Engineering Commons^™

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 …

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 …

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 …

Laser Induced Darkening Semiconductor Dope Glasses, Jayant Malhotra

Retrospective Theses and Dissertations

No abstract provided.

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 …

Optimization Of Storm Sewer Construction Costs Using A Microcomputer Program, Dawn E. Fetter

Retrospective Theses and Dissertations

When designing a storm sewer system there is a material and labor cost trade-off between changing pipe diameter for a specific flowrate while keeping physical pipe slope constant, and changing physical pipe slope for the same flowrate while keeping the pipe diameter constant.

To calculate costs associated with every possible combination of pipe diameters and excavation depth to find the optimum design for a storm sewer network without the use of a computer would be a very cumbersome task indeed. In fact, a minimum cost solution may never be found.

This paper presents a microcomputer program which assists the engineer …

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 …

Direct Digital Control Of A Liquid Level Control Unit, Barbara Viehman Lytle

Retrospective Theses and Dissertations

A system was developed to allow undergraduate engineering students the capability of simulating various types of control modes in a laboratory environment. The use of digital control and common industrail components such as transducers, recorders, and valves was implemented.

Modification to an existing bench scale process control system is outlined and demonstrated. A computer program was written which interfaces with the hardware and data acquisition software allowing the user many options to study control processes under a variety of conditions. A wide range of parameters can be selected. System parameters can be saved on disk or printed directly. Data are …

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 …

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 …

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 …

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 …

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 …

A Cellular Algorithm For Data Reduction Of Polygon Based Images, Robert James Caesar

Retrospective Theses and Dissertations

ABSTRACT The amount of information contained in an image is often much more than is necessary. Computer generated images will always be constrained by the computer's resources or the time allowed for generation. To reduce the quantity of data in a picture while preserving its apparent quality can require complex filtering of the image data. This paper presents an algorithm for reducing data in polygon based images, using different filtering techniques that take advantage of a priori knowledge as to the images' content. One technique uses a novel implementation of vertex elimination. By passing the image through a sequence of …

Mrp, Jit, And Opt: A Comparison On The Production Floor, Donna M. Denicole Christopher

Retrospective Theses and Dissertations

In order to compete in manufacturing, industry realizes it must work more efficiently with its resources. Three manufacturing techniques have been developed to assist industry in this challenge --MRP, JIT, and OPT. This paper compares these three techniques. It concentrates on the factors that affect production after vendor materials are in-house. A brief discussion of some of the implementation difficulties a company may face during the transition to a new philosophy is also addressed. Finally, a case study of a low volume, highly technical military project is evaluated and analyzed.

Management Considerations Of Productivity Issues For Local Government, Scott M. Gilbertson

Retrospective Theses and Dissertations

This report examines the issues needed to be addressed by a municipal manager and provides guidelines to follow when establishing a productivity measurement and improvement program. Examined in detail is the relationship of the municipality's quality of service delivery in relationship to productivity. The concerns of productivity in the public sector at the national and local levels are also identified.

Numerous difficulties are encountered when attempting to measure and improve productivity. Many of these difficulties are presented and several are discussed in detail. To overcome the identified difficulties, there are a number of techniques available, some of which are recently …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Heavy Metal Removal By Sedimentation Of Street Sweepings In Stormwater Runoff, Mary Elizabeth Brabham

Retrospective Theses and Dissertations

ABSTRACT Continuous flow column studies were conducted to characterize suspended sol ids and heavy metal reduct ions through sedimentation with varying overflow rates. The heavy metals tested were cadmium, zinc, copper, iron, lead, nickel and chromium. Stormwater derived samples spiked with street sweepings categorized into particle size ranges less than 500 microns in diameter were utilized in the research. Overflow rates investigated ranged from 28 to 3600 gallons per day per square foot. Theoretical predictions of suspended solids reductions with the application of Stoke's Law exceeded observed reductions for the continuous flow system. Performance curves for all reductions over the …

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 …

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, …

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 …