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Enhanced Animation Of Parallel Algorithms, Michael D. Lack Dec 1991

Enhanced Animation Of Parallel Algorithms, Michael D. Lack

Theses and Dissertations

Algorithm animation is a visualization method used to enhance understanding of the functioning of an algorithm or program. Visualization is used for many purposes, including education, algorithm research, performance analysis, and program debugging. This research, which follows from previous work, examines algorithm animation requirements for the various visualization purposes and extends the capabilities of an existing facilities, the AFIT algorithm Animation Research Facility (AAARF). The structure of AAARF is summarised and its visualization capabilities presented, analysed and compared with other similar packages. This research focuses on the parallel data requirements of the AAARF users, and the meaningful display of large …

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Graph-Based Visualization Of Formal Specification And Domain Specific Languages, Randel K. Langloss Dec 1991

Graph-Based Visualization Of Formal Specification And Domain Specific Languages, Randel K. Langloss

Theses and Dissertations

This research develops and implements Visual Refine, a graph-based visualization system, for the Refine wide-spectrum formal specification language and environment developed and marketed by Reasoning Systems, Inc. Refine specifications are represented in the Refine object base as abstract syntax trees (AST). Using these AST representations, one-to-one mappings are defined between nodes of the AST and the graphical icons of Visual Refine. Visual Refine uses these mappings to implement a set of formal transformations. Each transformation is encapsulated within a Refine rule, and this set of rules form the Visual Refine transformation system. The Visual Refine transformation system, in conjunction with …

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Improved Task Scheduling For Parallel Simulations, Andrew E. Mcnear Dec 1991

Improved Task Scheduling For Parallel Simulations, Andrew E. Mcnear

Theses and Dissertations

The objective of this investigation is to design, analyze, and validate the generation of optimal schedules for simulation systems. Improved performance in simulation execution times can greatly improve the return rate of information provided by such simulations resulting in reduced development costs of future computer/electronic systems. Optimal schedule generation of precedence-constrained task systems including iterative feedback systems such as VHDL or war gaming simulations for execution on a parallel computer is known to be N P-hard. Efficiently parallelizing such problems takes full advantage of present computer technology to achieve a significant reduction in the search times required. Unfortunately, the extreme …

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A Spatially Partitioned Parallel Simulation Of Colliding Objects, Robert S. Moser Dec 1991

A Spatially Partitioned Parallel Simulation Of Colliding Objects, Robert S. Moser

Theses and Dissertations

This study investigated the application of a conservative synchronization paradigm to the classical, distributed pool balls simulation executed on an eight node, Intel iPSC/2 hypercube. Wieland's concept of spatial partitioning and limited data replication was used. Analysis has shown that 100% parallelization of execution is possible in a conservative environment via assignment of multiple sectors to nodes. Two conservative formulations for minimum safe time were derived. A tradeoff exists between scalability and efficiency. Optimum sectoring prediction has been shown possible through application of linear regression techniques. The results of this research reveal that a conservative approach to distributed, discrete event …

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Speech Recognition Using Multiple Features And Multiple Recognizers, Thomas F. Rathbun Dec 1991

Speech Recognition Using Multiple Features And Multiple Recognizers, Thomas F. Rathbun

Theses and Dissertations

The purpose of this thesis is to demonstrate the feasibility of using multiple features and multiple recognizers to perform isolated word recognition. This is accomplished by performing multiple independent recognition tests and fusing the results together to get a single recognition result. The speech data is recorded and each word is extracted into a separate file. Eight features are calculated for each word. The features are calculated on 512 sample time slices and produce 16 component vector output. The three recognizers use the eight features to produce a total of 24 error distance lists. These lists are then fused together …

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Three-Dimensional Medical Image Registration Using A Patient Space Correlation Technique, Patrick J. Rizzuto Jr. Dec 1991

Three-Dimensional Medical Image Registration Using A Patient Space Correlation Technique, Patrick J. Rizzuto Jr.

Theses and Dissertations

The routine clinical use of three-dimensional data provided by modern medical imaging procedures is often impeded by the difficulty in accurately correlating the resultant volume datasets. These data are frequently obtained at different times using the same modality, or images of the same patient are sometimes produced using more than one imaging modality. In order to analyze the similarities and differences between such images, it is necessary for the medical imaging data to be spatially aligned using a process known as image registration. This research investigated a structure-based image registration technique based upon simple, three-dimensional relationships among user identified landmarks. …

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Design Of Style-V — A Translator To Convert Standard Vhdl Into A Stylized Form For Automated Microcode Generation, Dennis A. Rumbley Dec 1991

Design Of Style-V — A Translator To Convert Standard Vhdl Into A Stylized Form For Automated Microcode Generation, Dennis A. Rumbley

Theses and Dissertations

This thesis provides an analysis and preliminary design of Style V, a source-to-source computer language translator. Style-V converts IEEE standard VHDL into a special style of VHDL defined for a commercial tool, the Integrated Design Automation System (IDAS). Thirteen mappings between standard VHDL and the IDAS subset were identified. The mappings were analyzed using Domain Analysis and Modern Structured Analysis techniques. Four processes covering several of the mappings were completely analyzed. One mapping to convert CASE statements to IF statements was implemented. Since the IDAS restricts designs to bit logic, a method for representing multilevel logic with bit logic was …

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Effect Of Spatial Locality Prefetching On Structural Locality, Dirk D. Schalch Dec 1991

Effect Of Spatial Locality Prefetching On Structural Locality, Dirk D. Schalch

Theses and Dissertations

The purpose of this research was to analyze the effect that spatial locality prefetching in cache memory has on the structural locality of program memory referencing behavior. To examine this, a software simulator was built to model a proposed two-level cache memory subsystem. The proposed subsystem was designed to use spatial locality prefetching to exploit the structural locality contained in executing computer workloads. New memory referencing models were developed to incorporate the combined use of structural locality and spatial locality prefetching. From these models, equations were derived to predict the hit rates for both caches. Combined with the state transition …

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An Application Of The Object-Oriented Paradigm To A Flight Simulator, Dennis J. Simpson Dec 1991

An Application Of The Object-Oriented Paradigm To A Flight Simulator, Dennis J. Simpson

Theses and Dissertations

This thesis describes the object-oriented software development techniques that were used to analyze, design and implement a flight simulator. The objective of this thesis was to present a comprehensive object-oriented software development methodology and show how it was used in constructing an actual application. An extensive review of current object-oriented practices is presented along with the methods that were used to take the flight simulator from analysis to design and through to implementation. The description of the methodology concentrates upon the design and implementation phases of the object-oriented software lifecycle. Examples from the design of the flight simulator demonstrate how …

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A Cache Design To Exploit Structural Locality, Curtis M. Winstead Dec 1991

A Cache Design To Exploit Structural Locality, Curtis M. Winstead

Theses and Dissertations

A design and VHDL implementation of a content-addressable memory (CAM) to exploit structural locality is the subject of this research. The concept of structural locality is that memory locations are referenced in the same order as they were previously referenced. Therefore, if memory locations that exhibit structural locality can be made available to the CPU (Center Processing Unit) through a fast data store, an increase in speed of the computer system can be realized. The CAM's purpose is to store memory references in the order they were used by the CPU and prefetch these locations to a smaller on- chip …

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Parallelizing Serial Code For A Distributed Processing Environment With An Application To High Frequency Electromagnetic Scattering, Paul R. Work Dec 1991

Parallelizing Serial Code For A Distributed Processing Environment With An Application To High Frequency Electromagnetic Scattering, Paul R. Work

Theses and Dissertations

This thesis investigates the parallelization of existing serial programs in computational electromagnetics for use in a parallel environment. Existing Algorithms for calculating the radar cross section of a object are covered, and a ray-tracing code is chosen for implementation on a parallel machine. Current parallel architectures are introduced and a suitable parallel machine is selected for the implementation of the chosen ray tracing algorithm. The standard techniques for the parallelization of serial code are discussed, including load balancing and decomposition considerations, and appropriate methods for the parallelization effort are selected. A load balancing algorithm is modified to increase the efficiency …

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Proportional Plus Integral Control Of Aircraft For Automated Maneuvering Formation Flight, John L. Dargan Dec 1991

Proportional Plus Integral Control Of Aircraft For Automated Maneuvering Formation Flight, John L. Dargan

Theses and Dissertations

In this study an automated formation control system for a lead and wing aircraft flight is developed. The proposed formation control system is capable of controlling like or dissimilar aircraft in maneuvering formation flight. Thus, two versions of the C-130 aircraft, the C-130A and the C-130B, are modelled. The C-130B has superior performance characteristics to that of the C- 130A. The wing aircraft continuously measures lead aircraft position with an ideal on-board relative position sensor, maneuvering to maintain relative position. External formation guidance is assumed to be released in a single data burst, consisting of formation geometry and nominal separation …

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Application Of Nonlinear Qft To Flight Control Design For High Angle Of Attack Maneuvers With Thrust Vectoring, Steven J. Rasmussen Dec 1991

Application Of Nonlinear Qft To Flight Control Design For High Angle Of Attack Maneuvers With Thrust Vectoring, Steven J. Rasmussen

Theses and Dissertations

Nonlinear Quantitative Feedback Theory (QFT) is applied to the design of an flight Control system (FCS) to control maneuvers of an agile aircraft. To do this, maneuvers are chosen that are desirable during within visual range combat. Plant transfer functions are developed through the use of system identification, using the input/output time histories of the maneuvers. During the system identification process the q sub ij(o) are found directly and are constrained to be minimum phase. After identifying the plants, the cascaded multiple-input multiple-output QFT technique is used to design the FCS. During the design of the FCS, stability boundaries are …

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Electrically Erasable Programmable Integrated Circuits For Replacement Of Obsolete Ttl Logic, Joseph V. Breen Dec 1991

Electrically Erasable Programmable Integrated Circuits For Replacement Of Obsolete Ttl Logic, Joseph V. Breen

Theses and Dissertations

Two microcircuits with electrically erasable programmable logic arrays, which use Fowler-Nordheim (F-N) tunneling for both programming and erasing, were designed to demonstrate the use of programmable logic for obsolete TTL logic replacement. Each microcircuit was fabricated in the Orbit 2-micron double-poly low noise analog CMOS process through MOSIS. Software to generate VHDL structural models from a pin list was developed and the logic of both designs was verified by simulation using the Zycad VHDL simulator. The first microcircuit included a simple programmable logic circuit and test cells that allowed measurement of the programming characteristics of the floating gate transistors. Test …

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A Rigorous Utd Analysis Of Electromagnetic Scattering From Resistive Strips And Resistive-Loaded Conducting Strips, Douglas H. Casanova Dec 1991

A Rigorous Utd Analysis Of Electromagnetic Scattering From Resistive Strips And Resistive-Loaded Conducting Strips, Douglas H. Casanova

Theses and Dissertations

This thesis investigates electromagnetic scattering from resistive strips and resistive-loaded conducting strips using a rigorous UTD formulation. The UTD diffraction coefficients are based on the Wiener-Hopf technique and Jones' method. Scattering predictions are performed for constant resistive strips, constant resistive-loaded conducting strips, tapered resistive strips, and tapered resistive-loaded conducting strips. All strip geometries have a total width of 4 lambda. Predictions are compared to method of moments (MM) and measurements to determine the validity of the UTD prediction. Overall, there is good agreement. For TMz polarization the only deviations that occur with MM are near edge-on when the degree of …

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Radar Scattering From Foamed Plastic Target Supports, Michael W. Chambers Dec 1991

Radar Scattering From Foamed Plastic Target Supports, Michael W. Chambers

Theses and Dissertations

This study investigates the scattering from foamed ranges to support all sizes of targets for radar cross section measurements. Two common foamed plastics, styrofoam and expanded bead polystyrene (EPS), are discussed. Two types of scattering are associated with foamed plastic, coherent and incoherent. The incoherent is normally the lowest, but has not been satisfactorily quantified. Coherent scattering is related to the shape of the target, and the emphasis of this study is on the coherent return. One goal was to predict the coherent RCS of an EPS column using the Uniform Theory of Diffraction (UTD). It was found that UTD …

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Application Of Silicon Micromachining To Thermal Dissipation Issues In Wafer Scale Integrated Circuits, Edward Cosnyka Dec 1991

Application Of Silicon Micromachining To Thermal Dissipation Issues In Wafer Scale Integrated Circuits, Edward Cosnyka

Theses and Dissertations

The purpose of this research effort was to investigate the feasibility of applying the silicon micromachining technique to thermal management as applied to integrated circuits and wafer scale integration techniques. Three silicon micromachined structures and an untextured reference wafer were compared as heat-dissipating surfaces. These four surfaces were realized using 3-inch diameter, single crystal silicon wafers. The following structures were micromachined in silicon wafers using wet chemical, anisotropic etching and photolithographic techniques: (1) randomly spaced and sized pyramids in (100)-oriented silicon, (2) deep vertical-wall grooves in (110)-oriented silicon, and (3) micro-fluid channels in (100)-oriented silicon. The heat- dissipating silicon wafers …

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Binaural Sound Localization Using Neural Networks, Rushby C. Craig Dec 1991

Binaural Sound Localization Using Neural Networks, Rushby C. Craig

Theses and Dissertations

The purpose of this study was to investigate the use of Artificial Neural Networks to localize sound sources from simulated, human binaural signals. Only sound sources originating from a circle on the horizontal plane were considered. Experiments were performed to examine the ability of the networks to localize using three-different feature sets. The feature sets used were: time-samples of the signals, mena Fast Fourier Transform magnitude and cross correlation data, and auto-correlation and cross correlation data. The two different types of sound source signals considered were tones and gaussian noise. The feature set which yielded the best results in terms …

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Robotic Tactile Sensors Fabricated From A Monolithic Silicon Integrated Circuit And A Piezoelectric Polyvinylidene Fluoride Thin Film, Craig S. Dyson Dec 1991

Robotic Tactile Sensors Fabricated From A Monolithic Silicon Integrated Circuit And A Piezoelectric Polyvinylidene Fluoride Thin Film, Craig S. Dyson

Theses and Dissertations

The purpose of this research effort was to design, fabricate, and test a tactile sensor system consisting of an external high impedance switch circuit, an external multiplexing circuit, and a tactile sensor IC. In order to accomplish this objective, a hardware design and selection process was implemented along with a logical test methodology. An external multiplexer circuit samples all of the array elements in 50 ms. The current prototype sensor has linearity spanning loads of 0.8 g to 135 g, a load resolution of 20 g, and a maximum bandwidth of 25 Hz. Using an elementary shape recognition algorithm the …

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A Time-Dependent Adaptive Filter For Cochannel Interference Reduction, Matthew H. Foster Dec 1991

A Time-Dependent Adaptive Filter For Cochannel Interference Reduction, Matthew H. Foster

Theses and Dissertations

This thesis presents a Time Dependent Adaptive Filter (TDAF) which exploits the cyclostationarity of digitally modulated communications signals and seeks to improve the Signal to Interference Ratio (SIR) and Signal to Noise Ratio (SNR) of such signals. The TDAF is embedded in a computer simulation of a simple communication system consisting of a data source, data formatter, pulse shaping filter, BPSK modulator, and demodulator. In the simulation the TDAF and a Time Independent Adaptive Filter (TIAF) attempt to extract the Signal of Interest (SOI) from noise or interference. the criteria of Mean Squared Error (MSE) is used as the primary …

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A Rigorous Uniform Diffraction Analysis Of The Electromagnetic Scattering From Impedance Edges And Junctions, Joseph C. Fortney Dec 1991

A Rigorous Uniform Diffraction Analysis Of The Electromagnetic Scattering From Impedance Edges And Junctions, Joseph C. Fortney

Theses and Dissertations

This paper investigates the scattering from impedance strips and impedance-loaded conducting strips. The impedance strips are analyzed using Senior's impedance half plane formulation. Once the primary diffraction from the impedance half plane is presented, it is used to develop multiple diffraction mechanisms on an impedance strip. The scattering from impedance-loaded strips are analyzed using Maliuzhinets' impedance wedge formulation. The primary diffraction mechanism from an impedance wedge is used to develop the multiple diffractions on an impedance double wedge. The multiple diffractions on both types of strips are developed using the Extended Spectral Ray Method. Sample calculations are made for impedance …

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Gabor Segmentation Of High Resolution Synthetic Aperture Radar Imagery, Michael A. Hazlett Dec 1991

Gabor Segmentation Of High Resolution Synthetic Aperture Radar Imagery, Michael A. Hazlett

Theses and Dissertations

This thesis investigates the use of Gabor filters and a radial basis function (RBF) network for segmentation of high resolution (1 foot by 1 foot) synthetic aperture radar (SAR) imagery. Processing involved correlation between the SAR imagery and Gabor functions. Two methods for selecting the optimal Gabor filters are presented. This research used complex Gabor functions and operated on single polarization HH complex data. Following the selection f the proper Gabor filters, correlation coefficients for each image were calculated and used as features for the RBF network. Provided are results demonstrating how Gabor processing and a RBF network provide image …

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Determination Of Bistatic Radar Clutter Power From Topographic Data, Clyde R. Heddings Dec 1991

Determination Of Bistatic Radar Clutter Power From Topographic Data, Clyde R. Heddings

Theses and Dissertations

The purpose of this research was to develop a procedure for estimating the average bistatic radar clutter power from a topographic map using rough surface scattering theory. First, the terrain in the radar target area was divided into sub regions having homogeneous characteristics. A joint Gaussian distribution for the surface heights was fitted from the information contained in the topographic map contour lines for each homogeneous area. From these distributions, the normalized radar cross section for each terrain area was determined. The clutter power for each range cell was then determined via a modified radar range equation. The procedure was …

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Wave Propagation In A Randomly Inhomogeneous Medium - A Study Of The Problem, Kyle Hunter Dec 1991

Wave Propagation In A Randomly Inhomogeneous Medium - A Study Of The Problem, Kyle Hunter

Theses and Dissertations

The problem of calculating the scintillation index of an atmospherically propagating spherical wave is examined. The fourth statistical moment of the complex field is obtained by using Feynman (path) integral techniques applied to the stochastic parabolic equation. The general trajectory of each Feynman integral is approximated by a truncated Fourier-sine series and the infinite-fold integration of the Feynman integral is reduced to a three-fold Riemann integral which is shown to match results derived under different assumptions. This thesis is highly tutorial.

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Kalman Filter Tracking Of A Reflective Target Using Forward Looking Infrared And Doppler Return Measurements, Theodore D. Herrera Dec 1991

Kalman Filter Tracking Of A Reflective Target Using Forward Looking Infrared And Doppler Return Measurements, Theodore D. Herrera

Theses and Dissertations

Plume phenomenology experiments conducted in 1990 uncovered the existence of plume speckle reflectance emanating from the exhaust of a solid- propellant rocket motor due to the presence of metallic particulates in the plume. This impeded attempts, that are dependent upon the speckle return of an actively illuminated target hardbody, to discern the plume/hardbody interface. This thesis investigates the feasibility of employing the Doppler return phenomenon in discerning the plume/hardbody interface and locating the hardbody center-of-mass. The potential of the Doppler phenomenon's utilization lies in the fact that the Doppler return frequency spectra of the plume and the hardbody respectively possess …

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Comparison Of Afitpac Versus Nos And A Packet Radio Network Design, Thomas A. Iannelli Dec 1991

Comparison Of Afitpac Versus Nos And A Packet Radio Network Design, Thomas A. Iannelli

Theses and Dissertations

This thesis encompasses two themes: (1) A comparison of the Network Operating System (NOS) software package, developed by Phil Karn and others, and AFITPAC, written by Marsh and Geier at the Air Force Institute of Technology. The comparison is based on the Air Force Logistics Command's requirements for the development of a Packet Radio Network program. The results of the comparison are a recommendation that use of the NOS package be pursued because it can meet all twelve of the requirements and compiles with five of the Military Standard Protocols. (2) The design of a personal computer Packet Radio Network …

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Characterizing The Sensitivity, Selectivity, And Reversibility Of The Metal-Doped Phthalocyanine Thin-Films Used With The Interdigitated Gate Electrode Field-Effect Transistor (Igefet) To Detect Organophosphorous Compounds And Nitrogen Dioxide, Clayton P. Howe Dec 1991

Characterizing The Sensitivity, Selectivity, And Reversibility Of The Metal-Doped Phthalocyanine Thin-Films Used With The Interdigitated Gate Electrode Field-Effect Transistor (Igefet) To Detect Organophosphorous Compounds And Nitrogen Dioxide, Clayton P. Howe

Theses and Dissertations

This study investigated the sensitivity, reversibility, and selectivity of the thin film coatings used on the interdigitated gate electrode field effect transistor (IGEFET) gas microsensor. These responses were quantified based on the dc resistance changes and frequency domain responses of the microsensor. The thin-film materials included: copper phthalocyanine (CuPc), nickel phthalocyanine (NiPc), and cobalt phthalocyanine (CoPc). The challenge gases included: diisopropyl methylphosphonate (DIMP), dimethyl methylphosphonate (DMMP), nitrogen dioxide, ammonia, and boron trifluoride. Tests of the CuPc thin-films and nitrogen dioxide challenges established the primary set of test parameters expected to maximize the selectivity, sensitivity, and reversibility of the thin-film coatings. …

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A Robust Digital Flight Control System For An Unmanned Research Vehicle Using Discrete Quantitative Feedback Theory, Donald J. Lacey Jr. Dec 1991

A Robust Digital Flight Control System For An Unmanned Research Vehicle Using Discrete Quantitative Feedback Theory, Donald J. Lacey Jr.

Theses and Dissertations

This thesis describes application of digital multiple-input multiple- output (MIMO) Quantitative Feedback Theory (QFT) technique to the design of a three axis rate controller for the Lambda Unmanned Research Vehicle. The resulting robust controller performs well throughout the flight envelope without gain scheduling. It results from research done at the Air Force Institute of Technology. The Lambda URV was designed by the Control Systems Development Branch of the Wright Laboratory at Wright-Patterson AFB, OH for flight testing aircraft control hardware and software. The flight control system is built using a small perturbation linear model developed from flight test data. The …

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An Investigation Of A Design For A Finite-Difference Time Domain (Fdtd) Hardware Accelerator, James R. Marek Dec 1991

An Investigation Of A Design For A Finite-Difference Time Domain (Fdtd) Hardware Accelerator, James R. Marek

Theses and Dissertations

This study investigated increasing the speed of Finite-Difference Time Domain (FDTD) cell calculations through a special purpose architecture using Very Large Scale Integration (VLSI). These FDTD cell equations model inhomogeneous, isotropic, lossy magnetic and dielectric materials. Special attention was given to simplicity and performance, using the fastest components generally available in AFIT VLSI programs, while attempting to minimize component count. A VHSIC Hardware Description Language simulation of the proposed chip established design feasibility and provided performance estimates: 350 ns to generate the first cell value, 200 ns thereafter (30 MFLOPS maximum double-precision). This study also implemented boundary conditions in hardware …

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Analysis Of Visual Illusions Using Multiresolution Wavelet Decomposition Based Models, John S. Laing Dec 1991

Analysis Of Visual Illusions Using Multiresolution Wavelet Decomposition Based Models, John S. Laing

Theses and Dissertations

This thesis provides alternatives to the explanation that spatial filtering is responsible for the perception of illusory contours in the Kanisza Triangle illusion. Specifically, we use a Multiresolution Wavelet Decomposition to divide an image into spatial-frequency bands that are used as inputs to three biologically motivated models. The thesis includes a brief tutorial of Wavelet theory and an in-depth explanation of our implementation of recently published algorithms for Multiresolution Wavelet Analysis. The first model is based on the saccadic movements of the human eye. It demonstrates the importance of the high spatial-frequency content of an image in the formulation of …

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