Engineering Commons^™

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 …

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, …

Dynamic Performance-Based Student Model For An Intelligent Simulation Training System, Jenifer M. Sargeant

Retrospective Theses and Dissertations

Student modeling has been the subject of research since the mid-1970's. A student model is an evolving description of what the student knows about the subject domain. Much of the previous research has concentrated on evaluating a student in performing cognitive tasks. The Intelligent Simulation Training System (ISTS) applies the techniques of Artificial Intelligence, Intelligent Tutoring Systems and Expert Systems to simulation-based training. The ISTS Student Model is unique in that it evaluates the student in performance-based tasks. It monitors and records the student's ability to maintain relationships between objects in space and time. The scope of this research was …

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 …

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 …

Numerical Analysis Of The Resonant States Of Quantum Wells And Superlattice Devices, Alan Gilbert Whittaker

Retrospective Theses and Dissertations

This thesis is concerned with the development of a numerical model to describe the resonant states associated with quantum well and superlattice devices. A numerical method is described where the time-independent Schrodinger equation is represented as a series of simultaneous algebraic equations using the finite-element method. The eigenvalues for these equations are then found using a Sturm sequence, and the eigenfunctions subsequently calculated using a reverse iteration method containing orthogonality constraints. Simulations of specific devices are presented and compared with experimental results and good correlation is observed.

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 …

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 …

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 …

Efficient Algorithms For The Fixed Charge Problem, Ahmad Abdulah Moreb

Retrospective Theses and Dissertations

The main thrust of this research is to develop four solution procedures for the Fixed Charge Problem. All are based on approximating the fixed charge component by strictly polygonal linear components. The first procedure uses the functions technique to approximate the fixed charge; then linear programming with the restricted-basisentry technique is used to arrive at the final solution. Although this method starts with an approximated version of the fixed charge component, it arrives at an exact value to the objective function without the need for re-evaluating the objective function. The other three solution procedures are based on approximating the fixed …

Optical Interferometric Formation Of Phased Array Antenna Footprint/, John E. Sherwood

Retrospective Theses and Dissertations

A 40 dB gain RF Low Noise Amplifier (LNA) matched to a photodiode input is designed using TOUCHSTONE (S-parameter based CAD software), built, and tested. The RF LNA formed the detector of a Mach-Zehnder interferometer constructed with single mode fiber, coupler, Gradient Index Rod Acousto-optic modulator (ADM) . (GRINROD) lenses, and an The ADM is used to frequency shift the optical frequency by 125 MHz, and the motion of a GRINROD lens is used to produce an optical phase shift that is recovered at the detector as an electrical phase shift by using heterodyne detection . Finite Hankel transforms are …

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.

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 …

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 …

Phase Noise Analysis And Basic Measuring Techniques, James A. Ferrell

Retrospective Theses and Dissertations

Oscillators are important elements of RF and microwave communications systems. The increased use of the electromagnetic spectrum requires the use of better and cleaner oscillators. Local oscillators in RF to IF converters play a big role in the overall performance of the receiver systems because phase noise in the local oscillator can drastically reduce the signal to noise ratio at the output of the receiver, especially if the converter is at the front end. Phase noise is the parameter used to describe oscillator stability. The analysis and basic measurement techniques of phase noise are performed in this report.

This research …

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 …

Boundary Layer On A Continuous Flat Plate In Parallel Flow With Similar And Non-Similar Boundary Conditions, Vaughn H.M. Faber

Retrospective Theses and Dissertations

This thesis is a computational analysis of the incompressible laminar boundary layer on a continuous moving surface. The skin friction and heat transfer variations on a moving plate with similar and non-similar (constant) mass transfer at the wall are obtained for 210 cases for the similar boundary solution and 60 cases for the non-similar solution.

Both cases were solved numerically using the fourth order Runge-Kutta algorithm. For the non-similarity case, the local non-similarity method as described by Sparrow, Quack and Boerner was used. The analysis shows that the shear stress for both the similar and non-similar cases is higher when …

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 …

Investigative Study Of The Reliability Of A Rotating Turbine Blade, William Stuart Beal

Retrospective Theses and Dissertations

-Turbine blading incidents are a concern to electrical utilities since they can result in power plant unavailability. The reliability of a particular turbine blade is investigated in this report to determine if it can be replaced with a more reliable blade design. The majority of incidents concerning this blade have been attributed to stall flutter vibration that has been the result of unit operation at low load levels with high back-pressures in the steam condenser. Stall flutter can be avoided by limiting back-pressure levels during low load operation and is thus not a concern here. Another potential cause of unreliability …

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 …

Design Of A Systolic Architecture To Implement Graphic Transforms, Aimee A. Murray

Retrospective Theses and Dissertations

The graphics generator hardware is an important component of flight-training simulators. The function of this hardware is to generate 3D perspective images at rates of 30 frames per second to produce realistic out-ofwindow scenes viewed by the crew under training. Within most graphics generator hardware are array processors which achieve high computation throughput necessary to generate real-time processing. The function of the array processors is to transform, clip, rotate and perspective project the data base into screen coordinates for use by the graphic generator. A FIMD (few instructions multiple data) systolic architecture is proposed to achieve high computational throughput that …

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 …

Development Of A Bi-Directional Inference Engine Using An Object-Oriented Approach, Taha A. Sidani

Retrospective Theses and Dissertations

An inference engine is the mechanism by which an expert system program uses the domain specific information in the knowledge base to solve a problem at hand. Most of the current systems apply one of three control strategies to perform the reasoning process. These strategies are better known as forward chaining, backward chaining, and hybrid control. However, some of these systems restrict the user by confining him/her to use only the type of control provided. Hybrid systems infer using both forward and backward chaining. In either case, the user is limited to the method in which the knowledge engineer represented …

Survey Of Local Area Networks For Low End Systems, Wipawadee P. Sonprasit

Retrospective Theses and Dissertations

Local area networks (LANs) that support small systems, the personal computers in particular, are surveyed. LAN environments, factors motivating interest in PC LANs, and capability requirements of LANs posed by low-end systems users, are outlined. Discussion of LAN technology includes standards, architecture, transmission media, topology, transmission techniques, access protocol, and performance factors topics. Commercial products are presented with more in-depth outline on selected products. Observation and future of PC LANs conclude the survey.

An Adaptive Multi-Scene Correlation Algorithm, Paul E. Vogt

Retrospective Theses and Dissertations

Digital scene matching algorithms have been used in both military and commercial image processing systems for years. The trend toward using multiple sensors in military imaging systems has generated anew interest in real time techniques to accomplish sensor fusion tasks such as field of view alignment. This thesis analyzes methods presently in use and introduces a novel algorithm that improves scene correlation performance. The focus of the new technique is in the segmentation area, where significant features are extracted from background and clutter. These performance improvements are especially helpful when the scene contains excessive noise and or lacks detail, a …

High Resolution Monopulse Tracking, Larry Alan Young

Retrospective Theses and Dissertations

High Resolution Radar techniques are applied to the problem of resolving a multiple target array and locating its geometric center without the usual biasing toward the brightest targets. Monopulse radar techniques are combined with high resolution stepped frequency pulse train signal processing in an amplitude tracking radar.

A single pulse monopulse system's aimpoint is biased toward the brightest point targets in an array. However, by using a stepped frequency pulse monopulse radar, the cross range distance to each individual scattered may be found.

Unlike the single pulse monopulse system, the aimpoint is independent of the reflectivity of the targets. The …

Learning Curve Model For Interrupted Production, Behzad Zarkoob

Retrospective Theses and Dissertations

Traditionally the learning curve technique has been applied to the case of continuous production. In such cases the cost par unit declines by a constant or staged percentage due to the learning phenomenon. Although this technique has been an important management tool to predict cost and productivity, there are other factors that wil~ affect the learning curves and its forecasts. One of these factors is "forgetfulness," which is caused by program interruptions for a significant period of time. It is expected that due to the interruption a relearning process may have to take place. The objective of this report is …

Comparison Of Subsurface Cavity Investigations Using Earth Resistivity, Seismograph And Ground Penetrating Radar, Dennis M. Filler

Retrospective Theses and Dissertations

Sinkhole formation in the Central Florida area has become a serious problem. The subsurface exploration method for cavity detection is indeed needed prior to sinkhole development. this research study compares the effectiveness of earth resistivity, seismograph and ground penetrating radar (GPR) methods in the detection of subsurface cavities. A resistivity instrument measures a material's resistance to electric currents. The seismograph measure the propagation velocity of a medium refracting compressional waves. The GPR transmits and receives electromagnetic pulses reflecting off subsurface interfaces.

Tests were conducted at two sites: a model test site at the University of central Florida, Orlando, and a …

Rise Time To Frequency Correlation Of Crosstalk In Coupled Microstrip Lines, Charles Michael Fletcher Jr.

Retrospective Theses and Dissertations

An examination of forward crosstalk in microstrip transmission lines is presented through a computer simulation using SPICE. A non-resistive lumped L-C transmission line model is modified to include capacitive and inductive coupling from adjacent lines. Two adjacent microstrip transmission lines are modeled, and simulation results in both the time and frequency domains are shown. The time domain or transient analysis looks at the effect of rise times on crosstalk. Rise times in the range of 100 to 1000 nanoseconds (ns) are considered. The frequency analysis shows the crosstalk frequency response over the range of 100 to 1600 kilohertz (kHz). The …

Laser Induced Darkening Semiconductor Dope Glasses, Jayant Malhotra

Retrospective Theses and Dissertations

No abstract provided.