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Air Force Institute of Technology

2011

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Articles 1 - 30 of 187

Full-Text Articles in Engineering

Exploitation Of Unintentional Information Leakage From Integrated Circuits, William E. Cobb Dec 2011

Exploitation Of Unintentional Information Leakage From Integrated Circuits, William E. Cobb

Theses and Dissertations

Unintentional electromagnetic emissions are used to recognize or verify the identity of a unique integrated circuit (IC) based on fabrication process-induced variations in a manner analogous to biometric human identification. The effectiveness of the technique is demonstrated through an extensive empirical study, with results presented indicating correct device identification success rates of greater than 99:5%, and average verification equal error rates (EERs) of less than 0:05% for 40 near-identical devices. The proposed approach is suitable for security applications involving commodity commercial ICs, with substantial cost and scalability advantages over existing approaches. A systematic leakage mapping methodology is also proposed to …


Link Performance Analysis For A Proposed Future Architecture Of The Air Force Satellite Control Network, Eric W. Nelson Dec 2011

Link Performance Analysis For A Proposed Future Architecture Of The Air Force Satellite Control Network, Eric W. Nelson

Theses and Dissertations

The Air Force Satellite Control Network (AFSCN) is a worldwide network of ground stations that support a wide variety of users from the National Aeronautics and Space Administration (NASA) to the National Reconnaissance Office (NRO). The network performs tracking, telemetry, and commanding (TT&C) for these varied users. Users, located at Satellite Operations Centers (SOC), must compete for time on the AFSCN. This thesis demonstrates how to predict satellite link performance, specifically by users of the AFSCN. It will also demonstrate how users might use this capability to save spacecraft power. A tool was created called the AFSCN Link Predictor (LP) …


Rapid Development: A Content Analysis Comparison Of Literature And Purposive Sampling Of Afrl Rapid Reaction Projects, Andrew R. Smith Dec 2011

Rapid Development: A Content Analysis Comparison Of Literature And Purposive Sampling Of Afrl Rapid Reaction Projects, Andrew R. Smith

Theses and Dissertations

In the current environment of military operations requesting faster delivery schedules to counter insurgent tactics, the engineering team often searches for how to quickly deliver the 80% solution, typically in 6-12 months. These are labeled rapid development projects. A content analysis of best practices in commercial product development literature, where time to market is often a driving factor, was accomplished showing varying emphasis of systems engineering technical and technical management processes. Technical Planning, Stakeholders Requirements Development, and Architecture Design were identified as important processes. This analysis confirms preconceived notions of plan upfront and early by emphasizing the SE processes of …


Electroluminescence Studies On Longwavelength Indium Arsenide Quantum Dot Microcavities Grown On Gallium Arsenide, John C. Ramsey Dec 2011

Electroluminescence Studies On Longwavelength Indium Arsenide Quantum Dot Microcavities Grown On Gallium Arsenide, John C. Ramsey

Theses and Dissertations

A comprehensive study of the electroluminescence of four GaAs/AlGaAs microcavity devices with InAs/GaInAs quantum dot active regions emitting near 1.3 µm was conducted. The four molecular beam epitaxial grown samples with AlAs oxide aperture confinement layers were fabricated, characterized, and optically modeled. Optical power transmission of the samples was modeled using Matlab and compared with measured transmission data. Resonant cavity light emitting diodes (RCLEDs) and three vertical cavity surface emitting laser (VCSEL) samples were fabricated and electro-optically characterized over a range of injection currents and temperatures. Devices achieved continuous wave room temperature lasing at 1.28 µm with an output power …


Linear-Quadratic Control Of A Mems Micromirror Using Kalman Filtering, Jamie P. Schnapp Dec 2011

Linear-Quadratic Control Of A Mems Micromirror Using Kalman Filtering, Jamie P. Schnapp

Theses and Dissertations

The deflection limitations of electrostatic flexure-beam actuators are well known. Specifically, as the beam is actuated and the gap traversed, the restoring force necessary for equilibrium increases proportionally with the displacement to first order, while the electrostatic actuating force increases with the inverse square of the gap. Equilibrium, and thus stable open-loop voltage control, ceases at one-third the total gap distance, leading to actuator snap-in. A Kalman Filter is designed with an appropriately complex state dynamics model to accurately estimate actuator deflection given voltage input and capacitance measurements, which are then used by a Linear Quadratic controller to generate a …


A Method For Measuring Programmatic Dependency And Interdependency Between Dod Acquisition Programs, Matthew B. Christensen Dec 2011

A Method For Measuring Programmatic Dependency And Interdependency Between Dod Acquisition Programs, Matthew B. Christensen

Theses and Dissertations

There is currently no accepted method for quantitative measurement of acquisition program interdependency. While some methods exist for measuring dependency or interdependency at the component or system level, these methods do not translate well to program interdependency measurement. The objective of this thesis is to provide a model for measuring acquisition program interdependency accurately and quantitatively. The model presented in this thesis uses four Interdependency Factors to identify dependency relationships between programs. Specific Interdependency Levels are then used to measure the strengths of those dependencies. The model also accounts for measurement of dependencies upon programs that are not directly connected, …


Investigation Of Gallium Nitride Transistor Reliability Through Accelerated Life Testing And Modeling, Bradley D. Christiansen Dec 2011

Investigation Of Gallium Nitride Transistor Reliability Through Accelerated Life Testing And Modeling, Bradley D. Christiansen

Theses and Dissertations

Gallium nitride high electron mobility transistors are attractive to the DoD for their ability to operate at high frequencies, voltages, temperatures, and power. Yet, there are concerns about the reliability of these devices. Various degradation mechanisms and their causes are proposed in the literature. A variety of reliability tests were conducted to understand these mechanisms and causes. A multi-stressor experiment revealed different failure mechanisms than are in the literature. In particular, the devices tested at high voltage in the OFF state did not degrade significantly as suggested by others' reports. The validity of temperature-accelerated life testing when applied to GaN …


Development Of Photographic Dynamic Measurements Applicable To Evaluation Of Flapping Wing Micro Air Vehicles, Jeremy C. Murray Dec 2011

Development Of Photographic Dynamic Measurements Applicable To Evaluation Of Flapping Wing Micro Air Vehicles, Jeremy C. Murray

Theses and Dissertations

Developments in the area of flapping wing micro air vehicles (FWMAVs) of a small size and with limited range. This has lead to a great deal of interest in biomimetric designs based on flapping wing flyers, including the North American Hawkmoth (Manduca Sexta). By utilizing high speed photography and photogrammetry the dynamic flapping of the wing can be characterized for comparison with mathematical models, namely computational fluid dynamics (CFD) and finite element analysis (FEA).To successfully utilize high speed image capture, a method of successfully digitizing many data points in a short period of time needs to be developed. The effort …


The Use Of Various Failure Criteria As Applied To High Speed Wear, David A. Huber Dec 2011

The Use Of Various Failure Criteria As Applied To High Speed Wear, David A. Huber

Theses and Dissertations

This research has been aimed at developing methods to predict mechanical wear of sliding bodies at high velocities. Specifically, wear of test sled slippers at the Holloman High Speed Test Track at Holloman AFB, NM, is being considered. Developing a numerical model to represent the velocity range achieved at the test track is infeasible, so numerical modeling techniques must be adopted. Previous research has made use of finite element codes to simulate the high velocity sliding event. However, the extreme velocities at the test track can create numerical errors in the finite element codes. To avoid the numerical errors, an …


Scramjet Isolator Modeling And Control, John R. Hutzel Dec 2011

Scramjet Isolator Modeling And Control, John R. Hutzel

Theses and Dissertations

The scramjet isolator is a duct in which pressure increases from the inlet to the combustor via a shock train. The shock train leading edge (LE) location must be controlled in an operational scramjet. A LE location measurement algorithm, dynamic model, and control algorithm were developed and validated with 500 frame per second (FPS) shadowgraph images in this research. The test apparatus consisted of a direct connect cold-flow high-speed wind tunnel with an adjustable ramp mounted in the tunnel floor. Ramp adjustments changed the tunnel cross-sectional area which changed the tunnel back pressure and LE location. Wall-mounted pressure transducers and …


Coupled Radiation-Gasdynamic Solution Method For Hypersonic Shock Layers In Thermochemical Nonequilibrium, Christopher L. Martin Jr. Dec 2011

Coupled Radiation-Gasdynamic Solution Method For Hypersonic Shock Layers In Thermochemical Nonequilibrium, Christopher L. Martin Jr.

Theses and Dissertations

The purpose of this research was to develop a highly accurate computational method for calculating the nonequilibrium radiative heat transfer within reentry shock layers. The nonequilibrium state of the flowfield was solved using the multispecies multitemperature nonequilibrium flow solver NH7AIR which is capable of separately tracking the vibrational energy of each diatomic species and the energy of the free electrons. The calculation of radiative heat transfer was performed by utilizing the detailed line-by-line spectral radiation solver SPRADIAN. Two radiative transport schemes were implemented in this coupled code. The first scheme was the standard tangent slab solution method. The second scheme …


Navigation And Position Determination With A Multicarrier Modulation Signal Of Opportunity, Richard K. Martin, Jamie S. Velotta, John F. Raquet Dec 2011

Navigation And Position Determination With A Multicarrier Modulation Signal Of Opportunity, Richard K. Martin, Jamie S. Velotta, John F. Raquet

AFIT Patents

A multicarrier modulation position determination method that includes deploying at least one known receiver with a known location and a second receiver with an unknown location. At least two signals of opportunity with different locations are obtained by both the receiver and the second receiver. The signals having a plurality of block data, the block data having block boundaries. The block boundaries including a beginning block boundary and an end block boundary. The block data further including a cyclic prefix at the beginning block boundary. Acquiring a plurality of data samples for at least a portion of the block data …


Optimized Hyperspectral Imagery Anomaly Detection Through Robust Parameter Design, Francis M. Mindrup Oct 2011

Optimized Hyperspectral Imagery Anomaly Detection Through Robust Parameter Design, Francis M. Mindrup

Theses and Dissertations

Anomaly detection algorithms for hyperspectral imagery (HSI) are an important first step in the analysis chain which can reduce the overall amount of data to be processed. The actual amount of data reduced depends greatly on the accuracy of the anomaly detection algorithm implemented. Most, if not all, anomaly detection algorithms require a user to identify some initial parameters. These parameters (or controls) affect overall algorithm performance. Regardless of the anomaly detector being utilized, algorithm performance is often negatively impacted by uncontrollable noise factors which introduce additional variance into the process. In the case of HSI, the noise variables are …


Modeling And Analysis Of High Energy Laser Weapon System Performance In Varying Atmospheric Conditions, Megan P. Melin Sep 2011

Modeling And Analysis Of High Energy Laser Weapon System Performance In Varying Atmospheric Conditions, Megan P. Melin

Theses and Dissertations

This thesis addresses two primary concerns relating to Directed Energy (DE) models and tests: need for more use of Design of Experiment (DOE) in structuring DE models and tests, and lack of modeling atmospheric variability in High Energy Laser (HEL) weapon system propagation models and tests. To address these concerns we use a DOE factorial design to capture main, interaction, and non-linear effects between modeled weapon design and environmental factors in a well defined simulated Air-to-Ground HEL engagement scenario. The scenario modeled considers a B1-B aircraft in the 2022 timeframe equipped with an HEL weapon, irradiating a ground target from …


A Novel Malware Target Recognition Architecture For Enhanced Cyberspace Situation Awareness, Thomas E. Dube Sep 2011

A Novel Malware Target Recognition Architecture For Enhanced Cyberspace Situation Awareness, Thomas E. Dube

Theses and Dissertations

The rapid transition of critical business processes to computer networks potentially exposes organizations to digital theft or corruption by advanced competitors. One tool used for these tasks is malware, because it circumvents legitimate authentication mechanisms. Malware is an epidemic problem for organizations of all types. This research proposes and evaluates a novel Malware Target Recognition (MaTR) architecture for malware detection and identification of propagation methods and payloads to enhance situation awareness in tactical scenarios using non-instruction-based, static heuristic features. MaTR achieves a 99.92% detection accuracy on known malware with false positive and false negative rates of 8.73e-4 and 8.03e-4 respectively. …


Design And Control Of Flapping Wing Micro Air Vehicles, Michael L. Anderson Sep 2011

Design And Control Of Flapping Wing Micro Air Vehicles, Michael L. Anderson

Theses and Dissertations

Flapping wing Micro Air Vehicles (MAVs) continues to be a growing field, with ongoing research into unsteady, low Re aerodynamics, micro-fabrication, and fluid-structure interaction. However, research into flapping wing control of such MAVs continues to lag. Existing research uniformly consists of proposed control laws that are validated by computer simulations of quasi-steady blade-element formulae. Such simulations use numerous assumptions and cannot be trusted to fully describe the flow physics. Instead, such control laws must be validated on hardware. Here, a novel control technique is proposed called Bi-harmonic Amplitude and Bias Modulation (BABM) which can generate forces and moments in 5 …


Stochastic Real-Time Optimal Control: A Pseudospectral Approach For Bearing-Only Trajectory Optimization, Steven M. Ross Sep 2011

Stochastic Real-Time Optimal Control: A Pseudospectral Approach For Bearing-Only Trajectory Optimization, Steven M. Ross

Theses and Dissertations

A method is presented to couple and solve the optimal control and the optimal estimation problems simultaneously, allowing systems with bearing-only sensors to maneuver to obtain observability for relative navigation without unnecessarily detracting from a primary mission. A fundamentally new approach to trajectory optimization and the dual control problem is developed, constraining polynomial approximations of the Fisher Information Matrix to provide an information gradient and allow prescription of the level of future estimation certainty required for mission accomplishment. Disturbances, modeling deficiencies, and corrupted measurements are addressed with recursive updating of the target estimate with an Unscented Kalman Filter and the …


Increasing The Performance Of A Sliding Discharge Actuator Through The Application Of Multiple Potentials, Steven D. Seney Jr. Sep 2011

Increasing The Performance Of A Sliding Discharge Actuator Through The Application Of Multiple Potentials, Steven D. Seney Jr.

Theses and Dissertations

This work encompasses a comparison between a sliding discharge DBD actuator with grounded and AC biased sliding electrode driven at kHz frequency. The induced velocity in the bulk flow was recorded with PIV and compared for multiple potential splits between two test configurations and a baseline sliding discharge actuator over three test phases. In the first test phase, varying potential splits were examined between the primary and secondary electrode with the sliding electrode grounded. The potential splits induced a thicker induced jet than the baseline case with similar peak velocities on the order of 1.25 m/s at the 61 mm …


Twitter Malware Collection System: An Automated Url Extraction And Examination Platform, Benjamin B. Kuhar Sep 2011

Twitter Malware Collection System: An Automated Url Extraction And Examination Platform, Benjamin B. Kuhar

Theses and Dissertations

As the world becomes more interconnected through various technological services and methods, the threat of malware is increasingly looming overhead. One avenue in particular that is examined in this research is the social networking service Twitter. This research develops the Twitter Malware Collection System (TMCS). This system gathers Uniform Resource Locators (URLs) posted on Twitter and scans them to determine if any are hosting malware. This scanning process is performed by a cluster of Virtual Machines (VMs) running a specified software configuration and the execution prevention system known as ESCAPE, which detects malicious code. When a URL is detected by …


Two-Dimensional, Time-Dependent Plasma Structures Of A Hall Effect Thruster, David Liu Sep 2011

Two-Dimensional, Time-Dependent Plasma Structures Of A Hall Effect Thruster, David Liu

Theses and Dissertations

The Hall thruster is a type of electric propulsion utilized by satellites to perform a wide variety of missions ranging from station keeping, orbital maneuvers, and even deep space propulsion. In order to accommodate the multitude of missions it also has a wide assortment of sizes and power configurations which can range from approximately an inch in diameter at 20 W to a couple of feet in diameter at 1.5 kW. Additionally, this electro-static device provides high specific impulse without the added weight penalty associated with conventional chemical thrusters. It supplies this high specific impulse by ionizing a gas such …


Identification And Classification Of Player Types In Massive Multiplayer Online Games Using Avatar Behavior, Earl M. Bednar Sep 2011

Identification And Classification Of Player Types In Massive Multiplayer Online Games Using Avatar Behavior, Earl M. Bednar

Theses and Dissertations

The purpose of our research is to develop an improved methodology for classifying players (identifying deviant players such as terrorists) through multivariate analysis of data from avatar characteristics and behaviors in massive multiplayer online games (MMOGs). To build our classification models, we developed three significant enhancements to the standard Generalized Regression Neural Networks (GRNN) modeling method. The first enhancement is a feature selection technique based on GRNNs, allowing us to tailor our feature set to be best modeled by GRNNs. The second enhancement is a hybrid GRNN which allows each feature to be modeled by a GRNN tailored to its …


Integrated Approach To Free Space Optical Communications In Strong Turbulence, Jason A. Tellez Sep 2011

Integrated Approach To Free Space Optical Communications In Strong Turbulence, Jason A. Tellez

Theses and Dissertations

The propagation of a free space optical communication signal through atmospheric turbulence experiences random fluctuations in intensity, including signal fades which negatively impact the communications link performance. This research develops an analytical probability density function (PDF) to model the best case scenario of using multiple independent beams to reduce the intensity fluctuations. The PDF was further developed to account for partially correlated beams, such as would be experienced by beams having finite separation. The PDF was validated with results obtained from digital simulations as well as lab experiments. The research showed that as the number of transmitted beams increases the …


Major Cost Drivers Of Motor Vehicle Crashes Involving Air Force Military Personnel And The Influence Of The Military Environment, Ilias Kesisiklis Sep 2011

Major Cost Drivers Of Motor Vehicle Crashes Involving Air Force Military Personnel And The Influence Of The Military Environment, Ilias Kesisiklis

Theses and Dissertations

Motor vehicle crashes (MVCs) involving USAF military personnel when off duty/off base are a critical concern for the Department of Defense (DoD), due to potential impact on mission readiness. In addition, the cost of MVCs places excessive financial burden on the USAF budget, apart from productivity loss and negative emotional consequences on the victims. In particular, total injury cost was $ 356M, based on 2010 CY dollars. Determining the underlying factors leading to MVCs is crucial to establishing effective preventive measures to mitigate the negative consequences of MVCs.
This thesis applied categorical data and multiple regression analyses on (AFSC) historical …


Evaluation Of Nanocomposites For Shielding Electromagnetic Interference, Kenneth Y. Chong Sep 2011

Evaluation Of Nanocomposites For Shielding Electromagnetic Interference, Kenneth Y. Chong

Theses and Dissertations

Numerous efforts are ongoing to research and develop nanocomposite materials for space applications. Current composite spacecraft materials are nonconductive and require costly shielding materials to be applied in order to protect spacecraft from the harmful effects caused by electromagnetic interference (EMI), which is a by-product of exposure to the space environment. Conductive fillers (nanofibers) are being employed in composites to produce nanocomposites to reduce the dry weight of space vehicles while providing sufficient protection against EMI. This eliminates the need to apply secondary shielding materials to spacecraft. This thesis studied a nanocomposite consisting of Cycom 5575-2 glass with multi-walled carbon …


Distributed Spacing Stochastic Feature Selection And Its Application To Textile Classification, Jeffrey D. Clark Sep 2011

Distributed Spacing Stochastic Feature Selection And Its Application To Textile Classification, Jeffrey D. Clark

Theses and Dissertations

Many situations require the need to quickly and accurately locate dismounted individuals in a variety of environments. In conjunction with other dismount detection techniques, being able to detect and classify clothing (textiles) provides a more comprehensive and complete dismount characterization capability. Because textile classification depends on distinguishing between different material types, hyperspectral data, which consists of several hundred spectral channels sampled from a continuous electromagnetic spectrum, is used as a data source. However, a hyperspectral image generates vast amounts of information and can be computationally intractable to analyze. A primary means to reduce the computational complexity is to use feature …


Using Reputation Based Trust To Overcome Malfunctions And Malicious Failures In Electric Power Protection Systems, Jose E. Fadul Sep 2011

Using Reputation Based Trust To Overcome Malfunctions And Malicious Failures In Electric Power Protection Systems, Jose E. Fadul

Theses and Dissertations

This dissertation advocates the use of reputation-based trust in conjunction with a trust management framework based on network flow techniques to form a trust management toolkit (TMT) for the defense of future Smart Grid enabled electric power grid from both malicious and non-malicious malfunctions. Increases in energy demand have prompted the implementation of Smart Grid technologies within the power grid. Smart Grid technologies enable Internet based communication capabilities within the power grid, but also increase the grid's vulnerability to cyber attacks. The benefits of TMT augmented electric power protection systems include: improved response times, added resilience to malicious and non-malicious …


Critical Information Technology On Fpgas Through Unique Device Specific Keys, Miles E. Mcgee Sep 2011

Critical Information Technology On Fpgas Through Unique Device Specific Keys, Miles E. Mcgee

Theses and Dissertations

Field Programmable Gate Arrays (FPGAs) are being used for military and other sensitive applications, the threat of an adversary attacking these devices is an ever present danger. While having the ability to be reconfigured is helpful for development, it also poses the risk of its hardware design being cloned. Static random access memory (SRAM) FPGA's are the most common type of FPGA used in industry. Every time an SRAM-FPGA is powered up, its configuration must be downloaded. If an adversary is able to obtain that configuration, they can clone sensitive designs to other FPGAs. A technique that can be used …


Hyperspectral-Based Adaptive Matched Filter Detector Error As A Function Of Atmospheric Profile Estimation, Allan W. Yarbrough Sep 2011

Hyperspectral-Based Adaptive Matched Filter Detector Error As A Function Of Atmospheric Profile Estimation, Allan W. Yarbrough

Theses and Dissertations

Hyperspectral imagery is collected as radiance data. This data is a function of multiple variables: the radiation profile of the light source, the reflectance of the target, and the absorption and scattering profile of the medium through which the radiation travels as it reflects off the target and reaches the imager. Accurate target detection requires that the collected image matches as closely as possible the known "true" target in the classification database. Therefore, the effect of the radiation source and the atmosphere must be removed before detection is attempted. While the spectrum of solar light is relatively stable, the effect …


Extracting Forensic Artifacts From Windows O/S Memory, James S. Okolica, Gilbert L. Peterson Aug 2011

Extracting Forensic Artifacts From Windows O/S Memory, James S. Okolica, Gilbert L. Peterson

AFIT Documents

Memory analysis is a rapidly growing area in both digital forensics and cyber situational awareness (SA). Memory provides the most accurate snapshot of what is occurring on a computer at a moment in time. By combining it with event and network logs as well as the files present on the filesystem, an analyst can re-create much of what has occurred and is occuring on a computer. The Compiled Memory Analysis Tool (CMAT) takes either a disk image of memory from a Windows operating system or an interface into a virtual machine running a Windows operating system and extracts forensic artifacts …


A Taskable Space Vehicle: Realizing Cost Savings By Combining Orbital And Suborbital Flight, Thomas Co, Jonathan T. Black Jul 2011

A Taskable Space Vehicle: Realizing Cost Savings By Combining Orbital And Suborbital Flight, Thomas Co, Jonathan T. Black

Faculty Publications

The use of space gives the United States distinct advantages in any battlefield environment, but the high cost of space operations increasingly jeopardizes those advantages. Although the United States pioneered much of the current space technology, declining budgets for space research, development, and operations leave our legacy systems vulnerable to adversaries around the world. Other nations formerly incapable of space exploitation are quickly learning to counter US space technologies at surprisingly low costs. In order to reduce the expense of deploying and maintaining a robust space capability, the Department of Defense (DOD) must change the status quo in space operations …