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Portland State University

1995

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Articles 1 - 30 of 33

Full-Text Articles in Engineering

Minimization Of Sum-Of-Conditional-Decoders Structures With Applications In Finite Machine Epld Design And Machine Learning, Sanof Mohamedsadakathulla Dec 1995

Minimization Of Sum-Of-Conditional-Decoders Structures With Applications In Finite Machine Epld Design And Machine Learning, Sanof Mohamedsadakathulla

Dissertations and Theses

In order to achieve superior speed in sequencer designs over competing PLD devices, Cypress brought to market an innovative architecture, CY7C361. This architecture introduced a new kind of universal logic gate, the CONDITION DECODER (CDEC). Because there are only 32 macrocells in the chip, saving only one CDEC gate can be quite important (the well-known "fit/no-fit problem"). A problem that is related to the fitting problem of the Cypress CY7C361 chip is the SOC Minimization. Due to the limited low number of macrocells in CY7C361, a high quality logic minimization to reduce the number of macrocells is very important. The …


Adaptive Methods For Distributed Video Presentation, Crispin Cowan, Shanwei Cen, Jonathan Walpole, Carlton Pu Dec 1995

Adaptive Methods For Distributed Video Presentation, Crispin Cowan, Shanwei Cen, Jonathan Walpole, Carlton Pu

Computer Science Faculty Publications and Presentations

This paper describes problems and solutions for delivering real-time, multi-media presentations across the Internet. A key characteristic of presentations of continuous media datatypes, such as digital video and audio, is their need for predictable real-time data delivery. For example, an NTSC quality video presentation requires video frames to be displayed every 1/30th of a second. Variations in this display rate can be observable as stalls or glitches in the video stream and reduce the quality of the presentation [6]. Delivering such presentations across the Internet is difficult because highly variable band- width and latency make it difficult to predict the …


Equivalent Relationship Of Function-Level Representation And Implementation Of Unified Indexing Of Fft Algorithms, Nee-Hua Cho Nov 1995

Equivalent Relationship Of Function-Level Representation And Implementation Of Unified Indexing Of Fft Algorithms, Nee-Hua Cho

Dissertations and Theses

With the advance of the VLSI technology, the FFT algorithm has been pushed further in solving the multidimensional array signal processing in real time. Many DSP chip users have tried to find ways to improve addressing huge data in multidimension systems with minimum cost and maximum performance. However, there is no efficient method to address data for 1-D to M-D FFTs.

A methodology has been defined to conquer the addressing problem of M-D FFT. It is well known that the twiddle factor matrix of Discrete Fourier Transform (DFT) can be recursively factored into basic butterfly stage matrices. The matrix can …


Malt Drying Model Verification For Efficiency Improvement, John David Kribs Nov 1995

Malt Drying Model Verification For Efficiency Improvement, John David Kribs

Dissertations and Theses

The aim of this work has been to minimize the thermal energy required to dry malt in deep beds while maintaining malt quality, and without increasing the drying time more than one hour. Malt drying usually takes place in deep bed (. 7-1 m) driers by forcing hot air through the bed. Measurements of inlet and outlet relative humidity, temperature, and airflow at a drier at Great Western Malting Company's Vancouver, Washington facility were made to find average moisture content versus time. The measurements were used to develop a wetted surface model of a malt bed. However, the model was …


Quality Of Service Specification For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier Nov 1995

Quality Of Service Specification For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

The bandwidth limitations of multimedia systems force tradeoffs between presentation data fidelity and real-time performance. For example, digital video is commonly encoded with lossy compression to reduce bandwidth and frames may be skipped during playback to maintain synchronization. These tradeoffs depend on device performance and physical data representations that are hidden by a database system. If a multimedia database is to support digital video and other continuous media data types, we argue that the database should provide a Quality of Service (QOS) interface to allow application control of presentation timing and information loss tradeoffs.

This paper proposes a data model …


Customizable Operating Systems, Jonathan Walpole, Crispin Cowan, Andrew P. Black, Jon Inouye, Calton Pu, Shanwei Cen Nov 1995

Customizable Operating Systems, Jonathan Walpole, Crispin Cowan, Andrew P. Black, Jon Inouye, Calton Pu, Shanwei Cen

Computer Science Faculty Publications and Presentations

A customizable operating system is one that can adapt to improve its functionality or performance. The need for customizable and application-specific operating systems has been recognized for many years, but they have yet to appear in the commercial market. This paper explores the notion of operating system customizability and examines the limits of existing approaches. The paper begins by surveying system structuring approaches for the safe and efficient execution of customizable operating systems. Then it discusses the burden that existing approaches impose on application software, and explores techniques for reducing this burden. Finally, support for customizability in the Synthetix project …


Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier Nov 1995

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.


Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier Nov 1995

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.


Performance Evaluation Of Specialized Hardware For Fast Global Operations On Distributed Memory Multicomputers, Rajesh Madukkarumukumana Sankaran Oct 1995

Performance Evaluation Of Specialized Hardware For Fast Global Operations On Distributed Memory Multicomputers, Rajesh Madukkarumukumana Sankaran

Dissertations and Theses

Workstation cluster multicomputers are increasingly being applied for solving scientific problems that require massive computing power. Parallel Virtual Machine (PVM) is a popular message-passing model used to program these clusters. One of the major performance limiting factors for cluster multicomputers is their inefficiency in performing parallel program operations involving collective communications. These operations include synchronization, global reduction, broadcast/multicast operations and orderly access to shared global variables. Hall has demonstrated that a .secondary network with wide tree topology and centralized coordination processors (COP) could improve the performance of global operations on a variety of distributed architectures [Hall94a]. My hypothesis was that …


Performance Analysis Of A Banyan Based Atm Switching Fabric With Packet Priority, Zhaohui Yan Oct 1995

Performance Analysis Of A Banyan Based Atm Switching Fabric With Packet Priority, Zhaohui Yan

Dissertations and Theses

Since the emergence of the Asynchronous Transfer Mode ( A TM ) concept, various switching architectures have been proposed. The multistage interconnection networks have been proposed for the switching architecture under the A TM environment. In this thesis, we propose a new model for the performance analysis of an A TM switching fabric based on single-buffered Banyan network. In this model, we use a three-state, i.e., "empty", "new" and "blocked" Markov chain model to describe the behavior of the buffer within a switching element. In addition to traditional statistical analysis including throughput and delay, we also examine the delay variation. …


Fluttering Fountains: Annular Geometry, Lee W. Casperson Sep 1995

Fluttering Fountains: Annular Geometry, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Under certain conditions of flow rate, height, and feedback, periodic or chaotic fluttering oscillations can be observed as the sheet of water from a dam or waterfall fountain descends through the air. Numerical and analytical interpretations of this phenomenon have recently been reported. The extension of these results to other fountain geometries is discussed here together with experimental observations on an annular waterfall fountain.


Mobility Modeling And Simulation Of Soi Si1-X Gex P-Mosfet, Sida Zhou Aug 1995

Mobility Modeling And Simulation Of Soi Si1-X Gex P-Mosfet, Sida Zhou

Dissertations and Theses

With increasing demand for complex and faster circuits, CMOS technologies are progressing towards the deep-submicron level. Process complexity increases dramatically, and costly techniques are to be developed to create dense field isolation and shallow junctions. Silicon-On-Insulator (SOI) may solve some of these problems. On the other hand, strained Si1-x Gex layers have been successfully grown on Si substrates and demonstrated much higher hole mobility than bulk Si. This can be used to build high-mobility p-MOSFET with a buried Si1-x Gex channel. A high mobility p-MOSFET would improve both the circuit speed and the level of integration. …


Scaling Of The Silicon-On-Insulator Si And Si1-Xgex P-Mosfets, Marijan PeršUn Aug 1995

Scaling Of The Silicon-On-Insulator Si And Si1-Xgex P-Mosfets, Marijan PeršUn

Dissertations and Theses

Two-dimensional numerical simulation was used to study the scaling properties of SOI p-MOSFETs. Based on the design criteria for the threshold voltage and DIBL, a set of design curves for different designs was developed. Data for subthreshold slope, SCE and threshold voltage sensitivity to silicon film thickness are also given. Results show that short-channel effects can be controlled by increasing the doping level or by thinning the silicon film thickness. The first approach is more effective for p+ gate design with high body doping, while the second approach is much more effective for n+ gate design with low body doping. …


Data Allocation For Distributed Programs, Liono Setiowijoso Aug 1995

Data Allocation For Distributed Programs, Liono Setiowijoso

Dissertations and Theses

This thesis shows that both data and code must be efficiently distributed to achieve good performance in a distributed system. Most previous research has either tried to distribute code structures to improve parallelism or to distribute data to reduce communication costs. Code distribution (exploiting functional parallelism) is an effort to distribute or to duplicate function codes to optimize parallel performance. On the other hand, data distribution tries to place data structures as close as possible to the function codes that use it, so that communication cost can be reduced.

In particular, dataflow researchers have primarily focused on code partitioning and …


Monte Carlo Simulations Of The Extinction Rate Of Densely Packed Spheres With Clustered And Nonclustered Geometries, Lisa M. Zurk, L. Tsang, K. H. Ding, Dale P. Winebrenner Aug 1995

Monte Carlo Simulations Of The Extinction Rate Of Densely Packed Spheres With Clustered And Nonclustered Geometries, Lisa M. Zurk, L. Tsang, K. H. Ding, Dale P. Winebrenner

Electrical and Computer Engineering Faculty Publications and Presentations

Scattering and absorption coefficients are presented from Monte Carlo simulations of electromagnetic wave propagation in a volume of densely packed, random dielectric, absorptive spheres. The particles are modeled both with and without a surface adhesion that causes them to form clustered groups. Results for scatterer densities greater than a few percent by volume differ significantly from those obtained under the independentscattering assumption. The extinction rates agree well with analytic dense-medium theory. Results also show that, on account of local fields experienced by the particles, the system absorption is different from that predicted with an assumption of independent absorption. Scattering is …


Seasonal Hidden Markov Models For Stochastic Time Series With Periodically Varying Characteristics, Arthur M. Lewis Jul 1995

Seasonal Hidden Markov Models For Stochastic Time Series With Periodically Varying Characteristics, Arthur M. Lewis

Dissertations and Theses

Novel seasonal hidden Markov models (SHMMs) for stochastic time series with periodically varying characteristics are developed. Nonlinear interactions among SHMM parameters prevent the use of the forward-backward algorithms which are usually used to fit hidden Markov models to a data sequence. Instead, Powell's direction set method for optimizing a function is repeatedly applied to adjust SHMM parameters to fit a data sequence. SHMMs are applied to a set of meteorological data consisting of 9 years of daily rain gauge readings from four sites. The fitted models capture both the annual patterns and the short term persistence of rainfall patterns across …


Generalized Beam Matrices: Gaussian Beam Propagation In Misaligned Complex Optical Systems, Anthony A. Tovar, Lee W. Casperson Jul 1995

Generalized Beam Matrices: Gaussian Beam Propagation In Misaligned Complex Optical Systems, Anthony A. Tovar, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

A novel 3 × 3 transfer-matrix method is developed to propagate off-axis Gaussian beams in astigmatic optical systems that may include tilted, displaced, or curved optical elements. Unlike in a previous generalized ray matrix formalism, optical elements that possess gain or loss such as Gaussian apertures, complex lenslike media, and amplifiers are included; and a new beam transformation is found. In addition, a novel exponential variable-reflectivity mirror, which displaces a Gaussian beam without changing its spot size, and a complex prismlike medium are introduced.


Testability Design And Testability Analysis Of A Cube Calculus Machine, Lixin Zhou May 1995

Testability Design And Testability Analysis Of A Cube Calculus Machine, Lixin Zhou

Dissertations and Theses

Cube Calculus is an algebraic model popular used to process and minimize Boolean functions. Cube Calculus operations are widely used in logic optimization, logic synthesis, computer image processing and recognition, machine learning, and other newly developing applications which require massive logic operations. Cube calculus operations can be implemented on conventional general-purpose computers by using the appropriate "model" and software which manipulates this model. The price that we pay for this software based approach is severe speed degradation which has made the implementation of several high-level formal systems impractical. A cube calculus machine which has a special data path designed to …


Water Quality Model For South Slough, Coos Bay, Oregon, Holly Kay Juza May 1995

Water Quality Model For South Slough, Coos Bay, Oregon, Holly Kay Juza

Dissertations and Theses

The South Slough Estuary is located off Coos Bay along the southern coast of Oregon. It is divided into two channels that meet and continue to Coos Bay at the Charleston Harbor. There are six major contributing streams to South Slough. After rainfall events, the level of coliform bacteria in the slough increases because of stream bacteria loading. This is due to cattle grazing in the drainage areas, failed septic systems from private homes, and sewage sludge applied to the County landfill, which drains into the slough. The Oregon Health Division has enforced a Sanitation Management Plan for Commercial Shellfish …


Improved Finite Analytic Methods For Solving Advection-Dominated Transport Equation In Highly Variable Velocity Field, Wei Cuifeng Apr 1995

Improved Finite Analytic Methods For Solving Advection-Dominated Transport Equation In Highly Variable Velocity Field, Wei Cuifeng

Dissertations and Theses

Solute transport studies frequently rely on numerical solutions of the classical advection-diffusion equation. Unfortunately, solutions obtained with traditional finite difference and finite element techniques typically exhibit excessive numerical diffusion or spurious oscillation when advection dominates, especially when velocity field is highly variable. One recently developed technique, the finite analytic method, offers an attractive alternative. Finite analytic methods utilize local analytic solutions in discrete elements to obtain the algebraic representations of the governing partial differential equations, thus eliminating the truncation error in the finite difference and the use of approximating functions in the finite element method. The finite analytic solutions have …


Mpvm: A Migration Transparent Version Of Pvm, Jeremy Casas, Dan Clark, Ravi Konuru, Steve Otto, Robert Prouty, Jonathan Walpole Apr 1995

Mpvm: A Migration Transparent Version Of Pvm, Jeremy Casas, Dan Clark, Ravi Konuru, Steve Otto, Robert Prouty, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Parallel Virtual Machine (PVM) is a widely-used software system that allows a heterogeneous set of parallel and serial UNIX-based computers to be programmed as a single message-passing parallel machine, In this paper, an extension to PVM to support dynamic process migration is presented. Support for migration is important in general-purpose workstation environments since it allows parallel computations to co-exist with other applications, using idle-cycles as they become available and off-loading from workstations when they are no longer free. A description and evaluation of the design and implementation of the prototype Migratable PVM system is presented together with some performance results.


Automatic Synthesis Of Vlsi Layout For Analog Continuous-Time Filters, David Lyle Robinson Mar 1995

Automatic Synthesis Of Vlsi Layout For Analog Continuous-Time Filters, David Lyle Robinson

Dissertations and Theses

Automatic synthesis of digital VLSI layout has been available for many years. It has become a necessary part of the design industry as the window of time from conception to production shrinks with ever increasing competition. However, automatic synthesis of analog VLSI layout remains rare.

With digital circuits, there is often room for signal drift. In a digital circuit, a signal can drift within a range before hitting the threshold which triggers a change in logic state. The effect of parasitic capacitances for the most part, hinders the timing margins of the signal, but not its functionality. The logic functionality …


Generalized Sylvester Theorems For Periodic Applications In Matrix Optics, Lee W. Casperson, Anthony A. Tovar Mar 1995

Generalized Sylvester Theorems For Periodic Applications In Matrix Optics, Lee W. Casperson, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

Sylvester's theorem is often applied to problems involving light propagation through periodic optical systems represented by unimodular 2 × 2 transfer matrices. We extend this theorem to apply to broader classes of optics-related matrices. These matrices may be 2 × 2 or take on an important augmented 3 × 3 form. The results, which are summarized in tabular form, are useful for the analysis and the synthesis of a variety of optical systems, such as those that contain periodic distributed-feedback lasers, lossy birefringent filters, periodic pulse compressors, and misaligned lenses and mirrors. The results are also applicable to other types …


Tree Restructuring Approach To Mapping Problem In Cellular Architecture Fpgas, Narahari Ramineni Feb 1995

Tree Restructuring Approach To Mapping Problem In Cellular Architecture Fpgas, Narahari Ramineni

Dissertations and Theses

This thesis presents a new technique for mapping combinational circuits to Fine-Grain Cellular-Architecture FPGAs. We represent the netlist as the binary tree with decision variables associated with each node of the tree. The functionality of the tree nodes is chosen based on the target FPGA architecture. The proposed tree restructuring algorithms preserve local connectivity and allow direct mapping of the trees to the cellular array, thus eliminating the traditional routing phase. Also, predictability of the signal delays is a very important advantage of the developed approach. The developed bus-assignment algorithm efficiently utilizes the medium distance routing resources (buses). The method …


Design Of A Digital Compensation Filter, Nader Fakhry Feb 1995

Design Of A Digital Compensation Filter, Nader Fakhry

Dissertations and Theses

The 24-bit Motorola DSP56001 processor will be used in combination with the DSP56ADC16 and the PCM-56 to design a good FIR compensation filter. Our objective is to digitize the input analog signal, and to compensate for the attenuation in the magnitude response of the digital sine wave. Two different experiments will be conducted, a hands on approach, and a simulation program. The first one will be realized directly, using the DSP system. We will determine the magnitude response of the system, and then deduce the coefficients of the FIR sin(x)/x filter. A look up table will store those values which …


Dirac's Equation In Semiclassical Physics, Lee W. Casperson Feb 1995

Dirac's Equation In Semiclassical Physics, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Dirac's equation provides the most rigorous basis known for many calculations in relativistic quantum mechanics. A set of dynamical equations having greater intuitive content can be derived from Dirac's equation without any approximations. These secondary equations govern the properties of a Dirac particle as functions of time and space and are similar to the corresponding equations governing a classical charged fluid. Several new density functions are implied by these equations and are appropriate for incorporation into the various semiclassical models of physics.


Analysis Of Intermodulation Distortion For Mesfet Small-Signal Amplifiers, Imad Saleh Ahmad Jan 1995

Analysis Of Intermodulation Distortion For Mesfet Small-Signal Amplifiers, Imad Saleh Ahmad

Dissertations and Theses

Using the nonlinear Volterra series representation, analytical expressions for the third-order intermodulation distortion power and intercept point for a MESFET small-signal amplifier are derived when its equivalent circuit is bilateral and includes the gate-to-drain capacitance (Cgd) explicitly as a nonlinear element. Previously developed analytical expressions treated Cgd as a linear element or incorporated it as part of gate-to-source and drainto- source capacitances (Cgs and Cds). These new analytical expressions are then compared with experimental data and good agreement is obtained. The analytical expressions are also used to study the variation of intermodulation distortion with …


Hardware For Fast Global Operations On Distributed Memory Multicomputers And Multiprocessors, Douglas V. Hall Jan 1995

Hardware For Fast Global Operations On Distributed Memory Multicomputers And Multiprocessors, Douglas V. Hall

Dissertations and Theses

"Grand Challenge" problems such as climate modeling to predict droughts and human genome mapping to predict and possibly cure diseases such as cancer require massive computing power. Three kinds of computer systems currently used in attempts to solve these problems are "Big Iron" multicomputers such as the Intel Paragon, workstation cluster multicomputers, and distributed shared memory multiprocessors such as the Cray T3D. Machines such as these are inefficient in executing some or all of a set of global program operations which are important in many of the "Grand Challenge" programs. These operations include synchronization, reduction, MAX, MIN, one-to-all broadcasting, all-to-all …


Variance And Uncertainty Measures Of Population Diversity Dynamics, Mark A. Bedau, Martin Zwick, Alan Bahm Jan 1995

Variance And Uncertainty Measures Of Population Diversity Dynamics, Mark A. Bedau, Martin Zwick, Alan Bahm

Systems Science Faculty Publications and Presentations

We define variance and uncertainty measures of population diversity. Both measures have precise decompositions that we can exploit in analysis of evolutionary dynamics. We discuss how these measures are related and how they can be observed in artificial and natural evolving systems.


Beam Modes Of Lasers With Misaligned Complex Optical Elements, Anthony A. Tovar Jan 1995

Beam Modes Of Lasers With Misaligned Complex Optical Elements, Anthony A. Tovar

Dissertations and Theses

A recurring theme in my research is that mathematical matrix methods may be used in a wide variety of physics and engineering applications. Transfer matrix techniques are conceptually and mathematically simple, and they encourage a systems approach. Once one is familiar with one transfer matrix method, it is straightforward to learn another, even if it is from a completely different branch of science. Thus it is useful to overview these methods, and this has been done here. Of special interest are the applications of these methods to laser optics, and matrix theorems concerning multipass optical systems and periodic optical systems …