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An Object-Oriented Computer Aided Design Program For Modern Control Systems Analysis, Frederick L. Trevino
An Object-Oriented Computer Aided Design Program For Modern Control Systems Analysis, Frederick L. Trevino
Theses and Dissertations
This investigation is a continuation of the ICECAP-PC research project conducted under Prof. Gary B. Lamont at the Air Force Institute of Technology. It is an ongoing development of a public domain Computer Aided Design (CAD) package for Control Engineering students and faculty, with a special emphasis on education. This investigation focuses on three areas. First, an object-oriented environment is specified, designed and implemented. The functional structure of ICECAP-PC is then converted into an object-oriented structure because object-orientation provides an advanced logic and implementation structure and effectively addresses common software engineering issues. Additionally, a new interface featuring pull-down menus, mouse …
Detection Of Spoofing, Jamming, Or Failure Of A Global Positioning System (Gps), Juan R. Vasquez
Detection Of Spoofing, Jamming, Or Failure Of A Global Positioning System (Gps), Juan R. Vasquez
Theses and Dissertations
The Air Force has equipped its aircraft with avionic systems such as Global Positioning System (GPS) and Inertial Guidance Systems (INS) capable of providing accurate navigation solutions. The aircrews flying these aircraft require a system that can either survive the hostile environments encountered in combat or notify the aircrew that their performance has been significantly degraded. This research focuses on failure detection and isolation techniques using an extended Kalman filter and generalized likelihood ratios using matched filters. Analysis is conducted using a Kalman filter development package known as the Multimode Simulation for Optimal Filter Evaluation (MSOFE). Both a large order …
Signal Approximation With A Wavelet Neural Network, Charles M. Westphal
Signal Approximation With A Wavelet Neural Network, Charles M. Westphal
Theses and Dissertations
This study investigated the use of Wavelet Neural Networks (WNN) for signal approximation. The particular wavelet function used in this analysis consisted of a summation of sigmoidal functions (a sigmoidal wavelet). The sigmoidal wavelet has the advantage of being easily implemented in hardware via specialized electronic devices like the Intel Electronically Trainable Analog Neural Network (ETANN) chip. The WNN representation allows the determination of the number of hidden-layer nodes required to achieve a desired level of approximation accuracy. Results show that a bandlimited signal can be accurately approximated with a WNN trained with irregularly sampled data. Signal approximation, Wavelet neural …
Optical Haar Wavelet Transforms Using Computer Generated Holography, Peter G. Block
Optical Haar Wavelet Transforms Using Computer Generated Holography, Peter G. Block
Theses and Dissertations
This research introduces an optical implementation of the continuous wavelet transform to filter images. The wavelet transform is modeled as a correlation process and is implemented with a Vander Lugt correlator. The orthonormal basis set used is composed of two one-dimensional Haar functions and a two-dimensional Haar function. Each wavelet, as well as its first two dyadic scalings, is implemented with computer generated holography. The Interferogram method, which represents a function only in terms of its phase, is used to encode the wavelet functions. The results are imaged onto a CCD array and captured using a framegrabber. The optical results …
Real Image Visual Display System, James R. Brandt
Real Image Visual Display System, James R. Brandt
Theses and Dissertations
This thesis investigates a technique for improving the perception of three-dimensionality in images generated by a Silicon Graphics workstation. The technique involves using a spherical mirror into which the graphics from the CRT are projected. A real image of the graphic is formed by the mirror and it appears to be floating at the image plane. The three-dimensional effect is improved by adding reflections or shadows of the displayed object. Additionally, a method of using real objects with computer generated shadows and computer generated objects with real shadows is investigated. This is done in an effort to quantify how far …
The Effect Of An Adaptive Optical System's Spatio-Temporal Response On Imaging Performance, Patrick M. Harrington
The Effect Of An Adaptive Optical System's Spatio-Temporal Response On Imaging Performance, Patrick M. Harrington
Theses and Dissertations
Ideally, an adaptive optical control system would have instantaneous temporal response and infinite spatial bandwidth. In real systems, the response time of the adaptive optical control system is limited by the integration time of the wave front sensor, the computational time of the control algorithm, and the actuator response time. Additionally, finite inter actuator spacing limits the deformable mirror's ability to reproduce spatial frequencies having a period less than twice this spacing. Although analyses general enough to account for both the temporal and spatial characteristics of the adaptive optical system exist, they are complex and require detailed information regarding the …
Object Tracking Through Adaptive Correlation, Dennis A. Montera
Object Tracking Through Adaptive Correlation, Dennis A. Montera
Theses and Dissertations
This paper discusses the use of a correlation based system to track, an object through a series of images based on templates derived from previous image frames. The ability to track is extended to sequences which include multiple objects of interest within the field of view. This is accomplishes by comparing the height and shape of the template autocorrelation to the peaks in the correlation of the template with the next scene. The result is to identify the region in the next scene which best matches the designated target. In addition to correlation plane postprocessing, an adaptive window is used …
A Two-Dimensional Particle Simulation Of Parallel Plate Radio-Frequency (Rf) Glow Discharges, Eric J. Bennett
A Two-Dimensional Particle Simulation Of Parallel Plate Radio-Frequency (Rf) Glow Discharges, Eric J. Bennett
Theses and Dissertations
A two-dimensional model of parallel plate RF glow discharges was developed to study discharge phenomena important in plasma assisted processing of materials. The particle-in-cell method is used to calculate the trajectories of computer particles under the influence of both self and applied fields. Monte Carlo methods using the null collision technique are used to model collisions between charged particles and neutral gas atoms. Results of computer experiments are presented with special emphasis placed on ion motion in the sheath regions. Experimental results show some qualitative agreement with one-dimensional model results. Further work required to gain quantitative agreement is outlined.
Phase Conjugation In Optical Fiber Via Stimulated Brillouin Scattering With Feedback From A Barium Titanate Crystal, Patrick R. Emmert
Phase Conjugation In Optical Fiber Via Stimulated Brillouin Scattering With Feedback From A Barium Titanate Crystal, Patrick R. Emmert
Theses and Dissertations
The goal of this thesis was to obtain phase conjugation in multi-mode optical fiber via stimulated Brillouin scattering (SBS) with the aid of a barium titanate crystal which formed a phase conjugate cavity for the Stokes beam. SBS was demonstrated but the SBS threshold was unaffected by the presence of the barium titanate crystal and no evidence for the presence of phase conjugation in the optical fiber was obtained.
Processability Of Polythiophene Thin Films By Ultraviolet Photo Bleaching, Derek D. Fletcher
Processability Of Polythiophene Thin Films By Ultraviolet Photo Bleaching, Derek D. Fletcher
Theses and Dissertations
Materials possessing strong ��(3) optical properties such as Polythiophene are sought for the production of optical switches. Polythiophene thin films produced by plasma enhanced CVD show a surface rms roughness of 10-15 angstroms over single square micron areas which is acceptable for wave guiding in the near IR. This research investigates permanently changing the optical properties of such a thin film by exposure to UV radiation (254 nm, 35 mW/cm2), known as photo bleaching, in hope of creating a refractive index boundary for use in total internal reflection. After 60 minutes exposure the refractive index shows …
Cathodoluminescence Spectroscopy Of Zinc Germanium Phosphide Zngep2, Michael R. Gregg
Cathodoluminescence Spectroscopy Of Zinc Germanium Phosphide Zngep2, Michael R. Gregg
Theses and Dissertations
Zinc Germanium Phosphide (ZnGeP2) is a nonlinear semiconductor suitable for use as a laser tuning element over the two to six micron wavelength range. Although this crystal has been studied in the past, its luminescent properties are not yet well understood. In this present study, ZnGeP2 has been examined using cathodoluminescence spectroscopy (CL). Specifically, the spectral dependence of the CL was obtained as a function of electron beam energy, beam current and temperature. The resulting CL was found to be polarized with a peak structure that was dependent on the polarization. This peak structure observed by CL …
The Effect Of Oxide Layers And Boron Doping On The Breakdown Of High Purity Silicon, Brian A. Hibbeln
The Effect Of Oxide Layers And Boron Doping On The Breakdown Of High Purity Silicon, Brian A. Hibbeln
Theses and Dissertations
For many applications such as lasers and radar drive circuits, there exists a need for solid state high voltage, high current switches. Current gaseous discharge switches fail to satisfy the ruggedness, reliability, and lifetime requirements of today's systems. A promising alternative is the Photoconductive Semiconductor Switch (PCSS). The limiting factor in the operation of these switches is the occurrence of breakdown through channels formed slightly below the surface. A theory on the formation of these channels is presented based upon band bending at the metal-semiconductor interface, a nonhomogeneous space charge due to irregular trap distributions, and thermal runaway in localized …
Cation Production And Reactions Induced By Electron Impact On Tetraethoxysilane, Jeremy C. Holtgrave
Cation Production And Reactions Induced By Electron Impact On Tetraethoxysilane, Jeremy C. Holtgrave
Theses and Dissertations
The production of cations by electron impact on tetraethoxysilane (TEOS) is studied with a Fourier Transform mass spectrometer (FTMS). The operating principles of FTMS are reviewed and the experimental approach to the mass calibration and cross-section measurement is discussed. The cross-sections for total and partial ionization of Si(OC2H5)4 from threshold to 50 eV are measured. Also, the ion chemistry resulting from interactions between ions and neutral TEOS is examined.
Laser Phase Front Measurements Using A Phase Conjugate Twyman-Green Interferometer, William J. Mandeville
Laser Phase Front Measurements Using A Phase Conjugate Twyman-Green Interferometer, William J. Mandeville
Theses and Dissertations
This study demonstrated the use of a phase conjugate TwymanGreen interferometer for measuring the phase fronts of beams emitted by infrared diode lasers operating at 830 nm. This interferometer successfully measured the phase front of a single element diode laser, providing better resolution than its conventional counterpart. The phase conjugate mirror compensated for aberrations introduced by imperfect optics in the phase conjugating arm of the interferometer. This interferometer was unable to measure the phase front of a diode array due to the array's inability to create a phase conjugate return. The array's short coherence length is believed to be the …
Total Hemispherical Emittance Of Niobium-1% Zirconium Fuel Cladding For The Sp-100 Space Reactor, John E. Thomason Iii
Total Hemispherical Emittance Of Niobium-1% Zirconium Fuel Cladding For The Sp-100 Space Reactor, John E. Thomason Iii
Theses and Dissertations
Total hemispherical emittance was measured for the SP-100 reactor fuel cladding alloy (Nb-l% Zr). Based on a standard test method (ASTM C 835-82), experiments were conducted on a reference sample of oxidized stainless steel and then on a sample of actual cladding. The sample is heated in a vacuum by passing DC current through it until reaching equilibrium. Measurements are made of the electrical power dissipated in the sample and of the surface temperature. Using the Stefan-Boltzmann Law and some key assumptions concerning conductive and radiative heat transfer, the measured quantities are used to calculate emittance. Calculated values for unoxidized …
An Interactive Life Cycle Cost Forecasting Tool, Nicolas M. Habash
An Interactive Life Cycle Cost Forecasting Tool, Nicolas M. Habash
Theses and Dissertations
This thesis is about computing life cycle cost and culminates with a life cycle cost forecasting tool (software). The software is written in FORTRAN 77 and uses IMSL subroutine extensively for random number generation from various distributions. The algorithm can compute life cycle cost for the following types of cost elements: constant, stochastic, and cost estimating relationships (CERs). The use of a trapezoid approximation of payment allocation is allowed. Percent allocation of payments is also allowed and is recommended where the trapezoid fails to correctly represent the payment schedule. The CER algorithm handles cost data that was estimated in base …
A Two-Stage Intercontinental Ballistic Missile (Icbm) Design Optimization Study And Life Cycle Cost Analysis, David P. Blanks, Douglas M. Bruce, Anthony M. Logue, Ralph A. Sandfry, Stephen J. Skotte, Michael L. Zywien
A Two-Stage Intercontinental Ballistic Missile (Icbm) Design Optimization Study And Life Cycle Cost Analysis, David P. Blanks, Douglas M. Bruce, Anthony M. Logue, Ralph A. Sandfry, Stephen J. Skotte, Michael L. Zywien
Theses and Dissertations
Realities of recent changes in the fiscal environment and the international domestic security structure have caused the strategic community to make some difficult decisions to preserve the capability of the current ICBM force. One of these decisions is to view Minuteman Ill as the centerpiece of the strategic force well into the next century. Extending the life of the 24-year- old Minuteman III system requires system solutions that provide required performance at an affordable life cycle cost. The intent of this study is to demonstrate the feasibility of designing a 2-stage ICBM to perform the Minuteman III mission. The main …
Integrated Blade Inspection System (Ibis) Upgrade Study, Tony J. Deliberato, Steven W. Perkins, Steven K. Saplin, John G. Snyder, Gregory J. Toussaint
Integrated Blade Inspection System (Ibis) Upgrade Study, Tony J. Deliberato, Steven W. Perkins, Steven K. Saplin, John G. Snyder, Gregory J. Toussaint
Theses and Dissertations
The purpose of this design study was to identify ways to improve the Integrated Blade Inspection System. The Air Force requires inspection of jet engine compressor and turbine blades to locate defects and prevent engine failure. The current inspection process uses fluorescent penetrant as an aid to identify cracked blades. A systems engineering design process was applied to evaluate the current inspection techniques and to develop alternative methods to satisfy the Air Force requirements. Three different inspection systems were developed and compared to the current process: manual, semi-automated, and fully automated inspection. This study made several noteworthy contributions: development of …
Spectral And Spatial Pattern Recognition In Digital Memory, John M. Amrine
Spectral And Spatial Pattern Recognition In Digital Memory, John M. Amrine
Theses and Dissertations
The main purpose of this research is to develop a model that can be used to solve combined spectral and spatial pattern recognition problems. The basis of my model is a multiobjective discrete programming model developed by Benabdullah and Wright (B and W). The model will be modified and then tested by solving a real world problem with SPOT multispectral imagery. Several improvements were added to the B and W model, namely standard border length accounting and control over which pixels are selected by the model. The model was also improved to process more than one channel of imagery at …
Analysis Of Kriging Applied To Resolution Enhancement Of Digital Satellite Imagery, David J. Blaufuss
Analysis Of Kriging Applied To Resolution Enhancement Of Digital Satellite Imagery, David J. Blaufuss
Theses and Dissertations
To aid the viewer in interpreting the information contained in an image, spatial resolution of the image can be increased. One way to increase the resolution is to improve the optics and sensors of the imaging system. Another is to process the data on the ground by computer. Enhancement techniques can be employed to alter the image and extract necessary data. Current techniques to manipulate and enlarge an image are nearest-neighbor, bilinear interpolation, and cubic convolution which can give greater clarity and readability. To satisfy the growing demand for quality (high-resolution) remotely sensed images, new techniques to enhance images need …
An Analysis Of Usspacecom's Space Surveillance Network (Ssn) Sensor Tasking Methodology, Jeff M. Berger, Joseph B. Moles, David G. Wisley
An Analysis Of Usspacecom's Space Surveillance Network (Ssn) Sensor Tasking Methodology, Jeff M. Berger, Joseph B. Moles, David G. Wisley
Theses and Dissertations
This study provides the basis for the development of a cost/benefit assessment model to determine the effects of alterations to the Space Surveillance Network (SSN) on orbital element (OE) set accuracy. It provides a review of current methods used by NORAD and the SSN to gather and process observations, an alternative to the current Gabbard classification method, and the development of a model to determine the effects of observation rate and correction interval on OE set accuracy. The proposed classification scheme is based on satellite J2 perturbations. Specifically, classes were established based on mean motion, eccentricity, and inclination Since J2 …
Analysis Of Whole-Sky Imager Data To Determine The Validity Of Pcflos Models, Richard W. Boltz, George R. Kather
Analysis Of Whole-Sky Imager Data To Determine The Validity Of Pcflos Models, Richard W. Boltz, George R. Kather
Theses and Dissertations
Models used to predict the probability of a cloud-free line-of-sight (PCFLOS) from the ground to space have existed since the 1960s. Unfortunately, an adequate data set has not been available to check the validity of these models until the deployment of the Whole-Sky Imager (WSI) system in 1989. Now that a three-year database has been collected from the WSI system, it is possible to validate, or refute, the existing models. This study investigates the most generally accepted models. Specifically, we investigate three questions: (1) Is the Lund and Shank-lin PCFLOS model assumption of azimuthal independence valid; (2) Does the Lund …
Analysis Of Titan Iv Launch Responsiveness, Michael T. Dunn
Analysis Of Titan Iv Launch Responsiveness, Michael T. Dunn
Theses and Dissertations
This research investigates the feasibility of developing responsive space systems through responsive launch operations with the Titan IV, the only expendable heavy-lift launch vehicle in the United States inventory. A definition for responsive launch has not been firmly established by Air Force Space Command for this launch vehicle. For benchmark purposes, this study uses the responsive launch definition contained in the proposal request for the Medium Launch Vehicle Ill: launch vehicle ignition within 60 days of mission need notification. Titan IV launch processing at Cape Canaveral Air Force Station (CCAFS), Florida currently requires in excess of six months, rendering Titan …
Comparison Of Artificial Neural Networks With A Conventional Heuristic Technique For Optimization Problems, Jeffrey S. Gruner
Comparison Of Artificial Neural Networks With A Conventional Heuristic Technique For Optimization Problems, Jeffrey S. Gruner
Theses and Dissertations
This research investigates the utility of the Hopfield and Kohonen artificial neural networks to the traveling salesman optimization problem. A third, non-neural-network technique (the Christofides Algorithm - a competitive, bounded-solution operations research technique) is also investigated for comparison to the artificial neural network solutions. An eight and forty-two city distribution are chosen for comparison of the solutions.
A Model Of Global Positioning System (Gps) Master Control Station (Mcs) Operations, David N. Koster
A Model Of Global Positioning System (Gps) Master Control Station (Mcs) Operations, David N. Koster
Theses and Dissertations
The United States Air Force's Navstar Global Positioning System (GPS) provides high-accuracy space-based navigation and time distribution to suitably- equipped military and civilian users. The system consists of earth-orbiting satellites and a world-wide network of ground stations. A single operational control center, the GPS Master Control Station (MCS) monitors, maintains, and commands the GPS satellite constellation. The on-going deployment of the complete satellite constellation and recent changes in the operational crew structure may invalidate previously used planning and management paradigms. There is currently no analytical method for predicting the impact of these and other environmental changes on system parameters and …
Recurrent Neural Networks For Radar Target Identification, Eric T. Kouba
Recurrent Neural Networks For Radar Target Identification, Eric T. Kouba
Theses and Dissertations
A real-time recurrent learning algorithm was applied to a five class radar target identification problem. The wideband radar was assumed to measure both kinematic (tracking information expressed as estimated aspect angles) and high range resolution data from a single, isolated aircraft. The aspect angles (azimuth and elevation) of the aircraft relative to the radar were assumed to be constantly chancing. This created temporal sequences of high range resolution radar signatures that changed as the aspect angles changed. These sequences were used as input features to a recurrent neural network for three radar target identification test cases. The first test case …
A Toposcopic Investigation Of Brain Electrical Activity Induced By Motion Sickness, Dwight A. Roblyer
A Toposcopic Investigation Of Brain Electrical Activity Induced By Motion Sickness, Dwight A. Roblyer
Theses and Dissertations
A toposcope was constructed as a new tool to study signal frequency and phase relationships in electroencephalogram (EEG) records collected while subjects were experiencing motion sickness. This new tool, named TOPOS, is a software-based, multi-featured version of Grey Walter and Harold Shipton's device which they first produced in the late 1940s. The TOPOS graphical display permits the study of instantaneous frequency relationships between the input channels and a reference signal of fixed or varying frequency. TOPOS adds a correlation grid to aid observers in detecting channel-to-reference correlation levels. Users can also vary several display parameters via menus to optimize the …
Locating An Imaging Radar In Canada For Identifying Spaceborne Objects, William G. Schick
Locating An Imaging Radar In Canada For Identifying Spaceborne Objects, William G. Schick
Theses and Dissertations
This research presents a study of the maximal coverage p-median facility location problem as applied to the location of an imaging radar in Canada for imaging spaceborne objects. The classical mathematical formulation of the maximal coverage p-median problem is converted into network-flow with side constraint formulations that are developed using a scaled down version of the imaging radar location problem. Two types of network-flow with side constraint formulations are developed: a network using side constraints that simulates the gains in a generalized network; and a network resembling a multi-commodity flow problem that uses side constraints to force flow along identical …
Retinal Modeling: Segmenting Motion From Spatio-Temporal Inputs Using Neural Networks, David E. Swanson
Retinal Modeling: Segmenting Motion From Spatio-Temporal Inputs Using Neural Networks, David E. Swanson
Theses and Dissertations
We applied two first-order, linear, time-varying, differential equations to the task of segmenting motion from sequences of images. The equations are modified Grossberg formulas for long-term and short-term memory models characterizing the neurotransmitter and cell-activity levels of a synapse and neuron. We described how a two layered, sensory, neural network can be built using the equations to simulate the amacrine neurons of the retina. The model is defined using adaptive input nodes (adaptive model) and is compared to a similar model without these nodes (O and G model). By replicating the basic amacrine neuron model to form both one- and …
Correlation Based Target Location And Identification, Richard A. Wenzel
Correlation Based Target Location And Identification, Richard A. Wenzel
Theses and Dissertations
Correlation was investigated as a technique for locating and identifying visible light terrain board images of tanks, airplanes, and trucks. A correlator was built which utilizes the Fast Fourier Transform. The 180 images in the image set were correlated in both the raw form and after pre-processing via energy normalization and local energy normalization. The correlation of the raw images led to development of quantitative and heuristic rules for possible inclusion in a rule based expert system. The correlation of the local energy normalized images resulted in a 100 percent target location rate and can be used as a baseline …