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Articles 1 - 17 of 17
Full-Text Articles in Engineering
Consistency Results For The Roc Curves Of Fused Classifiers, Kristopher S. Bjerkaas
Consistency Results For The Roc Curves Of Fused Classifiers, Kristopher S. Bjerkaas
Theses and Dissertations
The U.S. Air Force is researching the fusion of multiple classifiers. Given a finite collection of classifiers to be fused, one seeks a new classifier with improved performance. An established performance quantifier is the Receiver Operating Characteristic (ROC) curve, which allows one to view the probability of detection versus the probability of false alarm in one graph. Previous research shows that one does not have to perform tests to determine the ROC curve of this new fused classifier. If the ROC curve for each individual classifier has been determined, then formulas for the ROC curve of the fused classifier exist …
Quantifying Initial Condition And Parametric Uncertainties In A Nonlinear Aeroelastic System With An Efficient Stochastic Algorithm, Daniel R. Millman
Quantifying Initial Condition And Parametric Uncertainties In A Nonlinear Aeroelastic System With An Efficient Stochastic Algorithm, Daniel R. Millman
Theses and Dissertations
There is a growing interest in understanding how uncertainties in flight conditions and structural parameters affect the character of a limit cycle oscillation (LCO) response, leading to failure of an aeroelastic system. Uncertainty quantification of a stochastic system (parametric uncertainty) with stochastic inputs (initial condition uncertainty) has traditionally been analyzed with Monte Carlo simulations (MCS). Probability density functions (PDF) of the LCO response are obtained from the MCS to estimate the probability of failure. A candidate approach to efficiently estimate the PDF of an LCO response is the stochastic projection method. The objective of this research is to extend the …
Estimating Equatorial F-Region Daytime Vertical E X B Drift Velocities From Ground-Based Magnetometer Measurements In The Philippine Longitude Sector, Shauna M. Kinkela
Estimating Equatorial F-Region Daytime Vertical E X B Drift Velocities From Ground-Based Magnetometer Measurements In The Philippine Longitude Sector, Shauna M. Kinkela
Theses and Dissertations
Ionospheric disturbances can severely impact Department of Defense (DoD) systems, such as radar. satellite. and navigation technologies. Forecasting disturbances and describing the Earth's ionosphere, in turn, relies upon innovative computer-based models that gather input parameters from ground and space-borne observations and empirical models for ionospheric drivers. Equatorial E x B drift velocities are significant input parameters that go into many ionospheric models, because they help describe vertical plasma motions near the magnetic equator. Previous work by Anderson, et al 2002 has demonstrated the ability to derive Peruvian longitude sector, daytime vertical E x B drifts from ground-based magnetometer data. The …
Comparative Study On The Use Of Coherent Radar-Derived Electric Fields Vs. Statistical Electric Fields For The Initialization Of A High-Latitude Ionospheric Model, Christopher M. Hogue
Comparative Study On The Use Of Coherent Radar-Derived Electric Fields Vs. Statistical Electric Fields For The Initialization Of A High-Latitude Ionospheric Model, Christopher M. Hogue
Theses and Dissertations
The structure and time development of the magnetosphere-ionosphere system have significant impacts on the Air Force and its mission. Specifically, an accurate knowledge of ionospheric plasma densities is important for the operation of many Air Force systems. This research analyzes plasma density structure development through comparing two distinct electric field models. The two models compared here are a commonly used statistical model created by Heppner and Maynard 1987, and a more recently developed model using real-time coherent radar measurements from the SuperDARN radar network. Ionospheric simulations were run using Utah State University s Time-Dependent Ionospheric Model (TDIM) with the two …
Deviation Of Time-Resolved Luminescence Dynamics In Mwir Semiconductor Materials From Carrier Recombination Theory Predictions, Peter M. Johnson
Deviation Of Time-Resolved Luminescence Dynamics In Mwir Semiconductor Materials From Carrier Recombination Theory Predictions, Peter M. Johnson
Theses and Dissertations
Time resolved luminescence spectroscopy was used to characterize luminescence decay curves for a bulk InAs sample and an InAsSb type-I quantum-well sample over the first 3ns following excitation. The luminescence decay curves were then converted to carrier densities and used to find recombination coefficients that provided the least-squared-error solution of the rate equation describing carrier recombination. Recombination coefficients describing Shockley Read-Hall (ASRH) radiative (Brad) and Auger (CAug) recombination were determined at two different temperatures and four excitation powers, then analyzed for consistency and physical significance. For all of the resulting least …
An Analysis Of Electromagnetic Interference (Emi) Of Ultra Wideband(Uwb) And Ieee 802.11a Wireless Local Area Network (Wlan) Employing Orthogonal Frequency Division Multiplexing (Ofdm), Juan Lopez Jr.
Theses and Dissertations
Military communications require the rapid deployment of mobile, high-bandwidth systems. These systems must provide anytime, anywhere capabilities with minimal interference to existing military, private, and commercial communications. Ultra Wideband (UWB) technology is being advanced as the next generation radio technology and has the potential to revolutionize indoor wireless communications. The ability of UWB to mitigate multipath fading, provide high-throughput data rates (e.g., greater than 100 Mbps), provide excellent signal penetration (e.g., through walls), and low implementation costs makes it an ideal technology for a wide range of private and public sector applications. Preliminary UWB studies conducted by The Institute for …
Optical Characterization And Modeling Of Compositionally Matched Indium Arsenide-Antimonide Bulk And Multiple Quantum Well Semiconductors, Scott C. Phillips
Optical Characterization And Modeling Of Compositionally Matched Indium Arsenide-Antimonide Bulk And Multiple Quantum Well Semiconductors, Scott C. Phillips
Theses and Dissertations
Indium arsenide-antimonide (InAsSb) semiconductors have been determined to emit in the 3-5 micrometer range, the window of interest for countermeasures against infrared electro-optical threats. This experiment set out to cross the bulk to quantum well characterization barrier by optically characterizing two sets of compositionally matched type I quantum well and bulk well material samples. Absorption measurements determined the band gap energy of the bulk samples and the first allowed subband transition for the quantum wells. By collecting absorption spectra at different temperatures, the trend of the energy transitions was described by fitting a Varshni equation to them. The expected result …
Agent Based Simulation Seas Evaluation Of Dodaf Architecture, Gregory V. Destefano
Agent Based Simulation Seas Evaluation Of Dodaf Architecture, Gregory V. Destefano
Theses and Dissertations
With Department of Defense (DoD) weapon systems being deeply rooted in the command, control, communications, computers, intelligence, surveillance, and reconnaissance (C4ISR) structure, it is necessary for combat models to capture C4ISR effects in order to properly assess military worth. Unlike many DoD legacy combat models, the agent based model System Effectiveness and Analysis Simulation (SEAS) is identified as having C4ISR analysis capabilities. In lieu of requirements for all new DoD C4ISR weapon systems to be placed within a DoD Architectural Framework (DoDAF), investigation of means to export data from the Framework to the combat model SEAS began. Through operational, system, …
An Analysis Of Coast Guard Hh-65 Engine Reliability: A Comparison Of Malfunctions To Component Removals, Donna L. Cottrell
An Analysis Of Coast Guard Hh-65 Engine Reliability: A Comparison Of Malfunctions To Component Removals, Donna L. Cottrell
Theses and Dissertations
The Coast Guard HH-65 helicopter experienced 31 in-flight loss of power incidents during FY 2003 and 21 during the first two months of FY 2003. Concurrent with this apparent decrease in reliability, the Coast Guard seeks ways to expand the HH- 65’s Airborne Use of Force capabilities as a result of the September 11th, 2001 terrorists’ attacks. This study is an exploratory, empirical analysis of engine and airframe component replacements as related to engine mishaps and reliability in the HH-65. We use contingency table analysis, ordinary least squares regression, and logistic regression to examine the mishap history and component replacement …
Swarm Based Implementation Of A Virtual Distributed Database System In A Sensor Network, Wen C. Lee
Swarm Based Implementation Of A Virtual Distributed Database System In A Sensor Network, Wen C. Lee
Theses and Dissertations
The deployment of unmanned aerial vehicles (UAVs) in recent military operations has had success in carrying out surveillance and combat missions in sensitive areas. An area of intense research on UAVs has been on controlling a group of small-sized UAVs to carry out reconnaissance missions normally undertaken by large UAVs such as Predator or Global Hawk. A control strategy for coordinating the UAV movements of such a group of UAVs adopts the bio-inspired swarm model to produce autonomous group behavior. This research proposes establishing a distributed database system on a group of swarming UAVs, providing for data storage during a …
Making The Business Case For Sustainable Design In The Department Of Defense, David M. Warnke
Making The Business Case For Sustainable Design In The Department Of Defense, David M. Warnke
Theses and Dissertations
Buildings are one of the largest consumers of natural resources, a major source of ecological pollution, and occasionally toxic to human health. Sustainable design is the common term associated with buildings which, during their construction, use, and eventual disposal, seek to minimize their negative impact on the environment and human health. The U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) rating system helps to assess a building's sustainability level. In the Federal Government's push to set the example for the rest of the nation, nearly every Federal Agency has chosen to adopt the LEED assessment tool. Each …
Modeling A Field Application Of In Situ Bioremediation Of Perchlorate-Contaminated Groundwater Using Horizontal Flow Treatment Wells (Hftws), Peter G. Chosa
Modeling A Field Application Of In Situ Bioremediation Of Perchlorate-Contaminated Groundwater Using Horizontal Flow Treatment Wells (Hftws), Peter G. Chosa
Theses and Dissertations
Perchlorate contaminated groundwater is rapidly becoming a significant environmental remediation issue for the Department of Defense. In this study, an existing numerical model that simulates the operation of a Horizontal Flow Treatment Well (HFTW) system to effect the in situ biodegradation of perchlorate through the addition of an electron donor is modified to include a submodel that describes bioclogging. Bioclogging restricts flow out of the HFTW due to the accumulation of biomass directly adjacent to the well. The modified model is then applied to an existing perchlorate contaminated site that will be used for an evaluation of the HFTW technology. …
Atmospheric Simulation Using A Liquid Crystal Wavefront Controlling Device, Matthew R. Brooks
Atmospheric Simulation Using A Liquid Crystal Wavefront Controlling Device, Matthew R. Brooks
Theses and Dissertations
Test and evaluation of laser warning devices is important due to the increased use of laser devices in aerial applications. In this thesis, an atmospheric aberrating system is deve1oped to enable in-1ab testing of laser warning devices. This system employs laser 1ight at 632.8nm from a He1ium-Neon source and a spatial light modulator (SLM) to cause phase changes using a birefringent liquid crystaJ material. Before the system can be used, the SLM phase response must be quantified to ensure proper manipulation of index of refrnction. Additionally, diffraction from the SLM and rea1-world system scaling are addressed. Once completed, the atmospheric …
A Rapidly-Converging Alternative To Source Iteration For Solving The Discrete Ordinates Radiation Transport Equations In Slab Geometry, Nicholas J. Wager
A Rapidly-Converging Alternative To Source Iteration For Solving The Discrete Ordinates Radiation Transport Equations In Slab Geometry, Nicholas J. Wager
Theses and Dissertations
I present a numerical technique to solve the time independent Boltzmann Transport Equation for the transport of neutrons and photons. The technique efficiently solves the discrete ordinates equations with a new iteration scheme. I call this new scheme the angle space distribution iteration method because it combines a non-linear, high angular-resolution flux approximation within individual spatial cells with a coarse angular-resolution flux approximation that couples all cells in a spatial mesh. This shown to be an efficient alternative to source iteration. The new method is implemented using the step characteristic and exponential characteristic spatial quadrature schemes. The latter was introduced …
Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant
Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant
Theses and Dissertations
Chlorinated solvents have been used in industrial cleaning and degreasing processes in the United States since the early 1900s, and their induction into the environment increased significantly with the growth of industrial processes over the past century. PCE, TCE and their daughter products have been associated with a number of human health concerns and are currently the most common contaminants found in groundwater in the United States. Wetlands possess characteristics necessary for the complete degradation of chlorinated ethenes by microorganisms via anaerobic and aerobic regions that foster the necessary oxidation-reduction conditions. Organic acid and inorganic anion concentrations were evaluated in …
Application Of Horizontal Flow Treatment Wells For In Situ Treatment Of Mtbe-Contaminated Groundwater, Preston F. Rufe
Application Of Horizontal Flow Treatment Wells For In Situ Treatment Of Mtbe-Contaminated Groundwater, Preston F. Rufe
Theses and Dissertations
This study utilized a three-dimensional numerical model to evaluate the potential application of HFTWs to manage MTBE-contaminated groundwater. HFTWs consist of two dual-screened treatment wells. One well operates in an upflow mode, with MTBE-contaminated water extracted from an aquifer through a screen in the deep portion of an aquifer and injected into the aquifer through a shallow well screen, while the adjacent well operates in a downflow mode, extracting water from the shallow zone of the aquifer and injecting it into the deep zone. As the MTBE-contaminated water flows through the wells, an electron acceptor and/or another electron donor is …
An Investigation Of The Effects Of Correlation, Autocorrelation, And Sample Size In Classifier Fusion, Nathan J. Leap
An Investigation Of The Effects Of Correlation, Autocorrelation, And Sample Size In Classifier Fusion, Nathan J. Leap
Theses and Dissertations
This thesis extends the research found in Storm, Bauer, and Oxley, 2003. Data correlation effects and sample size effects on three classifier fusion techniques and one data fusion technique were investigated. Identification System Operating Characteristic Fusion (Haspert, 2000), the Receiver Operating Characteristic Within Fusion method (Oxley and Bauer, 2002), and a Probabilistic Neural Network were the three classifier fusion techniques; a Generalized Regression Neural Network was the data fusion technique. Correlation was injected into the data set both within a feature set (autocorrelation) and across feature sets for a variety of classification problems, and sample size was varied throughout. Total …