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Full-Text Articles in Engineering

An Intelligent Database For Psubot, An Autonomous Wheelchair, Dieudonne Mayi Feb 1992

An Intelligent Database For Psubot, An Autonomous Wheelchair, Dieudonne Mayi

Dissertations and Theses

In the design of autonomous mobile robots, databases have been used mainly to store information on the environment in which the device is to operate. For most of the models and ready systems, the database when used, is not a stand alone component in the system, rather it is only intended to keep static information on the disposition and properties of objects on the map.

In this thesis is implemented an intelligent database. It combines static facts to build more information. An intelligent database such as this one will be a plus for an intended autonomous machine such as the …


Developing Image Processing Tools In X Window System, Xin Zhang Jan 1992

Developing Image Processing Tools In X Window System, Xin Zhang

Dissertations and Theses

The X Window System is an industry-standard software system which facilitates programmers to develop portable graphical user interfaces. This thesis describes an image processing tool developed under the X Window System. A multiwindow image display software with image editing and improvement functions is developed. The software has four modules: environment generation, image creation, image editing and image improvement.

The environment generation module creates working windows, scrollbars, dialogbox and pulldown menu buttons, and tracks mouse cursor positions. The working windows are three adjacent windows allowing display of three different images simultaneously. The dialogbox provides an interface between the user and the …


Porting Chorus To The Pa-Risc: Overall Evaluation, Jonathan Walpole, Marion Hakanson, Jon Inouye, Ravi Konuru Jan 1992

Porting Chorus To The Pa-Risc: Overall Evaluation, Jonathan Walpole, Marion Hakanson, Jon Inouye, Ravi Konuru

Computer Science Faculty Publications and Presentations

This document is part of a series of reports describing the design decisions made in porting the Chorus Operating System kernel to the Hewlett-Packard 9000 Series 800 workstation. This document summarizes the matches and mis-matches between Chorus and the PA-RISC and outlines the general lessons learned during the project.

This document is intended for people who are interested in (a) the separation of machinedependent micro-kernel code from machine-independent micro-kernel code, (b) the interaction between operating system design and the PA-RISC architecture, and (c) the portability ofthe Chorus operating system.

The first report in the series, Porting Chorus to the PA-RISe: …


Porting Chorus To The Pa-Risc: Booting, Jon Inouye, Ravi Konuru, Jonathan Walpole, Marion Hakanson Jan 1992

Porting Chorus To The Pa-Risc: Booting, Jon Inouye, Ravi Konuru, Jonathan Walpole, Marion Hakanson

Computer Science Faculty Publications and Presentations

We started out with the low level Tut (HP-CX 2.0) boot code. One of our goals was to reuse as much of this code as possible, which would reduce the amount of low level code we would have to debug. This was very important, especially fiince the RP 9000/834 has a very complex I/O architecture and we lacked any sophisticated debugging tools. Writing the PA-Chorus boot code involved modifying the Tut code to match the Chorus startup sequence. In the remainder of this section, we present an overview of the PA-RISC boot mechanisms and the Chorus startup sequence. Sectlon 2 …


Porting Chorus To The Pa-Risc: Virtual Memory Manager, Jon Inouye, Marion Hakanson, Ravi Konuru, Jonathan Walpole Jan 1992

Porting Chorus To The Pa-Risc: Virtual Memory Manager, Jon Inouye, Marion Hakanson, Ravi Konuru, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This document describes the port ofthe Chorus virtual memory manager to the Hewlett-Packard Precision Architecture rusc (PA-RISC) workstation. The information contained in this paper will be of interest to people who:

• intend to port the Chorus virtual memory section. • intend to port a virtual memory design to the Hewlett-Packard PA-RISC.

The reader is strongly encouraged to read the following PA-Chorus documents before reading this document:

• Technical Report CSE-92-3, Porting Chorus to the PA-RISC: Project Overview


Porting Chorus To The Pa-Risc: Project Overview, Jonathan Walpole, Marion Hakanson, Jon Inouye, Ravi Konuru Jan 1992

Porting Chorus To The Pa-Risc: Project Overview, Jonathan Walpole, Marion Hakanson, Jon Inouye, Ravi Konuru

Computer Science Faculty Publications and Presentations

This document is part of a series of reports describing the design decisions made in porting the Chorus Operating System to the Hewlett-Packard 9000 Series 800 workstation. This document presents an overview of the project, and outlines the other reports in the series and the relationships between them.


Porting Chorus To The Pa-Risc: Building, Debugging, Testing And Validation, Ravi Konuru, Marion Hakanson, Jon Inouye, Jonathan Walpole Jan 1992

Porting Chorus To The Pa-Risc: Building, Debugging, Testing And Validation, Ravi Konuru, Marion Hakanson, Jon Inouye, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This document is part of a series of reports describing the design decisions made in porting the Chorus Operating System to the Hewlett-Packard 9000 Series 800 workstation. This document describes the environment for building the Chorus kernel, the various kernel tests, and the debugging environment used for porting the Chorus operating system to the HP PA-RISC.

The information contained in this paper will be of interest to people who wish to:

• Use the PA-Chorus kernel for development and/or modification, • Know about the build environment for Chorus kernel on PA-RISC, • Know about the PA-Chorus approach to debugging, • …


Porting The Chorus Supervisor And Related Low-Level Functions To The Pa-Risc, Ravi Konuru, Marion Hakanson, Jon Inouye, Jonathan Walpole Jan 1992

Porting The Chorus Supervisor And Related Low-Level Functions To The Pa-Risc, Ravi Konuru, Marion Hakanson, Jon Inouye, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This document is part of a series of reports describing the design decisions made in porting the Chorus Operating System to the Hewlett-Packard 9000 Series 800 workstation.

The Supervisor is the name given by Chorus to a collection of low-level functions that are machine dependent and have to be implemented when Chorus is ported from one machine to another. The Supervisor is responsible for interrupt, trap and exception handling, managing low-level thread initialization, context switch, kernel initialization, managing simple devices (timer and console) and offering a low-level debugger. This document describes the port of the Supervisor and related low-level functions. …


Performance Analysis Of Doa Estimation Algorithms Using Physical Parameters, Hui Liu Jan 1992

Performance Analysis Of Doa Estimation Algorithms Using Physical Parameters, Hui Liu

Dissertations and Theses

Analytical performance analysis on Direction-Of-Arrival (DOA) estimation algorithms has attracted much excellent research in recent years, various statistical properties have been revealed. However, in most of these analyses, insights of the performance were masked because of the involvement of singular values and singular vectors which depend on the character of the algorithms and data structures in a complex and nonlinear manner.


Multiplexed Pipelining : A Cost Effective Loop Transformation Technique, Satish Pai Jan 1992

Multiplexed Pipelining : A Cost Effective Loop Transformation Technique, Satish Pai

Dissertations and Theses

Parallel processing has gained increasing importance over the last few years. A key aim of parallel processing is to improve the execution times of scientific programs by mapping them to many processors. Loops form an important part of most computational programs and must be processed efficiently to get superior performance in terms of execution times. Important examples of such programs include graphics algorithms, matrix operations (which are used in signal processing and image processing applications), particle simulation, and other scientific applications. Pipelining uses overlapped parallelism to efficiently reduce execution time.


A New Method For Calculating The Economic Benefits Of Varying Degrees Of Power Factor Correction For Industrial Plant Loads, Mohammed Ishaque Jan 1992

A New Method For Calculating The Economic Benefits Of Varying Degrees Of Power Factor Correction For Industrial Plant Loads, Mohammed Ishaque

Dissertations and Theses

A comparative study of the economic benefits that can be obtained from different degrees of power factor correction for medium and small scale industrial installations is shown. A new approach for precise calculation of kws and kvars required at different power factors is presented. These calculated values are used to find the return on investments for the capacitors needed for power factor correction. The developed method is easy to use, cost effective, accurate and will help electrical engineers with minimum knowledge of power systems to precisely determine the savings available by improving the power factor of an industrial load.


Tapered Radio Frequency Transmission Lines, Vincent D. Matarrese Jan 1992

Tapered Radio Frequency Transmission Lines, Vincent D. Matarrese

Dissertations and Theses

A transformation used to obtain solutions for the beam parameter equation of fiber optics is applied to the second order differential equation for nonuniform transmission lines. Methods are developed for deriving possible transmission line tapers from known solutions of the transformed equation. This study begins with a comprehensive overview of previous work done to obtain closed-form solutions for the transmission line equations. Limitations of the lumped parameter model are also discussed. As part of this thesis, a tapered transmission line is constructed, based on one of the solutions obtained from the fiber optics studies. A discussion of the design and …


Characterization Of Quantization Noise In Oversampled Analog To Digital Converters, Eric W. Multanen Jan 1992

Characterization Of Quantization Noise In Oversampled Analog To Digital Converters, Eric W. Multanen

Dissertations and Theses

The analog to digital converter (ADC) samples a continuous analog signal and produces a stream of digital words which approximate the analog signal. The conversion process introduces noise into the digital signal. In the case of an ideal ADC, where all noise sources are ignored, the noise due to the quantization process remains. The resolution of the ADC is defined by how many bits are in the digital output word. The amount of quantization noise is clearly related to the resolution of the ADC. Reducing the quantization noise results in higher effective resolution.


Parameter Uncertainty And Modeling Of Sludge Dewatering In One Dimension, Joseph H. Plaskett Jan 1992

Parameter Uncertainty And Modeling Of Sludge Dewatering In One Dimension, Joseph H. Plaskett

Dissertations and Theses

Separation of liquid from solids is a necessary step in the ultimate disposal of wastewater sludges. Most commonly, sludges are dewatered by pressure-filtration methods. Mathematical models of the physics of the sludge dewatering process would provide the ability to predict dewatering performance and optimize the design and operation of dewatering facilities.


Spontaneous Coherent Pulsations In Standing-Wave Laser Oscillators : Stability Criteria, Pitak Chenkosol Jan 1992

Spontaneous Coherent Pulsations In Standing-Wave Laser Oscillators : Stability Criteria, Pitak Chenkosol

Dissertations and Theses

The stability criteria for single-mode standing-wave laser oscillators in the strongly homogeneously broadened limit are reported for the first time. Two types of stability criteria are presented. The first type, called type 1, corresponds to the minimum value of threshold parameter for which an infinitesimal perturbation away from steady state grows into an oscillatory solution. Another type of stability criteria, called type 2, corresponds to the minimum value of threshold parameter for which large amplitude oscillatory solutions do not decay to the steady state solution. Undamped pulsations in single mode strongly homogeneously broadened standing-wave laser oscillators are found to occur …


A Partitioning-Based Approach To The Fitting Problem In Special Architecture Eplds, Steffan Goller Jan 1992

A Partitioning-Based Approach To The Fitting Problem In Special Architecture Eplds, Steffan Goller

Dissertations and Theses

In this thesis, we describe an architecture-driven fitting algorithm for an Application-Specific EPLD, the CY7C361, from Cypress Semiconductor. Traditional placement and routing tools for PLDs perform placement and routing separately. Several placement possibilities are created and the router tries to realize the connections between the physical locations of the cells on the chip. The Cypress CY7C361 has a very unique chip architecture with a highly limited connectivity between the physical cells. Therefore, it is necessary to consider the mutability when the placement of cells is performed. The combination of the two stages is called fitting. The specific architecture-dependent constraints, imposed …


Limits Of Limit Equilibrium And Finite Element Techniques Applied To Cracked Debris Dams On Collapsing Foundations, Stanley Soliday Jr. Dec 1991

Limits Of Limit Equilibrium And Finite Element Techniques Applied To Cracked Debris Dams On Collapsing Foundations, Stanley Soliday Jr.

Dissertations and Theses

Limits of slope stability, limit equilibrium methods, and of the finite element code FEADAM are reached in the application of these methods to the problem of cracked dams constructed on collapsing soils.

Utilizing a generic dam, various classic slope stability approaches are tested as possible dam slope failure mechanisms. Slope stability methods are rejected as a way to accurately define and quantify the collapse problem. As a result of this work a block rotation mode of collapse is postulated. Then the finite element method (FEM) is used to try to define and quantify the collapse problem. The FEM is applied …


Ignoring Interprocessor Communication During Scheduling, Chintamani M. Patwardhan Dec 1991

Ignoring Interprocessor Communication During Scheduling, Chintamani M. Patwardhan

Dissertations and Theses

The goal of parallel processing is to achieve high speed computing by partitioning a program into concurrent parts, assigning them in an efficient way to the available processors, scheduling the program and then executing the concurrent parts simultaneously. In the past researchers have combined the allocation of tasks in a program and scheduling of those tasks into one operation. We define scheduling as a process of efficiently assigning priorities to the already allocated tasks in a program. Assignment of priorities is important in cases when more than one task at a processor is ready for execution. Most heuristics for scheduling …


A Multiple Coupled Microstrip Transmission Line Model For High-Speed Vlsi Interconnect Simulation, Lawrence Stevan Uzelac Dec 1991

A Multiple Coupled Microstrip Transmission Line Model For High-Speed Vlsi Interconnect Simulation, Lawrence Stevan Uzelac

Dissertations and Theses

A model is presented which incorporates the advantages of a mixed mode simulation to characterize transmission line behavior in multiple coupled Transmission line systems. The model is intended for use by digital circuit designers who wish to be able to obtain accurate transmission line behavior for complex digital systems for which continuous time simulation tools such as SPICE would be time prohibitive.

The model uses a transverse electromagnetic wave approximation to obtain solutions to the basic transmission line equations. A modal analysis technique is used to solve for the attenuation and propagation constants for the transmission lines. Modal analysis done …


Spectral And Spatial Quantum Efficiency Of Algaas/Gaas And Ingaas/Inp Pin Photodiodes, Steven Alan Tabor Dec 1991

Spectral And Spatial Quantum Efficiency Of Algaas/Gaas And Ingaas/Inp Pin Photodiodes, Steven Alan Tabor

Dissertations and Theses

This thesis reports a novel system capable of testing both the spectral responsivity and the spatial quantum efficiency uniformity of heterostructure photodiodes using optical fiber coupled radiation. Testing was performed to confirm device specifications. This study undertakes to quantify the spectral bandwidth of an AlGaAs I GaAs double heterostructure photodiode and two InGaAs I InP double heterostructure PIN photodiodes at D.C., through the use of spatial scanning. The spatial scanning was done using lasers at 670 nm, 780 nm, 848 nm, 1300 nm, and 1550 nm, coupled through singlemode optical fiber. The AlGaAs I GaAs material system covers the 600 …


Development Of An Advisory System For Indoor Radon Mitigation, Patricia Hiromi Byrne Nov 1991

Development Of An Advisory System For Indoor Radon Mitigation, Patricia Hiromi Byrne

Dissertations and Theses

A prototype hybrid knowledge-based advisory system for indoor radon mitigation has been developed to assist Pacific Northwest mitigators in the selection and design of mitigation systems for existing homes. The advisory system employs a heuristic inferencing strategy to determine which mitigation techniques are applicable, and applies procedural methods to perform the fan selection and cost estimation for particular techniques. The rule base has been developed employing knowledge in existing publications on radon mitigation. Additional knowledge has been provided by field experts. The benefits of such an advisory system include uniform record-keeping and consistent computations for the user, and verification of …


Comparison Of Spice And Network C Simulation Models Using The Cam System, Wen-Tsung Yen Nov 1991

Comparison Of Spice And Network C Simulation Models Using The Cam System, Wen-Tsung Yen

Dissertations and Theses

The performance of SPICE and Network C (NC) circuit simulator when simulating MOS transistor circuits has been investigated and compared. SPICE analog model, NC analog model and NC MOS_PWL model are the three MOS transistor models being used. The comparison between SPICE and NC includes five areas. They are MOS transistor model, circuit analysis and computational methods, limitation on the ability to simulate circuits containing the MOS transistor diode configuration, run time and the ability to build new circuit component models using derived equations.

The prototype circuit being used is the Content-Addressable Memory (CAM) circuit. The CAM circuit is a …


Stochastic Hydrologic Modeling In Real Time Using A Deterministic Model (Streamflow Synthesis And Reservoir Regulation Model), Time Series Model, And Kalman Filter, Philip Kwok Fan Tang Nov 1991

Stochastic Hydrologic Modeling In Real Time Using A Deterministic Model (Streamflow Synthesis And Reservoir Regulation Model), Time Series Model, And Kalman Filter, Philip Kwok Fan Tang

Dissertations and Theses

The basic concepts of hydrologic forecasting using the Streamflow Synthesis And Reservoir Regulation Model of the U.S. Army Corps of Engineers, auto-regressive-moving-average time series models (including Greens' functions, inverse functions, auto covariance Functions, and model estimation algorithm), and the Kalman filter (including state space modeling, system uncertainty, and filter algorithm), were explored. A computational experiment was conducted in which the Kalman filter was applied to update Mehama local basin model (Mehama is a 227 sq. miles watershed located on the North Santiam River near Salem, Oregon.), a typical SSARR basin model, to streamflow measurements as they became available in simulated …


Green's Law Revisited: Tidal Long-Wave Propagation In Channels With Strong Topography, David A. Jay Nov 1991

Green's Law Revisited: Tidal Long-Wave Propagation In Channels With Strong Topography, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Green's Law states that tidal long-wave elevation ζ and tidal transport Q vary with width b and depth h according to ζ ≌ b−1/2h−1/4 and Qb+1/2h+/4. This solution is of limited utility because it is restricted to inviscid, infinitesimal waves in channels with no mean flow and weak topography (those with topographic scale L ≫ wavelength λ). An analytical perturbation model including finite-amplitude effects, river flow, and tidal flats has been used to show that (1) wave behavior to lowest order is a function of only two nondimensional parameters representing, respectively, …


Field-Equation Approximations And Amplification In High-Gain Lasers: Numerical Results, Lee W. Casperson Sep 1991

Field-Equation Approximations And Amplification In High-Gain Lasers: Numerical Results, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

It has recently been shown that a field-equation time-derivative approximation that is commonly used in studies of laser-oscillator dynamics is not necessary and can lead to significant errors for some lasers. A related space-derivative approximation is widely used in studies of steady-state laser amplifiers. A more rigorous amplifier formalism is developed here, and the results are exact solutions of Maxwell’s equations. The improved model predicts a spatial instability, single mirror oscillation, and other interesting field behavior.


Field-Equation Approximations And Amplification In High-Gain Lasers: Analytical Results, Lee W. Casperson Sep 1991

Field-Equation Approximations And Amplification In High-Gain Lasers: Analytical Results, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

In a related study the equations governing a high-gain laser amplifier have been solved numerically without making the usual slowly-varying-amplitude derivative approximation in Maxwell’s equations, and thus the field amplitudes are not restricted to vary negligibly in a distance of one wavelength. The results reveal an instability that involves reflections and oscillatory growth of perturbations away from steady state. In the present study steady-state solutions of the field equations are obtained analytically, and transformations are described for converting the equations to alternative intensity-equation sets. These intensity equations are linearized and solved for the growth rate and oscillation period of the …


An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider Aug 1991

An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider

Dissertations and Theses

Since the need of energy conservation has become more and more urgent in the past decades, there has been an increased interest in the study and development of more efficient energy conversion systems. One of the fields that have arisen from that endeavor is a branch of physics called Finite Time Thermodynamics (FIT). It may be said that FIT was initiated through the famous paper by Curzon and Ahlborn (1975) that established new bounds on the efficiency of a finite time Carnot heat engine. Before, the traditional treatments gave a fundamental upper limit on the efficiency of any heat engine. …


Associative Processing Implemented With Content-Addressable Memories, Luis Sergio Kida Jul 1991

Associative Processing Implemented With Content-Addressable Memories, Luis Sergio Kida

Dissertations and Theses

The associative processing model provides an alternative solution to the von Neumann bottleneck. The memory of an associative computer takes some of the responsibility for processing. Only intermediate results are exchanged between memory and processor. This greatly reduces the amount of communication between them. Content-addressable memories are one implementation of memory for this computational model. Associative computers implemented with CAMs have reported performance improvements of three orders of magnitude, which is equivalent to the performance of the same application running in a conventional computer with clock frequencies of the order of GHz. Among the benefits of content-addressable memories to the …


Computer-Based Parameter Visualization And Decision Making For The Detection And Prediction Of Ovulation: The Ovulo-Computer, Omar Rodolfo Bermudez Jul 1991

Computer-Based Parameter Visualization And Decision Making For The Detection And Prediction Of Ovulation: The Ovulo-Computer, Omar Rodolfo Bermudez

Dissertations and Theses

It is now well accepted by gynecologists that a woman can conceive from an act of intercourse for a maximum of seven days of her menstrual cycle [1]. The reliability of natural family planning methods depends on identifying this window of fertility without ambiguity. Several natural family planning (NFP) methods have been used extensively and with some success. For decades, cycle length and BBT history have been used to forecast the most likely days of ovulation. When greater precision is needed, serum LH assays or ultrasound techniques are used. With the recent development of enzyme-linked immunosorbent assay, various kits have …


Pump Polarization Effects In Cw Dye Lasers, Lee W. Casperson, W. J. Sandle, A. C. Wilson, D. M. Warrington, R. J. Ballagh Jun 1991

Pump Polarization Effects In Cw Dye Lasers, Lee W. Casperson, W. J. Sandle, A. C. Wilson, D. M. Warrington, R. J. Ballagh

Electrical and Computer Engineering Faculty Publications and Presentations

The effects of pump polarization on the performance of cw dye lasers have been investigated. A recently developed semiclassical model for synchronously pumped mode‐locked dye lasers is adapted to the problem of cw dye‐laser oscillation, and analytic expressions are obtained for the relationship between the pump power, pump polarization, and dye‐laser output power. The theoretical results are compared with experimental data obtained using an argon‐laser‐pumped rhodamine 6G dye laser.