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2001

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Validation And Assessment Of Dmsp Electron Temperatures In The Topside Ionosphere, Bradford S. Green Mar 2001

Validation And Assessment Of Dmsp Electron Temperatures In The Topside Ionosphere, Bradford S. Green

Theses and Dissertations

Geomagnetic disturbances in the near earth space environment can adversely affect numerous military and Department of Defense (DoD) systems and operations. To improve the prediction accuracy of such disturbances, the next generation of space environment forecast models aims to automatically ingest real-time ionospheric measurements. This research validates and assesses one such measurement - the Defense Military Satellite Program (DMSP) measured electron temperature (Te). DMSP Te data were validated against near simultaneous incoherent scatter radar (ISR) Te measurements from Millstone Hill, MA and Sondrestrom, Greenland between Winter 1996 and Summer 2000. Of the 37 Millstone and six …

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Cooperative Behavior Schemes For Improving The Effectiveness Of Autonomous Wide Area Search Munitions, Daniel P. Gillen Mar 2001

Cooperative Behavior Schemes For Improving The Effectiveness Of Autonomous Wide Area Search Munitions, Daniel P. Gillen

Theses and Dissertations

The problem being addressed is how to best find and engage an unknown number of targets in unknown locations using multiple autonomous wide area search munitions. In this research cooperative behavior is being investigated to improve the overall mission effectiveness. A simulation was used to emulate the behavior of autonomous wide area search munitions and measure their overall expected performance. This code was modified to incorporate the capability for cooperative engagement based on a parameterized decision rule. Using Design of Experiments and Response Surface Methodologies, the simulation was run to achieve optimal decision rule parameters for given scenarios and to …

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Modeling Pressurized Water Reactor Kinetics, William H. Harman Mar 2001

Modeling Pressurized Water Reactor Kinetics, William H. Harman

Theses and Dissertations

A computer model of a pressurized water reactor (PWR) was developed for use as a teaching tool in graduate level nuclear reactor courses. The development, based on the diffusion equation, includes the methodology for solving the steady state spatial dependence of the neutron power output in a homogeneous right circular cylinder unreflected PWR system. This includes a two dimensional one energy group model, a three dimensional one energy group model, and a three dimensional two energy group model. To solve the homogeneous diffusion equation, a method was developed to search for criticality of the reactor based on the geometry and …

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Use Of Quantum Mechanical Calculations To Investigate Small Silicon Carbide Clusters, Jean W. Henry Mar 2001

Use Of Quantum Mechanical Calculations To Investigate Small Silicon Carbide Clusters, Jean W. Henry

Theses and Dissertations

Density Functional Theory (DFT) method was employed to model silicon carbide small clusters. Comparing the DFT calculation results with experimental results that observed by using photoelectron spectroscopy (PES), DFT predicts the same structures that experiment observed. For electron affinity, DFT results are in good agreement with experimental results, the root mean square negative offset 0.1 eV found using medium size of basis set (cc-pVDZ+) calculation. DFT results for vibrational frequencies are in good agreement with experiment results; the root mean square error is 72.5 cm-1 wave number. 16 ground state structures of SimCn (m ≤ 4, …

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A Low Power Application-Specific Integrated Circuit (Asic) Implementation Of Wavelet Transform/Inverse Transform, Daniel N. Harvala Mar 2001

A Low Power Application-Specific Integrated Circuit (Asic) Implementation Of Wavelet Transform/Inverse Transform, Daniel N. Harvala

Theses and Dissertations

A unique ASIC was designed implementing the Haar Wavelet transform for image compression/decompression. ASIC operations include performing the Haar wavelet transform on a 512 by 512 square pixel image, preparing the image for transmission by quantizing and thresholding the transformed data, and performing the inverse Haar wavelet transform, returning the original image with only minor degradation. The ASIC is based on an existing four-chip FPGA implementation. Implementing the design using a dedicated ASIC enhances the speed, decreases chip count to a single die, and uses significantly less power compared to the FPGA implementation. A reduction of RAM accesses was realized …

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Control And Characterization Of Line-Addressable Micromirror Arrays, Harris J. Hall Mar 2001

Control And Characterization Of Line-Addressable Micromirror Arrays, Harris J. Hall

Theses and Dissertations

This research involved the design and implementation of a complete line-addressable control system for a 32x32 electrostatic piston-actuated micromirror array device. Line addressing reduces the number of control lines from N2 to 2N making it possible to design larger arrays and arrays with smaller element sizes. The system utilizes the electromechanical bi-stability of individual elements to bold arbitrary bi-stable phase patterns. The control system applies pulse width modulated (PWM) signals to the rows and columns of the micromirror array. Three modes of operation were conceived and built into the system. The first was the traditional signal scheme which requires …

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Development And Testing Of A Multiple Filter Approach For Precise Dgps Positioning And Carrier-Phase Ambiguity Resolution, Paul E. Henderson Mar 2001

Development And Testing Of A Multiple Filter Approach For Precise Dgps Positioning And Carrier-Phase Ambiguity Resolution, Paul E. Henderson

Theses and Dissertations

The most precise relative positioning obtained using differential GPS depends on accurately determining carrier-phase integer ambiguities. To achieve high precision, many current static and kinematic algorithms use a floating-point solution until enough information becomes available to fix the carrier-phase ambiguities accurately. A mew method is presented that uses a multiple model Kalman filter to resolve the carrier-phase integer ambiguities. This method starts with the floating-point results, yet smoothly and rapidly attains the precision of the correct fixed-integer solution, eliminating the need to decide when to switch from the floating to the fixed-integer solution. This method is based on a theoretically …

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Factors Influencing The Air Force Cycle Ergometry Fitness Assessment, Heather M. Hunn Mar 2001

Factors Influencing The Air Force Cycle Ergometry Fitness Assessment, Heather M. Hunn

Theses and Dissertations

This research investigated the influence of exercise activities, situational factors, and personality on the Air Force submaximal cycle ergometry test (SCET). Data were collected via a questionnaire administered to 209 active duty students and faculty assigned to the Air Force Institute of Technology during their required annual SCET. Stepwise multiple regression and ANOVA were used to find the proportion of variance explained by the significant predictors of SCET results for various subsets of the sampled population. For the group as a whole, self-reported test anxiety explained 24% of the variance in SCET results, while reported aerobic caloric expenditure during exercise …

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Multiple Model Adaptive Estimation For Time Series Analysis, Ibrahim Dulger Mar 2001

Multiple Model Adaptive Estimation For Time Series Analysis, Ibrahim Dulger

Theses and Dissertations

Multiple Model Adaptive Estimation (MMAE) is a Bayesian technique that applies a bank of Kalman filters to predict future observations. Each Kalman filter is based on a different set of parameters and hence produces different residuals. The likelihood of each Kalman filter's prediction is determined by a magnitude of the residuals. Since some researchers have obtained good forecasts using a single Kalman filter, we tested MMAE's ability to make time series predictions. Our Kalman filters have a dynamics model based on a Box-Jenkins Auto-Regressive Moving Average (ARMA) model and a measure model with additive noise. The time-series prediction is based …

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Turbine Blade Surface Roughness Effects On Shear Drag And Heat Transfer, Jess W. Drab Mar 2001

Turbine Blade Surface Roughness Effects On Shear Drag And Heat Transfer, Jess W. Drab

Theses and Dissertations

This work used scaled samples of actual turbine blade surfaces to characterize correlations between turbine surface roughness, friction coefficient, and convective heat transfer rate-parameters which affect an engine's efficiency and the blade's lifespan. For erosion/deposits, friction coefficients up to 250 times higher and convective heat transfer coefficients of up to 150 times higher were found when compared to a flat plate baseline. Other roughness types (pitting and fuel deposits) yielded less dramatic results. These results did not follow existing friction coefficient-to-heat transfer coefficient correlations, such as the Reynolds analogy. While these analytical and empirical correlations hold for flat plates, they …

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A System Dynamics Approach To Modeling Temperature Effects In Solid Waste, David A. Jokinen Mar 2001

A System Dynamics Approach To Modeling Temperature Effects In Solid Waste, David A. Jokinen

Theses and Dissertations

The amount of municipal solid waste discarded to landfills is continually increasing even with extensive recycling efforts. The need to understand the behavior of waste in landfills is increased due to the decreasing number of active landfills, communities' concern to the potential hazards associated with landfills, and companies or installations with landfills on-site need to understand landfill behavior comply with new legislation concerning design and detecting hazardous material movement of-site. This research is focused on increasing the understanding of landfill behavior by examining the effects of temperature in a landfill system. A system dynamics approach was used in this research …

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Dissolution Of Chromium From Inhalable Primer Paint Particles Into A Simulated Lung Fluid, David A. Kauth Mar 2001

Dissolution Of Chromium From Inhalable Primer Paint Particles Into A Simulated Lung Fluid, David A. Kauth

Theses and Dissertations

The use of chromate as a corrosion inhibitor in primer paint is an essential component for the protection of aluminum-skinned aircraft and the primary source of hexavalent chromium (Cr (VI)) exposure to USAF aircraft painters. The objective of this research was to quantify the dissolution of chromate from freshly sprayed paint particles into a simulated lung fluid (SLF). Two primer paints were sprayed with a paint spray gun to generate overspray particles for collection into impingers filled with SLF. Particles were allowed to soak in SLF for 24 and 48 hours and then the particles were removed by centrifugation. The …

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A Traffic Pattern-Based Comparison Of Bulk Image Request Response Times For A Virtual Distributed Laboratory, David B. Hooten Mar 2001

A Traffic Pattern-Based Comparison Of Bulk Image Request Response Times For A Virtual Distributed Laboratory, David B. Hooten

Theses and Dissertations

Various agencies throughout the Department of Defense possess intelligence imagery and electrooptical signature data required by researchers in the field of automatic target recognition (ATR). The Air Force Research Laboratory, Sensors Directorate, as been tasked with creating a virtual distributed laboratory (VDL) which will make this data available to ATR researchers via high speed networks such as the defense research and engineering network (DREN). For this research, a model for simulating potential operational network configurations and collaboration scenarios was developed and implemented using OPNET. The results of the simulations were analyzed using statistical methods to determine the impact on performance …

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Weapon System Environmental Life Cycle Cost Methodologies And Models, William H. Kale Iii Mar 2001

Weapon System Environmental Life Cycle Cost Methodologies And Models, William H. Kale Iii

Theses and Dissertations

Major Defense Acquisition Programs (MDAP) cost billions of dollars and have 30 to 50 year life spans. Numerous (federal, state, etc.) laws, Environmental Protection Agency regulations, and Executive Orders have driven DoD to develop and implement significant environmental policies within the past ten to fifteen years. Congressional mandate now requires each MDAP to evaluate its environmental life cycle cost (ELCC) to minimize these costs. This research focuses on the current methodologies and models used to predict and calculate the ELCC of a MDAP. This thesis analyzed the difficulties associated with using ELCC methodologies and models and examined several case studies …

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Validation And Characterization Of Ionospheric Densities Measured By Dmsp, Herbert L. Keyser Mar 2001

Validation And Characterization Of Ionospheric Densities Measured By Dmsp, Herbert L. Keyser

Theses and Dissertations

Future models of the thermosphere-ionosphere-magnetosphere system will require near real-time assimilation of ionospheric parameters to specify% and forecast these regions One of the current sensors that will be used in the GAIM model is the DMSP SSIES. Knowledge of the SSIES's reliability and data characteristics is key to using the data when relying on automated processes to ingest the data. To validate the DMSP value, the DMSP-measured density is compared to ground-based ISR measurements from solar minimum to solar maximum. The DMSP data are compared to data from the ISRs located at the Millstone Hill Observatory in Massachusetts and Sondrestrom …

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Prediction Of Pilot Induced Oscillations (Pio) Due To Activator Rate Limiting Using The Open-Loop Onset Point (Olop) Criterion, Gregory P. Gilbreath Mar 2001

Prediction Of Pilot Induced Oscillations (Pio) Due To Activator Rate Limiting Using The Open-Loop Onset Point (Olop) Criterion, Gregory P. Gilbreath

Theses and Dissertations

Rate limiting has been a causal or contributing factor for Pilot Induced Oscillations (PIO). As part of the joint Air Force Institute of Technology/Test Pilot School (AFIT/TPS) program, an examination of the Open-Loop Onset Point (OLOP) criterion, developed by DLR German Aerospace, was conducted to see if it could predict PIO due to rate limiting and to evaluate its potential as a design tool. The criterion was applied to three previous flight test programs involving rate limiting. Findings from this analysis led to the HAVE OLOP flight test which was flown on the NF-16D Variable Stability In-flight Simulator Test Aircraft …

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An Objective Evaluation Of Four Sar Image Segmentation Algorithms, Jason B. Gregga Mar 2001

An Objective Evaluation Of Four Sar Image Segmentation Algorithms, Jason B. Gregga

Theses and Dissertations

Because of the large number of SAR images the Air Force generates and the dwindling number of available human analysts, automated methods must be developed. A key step towards automated SAR image analysis is image segmentation. There are many segmentation algorithms, but they have not been tested on a common set of images, and there are no standard test methods. This thesis evaluates four SAR image segmentation algorithms by running them on a common set of data and objectively comparing them to each other and to human segmentors. This objective comparison uses a multi-metric a approach with a set of …

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Modification Of Position And Attitude Determination Of A Test Article Through Photogrammetry To Account For Structural Deformation, Sean A. Krolikowski Mar 2001

Modification Of Position And Attitude Determination Of A Test Article Through Photogrammetry To Account For Structural Deformation, Sean A. Krolikowski

Theses and Dissertations

This study improved the current method of position and attitude determination to account for structural deformation of the wind tunnel test article due to aerodynamic loading. To account for deformation, parabolic bending and linear twisting coefficients were added into the Levenberg-Marquardt multi-parameter solver. By accounting for deformation, the accuracy of position and attitude determination was greatly improved. This study also takes a qualitative look at the optimum number of wind tunnel cameras and model targets. Optimal configuration was found to be around 50 targets and 2 cameras offset by 90 degrees.

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Utility Of Experimental Design In Automatic Target Recognition Performance Evaluation, James M. Higdon Mar 2001

Utility Of Experimental Design In Automatic Target Recognition Performance Evaluation, James M. Higdon

Theses and Dissertations

This research investigates current practices in test and evaluation of classification algorithms, and recommends improvements. We scrutinize the evaluation of automatic target recognition algorithms and rationalize the potential for improvements in the accepted methodology. We propose improvements through the use of an experimental design approach to testing. We demonstrate the benefits of improvements by simulating algorithm performance data and using both methodologies to generate evaluation results. The simulated data is varied to test the sensitivity of the benefits to a broad set of outcomes. The opportunities for improvement are threefold. First, the current practice of 'one-at-a-time factor variation (only one …

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Modeling Biodegradation Of Chlorinated Groundwater Contaminants Under Iron-Reducing Conditions Of A Constructed Wetland: A System Dynamics Approach, Max E. Johnson Mar 2001

Modeling Biodegradation Of Chlorinated Groundwater Contaminants Under Iron-Reducing Conditions Of A Constructed Wetland: A System Dynamics Approach, Max E. Johnson

Theses and Dissertations

The purpose of this study is to determine and explore the fundamental processes associated with biodegradation of chlorinated ethenes in iron-reducing conditions of a constructed wetland and to evaluate the impacts of changing conditions (both natural and engineer-controlled) on the system. The modeler uses a system dynamics approach to construct a model that represents behavior in the iron-reducing environment. The model incorporates hematite, a form of oxidized iron (Fe3+), as the electron acceptor in microbial biodegradation in the system. Vinyl chloride, cis-dichloroethene, and trans-dichloroethene are known to anaerobically degrade to carbon dioxide in the presence of oxidized iron. …

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The Affect Of Varying Arousal Methods Upon Vigilance And Error Detection In An Automated Command And Control Environment, Brent T. Langhals Mar 2001

The Affect Of Varying Arousal Methods Upon Vigilance And Error Detection In An Automated Command And Control Environment, Brent T. Langhals

Theses and Dissertations

This study focused on improving vigilance performance through developing methods to arouse subjects to the possibility of errors in a data manipulation information warfare attack. The study suggests that by continuously applying arousal stimuli, subjects would retain initially high vigilance levels thereby avoiding the vigilance decrement phenomenon and improving error detection. The research focused on which methods were the most effective as well the impact of age upon the arousability of the subjects. Further the implications of vigilance and vigilance decrement for correct detections as well as productivity were explored. The study used a simulation experiment to provide a vigilance …

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Malicious Hackers: A Framework For Analysis And Case Study, Laura J. Kleen Mar 2001

Malicious Hackers: A Framework For Analysis And Case Study, Laura J. Kleen

Theses and Dissertations

Recent years have seen an increase in the number and severity of Information Operations (IO) attacks upon DoD resources. At a higher level, the US as a whole has come under cyber attack by individuals and groups seeking thrills, monetary gain, publicity for their causes, and myriad other goals. This effort develops a first cut model of individual hacker mentality that can be utilized to improve threat assessment, mitigate Information Assurance (IA) vulnerabilities, and improve risk assessment. Further, it is a first step toward automated characterization of Information Warfare (IW) attacks based upon hacker types. All hackers are not the …

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Attenuation And Refraction Of An Electromagnetic Wave In An Electron Beam Generated Plasma, Nathaniel P. Lockwood Mar 2001

Attenuation And Refraction Of An Electromagnetic Wave In An Electron Beam Generated Plasma, Nathaniel P. Lockwood

Theses and Dissertations

Artificially generated plasmas may be employed to alter the propagation characteristics of electromagnetic waves. The purpose of this report is to study the propagation of electromagnetic waves in an electron beam generated plasma. To understand the physics related to this concept requires the development of computational tools dealing with a plasma created by an electron beam, an assessment of the temporal and spatial evolution of the plasma, and a characterization of the refraction and attenuation of electromagnetic (EM) waves in a collisional plasma. Three computer programs were developed to characterize the effectiveness of an electron beam generated plasma in refracting …

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Requirements-Based Methodology For Determining Age Inventory Levels, James A. Mackenna Mar 2001

Requirements-Based Methodology For Determining Age Inventory Levels, James A. Mackenna

Theses and Dissertations

The purpose of this research was to illuminate crucial areas in analyzing AGE needs on an operational flightllne and assist in determination of AGE inventory levels. Further refinements could result in more objective and accurate assessments of actual flightline AGE needs and associated risks involved with reduction of AGE inventory levels. The research in this thesis consists of a discrete event simulation to determine desired AGE inventory level through an analysis of aircraft launches and wait time for AGE support by varying AGE (mean time between failure) MTBF and AGE inventory. Stochastic inputs for aircraft failures, AGE delivery times, and …

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A Methodology For Simulating The Joint Strike Fighter's Prognostics And Health Management System, Michael E. Malley Mar 2001

A Methodology For Simulating The Joint Strike Fighter's Prognostics And Health Management System, Michael E. Malley

Theses and Dissertations

The Autonomic Logistics System Simulation (ALSim) model was developed to provide decision makers a tool to make informed decisions regarding the Joint Strike Fighter's (JSF) Autonomic Logistics System (ALS). The ALS provides real-time maintenance information to ground maintenance crews, supply depots, and air planners to efficiently manage the availability of JSF aircraft. This thesis effort focuses on developing a methodology to model the Prognostics and Health Management (PHM) component of ALS. The PHM component of JSF monitors the aircraft status. To develop a PHM methodology to use in ALSim a neural network approach is used. Notional JSF prognostic signals were …

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Redundant Wavelet-Based Image Restoration Using A Prior Information, Mary K. Marcum Mar 2001

Redundant Wavelet-Based Image Restoration Using A Prior Information, Mary K. Marcum

Theses and Dissertations

Reconnaissance missions and satellites collect hundreds of images loaded with valuable information to be utilized by the Air Force. Intelligence operations must analyze these images to extract the information needed to help commanders make important decisions. No matter how obtained, images of this type are often degraded by noise due to disruptions such as atmospheric disturbances, optical system variations, motion, and large distance from the sensor to the source. This noise must be removed effectively to improve the quality of these images and ensure that the information contained in them can be correctly extracted. The Air Force relies on the …

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The Effect Of Improving The Logistics Pipeline On Supply Support Of Aerospace Expeditionary Forces, Steven L. Martinez Mar 2001

The Effect Of Improving The Logistics Pipeline On Supply Support Of Aerospace Expeditionary Forces, Steven L. Martinez

Theses and Dissertations

One of the biggest considerations for an Aerospace Expeditionary Force (AEF), in terms of cost and airlift requirement, is the use of aircraft spares kits to support combat operations. To date, these kits are built on the assumption that there would be no resupply for the first 30 days of a contingency. However, with more efficient transportation and information resources available today, it seems logical that resupply would occur much more quickly. If so, the Air Force should be able to trim its wartime stocks of aircraft spares. This thesis investigated the effect of improving the logistics pipeline on the …

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Lifecycle Energy And Air Emission Differences Between Electric And Internal Combustion Vehicles, David L. Mccleese Mar 2001

Lifecycle Energy And Air Emission Differences Between Electric And Internal Combustion Vehicles, David L. Mccleese

Theses and Dissertations

The U.S. Federal Government has encouraged shifting from internal combustion engine vehicles (ICEVs) to electric vehicles (EVs) with three objectives, reducing foreign oil dependence, greenhouse gas emissions, and criteria pollutant emissions. This thesis uses Monte Carlo simulation to predict lifecycle emissions and energy consumption differences per kilometer driven from replacing ICEVs with three EV options: lead acid, nickel cadmium (Ni-Cd), and nickel metal hydride (NiMH). All three EV options reduce U.S. foreign oil dependence by shifting to domestic coal. The probabilities that lifecycle energy consumption per km driven improve are lead acid 76%, Ni-Cd 64%, and NiMH 90%. The probabilities …

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Wavelet-Based Audio Embedding & Audio/Video Compression, Michael J. Mendenhall Mar 2001

Wavelet-Based Audio Embedding & Audio/Video Compression, Michael J. Mendenhall

Theses and Dissertations

With the decline in military spending, the United States relies heavily on state side support. Communications has never been more important. High-quality audio and video capabilities are a must. Watermarking, traditionally used for copyright protection, is used in a new and exciting way. An efficient wavelet-based watermarking technique embeds audio information into a video signal. Several highly effective compression techniques are applied to compress the resulting audio/video signal in an embedded fashion. This wavelet-based compression algorithm incorporates bit plane coding, first difference coding, and Huffman coding. To demonstrate the potential of this audio embedding audio/video compression system, an audio signal …

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Pilot Mental Workload Calibration, Jeremy B. Noel Mar 2001

Pilot Mental Workload Calibration, Jeremy B. Noel

Theses and Dissertations

Predicting high pilot mental workload is important to the U.S. Air Force because lives and aircraft can be lost when errors are made during periods of mental overload and task saturation. Current research efforts use psychophysiological measures such as electroencephalography, cardiac, ocular, and respiration measures in an attempt to identify and predict mental workload levels. The primary focus of this effort is the development of a calibration scheme that allows a small subset of salient psychophysiological features developed using actual flight data for one pilot on a given day to accurately classify pilot mental workload for a separate pilot on …

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