Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Portland State University

Series

2001

Discipline
Keyword
Publication

Articles 1 - 23 of 23

Full-Text Articles in Engineering

Lower Willamette River Model: Model Calibration, Chris Berger, Robert Leslie Annear, Scott A. Wells Dec 2001

Lower Willamette River Model: Model Calibration, Chris Berger, Robert Leslie Annear, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Water Environment Services of Clackamas County is in the process of planning upgrades on several of its wastewater treatment plants (WWTPs) which discharge into the Lower Willamette River. The goals of the modeling effort were to:

• Gather data to construct a computer simulation model of the Lower Willamette River system in order to evaluate the impact of the WWTP discharges on water quality

• Ensure that the model accurately represents the system physics and chemistry (flow, temperature, dissolved oxygen and nutrient dynamics) by model calibration

• Use the model to evaluate how to meet various future discharge scenarios for …


Capillary Flow In Interior Corners: The Infinite Column, Mark M. Weislogel Nov 2001

Capillary Flow In Interior Corners: The Infinite Column, Mark M. Weislogel

Mechanical and Materials Engineering Faculty Publications and Presentations

Capillary flow of a sinusoidally perturbed liquid column in an interior corner of infinite extent is solved using lubrication theory. Due primarily to the length scales selected to nondimensionalize the momentum equation, an analytic time scale governing the settling of the perturbation is determined. The time scale, which is shown to be independent of a steady base state flow, proves useful in rapidly predicting transients for surface settling in certain liquid-bearing tanks of spacecraft employing interior corners for fluids management purposes. The asymptotic analysis is extended to address flows along interior corners whose faces are slightly nonplanar. The generalized formulation …


Lower Willamette River Model: Boundary Conditions And Model Setup, Herman G. Rodriguez, Robert Leslie Annear, Scott A. Wells, Chris Berger Nov 2001

Lower Willamette River Model: Boundary Conditions And Model Setup, Herman G. Rodriguez, Robert Leslie Annear, Scott A. Wells, Chris Berger

Civil and Environmental Engineering Faculty Publications and Presentations

Water Environment Services of Clackamas County is in the process of planning upgrades on several of its sewage treatment plants which discharge into the Lower Willamette River. The goals of the modeling effort are to:

• Gather data to construct a computer simulation model of the Lower Willamette River system including part of the Lower Columbia River and the Willamette River above the Oregon City Falls; Because of the tidal influence in the Lower Willamette River, portions of the Columbia River that might affect the Lower Willamette River water quality were also modeled. Also, a section of the Willamette River …


Upper Spokane River Model: Boundary Conditions And Model Setup, 1991 And 2000, Robert Leslie Annear, Chris Berger, Scott A. Wells Nov 2001

Upper Spokane River Model: Boundary Conditions And Model Setup, 1991 And 2000, Robert Leslie Annear, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to:

• Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam

• Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics)

A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), is being applied …


Freightliner Llc Manufacturing Optimization, Jerry Compton, Ryan Jefferis, Hasnah Mat-Amin, Felix Ngoussou Oct 2001

Freightliner Llc Manufacturing Optimization, Jerry Compton, Ryan Jefferis, Hasnah Mat-Amin, Felix Ngoussou

Engineering and Technology Management Student Projects

Freightliner LLC has been producing innovative products since 1942 for the trucking industry. Following a 1981 acquisition by Daimler-Benz AG, Freightliner has steadily gained market share through acquisition and fleet sales. Following record production in 1999 at maximum yield levels, year 2000 hit the heavy truck market especially hard. High diesel fuel prices, low used truck values, and a slowing economy were just a few reasons for reduced truck sales.

Through Ql of 2001, heavy vehicle production was down 54% compared to 2000 in attempts of lowering inventory amounts. In this new market, capacity is no longer the overall manufacturing …


Gaussian Beams In Hollow Metal Waveguides: Experiment, Marius Ghita, Lee W. Casperson Oct 2001

Gaussian Beams In Hollow Metal Waveguides: Experiment, Marius Ghita, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Gaussian beams have been widely used for propagating electromagnetic waves in free space and in certain other optical systems. It has been suggested that recurring forms of such beams might also be useful for propagation in planar or rectangular metal waveguides. Experimental verification of the recurrence of the Gaussian field distribution in metal waveguides is reported here.


Reifying Communication At The Application Level, Andrew P. Black, Jie Huang, Jonathan Walpole Oct 2001

Reifying Communication At The Application Level, Andrew P. Black, Jie Huang, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Middleware, from the earliest RPC systems to recent Object-Oriented Remote Message Sending (RMS) systems such as Java RMI and CORBA, claims transparency as one of its main attributes. Coulouris et al. define transparency as “the concealment from the … application programmer of the separation of components in a distributed system.” They go on to identify eight different kinds of transparency.

We considered titling this paper “Transparency Considered Harmful”, but that title is misleading because it implies that all kinds of transparency are bad. This is not our view. Rather, we believe that the choice of which transparencies should be offered …


Implicit Algorithms For Multi-Valued Input Support Manipulation, Alan Mishchenko, Craig Files, Marek Perkowski, Bernd Steinbach, Christina Dorotska Sep 2001

Implicit Algorithms For Multi-Valued Input Support Manipulation, Alan Mishchenko, Craig Files, Marek Perkowski, Bernd Steinbach, Christina Dorotska

Electrical and Computer Engineering Faculty Publications and Presentations

We present an implicit approach to solve problems arising in decomposition of incompletely specified multi-valued functions and relations. We introduce a new representation based on binaryencoded multi-valued decision diagrams (BEMDDs). This representation shares desirable properties of MDDs, in particular, compactness, and is applicable to weakly-specified relations with a large number of output values. This makes our decomposition approach particularly useful for data mining and machine learning. Using BEMDDs to represent multi-valued relations we have developed two complementary input support minimization algorithms. The first algorithm is efficient when the resulting support contains almost all initial variables; the second is efficient when …


Fast Heuristic Minimization Of Exclusive-Sums-Of-Products, Alan Mishchenko, Marek Perkowski Aug 2001

Fast Heuristic Minimization Of Exclusive-Sums-Of-Products, Alan Mishchenko, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Exclusive-Sums-Of-Products (ESOPs) play an important role in logic synthesis and design-for-test. This paper presents an improved version of the heuristic ESOP minimization procedure proposed in [1,2]. The improvements concern three aspects of the procedure: (1) computation of the starting ESOP cover; (2) increase of the search space for solutions by applying a larger set of cube transformations; (3) development of specialized datastructures for robust manipulation of ESOP covers. Comparison of the new heuristic ESOP minimizer EXORCISM-4 with other minimizers (EXMIN2 [3], MINT [4], EXORCISM-2 [1] and EXORCISM3 [2]) show that, in most cases, EXORCISM-4 produces results of comparable or better …


A General Decomposition For Reversible Logic, Marek Perkowski, Lech Jozwiak, Pawel Kerntopf, Alan Mishchenko, Anas Al-Rabadi, Alan Coppola, Andrzej Buller, Xiaoyu Song, Svetlana Yanushkevich, Vlad P. Shmerko, Malgorzata Chrzanowska-Jeske, Mozammel Huq Azad Khan Aug 2001

A General Decomposition For Reversible Logic, Marek Perkowski, Lech Jozwiak, Pawel Kerntopf, Alan Mishchenko, Anas Al-Rabadi, Alan Coppola, Andrzej Buller, Xiaoyu Song, Svetlana Yanushkevich, Vlad P. Shmerko, Malgorzata Chrzanowska-Jeske, Mozammel Huq Azad Khan

Electrical and Computer Engineering Faculty Publications and Presentations

Logic synthesis for reversible logic differs considerably from standard logic synthesis. The gates are multi-output and the unutilized outputs from these gates are called “garbage”. One of the synthesis tasks is to reduce the number of garbage signals. Previous approaches to reversible logic synthesis minimized either only the garbage or (predominantly) the number of gates. Here we present for the first time a method that minimizes concurrently the number of gates, their total delay and the total garbage. Our method adopts for reversible logic many ideas developed previously for standard logic synthesis (such as Ashenhurst/Curtis Decomposition, Dietmeyer’s Composition, non-linear preprocessing …


Globally Convergent Approximate Dynamic Programming Applied To An Autolander, J.J. Murray, Richard Saeks, C.J. Cox, George G. Lendaris Jun 2001

Globally Convergent Approximate Dynamic Programming Applied To An Autolander, J.J. Murray, Richard Saeks, C.J. Cox, George G. Lendaris

Systems Science Faculty Publications and Presentations

A globally convergent nonlinear Approximate Dynamic Programming algorithm is described, and an implementation of the algorithm in the linear case is developed. The resultant linear Approximate Dynamic Programming algorithm is illustrated via the design of an autolander for the NASA X-43 research aircraft, without a priori knowledge of the X-43's flight dynamics.


Bi-Decomposition Of Multi-Valued Relations, Alan Mishchenko, Marek Perkowski, Bernd Steinbach Jun 2001

Bi-Decomposition Of Multi-Valued Relations, Alan Mishchenko, Marek Perkowski, Bernd Steinbach

Electrical and Computer Engineering Faculty Publications and Presentations

This presentation discusses an approach to decomposition of multivalued functions and relations into networks of two-input gates implementing multi-valued MIN and MAX operations. The algorithm exploits both the incompleteness of the initial specification and the flexibilities generated in the process of decomposition. Experimental results over a set of multi-valued benchmarks show that this approach outperforms other approaches in the quality of final results and CPU time.


Infopipes—An Abstraction For Information Flow, Jie Huang, Andrew P. Black, Jonathan Walpole, Calton Pu Jun 2001

Infopipes—An Abstraction For Information Flow, Jie Huang, Andrew P. Black, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

Building Object-Oriented Distributed Systems has been facilitated by Remote Message Sending (RMS) systems like Java RMI and implementations of CORBA. However, RMS systems are designed to support request/response interactions. Streaming applications, in contrast, are characterized by high-bandwidth, long-duration communication with stringent performance requirements. Examples of streaming applications include video-on-demand, teleconferencing, on-line education, and environmental observation. These applications transfer huge amounts of data and focus on distributed information flow rather than request/response.

To simplify the task of building distributed streaming applications, we propose a new abstraction for information flow—Infopipes. Using Infopipes, information flow becomes the heart of the system, not an …


Decomposition Of Relations: A New Approach To Constructive Induction In Machine Learning And Data Mining -- An Overview, Marek Perkowski, Stanislaw Grygiel May 2001

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 Apr 2001

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 Mar 2001

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 Mar 2001

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 Mar 2001

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 Feb 2001

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 …


Processing Algorithms For Tracking Speckle Shifts In Optical Elastography Of Biological Tissues, Donald D. Duncan, Sean J. Kirkpatrick Jan 2001

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 Jan 2001

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 …


Assessing The Rate Of Change In The Enterprise Database System Market Over Time Using Dea, Timothy R. Anderson, Keith Hollingsworth, Lane Inman Jan 2001

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.


Rate-Matching Packet Scheduler For Real-Rate Applications, Kang Li, Jonathan Walpole, Dylan Mcnamee, Calton Pu, David Steere Jan 2001

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 …