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Articles 71011 - 71040 of 77545

Full-Text Articles in Engineering

Applications Of Lattice Filters To Quadrature Mirror Filter Banks, Gregory R. Jaspers Jan 1988

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 …


An Ada Simulator For The Structured Functional Simulation Of A Digital Signal Processing System, Christopher Paul Roney Jan 1988

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., …


Learning Curve Model For Interrupted Production, Behzad Zarkoob Jan 1988

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 Jan 1988

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 Jan 1988

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 Jan 1988

Laser Induced Darkening Semiconductor Dope Glasses, Jayant Malhotra

Retrospective Theses and Dissertations

No abstract provided.


Packaging Engineering Education Qualitative Need Assessment, M. Douglas Sachs Jan 1988

Packaging Engineering Education Qualitative Need Assessment, M. Douglas Sachs

Masters Theses

"Packaging engineering is an interdisciplinary field which has no formal degree program to support it. While there arc packaging engineers in industry, there are no packaging engineering degrees presently being offered by our nation's colleges and universities. In order to lay a foundation upon which a degree program could be based, this thesis has investigated the needs of packaging engineering education by seeking the input of the packaging industry. This qualitative comparison has been quantified, resulting in a list of prioritized classes and topics upon which a degree program could be based"--Abstract, page ii.


Influence Of Prior Deformation On Structure And Properties Of Heat Treated Aluminum Casting Alloy, Chungwei Hsia Jan 1988

Influence Of Prior Deformation On Structure And Properties Of Heat Treated Aluminum Casting Alloy, Chungwei Hsia

Masters Theses

"A1 356 alloy is extensively used for a wide variety of casting applications. The structure is composed of primary dendrites and eutectic silicon formed during the eutectic reaction. It has long been recognized that the shape of the eutectic silicon significantly affects the ductility of the alloy. Traditionally, the morphology of the silicon is changed by certain chemical and/or thermal processes to improve the ductility. Mechanically deforming the castings to "modify" the shape of silicon has been shown by this research to be an effective alternative method to improve the spheroidization rate of eutectic silicon during heat treatment. The best …


Glass Formation And Properties In The Sm₂O₃·Al₂O₃·Sio₂ System, Erik M. Erbe Jan 1988

Glass Formation And Properties In The Sm₂O₃·Al₂O₃·Sio₂ System, Erik M. Erbe

Masters Theses

"The purpose of this investigation was to develop a samarium containing aluminosilicate glass with properties suitable for use in the treatment of rheumatoid arthritis. Microspheres made from these compositions would be neutron activated to produce radioactive Sm-153 which has beta-particle energies suitable for treating rheumatoid arthritis as well as appropriate gamma-ray emission for nuclear imaging. The properties of Sm2O3 · AI2O3 · SiO2 glasses containing 10 to 25 mole% Sm2O3 were evaluated as a function of composition. The density, refractive index, thermal expansion coefficient, and microhardness increased with increasing Sm …


Processing And Characterization Of Ceramic Fiber Reinforced Porous Matrix Composites, Wen-Chiang Tu Jan 1988

Processing And Characterization Of Ceramic Fiber Reinforced Porous Matrix Composites, Wen-Chiang Tu

Masters Theses

"The development of ceramic fiber reinforced ceramic matrix composites has been shown to be a promising approach for high toughness ceramic materials. The purpose of this work was to develop a new ceramic matrix composite(CMC) system based on a porous mullitic matrix reinforced with ceramic fibers. Unidirectional alligned fiber reinforced mullitic matrix composites were fabricated by a filament winding process. Prepregs were laminated and thermal processed in air. SEM fractographs of the composites were characterized and related to the observed load-deflection behaviors under 3-point flexure. The fracture surface expositions changed from extensive fiber tear-out to limited fiber pull-out as the …


Voltage Controlled Resistance Model For Mos Transistors, Joey Zong-Yi Jia Jan 1988

Voltage Controlled Resistance Model For Mos Transistors, Joey Zong-Yi Jia

Dissertations and Theses

The voltage controlled resistance model is developed for a reliable MOS transistor resistance mapping. The model includes both system and local parameters, and incorporates the effect of rise and fall time variations on the gate delay. MOS transistor resistance mapping is applied in logic simulation and timing verification. Also, it can be used in automatic transistor sizing and critical path analysis.


Two Dimensional And Three Dimensional Path Planning In Robotics, Hyun Suk Kim Jan 1988

Two Dimensional And Three Dimensional Path Planning In Robotics, Hyun Suk Kim

Dissertations and Theses

A methodology for 2D and 3D collision free path planning algorithm in a structured environment is presented. The isolated free convex areas are represented as a nodes in a graph, and a graph traversal strategy that dynamically allocates costs to graph path is used. Modification of the algorithm for small computational time and optimality is discussed. The 3D path planning is done in the three orthogonal two-dimensional projections of a 3D environment. Collision checking to increase the optimality for 3D paths is done in each of the three orthogonal two-dimensional subspaces.


Off-Axis Multimode Light Beam Propagation In Tapered Lenslike Media Including Those With Spatial Gain Or Loss Variation, Anthony Alan Tovar Jan 1988

Off-Axis Multimode Light Beam Propagation In Tapered Lenslike Media Including Those With Spatial Gain Or Loss Variation, Anthony Alan Tovar

Dissertations and Theses

The propagation of light beams in inhomogeneous dielectric media is considered. The derivation begins with first principles and remains general enough to include off-axis asymmetric multimode input beams in tapered lenslike media with spatial variations of gain or loss. The tapering of lenslike media leads to a number of important applications. A parabolic taper is proposed as a model for a heated axially stretched fiber taper, and beams in such media are fully characterized. Other models are proposed by the concatenation of a parabola with other taper functions.


Safety Related Model And Studies Of Trojan Nuclear Power Plant Electrical Distribution System, Hamidreza Sharifnia Jan 1988

Safety Related Model And Studies Of Trojan Nuclear Power Plant Electrical Distribution System, Hamidreza Sharifnia

Dissertations and Theses

The most important requirement for running a nuclear power plant safely is having a reliable safety system, especially during the emergency shutdown condition. For performing a scrutiny load flow and voltage drop study a detailed and comprehensive electrical model for the emergency electrical distribution system of the Trojan Nuclear Power Plant has been developed. This model includes the representation of the transformers, circuit breakers, motors, cables and load data from 4160 volts level down to the individual 480 volts loads.


Development Of Techniques To Perform Simulation-Adaptation In A Simulation Training Environment Using Expert System Methods, Cheryl E. Bagshaw Jan 1988

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 Jan 1988

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 Jan 1988

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 Jan 1988

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 Jan 1988

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 Jan 1988

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 Jan 1988

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 …


Building Knowledge Systems For The Manufacturing Support Environment: A User's Approach, Vernon Joseph Tracy Jr. Jan 1988

Building Knowledge Systems For The Manufacturing Support Environment: A User's Approach, Vernon Joseph Tracy Jr.

Theses

Knowledge systems provide a largely untapped resource for accomplishing productivity gains in the manufacturing support disciplines. Major corporations, usually under the guidance of newly formed Artificial Intelligence (A.I.) departments, are rushing to develop large knowledge systems. These large systems offer the promise of a considerable payback and therefore deserve their current attention. There also exists a wealth of smaller projects that if identified and developed, could contribute to improved corporate performance. The shortage of knowledge engineers has been the major reason why small knowledge system applications in the manufacturing support areas are not being vigorously pursued. This paper presents an …


Boundary Layer On A Continuous Flat Plate In Parallel Flow With Similar And Non-Similar Boundary Conditions, Vaughn H.M. Faber Jan 1988

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. Jan 1988

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 Jan 1988

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 Jan 1988

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 …


A New General Purpose Systolic Array For Matrix Computations, Hai Van Dinh Le Jan 1988

A New General Purpose Systolic Array For Matrix Computations, Hai Van Dinh Le

Dissertations and Theses

In this thesis, we propose a new systolic architecture which is based on the Faddeev's algorithm. Because Faddeev's algorithm is inherently general purpose, our architecture is able to perform a wide class of matrix computations. And since the architecture is systolic based, it brings massive parallelism to all of its computations. As a result, many matrix operations including addition, multiplication, inversion, LU-decomposition, transpose, and solutions to linear systems of equations can now be performed extremely fast. In addition, our design introduces several concepts which are new to systolic architectures:

- It can be re-configured during run time to perform different …


Mrp, Jit, And Opt: A Comparison On The Production Floor, Donna M. Denicole Christopher Jan 1988

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 Jan 1988

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 Jan 1988

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 …