Physical Sciences and Mathematics Commons^™

Naturalized Communication And Testing, Marly Roncken, Swetha Mettala Gilla, Hoon Park, Navaneeth Prasannakumar Jamadagni, Christopher Cowan, Ivan Sutherland

Computer Science Faculty Publications and Presentations

We ”naturalize” the handshake communication links of a self-timed system by assigning the capabilities of filling and draining a link and of storing its full or empty status to the link itself. This contrasts with assigning these capabilities to the joints, the modules connected by the links, as was previously done. Under naturalized communication, the differences between Micropipeline, GasP, Mousetrap, and Click circuits are seen only in the links — the joints become identical; past, present, and future link and joint designs become interchangeable. We also “naturalize” the actions of a self-timed system, giving actions status equal to states — …

Combining And Aggregating Environmental Data For Status And Trend Assessments: Challenges And Approaches, Kathleen G. Maas-Hebner, Michael Harte, Nancy Molina, Robert M. Hughes, Carl B. Schreck, J. Alan Yeakley

Environmental Science and Management Faculty Publications and Presentations

Increasingly, natural resource management agencies and nongovernmental organizations are sharing monitoring data across geographic and jurisdictional boundaries. Doing so improves their abilities to assess local-, regional-, and landscape-level environmental conditions, particularly status and trends, and to improve their ability to make short-and long-term management decisions. Status monitoring assesses the current condition of a population or environmental condition across an area. Monitoring for trends aims at monitoring changes in populations or environmental condition through time. We wrote this paper to inform agency and nongovernmental organization managers, analysts, and consultants regarding the kinds of environmental data that can be combined with suitable …

Micro-Policies: Formally Verified, Tag-Based Security Monitors, Arthur Azevedo De Amorim, Maxime Denes, Nick Giannarakis, Cătălin Hriţcu, Benjamin C. Pierce, Antal Spector-Zabusky, Andrew Tolmach

Computer Science Faculty Publications and Presentations

Recent advances in hardware design have demonstrated mechanisms allowing a wide range of low-level security policies (or micro-policies) to be expressed using rules on metadata tags. We propose a methodology for defining and reasoning about such tag-based reference monitors in terms of a high-level “symbolic machine,” and we use this methodology to define and formally verify micro-policies for dynamic sealing, compartmentalization, control-flow integrity, and memory safety; in addition, we show how to use the tagging mechanism to protect its own integrity. For each micro-policy, we prove by refinement that the symbolic machine instantiated with the policy’s rules embodies a high-level …

On The Temporal Evolution Of Long-Wavelength Mantle Structure Of The Earth Since The Early Paleozoic, Shijie Zhong, Maxwell L. Rudolph

Geology Faculty Publications and Presentations

The seismic structure of the Earth’s lower mantle is characterized by a dominantly degree-2 pattern with the African and Pacific large low shear velocity provinces (i.e., LLSVP) that are separated by circum-Pacific seismically fast anomalies. It is important to understand the origin of such a degree-2 mantle structure and its temporal evolution. In this study, we investigated the effects of plate motion history and mantle viscosity on the temporal evolution of the lower mantle structure since the early Paleozoic by formulating 3-D spherical shell models of thermochemical convection. For convection models with realistic mantle viscosity and no initial structure, it …

Estimating The Recreational Value Of Portland’S Forest Park, Randall Bluffstone, Ryan Burchett, Kahtan Eiwaz, Emma Ingebretsen, Peter Schaffer, Steve Toth, Szeto Yan Weng, Jordan Drinkhouse, Dat Huynh, Charles Maxwell, Joel Schutte, Tiffany Tram, Thananan Yupparit

Economics Faculty Publications and Presentations

Using the travel cost method, this study estimates the per-trip value and total annual value of recreational visits to Portland’s Forest Park. Based on the opportunity cost of visitors’ time and the estimated costs of travel, we derive a demand function for visits to Forest Park on the assumption that visitors value their trips to Forest Park at least as highly as the alternative uses of their time and money. The Portland Parks and Recreation Department supplied survey data for 2277 Forest Park visitors, of which we use 1626 observations.

We find that a truncated negative binomial regression best fits …

Flavour Chemicals In Electronic Cigarette Fluids, Peyton A. Tierney, Clarissa D. Karpinski, Jessica E. Brown, Wentai Luo, James F. Pankow

Chemistry Faculty Publications and Presentations

Background: Most e-cigarette liquids contain flavour chemicals. Flavour chemicals certified as safe for ingestion by the Flavor Extracts Manufacturers Association may not be safe for use in e-cigarettes. This study identified and measured flavour chemicals in 30 e-cigarette fluids.

Methods: Two brands of single-use e-cigarettes were selected and their fluids in multiple flavour types analysed by gas chromatography/mass spectrometry. For the same flavour types, and for selected confectionary flavours (eg, bubble gum and cotton candy), also analysed were convenience samples of e-cigarette fluids in refill bottles from local ‘vape’ shops and online retailers.

Results: In many liquids, total flavour chemicals …

Landforms Along The Lower Columbia River And The Influence Of Humans, Charles Matthew Cannon

Dissertations and Theses

River systems, such as the Columbia River in the Pacific Northwest, USA have been influenced by human activities, resulting in changes to the physical processes that drive landform evolution. This work describes an inventory of landforms along the Columbia River estuary between the Pacific Ocean and Bonneville Dam in Oregon and Washington. Groupings of landforms are assigned to formative process regimes that are used to assess historical changes to floodplain features. The estuary was historically a complex system of channels with a floodplain dominated by extensive tidal wetlands in the lower reaches and backswamp lakes and wetlands in upper reaches. …

Structure Of Local Quantum Operations And Classical Communication: Finite Versus Infinite Rounds, Scott M. Cohen

Physics Faculty Publications and Presentations

Every measurement that can be implemented by local quantum operations and classical communication (LOCC) using an infinite number of rounds is the limit of a sequence of measurements, where each measurement in the sequence requires only a finite number of rounds. This rather obvious and well-known fact is nonetheless of interest as it shows that these infinite-round measurements can be approximated arbitrarily closely simply by using more and more rounds of communication. Here we demonstrate the perhaps less obvious result that (at least) for bipartite systems, the reverse relationship also holds. Specifically, we show that every finite-round bipartite LOCC measurement …

Stochastic Comparisons Of Weighted Sums Of Arrangement Increasing Random Variables, Xiaoqing Pan, Min Yuan, Subhash C. Kochar

Mathematics and Statistics Faculty Publications and Presentations

Assuming that the joint density of random variables X1,X2, . . . ,Xn is arrangement increasing (AI), we obtain some stochastic comparison results on weighted sums of Xi’s under some additional conditions. An application to optimal capital allocation is also given.

Peripheral No More: Repositioning Narratives For Empowerment And Change In Sustainability Education, Rell G. Ohlson

Leadership for Sustainability Education Comprehensive Papers

The field of sustainability education challenges dominant modes of thought, with a particular emphasis on the need for diversity and "multiple perspectives" in order to confront complex issues (Capra, 2005; Sterling, 2001; Wheatley, 2006). If this is the case, why are certain perspectives still missing and what narratives have been given prominence? This comprehensive paper examines the problems of a dominant narrative in sustainability education. In order for sustainability education to be truly transformative and empowering for students, leaders, and their communities, the narrative of sustainability must be repositioned from a dominant, white, middle-class context to one that affirms, values …

Forest Park Ecosystems Services Inventory: An Exploratory Study, Pablo Barreyro, Jenny Dempsey Stein

Institute for Sustainable Solutions Publications and Presentations

This report presents both qualitative and quantitative survey data concerning resident perceptions of ecosystem services in Portland’s Forest Park. Focus group best practices and ecosystem services in urban parks literature are reviewed. Representative focus groups were conducted to ascertain local awareness and understanding of the urban wilderness area’s ecosystem services, identify concurrent challenges and measure interest in a potential interpretive center. Individual surveys were also administered in order to connect issues with demographics and recreational use information. Regression analyses were conducted to examine related park usage, access and economic trends.

While the study is preliminary, the results reveal opportunities for …

The Blue Heron Wetland Restoration Project: Eradication Of Ludwigia Peploides Ssp. Montevidensis From The Blue Heron Wetlands Of Portland, Or, Alexander Staunch

Environmental Science and Management Professional Master's Project Reports

The Blue Heron Wetland Restoration Project (BHWRP) is an ongoing community driven effort to eradicate Ludwigia peploides ssp. montevidensis from a 3.5 acre ephemeral wetland in Portland, OR. Established in summer 2011 by the East Columbia Neighborhood Association (ECNA), the BHWRP consisted of an herbicide efficacy pilot study, widespread eradication effort, and establishment of a stewardship program. Ludwigia peploides ssp. montevidensis is an emerging threat to northwestern Oregon and the infestation within the Blue Heron Wetlands (BHW) represented one of the first known infestations of L. peploides ssp. montevidensis within the State of Oregon.

First observed within the BHW in …

Climate Change And Land Management Impact Rangeland Condition And Sage-Grouse Habitat In Southeastern Oregon, Megan K. Creutzburg, Emilie B. Henderson, David R. Conklin

Environmental Science and Management Faculty Publications and Presentations

Contemporary pressures on sagebrush steppe from climate change, exotic species, wildfire, and land use change threaten rangeland species such as the greater sage-grouse (Centrocercus urophasianus). To effectively manage sagebrush steppe landscapes for long-term goals, managers need information about the potential impacts of climate change, disturbances, and management activities. We integrated information from a dynamic global vegetation model, a sage-grouse habitat climate envelope model, and a state-and-transition simulation model to project broad-scale vegetation dynamics and potential sage-grouse habitat across 23.5 million acres in southeastern Oregon. We evaluated four climate scenarios, including continuing current climate and three scenarios of global …

Aerosol Optical Hygroscopicity Measurements During The 2010 Cares Campaign, Dean B. Atkinson, James Gregory Radney, Janel Lum, Katheryn R. Kolesar, Daniel J. Cziczo, Mikhail Pekour, Qi Zhang, Ari Setyan, Alla Zelenyuk, Christopher D. Cappa

Chemistry Faculty Publications and Presentations

Measurements of the effect of water uptake on particulate light extinction or scattering made at two locations during the 2010 CARES study around Sacramento, CA are reported. The observed influence of water uptake, characterized through the dimensionless optical hygroscopicity parameter γ, is compared with calculations constrained by observed particle size distributions and size-dependent particle composition. A closure assessment has been carried out that allowed for determination of the average hygroscopic growth factors (GF) at 85% relative humidity and the dimensionless hygroscopicity parameter κ for oxygenated organic aerosol (OA) and for supermicron particles, yielding κ = 0.1–0.15 and 0.9–1.0, respectively. The …

Comparison Of Fish Assemblages In Restored And Natural Mangrove Habitats Along An Urban Shoreline, Joseph R. Peters, Lauren A. Yeager, Craig A. Layman

Environmental Science and Management Faculty Publications and Presentations

The installation of living shorelines is one strategy used to ameliorate habitat degradation along developed coastlines. In this process, existing hard structures, such as sea walls and riprap revetments, are supplemented with habitat forming species, e.g., oysters and mangrove trees, to improve habitat quality and function. Shoreline restorations in Biscayne Bay, Florida, USA, often utilize red mangroves, Rhizophora mangle (Linneaus, 1753), in addition to riprap revetments, to help stabilize the shoreline. This riprap-mangrove habitat provides structure for marine organisms to utilize and is believed to improve shoreline habitats in areas previously cleared of mangroves. We examined whether habitat provisioning was …

Factors Of Successful Collaboration: Oregon's Watershed Councils As Collaborative Systems, Meghan Doherty, National Policy Consensus Center

National Policy Consensus Center Publications and Reports

The public sector, business professionals and organization leaders are among some of the diverse entities increasingly viewing collaboration as a useful, and at times necessary, practice. Collaborative systems are networks formed by individuals who repeatedly interact over long time horizons to solve problems and achieve goals they could not on their own. Throughout the academic literature, there are many references to and definitions of collaborative systems or networks, as well as various opinions on what factors enable these systems to be successful. However, these are usually context-specific or limited to the perspective of a certain discipline. Furthermore, empirical literature usually …

Performance Metrics For Depth-Based Signal Separation Using Deep Vertical Line Arrays, John K. Boyle

Dissertations and Theses

Vertical line arrays (VLAs) deployed below the critical depth in the deep ocean can exploit reliable acoustic path (RAP) propagation, which provides low transmission loss (TL) for targets at moderate ranges, and increased TL for distant interferers. However, sound from nearby surface interferers also undergoes RAP propagation, and without horizontal aperture, a VLA cannot separate these interferers from submerged targets. A recent publication by McCargar and Zurk (2013) addressed this issue, presenting a transform-based method for passive, depth-based separation of signals received on deep VLAs based on the depth-dependent modulation caused by the interference between the direct and surface-reflected acoustic …

Development Of An Optical Method For The Detection Of Homocysteine As A Disease Biomarker Using Fluorescein-Aldehydes, Aabha Barve

Dissertations and Theses

Homocysteine is a natural occurring aminothiol. It is an intermediate product in the metabolism of methionine. Methionine is an essential amino acid required for protein synthesis. Metabolic irregularities disrupt homocysteine levels in plasma. Elevated homocysteine levels are directly linked to folate and cobalamin (vitamin B12) deficiencies, and are an independent risk factor for cardiovascular diseases. High homocysteine levels have also been associated with Alzheimer's, osteoporosis, renal failure, cancer, birth defects and pregnancy complications. The association of elevated homocysteine levels with cardiovascular disease and other diseases has generated great interest in the detection of homocysteine.

An optical method for the detection …

Spectroscopy, Nmr, And Electrochemistry Studies Of Protonated Aminophenyl/Pyridyl Porphyrins And Their Application In Hydrogen Evolution, Chenyi Wang

Dissertations and Theses

Spectrophotometric titrations for a full series of 4-aminophenyl/4-pyridyl meso-substituted porphyrins were carried out using methanesulfonic acid in DMSO to study the hyperporphyrin effect across different substitution patterns. The series included zero, one, two (cis and trans), three, and four meso(4-aminophenyl) groups, with the remaining meso substituents being 4-pyridyl groups. The peripheral pyridyl groups consistently protonate before the interior porphyrin pyrrole nitrogens, which protonate before the aminophenyl groups. Aminophenyl substituents increase the basicity of the pyrrole nitrogens and lead to distinctive hyperporphyrin spectra with a broad Soret band and a strong red absorption. The structure proposed to give rise to these …

Facile Methods For The Analysis Of Lysophosphatidic Acids In Human Plasma, Jialu Wang

Dissertations and Theses

Lysophosphatidic acid (LPA) influences many physiological processes, such as brain and vascular development. It is associated with several diseases including ovarian cancer, breast cancer, prostate cancer, colorectal cancer, hepatocellular carcinoma, multiple myeloma atherosclerotic diseases, cardiovascular diseases, pulmonary inflammatory diseases and renal diseases. LPA plasma and serum levels have been reported to be important values in diagnosing ovarian cancer and other diseases. However, the extraction and quantification of LPA in plasma are very challenging because of the low physiological concentration and similar structures of LPA to other phospholipids. Many previous studies have not described the separation of LPA from other phospholipids, …

Prussian Green: A High Rate Capacity Cathode For Potassium Ion Batteries, Prasanna Pradigi, Joseph Thiebes, Mitchell Swan, Gary Goncher, David Evans, Raj Solanki

Physics Faculty Publications and Presentations

The influence of the precursors, namely potassium ferrocyanide and potassium ferricyanide on the particles sizes of Prussian Blue (PB) and Prussian Green (PG), under identical reaction conditions have been investigated. It was found that the particle sizes influence the gravimetric capacity utilization of these materials as cathodes for aqueous potassium (K⁺ ) ion batteries. The PG particle sizes were on the order of 50-75 nm, whereas PB particles size were on the order of 2-10 microns. The PG cathodes demonstrated a reversible capacity of 121.4 mAhr/g, with a coulombic efficiency of 98.7% compared to PB cathodes which demonstrated 53.8 …

A Novel Approach To Flow And Sediment Transport Estimation In Estuaries And Bays, Hamed Moftakhari Rostamkhani

Dissertations and Theses

Reliable estimates of river discharge and sediment transport to the ocean from large tidal rivers are vital for water resources management, efficient river and harbor management, navigational purposes, and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, hydrological and sedimentological records are typically too short to adequately characterize long-term (decadal) trends. Also, uncertainties associated with observation and calibration of hydrological models suggest a need for more accurate methods based on longer records of hydrodynamic parameters (e.g. tides). Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave …

Intersections Of Critical Systems Thinking And Community Based Participatory Research In Developing A Web Site For Autistic Adults, Dora Madeline Raymaker

Dissertations and Theses

People with disabilities, including those on the autism spectrum, comprise the world's largest minority and experience significant inequities in Internet use. Existing standards for accessible web sites are necessary but not sufficient without the direct engagement of end users in identifying access needs. Yet little is known about methods for effective engagement, and there are no systematically derived Web accessibility guidelines for autistic end users. Here I explore a hybrid approach to direct engagement using critical systems thinking (CST) and community based participatory research (CBPR) during the co-development of a healthcare-focused web site by the Academic Autism Spectrum Partnership in …

Aberration Corrected Photoemission Electron Microscopy With Photonics Applications, Joseph P. S. Fitzgerald

Dissertations and Theses

Photoemission electron microscopy (PEEM) uses photoelectrons excited from material surfaces by incident photons to probe the interaction of light with surfaces with nanometer-scale resolution. The point resolution of PEEM images is strongly limited by spherical and chromatic aberration. Image aberrations primarily originate from the acceleration of photoelectrons and imaging with the objective lens and vary strongly in magnitude with specimen emission characteristics. Spherical and chromatic aberration can be corrected with an electrostatic mirror, and here I develop a triode mirror with hyperbolic geometry that has two adjacent, field-adjustable regions. I present analytic and numerical models of the mirror and show …

Modifications To A Cavity Ringdown Spectrometer To Improve Data Acquisition Rates, Gregory Alan Bostrom

Dissertations and Theses

Cavity ringdown spectroscopy (CRDS) makes use of light retention in an optical cavity to enhance the sensitivity to absorption or extinction of light from a sample inside the cavity. When light entering the cavity is stopped, the output is an exponential decay with a decay constant that can be used to determine the quantity of the analyte if the extinction or absorption coefficient is known. The precision of the CRDS is dependent on the rate at which the system it acquires and processes ringdowns, assuming randomly distributed errors. We have demonstrated a CRDS system with a ringdown acquisition rate of …

Leveraging Contextual Relationships Between Objects For Localization, Clinton Leif Olson

Dissertations and Theses

Object localization is currently an active area of research in computer vision. The object localization task is to identify all locations of an object class within an image by drawing a bounding box around objects that are instances of that class. Object locations are typically found by computing a classification score over a small window at multiple locations in the image, based on some chosen criteria, and choosing the highest scoring windows as the object bounding-boxes. Localization methods vary widely, but there is a growing trend towards methods that are able to make localization more accurate and efficient through the …

Zebra And Quagga Mussel Early-Detection Monitoring In High Risk Oregon Waters 2014, Steve W. Wells, Mark D. Sytsma

Center for Lakes and Reservoirs Publications and Presentations

Zebra and quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively) were not detected by Oregon Department of Fish and Wildlife (ODFW) and Portland State University (PSU) during their early detection sampling in Oregon water bodies during 2014. Six high-risk Oregon water bodies were sampled for planktonic larvae and adult mussels during the August to September period. A total of 37 plankton samples were collected and over 520,000 liters of reservoir/lake water were filtered through 64-μm mesh nets during plankton sample collection. The greatest sampling effort occurred in Emigrant Lake, Lake Billy Chinook, and Prineville Reservoir but sampling also occurred …

Oregon Lake Watch, 2014 Annual Report, Meredith Jordan, Rich Miller, Angela L. Strecker

Center for Lakes and Reservoirs Publications and Presentations

The Oregon Lake Watch (OLW) volunteer monitoring program is now in its second year of operation, continuing its focus on early detection of aquatic invasive species (AIS), with a secondary focus on lake water quality. The aquatic invasive species chosen as Watch List priorities for the OLW are based on the Oregon Department of Agriculture’s Noxious Weed List (Oregon Department of Agriculture Noxious Weed Control Program 2014) as well as professional judgement (more information can be found in Oregon Lake Watch Final Report 2014). This report summarizes the data collected by 15 of 24 OLW volunteers over 2014, across 110 …

Who Is At The Forest Restoration Table? Final Report On The Blue Mountains Forest Stewardship Network, Phase 1, Rebecca J. Mclain, Kirsten Wright, Lee Cerveny

Institute for Sustainable Solutions Publications and Presentations

Forest collaboratives have emerged throughout the western U.S. as a governance model to address complex ecological challenges that occur at the landscape scale across multiple landownerships and jurisdictional boundaries. Collaborative groups typically involve multiple parties with diverse interests working together to address complex management challenges. Collaboratives often provide input on or make recommendations about public lands actions and decisions. The Blues Stewardship Project was developed to better understand the size, composition, participation, and diversity of forest collaboratives and to identify organizations that may not currently be represented at the collaborative ‘table.’

The study focuses on five collaborative groups in the …

Comparison Between Observed And Model-Simulated Atmospheric Circulationpatterns Associated With Extreme Temperature Days Over North Americausing Cmip5 Historical Simulations, Paul C. Loikith, Anthony J. Broccoli

Geography Faculty Publications and Presentations

Circulation patterns associated with extreme temperature days over North America, as simulated by a suite of climate models, are compared with those obtained from observations. The authors analyze 17 coupled atmosphere–ocean general circulation models contributing to the fifth phase of the Coupled Model Intercomparison Project. Circulation patterns are defined as composites of anomalies in sea level pressure and 500-hPa geopotential height concurrent with days in the tails of temperature distribution. Several metrics used to systematically describe circulation patterns associated with extreme temperature days are applied to both the observed and model-simulated data. Additionally, self-organizing maps are employed as a means …