Engineering Commons^™

Dynamic Characterization Of Aluminum Softball Bats, Danny V. Lee

Dissertations and Theses

On January 1, 2000, the Amateur Softball Association of America (ASA) imposed maximum bat performance limitations on commercial softball bats. The ASA adopted a testing standard defined by the American Society of Testing and Materials (ASTM) to determine the bat performance factor (BPF), a normalized coefficient of restitution that must be less than 1.2 for the bat to be eligible for ASA sanctioned events.

The ASTM standard requires that the softball strike the bat, which is free to rotate in the horizontal plane, at 26.8 mfs ± 0.3 mfs (88 ftfs ± 1 ftfs) with little or no spin. The …

Decomposition Of Relations: A New Approach To Constructive Induction In Machine Learning And Data Mining -- An Overview, Marek Perkowski, Stanislaw Grygiel

Electrical and Computer Engineering Faculty Publications and Presentations

This is a review paper that presents work done at Portland State University and associated groups in years 1989 - 2001 in the area of functional decomposition of multivalued functions and relations, as well as some applications of these methods.

The Fixed Weighting Nature Of A Cross-Evaluation Model, Timothy R. Anderson, Keith Hollingsworth, Lane Inman

Engineering and Technology Management Faculty Publications and Presentations

Cross-evaluation has been touted as a powerful extension of Data Envelopment Analysis that provides, not only a unique ordering among the Decision Making Units (DMUs), but also eliminates unrealistic weighting schemes without requiring the elicitation of weight restrictions from application area experts. The goal of this paper is to prove, in the single-input, multiple-output case, cross-evaluation implicitly uses a single fixed set of weights. We demonstrate how this unseen fixed set of weights may still be unrealistic.

Modeling The Transient Rate Behavior Of Bandwidth Sharing As A Hybrid Control System, Kang Li, Molly H. Shor, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

This paper uses hybrid control to model a problem of computer network systems, the dynamic behavior of bandwidth sharing among competing TCP traffic. It has been well known in the computer network community that well-behaved (TCP-friendly) congestion control mechanisms are crucial to the robustness of the Internet. Congestion control determines the transmission rate for each flow. Right now, most TCP-friendly research focuses only on the average throughput behavior without considering how the data is sent out in the short-term (e.g. bursty or smooth). However, recent experimental results show that short-term rate adjustments can change the bandwidth sharing result. Therefore, it …

Infosphere Project: An Overview, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

We describe the Infosphere project, which is building the systems software support for information-driven applications such as digital libraries and electronic commerce. The main technical contribution is the Infopipe abstraction to support information flow with quality of service. Using building blocks such as program specialization, software feedback, domain-specific languages, and personalized information filtering, the Infopipe software generates code and manage resources to provide the specified quality of service with support for composition and restructuring.

Moving Towards Massively Scalable Video-Based Sensor Networks, Wu-Chi Feng, Jonathan Walpole, Calton Pu, Wu-Chang Feng

Computer Science Faculty Publications and Presentations

Networking and computing technologies are becoming advanced enough to enable a wealth of diverse applications that will drastically change our everyday lives. Some past examples of these developments include the World Wide Web and wireless data networking infrastructures. As is quite obvious, the World Wide Web has enabled a fundamental change in the way many people deal with day-to-day tasks. Through the web, one can now make on-line reservations for travel, pay bills through on-line banking services, and view personalized on-line newscasts. More recently, developments in wireless technologies have enabled anywhere, anytime access to information over wireless medium. As wireless …

Tidal Asymmetry In An Estuarine Pycnocline 2. Transport, David A. Jay, Cynthia N. Cudaback

Civil and Environmental Engineering Faculty Publications and Presentations

Flood currents in shallow estuaries are driven by an along-channel barotropic and baroclinic pressure gradient that increases monotonically toward the bottom, while friction retards near-bottom currents. Therefore, in many estuaries there is a middepth maximum in flood currents. We explore this phenomenon using a simple three-layer model in which each layer has vertically uniform currents and constant density. In this model the middle layer is of intermediate density and grows by shear-induced entrainment from the other two layers. This very simple model produces a middepth maximum in flood currents and simulates observed currents in the Columbia River entrance channel within …

Rate-Matching Packet Scheduler For Real-Rate Applications, Kang Li, Jonathan Walpole, Dylan Mcnamee, Calton Pu, David Steere

Computer Science Faculty Publications and Presentations

A packet scheduler is an operating system component that controls the allocation of network interface bandwidth to outgoing network flows. By deciding which packet to send next, packet schedulers not only determine how bandwidth is shared among flows, but also play a key role in determining the rate and timing behavior of individual flows. The recent explosion of rate and timing-sensitive flows, particularly in the context of multimedia applications, has focused new interest on packet schedulers. Next generation packet schedulers must not only ensure separation among flows and meet real-time performance constraints, they must also support dynamic fine-grain reallocation of …

Assessing The Rate Of Change In The Enterprise Database System Market Over Time Using Dea, Timothy R. Anderson, Keith Hollingsworth, Lane Inman

Engineering and Technology Management Faculty Publications and Presentations

This paper builds upon previous work of using Data Envelopment Analysis (DEA) to measure incremental innovation in technology by applying it to the Online Transaction Processing Market. A variable returns to scale DEA model is utilized to determine an annual rate of change in benchmarks based on data provided by the Transaction Processing Performance Council. This rate of change may then be used to forecast possible future performance trendsetters of the TPC.

Towards Comparative Profiling Of Parallel Applications With Pperfdb, Christian Leland Hansen

Dissertations and Theses

Due to the complex nature of parallel programming, it is difficult to diagnose and solve performance related problems. Knowledge of program behavior is obtained experimentally, with repeated runs of a slightly modified version of the application or the same code in different environments. In these circumstances, comparative performance analysis can provide meaningful insights into the subtle effects of system and code changes on parallel program behavior by highlighting the difference in performance results across executions.

I have designed and implemented modules which extend the PPerfDB performance tool to allow access to existing performance data generated by several commonly used tracing …

Processing Algorithms For Tracking Speckle Shifts In Optical Elastography Of Biological Tissues, Donald D. Duncan, Sean J. Kirkpatrick

Electrical and Computer Engineering Faculty Publications and Presentations

Parametric and nonparametric data processing schemes for analyzing translating laser speckle data used to investigate the mechanical behavior of biological tissues are examined. Crosscorrelation, minimum mean square estimator, maximum likelihood, and maximum entropy approaches are discussed and compared on speckle data derived from cortical bone samples undergoing dynamic loading. While it was not the purpose of this paper to demonstrate that one processing technique is superior to another, maximum likelihood and maximum entropy approaches are shown to be particularly useful when the observed speckle motion is small.

Regularity And Symmetry As A Base For Efficient Realization Of Reversible Logic Circuits, Marek Perkowski, Pawel Kerntopf, Andrzej Buller, Malgorzata Chrzanowska-Jeske, Alan Mishchenko, Xiaoyu Song, Anas Al-Rabadi, Lech Jozwiak, Alan Coppola

Electrical and Computer Engineering Faculty Publications and Presentations

We introduce a Reversible Programmable Gate Array (RPGA) based on regular structure to realize binary functions in reversible logic. This structure, called a 2 * 2 Net Structure, allows for more efficient realization of symmetric functions than the methods shown by previous authors. In addition, it realizes many non-symmetric functions even without variable repetition. Our synthesis method to RPGAs allows to realize arbitrary symmetric function in a completely regular structure of reversible gates with smaller “garbage” than the previously presented papers. Because every Boolean function is symmetrizable by repeating input variables, our method is applicable to arbitrary multi-input, multi-output Boolean …

Application Of Tree-Structured Regression For Regional Precipitation Prediction Using General Circulation Model Output, Xiangshang Li, David J. Sailor

Mechanical and Materials Engineering Faculty Publications and Presentations

This study presents a tree-structured regression (TSR) method to relate daily precipitation with a variety of free-atmosphere variables. Historical data were used to identify distinct weather patterns associated with differing types of precipitation events. Models were developed using 67% of the data for training and the remaining data for model validation. Seasonal models were built for each of 2 US sites: San Francisco, California, and San Antonio, Texas. The average correlation between observed and simulated daily precipitation data series is 0.75 for the training set and 0.68 for the validation set. Relative humidity was found to be the dominant variable …

Tidal Asymmetry In An Estuarine Pycnocline: Depth And Thickness, Cynthia N. Cudaback, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Tidal variations in estuarine stratification are revealed by the depth and thickness of the density interface. The depth of the interface may be predicted using an inviscid two-layer model that combines baroclinic estuarine circulation with barotropic tidal currents [Helfrich, 1995]. Here we present results from a two-layer model modified to include the effects of bottom friction and interfacial mixing. Modeled layer thickness and speed compare favorably with prior analytic studies [Farmer and Armi, 1986; Pratt, 1986]. We use a bulk Richardson number criterion to estimate the thickness of the pycnocline from two-layer model results; the predicted pycnocline depth and thickness …

Aspects Of Information Flow, Andrew P. Black, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Along with our colleagues at the Oregon Graduate Institute and Georgia Institute of Technology, we have recently been experimenting with real-rate systems, that is, systems that are required to move data from one place to another at defined rates, such as 30 items per second. Audio conferencing or streaming video systems are typical: they are required to deliver video or audio frames from a source (a server or file system) in one place to a sink (a display or a sound generator) in another; the frames must arrive periodically, with constrained latency and jitter. We have successfully built such systems …

Application Of Control Theory To Modeling And Analysis Of Computer Systems, Molly H. Shor, Kang Li, Jonathan Walpole, David Steere, Calton Pu

Computer Science Faculty Publications and Presentations

Experimentally, we show that Transmission Control Protocol (TCP)’s congestion control algorithm results in dynamic behavior similar to a stable limit cycle (attractor) when data from TCP flow into a fixed-size buffer and data is removed from the buffer at a fixed service rate. This setup represents how TCP buffers packets for transmission onto the network, with the network represented by a fixed-size buffer with a fixed service rate. The closed trajectory may vary slightly from period to period due to the discrete nature of computer systems. The size of the closed trajectory is a function of the network’s buffer size …

Gaussian Beams In Hollow Metal Waveguides, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Various families of Gaussian beams have been explored previously to represent the propagation of nearly plane electromagnetic waves in media having at most quadratic transverse variations of the index of refraction and the gain or loss in the vicinity of the beam. However, such beams cannot directly represent the wave solutions for propagation in planar or rectangular waveguides, and sinusoidal mode functions are more commonly used for such waveguides. On the other hand, it is also useful to consider the possibility of recurring Gaussian beams that have an approximately Gaussian transverse profile at certain distinct planes along the propagation path. …

Power Self-Regulation In Double-Pass High-Gain Laser Amplifiers, Lee W. Casperson, Janet M. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Double-pass laser amplifiers can provide automatic passive regulation of the power in an optical signal. This regulation can significantly reduce the amplitude noise on a laser beam that is intended as a continuous wave light source. Analytic expressions are derived to describe the optical-noise-reduction region of double-pass amplifier operation and the dependence of the self-regulation properties on gain, saturation, and mirror reflectivity.

Intelligent Safety And Driver Assistance Systems For Heavy Duty Trucks, Volkmar Gross, Ziad Keirouz

Engineering and Technology Management Student Projects

Preface:

The number of commercial vehicles (trucks) on the U.S. Highways will continue to growth by an average annual ra!e of approximately 10% over the next 3 to 5 years. Along with the predicted increased movement of goods due to the ecommerce revolution, accidents (and death rates) involving commercial trucks are on the rise. In the following, we will investigate the future of Intelligent Safety and Driver Assistance Systems, designed to increase the overall safety of commercial vehicles, in the wake of augmented national and government interest in these technologies. We will concentrate on vehicle-based rather than infrastructure- based technologies. …

Integrated Floorplanning And Buffer Insertion For Bus-Based Microprocessor Designs, Faran Rafiq

Dissertations and Theses

In this thesis, we propose a novel algorithm for the interconnect driven floorplanning problem that integrates bus planning with floorplanning. This integrated floorplanner is intended for bus-based designs in which the layout is considered to be a set of blocks connected through buses. Each bus consists of a large number of wires. Our floorplanner allocates the exact location and shape of the interconnect (both above and between the circuit blocks) and ensures routability as well as optimizes the timing goals. Our experiments with benchmarks clearly show the superiority of integrated floorplanning approach over the classical floorplan-analyze-and-then-refloorplan approach. Our initial results …

Improved Regression-Based Streamflow Forecasting Considering Large-Scale Climate Variability, Austin R. Fisher

Dissertations and Theses

The Natural Resources Conservation Service (NRCS) produces water supply forecasts for most of the streams in the western United States. The NRCS produces forecasts starting in January, when snow course measurements of snow water equivalent were available. Although the seasonal streamflow volume forecasts made by the NRCS are useful, many water supply managers need information at the beginning of the water year in October and would like to see forecasts in the form of a monthly hydrograph.

An investigation into the effect of decadal scale variability, as reflected by the Pacific Decadal Oscillation (PDO), show important relationships that may be …

Design And Evaluation Of A Specialized Computer Architecture For Manipulating Binary Decision Diagrams, Robert K. Hatt

Dissertations and Theses

Binary Decision Diagrams (BDDs) are an extremely important data structure used in many logic design, synthesis and verification applications. Symbolic problem representations make BDDs a feasible data structure for use on many problems that have discrete representations. Efficient implementations of BOD algorithms on general purpose computers has made manipulating large binary decision diagrams possible. Much research has gone into making BOD algorithms more efficient on general purpose computers. Despite amazing increases in performance and capacity of such computers over the last decade, they may not be the best way to solve large, specialized problems. A computer architecture designed specifically to …

Work In Progress: Automating Proportion/Period Scheduling, David Steere, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

The recent effort to define middleware capable of supporting real-time applications creates the opportunity to raise the level of abstraction presented to the programmer. We propose that proportion/period is a better abstraction for specifying resource needs and allocation than priorities. We are currently investigating techniques to address some issues that are restricting use of proportion/period scheduling to research real-time prototypes. In particular, we are investigating techniques to automate the task of selecting proportion and period, and that allow proportion/period to incorporate job importance under overload conditions.

Investigation Of Image Feature Extraction By A Genetic Algorithm, Steven P. Brumby, James P. Theiler, Simon J. Perkins, Neal R. Harvey, John J. Szymanski, Jeffrey J. Bloch, Melanie Mitchell

Computer Science Faculty Publications and Presentations

We describe the implementation and performance of a genetic algorithm which generates image feature extraction algorithms for remote sensing applications. We describe our basis set of primitive image operators and present our chromosomal representation of a complete algorithm. Our initial application has been geospatial feature extraction using publicly available multi-spectral aerial-photography data sets. We present the preliminary results of our analysis of the efficiency of the classic genetic operations of crossover and mutation for our application, and discuss our choice of evolutionary control parameters. We exhibit some of our evolved algorithms, and discuss possible avenues for future progress.

Implementation And Performance Of Error Correction Codes For High-Speed Computer Networks, Jochen Spengler

Dissertations and Theses

During the transmission of data there is always a possibility that errors occur and some pieces are modified. If the receiver detects an error it either sends a request for retransmission or, like in networks using Ethernet, it does not send an acknowledgment for the erroneous frame. In this case the sender waits a certain time and retransmits the frame. With the development of faster computer networking hardware and the need for more real-time applications, these errors have become a major concern. Long retransmission latencies and the need for large memories for buffering drive the development of more reliable network …

Qos Scalability For Streamed Media Delivery, Charles Krasic, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Applications with real-rate progress requirements, such as mediastreaming systems, are difficult to deploy in shared heterogenous environments such as the Internet. On the Internet, mediastreaming systems must be capable of trading off resource requirements against the quality of the media streams they deliver, in order to match wide-ranging dynamic variations in bandwidth between servers and clients. Since quality requirements tend to be user- and task-specific, mechanisms for capturing quality of service requirements and mapping them to appropriate resource-level adaptation policies are required. In this paper, we describe a general approach for automatically mapping user-level quality of service specifications onto resource …

Fine-Grain Period Adaptation In Soft Real-Time Environments, David Steere, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Reservation-based scheduling delivers a proportion of the CPU to jobs over a period of time. In this paper we argue that automatically determining and assigning this period is both possible and useful in general purpose soft real-time environments such as personal computers and information appliances. The goal of period adaptation is to select the period over which a job is guaranteed to receive its portion of the CPU dynamically and automatically. The choice of period represents a trade-off between the amount of jitter observed by the job and the overall efficiency of the system. Secondary effects of period include quantization …

Capillary Surfaces In An Exotic Container: Results From Space Experiments, Paul Concus, Robert Finn, Mark M. Weislogel

Mechanical and Materials Engineering Faculty Publications and Presentations

Experimental results from the Interface Configuration Experiment (ICE) performed aboard the Space Shuttle and the Mir Space Station are reported. The experiment concerns fluid interfaces in certain ‘exotic’ containers in a low-gravity environment. These containers are rotationally symmetric and have the property that for given contact angle and liquid volume, a continuum of distinct rotationally symmetric equilibrium configurations can appear, all of which have the same mechanical energy. These symmetric equilibrium configurations are unstable, in that deformations that are not rotationally symmetric can be shown mathematically to yield configurations with lower energy. It is found experimentally, in confirmation of mathematical …

Double-Pass High-Gain Laser Amplifiers, Janet M. Casperson, Frederick G. Moore, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Double-pass laser amplifiers have advantages of compactness and efficiency in the amplification of optical signals, and such amplifiers have been employed in a wide range of optical systems. Work in this area is reviewed briefly, and analytical solutions are obtained for the intensity of the electromagnetic waves in double-pass homogeneously-broadened high-gain laser amplifiers. Expressions are derived relating the output power to the input, including the effects of arbitrary mirror reflectivity and frequency detuning from line center. In the limits of weak saturation and of high reflectivity the results are consistent with earlier studies.

Anti-Blooming Nightvision: Extending Global Dynamic Range By Neural Network Image Fusion, Daniel L. Schuster

Dissertations and Theses

Sensor saturation in the presence of bright objects can create a non-restorable loss of image information as the spatial gradient tends to zero. Blooming is an attendant morphological corruption of image data that plagues quantum well sensors, and in particular, low-light Charge-Coupled Devices (CCD's) used for nightvision applications. A novel application of Radial Basis Function Neural Networks has shown promise as a means for patching gain/brightness adjusted short exposure frame detail into the bloomed regions of long exposure image frames. A computer-tethered CCD camera was used to capture robust target images, at different exposures, in a controlled light-box environment to …