Physical Sciences and Mathematics Commons^™

A Tent Pitching Scheme Motivated By Friedrichs Theory, Jay Gopalakrishnan, Peter Monk, Paulina Sepulveda

Mathematics and Statistics Faculty Publications and Presentations

Certain Friedrichs systems can be posed on Hilbert spaces normed with a graph norm. Functions in such spaces arising from advective problems are found to have traces with a weak continuity property at points where the inflow and outflow boundaries meet. Motivated by this continuity property, an explicit space-time finite element scheme of the tent pitching type, with spaces that conform to the continuity property, is designed. Numerical results for a model one-dimensional wave propagation problem are presented.

Defining The Terroir Of The Columbia Gorge Wine Region, Oregon And Washington, Usa Using Geographic Information Systems (Gis), Hilary Whitney

Dissertations and Theses

The Columbia Gorge Wine Region (CGWR) is an emerging wine producing area that extends for about 100km along the Columbia River in Oregon and Washington State in which the number of vineyards, wineries and physical terroir conditions have yet to be defined. To better understand the physical factors affecting Oregon and Washington wine, this project analyzes climate, topography, geology and soil at vineyards in the CGWR. This was accomplished using Geographic Information Systems, existing earth science databases and field work. The region, which includes the Columbia Gorge American Viticulture Area (AVA) and the southwest portion of the Columbia Valley AVA, …

On Stochastic Comparisons Of Largest Order Statistics In The Scale Model, Subhash C. Kochar, Nuria Torrado

Mathematics and Statistics Faculty Publications and Presentations

Let X-lambda 1, X-lambda 2, ... ,X-lambda n be independent non negative random variables with X-lambda i similar to F(lambda(i)t), i = 1, ... , n, where lambda(i) > 0, i = 1, ... , n and F is an absolutely continuous distribution. It is shown that, under some conditions, one largest order statistic X-n:n(lambda) n is smaller than another one X-n:n(theta) according to likelihood ratio ordering. Furthermore, we apply these results when F is a generalized gamma distribution which includes Weibull, gamma and exponential random variables as special cases.

Improved Gain Stability Of A Digital Imager Using A Charge Feedback Amplifier, Elliot Eckman Mylott

Dissertations and Theses

Digital imagers including Charge-Coupled Devices (CCD) are essential to most forms of modern photographic technologies. The quality of the data produced by digital imagers have made them an invaluable scientific measurement tool. Despite the numerous advantages of digital imagers, there are still factors that limit their performance. One such factor is the stability of the camera's gain, the ratio that dictates the imager's ability to convert incident photons to a measurable output voltage. Variations in gain can affect the linearity of the device and produce inaccurate measurements.

One of the factors that determines the gain of the camera is the …

Exploratory Data Modeling Of Traumatic Brain Injury, Martin Zwick

Systems Science Faculty Publications and Presentations

A short presentation of an analysis of data from Dr. Megan Preece on traumatic brain injury, the first in a series of planned secondary analyses of multiple TBI data sets. The analysis employs the systems methodology of reconstructability analysis (RA), utilizing both variable- and state-based and both neutral and directed models. The presentation explains RA and illustrates the results it can obtain. Unlike the confirmatory approach standard to most data analyses, this methodology is designed for exploratory modeling. It thus allows the discovery of unanticipated associations among variables, including multi-variable interaction effects of unknown form. It offers the opportunity for …

Localized Ecological And Educational Effects Of Environmental Service-Learning In Portland, Oregon, Steven Matthew Braun

Dissertations and Theses

Environmental service-learning is an intentional educational experience(s) wherein learners engage in meaningful activities designed to serve the environment. Environmental service-learning activities vary according to their learning and service goals and include ecomanagement, persuasion, legal action, economic action and political action. The purpose of this mixed methods research was to explore the ecological and educational impacts of grades 6-12 environmental education, with special attention to environmental service-learning throughout Portland, Oregon.

Ecological impacts considered restoration and conservation outcomes of several environmental service-learning programs including plant communities, soils, litter removal and trail maintenance. Educational outcomes considered aspects of environmental literacy including locus of …

Investigations Of The Air-Water Interface: A Structural Analysis Of Metallic Surface Films And Aquatic Surface Films By Comparative Microscopy, Randall William Smith

Dissertations and Theses

The air-water interface is an important natural boundary layer that has been neglected as an area of environmental field research. This study establishes that comparative microscopy can be an effective environmental method, and establishes that the term metallic surface films, is a more accurate descriptor than iron oxide surface films. This research shows that surface films are complex, often with layered structure, serve as habitat for significant biota, and act as a point of mineralization to several transition metal elements including manganese, iron, copper, nickel and zinc. This study demonstrates that surface films form under several conditions and can have …

Post-Silicon Functional Validation With Virtual Prototypes, Kai Cong

Dissertations and Theses

Post-silicon validation has become a critical stage in the system-on-chip (SoC) development cycle, driven by increasing design complexity, higher level of integration and decreasing time-to-market. According to recent reports, post-silicon validation effort comprises more than 50% of the overall development effort of an 65nm SoC. Though post-silicon validation covers many aspects ranging from electronic properties of hardware to performance and power consumption of whole systems, a central task remains validating functional correctness of both hardware and its integration with software. There are several key challenges to achieving accelerated and low-cost post-silicon functional validation. First, there is only limited silicon observability …

Hardware/Software Interface Assurance With Conformance Checking, Li Lei

Dissertations and Theses

Hardware/Software (HW/SW) interfaces are pervasive in modern computer systems. Most of HW/SW interfaces are implemented by devices and their device drivers. Unfortunately, HW/SW interfaces are unreliable and insecure due to their intrinsic complexity and error-prone nature. Moreover, assuring HW/SW interface reliability and security is challenging. First, at the post-silicon validation stage, HW/SW integration validation is largely an ad-hoc and time-consuming process. Second, at the system deployment stage, transient hardware failures and malicious attacks make HW/SW interfaces vulnerable even after intensive testing and validation. In this dissertation, we present a comprehensive solution for HW/SW interface assurance over the system life cycle. …

Novel Methods For Learning And Adaptation In Chemical Reaction Networks, Peter Banda

Dissertations and Theses

State-of-the-art biochemical systems for medical applications and chemical computing are application-specific and cannot be re-programmed or trained once fabricated. The implementation of adaptive biochemical systems that would offer flexibility through programmability and autonomous adaptation faces major challenges because of the large number of required chemical species as well as the timing-sensitive feedback loops required for learning. Currently, biochemistry lacks a systems vision on how the user-level programming interface and abstraction with a subsequent translation to chemistry should look like. By developing adaptation in chemistry, we could replace multiple hard-wired systems with a single programmable template that can be (re)trained to …

An Investigation Of The Role Of Alternate Numeration Systems In Preservice Teacher Mathematics Content Courses, Jodi I. Fasteen

Dissertations and Theses

Alternate numeration systems are common in preservice teacher (PST) mathematics curricula, but there is limited research on how to leverage alternate systems to promote the development of mathematical knowledge for teaching. I analyzed the role of alternate numeration systems in three ways. I conducted a thematic analysis of current PST textbooks to consider the role of alternate numeration systems in written curricula. I conducted a teaching experiment to analyze PSTs' mathematical activity as they engaged with a base five task sequence to reinvent an algorithm for multiplication. And I introduced problematizing mathematical contexts as a design heuristic, situating this within …

Oregon Invasive Species Council Review, Robyn Draheim, Rob Fiegener, Lisa Gaines

Center for Lakes and Reservoirs Publications and Presentations

The Oregon Invasive Species Council (OISC – “Council” is also used in this report) was established by the Oregon Legislature in 2001 [ORS 570.750, formerly 561.687]. In partnership with a broad group of state, federal and local agencies, non-profit organizations, industry representatives and individuals, the Council created and maintains the means for citizens to report sightings of invasive species and a process by which this information is forwarded to appropriate agencies; works to increase citizen engagement and awareness of invasive issues; conducts educational meetings and conferences; and, administers a trust account for funding eradication and educational projects.

In 2014, the …

Herbicide Resistance: Challenges For Farmers And Implications For The Environment, George Frisvold, David E. Ervin

Economics Faculty Publications and Presentations

Genetically modified, herbicide resistant (HR) crops offer not only improved weed control, but also the potential to reduce soil erosion and fossil fuel use and to allow substitution toward less toxic or persistent herbicides. The widespread adoption of HR crops, however, has reduced the diversity of weed control tactics and increased ecological selection pressure for weeds resistant to dominant herbicides. This has led to a dramatic rise of HR weeds in many cropping systems. Resistant weeds threaten the sustainability of HR crops, pose environmental risks from alternative weed control practices, are altering public and private R&D programs, and necessitate new …

Experiential Knowledge And Interdisciplinary Approaches To Address Herbicide Resistance: Insights From Theory And Practice, David Shaw, David E. Ervin

Economics Faculty Publications and Presentations

The exponential increase in herbicide resistant weeds around the globe poses a “wicked problem” that resists solutions developed from disciplinary science (Ervin and Jussaume; Shaw). Traditonal voluntary education and technical assistance approaches have failed to stem the advance of resistance. Scholars and practitioners recognize that improved understanding of human behavior leading to more resistant weeds must provide the foundation of knowledge for innovating more effective approaches. Principles to negotiate progress on wicked problems stress interdisciplinary approaches that integrate frontier social and natural science concepts with stakeholder experiences to discover novel approaches (Sayer et al). Standard templates to address the problem …

Dynamics Of Locally Coupled Oscillators With Next-Nearest-Neighbor Interaction, J. Herbrych, A. G. Chazirakis, N. Christakis, J. J. P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

A theoretical description of decentralized dynamics within linearly coupled, one-dimensional oscillators (agents) with up to next-nearest-neighbor interaction is given. Conditions for stability of such system are presented. Our results indicate that the stable systems have response that grow at least linearly in the system size. We give criteria when this is the case. The dynamics of these systems can be described with traveling waves with strong damping in the high frequencies. Depending on the system parameters, two types of solutions have been found: damped oscillations and reflectionless waves. The latter is a novel result and a feature of systems with …

Type And Timing Of Stream Flow Changes In Urbanizing Watersheds In The Eastern U.S., Kristina G. Hopkins, Nathaniel B. Morse, Daniel J. Bain, Neil D. Bettez, Nancy B. Grimm, Jennifer L. Morse, Monica M. Palta

Environmental Science and Management Faculty Publications and Presentations

Linking the type and timing of hydrologic changes with patterns of urban growth is essential to identifying the underlying mechanisms that drive declines in urban aquatic ecosystems. In six urbanizing watersheds surrounding three U.S. cities (Baltimore, MD, Boston, MA, and Pittsburgh, PA), we reconstructed the history of development patterns since 1900 and assessed the magnitude and timing of stream flow changes during watershed development. Development reconstructions indicated that the majority of watershed development occurred during a period of peak population growth, typically between 1950 and 1970. Stream flow records indicated significant increases in annual frequency of high-flow events in all …

Climate Change Assessment In Columbia River Basin (Crb) Using Copula Based On Coupling Of Temperature And Precipitation, Yueyue Qin

Dissertations and Theses

The multi downscaled-scenario products allow us to better assess the uncertainty of the variations of precipitation and temperature in the current and future periods. Joint Probability distribution functions (PDFs), of both the climatic variables, might help better understand the interdependence of the two, and thus in-turn help in accessing the future with confidence. In the present study, we have used multi-modelled statistically downscaled ensemble of precipitation and temperature variables. The dataset used is multi-model ensemble of 10 Global Climate Models (GCMs) downscaled product from CMIP5 daily dataset, using the Bias Correction and Spatial Downscaling (BCSD) technique, generated at Portland State …

The Erosion Of Coastal Sediment And Regeneration Of Rhizophora Mangle Following Anthropogenic Disturbance On Turneffe Atoll, Belize, Heather Lyn Hayden

Dissertations and Theses

As communities and managers become aware of the long-term impacts of mangrove loss, estimated at 1-2% per year, interest in sediment erosion and mangrove rehabilitation has increased substantially. In this thesis project I 1) examine erosion rates within coastal fringing Rhizophora mangle ecosystems following mangrove clearing and compare these rates to accretion rates in intact mangroves; and 2) investigate the abiotic factors influencing mangrove seedling survival and regeneration of naturally colonizing R. mangle, in historic mangrove habitat after anthropogenic clearing.

Differences in erosion were compared between patches of open-coast intact and anthropogenically cleared R. mangle to quantify the sediment trapping …

The Response Of Zooplankton Communities In Montane Lakes Of Different Fish Stocking Histories To Atmospheric Nitrogen Deposition Simulations, Jeffrey Thomas Brittain

Dissertations and Theses

Freshwater ecosystems are subject to a wide variety of stressors, which can have complex interactions and result in ecological surprises. Non-native fish introductions have drastically reduced the number of naturally fishless lakes and have resulted in cascading food web repercussions in aquatic and terrestrial habitats. Additional anthropogenic influences that result from increases in global airborne emissions also threaten wildlife habitat. Atmospheric nitrogen deposition has been recognized as an anthropogenic contributor to acidification and eutrophication of wilderness ecosystems. Planktonic communities have shown declines in response to predation and shifts in composition as a result of nutrient inputs and acidification, both of …

Effects Of Selective Logging And Roads On Instream Fine Sediments And Macroinvertebrate Assemblages In The Clackamas Basin, Oregon, Paula Elizabeth Hood

Dissertations and Theses

Logging and associated skid trails, haul routes, and roads can have significant impacts on the magnitude and timing of sediments in streams in forested watersheds. Loss of vegetation, soil compaction, use of heavy logging equipment, and alteration of natural hydrologic patterns within the watershed can increase landslide rates, create erosion, and generate fine sediments. Selective logging, also called thinning, is a logging practice that leaves some trees within sale units unharvested. The ecological impacts of thinning on stream ecosystems are not fully understood and need further study. My hypothesis was that macroinvertebrate assemblages would be different in streams in non-reference …

Academic Incoherence: The State Of Sustainability Literature Today, Anthony Philip Stine

Student Research Symposium

The traditional tools associated with researching and presenting findings in contemporary sustainability literature include very little representation on moral forms of discourse. In the context of social sustainability this is problematic due to the inherently normative nature of the discourse. A citation analysis reveals very little representation of Christian moral environmental claims in the sustainability literature today despite growing concern amongst Christians for the state of the environment today.

Nwa 8614: The Least Heated Winonaite, Karla Farley, Alexander M. Ruzicka, Katherine Armstrong

Student Research Symposium

Northwest Africa 8614 is classified as a winonaite on the basis of oxygen isotope ratios, mineralogy, and highly reduced chemistry. Unlike other winonaites, it contains numerous and readily apparent chondrules. Here we discuss various features of NWA 8614 and the possible significance of the meteorite.

Petrological and chemical analyses were performed using optical microscopy with a DM2500 Leica petrographic microscope and a Zeiss Sigma VP-FEG scanning electron microscope (SEM) with a high-efficiency energy dispersive spectrometer (EDS). Oxygen isotopes were analyzed by Karen Ziegler at the University of New Mexico on acid-washed samples to remove terrestrial weathering products.

Owing to the …

Design, Construction, And Utilization Of Physical Vapor Deposition Systems For Medical Sensor Fabrication, Nicholas Sayre, Abdul Almetairi, Alex Chally, Joe Kowalski, Erik J. Sánchez

Student Research Symposium

The development of a novel blood glucose sensor is realized through construction of a homemade plasma coating system and utilization of semiconductor manufacturing processes in a small scale cleanroom environment. Photolithography, plasma sputtering, chemical etching and thin film measurement technologies are used in the medical sensor fabrication process. General process flow will be discussed, and system design and the plasma sputtering process will be presented as it is achieved by the system currently under development.

The Smallest Intersecting Ball Problem, Daniel J. Giles, Mau Nam Nguyen

Student Research Symposium

The smallest intersecting ball problem involves finding the minimal radius necessary to intersect a collection of closed convex sets. This poster discusses relevant tools of convex optimization and explores three methods of finding the optimal solution: the subgradient method, log-exponential smoothing, and an original approach using target set expansion. A fourth algorithm based on weighted projections is given, but its convergence is yet unproven. Numerical tests and comparison between methods are also presented.

Non-Orientable Objects As Gaming Surfaces, Haley P. Bourke, Paul Latiolais

Student Research Symposium

Developed in Python, Klein Space Fighter is an interactive learning tool and mathematically themed arcade game that allows the player to combat on different mathematical surfaces including a 2D Klein bottle. The app is available for Android and desktop devices, and will be made available for iOS in the future.

To receive an invitation to download the app through Google Play, contact me at HaleyoBourke@yahoo.com

Structure From Motion Elevation Model For Adding Topographic Correction To Ground Penetrating Radar, Leslie A. Mowbray

Student Research Symposium

High resolution elevation models have become a standard tool in environmental, geological and archaeological investigations, however; the cost of acquiring Lidar in remote areas, on small project sites or over repeated time intervals remains prohibitively expensive. Here, open-source software and GIS are used to create a digital elevation model (DEM) from aerial photos in a process known as Structure from Motion (SfM). This process is a fraction of the cost of Lidar acquisition, and is shown to produce a model with comparable resolution. The photos used here were taken from a camera hung from a balloon flown at Mickey Springs …

Urban Scale Modeling Of Atmospheric Carbon Dioxide And Validation Of Emission Inventories, James E. Powell, Christopher L. Butenhoff, Andrew L. Rice

Student Research Symposium

There exists a pressing need for high resolution emissions inventories for cities. For greenhouse gases, cities and regions need a careful analysis of their carbon footprint to design effective policies to control and mitigate emissions. High resolution emissions inventories can be used in conjunction with meteorology models and atmospheric measurements to place top-down constraints on emissions. High resolution emissions inventories for criteria pollutants like NO_x, CO, and O₃ enable urban-scale air pollution modeling down to the neighborhood level. For example, the Vulcan project estimates CO₂ using county-scale vehicle miles traveled (VMT) from the National Mobile Inventory …

Bicrystallography In Two Dimensions: A Graphical Procedure And Comparison Of Its Results To Experiments, Andrew M. Maas, Peter Moeck

Student Research Symposium

Three dimensional (3D) bicrystallography describes ideal structures of grain boundaries comprehensively at the atomic level as a function of the five macroscopic and two of the four microscopic parameters [1,2]. Free energy minimization of these structures leads to the real structure of these topologically distinct regions within crystals. These minimizations may either reduce the symmetries of ideal bicrystals or leave them intact. Since the symmetries of physical properties need to be compatible (by the Shubnikov-Curie and Curie-Minnigerode-Neumann principles [3]) with the symmetries of the atomic arrangements from which they arise, bicrystallography allows for predictions about which phenomena can occur in …

Developing Key Sustainability Competencies Through Real-World Learning Experiences: Evaluating Community Environmental Services, Erin Lorene Anderson

Dissertations and Theses

This study focuses on sustainability in higher education and the competencies essential to address sustainability issues. Because sustainability issues are complex, "wicked", and dynamic, sustainability education programs need to reflect the interdisciplinary and collaborative nature of the field. Graduates who are competent in sustainability research and problem solving will have the knowledge, skills, and attitude necessary to analyze a sustainability problem systemically and comprehensively, then will construct and implement interventions to reach optimal sustainability solutions. To prepare graduates, sustainability education programs should facilitate the development of key sustainability competencies (Wiek, Withycombe, & Redman, 2011). Such programs provide an interdisciplinary approach …

Modeling The Optical Response To A Near-Field Probe Tip From A Generalized Multilayer Thin Film, A.J. Lawrence

Dissertations and Theses

The contrast mechanism in Kerr imaging is the apparent angle through which the plane of polarization is rotated upon reflection from a magnetic surface. This can be calculated for a well characterized surface given the polarization state of the incident light. As in traditional optical microscopy, the spatial resolution is limited by diffraction to roughly half the wavelength of the illumination light.

The diffraction limit can be circumvented through the use of near-field scanning optical microscopy, in which the illumination source is an evanescent field at the tip of a tapered optical fiber. A novel probe design for near-field optical …