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Air Force Institute of Technology

Theses and Dissertations

2014

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Articles 1 - 30 of 56

Full-Text Articles in Engineering

Characterizing And Managing Intrusion Detection System (Ids) Alerts With Multi-Server/Multi-Priority Queuing Theory, Christopher C. Olsen Dec 2014

Characterizing And Managing Intrusion Detection System (Ids) Alerts With Multi-Server/Multi-Priority Queuing Theory, Christopher C. Olsen

Theses and Dissertations

The DoD sets forth an objective to employ an active cyber defense capability to prevent intrusions onto DoD networks and systems. Intrusion Detection Systems (IDS) are a critical part of network defense architectures, but their alerts can be difficult to manage. This research applies Queuing Theory to the management of IDS alerts, seeking to answer how analysts and priority schemes effect alert processing performance. To characterize the effect of these two variables on queue wait times, a MATLAB simulation was developed to allow parametric analysis under two scenarios. The first varies the number of analysts and the second varies the …


Exploring Individual Differences In Workload Assessment, Danielle K. Boeke Dec 2014

Exploring Individual Differences In Workload Assessment, Danielle K. Boeke

Theses and Dissertations

Air Force missions continue to increase in complexity often imposing higher levels of task load from cognitive tasks on the operators. This increased task load manifests itself in increased cognitive workload and potentially derogated performance. While cognitive workload has been studied for decades, recent advances in objective workload models and physiology monitoring have the potential to provide a more robust understanding of workload, potentially allowing systems to adaptively employ automation to maintain operator peak performance. The current research sought to provide insight into the relationship between subjective workload, task performance, objective workload, and select physiology measures. Analysis of an existing …


Terrain Referenced Navigation Using Sift Features In Lidar Range-Based Data, Matthew T. Leines Dec 2014

Terrain Referenced Navigation Using Sift Features In Lidar Range-Based Data, Matthew T. Leines

Theses and Dissertations

The use of GNSS in aiding navigation has become widespread in aircraft. The long term accuracy of INS are enhanced by frequent updates of the highly precise position estimations GNSS provide. Unfortunately, operational environments exist where constant signal or the requisite number of satellites are unavailable, significantly degraded, or intentionally denied. This thesis describes a novel algorithm that uses scanning LiDAR range data, computer vision features, and a reference database to generate aircraft position estimations to update drifting INS estimates. The algorithm uses a single calibrated scanning LiDAR to sample the range and angle to the ground as an aircraft …


Multi-Objective Trajectory Optimization Of A Hypersonic Reconnaissance Vehicle With Temperature Constraints, Tadeusz J. Masternak Dec 2014

Multi-Objective Trajectory Optimization Of A Hypersonic Reconnaissance Vehicle With Temperature Constraints, Tadeusz J. Masternak

Theses and Dissertations

Temperature-constrained optimal trajectories for a scramjet-based hypersonic reconnaissance vehicle were generated by developing an optimal control formulation and solving it using a variable order Gauss-Radau quadrature collocation method. The vehicle was assumed to be an air-breathing reconnaissance aircraft that has specified takeoff/landing locations, airborne refueling constraints, specified no-fly zones, and specified targets for sensor data collections. The aircraft model included fight dynamics, aerodynamics, and thermal constraints. This model was incorporated into an optimal control formulation that includes constraints on both the vehicle as well as mission parameters, such as avoidance of no-fly zones and coverage of high-value targets. Optimal trajectories …


Hot Streak Characterization In Serpentine Exhaust Nozzles, Darrell S. Crowe Dec 2014

Hot Streak Characterization In Serpentine Exhaust Nozzles, Darrell S. Crowe

Theses and Dissertations

Modern aircraft of the United States Air Force face increasingly demanding cost, weight, and survivability requirements. Serpentine exhaust nozzles within an embedded engine allow a weapon system to fulfill mission survivability requirements by providing denial of direct line-of-sight into the high-temperature components of the engine. Recently, aircraft have experienced material degradation and failure along the aft deck due to extreme thermal loading. Failure has occurred in specific regions along the aft deck where concentrations of hot gas have come in contact with the surface causing hot streaks. The prevention of these failures will be aided by the accurate prediction of …


A Decision Analysis Framework For Evaluation Of Helmet Mounted Display Alternatives For Fighter Aircraft, Matthew R. Dansereau Dec 2014

A Decision Analysis Framework For Evaluation Of Helmet Mounted Display Alternatives For Fighter Aircraft, Matthew R. Dansereau

Theses and Dissertations

The promise of providing an intuitive and efficient information interface, while allowing the warfighter to perform other critical tasks such as targeting or aircraft control, has led to the growing popularity of Helmet Mounted Displays (HMDs) across the military landscape, especially combat aircraft. Though design and selection of competing systems is critical to optimized performance and safety, structured methods for the evaluation of HMDs are not often used in the acquisition community, leaving selection among alternative designs to the judgment of subject matter experts. However, technical decision-making has been shown to be flawed without the use of a structured decision …


Cloud-Induced Uncertainty For Visual Navigation, Alyssa N. Gutierrez Dec 2014

Cloud-Induced Uncertainty For Visual Navigation, Alyssa N. Gutierrez

Theses and Dissertations

This research addresses the numerical distortion of features due to the presence of clouds in an image. The research aims to quantify the probability of a mismatch between two features in a single image, which will describe the likelihood that a visual navigation system incorrectly tracks a feature throughout an image sequence, leading to position miscalculations. First, an algorithm is developed for calculating transparency of clouds in images at the pixel level. The algorithm determines transparency based on the distance between each pixel color and the average pixel color of the clouds. The algorithm is used to create a dataset …


Improving Non-Linear Approaches To Anomaly Detection, Class Separation, And Visualization, Todd J. Paciencia Dec 2014

Improving Non-Linear Approaches To Anomaly Detection, Class Separation, And Visualization, Todd J. Paciencia

Theses and Dissertations

Linear approaches for multivariate data analysis are popular due to their lower complexity, reduced computational time, and easier interpretation. In many cases, linear approaches produce adequate results; however, non-linear methods may generate more robust transformations, features, and decision boundaries. Of course, these nonlinear methods present their own unique challenges that often inhibit their use. In this research, improvements to existing non-linear techniques are investigated for the purposes of providing better, timely class separation and improved anomaly detection on various multivariate datasets, culminating in application to anomaly detection in hyperspectral imagery. Primarily, kernel-based methods are investigated, with some consideration towards other …


Approximate Dynamic Programming For Military Resource Allocation, Carl R. Parson Dec 2014

Approximate Dynamic Programming For Military Resource Allocation, Carl R. Parson

Theses and Dissertations

This research considers the optimal allocation of weapons to a collection of targets with the objective of maximizing the value of destroyed targets. The weapon-target assignment (WTA) problem is a classic non-linear combinatorial optimization problem with an extensive history in operations research literature. The dynamic weapon target assignment (DWTA) problem aims to assign weapons optimally over time using the information gained to improve the outcome of their engagements. This research investigates various formulations of the DWTA problem and develops algorithms for their solution. Finally, an embedded optimization problem is introduced in which optimization of the multi-stage DWTA is used to …


Optimal Collision Avoidance Trajectories For Unmanned/Remotely Piloted Aircraft, Nathan E. Smith Dec 2014

Optimal Collision Avoidance Trajectories For Unmanned/Remotely Piloted Aircraft, Nathan E. Smith

Theses and Dissertations

The post-911 environment has punctuated the force-multiplying capabilities that Remotely Piloted Aircraft (RPA) provides combatant commanders at all echelons on the battlefield. Not only have unmanned aircraft systems made near-revolutionary impacts on the battlefield, their utility and proliferation in law enforcement, homeland security, humanitarian operations, and commercial applications have likewise increased at a rapid rate. As such, under the Federal Aviation Administration (FAA) Modernization and Reform Act of 2012, the United States Congress tasked the FAA to provide for the safe integration of civil unmanned aircraft systems into the national airspace system (NAS) as soon as practicable, but not later …


Advances In Sca And Rf-Dna Fingerprinting Through Enhanced Linear Regression Attacks And Application Of Random Forest Classifiers, Hiren J. Patel Sep 2014

Advances In Sca And Rf-Dna Fingerprinting Through Enhanced Linear Regression Attacks And Application Of Random Forest Classifiers, Hiren J. Patel

Theses and Dissertations

Radio Frequency (RF) emissions from electronic devices expose security vulnerabilities that can be used by an attacker to extract otherwise unobtainable information. Two realms of study were investigated here, including the exploitation of 1) unintentional RF emissions in the field of Side Channel Analysis (SCA), and 2) intentional RF emissions from physical devices in the field of RF-Distinct Native Attribute (RF-DNA) fingerprinting. Statistical analysis on the linear model fit to measured SCA data in Linear Regression Attacks (LRA) improved performance, achieving 98% success rate for AES key-byte identification from unintentional emissions. However, the presence of non-Gaussian noise required the use …


A Comparison Of Afghanistan, Yuma, Az, And Manufactured Sands Melted On Eb-Pvd Thermal Barrier Coatings, Nathaniel P. Opie Sep 2014

A Comparison Of Afghanistan, Yuma, Az, And Manufactured Sands Melted On Eb-Pvd Thermal Barrier Coatings, Nathaniel P. Opie

Theses and Dissertations

Sand ingestion into military aircraft turbine engines from desert environments have tested the performance and life of the engine. In particular, turbine section blades and nozzles are coated with a molten glass when the sand is heated to melting temperatures. This molten glass attacks protective coatings on the surface of these parts. Further research is needed to understand the sands behavior on thermal barrier coatings (TBC) when heated to melting temperatures. Also, further research is needed with manufactured sand used in current engine testing to understand the sand ingestion discrepancies between test engines and operational engines. In this study natural …


Hyperfine Interactions In The Electron Paramagnetic Resonance Spectra Of Point Defects In Wide-Band-Gap Semiconductors, Eric M. Golden Sep 2014

Hyperfine Interactions In The Electron Paramagnetic Resonance Spectra Of Point Defects In Wide-Band-Gap Semiconductors, Eric M. Golden

Theses and Dissertations

The focus of this research was to acquire definitive experimental data on predominant point defects in three important wide-band-gap semiconductors. Hyperfine interactions in electron paramagnetic resonance spectra were used to characterize the neutral nitrogen acceptor in zinc oxide, to identify a silicon interstitial impurity in titanium dioxide, and to determine the electronic structure of the singly ionized sulfur vacancy in stannous hexathiohypodiphosphate (SPS). Research on the basic properties of these technologically important materials plays a crucial role in the development of advanced optical and electronic systems. Zinc oxide is an electro-optic material with the potential to produce high performance electronics …


Optimal Control Of Fully Routed Air Traffic In The Presence Of Uncertainty And Kinodynamic Constraints, Christopher D. Arendt Sep 2014

Optimal Control Of Fully Routed Air Traffic In The Presence Of Uncertainty And Kinodynamic Constraints, Christopher D. Arendt

Theses and Dissertations

A method is presented to extend current graph-based Air Traffic Management optimization frameworks. In general, Air Traffic Management is the process of guiding a finite set of aircraft, each along its pre-determined path within some local airspace, subject to various physical, policy, procedural and operational restrictions. This research addresses several limitations of current graph-based Air Traffic Management optimization methods by incorporating techniques to account for stochastic effects, physical inertia and variable arrival sequencing. In addition, this research provides insight into the performance of multiple methods for approximating non-differentiable air traffic constraints, and incorporates these methods into a generalized weighted-sum representation …


A Method To Develop Neck Injury Criteria To Aid Design And Test Of Escape Systems Incorporating Helmet Mounted Displays, Jeffrey C. Parr Sep 2014

A Method To Develop Neck Injury Criteria To Aid Design And Test Of Escape Systems Incorporating Helmet Mounted Displays, Jeffrey C. Parr

Theses and Dissertations

HMDs are becoming common human-machine interface equipment in manned military flight, but introducing this equipment into the overall aircraft escape system poses new and significant system design, development, and test concerns. Although HMDs add capabilities, which improve operator performance, the increased capability is often accompanied by increased head supported mass. The increased mass can amplify the risk of pilot neck injury during ejection when compared to lighter legacy helmets. Currently no adequate USAF neck injury criteria exist to effectively guide the requirements, design, and test of escape systems for pilots with HMDs. This research effort presents a novel method to …


A Study Of Slipper And Rail Wear Interaction At Low Speed, Greg V. Cavallaro Jun 2014

A Study Of Slipper And Rail Wear Interaction At Low Speed, Greg V. Cavallaro

Theses and Dissertations

The wear research presented in the work consists of results gathered from adapting a FEM based on a Holloman High Speed Test Track (HHSTT) mission executed in January 2008. The FEM consists of a VascoMax slipper sliding on a stationary AISI-1080 steel rail. The slipper is slid along the rail at speeds of 20 m/s and 40 m/s with complementary vertical velocities of -0.079 m/s and -0.059 m/s, respectively. The surface roughness caused by features such as asperities and valleys of the materials, is simulated in this model by five asperities, 1 micron to 5 microns on the rail and …


The Differential Vector Phase-Locked Loop For Global Navigation Satellite System Signal Tracking, James J. Brewer Jun 2014

The Differential Vector Phase-Locked Loop For Global Navigation Satellite System Signal Tracking, James J. Brewer

Theses and Dissertations

A novel differential vector phase-locked loop (DVPLL) is derived that takes GNSS code-phase and carrier-phase measurements from a base station and uses them to maintain an integer ambiguity resolved quality solution directly in the vector tracking loop of a rover receiver. The only state variables estimated and used to create the replica code and carrier signals from the base station measurements are three position and two clock states for a static test. Closing the individual loops solely through the navigation filter makes this a pure vector method. For short baselines, where differential atmospheric errors are small, the DVPLL can be …


Non-Linear Optimization Applied To Angle-Of-Arrival Satellite-Based Geolocation, Stephen D. Hartzell Jun 2014

Non-Linear Optimization Applied To Angle-Of-Arrival Satellite-Based Geolocation, Stephen D. Hartzell

Theses and Dissertations

Geolocation is a common application for satellite systems. This involves estimating an object's location (herein called the subject) based on noisy satellite data. Many geolocation methods exist; however, none are tailored specifically for the unique problems faced by satellite systems. Some satellites are so far from the subject being localized that by the time the satellite receives a signal from the subject it might have moved appreciably. Furthermore, some satellites or terrestrial sensors may be much closer to the subject than others. Therefore, sensors may need to be weighted based upon their distance to the subject being localized. In addition, …


Scalable System Design For Covert Mimo Communications, Jason R. Pennington Jun 2014

Scalable System Design For Covert Mimo Communications, Jason R. Pennington

Theses and Dissertations

In modern communication systems, bandwidth is a limited commodity. Bandwidth efficient systems are needed to meet the demands of the ever-increasing amount of data that users share. Of particular interest is the U.S. Military, where high-resolution pictures and video are used and shared. In these environments, covert communications are necessary while still providing high data rates. The promise of multi-antenna systems providing higher data rates has been shown on a small scale, but limitations in hardware prevent large systems from being implemented.


Proton Damage Effects On Carbon Nanotube Field-Effect Transistors, Evan R. Kemp Jun 2014

Proton Damage Effects On Carbon Nanotube Field-Effect Transistors, Evan R. Kemp

Theses and Dissertations

This research investigated the effects of proton damage on single-walled carbon nanotube (SWCNT) transistors. The transistors were irradiated by 1.8 MeV protons to determine the damage induced in the SWCNTs and the device substrate using Raman spectroscopy, and to observe the effect on transistor functionality by measuring current-voltage characteristics. Irradiation of the SWCNT transistors to a fluence of 1x1013 protons/cm2 resulted in 67% increase in the Raman D/G peak intensity ratio, while at a fluence of 2x1013 protons/cm2 the increase in the D/G ratio was only 18%, likely due to radiation annealing. Current-voltage measurements indicated an …


Air Force Inspection System: An Application For System-Of-Systems (Sos) Engineering, Joseph R. Lay Jun 2014

Air Force Inspection System: An Application For System-Of-Systems (Sos) Engineering, Joseph R. Lay

Theses and Dissertations

The Air Combat Command (ACC) Inspector General (IG) assesses the operational readiness and combat effectiveness of units by evaluating individual wings. Today's conflicts; however, are waged as a joint force. The Joint Forces Commander (JFC) leverages the resources of the entire military complex to achieve strategic objectives. The synergistic effects, created by the integration of individual weapon systems, produce greater results than the individual components. Evaluating wings outside the joint System of Systems (SoS) architecture does not provide a true assessment of combat readiness. Using a case study method, this research examines the idea of integrating a joint SoS architecture …


Minimization Of The Effects Of Secondary Reactions On Turbine Film Cooling In A Fuel Rich Environment, Andrew T. Shewhart Jun 2014

Minimization Of The Effects Of Secondary Reactions On Turbine Film Cooling In A Fuel Rich Environment, Andrew T. Shewhart

Theses and Dissertations

The demand for increased thrust, higher engine efficiency, and reduced fuel consumption has increased the turbine inlet temperature and pressure in modern gas turbine engines. The outcome of these higher temperatures and pressures is the potential for unconsumed radical species to enter the turbine. Because modern cooling schemes for turbine blades involve injecting cool, oxygen rich air adjacent to the surface, the potential for reaction with radicals in the mainstream flow and augmented heat transfer to the blade arises. This study evaluated various configurations of multiple cylindrical rows of cooling holes in terms of both heat release and effective downstream …


Toward Automating Web Protocol Configuration For A Programmable Logic Controller Emulator, Deanna R. Fink Jun 2014

Toward Automating Web Protocol Configuration For A Programmable Logic Controller Emulator, Deanna R. Fink

Theses and Dissertations

Industrial Control Systems (ICS) remain vulnerable through attack vectors that exist within programmable logic controllers (PLC). PLC emulators used as honeypots can provide insight into these vulnerabilities. Honeypots can sometimes deter attackers from real devices and log activity. A variety of PLC emulators exist, but require manual figuration to change their PLC pro le. This limits their flexibility for deployment. An automated process for configuring PLC emulators can open the door for emulation of many types of PLCs. This study investigates the feasibility of creating such a process. The research creates an automated process for figuring the web protocols of …


Secure Ads-B: Towards Airborne Communications Security In The Federal Aviation Administration's Next Generation Air Transportation System, Richard C. Agbeyibor Mar 2014

Secure Ads-B: Towards Airborne Communications Security In The Federal Aviation Administration's Next Generation Air Transportation System, Richard C. Agbeyibor

Theses and Dissertations

The U.S. Congress has mandated that all aircraft operating within the National Airspace System, military or civilian, be equipped with ADS-B transponders by the year 2020. The ADS-B aircraft tracking system, part of the Federal Aviation Administration's NextGen overhaul of the Air Transportation System, replaces Radar-based surveillance with a more accurate satellite-based surveillance system. However, the unencrypted nature of ADS-B communication poses an operational security risk to military and law enforcement aircraft conducting sensitive missions. The non-standard format of its message and the legacy communication channels used by its transponders make the ADS-B system unsuitable for traditional encryption mechanisms. FPE, …


Characterization And Performance Comparison Of Low-Voltage, High-Speed, Push-Pull And Traveling-Wave Silicon Mach-Zehnder Modulators, Tristan A. Latchu Mar 2014

Characterization And Performance Comparison Of Low-Voltage, High-Speed, Push-Pull And Traveling-Wave Silicon Mach-Zehnder Modulators, Tristan A. Latchu

Theses and Dissertations

The well-known power and memory walls are recognized as the current bottlenecks in computing performance, and with the increasing computational load of commonly run applications, it is necessary to nd ways to alleviate the issues presented by the aforementioned bottlenecks. It is therefore necessary to not focus solely on extracting performance improvement by way of changes to the processing architecture, but rather by holistically improving the computing platform, namely the communications backbone. This work focuses on the characterization and performance comparison of two families of optical data modulators, both fundamentally Mach{Zehnder modulators (MZMs); namely, a modulator with a Push-Pull (PP) …


Selectively Tuning A Buckled Si/Sio2 Membrane Mems Through Joule Heating Actuation And Mechanical Restriction, Kyle K. Ziegler Mar 2014

Selectively Tuning A Buckled Si/Sio2 Membrane Mems Through Joule Heating Actuation And Mechanical Restriction, Kyle K. Ziegler

Theses and Dissertations

This research followed previous work and attempted to modify the spring in two ways. First, a Ti/Au meander resistor was deposited atop the membrane in an effort to actuate the membrane and change the spring constant. Secondly, a series of overhanging cantilevers were attached to the bulk substrate surrounding the membrane in an effort to constrain the membrane buckling deflection to the negative stiffness region. Membrane buckling was investigated through Finite Element analysis (FEA) and analytical equations. Deflections were measured using an interferometric microscope (IFM) and force/deflection measurements were captured using a unique measurement scheme. The results concluded that by …


An Experimental Evaluation Of Image Quality For Various Scenarios In A Chromotomographic System With A Spinning Prism, Kyle J. Dufaud Mar 2014

An Experimental Evaluation Of Image Quality For Various Scenarios In A Chromotomographic System With A Spinning Prism, Kyle J. Dufaud

Theses and Dissertations

A lab and eld based hyperspectral chromotomographic imager has been developed at the Air Force Institute of Technology. It is a prototype used to study the requirements for a space-based system. The imager uses a high speed visible band camera behind a direct-vision prism to image both spatial dimensions and the spectral dimension at the same time. Capturing all 3 simultaneously allows for the hyperspectral imaging of transient events. The prism multiplexes the spectral and spatial information, so tomographic reconstruction algorithms must be used to separate hyperspectral channels. Experiments were conducted to compare reconstructed image quality as a function of …


Memristive Responses Of Jammed Granular Copper Array Sensors To Mechanical Stress, Gary A. Willey Mar 2014

Memristive Responses Of Jammed Granular Copper Array Sensors To Mechanical Stress, Gary A. Willey

Theses and Dissertations

A granular memristive device with the end goal of creating a novel system protection device is introduced in a 1-Dimension array. The electromechanical network will lay the groundwork for future 2-Dimensional and 3-Dimensional devices for simultaneous protection from intrusion. Off the shelf copper spheres with diameter of 710 ± 11microns were found through nano-indentation measurements to have elastic modulus of 106GPa, and compressive yield strength of 729MPa, these spheres were prepared for test in a 1-Dimensional array device. The arrays response to mechanical perturbations modeled by Hertz contact mechanics can be monitored by simultaneous electrical measurements across the multiple metal-insulator-metal …


Improving The Enterprise Requirements And Acquisition Model's Development Test And Evaluation Process Fidelity, Jason W. Sutherlin Mar 2014

Improving The Enterprise Requirements And Acquisition Model's Development Test And Evaluation Process Fidelity, Jason W. Sutherlin

Theses and Dissertations

Shrinking budgets and dynamic military conflicts have driven Department of Defense (DoD) leadership to reform how the military acquires weapon systems with the goal of decreasing program schedules and costs, while maximizing performance. With fifty years of reform, the DoD has been unable to adequately control program schedule objectives. Previous research attempted to support acquisition reforms through modeling and simulation. The Enterprise Requirements and Acquisition Model (ERAM) captures a program's progression through the Defense Acquisition Management System to gain insight into significant delays that impact program schedule and probability of completion. A past unexpected result included the insignificant impact that …


Operational Characteristics Of An Ultra Compact Combustor, Christopher J. Damele Mar 2014

Operational Characteristics Of An Ultra Compact Combustor, Christopher J. Damele

Theses and Dissertations

Ultra Compact Combustors offer unique solutions to minimize engine size and weight. They accomplish this by reducing the number of components in the engine core and perform the combustion in a circumferential cavity that encircles the core flow. Within this cavity, the fuel is injected rich. Burning continues to occur in the vane passage beneath the circumferential cavity which must be completed in a controlled manner prior to the inlet plane of the turbine rotor. Furthermore, the temperature distribution at the exit of the vane passage must be controlled to generate high work extraction from the turbine. The primary metrics …