Engineering Commons^™

A Comparison Of Two Microcomputer Continuous Simulation Languages, Amy Brannon Kirkland

Retrospective Theses and Dissertations

Until the early 1980s, most digital simulation models of reasonably complex systems required the use of a mainframe for a solution to be obtained in a timely manner. Recently, the declining prices of computer memory, operating systems, and modern hardware have supported the implementation of large simulation packages on smaller machines. Today, tremendous improvements in the performance of microcomputers have provided the simulationist with a completely personalized, less expensive computing environment. Operating within a microcomputer environment, the simulationist must choose a suitable computer language. Often, user familiarity dictates the selection of a language, while other factors such as ease of …

Some Reasons Why New Technologies Are Not Always Successful - Specifically Directed Toward Cim, Shuk Fong Lai

Retrospective Theses and Dissertations

To keep the competitive edge, many companies constantly implement new technologies. However, the implementation of these new technologies are not always successful. Why?

Problems with implementation of new technologies can be either technical or managerial. This paper presents research limited to management problems and suggests the necessary changes. It also outlines the important factors in the decision-making process and the criteria for a successful implementation of a Computer Integrated Manufacturing (CIM) system. Many experts believe that CIM is the ultimate solution to slow and reverse the decline of the U.S. global manufacturing market. However, some companies that have implemented CIM …

Laser Induced Darkening Semiconductor Dope Glasses, Jayant Malhotra

Retrospective Theses and Dissertations

No abstract provided.

A System For Measuring The Phase Difference Between Two Points Of A Propagating Laser Beam, Jefferson E. Odhner

Retrospective Theses and Dissertations

An optical system has been designed, analyzed, implemented, and calibrated which measures the phase difference between two points of a propagating laser beam. The system is a quadrature interferometer whose detector outputs are processed by a computer. This quadrature interferometer measures both the phase and amplitude variations between two points of a laser beam after the beam passes through turbulence . These measurements are in turn processed by a computer to isolate the phase variations from the amplitude variations. Further statistical analysis which can be performed on these phase variations should provide an understanding of the phase fluctuations of propagating …

Analysis Of Phase Noise In Phase Lock Loop, Diane Marie Pavik

Retrospective Theses and Dissertations

This research report presents an introduction into phase lock loops (PLL) with a major emphasis on calculating phase noise in frequency synthesizers. A PLL model that incorporates the major sources of noise is presented for the purpose of design analysis. The model can be used to analyze second and fifth order PLLs which allows the accurate calculation of phase noise as a function of independent variable design parameters. The stability of PLLs is also analyzed to show the effects of a marginally stable system on the resultant phase noise. Developing an accurate PLL model which accounts for the major sources …

A Study Of The Reaction Kinetics For The Thermal Oxidation Of Dilute N-Heptane Vapors In A Plug Flow Reactor, Steven Hunter Ramsey

Retrospective Theses and Dissertations

During August through October, 1986, experiments were conducted with the aim of devel oping kinetic relationships for the thermal oxi dation of dilute n-Heptane vapors in air using a Lindberg tube furnace reactor. This project was designed to be the first step in the ultimate goal of research ing the effe cts upon the combustion of dilute organic vapors when certain chemicals are added to the combustion stream. These chemicals are postulated to form free radicals and thus enhance the oxidation of organ i cs . Comparison of the kinetics before and after the addition of t he free radical …

Object-Oriented Development Techniques For Real-Time Software Systems: A Case Study, Thomas S. Seldenright

Retrospective Theses and Dissertations

Great improvements have been made in computer technology over the last forty years. Today, systems are being developed to solve complex problems that were previously thought to be out of the reach of computer solutions. Unfortunately, advances in software development techniques have been outpaced by the advances made in hardware development techniques. In recent years, effort has been made to formalize software development techniques suitable for real-time systems. This paper presents an object-oriented approach to realtime systems development. The object-oriented development approach is applied to a real-time case study problem. The case study involves controlling the speed of a toy …

Finite Element Analysis Of A Glass Fiber Inclusion, Jeffery R. Southland

Retrospective Theses and Dissertations

This analysis investigates the micromechanical behavior of a fiber-reinforced composite. Two realistic deviations from the typical set of simplifying assumptions are considered: nonhomogeneous matrix properties and imperfect fiber/matrix bonds. The stress effects due to a soft matrix interlayer at the fiber interface and the loss of a portion of the fiber/matrix interface bond are examined. The analysis is performed with the ANSYS finite element program. The effects of higher order shape functions and different mesh densities are studied. The final results are compared to a previous analysis performed at Florida Technological University (now University of Central Florida) which utilized a …

An Overview Of Machine Vision, Juan C. Telchi

Retrospective Theses and Dissertations

The objective of this paper is to examine new ideas and other useful information on the most recent advances in the robotic vision field. A visual system model was introduced and the basic components of this model were explained. The principal areas in robotic vision were researched. This included two dimension and three dimension vision sensors. Industrial applications and future developments of machine vision systems were addressed. A survey was done to summarize the vision system market and the robot market share worldwide.

The Feasibility Analysis Of Cooling A Residential Space Using An Underground Air Pipe Coupled With An Air Chimney, Nam Ky Trinh

Retrospective Theses and Dissertations

This study examines the thermal and economic feasibility of using an earth-cooled air system of residential space cooling. A residential building located in Orlando, Florida was modeled to determine the sensible cooling load for various design factors. A parametric study was conducted to determine the effects of the following: inside set temperature, infiltration rate, and overall heat transfer coefficient of the walls and roof. The inside set temperature had the greatest impact on the cooling energy load, followed by the infiltration rate and the overall heat transfer coefficient of the walls and roof.

Two load conditions were examined to determine …

Using Combined Integration Algorithms For Real-Time Simulation Of Continuous Systems, Larry Keith Harbor

Retrospective Theses and Dissertations

At many American colleges and universities, efforts to enhance the retention of a diverse group of students have become a priority. This study represents part of this effort at the University of Central Florida, a large public suburban state university in the South. Specifically, this investigation evaluated Pegasus '95 and the Academic Mentoring Program offered in the Summer and Fall Semesters of 1995 to specially-admitted students who fell short of regular admissions requirements. During the summer, Pegasus '95 provided testing, orientation, guided course work, study skills workshops, and mentoring, both individually and in the context of cohesive socialization groups of …

A Proposed System For Determination Of Percent Cloud Cover, Carol L. Emrich

Retrospective Theses and Dissertations

A method for determining percent cloud cover by taking two consecutive images using different color contrast filters, specifically a red filter and a blue filter, is described. This method (RF/BF estimate) involves dividing the "red" image by the "blue" image, pixel by pixel, and determining the percentage of pixels in the resultant image with intensity values of one. This is the percent cloud cover. The RF/BF estimate is based on the different effects of molecule and particle scattering of electromagnetic waves in the visible portion of the spectrum. These two types of scattering, Rayleigh and Mie scattering respectively, are described …

Multiple Signal Relative Entropy Spectral Estimation, David Martin Gregory

Retrospective Theses and Dissertations

Presented is a generalized derivation of the Tzannes et al. algorithm (1985) to accommodate multiple signals and also a new algorithm for implementing the Relative Entropy method for estimating the spectral densities of multisignal input data.

Chapter 2 presents several of the current methods of Relative Entropy spectral estimation which involve solving N non-linear equations simultaneously. Chapter 3 presents the multisignal derivation for the Tzannes et al. method and develops the new algorithm which solves for one unknown at a time in an iterative fashion.

The performance of this new method is compared with the Maximum Entropy and Minimum Relative …

The Time Slot Interchange In A Digital Central Office, Khalil George Al-Maalouf

Retrospective Theses and Dissertations

The invention of the telephone and the telegraph opened the door to worldwide corrmunications. Over the years, complex and versatile corrmunication systems have evolved involving many devices and technologies. Switching protocols between switching offices have been established in accordance with the nature of the machines and with the capabilities of the transmission medium and its environment. Switching systems are now stored program oriented, providing a more generalized and digitally oriented internal switching capability. This report will discuss the Time Slot Interchange ( TSI), an important component of the Digital Central Office (DCO). The operation of the send section and the …

Polar Spectrum Coding, Daniel Harris Chapman

Retrospective Theses and Dissertations

Polar Spectrum Coding is a novel speech coding algorithm for narrowband voice communications. A polar Fourier transform of the signal is computed, and the magnitude and phase of the speech spectrum is encoded for transmission. The correlation between frames of speech signals is exploited to minimize the transmission rate required for intelligible speech. At the receiver, the encoded words are decoded and the spectrum reconstructed. An inverse Fourier transform is performed, and the result is the reconstructed speech waveform. Polar Spectrum Coding theory is explained. The sensitivities of various parameters on performance are explored, and performance in the presence of …

Saw Draw: An Interactive Graphical Layout System For Surface Acoustic Wave Devices, Jeffrey Blair Abbott

Retrospective Theses and Dissertations

This thesis introduces a solution to the problem of time and memory space requirements associated with the manipulation/creation of solid state device layout. Through the use of a hierarchical organization of data and a tailored indexing technique, the software described here, referred to as Saw Draw, is capable of manipulating huge amounts of data in a short period of time. This program was written for surface acoustic wave (SAW) device layout but works for a broad range of devices to include semiconductors, microstrip and others.

Due to the large number of details which must be stored for each SAW structure, …

The Design Of A Dual Method Metal-Organic Chemical Vapor Deposition System, David B. Cox

Retrospective Theses and Dissertations

For the fabrication of semiconductor devices, solar cells, and infrared detectors, thin film deposition methods are required. Of the deposition methods currently available including MBE, LPE, and MOCVD; MOCVD is preferred due to its relatively low cost per wafer, versatility, and high wafer throughput. Requirements which must be considered in the design of a deposition system are discussed. An MOCVD system is designed such that MOCVD can be carried out by plasma enhanced deposition (PED) or low pressure metal-organic chemical vapor deposition (LPMOCVD). As a result of the inherent characteristics of the two methods, a wide range of operational temperatures …

Research And Applications Of Expert Systems In Military Training, Philip Irwin Green

Retrospective Theses and Dissertations

This report surveys recent research and applications of Expert Systems in the military training and simulation community. The report reviews twenty-one recent papers covering this subject. Each paper reviewed has been assigned a class which establishes the phase of development of the system or activities described. For each paper the abstract is given, followed by comments which summarize in more detail significant parameters of the activities reported. This is then followed by a listing of the specific Expert System "areas of interest" described in the paper.

Display Peripheral For A Flight Simulator Using A Three-Dimensional Computer-Controlled Motor Driven Model, Kenneth Randall Flowers

Retrospective Theses and Dissertations

The flight simulator display peripheral, described herein, provides the visual aide necessary for observation of effects due to operator responses for any aircraft simulator which prohibits the observers from occupying space within the cockpit of the simulator.

This display peripheral is provided by a three-dimensional, computer-controlled, motor-driven model which duplicates the angular movements generated by the aircraft simulator by moving a model aircraft mounted within a clear plastic ball.

The display utilizes a Motorola 68000 educational computer board to translate the three aircraft angles. pitch, yaw and roll received from the aircraft simulator via an RS-232C compatible serial asynchronous communication …

Lansim: A Simulation Package For Estimating Performance Characteristics Of A Class Of Local Area Networks, Gregory Charles Buchner

Retrospective Theses and Dissertations

ABSTRACT During recent years, the trends in computer resource organization have seen the replacement of the traditional mainframe computers and their timesharing terminals with individual desktop workstations. These workstations can offer more computational power than the mainframes of less than a decade ago. With this distribution of processing from the more traditional mainframe computer comes the need to share peripheral resources among these desktop workstations. These include items such as file systems, tape drives, printers, plotters, and graphics display devices. A common way to share these among the multi-computer environment is to provide a transparent gateway that allows each workstation …

Char: The Fire Investigators Aid The Implementation Of Expert System, Pamella M. Johnson

Retrospective Theses and Dissertations

The purpose of this research is to determine the applicability of expert systems to fire investigation. This will be accomplished by: a) using an expert systems building tool, b) extraction and organization of the knowledge base, c) application of the system to solve a real problem.

A New Method For Broadband Surface Acoustic Wave Diffraction Analysis, Jacqueline Hanvey Hines

Retrospective Theses and Dissertations

This thesis describes an innovative technique for determining the impulse response of a SAW device including the effects of diffraction on both isotropic and anisotropic substrates. The approach presented is unique in that it determines the point-to-point impulse response for the isotropic case using the two-dimensional wave equation, and utilizes a double integral reduction technique to determine the tap-to-tap response, thereby significantly reducing the complexity of the calculations involved. An extension is then made to describe the impulse response of two cascaded transducers of arbitrary geometry, along with some simplifying cases. Previous attempts to model diffraction effects generally utilized either …

Axisymmetric Wave Propagation In A Finite Linear Elastic Cylinder, Brian D. Johnson

Retrospective Theses and Dissertations

This work addresses the linear elastic analysis of axisymmetric wave propagation in a finite elastic cylinder. The waves are generated by the Fast Triaxial Device (FTRXD), which fails soil specimens at very rapid rates. The very short duration of the triaxial tests requires the consideration of wave phenomena in the analysis of the test results.

The soil specimens are modeled as linear elastic cylinders which are compressed in the axial direction. The resulting axisymmetric waves are analyzed with the wave equations which are cast in finite difference form, allowing the solution of displacements and stresses throughout the cylinder as a …

Uniformity Correction For A Scanned Long Wavelength Infrared Focal Plane Array, George C. Heinold

Retrospective Theses and Dissertations

This paper presents an alternative approach in providing uniformity correction for an infrared focal plane array by utilizing analog MOSFET circuitry. This technology is compatible with modern VLSI production and is capable of enhanced operation at cryogenic temperatures. The method presented here is a potential contribution to the growing list of special analog circuit configurations which may be incorporated for on-chip signal processing, inside the cryogenic dewar assembly. Electronic packaging of current thermal systems could be significantly reduced in size and weight by trading some of the cumbersome digital algorithms and complex post-processing circuitry for implementation in VLSI form.

The …

Geographic Information Systems: The Developer's Perspective, Johnn B. Henris

Retrospective Theses and Dissertations

Geographic information systems, which manage data describing the surface of the earth, are becoming increasingly popular. This research details the current state of the art of geographic data processing in terms of the needs of the geographic information system developer. The research focuses chiefly on the geographic data model--the basic building block of the geographic information system. The two most popular models, tessellation and vector, are studied in detail, as well as a number of hybrid data models.

In addition, geographic database management is discussed in terms of geographic data access and query processing. Finally, a pragmatic discussion of geographic …

Applications Of Lattice Filters To Quadrature Mirror Filter Banks, Gregory R. Jaspers

Retrospective Theses and Dissertations

Presented is a method for designing and implementing lattice filters to be used in Quadrature Mirror Filter (QMF) Banks. Quadrature Mirror Filter Banks find use in applications where a signal must be spilt into subbands operated on then reconstructed in the output. Because of their structure, lattice filters do this very well and allow perfect reconstruction, even when the lattice coefficients must be quantized. In this paper QMF's and Lattice Filters are derived and analyzed. Application of the lattice filter is presented along with a design program and example of its use to implement a QMF. The computer aided design …

Barium Borate In Parametric Oscillation And 1.54 Micron Generation, Mark Kerrigan

Retrospective Theses and Dissertations

As to date, there are several relatively new crystals that have been developed for nonlinear or "parametric" optical applications, including KTP, LAP, KNbO3, m=NA, and BaB204 (barium borate, or simply BBO). The latter crystal, BBO, and the use of BBo to achieve parametric oscillation around an eyesafe wavelength of 1.54 microns is the emphasis of this paper.

Unpublished material includes determining the optimum type of coupling and pump wavelength used when generating 1.54 μm eyesafe radiation based upon Poynting vector walk off, suscpetibilityies, and both signal angular and spectral acceptance widths. Poynting vector walk off curves for linearly polarized extraordinary …

Ada Real-Time Performance Benchmarks For Personal Computer Environments, Stephen L. Laroche

Retrospective Theses and Dissertations

A set of benchmarks were developed to test the real-time performance of Ada Personal Computer (PC) compilers. The benchmark set measures the overhead associated with various functions, including subprogram calls both from within and outside of packages ( including generic), dynamic allocation and deallocation of objects, exceptions, task activation/termination, task rendezvous, various time related functions, common arithmetic functions, and file I/0. The benchmark set also determines the type of memory deallocation supported, and determines whether fixed-interval or pre-emptive delay task scheduling is used. The different benchmarks are described along with an explanation of the testing methods for each benchmark. Two …

Three-Level Block Truncation Coding, Deborah Ann Lee

Retrospective Theses and Dissertations

Block Truncation Coding (BTC) techniques, to date, utilize a two-level image block code. This thesis presents and studies a new BTC method employing a three-level image coding technique. This new method is applied to actual image frames and compared with other well-known block truncation coding techniques.

The method separates an image into disjoint, rectangular regions of fixed size and finds the highest and lowest pixel values of each. Using these values, the image block pixel value range is calculated and divided into three equal sections. The individual image block pixels are then quantized according to the region into which their …

The Application Of Transfer Matrices In The Dynamic Analysis Of Planar Elastic Mechanisms, Richard Kent Lindenberg

Retrospective Theses and Dissertations

Transfer matrices are used in the dynamic analysis of planar elastic mechanisms. Mechanism motion is discretized by dividing the motion into a finite number of intervals over which the mechanism is considered to be an instantaneous structure with constant geometry. Transfer matrix methods are then used to calculate the natural frequencies and corresponding mode shapes of the instantaneous structure. A transfer matrix relating the continuous, non-zero components of the state vector across a pin joint is developed. An elastic four bar mechanism and a crank slider mechanism with a rigid crank and elastic connecting rod are analyzed using lumped mass …