Digital Commons Network^™

Nonlinear Ordinary Differential Equations In Fluid Dynamics, John D. Ramshaw

Physics Faculty Publications and Presentations

The equivalence between nonlinear ordinary differential equations (ODEs) and linear partial differential equations (PDEs) was recently revisited by Smith, who used the equivalence to transform the ODEs of Newtonian dynamics into equivalent PDEs, from which analytical solutions to several simple dynamical problems were derived. We show how this equivalence can be used to derive a variety of exact solutions to the PDEs describing advection in fluid dynamics in terms of solutions to the equivalent ODEs for the trajectories of Lagrangian fluid particles. The PDEs that we consider describe the time evolution of non-diffusive scalars, conserved densities, and Lagrangian surfaces advected …

The Distribution And Reproductive Success Of The Western Snowy Plover Along The Oregon Coast - 2011, David J. Lauten, Kathleen J. Castelein, J. Daniel Farrar, Adam A. Kotaich, Eleanor P. Gaines

Institute for Natural Resources Publications

From 6 April – 19 September 2011 we monitored the distribution, abundance and productivity of the federally Threatened Western Snowy Plover (Charadrius nivosus 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 2011 were to: 1) estimate the size of the adult Snowy Plover population, 2) locate plover nests, 3) continue use of mini-exclosures (MEs) to protect nests from …

Application Of Genetic Algorithm For Synthesis Of Large Reversible Circuits Using Covered Set Partitions, Maher Mofeid Hawash, Baker Abdalhaq, Amjad Hawash, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

We present the results of application of Evolutionary Algorithms to the problem of synthesizing quantum circuits which belong to the class of reversible circuits, represented as an input/output mapping vectors. The paper specifically focuses on large quantum circuits where many valid solutions exist in an exponentially inflating search space. Valid solutions represent the set of all input vector permutations (arrangements) which satisfy the circuit specification. The search space for circuits with large number of variables grows exponentially making it impossible to discover the set of optimal solutions. The paper compares three methods for selecting valid solutions of input vector sequences: …

Ensemble Methods For Dynamic Data Assimilation Of Chemical Observations In Atmospheric Models, Adrian Sandu, Emil Constantinescu, Gregory R. Carmichael, Tianfeng Chai, Dacian Daescu, John H. Seinfeld

Mathematics and Statistics Faculty Publications and Presentations

The task of providing an optimal analysis of the state of the atmosphere requires the development of dynamic data-driven systems (DDDAS) that efficiently integrate the observational data and the models. Data assimilation, the dynamic incorporation of additional data into an executing application, is an essential DDDAS concept with wide applicability. In this paper we discuss practical aspects of nonlinear ensemble Kalman data assimilation applied to atmospheric chemical transport models. We highlight the challenges encountered in this approach such as filter divergence and spurious corrections, and propose solutions to overcome them, such as background covariance inflation and filter localization. The predictability …

Reliable A-Posteriori Error Estimators For Hp-Adaptive Finite Element Approximations Of Eigenvalue/Leigenvector Problems, Stefano Giani, Luka Grubisic, Jeffrey S. Ovall

Mathematics and Statistics Faculty Publications and Presentations

We present reliable a-posteriori error estimates for hp-adaptive finite element approxima- tions of eigenvalue/eigenvector problems. Starting from our earlier work on h adaptive finite element approximations we show a way to obtain reliable and efficient a-posteriori estimates in the hp-setting. At the core of our analysis is the reduction of the problem on the analysis of the associated boundary value problem. We start from the analysis of Wohlmuth and Melenk and combine this with our a-posteriori estimation framework to obtain eigenvalue/eigenvector approximation bounds.

Raps Sheet, December 2011, Retirement Association Of Portland State

RAPS Sheet: Monthly Newsletter

No abstract provided.

The Theory And Practice Of Genetically Engineered Crops And Agricultural Sustainability, David E. Ervin, Leland L. Glenna, Raymond Adelard Jussaume

Institute for Sustainable Solutions Publications and Presentations

The development of genetically engineered (GE) crops has focused predominantly on enhancing conventional pest control approaches. Scientific assessments show that these GE crops generally deliver significant economic and some environmental benefits over their conventional crop alternatives. However, emerging evidence indicates that current GE crops will not foster sustainable cropping systems unless the negative environmental and social feedback effects are properly addressed. Moreover, GE crop innovations that promote more sustainable agricultural systems will receive underinvestment by seed and chemical companies that must understandably focus on private returns for major crops. Opportunities to promote crops that convey multi-faceted benefits for the environment …

Defining Conservation Priorities For Freshwater Fishes According To Taxonomic, Functional, And Phylogenetic Diversity, Angela L. Strecker, Julian D. Olden, Joanna B. Whittier, Craig Patrick Paukert

Environmental Science and Management Faculty Publications and Presentations

To date, the predominant use of systematic conservation planning has been to evaluate and conserve areas of high terrestrial biodiversity. Although studies in freshwater ecosystems have received recent attention, research has rarely considered the potential trade-offs between protecting different dimensions of biodiversity and the ecological processes that maintain diversity. We provide the first systematic prioritization for freshwaters (focusing on the highly threatened and globally distinct fish fauna of the Lower Colorado River Basin, USA) simultaneously considering scenarios of: taxonomic, functional, and phylogenetic diversity; contemporary threats to biodiversity (including interactions with nonnative species); and future climate change and human population growth. …

A Review On Convolutions Of Gamma Random Variables, Baha-Eldin Khaledi, Subhash C. Kochar

Mathematics and Statistics Faculty Publications and Presentations

Due to its wide range of applications, the topic of the distribution theory of convolutions of Gamma random variables has attracted the attention of many researchers. In this paper we review some of the latest developments on this problem.

Aquatic Plant Surveys In The Bureau Of Land Management, Medford District, 2010-2011, Mark D. Sytsma, Rich Miller, Vanessa Morgan

Center for Lakes and Reservoirs Publications and Presentations

The introduction of invasive aquatic plant species (IAPS) can cause significant ecological and economic harm. IAPS can displace native aquatic plant species, impair recreation, and degrade water quality. Early detection of new invasions can improve chances for successful eradication or containment to reduce the risk of IAPS spread. The Oregon Department of Agriculture (ODA) lists the most egregious offenders as “Noxious Weeds” which are defined as plants classified by the Oregon State Weed Board that are injurious to public health, agriculture, recreation, wildlife, or any public or private property (ODA 2011).

Several IAPS classified as noxious have been detected within …

Information Literacy For Multiple Disciplines: Toward A Campus-Wide Integration Model At Indiana University, Bloomington, Brian Winterman, Carrie Donovan, Rachel Slough

Communications in Information Literacy

Within disciplines are a set of shared values and thought processes that students must master in order to become participants of that discipline. Information literacy as defined by the ACRL is a set of standards and principles that can apply to all disciplines. In order to produce information literate undergraduates in a given discipline, information literacy standards must be integrated with the values and processes of the discipline. In this study, librarians partnered with faculty in gender studies and molecular biology to integrate information literacy with courses in those areas. Student performance and attitudes improved as a result of the …

Biomimetic Broadband Antireflection Gratings On Solar-Grade Multicrystalline Silicon Wafers, Blayne M. Phillips, Peng Jiang, Bin Jiang

Mathematics and Statistics Faculty Publications and Presentations

The authors report a simple and scalable bottom-up technique for fabricating broadband antireflection gratings on solar-grade multicrystalline silicon (mc-Si) wafers. A Langmuir-Blodgett process is developed to assemble close-packed silica microspheres on rough mc-Si substrates. Subwavelength moth-eye pillars can then be patterned on mc-Si by using the silica microspheres as structural template. Hemispherical reflectance measurements show that the resulting mc-Si gratings exhibit near zero reflection for a wide range of wavelengths. Both experimental results and theoretical prediction using a rigorous coupled-wave analysis model show that close-packed moth-eye arrays exhibit better antireflection performance than non-close-packed arrays due to a smoother refractive index …

Changing The Way We View Humanity And The Rest Of Nature, Robert Costanza

Institute for Sustainable Solutions Publications and Presentations

An introduction is presented in which the editor discusses various reports within the issue on topics including the idea of ecosystem services, how ecosystem aided to solve the mother of all problems and how ecosystem services offer real solutions to problems.

A Global Partnership For Ecosystem Services, Dolf De Groot, Robert Costanza, Dieter Van Den Broeck, James Aronson

Institute for Sustainable Solutions Publications and Presentations

The article offers information on the participation of the Baviaanskloof Mega Reserve in the Ecosystem Services Partnership (ESP) in South Africa. It mentions that an active group of scientists has been working with the local and ESP to restore the Mega Reserve using the ecosystem services. The group combines a learning village to raise awareness of the project and a tree nursery that specializes in indigenous species.

Indigenous Australians Fight Climate Change With Fire, Scott Heckbert, Jeremy Russell-Smith, Andrew Reeson, Glenn James

Institute for Sustainable Solutions Publications and Presentations

The article focuses on the move of Indigenous people in Australia to implement fire management in an effort to improve landscape condition and reduce greenhouse gas emissions. It highlights the launch of the West Arnhem Land Fire Abatement (WALFA) project, a prime example of scientists, governments, Indigenous land managers, and carbon markets connecting to offer innovative solutions to resource management and economic development. It also highlights ecosystem services in the region.

The Relationship Between Vmt And Economic Activity, B. Starr Mcmullen, Nathan Eckstein

TREC Final Reports

Vehicle miles traveled (VMT) in the U.S. have exhibited an upward trend over time similar to that observed for gross domestic product (GDP) and personal income (PI). While conventional wisdom suggests that economic growth leads to more driving and thus higher VMT, it is theoretically possible that the causation could also be the other way around. If causation is from VMT to GDP, then legislation such as the Federal Surface Transportation Policy and Planning Act of 2009’s directive to annually reduce national per capita VMT could potentially have an adverse impact on overall economic activity.

This study uses times series …

Design Of A Dynamic Activity Travel Modeling System For Metro, John Gliebe

Urban Studies and Planning Faculty Publications and Presentations

Trip-based models are no longer adequate for some of the more complex questions. They fail to account for time of day sensitivity, dynamic congestion effects, variable pricing and tolls, and the reliability of both highways and transit. Existing activity/tour-based models lack the enhanced temporal element provided by a more dynamic, activity-based microsimulation. DASH is the next-generation model being developed by the Metro Research Center.

Refining Greenstep: Impacts Of Vehicle Technologies And Its/Operational Improvements On Travel Speed And Fuel Consumption Curves, Kelly Clifton, Alexander Y. Bigazzi

Civil and Environmental Engineering Faculty Publications and Presentations

This report describes analysis undertaken to establish a method for incorporating traffic operations and ITS strategies into the GreenSTEP model. We first discuss operations impacts on fuel economy and delay from the literature. Then, an investigation of delay adjustments in GreenSTEP shows that different methods of representing delay changes lead to similar (and small) impacts on fuel economy. From this result we establish average speed adjustment by congestion level as the preferred method for incorporating delay effects from operations improvements. An investigation of aggregate traffic operations impacts produces estimates of base speeds without operations improvements, maximum speeds with full operational …

2011 Aquatic Weed Surveys In Timothy Lake, Lake Harriet And North Fork Reservoir : Final Report, Mark D. Sytsma, Vanessa Howard Morgan

Center for Lakes and Reservoirs Publications and Presentations

Portland General Electric (PGE) was issued a new license by the Federal Energy Regulatory Commission (FERC) for the continued operation and maintenance of the Clackamas River Hydroelectric Project No. 2195 (Project) on December 21, 2010. This Project is located on both the lower 16 miles of Oak Grove Fork of the Clackamas River (Oak Grove Fork) and the mainstem of the Clackamas River in Clackamas County, Oregon. The effects of relicensing this Project were addressed in the Final Environmental Impact Statement (FEIS) completed in December 2006 and included the issue of invasive aquatic weed species. The term “aquatic weed” is …

Historical Vegetation Of Central Southwest Oregon, Based On Glo Survey Notes : Final Report To Usdi Bureau Of Land Management, Medford District, O. Eugene Hickman, John A. Christy

Institute for Natural Resources Publications

Historical vegetation at the time of European settlement is of great interest to both the public and land managers, but is poorly documented. One source of data are the earliest land survey records of the General Land Office (GLO). Rectangular township surveys in Southwest Oregon were initiated in the mid 1850’s as settlers began to claim homesteads in the Bear Creek Valley surrounding what is now Medford. We examined GLO land survey field notes and plats (maps) accompanying the surveys, transcribed GLO landscape data into an Access database, and classified the data set into very general vegetation types for mapping. …

Frequency Multiplication In Nanowires, Marius Ghita, Ed Godshalk, Gary Goncher, Raj Solanki

Physics Faculty Publications and Presentations

Frequency multiplication in silicon and ZnO nanowire based Schottky and p-n diodes has been demonstrated at fundamental frequencies of 70 MHz and 500 MHz. Our motivation for using nanowires contacted at their tips was to minimize the spreading resistance and boundary capacitance in order to produce higher cut-off frequencies and conversion efficiencies compared to planar diodes. The data presented here are limited to the lower GHz range by the frequency response of the experimental apparatus. However, by employing microwave waveguides and higher fundamental source frequencies, it should be possible to reach much higher output frequencies with nanowire-based diodes.

Field Programmable Gate Array Based Reconfigurable Scanning Probe/Optical Microscope, Derek Brant Nowak, Andrew James Lawrence, Zechariah K. Dzegede, Justin C. Hiester, Cliff Kim, Erik J. Sánchez

Physics Faculty Publications and Presentations

The increasing popularity of nanometrology and nanospectroscopy has pushed researchers to develop complex new analytical systems. This paper describes the development of a platform on which to build a microscopy tool that will allow for flexibility of customization to suit research needs. The novelty of the described system lies in its versatility of capabilities. So far, one version of this microscope has allowed for successful near-field and far-field fluorescence imaging with single molecule detection sensitivity. This system is easily adapted for reflection, polarization (Kerr magneto-optical (MO)), Raman, super-resolution techniques, and other novel scanning probe imaging and spectroscopic designs. While collecting …

A Simple Approach To Neutral Atom Microscopy, Philip Witham, Erik J. Sánchez

Physics Faculty Publications and Presentations

Scanning surfaces using a beam of noncharged atoms or molecules allows for especially nondestructive and low-energy surface imaging, with the potential to obtain new information about surfaces that cannot be easily obtained otherwise. We have developed a new approach, operating with the sample at a close working distance from an aperture, the need for optics to focus the beam is obviated. Compared to more complex approaches, the theoretical performance has no other disadvantage than the short working distance. Resolution of 1.5 μm has been achieved, and submicron resolution appears to be practical. Construction of the microscope and results are presented, …

Dr7a: Changes In Ecosystem Services And Migration In Low-Lying Coastal Areas Over The Next 50 Years, Robert Costanza, Ida Kubiszewski, Joe Roman, Paul Sutton

Institute for Sustainable Solutions Publications and Presentations

This paper examines the history and current status of ecosystem services in low-lying coastal areas (LLCAs), their potential changes because of wider environmental and social shifts, and the potential impacts of these changes on human migration. We synthesised information from a number of sources on the status and value of ecosystem services in LLCAs, including information about key ecosystems that are likely to be particularly vulnerable to environmental change. We created maps of ecosystem and human population changes in LLCAs and then estimated changes in ecosystem services. Estimating the impacts of these potential changes depends on the future scenario one …

Integrating Ecosystem Services, River Restoration And Community: A Case Study At Fisher's Bend, Michael Carlson

Environmental Science and Management Professional Master's Project Reports

Natural areas and ecosystem services at the edge of urban areas are threatened by increasing development. This paper examines how community based restoration partnerships can work to identify, protect and restore ecosystem services provided by salmon and our local rivers. Floodplains provide a wide range of ecosystem services to urban and rural communities and we should work collaboratively to protect and restore them. Floodplains are especially valuable and important for salmon recovery. By using a case study, we explore the process and feasibility of restoring off-channel salmon habitat at Fisher's Bend in the lower Clackamas river. A feasibility study was …

Green And Economic Fleet Replacement Modeling: Part I, David S. Kim, Miguel A. Figliozzi, J. David Porter

TREC Final Reports

The purpose of this study was to gain a better understanding of how equipment replacement decisions are supported with data collection and quantitative models at state DOTs, and to determine if models found in the research literature offer any better decision support when applied to realistic fleet usage and cost data. This study also addressed the current state of equipment replacement at state DOTs with respect to using measurable “green” criteria in replacement decisions, and the development of new quantitative replacement models utilizing such criteria. The responses from 25 state DOTs indicates that there is little consistency in the criteria …

Value Of Travel-Time Reliability: Commuters’ Route-Choice Behavior In The Twin Cities, Carlos Carrion-Madera, David Levinson, Kathleen Harder, Miguel A. Figliozzi

TREC Final Reports

Travel-time variability is a noteworthy factor in network performance. It measures the temporal uncertainty experienced by users in their movement between any two nodes in a network. The importance of the time variance depends on the penalties incurred by the users. In road networks, travelers consider the existence of this journey uncertainty in their selection of routes. This choice process takes into account travel-time variability and other characteristics of the travelers and the road network. In this complex behavioral response, a feasible decision is spawned based on not only the amalgamation of attributes, but also on the experience travelers incurred …

The Influence Of Land Use And Climate Change On Forest Biomass And Composition In Massachusetts, Usa, Jonathan R. Thompson, David R. Foster, Robert M. Scheller, David Kittridge

Environmental Science and Management Faculty Publications and Presentations

Land use and climate change have complex and interacting effects on naturally dynamic forest landscapes. To anticipate and adapt to these changes, it is necessary to understand their individual and aggregate impacts on forest growth and composition. We conducted a simulation experiment to evaluate regional forest change in Massachusetts, USA over the next 50 years (2010–2060). Our objective was to estimate, assuming a linear continuation of recent trends, the relative and interactive influence of continued growth and succession, climate change, forest conversion to developed uses, and timber harvest on live aboveground biomass (AGB) and tree species composition. We examined 20 …

The Social Nature Of Male Suicide: A New Analytic Model, Daniel Coleman, John T. Casey

School of Social Work Faculty Publications and Presentations

Suicide is one of the leading causes of male mortality. In nearly every country in the world, more males than females end their life by suicide. Previous research indicates male-specific risk factors include social factors such as being unmarried, low income, and unemployment. An analytic model of male suicide is developed, proposing that the traditional male gender role creates a culturally-conditioned narrowing of perceived options and cognitive rigidity when under stress that increases male suicide risk. Suicide prevention and intervention require recognition of the role of high traditional masculinity, situating individual explanations within a broader social context. Based on this …

Thirdhand Tobacco Smoke: Emerging Evidence And Arguments For A Multidisciplinary Research Agenda, Georg E. Matt, Penelope J. Quintana, Hugo Destaillats, Lara A. Gundel, Mohamad Sleiman, Brett C. Singer, Peyton Jacob, Jonathan P. Winickoff, Prue Talbot, Suzaynn Schick, Yinsheng Wang, Bo Hang, Manuela Martins-Green, James F. Pankow, Melbourne F. Hovell, Neal L. Benowitz, Virender K. Rehan, Jonathan M. Samet

Civil and Environmental Engineering Faculty Publications and Presentations

There is broad consensus regarding the health impact of tobacco use and secondhand smoke exposure, yet considerable ambiguity exists about the nature and consequences of thirdhand smoke (THS). We introduce definitions of THS and THS exposure and review recent findings about constituents, indoor sorption-desorption dynamics, and transformations of THS; distribution and persistence of THS in residential settings; implications for pathways of exposure; potential clinical significance and health effects; and behavioral and policy issues that affect and are affected by THS. Physical and chemical transformations of tobacco smoke pollutants take place over time scales ranging from seconds to months and include …