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 …

Computer Aided Design Of Linear Phase Finite Impulse Response Digital Filters, Wentao Lyou

Retrospective Theses and Dissertations

This research report is an investigation of techniques for designing linear phase finite-duration impulse response (FIR) filters. The software package, CADFIR, developed for this project can be used to design linear phase FIR digital filters via three well-known design techniques: the window method, the frequency sampling method, and the optimal filter design method. CADFIR has options for designing such standard filters as lowpass, highpass, bandpass, and bandstop filters as well as multipassband-stopband filters. The fundamental properties of FIR filters are discussed and design algorithms associated with the three FIR filter design techniques are developed. Design examples are included and the …

Investigation Of Surface And Subsurface Deformation In Sliding Wear, Patrick J. Mohr

Retrospective Theses and Dissertations

The research presented in this paper is part of the ongoing work by Moslehy and Rice et al. at the University of Central Florida in the investigation of sliding wear using laser techniques. This research paper investigates related wear phenomena, metallographically, and presents some general trends observed in the growth of the elastic - plastic interface as a function of time. Observations were made on the surface and at near surface sections on several brass pin specimens, each being subjected to sliding wear for various periods of time. Metallographic observation of the plastic deformation that occurred on the surface of …

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 …

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 …

Numerical Solutions Of Poisson's Equation In A Superlatice Device, Norman Todd Rollins

Retrospective Theses and Dissertations

The relationship between the built-in potential and the energy bands in a heterojunction device is defined using the Anderson model. Based on this model, Poisson's equation for a nonhomogeneous semiconductor device in thermal equilibrium is derived and solved analytically for the special case of a doubly intrinsic abrupt heterojunction. Several numerical methods of solving Poisson's equation for general cases are explored to find the most efficient method. The validity of the chosen numerical method is tested against both the analytical solution for a Ge/GaAs doubly intrinsic diode and recently published results from similar numerical simulation studies. A p-i-n superlattice device …

An Ada Simulator For The Structured Functional Simulation Of A Digital Signal Processing System, Christopher Paul Roney

Retrospective Theses and Dissertations

A behavioral-level simulator designed for FIRST, a silicon compilation system for digital signal processing, is implemented in the Ada* programming language. The simulator accepts as input a digital signal processing system description written for the FIRST ([ast Implementation of aealtime ~ignal transforms) silicon compiler, and provides an interactive post-processing signal trace facility. The simulator is a time-driven simulator which contains a FIRST description language parser, a subset of the FIRST primitives, and the capacity for maintaining a full history of all signals in the system. The primitives in the FIRST description language are common to digital signal processing systems (e.g., …

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 …

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.

Utilizing Object-Oriented Design To Reduce The Effort Expended On The Maintenance Phase Of A Software Project, Susan Muriel Storma

Retrospective Theses and Dissertations

Due to poor software design, software products typically incur substantial cost overruns during the maintenance phase of the life cycle. Use of modern software engineering principles (e.g., information hiding and abstraction) can i mprove the design of a product and, hence, reduce the effort associated with the maintenance phase of a product. Object-oriented design (OOD) is a tool which embodies these software engineering principles. This paper first presents the concepts of 00D and how it is used. A design example involving a programmable temperature controller is presented utilizing 00D and is then compared to a top-down design approach. Conclusions are …

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 …

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 …

Parametric Shape Generation Of Aerodynamic And Structural Objects For Aerodynamic, Structural And Radar Cross-Section Analysis, Franklin C. Basile

Retrospective Theses and Dissertations

This thesis describes the design and development of software to parametrically build three-dimensional aerodynamic objects or shapes for various engineering design and analysis activities. The software is designed to generate and display sufficient geometric output to completely define the object. Parameters are entered through a prompting sequence which determines the type of object and the amount of geometry needed to describe the object. Geometry created by this program will act as the baseline model for aerodynamic , structural, and radar cross-section analysis. An integral part of the program is the complete 3-D viewing capability. Interactive global display capability allows for …

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 …

Development Of Techniques To Perform Simulation-Adaptation In A Simulation Training Environment Using Expert System Methods, Cheryl E. Bagshaw

Retrospective Theses and Dissertations

The use of computers for instructional purposes is steadily increasing, along with an emphasis on developing systems which create environments tailored to human beings. Artificial Intelligence techniques have been incorporated into these systems with an aim at developing better methods of modeling of simulating knowledge and intelligent behavior. One type of these systems, Intelligent Simulation Training Systems (ISTS), utilize a simulation in the training process. This is an ideal environment for the instruction of skills which focus on the ability to understand the time and space relationships of objects.

An intelligent tutor module of an ISTS must configure scenarios for …

A Student Performance Evaluation Method For An Intelligent Simulation-Based Tutoring System, Camille Marie Dixon

Retrospective Theses and Dissertations

Intelligent simulation-based tutoring systems (ISTS) present intriguing and complex environments for the training of high performance skills. These skills involve the manipulation of objects within time and space constraints.

As with any tutoring system, there must exist a performance measurement methodology. Within an ISTS there is a module which functions as a tutor and a module which functions as a student modeler. These fundamental modules are required to make effective individualized tutoring decisions. However, each of these modules rely on information from a performance measurement system or evaluation system.

The objective of this research was to establish a performance evaluation …

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 …

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 …

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 …

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 …

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 …

Computerized Data Acquisition In Experimental Applications, Jay A. Meyer

Retrospective Theses and Dissertations

This thesis project was intended to provide the University of Central Florida Mechanical Engineering and Aerospace Sciences Department with computerized data acquisition (CDA) capabilities. The data acquisition system has been designed for use in laboratory instruction and research experimentation. The development of the CDA system began in the spring of 1987. This development included the acquisition of system hardware and the design of software. The expertise required to carry out this project was obtained by many hours of laboratory experience. This experience was gained not only in university laboratories but also in international studies at the Euratom laboratory in Italy. …

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 …

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 …

Method For Sizing Mos Transistors For Vlsi, Matthew J. Amatangelo

Retrospective Theses and Dissertations

Determining the device width to length ratios has typically been an iterative process for the custom IC digital design engineer. After the logic design phase is complete for a particular circuit, the designer would make an educated guess at the device sizes. Then by trial and error, using SPICE or another circuit simulator, suitable sizes would be determined. Unfortunately, this approach is time consuming and the resulting sizes are often a good bit larger than they need to be to maintain a certain speed because of the lack of a rigorous sizing methodology. This paper describes a method for reducing …

Significant Measurements Of A Multiple Target Tracking System Utilizing Munkre's Algorithm As A Correlation Scheme, Nathalie Anna Day

Retrospective Theses and Dissertations

This thesis presents and discusses the principles of multiple target tracking. A simulation written in Turbo Pascal provides the results of using a modified version of Munkre's algorithm for correlating targets with observations. The number and types of measurements necessary to obtain acceptable results are examined. The measurements under scrutiny are range, range rate, azimuth angle and elevation angle. A track-while-scan system is assumed and the nearest neighbor correlation scheme as well as rectangular gating are used for association.

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.

Economic Design Of Lot-By-Lot Acceptance Sampling By Attributes, Michael S. Wall

Retrospective Theses and Dissertations

Risk-based sampling plans have long been the accepted standards in the practice of acceptance sampling for quality control. Usually the economic consequences of a given sampling plan are assessed by experience and intuition at best. With the availability of high speed computers and well-proven statistical methods, economically-optimal sampling pl a ns can now be developed so that much of the guesswork is removed. This study first surveys these methods for deriving economically-optimal sampling plans. Then, recognizing the reluctance in government and industry to abandoning ris k-based design of sampling plans, a method is explored which poses a compromise between the …

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 …