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Air Force Institute of Technology

Theses and Dissertations

2005

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Articles 1 - 30 of 58

Full-Text Articles in Physical Sciences and Mathematics

Using Prospect Theory To Investigate Decision-Making Bias Within An Information Security Context, Neil J. Schroeder Dec 2005

Using Prospect Theory To Investigate Decision-Making Bias Within An Information Security Context, Neil J. Schroeder

Theses and Dissertations

Information security is an issue that has increased in importance over the past decade. In this time both practitioner and academic circles have researched and developed practices and process to more effectively handle information security. Even with growth in these areas there has been little research conducted into how decision makers actually behave. This is problematic because decision makers in the Department of Defense have been observed exhibiting risk seeking behavior when making information security decisions that seemingly violate accepted norms. There are presently no models in the literature that provide sufficient insight into this phenomenon. This study used Prospect …

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Multiple Channel Laser Beam Combination And Phasing Using Stimulated Brillouin Scattering In Optical Fibers, Brent W. Grime Dec 2005

Multiple Channel Laser Beam Combination And Phasing Using Stimulated Brillouin Scattering In Optical Fibers, Brent W. Grime

Theses and Dissertations

Brightness scaling lasers using stimulated Brillouin scattering (SBS) in optical fibers is explored. A multiple-channel amplifier approach is used to increase the total power of a laser system while avoiding a significant burden on a single channel. The work explores two approaches utilizing both SBS beam cleanup and SBS piston error conjugation. A unique beam combiner that takes advantage of the SBS beam cleanup properties of a long, gradient-index multimode fiber was designed and tested. The beam combiner was developed to combine multiple-channel laser beams simultaneously with high input and output coupling efficiency. The design for the SBS beam combiner …

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The Application Of Category Theory And Analysis Of Receiver Operating Characteristics To Information Fusion, Steven N. Thorsen Dec 2005

The Application Of Category Theory And Analysis Of Receiver Operating Characteristics To Information Fusion, Steven N. Thorsen

Theses and Dissertations

Multisensor data fusion is presented in a rigorous mathematical format, with definitions consistent with the desires of the data fusion community. A model of event-state fusion is developed and described. Definitions of fusion rules and fusors are introduced, along with the functor categories of which they are objects. Defining fusors and competing fusion rules involves the use of an objective function of the researcher's choice. One such objective function, a functional on families of classification systems, and in particular, receiver operating characteristics (ROCs), is introduced. Its use as an objective function is demonstrated in that the argument that minimizes it …

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Early Warning And Prediction Of Internet Attacks And Exploits, Brian P. Zeitz Sep 2005

Early Warning And Prediction Of Internet Attacks And Exploits, Brian P. Zeitz

Theses and Dissertations

A safe, secure, and functional information network is vital in today’s Air Force net centric environment. Information is more critical today than it has ever been. As more operational functions are placed in cyber space and greater computing power becomes available to everyone, keeping these networks safe and secure is an almost unattainable task. Network security entails Intrusion Detection Security, but another form of security or “insecurity” is quickly gaining attention. Honeypots allow the black hat community to attack and penetrate non-production systems. By monitoring and studying these attacks, network defenders can develop better Information Assurance tactics, techniques and procedures …

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Operator State Estimation For Adaptive Aiding In Uninhabited Combat Air Vehicles, Christopher A. Russell Sep 2005

Operator State Estimation For Adaptive Aiding In Uninhabited Combat Air Vehicles, Christopher A. Russell

Theses and Dissertations

This research demonstrated the first closed-loop implementation of adaptive automation using operator functional state in an operationally relevant environment. In the Uninhabited Combat Air Vehicle (UCAV) environment, operators can become cognitively overloaded and their performance may decrease during mission critical events. This research demonstrates an unprecedented closed-loop system, one that adaptively aids UCAV operators based on their cognitive functional state A series of experiments were conducted to 1) determine the best classifiers for estimating operator functional state, 2) determine if physiological measures can be used to develop multiple cognitive models based on information processing demands and task type, 3) determine …

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Liquid Crystal On Silicon Non-Mechanical Steering Of A Laser Vibrometer System, Kevin S. Kuciapinski Sep 2005

Liquid Crystal On Silicon Non-Mechanical Steering Of A Laser Vibrometer System, Kevin S. Kuciapinski

Theses and Dissertations

This research examined the possibility of using a non-mechanical beam steering device to steer the beam of a coherent laser radar system. Non-mechanical beam steering devices offer many advantages in size, weight, power requirements, and steering speeds. Additionally, non-mechanical beam steering devices present the capabilities of splitting a single beam into multiple beams as well as beam forming and expanding. The coherent laser radar system used was a Laser Vibrometer System. The beam of the laser vibrometer was steered from 0 mrad to 3 mrad at 1 mrad increments using the liquid crystal on silicon (LCOS) device. The laser vibrometer …

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Fit-To-Fight: Waist Vs. Waist/Height Measurements To Determine An Individual's Fitness Level A Study In Statistical Regression And Analysis, Steven J. Swiderski Jun 2005

Fit-To-Fight: Waist Vs. Waist/Height Measurements To Determine An Individual's Fitness Level A Study In Statistical Regression And Analysis, Steven J. Swiderski

Theses and Dissertations

Air Force members are to be tested for fitness by measuring their abdominal circumference, counting the number of sit-ups and push-ups they can accomplish, and the time it takes them to run 1 and miles. The abdominal measurement is a "one-size-fits-all" fitness standard. This research determines that a person's waist-to-height ratio is a better measurement than the waist measurement to estimate an individual's fitness level. This research estimates that all of the variables used to proxy fitness (Gender, Age, Height, Waist Circumference, Waist-to-Height Ratio, Push-Ups, and Sit-Ups) are statistically significant and do represent good estimators of physical fitness. This research …

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The Navigation Potential Of Signals Of Opportunity-Based Time Difference Of Arrival Measurements, Kenneth A. Fisher Jun 2005

The Navigation Potential Of Signals Of Opportunity-Based Time Difference Of Arrival Measurements, Kenneth A. Fisher

Theses and Dissertations

This research introduces the concept of navigation potential, NP, to quantify the intrinsic ability to navigate using a given signal. NP theory is a new, information theory-like concept that provides a theoretical performance limit on estimating navigation parameters from a received signal that is modeled through a stochastic mapping of the transmitted signal and measurement noise. NP theory is applied to SOP-based TDOA systems in general as well as for the Gaussian case. Furthermore, the NP is found for a received signal consisting of the transmitted signal, multiple delayed and attenuated replicas of the transmitted signal, and measurement noise. Multipath-based …

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Explicit Building Block Multiobjective Evolutionary Computation: Methods And Applications, Richard O. Day Jun 2005

Explicit Building Block Multiobjective Evolutionary Computation: Methods And Applications, Richard O. Day

Theses and Dissertations

This dissertation presents principles, techniques, and performance of evolutionary computation optimization methods. Concentration is on concepts, design formulation, and prescription for multiobjective problem solving and explicit building block (BB) multiobjective evolutionary algorithms (MOEAs). Current state-of-the-art explicit BB MOEAs are addressed in the innovative design, execution, and testing of a new multiobjective explicit BB MOEA. Evolutionary computation concepts examined are algorithm convergence, population diversity and sizing, genotype and phenotype partitioning, archiving, BB concepts, parallel evolutionary algorithm (EA) models, robustness, visualization of evolutionary process, and performance in terms of effectiveness and efficiency. The main result of this research is the development of …

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The Analysis Of A Link Between A Remote Local Area Network And Its Server Resources, Theresa D. Beaver Jun 2005

The Analysis Of A Link Between A Remote Local Area Network And Its Server Resources, Theresa D. Beaver

Theses and Dissertations

As the Air Force transitions to an expeditionary force, the service's ability to provide computer capabilities at remote locations becomes more and more paramount. One way to provide this support is to create a Local Area Network (LAN) in which the workstations are positioned at the deployed location while the servers are maintained at a Main Operating Base (MOB). This saves the military money, because it eliminates the need to purchase and deploy server equipment as well as eliminating the need to deploy personnel to set-up and maintain the servers. There is, however, a tradeoff. As the number of personnel …

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A Framework For Routing And Topological Decision-Making Within A Transformational Communications Architecture, Alexander I. Smith Jun 2005

A Framework For Routing And Topological Decision-Making Within A Transformational Communications Architecture, Alexander I. Smith

Theses and Dissertations

A Transformational Communications Architecture (TCA) has been proposed by the US government with the goal of creating "an Internet in the sky." This thesis presents a framework which places user requirements at the heart of routing and topological decision-making within the TCA. It provides new terminology to describe data transmissions and link characteristics and an approach to formulating cost functions to better meet user needs. The framework is intended to stimulate interest and focus efforts on how to meet military specific requirements by taking advantage of the TCA's diverse capabilities and topology. Cost functions using newly-defined parameters are simulated and …

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Development Of A Defense Meteorological Satellite Program (Dmsp) F-15 Disturbance Storm-Time (Dst) Index, James M. Bono Mar 2005

Development Of A Defense Meteorological Satellite Program (Dmsp) F-15 Disturbance Storm-Time (Dst) Index, James M. Bono

Theses and Dissertations

As the DoD's use of space and space assets increases, so does its need for timely and accurate predictions of space weather conditions. A good understanding of the data from satellites together with data from ground stations can help model and determine variations in the space environment. An accurate, real-time Disturbance storm-time (Dst) index would be a primary input into current and future space weather models The Dst index is a measure of geomagnetic activity used to assess the severity of magnetic storms. The index is based on the average value of the horizontal component of the Earth's magnetic field …

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Deconvolution Analysis Of Laser Pulse Profiles From 3-D Ladar Temporal Returns, Michael D. Walter Mar 2005

Deconvolution Analysis Of Laser Pulse Profiles From 3-D Ladar Temporal Returns, Michael D. Walter

Theses and Dissertations

Three-dimensional laser imaging systems offer important advantages for battlefield applications, such as night-time targeting and tactical reconnaissance. Recently developed technologies used by coherent detection systems that collect temporally resolved images include arrays of Avalanche Photo-Diodes (APD), Geiger mode APDs, and photo-diodes. Frequently, LADAR systems produce waveforms from each detector that characterize the convolution of the transmitted laser pulse with the target surface. The pulse convolution generates uncertainty as to the precise location of a target surface, which can severely impact various weapon systems' targeting capability. This work analyzes two deconvolution techniques: Wiener filtering and an iterative process derived from the …

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A Sampling And Transformation Approach To Solving Random Differential Equations, Roger A. Erich Mar 2005

A Sampling And Transformation Approach To Solving Random Differential Equations, Roger A. Erich

Theses and Dissertations

This research explores an innovative sampling method used to conduct uncertainty analysis on a system with one random input. Given the distribution of the random input, X, we seek to find the distribution of the output random variable Y. When the functional form of the transformation Y=g(X) is not explicitly known, complicated procedures, such as stochastic projection or Monte Carlo simulation must be employed. The main focus of this research is determining the distribution of the random variable Y=g(X) where g(X) is the solution to an ordinary differential equation and X is a random parameter. Here, y=g(X) is approximated by …

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Steady State Stress In A Coated Infinite Half-Space Subjected To A Moving Load, Jason M. Cruthirds Mar 2005

Steady State Stress In A Coated Infinite Half-Space Subjected To A Moving Load, Jason M. Cruthirds

Theses and Dissertations

This research investigates the use of coatings to mitigate the stress distribution into an infinite half-space. High energy impact phenomenon at velocities exceeding the speed of sound is an important area of interest to the Air Force Research Laboratory. Holloman Air Force Base's High Speed Test Track sustains significant damage due to this phenomenon. In this thesis, the track system and coating are modeled analytically with equations of motion in terms of linear displacements. Coating thickness and material properties of epoxy or polymer laminates are investigated to understand their affect of stress distribution in the rail. An analytic solution is …

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In-Line Particulate Transport And Dispersion Modeling Using The Regional Atmospheric Modeling System (Rams), John W. Englert Mar 2005

In-Line Particulate Transport And Dispersion Modeling Using The Regional Atmospheric Modeling System (Rams), John W. Englert

Theses and Dissertations

There are a number of analytical and semi-empirical models that describe the behavior of particulate matter in the atmosphere. Many of these require modification for all types of weather, dry versus wet deposition, and overall effects can be quite non-linear. Rainfall (rate, drop size, etc.), snowfall (rate, flake size, etc.), humidity, pressure, temperature, and combination of these greatly affect particle settling and washout rates. To that end, a method for tracking released constituents using the Regional Atmospheric Modeling System (RAMS) microphysics package is developed by modifying one of the hydrometeor categories (hail) in the microphysics package. The RAMS microphysics package …

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Characterizing A Neutron Energy Spectrum Using A "Forward Edge" Neutron Time-Of-Flight Spectroscopy Technique, Jeffrey S. Spear Mar 2005

Characterizing A Neutron Energy Spectrum Using A "Forward Edge" Neutron Time-Of-Flight Spectroscopy Technique, Jeffrey S. Spear

Theses and Dissertations

A Fermi-style thermal neutron disc chopper was designed, constructed, and calibrated in conjunction with a boron-loaded organic scintillator for use in creating a forward edge neutron time-of-flight spectroscopy technique. The forward edge neutron time-of-flight spectroscopy technique inferred the characteristics of a neutron energy spectrum. The system analyzed the spectrum of a moderated and unmoderated PuBe source with the aid of a MATLAB code. Through the use of pulse shape analysis techniques and energy spectroscopy the thermal neutron capture event was identified and isolated. Data analysis provided positive feedback in the disc chopper's ability to partially attenuate higher energy neutrons in …

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Using Liquid Crystal Spatial Light Modulators For Closed Loop Tracking And Beam Steering With Phase Holography, Michael J. Perry Mar 2005

Using Liquid Crystal Spatial Light Modulators For Closed Loop Tracking And Beam Steering With Phase Holography, Michael J. Perry

Theses and Dissertations

Optical Phased Array (OPA) technology offers advantages in the reduction of size, weight, and power of optical steering devices. Nematic liquid crystal (LC) spatial light modulators (SLMs) have been studied as a potential candidate for building non-mechanical OPAs. They can steer a laser beam and split the beam into multiple beams. This thesis builds upon the prior research showing each split beam can be individually controlled, including variation in intensity. A closed loop tracking scenario shows the flexibility of the SLM by tracking and stabilizing an incoming beam. Results show that applying a phase grating to the SLM has limitations …

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Electrical Activation Studies Of Silicon Implanted AlXGa1-XN, Timothy W. Zens Mar 2005

Electrical Activation Studies Of Silicon Implanted AlXGa1-XN, Timothy W. Zens

Theses and Dissertations

Electrical activation studies of silicon implanted AlxGa1-xN grown on sapphire substrates were conducted as a function of ion dose, anneal temperature, and anneal time. Silicon ion doses of 1x1013, 5x1013, and 1x1014 cm-2 were implanted in AlxGa1-xN samples with aluminum mole fractions of 0.1 and 0.2 at an energy of 200 keV at room temperature. The samples were proximity cap annealed at temperatures from 1100 to 1350 ºC and anneal times of 20 to 40 minutes with a 500 Å thick AlN cap in a nitrogen environment. The Hall coefficient …

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Environmental Acoustic Transfer Functions And Filtering Acoustic Signals, Brandon P. Dias Mar 2005

Environmental Acoustic Transfer Functions And Filtering Acoustic Signals, Brandon P. Dias

Theses and Dissertations

Signal processing is the method of taking a given signal and extracting useful information, usually by a means of a transformation of some kind. Acoustic signals are functions of time in which the output is a pressure or a velocity potential response. An acoustic signal is affected by the environment in which it propagates, so one can attempt to remove the environmental effects to extract the useful information, in this case the original signal. This thesis will derive, in a mathematical framework, the process of filtering extraneous signals in a way that yields the original signal, and will then apply …

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Passwords: A Survey On Usage And Policy, Kurt W. Martinson Mar 2005

Passwords: A Survey On Usage And Policy, Kurt W. Martinson

Theses and Dissertations

Computer password use is on the rise. Passwords have become one of the primary authentication methods used today. It is because of their high use that organizations have started to place parameters on passwords. Are password restrictions a nuisance? What are some of the consequences that result as organizations place the burden of their computer security on passwords? This thesis analyzes the results of a survey instrument that was used to determine if individuals are using similar techniques or patterns when choosing or remembering their passwords. It also looks at how individuals feel about using passwords. In addition, the authors …

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Classification Of Battlespace Detonations From Temporally Resolved Mutli-Band Imagery And Mid-Infrared Spectra, Anthony N. Dills Mar 2005

Classification Of Battlespace Detonations From Temporally Resolved Mutli-Band Imagery And Mid-Infrared Spectra, Anthony N. Dills

Theses and Dissertations

The classification of battlespace detonations, specifically the determination of munitions type and size using temporal and spectral features, has been studied using near-infrared (NIR) and multi-color visible wavelength imagers. Key features from the time dependence of fireball size are identified for discriminating various types and sizes of detonation flashes. The five classes include three weights of trinitrotoluene (TNT) and two weights of an enhanced mixture, all of which are uncased and detonated with 10% C4. Using Fisher linear discriminant techniques, features are projected onto a line such that the projected points are maximally clustered for the different classes of detonations. …

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Deep Level Defects In Electron-Irradiated Aluminum Gallium Nitride Grown By Molecular Beam Epitaxy, Michael R. Hogsed Mar 2005

Deep Level Defects In Electron-Irradiated Aluminum Gallium Nitride Grown By Molecular Beam Epitaxy, Michael R. Hogsed

Theses and Dissertations

Aluminum gallium nitride (AlGaN)-based devices are attractive candidates for integration into future Air Force communication and sensor platforms, including those that must operate in harsh radiation environments. In this study, the electrical and optical properties of 1.0 MeV electron irradiated n-AlxGa1-xN are characterized for aluminum mole fraction x = 0.0 to 0.3 using deep level transient spectroscopy (DLTS), temperature-dependent Hall, and cathodoluminescence (CL) measurements. Following irradiation of the AlGaN, it is found that four different electron traps are created, having energy levels within 0.4 eV below the conduction band edge. Three of these traps correspond to …

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Noise Estimation In The Presence Of Bpsk Digital Burst Transmissions, Susan E. Bettison Mar 2005

Noise Estimation In The Presence Of Bpsk Digital Burst Transmissions, Susan E. Bettison

Theses and Dissertations

This research explores noise estimation techniques in an attempt to improve upon a previously developed digital burst transmission Binary Phase Shift Keyed (BPSK) demodulator. The demodulator success is dependent on the accuracy of the estimate of Power Spectral Density (PSD) of the unknown noise. Given a discrete time signal transformed into the frequency domain, the research seeks to determine if it is possible to effectively estimate the PSD of the unknown noise. The demodulator was developed using a new signal model for digital burst transmissions based on linear spectral subspace theory. Using this model and the redundancy properties of BPSK …

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Non-Adiabatic Energy Surfaces Of The B+H2 Systems, Lachlan T. Belcher Mar 2005

Non-Adiabatic Energy Surfaces Of The B+H2 Systems, Lachlan T. Belcher

Theses and Dissertations

In order to solve the dynamics of a system, the kinetic energy operator of the Hamiltonian must be diagonalized. Diagonalization requires rotation of the system into a non-adiabatic representation. This rotation is a coupling angle determined by the derivative coupling terms. Derivative coupling terms are calculated using Columbus and Brooklyn, software packages. Separation of internal dynamics characterized by Jacobi coordinates, and external dynamics characterized by a set of Euler angles and the center of mass position, requires a transformation from Cartesian coordinates to Jacobi coordinates required for subsequent dynamical calculations. Previous attempts to solve for non-adiabatic energy surfaces in this …

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Limitations In Time Resolved Photoluminescence Of Gallium Nitride Using A Streak Camera, Thomas R. Jost Mar 2005

Limitations In Time Resolved Photoluminescence Of Gallium Nitride Using A Streak Camera, Thomas R. Jost

Theses and Dissertations

Semiconductor performance is often characterized in terms of the rate at which its carrier recombination processes occur. Carrier recombination, including radiative, and Shockley-Read-Hall and Auger (both nonradiative), occurs at ultra-fast times in the picosecond or femtosecond regimes. A device which can measure both spectral data and temporal phenomena at this speed is the streak camera. The capability to do time-resolved spectroscopy of wide band gap semiconductors using a streak camera has been established at AFIT for the first time. Time resolved photoluminescence (TRPL) from samples of gallium nitride were measured at temperatures of 5 K over spectral bands of 36.6 …

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Computational Model Of One-Dimensional Dielectric Barrier Discharges, Krista G. Marchand Mar 2005

Computational Model Of One-Dimensional Dielectric Barrier Discharges, Krista G. Marchand

Theses and Dissertations

As theory lags experiment for dielectric barrier discharge flow control, two different computational methods are implemented to give further insight into characteristics of the dielectric barrier discharge (DBD). A one-dimensional fluid model of a surface-type dielectric barrier discharge is created using He as the background gas. This simple model, which only considers ionizing collisions and recombination in the electropositive gas, creates an important framework for future studies into the origin of experimentally observed flow-control effects of the DBD. The two methods employed in this study include the semi-implicit sequential algorithm and the fully implicit simultaneous algorithm. The first involves consecutive …

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Detection Of Bacillus Spores By Aptamer Selectivity Using Atomic Force Microscopy, Nina M. Houtkooper Mar 2005

Detection Of Bacillus Spores By Aptamer Selectivity Using Atomic Force Microscopy, Nina M. Houtkooper

Theses and Dissertations

The anthrax attack of Oct 2001 demonstrates the need for a rapid detector for spores of Bacillus anthracis (BA). Current technology requires cultures of BA to be grown for 24 hours. Using aptamers, a type of nucleic acid ligand selective for a target molecule, to select BA spores for measurement without culturing is a possible solution for quicker detection. An aptamer having a specially selected structure is expected to selectively bind to the surface of its target spore, separating it from other material. An atomic force microscopy (AFM) method was developed to test this selectivity. Aptamers having structure selected to …

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Modeling The Infrared Intensity Of A Large Commercial Aircraft, Ruben Martinez Mar 2005

Modeling The Infrared Intensity Of A Large Commercial Aircraft, Ruben Martinez

Theses and Dissertations

Measuring the infrared signature of large civilian aircraft has become increasingly important due to the proliferation of man-portable air defense systems (MANPADS) and the increasing threat of their use by terrorists. Because of the range of these shoulder-fired weapons, most aircraft flying over 20,000 feet are safe from the threat; however, aircraft taking-off or landing are extremely vulnerable. A radiometric model was developed to simulate a large commercial aircraft’s infrared intensity during these two critical phases of flight. The radiometric model was largely based on the dimensions of a Boeing 747-400 aircraft. It is capable of simulating elevation angles between …

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Optical Investigation Of Transition Metal Implanted Wide Band Gap Semiconductors, Brian P. Feller Mar 2005

Optical Investigation Of Transition Metal Implanted Wide Band Gap Semiconductors, Brian P. Feller

Theses and Dissertations

Thin films of GaN, Al0.1Ga0.9N, and ZnO were implanted with Cr, Mn, and nickel Ni to produce dilute magnetic semiconductors. Optical and magnetic techniques were used to evaluate crystal structure restoration and coercive field strength as a function of implant species and annealing temperature. Maximum crystal restoration was obtained for Al0.1Ga0.9N after annealing at 675 °C; for Cr implanted p-GaN after annealing at 750 °C; for Mn or Ni implanted p-GaN after annealing at 675 °C; for Cr implanted ZnO after annealing at 700 °C; for Mn implanted ZnO after annealing at …

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