Physical Sciences and Mathematics Commons^™

Passively Estimating Index Of Refraction For Specular Reflectors Using Polarimetric Hyperspectral Imaging, Jacob A. Martin

Theses and Dissertations

As off-nadir viewing platforms becoming increasingly prevalent in remote sensing, material classification and ID techniques robust to changing viewing geometries must be developed. Traditionally, either reflectivity or emissivity are used for classification, but these quantities vary with viewing angle. Instead, estimating index of refraction may be advantageous as it is invariant with respect to viewing geometry. This work focuses on estimating index of refraction from LWIR (875-1250 wavenumbers) polarimetric hyperspectral radiance measurements.

A Novel Machine Learning Classifier Based On A Qualia Modeling Agent (Qma), Sandra L. Vaughan

Theses and Dissertations

This dissertation addresses a problem found in supervised machine learning (ML) classification, that the target variable, i.e., the variable a classifier predicts, has to be identified before training begins and cannot change during training and testing. This research develops a computational agent, which overcomes this problem. The Qualia Modeling Agent (QMA) is modeled after two cognitive theories: Stanovich's tripartite framework, which proposes learning results from interactions between conscious and unconscious processes; and, the Integrated Information Theory (IIT) of Consciousness, which proposes that the fundamental structural elements of consciousness are qualia. By modeling the informational relationships of qualia, the QMA allows …

Synergistic Effects Of Phase Folding And Wavelet Denoising With Applications In Light Curve Analysis, Andrew M. Armstrong

Theses and Dissertations

The growing size of cosmological data sets is causing the current human-centric approach to cosmology to become impractical. Autonomous data analysis techniques need to be developed in order to advance the field of cosmology. This research examines the benefits of combining two signal analysis techniques, namely phase folding and wavelet denoising, into a newly-developed suite of autonomous light curve analysis tools which includes aspects of component extraction and period detection. The improvements these tools provide, with respect to autonomy and signal quality, are demonstrated using both simulated and real-world light curve data. Although applied to light curve data, the suite …

A Temporal Framework For Hypergame Analysis Of Cyber Physical Systems In Contested Environments, Nicholas S. Kovach

Theses and Dissertations

Game theory is used to model conflicts between one or more players over resources. It offers players a way to reason, allowing rationale for selecting strategies that avoid the worst outcome. Game theory lacks the ability to incorporate advantages one player may have over another player. A meta-game, known as a hypergame, occurs when one player does not know or fully understand all the strategies of a game. Hypergame theory builds upon the utility of game theory by allowing a player to outmaneuver an opponent, thus obtaining a more preferred outcome with higher utility. Recent work in hypergame theory has …

Physical Layer Defenses Against Primary User Emulation Attacks, Joan A. Betances

Theses and Dissertations

Cognitive Radio (CR) is a promising technology that works by detecting unused parts of the spectrum and automatically reconfiguring the communication system's parameters in order to operate in the available communication channels while minimizing interference. CR enables efficient use of the Radio Frequency (RF) spectrum by generating waveforms that can coexist with existing users in licensed spectrum bands. Spectrum sensing is one of the most important components of CR systems because it provides awareness of its operating environment, as well as detecting the presence of primary (licensed) users of the spectrum.

Time Domain Analysis Of Electromagnetic Scattering From Multiple Cavities Embedded In A Ground Plane, Richard P. Uber

Theses and Dissertations

This work examines the scattered fields produced when a transient wave is reflected from an infinite perfect electric conductor (PEC) ground plane with multiple embedded cavities. Incident and reflected waves will be decomposed into transverse magnetic to the z direction (TMz) and transverse electric to the z direction (TEz) polarizations, with primary focus given to the TMz. Cavities may be unfilled, partially filled, or fully filled with non-magnetic dielectric material and no assumptions are made regarding similarity, regularity, or periodicity. The Newmark method is used to discretize time and a variational formulation is presented for each time step. The principle …

A Statistical Approach To Characterize And Detect Degradation Within The Barabasi-Albert Network, Mohd-Fairul Mohd-Zaid

Theses and Dissertations

Social Network Analysis (SNA) is widely used by the intelligence community when analyzing the relationships between individuals within groups of interest. Hence, any tools that can be quantitatively shown to help improve the analyses are advantageous for the intelligence community. To date, there have been no methods developed to characterize a real world network as a Barabasi-Albert network which is a type of network with properties contained in many real-world networks. In this research, two newly developed statistical tests using the degree distribution and the L-moments of the degree distribution are proposed with application to classifying networks and detecting degradation …

Improving The Cybersecurity Of Cyber-Physical Systems Through Behavioral Game Theory And Model Checking In Practice And In Education, Seth T. Hamman

Theses and Dissertations

This dissertation presents automated methods based on behavioral game theory and model checking to improve the cybersecurity of cyber-physical systems (CPSs) and advocates teaching certain foundational principles of these methods to cybersecurity students. First, it encodes behavioral game theory's concept of level-k reasoning into an integer linear program that models a newly defined security Colonel Blotto game. This approach is designed to achieve an efficient allocation of scarce protection resources by anticipating attack allocations. A human subjects experiment based on a CPS infrastructure demonstrates its effectiveness. Next, it rigorously defines the term adversarial thinking, one of cybersecurity educations most important …

Data Driven Device Failure Prediction, Paul L. Jordan

Theses and Dissertations

As society becomes more dependent upon computer systems to perform increasingly critical tasks, ensuring those systems do not fail also becomes more important. Many organizations depend heavily on desktop computers for day to day operations. Unfortunately, the software that runs on these computers is still written by humans and as such, is still subject to human error and consequent failure. A natural solution is to use statistical machine learning to predict failure. However, since failure is still a relatively rare event, obtaining labeled training data to train these models is not trivial. This work presents new simulated fault loads with …

Optical Theory Improvements To Space Domain Awareness, Tyler J. Hardy

Theses and Dissertations

This dissertation focuses on increasing the ability to detect space objects and increase Space Domain Awareness (SDA) with space surveillance sensors through image processing and optical theory. SDA observations are collected through ground-based radar and optical systems as well as space based assets. This research focuses on a ground-based optical telescope system, the Space Surveillance Telescope (SST). By increasing the number of detectable Resident Space Objects (RSOs) through image processing, SDA capabilities can be expanded. This is accomplished through addressing two main degrading factors present in typical SDA sensors; spatial undersampling in the collected data and noise models and assumptions …

Experimental Testing Of A Van De Graaff Generator As An Electromagnetic Pulse Generator, John S. Leahy

Theses and Dissertations

The purpose of this research was to evaluate an existing Van de Graaff generator facility for use as an EMP research tool. In order to assess the Van de Graaff, the unclassified Military Standard 464, which specifies a testing free field wave as having an intensity of 50 kV/m with a time-to-peak, of no more than 5 ns, was used as a baseline for free field analysis and this temporal standard used as a basis for generated currents. Unfortunately, the free field measurements were subject to substantial electronic interference from electromagnetic coupling from internal wall reflections, invalidating the assessment. Therefore …

Evaluation Of Hydrothermally Synthesized Uranium Dioxide For Novel Semiconductor Applications, Christopher M. Young

Theses and Dissertations

Neutron radiation detection is an important part of the national strategy for nonproliferation efforts worldwide. Key to the success of these programs is detector material development which establishes the limits of efficiency, sensitivity, and power usage for a detector of practical use. This research focused upon the study of neutron detection using single crystal actinide compounds, specifically UO2, taking advantage of the successful hydrothermal synthesis of UO2 at the Air Force Research Laboratories. Initial indications are that this material may be of sufficient quality for semiconductor application.

Synaptic Annealing: Anisotropic Simulated Annealing And Its Application To Neural Network Synaptic Weight Selection, Justin R. Fletcher

Theses and Dissertations

Machine learning algorithms have become a ubiquitous, indispensable part of modern life. Neural networks are one of the most successful classes of machine learning algorithms, and have been applied to solve problems previously considered to be the exclusive domain of human intellect. Several methods for selecting neural network configurations exist. The most common such method is error back-propagation. Backpropagation often produces neural networks that perform well, but do not achieve an optimal solution. This research explores the effectiveness of an alternative feed-forward neural network weight selection procedure called synaptic annealing. Synaptic annealing is the application of the simulated annealing algorithm …

Particle Image Velocimetry And Analysis Methods Using Cleanly Seeded Particles In Supersonic Flow, Paul A. Gulotta

Theses and Dissertations

Particle Image Velocimetry (PIV) was successfully conducted in the Air Force Research Lab Mach 3/ Mach 6 Facility (M3M6F) for the first time. Particle response experiments evaluating the performance of dry ice particles across an oblique shock wave were conducted using a 15 degree half-wedge in nominal Mach 3 flow. Solid carbon dioxide particles are generated through rapid expansion of liquid carbon dioxide via a small nozzle within a simple shroud tube or a tube containing static mixing elements. Particles are injected directly into the settling chamber of the Mach 3 tunnel. The particle response of carbon dioxide particles is …

Meeting The Dod’S Tactical Weather Needs Using Cubesats, Shayna K. Mckenney

Theses and Dissertations

This thesis investigates a CubeSat design that uses Commercial-Off-The-Shelf (COTS) components to capture, store, process, and downlink collected terrestrial weather data at resolutions near stat-of-the-art. The weather phenomena to be detected and transmitted in a timely manner are cloud formations, wind profiles, ocean currents, sea state, lightning, temperature profiles, and precipitation. It is hypothesized and shown that the proposed design will provide an improvement on the current U.S. tactical weather collection satellites because of the anticipated increased reliability and lowered cost to build and maintain the proposed CubeSat constellation. The methodology employed a multi-phase approach through the collective research of …

A Multi-Objective Approach To Tactical Maneuvering Within Real Time Strategy Games, Christopher D. Ball

Theses and Dissertations

The real time strategy (RTS) environment is a strong platform for simulating complex tactical problems. The overall research goal is to develop artificial intelligence (AI) RTS planning agents for military critical decision making education. These agents should have the ability to perform at an expert level as well as to assess a players critical decision-making ability or skill-level. The nature of the time sensitivity within the RTS environment creates very complex situations. Each situation must be analyzed and orders must be given to each tactical unit before the scenario on the battlefield changes and makes the decisions no longer relevant. …

Laminar Flame Combustion Diagnostics Using Imaging Fourier Transform Spectroscopy, Michael R. Rhoby

Theses and Dissertations

Laminar flames are an important tool in combustion diagnostics with a host of pre-existing experimental research methods. Currently, however, no method captures time-resolved scalar profile estimates of temperature, and major species concentrations with a single measurement. This work provides IFTS with the capability to measure time-resolved 3D imaging of scalar values in laminar axisymmetric flames. This will make IFTS a useful tool for understanding combustion phenomenon, validating chemical kinetic models, verifying numerical simulations, and system performance estimate. Two algorithms are presented. The first reconstructs spectra as a function of flame period. Through selectively averaging over an ensemble of measurements, interferograms …

Analysis Of Software Design Patterns In Human Cognitive Performance Experiments, Alexander C. Roosma

Theses and Dissertations

As Air Force operations continue to move toward the use of more autonomous systems and more human-machine teaming in general, there is a corresponding need to swiftly evaluate systems with these capabilities. We support this development through software design improvements of the execution of human cognitive performance experiments. This thesis sought to answer the following two research questions addressing the core functionality that these experiments rely on for execution and analysis: 1) What data infrastructure software requirements are necessary to execute the experimental design of human cognitive performance experiments? 2) How effectively does a central data mediator design pattern meet …

The Reliability And Skill Of Air Force Weather’S Ensemble Prediction Suites, Derek A. Burns

Theses and Dissertations

The Ensemble Prediction Suites (EPS) used at the 557th Weather Wing (557 WW) provide probability based forecasts for thousands of worldwide locations. Point Ensemble Probability (PEP) bulletins are tailored specifically to the United States military and its criteria for operationally significant weather. This study assesses the performance of PEPs from each EPS at 17 Continental United States (CONUS) locations. Results from April to October of 2015 show that each EPS is underforecasting ceilings and visibility for most forecast hours at several locations. The underforecasting of ceilings is most severe at Vandenberg AFB, an area prone to frequent marine layer fog …

Simulation, Design, And Test Of Square, Apodized Photon Sieves For High-Contrast, Exoplanet Imaging, Thomas W.N. Dickinson

Theses and Dissertations

A photon sieve is a lightweight, diffractive optic which is well-suited to be a deployable primary for a space telescope. Point spread functions (PSFs) can be altered by shaping and apodizing an aperture, and a PSF that drops rapidly from the peak is desirable for high-contrast imaging. For this reason, square apodized photon sieves were simulated, designed, and tested for high-contrast performance and use in an exoplanet imaging telescope. These sieves were shown to outperform conventional optics and unapodized sieves for high-contrast imaging in a number of tests. New methods were developed for apodizing sieves, measuring PSFs, and characterizing high-contrast …

Capturing Atmospheric Effects On 3-D Millimeter Wave Radar Propagation Patterns, Richard D. Cook

Theses and Dissertations

The need to model millimeter wave (MMW) radar propagation is imperative to proper design of aeronautical, civil, and military systems. Traditional radar propagation modeling is done using a path transmittance with little to no input for weather and atmospheric conditions. As radar advances into the MMW regime, atmospheric effects, such as attenuation and refraction, become more pronounced than at traditional radar wavelengths. The DoD High Energy Laser Joint Technology Offices High Energy Laser End-to-End Operational Simulation (HELEEOS), in combination with the Laser Environmental Effects Definition and Reference (LEEDR) code, is a powerful tool for simulating laser propagation and effects tied …

Kinetics Of Higher Lying Rb States After, Pulsed Excitation Of The D2 Transition In The Presence Of Helium, Austin J. Wallerstein

Theses and Dissertations

The Diode Pumped Alkali Laser (DPAL) is a high power, three-level laser system that employs diode bars to optically excite an alkali metal vapor. It lases along the D₁ transition, between the two lowest energy levels, ²P_1/2 and ²S_1/2. Higher lying energy states are produced at higher population density via energy pooling and multiphoton processes. Pulsed laser excitation of rubidium at approximately 1 MW=cm² has been studied at helium pressure up to 900 Torr. Emissions from energy states as high as 82D suggests modest ionization, though these intensities decrease drastically at buffer gas …

Cross-Subject Continuous Analytic Workload Profiling Using Stochastic Discrete Event Simulation, Joseph J. Giametta

Theses and Dissertations

Operator functional state (OFS) in remotely piloted aircraft (RPA) simulations is modeled using electroencephalograph (EEG) physiological data and continuous analytic workload profiles (CAWPs). A framework is proposed that provides solutions to the limitations that stem from lengthy training data collection and labeling techniques associated with generating CAWPs for multiple operators/trials. The framework focuses on the creation of scalable machine learning models using two generalization methods: 1) the stochastic generation of CAWPs and 2) the use of cross-subject physiological training data to calibrate machine learning models. Cross-subject workload models are used to infer OFS on new subjects, reducing the need to …

Clustering Theory And Data Driven Health Care Strategies, Takayuki Iguchi

Theses and Dissertations

DoD health care requires reform with growing costs causing concerns of decreased military capability. One proposed radical strategy to fix current health care delivery systems is to organize medical teams around patients with similar treatment requirements. This is a clustering problem; how do you partition the set of patients so that each group has similar treatment needs? We provide advances in clustering theory relevant to this new health care strategy. In particular, we create fast certifiably optimal k-means clustering using what is known as Probably Certifiably Correct (PCC) algorithms which achieves state-of-the-art performance under certain models. Inspired by the health …

Deception In Game Theory: A Survey And Multiobjective Model, Austin L. Davis

Theses and Dissertations

Game theory is the study of mathematical models of conflict. It provides tools for analyzing dynamic interactions between multiple agents and (in some cases) across multiple interactions. This thesis contains two scholarly articles. The first article is a survey of game-theoretic models of deception. The survey describes the ways researchers use game theory to measure the practicality of deception, model the mechanisms for performing deception, analyze the outcomes of deception, and respond to, or mitigate the effects of deception. The survey highlights several gaps in the literature. One important gap concerns the benefit-cost-risk trade-off made during deception planning. To address …

A Misuse-Based Intrusion Detection System For Itu-T G.9959 Wireless Networks, Jonathan D. Fuller

Theses and Dissertations

Wireless Sensor Networks (WSNs) provide low-cost, low-power, and low-complexity systems tightly integrating control and communication. Protocols based on the ITU-T G.9959 recommendation specifying narrow-band sub-GHz communications have significant growth potential. The Z-Wave protocol is the most common implementation. Z-Wave developers are required to sign nondisclosure and confidentiality agreements, limiting the availability of tools to perform open source research. This work discovers vulnerabilities allowing the injection of rogue devices or hiding information in Z-Wave packets as a type of covert channel attack. Given existing vulnerabilities and exploitations, defensive countermeasures are needed. A Misuse-Based Intrusion Detection System (MBIDS) is engineered, capable of …

Framework For Evaluating The Readiness Of Cyber First Responders Responsible For Critical Infrastructure Protection, Jungsang Yoon

Theses and Dissertations

First responders go through rigorous training and evaluation to ensure they are adequately prepared for an emergency. As an example, firefighters continually evaluate the readiness of their personnel using a defined set of criteria to measure performance for fire suppression and rescue procedures. From a cyber security standpoint, however, this same set of criteria and rigor is severely lacking for the professionals that must detect, respond to and recover from a cyber-based attack against the nation's critical infrastructure. This research provides a framework for evaluating the readiness of cyber first responders responsible for critical infrastructure protection. The framework demonstrates the …

Cyberspace And Organizational Structure: An Analysis Of The Critical Infrastructure Environment, Michael D. Quigg Ii

Theses and Dissertations

Now more than ever, organizations are being created to protect the cyberspace environment. The capability of cyber organizations tasked to defend critical infrastructure has been called into question by numerous cybersecurity experts. Organizational theory states that organizations should be constructed to fit their operating environment properly. Little research in this area links existing organizational theory to cyber organizational structure. Because of the cyberspace connection to critical infrastructure assets, the factors that influence the structure of cyber organizations designed to protect these assets warrant analysis to identify opportunities for improvement.

This thesis analyzes the cyber‐connected critical infrastructure environment using the dominant …

A Simulation-Based Analysis Of Chemical And Radiological Hazard Zones Adapted To Physical Boundaries, Mickie J. Sundheim

Theses and Dissertations

In the United States, industrial and terrorist use of chemical, biological, radiological, and nuclear (CBRN) materials pose a risk to public safety. During the initial phase of typical CBRN incidents, emergency responders establish hazard zones based on standard distances from published guidelines and recommendations. This research investigates how standard hazard zones change in a real world environment that accounts for physical boundaries. Using a python simulation in ArcGIS®, new hazard zones were created by expanding standard hazard zones to follow nearby roads, railroads, and rivers. The new and standard zones were compared by calculating the population and area affected by …

Pointing Analysis And Design Drivers For Low Earth Orbit Satellite Quantum Key Distribution, Jeremiah A. Specht

Theses and Dissertations

The world relies on encryption to perform critical and sensitive tasks every day. If quantum computing matures, the capability to decode keys and decrypt messages becomes possible. Quantum key distribution (QKD) is a method of distributing secure cryptographic keys which relies on the laws of quantum mechanics. Current implementations of QKD use fiber-based channels which limit the number of users and the distance between users. Satellite-based QKD using free-space channels is proposed as a feasible secure global communication solution. Since a free-space link does not use a waveguide, pointing a transmitter to receiver is required to ensure signal arrival. In …