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A Unified Framework For Solving Multiagent Task Assignment Problems, Kevin Cousin
A Unified Framework For Solving Multiagent Task Assignment Problems, Kevin Cousin
Theses and Dissertations
Multiagent task assignment problem descriptors do not fully represent the complex interactions in a multiagent domain, and algorithmic solutions vary widely depending on how the domain is represented. This issue is compounded as related research fields contain descriptors that similarly describe multiagent task assignment problems, including complex domain interactions, but generally do not provide the mechanisms needed to solve the multiagent aspect of task assignment. This research presents a unified approach to representing and solving the multiagent task assignment problem for complex problem domains. Ideas central to multiagent task allocation, project scheduling, constraint satisfaction, and coalition formation are combined to …
A Hybrid Multi-Robot Control Architecture, Daylond J. Hooper
A Hybrid Multi-Robot Control Architecture, Daylond J. Hooper
Theses and Dissertations
Multi-robot systems provide system redundancy and enhanced capability versus single robot systems. Implementations of these systems are varied, each with specific design approaches geared towards an application domain. Some traditional single robot control architectures have been expanded for multi-robot systems, but these expansions predominantly focus on the addition of communication capabilities. Both design approaches are application specific and limit the generalizability of the system. This work presents a redesign of a common single robot architecture in order to provide a more sophisticated multi-robot system. The single robot architecture chosen for application is the Three Layer Architecture (TLA). The primary strength …
Investigation Of Radio Frequency Discharges And Langmuir Probe Diagnostic Methods In A Fast Flowing Electronegative Background Gas, Nathaniel P. Lockwood
Investigation Of Radio Frequency Discharges And Langmuir Probe Diagnostic Methods In A Fast Flowing Electronegative Background Gas, Nathaniel P. Lockwood
Theses and Dissertations
Discharges in a flowing background gas are used to produce charged and excited species for numerous applications including etching semiconductors and pumping gas discharge lasers (Pinhero and others, 1998). The effect of a flowing background gas on the charged and excited neutral species generation by an RF discharge in a flow tube and the diagnostics of the resulting plasma with a Langmuir probe have been investigated for pressures between 0.001 to 1 Torr and flow velocities up to 1000 m/s. This investigation was performed using a fluid method coupled to a chemical kinetic model and a hybrid Particle-In-Cell/Monte Carlo Collision …
Collision Broadening Using Alkali-Filled, Hollow Core Fibers, Luke P. Rodgers
Collision Broadening Using Alkali-Filled, Hollow Core Fibers, Luke P. Rodgers
Theses and Dissertations
The goal of this research was to demonstrate the possibility of collision broadening in a cesium-filled, hollow-core fiber as an alternative to the proven technique of pressure broadening. Theoretically, alkali electrons should relax from the 2P3/2 to the 2P1/2 level and the absorption spectrum should collisionally broaden due to the presence of fiber walls, as opposed to the more common pressure broadening method. An absorption dip located at 852.34nm was recorded in a pressure broadened comparison leg. This data was used as a baseline during analysis of the fiber leg's data. While the fiber was successfully …
Time Resolution Of Collapse Events During The Progation Of Ultraviolet Filaaments, Teresa J. Fondren
Time Resolution Of Collapse Events During The Progation Of Ultraviolet Filaaments, Teresa J. Fondren
Theses and Dissertations
Long distance propagation, or filamentation, of short, intense laser pulses is suggested to be possible through the balance of two effects: self-focusing, when a nonlinear index of refraction of air is induced by high intensities, and de-focusing, due to the plasma created by the pulse. Applications for filamentation include areas such as remote sensing and directed energy. A split-step spectral propagation simulation is used to model the behavior of a high intensity ultraviolet laser pulse propagating through air. Convergence of femtosecond duration collapses that form on the leading edge of the pulse in the time domain is achieved with an …
A General Quantum Mechanical Method To Predict Positron Spectroscopy, Paul E. Adamson
A General Quantum Mechanical Method To Predict Positron Spectroscopy, Paul E. Adamson
Theses and Dissertations
The nuclear-electronic orbital (NEO) method was modified and extended to positron systems. NEO - second-order Moeller-Plesset perturbation (MP2) energies and annihilation rates were calculated for the positronium hydride (PsH) system, and the effects of basis set size on correlation energies captured with the NEO-MP2 and NEO-full configuration interaction (FCI) methods are compared and discussed. Equilibrium geometries and vibrational energy levels were computed for the LiX and e+LiX (X = H, F, Cl) systems at the MP2 and NEO-MP2 levels. It was found that anharmonicity plays a significant role, specifically in the differences between the vibrational energy levels of …
Phenomenological Model For Infrared Emissions From High-Explosive Detonation Fireballs, Kevin C. Gross
Phenomenological Model For Infrared Emissions From High-Explosive Detonation Fireballs, Kevin C. Gross
Theses and Dissertations
Time-resolved infrared spectra were recently collected via a Fourier-transform spectrometer (FTS) from the detonation fireballs of two types of conventional military munitions (CMM) as well as uncased TNT and four types of enhanced novel explosives (ENEs). The CMM spectra are dominated by continuum emission, and a single-temperature Planckian distribution, modified for atmospheric attenuation, captures most of the variation in the data. Some evidence of selective emission is identified by systematic patterns in the fit residuals. The behavior of these systematic residuals affords a distinction between the two types of CMMs studied. The uncased TNT and ENE spectra appear strongly influenced …
Using Author Topic To Detect Insider Threats From Email Traffic, James S. Okolica, Gilbert L. Peterson, Robert F. Mills
Using Author Topic To Detect Insider Threats From Email Traffic, James S. Okolica, Gilbert L. Peterson, Robert F. Mills
Faculty Publications
One means of preventing insider theft is by stopping potential insiders from becoming actual thieves. This article discusses an approach to assist managers in identifying potential insider threats. By using the Author Topic [Rosen-Zvi Michal, Griffiths Thomas, Steyvers Mark, Smyth Padhraic. The author-topic model for authors and documents. In: Proceedings of the 20th conference on uncertainty in artificial intelligence; 2004. p. 487–94.] clustering algorithm, we discern employees' interests from their daily emails. These interests then provide a means to create an implicit and an explicit social network graph. This approach locates potential insiders by finding individuals who either (1) feel …
Scaling Ant Colony Optimization With Hierarchical Reinforcement Learning Partitioning, Erik J. Dries
Scaling Ant Colony Optimization With Hierarchical Reinforcement Learning Partitioning, Erik J. Dries
Theses and Dissertations
This research merges the hierarchical reinforcement learning (HRL) domain and the ant colony optimization (ACO) domain. The merger produces a HRL ACO algorithm capable of generating solutions for both domains. This research also provides two specific implementations of the new algorithm: the first a modification to Dietterich's MAXQ-Q HRL algorithm, the second a hierarchical ACO algorithm. These implementations generate faster results, with little to no significant change in the quality of solutions for the tested problem domains. The application of ACO to the MAXQ-Q algorithm replaces the reinforcement learning, Q-learning and SARSA, with the modified ant colony optimization method, Ant-Q. …
Multi-Objective Optimization For Speed And Stability Of A Sony Aibo Gait, Christopher A. Patterson
Multi-Objective Optimization For Speed And Stability Of A Sony Aibo Gait, Christopher A. Patterson
Theses and Dissertations
Locomotion is a fundamental facet of mobile robotics that many higher level aspects rely on. However, this is not a simple problem for legged robots with many degrees of freedom. For this reason, machine learning techniques have been applied to the domain. Although impressive results have been achieved, there remains a fundamental problem with using most machine learning methods. The learning algorithms usually require a large dataset which is prohibitively hard to collect on an actual robot. Further, learning in simulation has had limited success transitioning to the real world. Also, many learning algorithms optimize for a single fitness function, …
Collaborative, Trust-Based Security Mechanisms For A National Utility Intranet, Gregory M. Coates
Collaborative, Trust-Based Security Mechanisms For A National Utility Intranet, Gregory M. Coates
Theses and Dissertations
This thesis investigates security mechanisms for utility control and protection networks using IP-based protocol interaction. It proposes flexible, cost-effective solutions in strategic locations to protect transitioning legacy and full IP-standards architectures. It also demonstrates how operational signatures can be defined to enact organizationally-unique standard operating procedures for zero failure in environments with varying levels of uncertainty and trust. The research evaluates layering encryption, authentication, traffic filtering, content checks, and event correlation mechanisms over time-critical primary and backup control/protection signaling to prevent disruption by internal and external malicious activity or errors. Finally, it shows how a regional/national implementation can protect private …
Parallelization Of Ant Colony Optimization Via Area Of Expertise Learning, Adrian A. De Freitas
Parallelization Of Ant Colony Optimization Via Area Of Expertise Learning, Adrian A. De Freitas
Theses and Dissertations
Ant colony optimization algorithms have long been touted as providing an effective and efficient means of generating high quality solutions to NP-hard optimization problems. Unfortunately, while the structure of the algorithm is easy to parallelize, the nature and amount of communication required for parallel execution has meant that parallel implementations developed suffer from decreased solution quality, slower runtime performance, or both. This thesis explores a new strategy for ant colony parallelization that involves Area of Expertise (AOE) learning. The AOE concept is based on the idea that individual agents tend to gain knowledge of different areas of the search space …
A Framework For Analyzing And Mitigating The Vulnerabilities Of Complex Systems Via Attack And Protection Trees, Kenneth S. Edge
A Framework For Analyzing And Mitigating The Vulnerabilities Of Complex Systems Via Attack And Protection Trees, Kenneth S. Edge
Theses and Dissertations
Attack trees have been developed to describe processes by which malicious users attempt to exploit or break complex systems. Attack trees offer a method of decomposing, visualizing, and determining the cost or likelihood of attacks. Attack trees by themselves do not provide enough decision support to system defenders. This research develops the concept of using protection trees to offer a detailed risk analysis of a system. In addition to developing protection trees, this research improves the existing concept of attack trees and develops rule sets for the manipulation of metrics used in the security of complex systems. This research specifically …
Raman Fiber Lasers And Amplifiers Based On Multimode Fibers And Their Applications To Beam Cleanup, Nathan B. Terry
Raman Fiber Lasers And Amplifiers Based On Multimode Fibers And Their Applications To Beam Cleanup, Nathan B. Terry
Theses and Dissertations
Raman fiber lasers (RFLs) and Raman fiber amplifiers (RFAs) in multimode fibers were explored. The RFL based on a graded-index fiber was shown to be very efficient relative to RFLs based on singlemode fibers. Several configurations of the RFL were examined; the beam quality of the Stokes beam depended on the reflectivity of the output coupler and the Stokes power. When used as a beam combiner, the RFL was a highly efficient brightness converter. RFL configurations which used dichroic mirrors were shown to be potentially useful for RFLs based on very large fibers. The forward- and backward-seeded geometries of an …
An Artificial Immune System-Inspired Multiobjective Evolutionary Algorithm With Application To The Detection Of Distributed Computer Network Intrusions, Charles R. Haag, Gary B. Lamont, Paul D. L. Williams, Gilbert L. Peterson
An Artificial Immune System-Inspired Multiobjective Evolutionary Algorithm With Application To The Detection Of Distributed Computer Network Intrusions, Charles R. Haag, Gary B. Lamont, Paul D. L. Williams, Gilbert L. Peterson
Faculty Publications
Today's signature-based intrusion detection systems are reactive in nature and storage-limited. Their operation depends upon catching an instance of an intrusion or virus and encoding it into a signature that is stored in its anomaly database, providing a window of vulnerability to computer systems during this time. Further, the maximum size of an Internet Protocol-based message requires the database to be huge in order to maintain possible signature combinations. In order to tighten this response cycle within storage constraints, this paper presents an innovative Artificial Immune System-inspired Multiobjective Evolutionary Algorithm. This distributed intrusion detection system (IDS) is intended to measure …
Genetic Evolution Of Hierarchical Behavior Structures, Brian G. Woolley, Gilbert L. Peterson
Genetic Evolution Of Hierarchical Behavior Structures, Brian G. Woolley, Gilbert L. Peterson
Faculty Publications
The development of coherent and dynamic behaviors for mobile robots is an exceedingly complex endeavor ruled by task objectives, environmental dynamics and the interactions within the behavior structure. This paper discusses the use of genetic programming techniques and the unified behavior framework to develop effective control hierarchies using interchangeable behaviors and arbitration components. Given the number of possible variations provided by the framework, evolutionary programming is used to evolve the overall behavior design. Competitive evolution of the behavior population incrementally develops feasible solutions for the domain through competitive ranking. By developing and implementing many simple behaviors independently and then evolving …
Efficient Gps Position Determination Algorithms, Thao Nguyen
Efficient Gps Position Determination Algorithms, Thao Nguyen
Theses and Dissertations
This research is aimed at improving the state of the art of GPS algorithms, namely, the development of a closed-form positioning algorithm for a standalone user and the development of a novel differential GPS algorithm for a network of users. The stand-alone user GPS algorithm is a direct, closed-form, and efficient new position determination algorithm that exploits the closed-form solution of the GPS trilateration equations and works in the presence of pseudorange measurement noise for an arbitrary number of satellites in view. A two-step GPS position determination algorithm is derived which entails the solution of a linear regression and updates …
An Infrared Camera Simulation For Estimating Spatial Temperature Profiles And Signal-To-Noise Ratios Of An Airborne Laser-Illuminated Target, David F. Orth
Theses and Dissertations
Airborne Laser testing and evaluation can be aided by developing a spectrally-based infrared camera simulation to explore how the target surface's specular and diffuse reflectivities affect the observed signal-to-noise ratio (SNR) and how the target's temperature in the laser spot can estimated. This simulation provides for the observed irradiance, scaled by atmospheric absorption, to consist of the target's self-emission, reflected background emission, and the path emission from the observer to the target. The observed irradiance is scaled and distributed onto a focal plane array by way of a simulated optical system, whose effects are described by modulation transfer functions. The …
Parallel Fast Multipole Method For Molecular Dynamics, Reid G. Ormseth
Parallel Fast Multipole Method For Molecular Dynamics, Reid G. Ormseth
Theses and Dissertations
We report on a parallel version of the Fast Multipole Method (FMM) implemented in the classical molecular dynamics code, NAMD (Not Another Molecular Dynamics program). This novel implementation of FMM aims to minimize interprocessor communication through the modification of the FMM grid to match the hybrid force and spatial decomposition scheme already present in NAMD. This new implementation has the benefit of replacing all-to-all communications broadcasts with direct communications between nearest neighbors. This results in a significant reduction in the amount of communication compared to earlier attempts to integrate FMM into common molecular dynamics programs. The early performance of FMM …
Aerobic Biodegradation Of Fuel Oxygenates, Adam M. Gutshall
Aerobic Biodegradation Of Fuel Oxygenates, Adam M. Gutshall
Theses and Dissertations
Methyl tert-Butyl Ether (MTBE) is the most commonly used fuel oxygenate in the world. Its recalcitrant nature as well as its chemical properties have led to widespread groundwater contamination. Questions regarding its toxicity have spurred a search for viable oxygenate alternatives. Since biodegradability is a key indicator of a chemical’s environmental impact, this research used three different well-known methods, BOD5, respirometry, and GC analysis, to examine the extent and rates of aerobic biodegradation of MTBE along with tert-butyl alcohol (TBA). The common fuel component toluene was added to some of the samples to determine if the presence of …
Multi-Class Classification Averaging Fusion For Detecting Steganography, Benjamin M. Rodriguez, Gilbert L. Peterson, Sos S. Agaian
Multi-Class Classification Averaging Fusion For Detecting Steganography, Benjamin M. Rodriguez, Gilbert L. Peterson, Sos S. Agaian
Faculty Publications
Multiple classifier fusion has the capability of increasing classification accuracy over individual classifier systems. This paper focuses on the development of a multi-class classification fusion based on weighted averaging of posterior class probabilities. This fusion system is applied to the steganography fingerprint domain, in which the classifier identifies the statistical patterns in an image which distinguish one steganography algorithm from another. Specifically we focus on algorithms in which jpeg images provide the cover in order to communicate covertly. The embedding methods targeted are F5, JSteg, Model Based, OutGuess, and StegHide. The developed multi-class steganalvsis system consists of three levels: (1) …
Steganalysis Feature Improvement Using Expectation Maximization, Benjamin M. Rodriguez, Gilbert L. Peterson, Sos S. Agaian
Steganalysis Feature Improvement Using Expectation Maximization, Benjamin M. Rodriguez, Gilbert L. Peterson, Sos S. Agaian
Faculty Publications
No abstract provided.
Steganography Anomaly Detection Using Simple One Class Classification, Benjamin M. Rodriguez, Gilbert L. Peterson, Sos S. Agaian
Steganography Anomaly Detection Using Simple One Class Classification, Benjamin M. Rodriguez, Gilbert L. Peterson, Sos S. Agaian
Faculty Publications
No abstract provided.
In Pursuit Of An Aptitude Test For Potential Cyberspace Warriors, Tiffiny S. Smith
In Pursuit Of An Aptitude Test For Potential Cyberspace Warriors, Tiffiny S. Smith
Theses and Dissertations
The Air Force has officially assumed the cyberspace mission. To perform this mission well, it is important to employ personnel who have the necessary skill sets and motivation to work in a cyberspace environment. The first step in employing the right people is to screen all possible candidates and select those with an aptitude for acquiring the skill sets and with the motivation to perform this work. This thesis attempts to determine the necessary skills and motivations to perform the cyberspace mission and recommends a screening process to select the candidates with the highest probability for success. Since this mission …
Holes: Ionospheric Scintillation, Gps And Imputation, Robert A. Steenburgh
Holes: Ionospheric Scintillation, Gps And Imputation, Robert A. Steenburgh
Theses and Dissertations
Ionospheric scintillation of Global Positioning System (GPS) signals threatens navigation and military operations by degrading performance or making GPS unavailable. Scintillation is particularly active, although not limited to, a belt encircling the earth within ± 20 degrees of the geomagnetic equator. This belt also hosted roughly half of the completed U.S. military operations in the last decade. The authors examined scintillation data from Ascension Island, United Kingdom, and Ancon, Peru, in the Atlantic longitudinal sector as well as data from Parepare, Indonesia, and Marak Parak, Malaysia, in the Pacific longitudinal sector. From these data, they calculate percent probability of occurrence …
A Multivariate Magnitude Robust Control Chart For Mean Shift Detection And Change Point Estimation, Ryan M. Harrell
A Multivariate Magnitude Robust Control Chart For Mean Shift Detection And Change Point Estimation, Ryan M. Harrell
Theses and Dissertations
Statistical control charts are often used to detect a change in an otherwise stable process. This process may contain several variables affecting process stability. The goal of any control chart is to detect an out-of-control state quickly and provide insight on when the process actually changed. This reduces the off-line time the quality engineer spends assigning causality. In this research, a multivariate magnitude robust chart (MMRC) was developed using a change point model and a likelihood-ratio approach. Here the process is considered in-control until one or more normally distributed process variables permanently and suddenly shifts to out-of-control, stable value. Using …
Internet Protocol Geolocation: Development Of A Delay-Based Hybrid Methodology For Locating The Geographic Location Of A Network Node, John M. Roehl
Internet Protocol Geolocation: Development Of A Delay-Based Hybrid Methodology For Locating The Geographic Location Of A Network Node, John M. Roehl
Theses and Dissertations
Internet Protocol Geolocation (IP Geolocation), the process of determining the approximate geographic location of an IP addressable node, has proven useful in a wide variety of commercial applications. Commercial applications of IP Geolocation include market research, redirection for performance enhancement, restricting content, and combating fraud. The potential for military applications include securing remote access via geographic authentication, intelligence collection, and cyber attack attribution. IP Geolocation methods can be divided into three basic categories based upon what information is used to determine the geographic location of the given IP address: 1) Information contained in databases, 2) information that is leaked during …
Wide Area Search And Engagement Simulation Validation, Michael J. Marlin
Wide Area Search And Engagement Simulation Validation, Michael J. Marlin
Theses and Dissertations
As unmanned aerial vehicles (UAVs) increase in capability, the ability to refuel them in the air is becoming more critical. Aerial refueling will extend the range, shorten the response times, and extend loiter time of UAVs. Executing aerial refueling autonomously will reduce the command and control, logistics, and training efforts associated with fielding UAV systems. Currently, the Air Force Research Lab is researching the various technologies required to conduct automated aerial refueling (AAR). One of the required technologies is the ability to autonomously rendezvous with the tanker. The goal of this research is to determine the control required to fly …
Geospatial Informational Security Risks And Concerns Of The U.S. Air Force Geobase Program, Scott A. Bryant
Geospatial Informational Security Risks And Concerns Of The U.S. Air Force Geobase Program, Scott A. Bryant
Theses and Dissertations
Technological advancements such as Geospatial Information Systems (GIS) and the Internet have made it easier and affordable to share information, which enables complex and time sensitive decisions to be made with higher confidence. Further, advancements in information technology have dramatically increased the ability to store, manage, integrate, and correlate larger amounts of data to improve operational efficiency. However, the same technologies that enable increased productivity also provide increased capabilities to those wishing to do harm. Today’s military leaders are faced with the challenge of deciding how to make geospatial information collected on military installations and organizations available to authorized communities …
Adaptive Gravitational Gossip In Monitoring The Joint Battlespace Infosphere, Edmund Descartes Aban
Adaptive Gravitational Gossip In Monitoring The Joint Battlespace Infosphere, Edmund Descartes Aban
Theses and Dissertations
Future USAF operations will be heavily dependent on having the "right information" at the "right time," and Joint Battlespace Infospheres (JBIs) are poised to fill that role. To do this, JBIs must be ubiquitous -- always accessible, secure and responsive. Of all the literature written regarding JBIs, the most important problem to solve in order to make JBIs work in mobile scenarios are scalability, reliability and adaptability to changing battlefield conditions. This paper explores the use of SBCast, a novel adaptive probabilistic protocol and a delivery mechanism for JBI updates and as a possible solution towards guaranteeing these qualities. It …