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Air Force Institute of Technology

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Articles 2251 - 2280 of 5700

Full-Text Articles in Engineering

Streamlining The Change-Over Protocol For The Rpa Mission Intelligence Coordinator By Way Of Situation Awareness Oriented Design And Discrete Event Simulation, John P. Machuca Mar 2012

Streamlining The Change-Over Protocol For The Rpa Mission Intelligence Coordinator By Way Of Situation Awareness Oriented Design And Discrete Event Simulation, John P. Machuca

Theses and Dissertations

Incredible loiter times coupled with the ability to make extremely detailed collections at significant stand-off distances with a relatively expendable platform has made demand for, and diversity of, Remotely Piloted Aircraft (RPA) operations grow at voracious rates. Conversely, financial resources are becoming increasingly constrained. As such, innovators are looking to maximize the effectiveness of existing personnel and assets by considering concepts such as simultaneous Multiple Aircraft Control (MAC) by a single aircrew. Research has identified procedural inefficiencies in current operations as well as substantial impediments to MAC implementation, including dynamic task saturation and communication challenges. An identified inefficiency afflicting both …

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Optimization Of Nanoscale Zero-Valent Iron For The Remediation Of Groundwater Contaminants, Andrew W. E. Mcpherson Mar 2012

Optimization Of Nanoscale Zero-Valent Iron For The Remediation Of Groundwater Contaminants, Andrew W. E. Mcpherson

Theses and Dissertations

Nanoscale zero-valent iron (nZVI) is an emerging tool for the remediation of groundwater contaminants. The nanoparticles are capable of reductively destroying or immobilizing a wide range of contaminants. Their small size results in a high surface area to mass ratio, making them much more reactive compared to their more-coarse predecessors. Small particle size also allows nZVI particles to be injected directly into contaminated areas via a well, limiting the above-ground footprint and allowing access to contaminated areas that are beyond the reach of some conventional methods. nZVI technology has the potential to facilitate remediation in difficult situations, improve remediation outcomes, …

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Analysis Of The Impact Of Data Normalization On Cyber Event Correlation Query Performance, Smile T. Ludovice Mar 2012

Analysis Of The Impact Of Data Normalization On Cyber Event Correlation Query Performance, Smile T. Ludovice

Theses and Dissertations

A critical capability required in the operation of cyberspace is the ability to maintain situational awareness of the status of the infrastructure elements that constitute cyberspace. Event logs from cyber devices can yield significant information, and when properly utilized they can provide timely situational awareness about the state of the cyber infrastructure. In addition, proper Information Assurance requires the validation and verification of the integrity of results generated by a commercial log analysis tool. Event log analysis can be performed using relational databases. To enhance database query performance, previous literatures affirm denormalization of databases. Yet database normalization can also increase …

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Biodegradation Of Organophosphate Chemical Warfare Agents By Activated Sludge, Steven J. Schuldt Mar 2012

Biodegradation Of Organophosphate Chemical Warfare Agents By Activated Sludge, Steven J. Schuldt

Theses and Dissertations

Organophosphates (OPs) have been widely used as Chemical Warfare Agents (CWAs) as well as pesticides since World War II and still remain a threat to national security. While efforts have been taken at military installations and civilian communities to secure these chemicals and prevent their misuse, a determined adversary could still obtain and deploy them to injure, kill, or instill terror. The lethal properties of this group of compounds are primarily owed to their irreversible inhibition of the enzyme acetyl cholinesterase (AChE) and thus may alter the human nervous system or affect the hormonal balance of children in particular. In …

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An Enhanced Fuselage Ultrasound Inspection Approach For Ishm Purposes, Francisco Ospina Mar 2012

An Enhanced Fuselage Ultrasound Inspection Approach For Ishm Purposes, Francisco Ospina

Theses and Dissertations

This effort constitutes a systems engineering approach in which the materials science, ultrasound structural health monitoring, flight and maintenance operations, and relevant aeronautical policies and programs are involved to explore the evolution and characterization of structural cracks in aircraft fuselage structures in which the loads are varying. During flight, an aircraft fuselage skin and structure are subjected to varied cyclic loads, which can cause embedded cracks and other damage features to change their characteristics due to loading effects. The current research is based in the application of finite element modeling techniques using COMSOL and PZFLEX software to characterize the behavior …

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Analysis Of Leadership In Energy And Environmental Design® Construction In The Air Force, James M. Rozzoni Mar 2012

Analysis Of Leadership In Energy And Environmental Design® Construction In The Air Force, James M. Rozzoni

Theses and Dissertations

The Air Force uses the Leadership in Energy and Environmental Design (LEED) rating system as a third party verification system to ensure sustainable and resource-conscious facilities. The Federal Government has implemented several mandates in recent years that require certain milestones be met for energy reduction, water conservation, renewable energy use, and so forth. This research aims to determine how the Air Force has implemented LEED through credit analysis, and to better understand why LEED is being used in this way. Using a database of 172 military construction projects, the research evaluates the frequency of credit usage individually and by category. …

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The Application Of Sensors On Guardrails For The Purpose Of Real Time Impact Detection, Matthew D. Sturtevant Mar 2012

The Application Of Sensors On Guardrails For The Purpose Of Real Time Impact Detection, Matthew D. Sturtevant

Theses and Dissertations

The United States roadway system has deteriorated over time due to its age, increasing delays in completing preventative maintenance, and the lack of timely repairs following damage to the infrastructure. Proper asset management drives the need for generalized methods to integrate new sensing capabilities into existing Intelligent Transportation Systems in a time efficient and cost effective manner. In this thesis, we present a methodology for the deployment of new sensors into an existing ITS system. The proposed methodology employs a three phase approach that incorporates data modeling, spatial analysis in Geographic Information Systems, and cost optimization to provide enhanced decision …

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Implementing A Quantitative Analysis Design Tool For Future Generation Interfaces, Brandon M. Webster Mar 2012

Implementing A Quantitative Analysis Design Tool For Future Generation Interfaces, Brandon M. Webster

Theses and Dissertations

The implementation of Multi-Aircraft Control (MAC) for use with Remotely Piloted Aircraft (RPA) has resulted in the need of a platform to evaluate interface design. The Vigilant Spirit Control Station (VSCS), developed by the Air Force Research Laboratory, addresses this need by permitting the rapid prototyping of different interface concepts for future MAC-enabled systems. A human-computer interaction (HCI) Index, originally applied to multi-function displays was applied to the prototype Vigilant Spirit interface. A modified version of the HCI Index was successfully applied to perform a quantitative analysis of the baseline VSCS interface and two modified interface designs. The modified HCI …

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Structural Health Monitoring Of M1114 High Mobility Multipurpose Wheeled Vehicle Armor System, Frank T. Sha Mar 2012

Structural Health Monitoring Of M1114 High Mobility Multipurpose Wheeled Vehicle Armor System, Frank T. Sha

Theses and Dissertations

The M1114 High Mobility Multipurpose Wheeled Vehicle (HMMWV) has been the workhorse vehicle of the U.S. Armed Forces in Afghanistan and Iraq. Donald Rumsfeld, Secretary of Defense, was faced with massive public criticism in 2004 for not equipping our military personnel in Afghanistan and Iraq with M1114s that had the proper ballistic armor. In May 2004, a $618M Senate Bill was passed to increase the production level of HMMWVs and improve their ballistic protection capabilities while minimizing additional weight. While the military is taking advantage of using composite armor on the HMMWV, it does not have a rigorous method to …

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A Spatial Risk Analysis Of Oil Refineries Within The United States, Zachary L. Schiff Mar 2012

A Spatial Risk Analysis Of Oil Refineries Within The United States, Zachary L. Schiff

Theses and Dissertations

A risk analysis methodology is necessary to manage the potential effects of oil refinery outages to the increasingly connected, interdependent critical infrastructure of the United States. Following the terrorist attacks of 9/11, the lack of a critical infrastructure risk mitigation strategy was identified as an area for improvement. In both the 9/11 attacks and Hurricane Katrina, cascading failures occurred due to the interdependencies among infrastructures and their spatial relationships. Furthermore, the U.S. military is dependent on oil refining capability and a major shortage could potentially have devastating effects on mission accomplishment. As a result, a need has emerged to better …

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Development Of A Radar-Frequency Metamaterial Measurement And Characterization Apparatus, Stephen I. Faris Mar 2012

Development Of A Radar-Frequency Metamaterial Measurement And Characterization Apparatus, Stephen I. Faris

Theses and Dissertations

The overall purpose of this research was to design, build, and test an apparatus for the measurement and characterization of radar-frequency metamaterial performance in the S-band through Ku-band (2-18 GHz). Measurement and characterization is vital to metamaterial taxonomy and ultimately vital to metamaterial definitions. Thus, the current lack of clarity in metamaterial definitions has served as the primary motivation for pursuing a method for taxonomy and thus, this apparatus. The technical goal of this thesis was to aid in the understanding of a metamaterial's radar-frequency response by developing an apparatus that would take simple, yet significant measurements of a metamaterial's …

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Ofdm-Based Signal Exploitation Using Quadrature Mirror Filter Bank (Qmfb) Processing, Felipe E. Garrido Mar 2012

Ofdm-Based Signal Exploitation Using Quadrature Mirror Filter Bank (Qmfb) Processing, Felipe E. Garrido

Theses and Dissertations

By performing QMFB processing with a given signal it is possible to obtain Frequency-Time (F-T) outputs that represent signal features such as bandwidth (W), center frequency (fc), signal duration (Ts), modulation type (AM, FM, BPSK, QAM, etc), frequency content and time allocation. Because of its unique structure, two widely used signals based on Orthogonal Frequency Division Multiplexing (OFDM) were chosen as signals of interest for demonstration. The general implementation of the QMFB process is described along with the basic structure of OFDM signals related to the physical layer perspective of 802.11a Wi-Fi and 802.16e WiMAX frame structures are described. The …

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Target Classification Of Canonical Scatterers Using Classical Estimation And Dictionary Based Techniques, G. Barry Hammond Ii Mar 2012

Target Classification Of Canonical Scatterers Using Classical Estimation And Dictionary Based Techniques, G. Barry Hammond Ii

Theses and Dissertations

This research effort will utilize a hierarchical dictionary-based approach for canonical shape classification within measured synthetic aperture radar (SAR) phase history data. This primary goal of this research is to develop an efficient framework for dictionary based SAR feature extraction using modi ed 3-D radar scattering models. Previous work in this area relies on maximum likelihood (ML) estimation and similar approaches to extract shapes using 2-D signal models. We include characterizations of shape model redundancies caused by similar shape scattering responses. Simulated SAR collection methods, including frequency, elevation aspect, and polarization diversities, are modeled to show reductions in inter-atom correlation. …

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The Effects Of Cognitive Jamming On Wireless Sensor Networks Used For Geolocation, Michael A. Huffman Mar 2012

The Effects Of Cognitive Jamming On Wireless Sensor Networks Used For Geolocation, Michael A. Huffman

Theses and Dissertations

The increased use of Wireless Sensor Networks (WSN) for geolocation has led to an increased reliance on this technology. Jamming, protecting jamming, and detecting jamming in a WSN are areas of study that have greatly increased in interest. This research uses simulations and data collected from hardware experiments to test the effects of jamming on a WSN. Hardware jamming was tested using a Universal Software Radio Peripheral (USRP) Version 2 to assess the effects of jamming on a cooperative network of Java Sun SPOTs. The research combines simulations and data collected from the hardware experiments to see the effects of …

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Binary Classification Of An Unknown Object Through Atmospheric Turbulence Using A Polarimetric Blind-Deconvolution Algorithm Augmented With Adaptive Degree Of Linear Polarization Priors, Mu J. Kim Mar 2012

Binary Classification Of An Unknown Object Through Atmospheric Turbulence Using A Polarimetric Blind-Deconvolution Algorithm Augmented With Adaptive Degree Of Linear Polarization Priors, Mu J. Kim

Theses and Dissertations

This research develops an enhanced material-classification algorithm to discriminate between metals and dielectrics using passive polarimetric imagery degraded by atmospheric turbulence. To improve the performance of the existing technique for near-normal collection geometries, the proposed algorithm adaptively updates the degree of linear polarization (DoLP) priors as more information becomes available about the scene. Three adaptive approaches are presented. The higher-order super-Gaussian method fits the distribution of DoLP estimates with a sum of two super-Gaussian functions to update the priors. The Gaussian method computes the classification threshold value, from which the priors are updated, by fitting the distribution of DoLP estimates …

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Augmenting The Global Positioning System With Foreign Navigation Systems And Alternative Sensors, Christopher B. Killion Mar 2012

Augmenting The Global Positioning System With Foreign Navigation Systems And Alternative Sensors, Christopher B. Killion

Theses and Dissertations

The United States Global Positioning System (GPS), with its great accuracy, receives extensive use by civilians and military organizations throughout the world. However, in areas with limited or partially obstructed views of the sky, such as amongst tall buildings or imposing geographic features, a position solution can be difficult or impossible to obtain as the limited view of the sky decreases the number of visible satellites. Augmenting the GPS constellation by receiving signals from foreign satellite navigation systems as well as using measurements from inertial and barometric sensors can increase the availability of a position solution in a degraded reception …

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Exploiting The Automatic Dependent Surveillance-Broadcast System Via False Target Injection, Domenic Magazu Iii Mar 2012

Exploiting The Automatic Dependent Surveillance-Broadcast System Via False Target Injection, Domenic Magazu Iii

Theses and Dissertations

A new aircraft surveillance system, Automatic Dependent Surveillance-Broadcast (ADS-B), is being introduced by the Federal Aviation Administration (FAA) with mandated implementation in the United States by the year 2020. The rapid deployment of the system with current test-beds spread across the U.S. leaves very little chance for anyone to test the abilities of the system and more importantly the flaws of the system. The research conducted within this thesis explores some of the weaknesses of the system to include the relative ease with which false aircraft targets can be injected. As part of a proof of concept, false ADS-B messages …

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Uhf Antenna Design For Afit Random Noise Radar, Matthew T. Ludwig Mar 2012

Uhf Antenna Design For Afit Random Noise Radar, Matthew T. Ludwig

Theses and Dissertations

The design of a small ultra-high frequency (UHF) antenna for an ultra-wideband (UWB) random noise radar (RNR) system was undertaken to improve system bandwidth and reduce overall system size. The Vivaldi dipole antenna class showed the greatest potential for high performance in this specific application. After extensive computer simulation, three designs were built using two printed circuit board antenna construction methods. The antipodal chopped Vivaldi dipole antenna, built with a milling machine, achieved a wider bandwidth and more uniform spectral performance characteristics. Though current results show improvement over the current log-periodic antenna (LPA) used on the system, greater performance could …

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External Verification Of Scada System Embedded Controller Firmware, Lucille R. Mcminn Mar 2012

External Verification Of Scada System Embedded Controller Firmware, Lucille R. Mcminn

Theses and Dissertations

Critical infrastructures such as oil and gas pipelines, the electric power grid, and railways, rely on the proper operation of supervisory control and data acquisition (SCADA) systems. Current SCADA systems, however, do not have sufficient tailored electronic security solutions. Solutions available are developed primarily for information technology (IT) systems. Indeed, the toolkit for SCADA incident prevention and response is unavailing as the operating parameters associated with SCADA systems are different from IT systems. The unique environment necessitates tailored solutions. Consider the programmable logic controllers (PLCs) that directly connect to end physical systems for control and monitoring of operating parameters -- …

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Ladar Range Image Interpolation Exploiting Pulse Width Expansion, Jeramy W. Motes Mar 2012

Ladar Range Image Interpolation Exploiting Pulse Width Expansion, Jeramy W. Motes

Theses and Dissertations

Laser Detection and Ranging (LADAR) systems produce both a range image and an intensity image by measuring the intensity of light reflected off a surface target. When the transmitted LADAR pulse strikes a sloped surface, the returned pulse is expanded temporally. This characteristic of the reflected laser pulse enables the possibility of estimating the gradient of a surface. This study estimates the gradient of the surface of an object from a modeled LADAR return pulse that includes accurate probabilistic noise models. The range and surface gradient estimations are incorporated into a novel interpolator that facilitates an effective three dimensional (3D) …

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Timing Variations In A Magnetic Pulse Compression Circuit, Jeremy S. Oliver Mar 2012

Timing Variations In A Magnetic Pulse Compression Circuit, Jeremy S. Oliver

Theses and Dissertations

The magnetic pulse compression (MPC) circuit uses saturable core inductors and capacitors to compress the width of a pulse. This substantially increases the peak power of the initially applied pulse. The saturable inductor exhibits a hysteresis curve behavior. One particular problem with these MPC circuits is timing variances in the pulse rate of the system. This work models the unique characteristics and signatures of the timing variations of magnetic switches and pulse compressors. The hysteresis curve of the saturable inductor was created by using a nonlinear inductor and a nonlinear resistor in parallel as a substitute for saturable inductors. The …

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Passive Multistatic Radar Imaging Using An Ofdm Based Signal Of Opportunity, Matthew B. P. Rapson Mar 2012

Passive Multistatic Radar Imaging Using An Ofdm Based Signal Of Opportunity, Matthew B. P. Rapson

Theses and Dissertations

This paper demonstrates a proof of concept in using an OFDM-based signal of opportunity for SAR imaging purposes within a passive, multistatic radar construct. Two signal processing methods have been proposed to create phase history data. The same methods are applied in both a simulated software model and an experimental data collection environment to produce simulated SAR images using the CBP imaging algorithm. The images generated from both the experimental and simulated data were observed to be consistent with each other and with expectations in terms of resolution. Coherent addition of the images results in improved image resolution due to …

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Simultaneous Range-Velocity Processing And Snr Analysis Of Afit's Random Noise Radar, T. Joel Thorson Mar 2012

Simultaneous Range-Velocity Processing And Snr Analysis Of Afit's Random Noise Radar, T. Joel Thorson

Theses and Dissertations

This paper presents two research objectives aimed at advancing the AFIT RNR signal processing algorithm and modeling capability toward the overarching goal of performing collision avoidance on an autonomous vehicle. In both research efforts, analytical, simulated, and measured results are provided and used to draw research conclusions. The first research effort is aimed at reducing the memory required for 2D processing in the time domain in order to distribute the processing algorithm across hundreds of processors on a GPU. Distributed processing reduces the overall 2D processing time and the feasibility of a near real-time implementation is studied. The second effort …

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Application Of Game Theory To Improve The Defense Of The Smart Grid, Keith J. Ross Mar 2012

Application Of Game Theory To Improve The Defense Of The Smart Grid, Keith J. Ross

Theses and Dissertations

This thesis presents the development and evaluation of a distributed agent based system using reputation based trust and game theoretic techniques to improve the defense of the future smart grid from cyber-attack and equipment malfunctions. Future smart grid capabilities promise to leverage network technologies to revolutionize the production, transmission, distribution and consumption of electrical power. However, the internet like communication also increase the power grid's vulnerability to cyber-attack. This thesis uses simulation linking power systems with communication networks to demonstrate the benefits of a Distributed Decision Making Communication Enable Special Protection System (SPS) using reputation based trust and game theory …

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Air-To-Air Missile Vector Scoring, Nicholas Sweeney Mar 2012

Air-To-Air Missile Vector Scoring, Nicholas Sweeney

Theses and Dissertations

An air-to-air missile vector scoring system is proposed for test and evaluation applications. Three different linear missile dynamics models are considered: a six-state constant velocity model and nine-state constant acceleration and three-dimensional coordinated turn models. Frequency modulated continuous wave radar sensors, carefully located to provide spherical coverage around the target, provide updates of missile kinematic information relative to a drone aircraft. Data from the radar sensors is fused with predictions from one of the three missile models using either an extended Kalman filter, an unscented Kalman filter or a particle filter algorithm. The performance of all nine model/filter combinations are …

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Distributed Localization Of Active Transmitters In A Wireless Sensor Network, Oba L. Vincent Mar 2012

Distributed Localization Of Active Transmitters In A Wireless Sensor Network, Oba L. Vincent

Theses and Dissertations

In today's military environment, emphasis has been placed on bandwidth efficiency and total use of the available spectrum. Current communication standards divide the spectrum into several different frequency bands, all of which are assigned to one or multiple primary users. Cognitive Radio utilizes potential white spaces that exist between currently defined channels or in time. One under-explored dimension of white space exploration is spatial. If a frequency band is being used in one region, it may be underutilized, or not occupied in another. Using an active localization method can allow for the discovery of spatial white; trying to spatially map …

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An Inquiry: Effectiveness Of The Complex Empirical Mode Decomposition Method, The Hilbert-Huang Transform, And The Fast-Fourier Transform For Analysis Of Dynamic Objects, Kristen L. Wallis Mar 2012

An Inquiry: Effectiveness Of The Complex Empirical Mode Decomposition Method, The Hilbert-Huang Transform, And The Fast-Fourier Transform For Analysis Of Dynamic Objects, Kristen L. Wallis

Theses and Dissertations

A review of current signal analysis tools show that new techniques are required for an enhanced fidelity or data integrity. Recently, the Hilbert-Huang transform (HHT) and its inherent property, the Empirical Mode Decomposition (EMD) technique, have been formerly investigated. The technique of Complex EMD (CEMD) was also explored. The scope of this work was to assess the CEMD technique as an innovative analysis tool. Subsequent to this, comparisons between applications of the Hilbert transform (HT) and the Fast-Fourier transform (FFT) were analyzed. MATLAB was implemented to model signal decomposition and the execution of mathematical transforms for generating results. The CEMD …

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A Performance Analysis Of The Optimized Link State Routing Protocol Using Voice Traffic Over Mobile Ad Hoc Networks, André Wolf Mar 2012

A Performance Analysis Of The Optimized Link State Routing Protocol Using Voice Traffic Over Mobile Ad Hoc Networks, André Wolf

Theses and Dissertations

Mobile ad hoc networks (MANETs) have grown in popularity over the past decade and are increasingly considered for time-sensitive multimedia applications. The impact of various routing protocols on voice traffic using different IEEE 802.11 extensions has been investigated via analytical models, simulations and experimental test beds. Many studies determined that optimized link state routing (OLSR) is a suitable routing protocol to support voice over internet protocol (VoIP) conversations. This research expands upon this understanding by determining the point at which voice traffic is no longer feasible in an ad hoc environment and determines which audio codec is best suited for …

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Theoretical Study Of The Effects Of Di-Muonic Molecules On Muon-Catalyzed Fusion, Eugene V. Sheely Mar 2012

Theoretical Study Of The Effects Of Di-Muonic Molecules On Muon-Catalyzed Fusion, Eugene V. Sheely

Theses and Dissertations

This document presents a theoretical study di-muonic hydrogen and helium molecules that have the potential of enhancing the muon-catalyzed fusion reaction rate. In order to study these di-muonic molecules a method of non-adiabatic quantum mechanics referred to as a General Particle Orbital (GPO) method was developed. Three mechanisms that have the possibility of enhancing the muon-catalyzed fusion rate were discovered. Two involve the formation of di-muonic hydrogen molecules, and the other uses di-muonic molecules to liberate muons stuck to 3He nuclei. The effects of muon spin on dimuonic hydrogen molecules was studied. The nuclear separation in di-muonic hydrogen molecules …

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Using Qr Factorization For Real-Time Anomaly Detection Of Hyperspectral Images, Kelly R. Bush Mar 2012

Using Qr Factorization For Real-Time Anomaly Detection Of Hyperspectral Images, Kelly R. Bush

Theses and Dissertations

Anomaly detection has been used successfully on hyperspectral images for over a decade. However, there is an ever increasing need for real-time anomaly detectors. Historically, anomaly detection methods have focused on analysis after the entire image has been collected. As useful as post-collection anomaly detection is, there is a great advantage to detecting an anomaly as it is being collected. This research is focused on speeding up the process of detection for a pre-existing method, Linear RX, which is a variation on the traditional Reed-Xiaoli detector. By speeding up the process of detection, it is possible to create a real-time …

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