Engineering Commons^™

Global Optimization Studies On The 1-D Phase Problem, Martin Zwick, Byrne Elliot Lovell, Jim Marsh

Complex Systems Faculty Publications and Presentations

The Genetic Algorithm (GA) and Simulated Annealing (SA), two techniques for global optimization, were applied to a reduced (simplified) form of the phase problem (RPP) in computational crystallography. Results were compared with those of "enhanced pair flipping" (EPF), a more elaborate problem-specific algorithm incorporating local and global searches. Not surprisingly, EPF did better than the GA or SA approaches, but the existence of GA and SA techniques more advanced than those used in this study suggest that these techniques still hold promise for phase problem applications. The RPP is, furthermore, an excellent test problem for such global optimization methods.

Generalized Beam Matrices. Ii. Mode Selection In Lasers And Periodic Misaligned Complex Optical Systems, Lee W. Casperson, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

A generalized beam matrix method is used to investigate the mode structure of astigmatic misaligned optical systems with loss or gain. In these optical systems the usual real-argument polynomial-Gaussian beams are not eigenfunctions, and off-axis complex-argument polynomial beams must be used. New beam transformations for these complex-argument modes are reported. Stability criteria are developed, and mode selection in laser resonators that contain tilted, displaced, or curved complex optical elements is discussed.

Jitter And Wander Reduction For A Sonet Ds3 Desynchronizer Using Predictive Fuzzy Control, Kevin Blythe Stanton

Dissertations and Theses

Excessive high-frequency jitter or low-frequency wander can create problems within synchronous transmission systems and must be kept within limits to ensure reliable network operation. The emerging Synchronous Optical NETwork (SONET) introduces additional challenges for jitter and wander attenuation equipment (called desynchronizers) when used to carry payloads from the existing Plesiochronous Digital Hierarchy (PDH), such as the DS3. The difficulty is primarily due to the large phase transients resulting from the pointer-based justification technique employed by SONET (called Pointer Justification Events or PJEs). While some previous desynchronization techniques consider the buffer level in their control actions, none has explicitly considered wander …

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

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

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

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 …

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

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.

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 …

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

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

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. …

Tbd Team Report, Jay Hah, Ziad Keirouz, Indra Surataruna, Raid Obeidi, Hun Kye

Engineering and Technology Management Student Projects

The project that team quintuple was assigned is the self-diagnosis or analysis of factors that impacted our team's performance throughout the course.

We were assigned a number of team tasks for the class that required interacting and discussing those tasks with other members, and of course performing those tasks. Those activities were the vehicles used by our team to access how well we had worked together. We noted our observations in individual journals to help us in analyzing factors at the end of the project life cycle. Several tracking tools were used in addition to journals, such as our weekly …

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

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 Si_1-x Ge_x 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 Si_1-x Ge_x channel. A high mobility p-MOSFET would improve both the circuit speed and the level of integration. …

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 …

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. …

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

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

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

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

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

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

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

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

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 …

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 …

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 …

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.