Digital Commons Network^™

Integrating Landsat Tm/Etm+ And Numerical Modeling To Estimatewater Temperature In The Tigris River Under Future Climate And Management Scenarios, Muhanned Al-Murib, Scott Wells, Stefan Talke

Civil and Environmental Engineering Faculty Publications and Presentations

Modeling the water quality of rivers and assessing the effects of changing conditions is often hindered by a lack of in situ measurements for calibration. Here, we use a combination of satellite measurements, statistical models, and numerical modeling with CE-QUAL-W2 to overcome in situ data limitations and evaluate the effect of changing hydrologic and climate conditions on water temperature (T_w) in the Tigris River, one of the largest rivers in the Middle East. Because few in situ estimates of Tw were available, remotely-sensed estimates of Tw were obtained from Landsat satellite images at roughly 2 week intervals for …

Contrasting Local And Long-Range-Transported Warm Ice-Nucleating Particles During An Atmospheric River In Coastal California, Usa, Andrew C. Martin, Gavin Cornwell, Charlotte M. Beall, Forest Cannon, Sean Reilly, Bas Schapp, Dolan Lucero, Jessie Creamean, F. Martin Ralph, Hari T. Mix, Kimberly Prather

Geography Faculty Publications and Presentations

Ice-nucleating particles (INPs) have been found to influence the amount, phase and efficiency of precipitation from winter storms, including atmospheric rivers. Warm INPs, those that initiate freezing at temperatures warmer than −10ºC, are thought to be particularly impactful because they can create primary ice in mixed-phase clouds, enhancing precipitation efficiency. The dominant sources of warm INPs during atmospheric rivers, the role of meteorology in modulating transport and injection of warm INPs into atmospheric river clouds, and the impact of warm INPs on mixed-phase cloud properties are not well-understood. In this case study, time-resolved precipitation samples were collected during an atmospheric …

A Study Of Thermal Energy Storage Of Phase Change Materials: Thermophysical Properties And Numerical Simulations, Kyung-Eun Min

Dissertations and Theses

A Thermal Energy Storage (TES) system is meant for holding thermal energy in the form of hot or cold materials for later utilization. A TES system is an important technological system in providing energy savings as well as efficient and optimum energy use. The main types of a TES system are sensible heat and latent heat. A latent heat storage is a very efficient method for storing or releasing thermal energy due to its high energy storage density at constant temperatures, and a latent heat storage material can store 5-14 times more heat per unit volume than a sensible heat …

Addressing The Needs Of Non-Traditional Online Students In A Credit-Bearing Il Course, Sarah Ralston

Online Northwest

LIB 307: Online Research Tools and Strategies is a two-credit upper division information literacy course serving an online-only student population at Eastern Oregon University (EOU). The course examines search strategies and techniques used in general and discipline-specific research tools such as databases, library discovery systems, and free online content. EOU's online student population is made up of primarily non-traditional transfer students, most of whom have been out of school for many years, and have cobbled together credits from multiple colleges and universities. Many readily admit they have not used the library since it had a card catalog, and they may …

Localizing Little Landmarks With Transfer Learning, Sharad Kumar

Dissertations and Theses

Locating a small object in an image -- like a mouse on a computer desk or the door handle of a car -- is an important computer vision problem to solve because in many real life situations a small object may be the first thing that gets operated upon in the image scene. While a significant amount of artificial intelligence and machine learning research has focused on localizing prominent objects in an image, the area of small object detection has remained less explored. In my research I explore the possibility of using context information to localize small objects in an …

Capillary Migration Of Large Confined Drops In Non-Wetting Wedges, Logan John Torres

Dissertations and Theses

When confined within containers or conduits, drops and bubbles migrate to regions of minimum energy by the combined effects of surface tension, surface wetting, system geometry, and initial conditions. Such capillary phenomena are exploited for passive phase separation operations in micro-fluidic devices on earth and macro-fluidic devices aboard spacecraft. Our study focuses on the migration and ejection of large inertial-capillary drops confined between tilted planar hydrophobic substrates. In our experiments, the brief nearly weightless environment of a drop tower allows for the study of such capillary dominated behavior for up to 10 mL water drops with migration velocities up to …

The Quest For Model Uncertainty Quantification: A Hybrid Ensemble And Variational Data Assimilation Framework, Peyman Abbaszadeh, Hamid Moradkhani, Dacian Daescu

Civil and Environmental Engineering Faculty Publications and Presentations

This article presents a novel approach to couple a deterministic four‐dimensional variational (4DVAR) assimilation method with the particle filter (PF) ensemble data assimilation system, to produce a robust approach for dual‐state‐parameter estimation. In our proposed method, the Hybrid Ensemble and Variational Data Assimilation framework for Environmental systems (HEAVEN), we characterize the model structural uncertainty in addition to model parameter and input uncertainties. The sequential PF is formulated within the 4DVAR system to design a computationally efficient feedback mechanism throughout the assimilation period. In this framework, the 4DVAR optimization produces the maximum a posteriori estimate of state variables at the beginning …

Localized Photoemission In Triangular Gold Antennas, Christopher M. Scheffler

Dissertations and Theses

With the development of ultra-fast laser technology, several new imaging techniques have pushed optical resolution past the diffraction limit for traditional light-based optics. Advancements in lithography have enabled the straightforward creation of micron- and nanometer-sized optical devices. Exposing metal-dielectric structures to light can result in surface plasmon excitation and propagation along the transition interface, creating a surface plasmon polariton (SPP) response. Varying the materials or geometry of the structures, the plasmonic response can be tailored for a wide range of applications.

Photoemission electron microscopy (PEEM) has been used to image excitations in micron-sized plasmonic devices. With PEEM, optical responses can …

Stratospheric Polar Vortex Variability In The Northern Hemisphere: The Effects Of Climate Change On Polar Vortex Trends And Future Projections, John Earl Rogers

Dissertations and Theses

Regions that have experienced recent successive cold winters such as the Northeast of North America and Siberia have endured critical social and economic impacts from anomalous low temperatures in recent years, despite warming global temperatures. It is well known that the Tropospheric Polar Vortex (TPV), or jet stream, is a primary influence on many mid-latitude winter weather patterns. However, the strong circumpolar westerlies that maximize at around 60° latitude just above the tropopause, known as the Stratospheric Polar Vortex (SPV), can affect tropospheric circulation and thus winter weather in the Northern Hemisphere. Strong upward propagating waves can affect the geographic …

The Impact Of Infrastructure On Habitat Connectivity For Wildlife, Leslie Lynne Bliss-Ketchum

Dissertations and Theses

While roads can present weak to complete barriers to wildlife, depending on the animal and traffic volume, mitigations such as under-crossings and green bridges on highways at least partially increase the permeability of the landscape to some of these species. The few studies evaluating the effectiveness of these structures for at least three years typically focused on a single species. Here, we monitored the crossing structure under Boeckman Road, in Wilsonville Oregon, for wildlife activity across summer seasons for ten years, since construction of the road and subsequent opening to traffic. This long-term multi-species dataset, which includes monitoring when the …

Fractal Dimension As Objective Function In A Genetic Algorithm For Application In Architectural Design, John Charles Driscoll

Systems Science Friday Noon Seminar Series

One of the goals of The Green New Deal Resolution reads, “upgrading all existing buildings in the United States and building new buildings to achieve maximal energy efficiency, water efficiency, safety, affordability, comfort, and durability, including through electrification.”

How can this realistically be done given the sheer number of buildings in the United States? This presents a ‘wicked’ problem that calls out for a systems approach. This is also, in essence, a design problem. As data scientists we are used to using models to analyze data but there is another aspect to these models that can be used not to …

Efficient Methods For Robust Circuit Design And Performance Optimization For Carbon Nanotube Field Effect Transistors, Muhammad Ali

Dissertations and Theses

Carbon nanotube field-effect transistors (CNFETs) are considered to be promising candidate beyond the conventional CMOSFET due to their higher current drive capability, ballistic transport, lesser power delay product and higher thermal stability. CNFETs show great potential to build digital systems on advanced technology nodes with big benefits in terms of power, performance and area (PPA). Hence, there is a great need to develop proven models and CAD tools for performance evaluation of CNFET-based circuits. CNFETs specific parameters, such as number of tubes, pitch (spacing between the tubes) and diameter of CNTs determine current driving capability, speed, power consumption and area …

Jet Rebound From Hydrophobic Substrates In Microgravity, Karl Jeffrey Theodore Cardin

Dissertations and Theses

We experimentally investigate the phenomena of large jet rebound, a mode of fluid transfer following oblique jet impacts on hydrophobic substrates. We initially seek to describe the jet rebound regimes in tests conducted in the weightless environment of a drop tower. A parametric study reveals the dependence of the flow structure on the relevant dimensionless groups such as Reynolds number and Weber number defined on the velocity component perpendicular to the substrate. We show that significantly larger diameter jets behave similarly as much smaller jets demonstrated during previous terrestrial investigations is some parameter ranges while the flow is fundamentally different …

Opening Up Open Access Institutional Repositories To Demonstrate Value: Two Universities’ Pilots On Including Metadata-Only Records, Karen Bjork, Rebel Cummings-Sauls, Ryan Otto

Library Faculty and Staff Publications and Presentations

Introduction: Institutional repository managers are continuously looking for new ways to demonstrate the value of their repositories. One way to do this is to create a more inclusive repository that provides reliable information about the research output produced by faculty affiliated with the institution.

Description of Program: This article details two pilot projects that evaluated how their repositories could track faculty research output through the inclusion of metadata-only (no full-text) records. The purpose of each pilot project was to determine the feasibility and provide an assessment of the long-term impact on the repository’s mission statement, staffing, and collection development policies. …

Good Similar Patches For Image Denoising, Si Lu

Computer Science Faculty Publications and Presentations

Patch-based denoising algorithms like BM3D have achieved outstanding performance. An important idea for the success of these methods is to exploit the recurrence of similar patches in an input image to estimate the underlying image structures. However, in these algorithms, the similar patches used for denoising are obtained via Nearest Neighbour Search (NNS) and are sometimes not optimal. First, due to the existence of noise, NNS can select similar patches with similar noise patterns to the reference patch. Second, the unreliable noisy pixels in digital images can bring a bias to the patch searching process and result in a loss …

High-Speed Video From Asynchronous Camera Array, Si Lu

Computer Science Faculty Publications and Presentations

This paper presents a method for capturing high-speed video using an asynchronous camera array. Our method sequentially fires each sensor in a camera array with a small time offset and assembles captured frames into a high-speed video according to the time stamps. The resulting video, however, suffers from parallax jittering caused by the viewpoint difference among sensors in the camera array. To address this problem, we develop a dedicated novel view synthesis algorithm that transforms the video frames as if they were captured by a single reference sensor. Specifically, for any frame from a non-reference sensor, we find the two …

Systems Thinking As A Design Process, Elizabeth Lockwood

Systems Science Friday Noon Seminar Series

During my master’s degree I analyzed sustainable practices in the built environment. What came from that work was a deep level of understanding that the current practices and rating systems appeared to be technical approaches to a larger system at play. I realized I have a gift to see hidden connections and find links between systems. Currently I use systems mapping as part of the design process to unearth the hidden elements in a system. I believe it is important to understand where designers, clients and stakeholders can insert themselves into a system. Part of this understanding is having empathy …

Efficient And Scalable Event Tracing, Rupika Dikkala

University Honors Theses

In this work, I demonstrate that a time series database can be utilized to store Open Trace Format 2 (OTF2) file metadata for common trace events efficiently and scalably. This paper examines the efficacy of storing event trace data in a time series database, and investigates associated performance overhead compared to the state of the art method using OTF2 trace files. The sample traces used in this project are generated from a parallel hydrodynamic modeling code, Lulesh, developed at Lawrence Livermore National Laboratory. In my approach, I first cache common event trace metadata in InfluxDB, a contemporary time series database. …

Farmer Attitudes Toward Cooperative Approaches To Herbicide Resistance Management: A Common Pool Ecosystem Service Challenge, David E. Ervin, Elise H. Breshears, George B. Frisvold, Terrance M. Hurley, Katherine E. Dentzman, Jeffrey L. Gunsolus, Raymond A. Jussaume, Micheal D. K. Owen, Jason Norsworthy, Mustofa Mahmud Al Mamun, Wesley Everman

Environmental Science and Management Faculty Publications and Presentations

Dramatic growth in herbicide-resistant (HR) weeds in the United States threatens farm profitability and may undercut environmentally beneficial farming practices. When HR weeds move across farm boundaries due to ecological processes or human action, a common pool resource challenge emerges, requiring farmer cooperation to manage such weeds effectively. We investigate the scope for cooperative management using responses to a national survey on HR weed issues to test a recursive model of three preconditions for collective action: (1) concern about HR weeds migrating from nearby lands; (2) communication with neighbors about HR weeds; and (3) belief that cooperation is necessary for …

A Dendritic Transfer Function In A Novel Fully-Connected Layer, Mark Robert Musil

University Honors Theses

Dendritic branch operations in pyramidal neurons are well understood in-vivo but their potential as computational assets in deep neural networks has not been explored. The pre-processing which dendrites perform may be able to decrease the error of an artificial neuron because each dendrite serves as an independent filtering mechanism which may prevent false positives. In order to test this hypothesis, a fully-connected layer implementing the dendritic transfer function is defined and used to replace the final fully-connected layer used in a standard CNN (convolutional neural network). Results show that the defined algorithm is not able to predict better than chance …

Predicting Time To Dementia Using A Quantitative Template Of Disease Progression, Murat Bilgel, Bruno Jedynak

Portland Institute for Computational Science Publications

Introduction: Characterization of longitudinal trajectories of biomarkers implicated in sporadic Alzheimer's disease (AD) in decades prior to clinical diagnosis is important for disease prevention and monitoring.

Methods: We used a multivariate Bayesian model to temporally align 1369 AD Neuroimaging Initiative participants based on the similarity of their longitudinal biomarker measures and estimated a quantitative template of the temporal evolution cerebrospinal fluid (CSF) Aβ_1-42, p-tau_181p, and t-tau, hippocampal volume, brain glucose metabolism, and cognitive measurements. We computed biomarker trajectories as a function of time to AD dementia, and predicted AD dementia onset age in a …

Remote Sensing Of Water Use Efficiency And Terrestrial Drought Recovery Across The Contiguous United States, Behzad Ahmadi, Ali Ahmadalipour, Glenn Tootle

Civil and Environmental Engineering Faculty Publications and Presentations

Ecosystem water-use efficiency (WUE) is defined as the ratio of carbon gain (i.e., gross primary productivity; GPP) to water consumption (i.e., evapotranspiration; ET). WUE is markedly influential on carbon and water cycles, both of which are fundamental for ecosystem state, climate and the environment. Drought can affect WUE, subsequently disturbing the composition and functionality of terrestrial ecosystems. In this study, the impacts of drought on WUE and its components (i.e., GPP and ET) are assessed across the Contiguous US (CONUS) at fine spatial and temporal resolutions. Soil moisture simulations from land surface modeling are utilized to detect and characterize agricultural …

Sound Propagation, Reflection, And Its Relevance To Ultrasound Imaging, Thomas Allen, Alex Chally, Bradley Moser, Ralf Widenhorn

Physics Faculty Publications and Presentations

The labs presented here build on a simple speed of sound activity and models medical ultrasound imaging by demonstrating how multiple reflections propagate in a closed system. A short sound pulse is emitted into a pipe that is closed at one end and contains one or more partially reflecting surfaces within the pipe. The variety of reflections and transmissions that occur can be measured with a microphone at the pipe entrance.

Agenda, Portland State University

Winter Symposium

Agenda: 2019 Winter Symposium

Program Presentation, Portland State University

Winter Symposium

Symposium 2019 Program Presentation slides

The Selection Of Parameters In Debris Flow Modeling: A Sensitivity Study Using The Discrete Element Method, Cora Siebert

University Honors Theses

Many studies have examined runout behavior of debris flows on various slopes and in different environments, but few have explicitly modeled their coarse woody debris component. Simulating a coarse-grained debris flow snout including coarse woody debris can be achieved using discrete element modeling. Before modeling the entire system, each parameter that influences the model must be determined and analyzed. Using 5 m resolution IfSAR data from Sitka, Alaska as the control topography, I conducted a sensitivity analysis of the behavior of a single particle as it travels downslope. Parameters of relevance are normal and tangential contact stiffness, viscous damping coefficient, …

Interaction Of Climate Change With Restoration Action Maturation In An Urban Environment: Impacts To Salmon Habitat, Laura E. Mcmullen, Jon Walker, Chip Mcconnaha

Urban Ecosystem Research Consortium of Portland/Vancouver

A number of salmon utilize Portland’s urban waterways including Chinook and Coho, and steelhead trout. The City of Portland has implemented and planned numerous aquatic, riparian, and stormwater restoration actions to improve habitat for salmonids and other natives; and Portland is the first city to receive Salmon Safe Certification. We conducted an independent evaluation process as part of the certification to evaluate effects of restoration actions on habitat for salmonids in the context of an urban environment and climate change. We engaged a multi-party process to incorporate empirical data, spatial analysis, expert knowledge, and mathematical modeling into a holistic evaluation …

Urban Ecology & Conservation Symposium 2019: 17th Annual (Abstracts), Urban Ecosystem Research Consortium Of Portland/Vancouver

Urban Ecosystem Research Consortium of Portland/Vancouver

The UERC is a consortium of people from various universities and colleges, state and federal agencies, local governments, non-profit organizations and independent professionals interested in supporting urban ecosystem research and creating an information-sharing network of people that collect and use ecological data in the Portland/Vancouver area.

UERC Mission Statement:

To advance the state of the science of urban ecosystems and improve our understanding of them, with a focus on the Portland/Vancouver metropolitan region, by fostering communication and collaboration among researchers, managers and citizens at academic institutions, public agencies, local governments, non-profit organizations, and other interested groups.

The principal organizers span …

Metrics And Methods Used To Compare Student Performance Data In Chemistry Education Research Articles, Michael R. Mack, Cory Hensen, Jack Barbera

Chemistry Faculty Publications and Presentations

Quasi-experiments are common in studies that estimate the effect of instructional interventions on student performance outcomes. In this type of research, the nature of the experimental design, the choice in assessment, the selection of comparison groups, and the statistical methods used to analyze the comparison data dictate the validity of causal inferences. Therefore, gathering and reporting validity evidence in causal studies is of utmost importance, especially when conclusions have real policy implications for students and faculty, among other stakeholders. This review examines 24 articles that reported quantitative investigations of the effect of instructional interventions on performance-based outcomes conducted within undergraduate …

Comparison Of Microbial Communities In The Sediments And Water Columns Of Frozen Cryoconite Holes In The Mcmurdo Dry Valleys, Antarctica, Pacifica Sommers, John L. Darcy, Dorota L. Porazinska, Eli M. S. Gendron, Andrew G. Fountain, Felix Jacob Zamora, Kim Vincent, Kaelin M. Cawley, Adam J. Solon, Lara Vimercati, Jenna Ryder, Steven K. Schmidt

Geology Faculty Publications and Presentations

Although cryoconite holes, sediment-filled melt holes on glacier surfaces, appear small and homogenous, their microbial inhabitants may be spatially partitioned. This partitioning could be particularly important for maintaining biodiversity in holes that remain isolated for many years, such as in Antarctica. We hypothesized that cryoconite holes with greater species richness and biomass should exhibit greater partitioning between the sediments and water, promoting greater biodiversity through spatial niche partitioning. We tested this hypothesis by sampling frozen cryoconite holes along a gradient of biomass and biodiversity in the Taylor Valley, Antarctica, where ice-lidded cryoconite holes are a ubiquitous feature of glaciers. We …