Digital Commons Network^™

A Projection-Based Error Analysis Of Hdg Methods, Jay Gopalakrishnan, Bernardo Cockburn, Francisco-Javier Sayas

Mathematics and Statistics Faculty Publications and Presentations

We introduce a new technique for the error analysis of hybridizable discontinuous Galerkin (HDG) methods. The technique relies on the use of a new projection whose design is inspired by the form of the numerical traces of the methods. This renders the analysis of the projections of the discretization errors simple and concise. By showing that these projections of the errors are bounded in terms of the distance between the solution and its projection, our studies of influence of the stabilization parameter are reduced to local analyses of approximation by the projection. We illustrate the technique on a specific HDG …

On The Integrability Of Orthogonal Distributions In Poisson Manifolds, Daniel Fish, Serge Preston

Mathematics and Statistics Faculty Publications and Presentations

We study conditions for the integrability of the distribution defined on a regular Poisson manifold as the orthogonal complement (with respect to some (pseudo)-Riemannian metric) to the tangent spaces of the leaves of a symplectic foliation. Examples of integrability and non-integrability of this distribution are provided.

Medical Image Segmentation Using A Genetic Algorithm, Payel Ghosh

Dissertations and Theses

Advances in medical imaging technology have led to the acquisition of large number of images in different modalities. On some of these images the boundaries of key organs need to be accurately identified for treatment planning and diagnosis. This is typically performed manually by a physician who uses prior knowledge of organ shapes and locations to demarcate the boundaries of organs. Such manual segmentation is subjective, time consuming and prone to inconsistency. Automating this task has been found to be very challenging due to poor tissue contrast and ill-defined organ/tissue boundaries. This dissertation presents a genetic algorithm for combining representations …

Investigating Freeway Speed-Flow Relationships For Traffic Assignment Applications, Meead Saberi Kalaee

Dissertations and Theses

Developments in high resolution traffic sensors over the past decades are providing a wealth of empirical speed-flow data. Travel demand models use speed-flow relationships to assign traffic flows to network links. However, speed-flow relationships have not been revalidated against new detailed traffic sensor data. Therefore, it is necessary to revisit speed-flow relationships based on actual measured conditions on network links rather than assuming constant speed-flow relationships over entire highway network systems. Speed-flow relationships have been particularly difficult to calibrate and estimate when traffic volumes approach capacity, i.e. when the v/c ratio approaches one. This thesis empirically evaluates the speed-flow relationships …

Copper Thin-Film Dissolution/Precipitation Kinetics In Organic Hf Containing Cleaning Solution, Nabil George Mistkawi, Makarem A. Hussein, Malgorzata Ziomek-Moroz, Shankar B. Rananavare

Chemistry Faculty Publications and Presentations

The corrosion behavior of electrochemically deposited copper thin films in deaerated and non-deaerated commercial cleaning solution containing HF has been investigated. Thin-film copper dissolution and reaction kinetics were investigated by monitoring Cu²⁺ , employing inductively coupled plasma–mass spectroscopy, and the oxidation states of copper on Si wafer surface, employing X-ray photoelectron spectroscopy. It was determined that the reaction kinetics is first order with respect to both HF and oxygen concentrations. A kinetic scheme involving reduction of oxygen and oxidation of Cu⁰ and Cu¹⁺ is proposed, which is consistent with the experimentally determined reaction kinetic orders and the …

Comparison Of In Situ And Columnar Aerosol Spectral Measurements During Texaqs-Gomaccs 2006: Testing Parameterizations For Estimating Aerosol Fine Mode Properties, Dean B. Atkinson, Paola Massoli, Norman T. O'Neill, Patricia K. Quinn, Sarah D. Brooks, Barry Lefer

Chemistry Faculty Publications and Presentations

During the 2006 Texas Air Quality Study and Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS-GoMACCS 2006), the optical, chemical and microphysical properties of atmospheric aerosols were measured on multiple mobile platforms and at ground based stations. In situ measurements of the aerosol light extinction coefficient (σep) were performed by two multi-wavelength cavity ring-down (CRD) instruments, one located on board the NOAA R/V Ronald H. Brown (RHB) and the other located at the University of Houston, Moody Tower (UHMT). An AERONET sunphotometer was also located at the UHMT to measure the columnar aerosol optical depth (AOD). The σep data …

Creating A Sustainable And Desirable Future, Robert Costanza

Institute for Sustainable Solutions Publications and Presentations

The article suggests methods of social and economic reform as a means to counter environment impact of pollution resulting from dependence on fossil fuels.

Modeling Terahertz Diffuse Scattering From Granular Media Using Radiative Transfer Theory, Kyung Moon Nam

Dissertations and Theses

Terahertz (THz) spectroscopy can potentially be used to probe and characterize inhomogeneous materials, however spectroscopic identification of such materials from spectral features of diffuse returns is a relatively underdeveloped area of study. In this thesis, diffuse THz scattering from granular media is modeled by applying radiative transfer (RT) theory for the first time in THz sensing. Both classical RT theory and dense media radiative transfer (DMRT) theory based on the quasi-crystalline approximation (QCA) are used to calculate diffuse scattered intensity. The numerical solutions of the vector radiative transfer equations (VRTE) were coded and calculated in MATLAB. The diffuse scattered field …

Exploratory Eddy Covariance Measurements Of Surface Heat And Co2 Fluxes In The Roughness Sublayer Of An Urban Environment, Benjamin F. Burnett

Dissertations and Theses

In this study eddy covariance was used to measure sensible heat, latent heat, and carbon dioxide fluxes for the months of August, September, and October of 2009 within the roughness sublayer (RSL) of the urban center of Portland, OR. Vehicle traffic and solar radiation were also measured for the month of October. Flux measurements were compared with measurements from other urban areas as a test of reasonableness. CO₂ fluxes were nearly always positive and were strongly correlated with the weekday diurnal traffic cycle. CO₂ fluxes averaged 6.6 μmol/m^²s, which is less than other published measurements in urban areas. Sensible and …

Corrosion Behavior Of Copper Thin Films In Organic Hf-Containing Cleaning Solution For Semiconductor Applications, Nabil George Mistkawi, Makarem A. Hussein, Malgorzata Ziomek-Moroz, Shankar B. Rananavare

Chemistry Faculty Publications and Presentations

The corrosion behavior of electrochemically deposited copper thin films in deaerated and non-deaerated commercial cleaning solutions containing HF was investigated. Potentiodynamic polarization experiments were carried out to determine active, active–passive, passive, and transpassive regions. Corrosion rates were calculated from Tafel slopes. The addition of hydrogen peroxide to the solution and its influence on corrosion was also investigated by employing inductively coupled plasma-mass spectroscopy (ICP-MS) and X-ray photoelectron spectroscopy (XPS). The ICP-MS and potentiodynamic methods yielded comparable Cu dissolution rates. Surface analysis using atomic force microscopy and scanning electron microscopy, performed before and after the cleaning solution treatment, did not reveal …

Climate And More Sustainable Cities: Climate Information For Improved Planning And Management Of Cities (Producers/Capabilities Perspective), C.S.B. Grimmond, Matthias Roth, Tim R. Oke, Y. C. Au, M. Best, R. Betts, Gregory R. Carmichael, Helen Cleugh, Walter F. Dabberdt, Rohinton Emmanuel, E. Freitas, K. Fortuniak, Steven Hanna, Petra M. Klein, Laurence S. Kalkstein, C. H. Liu, Alex Nickson, David Pearlmutter, David J. Sailor, James Voogt

Mechanical and Materials Engineering Faculty Publications and Presentations

In the last two decades substantial advances have been made in the understanding of the scientific basis of urban climates. These are reviewed here with attention to sustainability of cities, applications that use climate information, and scientific understanding in relation to measurements and modelling. Consideration is given from street (micro) scale to neighbourhood (local) to city and region (meso) scale. Those areas where improvements are needed in the next decade to ensure more sustainable cities are identified. High-priority recommendations are made in the following six strategic areas: observations, data, understanding, modelling, tools and education. These include the need for more …

Solving Continuous Linear Least-Squares Problems By Iterated Projection, Ralf Juengling

Computer Science Faculty Publications and Presentations

I present a new divide-and-conquer algorithm for solving continuous linear least-squares problems. The method is applicable when the column space of the linear system relating data to model parameters is “translation invariant”. The central operation is a matrix- vector product, which makes the method very easy to implement. Secondly, the structure of the computation suggests a straightforward parallel implementation.

A complexity analysis for sequential implementation shows that the method has the same asymptotic complexity as well-known algorithms for discrete linear least-squares. For illustration we work out the details for the problem of fitting quadratic bivariate polyno- mials to a piecewise …

Pvw: Designing Virtual World Server Infrastructure, Francis Chang, C. Mic Bowman, Wu-Chi Feng

Computer Science Faculty Publications and Presentations

This paper presents a high level overview of PVW (Partitioned Virtual Worlds), a distributed system architecture for the management of virtual worlds. PVW is designed to support arbitrarily large and complex virtual worlds while accommodating dynamic and highly variable user population and content distribution density. The PVW approach enables the task of simulating and managing the virtual world to be distributed over many servers by spatially partitioning the environment into a hierarchical structure. This structure is useful both for balancing the simulation load across many nodes, as well as features such as geometric simplification and distribution of dynamic content.

Xpu: A Distributed Architecture For Metaverses, Francis Chang, C. Mic Bowman, Wu-Chi Feng

Computer Science Faculty Publications and Presentations

A significant problem of designing 3D virtual worlds (such as metaverses) is developing a scalable architecture that can manage millions of simultaneous users in an interactive 3D environment. This paper presents XPU (Extremely Partitioned Universe), a hierarchical client-server architecture for developing highly scalable metaverses. This design addresses the problem of dynamically partitioning the world to manage network and computing resources.

Solid State And Solution Dynamics Of Pyridine Based Tetraaza- Macrocyclic Lanthanide Chelates Possessing Phosphonate Ligating Functionality (Ln-Pctmb): Effect On Relaxometry And Optical Properties, Garry Kiefer, Mark Woods

Chemistry Faculty Publications and Presentations

The macrocyclic ligand 3,6,9-tris(methylenebutyl phosphonic acid)-3,6,9−15-tetraazabicyclo [9.3.1]pentadeca-1(15),11,13-triene (PCTMB) was synthesized and complexes of Eu³⁺, Tb³⁺, and Gd³⁺ studied by X-ray crystallography, luminescence, and relaxometry. In the crystal these complexes are dimeric and possess 8-coordinate Ln³⁺ centers that are linked by bridging phosphonates. The rigidity introduced by the pyridyl nucleus forces the EuPCTMB and TbPCTMB to adopt a twisted snub disphenoid (TSD) coordination geometry. Examination of the ⁵D₀ → ⁷F₀ luminescent transition of EuPCTMB in the solid state confirmed the existence of a single distinct Eu³⁺ coordination environment, whereas two …

Interview With Jim Quinn, Metro's Hazardous Waste Program, 2009 (Audio), Jim Quinn

All Sustainability History Project Oral Histories

Interview of Jim Quinn by Sean Quigley at Metro in Portland, Oregon on December 2nd, 2009.

The interview index is available for download.

Development Of A Multi-Class Bicyclist Route Choice Model Using Revealed Preference Data, Joseph Broach, John Gliebe, Jennifer Dill

Urban Studies and Planning Faculty Publications and Presentations

Existing regional travel forecasting systems are not typically set up to forecast usage of bicycle infrastructure and are insensitive to bicyclists' route preferences in general. We collected revealed preference, GPS data on 162 bicyclists over the course of several days and coded the resulting trips to a highly detailed bicycle network model. We then use these data to estimate bicyclist route choice models. As part of this research, we developed a sophisticated choice set generation algorithm based on multiple permutations of labeled path attributes, which seems to out-perform comparable implementations of other route choice set generation algorithms. The model was …

The Distribution And Reproductive Success Of The Western Snowy Plover Along The Oregon Coast - 2009, David J. Lauten, Kathleen J. Castelein, J. Daniel Farrar, Hendrik G. Herlyn, Eleanor P. Gaines

Institute for Natural Resources Publications

From 3 April – 23 September 2009 we monitored the distribution, abundance and productivity of the federally Threatened Western Snowy Plover (Charadrius alexandrinus nivosus) along the Oregon coast. From north to south, we surveyed and monitored plover activity at Sutton Beach, Siltcoos River estuary, the Dunes Overlook, North Tahkenitch Creek, Tenmile Creek, Coos Bay North Spit, Bandon Beach, New River, and Floras Lake. Our objectives for the Oregon coastal population in 2009 were to: 1) estimate the size of the adult Snowy Plover population, 2) locate plover nests, 3) continue selective use of mini-exclosures (MEs) to protect nests …

Nonparametric Inference Using Randomization And Permutation Reference Distribution And Their Monte-Carlo Approximation, Minh D. Nguyen

Dissertations and Theses

The purpose of this paper is to explain the concepts and replicate some results in the article Permutation Methods: A Basis for Exact Inference by Michael D. Ernst (2004). In the paper, we discuss how to perform nonparametric inferences using randomization and permutation reference distributions. We clearly explain the differences and similarities between the two distributions and show how to use Monte-Carlo sampling to approximate them. In the process, we introduced and proved two theorems that are the basis for some of the inferences. Specifically, one of the theorems describes the exact p-value of a two-sample test as a left-continuous …

Bringing Librarianship Back Home: Information Literacy As A Return To Method, Kimberly A. Jones

Communications in Information Literacy

Information literacy (IL) has arisen as a response to the reification of information. As information has been commodified, it has lost its fluidity as a term and an idea. Librarianship, as a result, has lost its footing, its philosophy. IL seeks to restore method to librarianship and, as a result, return subjectivity to information.

Conference Report: 5th Annual Georgia Conference On Information Literacy, Rebecca Ziegler, Mark Lewis Richardson

Communications in Information Literacy

The 5th annual Georgia Conference on Information Literacy took place in Savannah, Georgia on October 3-4, 2008. Since its inception, this conference has drawn participants from across the United States and even a few from abroad. Jointly sponsored by the Zach S. Henderson Library, the Department of Writing and Linguistics, the College of Education, and the Center for Continuing Education at Georgia Southern University, the conference offers both theoretical and practical discussions of the complex issues involved in teaching students how to find, interpret and use information in emerging electronic technologies against the backdrop of one of America's loveliest cities.

Interview With Robert Dozono, Blackfish Gallery, 2009 (Audio), Robert Dozono

All Sustainability History Project Oral Histories

Interview of Robert Dozono by Greg Plath at Blackfish Gallery in Portland, Oregon on November 21st, 2009.

The interview index is available for download.

Interview With Kimberly Holmes, 4r Sustainability, 2009 (Audio), Kimberly Holmes

All Sustainability History Project Oral Histories

Interview of Kimberly Holmes by Patrick Fausel in Portland, Oregon on November 20th, 2009.

The interview index is available for download.

Interview With Lee Michael Barrett, Eco-Logistics, 2009 (Audio), Lee Michael Barrett

All Sustainability History Project Oral Histories

Interview of Lee Michael Barrett by Angie Cirello in Portland, Oregon on November 20th, 2009.

The interview index is available for download.

Interview With Bruce Walker, Bps, 2009 (Audio), Bruce Walker

All Sustainability History Project Oral Histories

Interview of Bruce Walker by Zachary Hathaway in NW Portland on November 20th, 2009.

The interview index is available for download.

Towards Robot Theatre, Marek Perkowski

Systems Science Friday Noon Seminar Series

The talk will present the idea of futuristic robot theatre and work done towards it at the Intelligent Robotics Laboratory, Department of Electrical and Computer Engineering at PSU. After a short history of robot theatre from antiquity until 2008 we will present recent work on robot theatre in the world and at PSU, including two plays: ancient Korean folk tale "Hahoe Pylyshin" and "What's that? A Schroedinger Cat" or a debate between Einstein and Schroedinger Cat about quantum mechanics - an educational theatre. Several models of robot theatre will be discussed: animatronic theatre, interactive theatre and improvisational theatre. We will …

Interview With David Mcmahon, Cloudburst Recycling, 2009 (Audio), David Mcmahon

All Sustainability History Project Oral Histories

Interview of David McMahan by Allison Dowd at Portland State University on November 19th, 2009.

The interview index is available for download.

Interview With Peter Spendelow, Oregon Deq, 2009 (Audio), Peter Spendelow

All Sustainability History Project Oral Histories

Interview of Peter Spendelow by Angie Yzaguirre in downtown Portland, Oregon on November 17th, 2009.

The interview index is available for download.

Computer-Aided Assessment Of Diagnostic Images For Epidemiological Research, Alison G. Abraham, Donald D. Duncan, Stephen J. Gange, Sheila West

Electrical and Computer Engineering Faculty Publications and Presentations

Background: Diagnostic images are often assessed for clinical outcomes using subjective methods, which are limited by the skill of the reviewer. Computer-aided diagnosis (CAD) algorithms that assist reviewers in their decisions concerning outcomes have been developed to increase sensitivity and specificity in the clinical setting. However, these systems have not been well utilized in research settings to improve the measurement of clinical endpoints. Reductions in bias through their use could have important implications for etiologic research. Methods: Using the example of cortical cataract detection, we developed an algorithm for assisting a reviewer in evaluating digital images for the presence and …

Biological Control Of Purple Loosestrife (Lythrum Salicaria): Factors Affecting Galerucella Pusilla And Galerucella Calmariensis Establishment In Tidal Areas, Lynda Kathryn Moore

Dissertations and Theses

Galerucella pusilla and G. calmariensis have provided successful biological control of purple loosestrife (Lythrum salicaria L.) in non-tidal areas but only marginal control in areas of tidal influence. While a previous study identified mechanical scour by tidal waters as the main cause of establishment failure, purple loosestrife stem density explained more than 80% of the variability in presence and absence of Galerucella at my study sites in the Columbia River Estuary. A logistic regression model using purple loosestrife stem density, elevation, and their interaction as predictors accurately predicted 92.5% of Galerucella presence or absence observations of a test data …