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Theses and Dissertations

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Articles 2701 - 2730 of 2733

Full-Text Articles in Computer Sciences

A Biologically-Inspired Neural Network Architecture For Image Processing, Laurence E. Lazofson Dec 1990

A Biologically-Inspired Neural Network Architecture For Image Processing, Laurence E. Lazofson

Theses and Dissertations

This thesis project included a literature survey of biological and artificial neural network research followed by development and testing of high- order and image recognition hierarchical neural network algorithms. Following training, performance testing of second-order and third-order networks yielded maximum accuracies comparable to those achieved by multilayer perceptron classifiers operating on test data sets. Several versions of an image classification algorithm were tested for learning performance using pixel data from forward-looking infrared (FLIR) images of tanks, trucks, target boards, and clutter. Employing the biologically-motivated Lambertization and contrast normalization of pixel windows, correlations with multiple Gabor function wavelets, and a 'phase …

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Optical Image Segmentation Using Wavelet Filtering Techniques, Christopher P. Veronin Dec 1990

Optical Image Segmentation Using Wavelet Filtering Techniques, Christopher P. Veronin

Theses and Dissertations

This research effort successfully implemented an automatic, optically based image segmentation scheme for locating potential targets in a cluttered FLIR image. Such a design is critical to achieve real-time segmentation and classification for machine vision applications. The segmentation scheme used in this research was based on texture discrimination and employs orientation specific, bandpass spatial filters as its main component. The orientation specific, bandpass spatial filters designed during this research include symmetrically located circular apertures implemented on heavy, black aluminum foil; cosine and sine Gabor filters implemented with detour-phase computer generated holography photoreduced onto glass slides; and symmetrically located circular apertures …

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Nonlinear Interferometry: Optical Image Addition/Subtraction And Novelty Filters, Gordon T. Hengst Dec 1990

Nonlinear Interferometry: Optical Image Addition/Subtraction And Novelty Filters, Gordon T. Hengst

Theses and Dissertations

This thesis investigated the performance characteristics of a beam fanning novelty filter and designed a switchable optical image adder/subtractor. The filter spatial resolution, contrast ratio, onset time, and velocity response were measured for both z-cut and 45 deg. cut BaTiO3 crystals in the beam fanning configuration. Experimental results show that the special 45 deg. cut crystal produces the best overall beam fanning novelty filter. In addition, switchable optical image subtraction and addition were demonstrated for the first time using a modified Michelson interferometer configured with a phase-conjugating mirror and an adjustable length leg. The system demonstrated addition and subtraction with …

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Detection Of High Altitude Aircraft Wake Vortices Using Infrared Doppler Lidar: An Assessment, Michael J. Estes Dec 1990

Detection Of High Altitude Aircraft Wake Vortices Using Infrared Doppler Lidar: An Assessment, Michael J. Estes

Theses and Dissertations

This thesis investigated the feasibility of air-to-air detection of high altitude aircraft wake vortices at long ranges using infrared Doppler lidar. The purpose of this technique is to detect otherwise stealthy aircraft. Three laser wavelengths were analyzed: 1.064, 2.091, and 9.115 microns. Analysis revealed that the spectral width of the return signal from an aircraft wake presented a good signature for detection. Based on the analysis, a minimum signal-to-noise ratio of 0 db was established. Detection performance was then analyzed using signal-to-noise ratio calculations for backscatter by ambient atmospheric aerosols, jet engine exhaust soot particles, and condensation trail ice particles. …

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A Compact Optical Associative Memory Using Dynamic Holographic Storage Media And Photorefractive Gain And Attenuation Elements, Thomas J. Burns Dec 1990

A Compact Optical Associative Memory Using Dynamic Holographic Storage Media And Photorefractive Gain And Attenuation Elements, Thomas J. Burns

Theses and Dissertations

This research effort implemented a compact optical associative memory architecture consisting of a Fabry-Perot Confocal Resonator (FPCR) optical processing environment, two dynamically reprogrammable Lithium Niobate volume holograms, and Barium Titanate gain and attenuation elements. The reduced physical dimensions of the compact optical processing environment make it more adaptable to military applications than previous associative memory designs. The FPCR employs Mangin mirrors designed to reduce spherical aberrations in off-axis rays. The orientation of the gain element's grating vector angle and the model used to predict the profile of the attenuation element were unique to this research effort. The object stored in …

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A Comparison Of Human-Computer Interfaces In Air Force Organizations, Michael G. Morris Dec 1990

A Comparison Of Human-Computer Interfaces In Air Force Organizations, Michael G. Morris

Theses and Dissertations

This thesis investigated differences in organizational efficiency and effectiveness for users of graphical user interfaces and text-based interfaces on personal computers in Air Forces offices. Areas of interest included amount of time required to learn the basic system, amount of time required to learn new application, users' ratings of user-friendliness, users' perceptions of the extent that their system help them perform in their job, the number of software packages used on the job by users of each system, user satisfaction, responsible authorities' ratings of quality of output, and the relationship between user job experience level and interface used on the …

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Use Of Grasp Force Focus Positioning To Enhance The Torque Resistance Capability Of Robotic Grasps, Stephen G. Edwards Dec 1990

Use Of Grasp Force Focus Positioning To Enhance The Torque Resistance Capability Of Robotic Grasps, Stephen G. Edwards

Theses and Dissertations

Three-point-contact grasps are unique in that the homogeneous solution for the contact forces always produces a grasp force focus. Careful positioning of this focus point in the grasp plane can help avoid two things; slipping at the contact points, and violation of joint torque limits. The focus placement method is explored theoretically by examining two types of grasps on cylinders; 1) fingertip grasps using three independently operated fingers, and 2) single-finger power grasps with one contact point on each of three links. Constraint maps are generated for various fingertip grasps in order to show how proper placement of the grasp …

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A Low-Cost Part-Task Flight Training System: An Application Of A Head Mounted Display, David A. Dahn Dec 1990

A Low-Cost Part-Task Flight Training System: An Application Of A Head Mounted Display, David A. Dahn

Theses and Dissertations

To investigate the feasibility of using head-mounted display(HMD) and Computer Image Generators(CIG) in a low cost part-task trainer, we created a prototype system. Our approach was to build a virtual world interface using a HMD to an existing flight simulator application. This allowed a CIG with only one graphics channel to drive the display. To investigate which class of computing platform was suitable for use as the CIG, a cooperative thesis effort was launched to host the simulator on a mini-computer and micro-computer platform. The appropriate CIG could then be determined through demonstration and comparison between the systems. A software …

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Determining Concurrency In Object-Oriented Design Of Real-Time Embedded Systems Using Ada, Kenneth D. Baum Dec 1990

Determining Concurrency In Object-Oriented Design Of Real-Time Embedded Systems Using Ada, Kenneth D. Baum

Theses and Dissertations

One of the characteristics of real-time systems is concurrency. Designers of real-time systems have traditionally determined system concurrency at implementation time using the facilities of a cyclic executive. With the advent of programming language constructs for specifying concurrency, determining concurrency at design time has become a possibility. Several design methods, all of which are extensions of either Structured Design or Jackson System Development, provide heuristics to help the designer make concurrency decisions. The object-oriented approach, however, has no corresponding heuristics to aid designers of real-time systems. The purpose of this thesis was to develop heuristics to help designers make concurrency …

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Real-Time Flight Simulation And The Head-Mounted Display - An Inexpensive Approach To Military Pilot Training, Philip A. Platt Dec 1990

Real-Time Flight Simulation And The Head-Mounted Display - An Inexpensive Approach To Military Pilot Training, Philip A. Platt

Theses and Dissertations

The integration of the low-cost head-mounted display (HMD), an inexpensive graphics workstation-based flight simulator, and a communications network was investigated to determine if the prototype of an inexpensive multi- aircraft Virtual Flight Simulator could be built. Previous research efforts have coupled HMD technology and flight simulation; however, the cost of these systems has been high. This thesis effort emphasized the use of joystick devices to emulate pilot control, the implementation of a fully enclosed virtual flight simulator, and the utilization of low-cost NTSC-based television technology to produce a prototype. The virtual flight simulator also contained a basic set of instruments …

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The Development Of A Graphical Notation For The Formal Specification Of Software, Gene A. Place Dec 1990

The Development Of A Graphical Notation For The Formal Specification Of Software, Gene A. Place

Theses and Dissertations

The program tranformations lifecycle model, proposed by Balzer in 1984, may hold the key to dramatic leap in software engineer productivity necessitated by the tremendous growth in the world's demand for software. This leap in productivity is made possible by the program transformation lifecycle's reliance on formal specifications rather than programs as the primary vehicle for the creation and maintenance of software systems. Because formal specifications are concerned only with system behaviors and not implementation details, formal specifications tend to present critical system characteristics much more concisely than programs. The major disadvantage of using formal specifications in a software development …

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Mapping An Object-Oriented Requirements Analysis To A Design Architecture That Supports Design And Component Reuse, Kelly L. Spicer Dec 1990

Mapping An Object-Oriented Requirements Analysis To A Design Architecture That Supports Design And Component Reuse, Kelly L. Spicer

Theses and Dissertations

Design reuse has more potential for increasing the productivity of software development and maintenance than do traditional approaches to software reuse that emphasize reuse of smaller components. Current software development methods do not promote design reuse. The literature contains limited documented research on the subject, but enough that some design reuse principles can be gleaned. Among these principles are that reusable designs should be applicable within some domain of application, have a consistent structure, provide a method for instantiating the design, avoid object nesting, and promote reuse of smaller components as well. A design mapping method from an object-oriented requirements …

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A Remote Visual Interface Tool For Simulation Control And Display, William J. Derouchey Dec 1990

A Remote Visual Interface Tool For Simulation Control And Display, William J. Derouchey

Theses and Dissertations

This thesis discusses the design and development of the Visual Interactive Simulation Interface Tool (VISIT). VISIT was designed to provide the graphical representation and user interface for a simulation that is running on another processor utilizing internet communications. The system provides support for various input devices to control the simulation display and environment. Simulation objects are displayed using either a three-dimensional wireframe representation or a Gouraud shaded representation. Viewer interaction to the simulation is provided by a collection of commands that allow the viewer to initialize, start, stop, abort, and restart the simulations. The viewer also has the ability to …

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An Empirical Evaluation Of Analytical Models For Parallel Relational Database Queries, Mark C. Denham Dec 1990

An Empirical Evaluation Of Analytical Models For Parallel Relational Database Queries, Mark C. Denham

Theses and Dissertations

This thesis documents the design and implementation of three parallel join algorithms to be used in the verification of analytical models developed by Kearns. Kearns developed a set of analytical models for a variety of relational database queries. These models serve as tools for the design of parallel relational database system. Each of Kearns' models is classified as either single step or multiple step. The single step models reflect queries that require only one operation while the multiple step models reflect queries that require multiple operations. Three parallel join algorithms were implemented based upon Kearns' models. Two are based upon …

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An Ada-Based Framework For An Idef0 Case Tool Using The X Window System, Jay-Evan J. Tevis Ii Dec 1990

An Ada-Based Framework For An Idef0 Case Tool Using The X Window System, Jay-Evan J. Tevis Ii

Theses and Dissertations

This thesis documents the design strategy, implementation methodology, testing, and evaluation used in developing an Ada-based framework for SAtool II using the X Window System. SAtool II is an IDEF0 graphical project editor and data dictionary editor. An Ada-Based Framework for an IDEF0 Case Tool Using the X Window System is the ICAM Definition Method Zero graphical notation language adopted by the U.S. Air Force to produce a function model of a manufacturing system or environment (23:1-1). The Air Force Institute of Technology is conducting on-going research in the use of IDEF0 in the requirements analysis phase …

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Access And Operator Methods For The Triton Nested Relational Database System, Tina M. Harvey Dec 1990

Access And Operator Methods For The Triton Nested Relational Database System, Tina M. Harvey

Theses and Dissertations

Unique database requirements in the realm of non-standard applications (such as computer-aided design (CAD), computer-aided software engineering(CASE), and office information systems (OIS) have driven the development of new data models and database systems based on these new models. In particular, the goal of these new database systems is to exploit the advantages of complex data models that are more efficient (in terms of time and space) than their relationship counterparts. This research effort describes the relational design and implementation of the Triton nested relational database system, a prototype system based on the nested relational data model. Triton is intended to …

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An Empirical Study Of Combining Communicating Processes In A Parallel Discrete Event Simulation, Ann K. Lee Dec 1990

An Empirical Study Of Combining Communicating Processes In A Parallel Discrete Event Simulation, Ann K. Lee

Theses and Dissertations

The primary goal of distributed discrete event simulations is to achieve speedup in simulation execution time by distributing the processing of the simulation over multiple processors. When partitioned for distribution in this fashion, simulations are typically partitioned such that there are more processes than processors. This thesis reviews existing methods for distributed discrete event simulations, and proposes general guidelines for efficient partitioning for a given communications topology based on empirical evidence. A performance analysis is conducted for two approaches to partitioning the system. The first method chosen is a mapping of multiple processes to a processor and the second approach …

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An Object Oriented Design And Implementation Of The Idef0 Essential Data Model Using Ada And An Ada Based Expert System, Terry L. Kitchen Dec 1990

An Object Oriented Design And Implementation Of The Idef0 Essential Data Model Using Ada And An Ada Based Expert System, Terry L. Kitchen

Theses and Dissertations

This thesis develops and implements an Ada based object oriented design (OOD) of the IDEF0 Essential Data Model called the Essential Subsystem, which includes an Ada based expert system for IDEF0 model syntax checking. IDEF0 is a graphic approach to system description development by SofTech, Inc. for the U.S. Air Force Program for Integrated Computer Aided Manufacturing (ICAM) and is a subset of the Structured Analysis (SA) language (30, 36). The IDEF0 Essential Data Model is an entity-relationship (E-R) model of the IDEF0 language and represents the fundamental (essential) information of an IDEF0 model. …

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Automatic Determination Of Recommended Test Combinations For Ada Compilers, James S. Marr Dec 1990

Automatic Determination Of Recommended Test Combinations For Ada Compilers, James S. Marr

Theses and Dissertations

Ada compilers are validated using the Ada Compiler Validation Capability (ACVC) test suit, containing over 4000 individual test programs. Each test program focuses, to the extent possible, on a single language feature. Despite the advantages of this atomic testing methodology, it is often the unexpected interactions between language features that result in compilation problems. This research investigated techniques to automatically identify recommended combinations of Ada language features for compiler testing. A prototype program was developed to analyze the Ada language grammar specification and generate a list of recommended of features to be tested. The output from this program will be …

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An Object-Oriented Military Simulation Baseline For Parallel Simulation Research, Robert J. Rizza Dec 1990

An Object-Oriented Military Simulation Baseline For Parallel Simulation Research, Robert J. Rizza

Theses and Dissertations

This thesis documents the design and implementation of a discrete event military simulation using a modular object-oriented design and the C programming language. The basis simulation is one of interacting objects. The objects move along a predetermined path until they encounter another object. Objects react to the encounter object according to the implemented algorithm. Object reaction options are fight, evade, or do nothing. In the code's current form it is generic enough to allow a user the flexibility of creating an infinite number of scenarios bounded in size by the hardware's memory capacity. The modularity of design will allow for …

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Computer Generated Holography As A Three-Dimensional Display Medium, Bryant L. Stuart Dec 1990

Computer Generated Holography As A Three-Dimensional Display Medium, Bryant L. Stuart

Theses and Dissertations

A process was developed to produce three dimensional images using computer generated holography (CGH). This process consisted of a series of steps that began with a geometric description of an object and concluded with a three dimensional holographic image being computed from a synthetic wavefront. The objects used in this series of steps (or CGH pipeline) were described geometrically as a collection of three dimensional points. The modular nature of the CGH pipeline provided a flexible platform from which to evaluate various object geometries, interference calculations algorithms, and interference pattern recording and reduction techniques. This system was implemented with general …

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A Hypermedia Implementation For Reusable Software Component Representation, Gary G. Worrall Dec 1990

A Hypermedia Implementation For Reusable Software Component Representation, Gary G. Worrall

Theses and Dissertations

This study investigated software component representation methods. Hypermedia was chosen as the implementation method to represent a collection of reusable software components. The hypermedia implementation organizes knowledge about the component collection into a web of small information chunks called frames. The set of software components was represented using a hybrid classification scheme composed of enumerated and faceted parts. The enumerated part enables the user to progress along a path in a taxonomic tree, narrowing the scope of eligible components. Each leaf node in this tree denotes a class of components, members of which are distinguished by their time and space …

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Using Error Detection And Correction Coding For A Turbulent Atmospheric Optical Communications Link, Mark A. Cloutier Dec 1990

Using Error Detection And Correction Coding For A Turbulent Atmospheric Optical Communications Link, Mark A. Cloutier

Theses and Dissertations

Probability of bit error (Pb) performance for a turbulent, atmospheric, optical, communications link with convolutional error detection and correction coding was investigated. The codes investigated were all rate 1/2 codes with constraint lengths ranging from 3 to 7. It was assumed that the coded data stream was sufficiently interleaved so that the turbulent channel could be considered memoryless. A theoretical bound on Pb, given by Viterbi for a memoryless channel, was used to plot curves of Pb versus the signal intensity of last transmitter. These curves were plotted for three different levels of atmospheric turbulence and three …

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Model-Based 3-D Recognition System Using Gabor Features And Neural Networks, Phung D. Le Dec 1990

Model-Based 3-D Recognition System Using Gabor Features And Neural Networks, Phung D. Le

Theses and Dissertations

A different approach to pattern recognition was attempted using Gabor features, artificial neural nets, and an image generator. The Gabor features and artificial neural nets are sound biological-based, and the image generator provides complete access to any view of an object. This thesis tested the idea that their integration could form a robust 3-D recognition system. The results of the research showed that the Gabor features together with a neural net were used successfully in classifying objects regardless of their positions, out-of- plane rotations, and to a lesser extent in-plane rotations. The Gabor features were obtained by correlating the image …

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A Whole Word And Number Reading Machine Based On Two Dimensional Low Frequency Fourier Transforms, Mark A. O'Hair Dec 1990

A Whole Word And Number Reading Machine Based On Two Dimensional Low Frequency Fourier Transforms, Mark A. O'Hair

Theses and Dissertations

The Fourier transform is investigated as a means for developing an optical reader capable of reading a large vocabulary without segmenting the image of a word into individual characters. The reader is capable of reading printed and cursive font styles, is scale invariant, and is substantially insensitive to noise. The image of a particular word is treated as a single symbol; the two dimensional low frequency Fourier coefficients (assuming n coefficients are calculated) define the word's location on an n dimensional hypersphere of unit radius. The distance between individual locations (words) categorizes similar and dissimilar words. The smaller the distance, …

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Introductory Dataperfect® Instruction, Frances Jenson Larsen Apr 1990

Introductory Dataperfect® Instruction, Frances Jenson Larsen

Theses and Dissertations

The project should be used in a beginning computer class. These units contain projects from simple to complex. The first instructional unit uses a database that comes with the DataPerfect® program. The students build and manipulate a small database. Reports are prepared, and finally the students design an original database. These instructional units are intended to be used in a high school classroom with the DataPerfect® computer program. DataPerfect® is a copyrighted program marketed by WordPerfect Corporation of Orem, Utah.

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Data Base Design For Research In Comparative Zapotec, Anita C. Bickford Dec 1989

Data Base Design For Research In Comparative Zapotec, Anita C. Bickford

Theses and Dissertations

This thesis explores the nature and content of a comparative data base for the Zapotec languages of Mexico that may be produced. Many questions are discussed: how to sub-divide and list the Zapotec languages and dialects; what data format will be most accessible to researchers as well as to field workers with data to add; computer software considerations (designing computational tools); how to handle non-cognates with shared meanings, non-overlap of glosses (i.e., one Zapotec gloss covers several Spanish words, or vice versa), semantic shifts and secondary meanings, and other problems such as special characters, free variation, elisions, etc.; whether to …

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Expert System For Interpreting An Organizational Climate Survey Supporting Guided Development, Thabet Birro Aug 1989

Expert System For Interpreting An Organizational Climate Survey Supporting Guided Development, Thabet Birro

Theses and Dissertations

This project has lead to the development of a prototype, diagnostic, rule-based expert system to analyze data gathered with an organizational climate survey conducted in high technology firms. The development process followed an investigative look at the field of expert systems. The project was implemented using Level5 shell (by Level 5 research Inc.) in PC/MS-DOS environment.

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A Generalized Information Structure To Be Used In A Human-Factors Knowledge Base, Bruce J. Wachlin Nov 1985

A Generalized Information Structure To Be Used In A Human-Factors Knowledge Base, Bruce J. Wachlin

Theses and Dissertations

The purpose of this thesis is to design a generalized information structure that can be used in a human-factors knowledge base. The information structure will take into account the human factors requirements and the hardware characteristics of the system. In this thesis the design and implementation of several prototype systems of a generalized information structure to be used in a human-factors knowledge base are presented.

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Designing A Relational Data Base For A Problem Solving Environment, Kathryn S. Dawson Jan 1985

Designing A Relational Data Base For A Problem Solving Environment, Kathryn S. Dawson

Theses and Dissertations

When choosing a system design in which to solve a recurring problem which depends on interrelated data a relational data base environment should be considered. The original problem can be solved through this design and by allowing users to view the data in the relational constructs the data can be easily used in numerous other applications. Theoretical support insures the design is sound avoiding inaccurate results. Independence between the logical and physical views of the data enables the data base administrator to adjust the physical data structures in order to optimize system performance without affecting existing user applications.

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