Physical Sciences and Mathematics Commons^™

Analysis Of A Multigrid Algorithm For Time Harmonic Maxwell Equations, Jay Gopalakrishnan, Joseph E. Pasciak, Leszek Demkowicz

Mathematics and Statistics Faculty Publications and Presentations

This paper considers a multigrid algorithm suitable for efficient solution of indefinite linear systems arising from finite element discretization of time harmonic Maxwell equations. In particular, a "backslash" multigrid cycle is proven to converge at rates independent of refinement level if certain indefinite block smoothers are used. The method of analysis involves comparing the multigrid error reduction operator with that of a related positive definite multigrid operator. This idea has previously been used in multigrid analysis of indefinite second order elliptic problems. However, the Maxwell application involves a nonelliptic indefinite operator. With the help of a few new estimates, the …

A Characterization Of Hybridized Mixed Methods For Second Order Elliptic Problems, Bernardo Cockburn, Jay Gopalakrishnan

Mathematics and Statistics Faculty Publications and Presentations

In this paper, we give a new characterization of the approximate solution given by hybridized mixed methods for second order self-adjoint elliptic problems. We apply this characterization to obtain an explicit formula for the entries of the matrix equation for the Lagrange multiplier unknowns resulting from hybridization. We also obtain necessary and sufficient conditions under which the multipliers of the Raviart–Thomas and the Brezzi–Douglas–Marini methods of similar order are identical.

Decentralized Control Of Vehicle Formations, Gerardo Lafferriere, Anca Williams, John S. Caughman Iv, J. J. P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

This paper investigates a method for decentralized stabilization of vehicle formations using techniques from algebraic graph theory. The vehicles exchange information according to a pre-specified communication digraph, G. A feedback control is designed using relative information between a vehicle and its in-neighbors in G. We prove that a necessary and sufficient condition for an appropriate decentralized linear stabilizing feedback to exist is that G has a rooted directed spanning tree. We show the direct relationship between the rate of convergence to formation and the eigenvalues of the (directed) Laplacian of G. Various special situations are discussed, including …

Directed Extended Dependency Analysis For Data Mining, Thaddeus T. Shannon, Martin Zwick

Systems Science Faculty Publications and Presentations

Extended dependency analysis (EDA) is a heuristic search technique for finding significant relationships between nominal variables in large data sets. The directed version of EDA searches for maximally predictive sets of independent variables with respect to a target dependent variable. The original implementation of EDA was an extension of reconstructability analysis. Our new implementation adds a variety of statistical significance tests at each decision point that allow the user to tailor the algorithm to a particular objective. It also utilizes data structures appropriate for the sparse data sets customary in contemporary data mining problems. Two examples that illustrate different approaches …

An Overview Of Reconstructability Analysis, Martin Zwick

Systems Science Faculty Publications and Presentations

This paper is an overview of reconstructability analysis (RA), a discrete multivariate modeling methodology developed in the systems literature; an earlier version of this tutorial is Zwick (2001). RA was derived from Ashby (1964), and was developed by Broekstra, Cavallo, Cellier Conant, Jones, Klir, Krippendorff, and others (Klir, 1986, 1996). RA resembles and partially overlaps log‐line (LL) statistical methods used in the social sciences (Bishop et al., 1978; Knoke and Burke, 1980). RA also resembles and overlaps methods used in logic design and machine learning (LDL) in electrical and computer engineering (e.g. Perkowski et al., 1997). Applications of RA, like …

Reversible Modified Reconstructability Analysis Of Boolean Circuits And Its Quantum Computation, Anas Al-Rabadi, Martin Zwick

Systems Science Faculty Publications and Presentations

Modified Reconstructability Analysis (MRA) can be realized reversibly by utilizing Boolean reversible (3,3) logic gates that are universal in two arguments. The quantum computation of the reversible MRA circuits is also introduced. The reversible MRA transformations are given a quantum form by using the normal matrix representation of such gates. The MRA-based quantum decomposition may play an important role in the synthesis of logic structures using future technologies that consume less power and occupy less space.

Reconstructability Analysis With Fourier Transforms, Martin Zwick

Systems Science Faculty Publications and Presentations

Fourier methods used in two‐ and three‐dimensional image reconstruction can be used also in reconstructability analysis (RA). These methods maximize a variance‐type measure instead of information‐theoretic uncertainty, but the two measures are roughly collinear and the Fourier approach yields results close to that of standard RA. The Fourier method, however, does not require iterative calculations for models with loops. Moreover, the error in Fourier RA models can be assessed without actually generating the full probability distributions of the models; calculations scale with the size of the data rather than the state space. State‐based modeling using the Fourier approach is also …

A Software Architecture For Reconstructability Analysis, Kenneth Willett, Martin Zwick

Systems Science Faculty Publications and Presentations

Software packages for reconstructability analysis (RA), as well as for related log linear modeling, generally provide a fixed set of functions. Such packages are suitable for end‐users applying RA in various domains, but do not provide a platform for research into the RA methods themselves. A new software system, Occam3, is being developed which is intended to address three goals which often conflict with one another to provide: a general and flexible infrastructure for experimentation with RA methods and algorithms; an easily‐configured system allowing methods to be combined in novel ways, without requiring deep software expertise; and a system which …

Modified Reconstructability Analysis For Many-Valued Functions And Relations, Anas Al-Rabadi, Martin Zwick

Systems Science Faculty Publications and Presentations

A novel many-valued decomposition within the framework of lossless Reconstructability Analysis is presented. In previous work, Modified Recontructability Analysis (MRA) was applied to Boolean functions, where it was shown that most Boolean functions not decomposable using conventional Reconstructability Analysis (CRA) are decomposable using MRA. Also, it was previously shown that whenever decomposition exists in both MRA and CRA, MRA yields simpler or equal complexity decompositions. In this paper, MRA is extended to many-valued logic functions, and logic structures that correspond to such decomposition are developed. It is shown that many-valued MRA can decompose many-valued functions when CRA fails to do …

State-Based Reconstructability Analysis, Martin Zwick, Michael S. Johnson

Systems Science Faculty Publications and Presentations

Reconstructability analysis (RA) is a method for detecting and analyzing the structure of multivariate categorical data. While Jones and his colleagues extended the original variable‐based formulation of RA to encompass models defined in terms of system states, their focus was the analysis and approximation of real‐valued functions. In this paper, we separate two ideas that Jones had merged together: the “g to k” transformation and state‐based modeling. We relate the idea of state‐based modeling to established variable‐based RA concepts and methods, including structure lattices, search strategies, metrics of model quality, and the statistical evaluation of model fit for analyses based …

Compositional And Mineralogical Relationships Between Mafic Inclusions And Host Lavas As Key To Andesite Petrogenesis At Mount Hood Volcano, Oregon, Melinda Michelle Woods

Dissertations and Theses

Throughout its eruptive history, Mount Hood has produced compositionally similar calc-alkaline andesite as lava flows and domes near the summit and basaltic andesitic flows from flank vents. Found within the andesite are slightly more mafic inclusions that are compositionally similar to the host andesite (or host lavas); no inclusions were found in the flank lavas. Host lavas and inclusions have the following mineral assemblage: plag + opx ± cpx ± amp + oxides. Flank lava mineralogy is similar to the inclusions and host lavas, but since they are more mafic they contain olivine instead of amphibole. Average silica content among …

Pperfgrid: A Grid Services-Based Tool For The Exchange Of Heterogeneous Parallel Performance Data, John Jared Hoffman

Dissertations and Theses

This thesis details the approach taken in developing PPerfGrid. Section 2 discusses other research related to this project. Section 3 provides general background on the technologies utilized in PPerfGrid, focusing on the components that make up the Grid services architecture. Section 4 provides a description of the architecture of PPerfGrid. Section 5 details the implementation of PPerfGrid. Section 6 presents tests designed to measure the overhead and scalability of the PPerfGrid application. Section 7 suggests future work, and Section 8 concludes the thesis.

Willamette River Basin Temperature Tmdl Model: Boundary Conditions And Model Setup, Robert Leslie Annear, Michael Lee Mckillip, Sher Jamal Khan, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The State of Oregon Department of Environmental Quality (DEQ) is developing a TMDL for temperature in the Willamette River basin shown in Figure 1. The study area included the Willamette River and all major tributaries (except the Tualatin River where a TMDL process was already concluded). A large section of the Columbia River was also modeled to provide adequate boundary representation of tidal flows in the lower Willamette River. The Willamette River below the Oregon City Falls in the Portland metropolitan area has a typical diurnal tidal range of 1 m. The development of a dynamic model of temperature and …

Infrastructure For Performance Tuning Mpi Applications, Kathryn Marie Mohror

Dissertations and Theses

Clusters of workstations are becoming increasingly popular as a low-budget alternative for supercomputing power. In these systems,message-passing is often used to allow the separate nodes to act as a single computing machine. Programmers of such systems face a daunting challenge in understanding the performance bottlenecks of their applications. This is largely due to the vast amount of performance data that is collected, and the time and expertise necessary to use traditional parallel performance tools to analyze that data.

The goal of this project is to increase the level of performance tool support for message-passing application programmers on clusters of workstations. …

Environmental Gradients, Community Boundaries, And Disturbance The Darlingtonia Fens Of Southwestern Oregon, Deborah A. Tolman

Dissertations and Theses

The Darlingtonia fens, found on serpentine soils in southern Oregon, are distinct communities that frequently undergo dramatic changes in size and shape in response to a wide array of environmental factors. Since few systems demonstrate a balance among high water tables, shallow soils, the presence of heavy metals, and limited nutrients, conservative efforts have been made to preserve them. This dissertation investigates the role of fire on nutrient cycling and succession in three separate fens, each a different time since fire. I specifically analyze the spatial distributions of soil properties, the physical and ecological characteristics of ecotones between Jeffrey pine …

Current Perspectives On Energy And Mass Fluxes In Volcanic Arcs, William Leeman, Jon Davidson, Tobias Fischer, Anita Grunder, Mark Reagan, Martin J. Streck

Geology Faculty Publications and Presentations

Volcanoes of the Pacific Ring of Fire and other convergent margins worldwide are familiar manifestations of nature's energy, account for about 25% of global volcanic outputs, dominate volcanic gas emissions to the atmosphere, and pose significant physical threats to a large human population. Yet the processes behind this prolific activity remain poorly understood.

An international "State of the Arc" (SOTA) conference was held in August on the slopes of Mt. Hood, Oregon, to address current views on the energy and mass fluxes in volcanic arcs. This meeting brought together some 90 leading experts and students of subduction zones and their …

Using Dynamic Optimization For Control Of Real Rate Cpu Resource Management Applications, Varin Vahia, Ashvin Goel, David Steere, Jonathan Walpole, Molly H. Shor

Computer Science Faculty Publications and Presentations

In this paper we design a proportional-period optimal controller for allocating CPU to real rate multimedia applications on a general-purpose computer system. We model this computer system problem in to state space form. We design a controller based on dynamic optimization LQR tracking techniques to minimize short term and long term time deviation from the current time stamp and also CPU usage. Preliminary results on an experimental set up are encouraging.

Integrated Hydrologic And Hydrochemical Observations Of Hidden Creek Lake Jökulhlaups, Kennicott Glacier, Alaska, Suzanne P. Anderson, Joseph S. Walder, Robert S. Anderson, Erin R. Kraal, Michelle Cunico, Andrew G. Fountain, Dennis C. Trabant

Geology Faculty Publications and Presentations

Hidden Creek Lake (HCL), an ice-marginal lake impounded by Kennicott Glacier, Wrangell Mountains, Alaska, fills annually to ~20 to 30 x ~10⁶ m³ and then drains subglacially within 2 to 3 days. During the 1999 and 2000 jökulhlaups, we carried out a series of planned observations around the lake and in the Kennicott River, which drains the glacier. Approximately 20% of the lake volume was contained within a subglacial water ‘‘wedge’’ beneath the ice dam. The entire volume of the lake drains through the wedge; hydraulic head loss through this constriction may be responsible for the fairly symmetrical shape of …

Pressure-Induced Insulating State In An Organic Superconductor, Gary L. Gard, Javid Mohtasham, J. A. Schlueter, C. Pfleiderer, J. Wosnitza, J. Hagel

Chemistry Faculty Publications and Presentations

The electronic-transport properties of the quasi-two-dimensional organic superconductor β″–(BEDT-TTF)₂SF₅CH₂CF₂SO₃, where BEDT-TTF stands for bisethylenedithio-tetrathiafulvalene, have been investigated in magnetic fields up to 15 T and under hydrostatic pressure up to about 14 kbars. Shubnikov–de Haas data reveal a nonmonotonic pressure dependence of the holelike Fermi surface, a roughly linear increase of the electron g factor, and an approximately linear decrease of the cyclotron effective mass. By assuming that the latter reflects the pressure-induced reduction of the superconducting coupling parameter λ the rapid reduction of the superconducting transition temperature Tc(p) can be reasonably well described by the modified McMillan equation. Above …

A Browser For Incremental Programming, Andrew P. Black

Computer Science Faculty Publications and Presentations

Much of the elegance and power of Smalltalk comes from its programming environment and tools. First introduced more than 20 years ago, the Smalltalk browser enables programmers to “home in” on particular methods using a hierarchy of manually-defined classifications. By its nature, this classification scheme says a lot about the desired state of the code, but little about the actual state of the code as it is being developed. We have extended the Smalltalk browser with dynamically computed virtual categories that dramatically improve the browser’s support for incremental programming. We illustrate these improvements by example, and describe the algorithms used …

Adaptive Live Video Streaming By Priority Drop, Jie Huang, Charles Krasic, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we explore the use of Priority-progress streaming (PPS) for video surveillance applications. PPS is an adaptive streaming technique for the delivery of continuous media over variable bit-rate channels. It is based on the simple idea of reordering media components within a time window into priority order before transmission. The main concern when using PPS for live video streaming is the time delay introduced by reordering. In this paper we describe how PPS can be extended to support live streaming and show that the delay inherent in the approach can be tuned to satisfy a wide range of …

Using Reconstructability Analysis To Select Input Variables For Artificial Neural Networks, Stephen Shervais, Martin Zwick

Systems Science Faculty Publications and Presentations

We demonstrate the use of Reconstructability Analysis to reduce the number of input variables for a neural network. Using the heart disease dataset we reduce the number of independent variables from 13 to two, while providing results that are statistically indistinguishable from those of NNs using the full variable set. We also demonstrate that rule lookup tables obtained directly from the data for the RA models are almost as effective as NNs trained on model variables.

A System Dynamics Model Of The Pacific Coast Rockfish Fishery, Wayne Wakeland, Olgay Cangur, Guillermo Rueda, Astrid Scholz

Systems Science Faculty Publications and Presentations

This paper presents a model of the dynamic behavior of the yellowtail rockfish of the Pacific Coast of the United States. The purpose of the model is to generate endogenously the historical data for fish population, fishing vessels, regulatory parameters, and fish harvest. The model was subjected to a variety of tests to determine its sensitivity to changes in key parameters and initial values, including extreme conditions. Model results indicate that acceptable biological catch and fleet capacity must be adjusted quickly in response to changing conditions, in order to improve fishery sustainability. Additional analysis reinforces the policy of setting the …

Vertical Nanowire Transistor In Flexible Polymer Foil, Jie Chen, Rolf Könenkamp

Physics Faculty Publications and Presentations

Fabrication and operation of a vertical nanowire field-effect transistor is reported. The device is prepared by growing vertical wires in the cylindrical pores of a polymer foil stack. The nanowirediameter is approximately 100 nm, the packing density up to 10⁸ cm⁻². The polymer foil stack consists of two polymer layers and an intermediate metal layer. Cylindrical holes are prepared in this stack by using fast ion irradiation and subsequent etching. Well-defined cylindrical openings with diameters between 50 and 150 nm are obtained. The semiconductor growth involves electrodeposition of the p-type quaternary compound CuSCN. Electrical measurements on first devices show transistor …

Morphological Biosignatures And The Search For Life On Mars, Sherry L. Cady, Jack D. Farmer, John P. Grotzinger, J. William Schopf, Andrew Steele

Geology Faculty Publications and Presentations

This report provides a rationale for the advances in instrumentation and understanding needed to assess claims of ancient and extraterrestrial life made on the basis of morphological biosignatures. Morphological biosignatures consist of bona fide microbial fossils as well as microbially influenced sedimentary structures. To be recognized as evidence of life, microbial fossils must contain chemical and structural attributes uniquely indicative of microbial cells or cellular or extracellular processes. When combined with various research strategies, high-resolution instruments can reveal such attributes and elucidate how morphological fossils form and become altered, thereby improving the ability to recognize them in the geological record …

Linearized Stability Analysis Of Accelerated Planar And Spherical Fluid Interfaces With Slow Compression, John D. Ramshaw, Peter A. Amendt

Physics Faculty Publications and Presentations

We present linearized stability analyses of the effect of slow anisotropic compression or expansion on the growth of perturbations at accelerated fluid interfaces in both planar and spherical geometries. The interface separates two fluids with different densities, compressibilities, and compression rates. We show that a perturbation of large mode number on a spherical interface grows at precisely the same rate as a similar perturbation on a planar interface subjected to the same normal and transverse compression rates.

Psf Measurements On Back-Illuminated Ccds, Ralf Widenhorn, Alexander Weber, Morley M. Blouke, Albert J. Bae, Erik Bodegom

Physics Faculty Publications and Presentations

The spatial resolution of an optical device is generally characterized by either the Point Spread Function (PSF) or the Modulation Transfer Function (MTF). To directly obtain the PSF one needs to measure the response of an optical system to a point light source. We present data that show the response of a back-illuminated CCD to light emitted from a sub-micron diameter glass fiber tip. The potential well in back-illuminated CCD"s does not reach all the way to the back surface. Hence, light that is absorbed in the field-free region generates electrons that can diffuse into other pixels. We analyzed the …

Glaciers Of The Mcmurdo Dry Valleys: Terrestrial Analog For Martian Polar Sublimation, Andrew G. Fountain, J. S. Kargel, Karen J. Lewis, D. R. Macayeal

Geography Faculty Publications and Presentations

The surfaces of the Martian north and south polar residual caps are marked by unusual ice features: dark spiralesque troughs up to 1 km deep, 10 km wide and 300 km long appear on both ice caps, and circular pits that make up the “Swiss-cheese” terrain appear on the south polar cap. Both types of features are of interest to researchers as a potential means of understanding ice composition and flow rates. Some glaciers of the McMurdo Dry Valleys have surface features unknown elsewhere on terrestrial glaciers, including canyons over 6 km long, 100 m wide, and tens of meters …

Upper Spokane River Model In Idaho: Boundary Conditions And Model Setup For 2001, Scott A. Wells, Robert Leslie Annear, Chris Berger

Civil and Environmental Engineering Faculty Publications and Presentations

The Spokane River in Idaho originates in Coeur d’Alene Lake (Figure 1 and Figure 2). The section of the Spokane River from Coeur d’Alene Lake to the Washington state line is the subject of a water quality study for the US Environmental Protection Agency. The objective of this study is to create a water quality and hydrodynamic model of the Spokane River in Idaho using CE-QUAL-W2 Version 3.1 (Cole and Wells, 2002).

Since the Spokane River is water quality limited, a hydrodynamic and water quality model for the Spokane River in Washington was developed by Portland State University for the …

Watershed Data Organization And Project Prioritization, Joshua Darling

Environmental Science and Management Professional Master's Project Reports

The Oregon Coastal Salmon Restoration Initiative (OCSRI) (1197) is the first of several documents that have come to be known as the Oregon Plan for Salmon and watersheds (OPSW). The OCSRI indicates that protection and restoration of salmonid stocks and improvement in water quality are the main roles for state agencies within the Oregon Plan (EO09-01: 1(b)). The Oregon Plan specifies particular actions that state agencies must take to aid in salmon recovery and also directs the Governors Watershed Enhancement Board (GWEB) to help create and organize watershed councils responsible for assessing conditions and determining priorities for watershed health. A …