high-speed flows. A notable achievement in this area is the advancement of boundary layer transition estimation methods that provide increasingly accurate estimations of the growth of flowfield instabilities that drive the transition process. Although sophisticated diagnostic methods are capable of detecting and measuring the growth of instabilities that drive transition, assessment and validation of transition estimation methods applied to complex ground test configurations and in flight research requires the efficient, precise, simultaneous measurement of high-frequency pressure fluctuations at a relatively large number of locations on the surface of the test body. This topic seeks to develop innovative new pressure measurement methods capable of measuring high frequency acoustic disturbances within a high-speed boundary layer, yet economically and efficiently utilized in complex ground and flight research configurations. An idealized version of such an instrument would be capable of resolving fluctuation amplitudes on the order of 0.01psia or smaller (0.002psia) and instability frequencies up to 1MHz while operating at temperatures up to 1250 deg. F. The sensor should be capable of maintaining calibration throughout the duration of a ground test campaign and yield quantitative amplitude measurements with uncertainties of 0.5% or less (0.1%). The instrument should be deployable in a manner comparable to conventional pressure measurement transducers and not require special handling during installation. The surface area of the sensor should be less than 2mm in diameter. Finally, the cost per unit if full commercial production is achieved should be less than $2000 per sensor or measurement location. It is understood that successful responses to this topic will not be able to meet the entire list of desirable attributes listed above, but responses are encouraged to attempt to meet as many of the attributes as possible while providing a compelling justification for essential trade-offs in the proposal. Current measurements of the second-mode wave instability are being made as described in references below. This topic seeks innovative improvements in the calibration, sensitivity and size of this current capability. PHASE I: Demonstrate a proof-of-concept version of the instrument within a supersonic boundary layer. Meet proposed frequency and sensitivity objectives. PHASE II: Measure high-frequency acoustic waves within a hypersonic flowfield Mach>6 with a boundary layer edge Mach number greater than 4. Meet proposed objectives for sensitivity, sensor size and operating temperature. PHASE III: Fully demonstrate the entire diagnostic system within an Air Force sponsored ground or flight research campaign at Mach numbers greater than 8. REFERENCES: 1. Shann Rufer, Dennis Berridge,"Experimental Study of Second-Mode Instabilities on a 7-Degree Cone at Mach 6", Paper AIAA-2011-3877, June, 2011. 2. Dennis Berridge, Katya Casper, Shann Rufer, Christopher Alba, Daniel Lewis, Steven Beresh, Steven Schneider."Measurements and Computations of Second-Mode Instability Waves in Several Hypersonic Wind Tunnels,"AIAA-2010-5002, June, 2010. 3. Katya M. Casper, Steven J. Beresh, and Steven P. Schneider. Pressure fluctuations beneath turbulent spots and instability wave packets in a hypersonic boundary layer. Paper 2011-0372, AIAA, January 2011. 4. Katya M. Casper, Steven J. Beresh, and Steven P. Schneider. Spanwise growth of the turbulent spot pressure fluctuation field in a hypersonic boundary layer. Paper 2011- 3873, AIAA, June 2011. 5. Kimmel, R. L., Adamczak, D., and Brisbane DSTO-AVD Team,"HIFiRE-1 Preliminary Aerothermodynamic Experiments,"AIAA paper 2011-3414, June 2011. 6. Hofferth JW, Saric WS. Boundary-layer Transition on a Flared Cone in the Texas A & M Mach 6 Quiet Tunnel. AIAA Paper 2012-0923.