Digital Commons Network^™

An Operational Drought Prediction Framework With Application Of Vine Copula Functions, Mahkameh Zarekarizi

Student Research Symposium

Early and accurate drought predictions can benefit water resources and emergency managers by enhancing drought preparedness. Soil moisture memory is shown to contain helpful information for prediction of future values. This study uses the soil moisture memory to predict their future states via multivariate statistical modeling. We present a drought forecasting framework which issues monthly and seasonal drought forecasts. This framework estimates droughts with different lead times and updates the forecasts when more data become available. Forecasts are generated by conditioning future soil moisture values on antecedent drought status. The statistical model is initialized by soil moisture simulations retrieved from …

Bayesian Optimization For Refining Object Proposals, With An Application To Pedestrian Detection, Anthony D. Rhodes

Student Research Symposium

We devise an algorithm using a Bayesian optimization framework in conjunction with contextual visual data for the efficient localization of objects in still images. Recent research has demonstrated substantial progress in object localization and related tasks for computer vision. However, many current state-of-the-art object localization procedures still suffer from inaccuracy and inefficiency, in addition to failing to successfully leverage contextual data. We address these issues with the current research.

Our method encompasses an active search procedure that uses contextual data to generate initial bounding-box proposals for a target object. We train a convolutional neural network to approximate an offset distance …

Fe Analysis Of Alternative Thermal Breaks For Steel Buildings, Salih Q. Mahmood

Student Research Symposium

“Thermal bridge” is a term used for structural or non-structural elements that have higher heat transfer than any other elements or spots in the building envelope, reducing the efficiency of the building thermal insulation. About 20% of the heat occurs via such thermal bridges. Thermal insulations (thermal breaks) are used within a steel connection to mitigate the effect of thermal bridges. In this research, connections with steel fillers studied by Dusicka (2007) were simulated using the finite element (FE) program ABAQUS. The results from the FE model were validated with those from the experimental work done by Dusicka (2007) and …

Performance Analysis Of Droughthpc, Yasodhadevi Nachimuthu

Student Research Symposium

We present our performance analysis of DroughtHPC, a software application being developed by an interdisciplinary effort lead by Dr.Moradkhani in the Civil Engineering department, Dr. Daescu in the Math Department, and Dr. Karavanic in the Computer Science Department.

The DroughtHPC application is used to predict drought conditions for a target geographical area. The data used in the prediction are soil conditions, vegetation layers, canopy cover, snow accumulation information from satellites, and meteorological data. DroughtHPC is written in Python and uses two hydrologic models, PRMS [1] and VIC [2], to simulate soil moisture levels. A larger geographical area such as the …

Quasi-Optical Measurement For Low Loss Material Characterization In Submillimeter Wave Range, Ha Khiem Tran, Thanh Ngoc Dan Le, Branimir Pejcinovic

Student Research Symposium

An accurate knowledge of dielectric constant of materials is required in many sub-millimeter wave applications. Free-space measurement of materials has always been one of the first choices due to their non-destructive nature and relatively simple sample preparation. However, free-space measurement systems at sub-millimeter frequency range suffer from two main problems: high loss because of divergent beam pattern and diffraction when the beam waist of the radiated beam is relatively large compared to the size of the sample under tests. In order to mitigate these issues, we set up a quasi-optical system using off-axis parabolic mirrors, which enhance the dynamic range …

Cox Processes For Visual Object Counting, Yongming Ma

Student Research Symposium

We present a model that utilizes Cox processes and CNN classifiers in order to count the number of instances of an object in an image. Poisson processes are well suited to events that occur randomly in space, like the location of objects in an image, as well as to the task of counting. Mixed Poisson processes also offer increased flexibility, however they do not easily scale with image size: they typically require O(n3) computation time and O(n2) storage, where n is the number of pixels. To mitigate this problem, we employ Kronecker algebra which takes advantage of the direct product …

The Importance Of Urban Habitat Connectivity And Influence On Native Avian Species And Community Science, Kristen S. Gulick

Student Research Symposium

In what ways do small-scale urban backyards contribute to local bird abundance and biodiversity? In what ways might these yards serve as an ‘extension’ of neighboring native forest areas? This project investigates the contribution that a group of backyards, certified through the Backyard Habitat Certification Program, have in the suburb of Hillsdale, Oregon, which is adjacent to the natural area of Keller Woodland. Backyard owners functioning as citizen or community scientists assisted with conducting residential bird point-counts once a week in each backyard and the natural area. Counts were done for a total of 8 weeks during nesting season to …

Finite Element Method Analysis Of Resonant Cavity For Whispering Gallery Acoustic Sensing Microscopy, Thanh N.D. Le, Ha Tran, Andres H. La Rosa

Student Research Symposium

Whispering Gallery Acoustic Sensing (WGAS) has been studied by Department of Physics at Portland State University as a mean of controlling sample to probe distance in tuning-folk-based scanning probe microscopy (TF-SPM). WGAS uses the microscope frame as a resonance acoustic cavity. The setup shows high potential because of high-quality factor nature of acoustic cavity as well as using mechanical motions of the TF itself instead of electrical signals. However, the analytic solution of the eigenfrequencies of the current microscope frame is very complex due to the asymmetric geometry. The purpose of this study is to use finite element method to …

Monitoring Of Applied Stress In Concrete Using Ultrasonic Full-Waveform Comparison Techniques, Ali Hafiz

Student Research Symposium

Ultrasonic testing is a non-destructive approach commonly used to evaluate concrete structures. A challenge with concrete is that it is heterogeneous, which causes multiple wave scattering resulting in longer and more complex wave paths. The recorded ultrasonic waveform can be divided into two portions: the coherent (or early) and the diffuse (or Coda) portion. While conventional methods only use the coherent portion, e.g. the first wave arrival to determine the wave velocity, we are interested in the entire waveform, i.e. until the wave amplitude is completely dampened out. The objective of this study was to determine what portion of the …

Non-Native Mangroves Of Moloka'i, Hawai'i: A Socio-Ecological Analysis, Casey Lewis

Student Research Symposium

Invasive species are recognized as a leading threat to ecosystems and their management is expensive, time consuming, and labor intensive. Therefore, it is important to review both benefits and detriments of the species to inform appropriate management decisions. Red mangrove was introduced to Moloka'i, Hawaii in 1902 to mitigate the effects of soil erosion and has since spread along the coast and to adjacent islands creating novel habitat. This study assessed both biological services and social attitudes towards Moloka'i's non-native mangroves to provide a comprehensive evaluation of the species. Zooplankton community structure was examined in mangrove and non-mangrove sites and …

Mindfulness Meditation As A Stress Reactivity Intervention: An Event-Related Potential Study, Jessica L. Trottier, Barry S. Oken

Student Research Symposium

The biological and neural mechanisms of stress have been extensively studied and supported, but are still unclear. Event-related potentials (ERP’s) emitted by neurons in the brain are a useful tool in measuring stress because they reflect neural response in real-time, to the millisecond, versus typical biological markers, which are typically evaluated before and after a stress test. The neurobiological relationship between ERP’s and stress originates in the anterior cingulate cortex, which in turn activates the hypothalamic–pituitary–adrenal axis; the main physiological cascade fueling the stress response and its chronically harmful symptoms. Malfunctions in the stress response, as in the cases of …

Compositional Practice As Expression Of Cultural Hybridity In Lou Harrison’S Double Concerto For Violin, Cello, And Javanese Gamelan, Matthew N. Andrews

Student Research Symposium

Artists in the twenty-first century face a creative dilemma: styles and traditions from around the world are now available to all, and in the post-colonial era it can become difficult to discern the appropriateness of artistic borrowings. I propose that cultural hybridity, defined as genuine investment in another artistic culture's traditions and respect for its practitioners, can provide an “Ariadne's thread” to guide the interculturally sensitive artist. Lou Harrison's long relationship with the gamelan music (karawitan) of Indonesia provides an enlightening example. From his initial exposure to Asian music all through his decades of intensive study and instrument-building, Harrison's development …

Assistive Technology For The Cognitively Impaired: A Study Of Literacy, Comprehension, And The Print Publishing Industry, Amanda Matteo

Student Research Symposium

This paper explores how the print publishing industry has developed to include and assist children with cognitive impairments. It analyzes the ways in which assistive technology and the digital market (i.e. ebooks) have promoted reading comprehension amongst this population, and discusses what further developments are in the works in regards to cognitive reading enhancements. Finally, it explores the areas in which this development is still limited and provides potential, attainable solutions.

Forecasted Range Shifts Of Arid-Land Fishes In Response To Climate Change, James E. Whitney, Joanna B. Whittier, Craig Patrick Paukert, Julian D. Olden, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Climate change is poised to alter the distributional limits, center, and size of many species. Traits may influence different aspects of range shifts, with trophic generality facilitating shifts at the leading edge, and greater thermal tolerance limiting contractions at the trailing edge. The generality of relationships between traits and range shifts remains ambiguous however, especially for imperiled fishes residing in xeric riverscapes. Our objectives were to quantify contemporary fish distributions in the Lower Colorado River Basin, forecast climate change by 2085 using two general circulation models, and quantify shifts in the limits, center, and size of fish elevational ranges according …

Behavior-Based Freight Modeling At Metro, Chris Johnson, Bud Reiff

PSU Transportation Seminars

Chris Johnson and Bud Reiff will present on a behavior-based freight model being used at Oregon Metro. This model will replace Metro’s current truck model with a hybrid freight model that both represents multi-modal freight flows through elements of national and regional supply chains and simulates the movement of individual trucks and shipments on local networks. Model estimation and calibration will also require collection of behavioral data from shippers and receivers representing a wide range of industries, common and contract freight carriers, business that operate non-freight commercial vehicles, warehouse managers, and logistics agents.

Key project objectives:

• Develop tools to enable …

Leed O+M Materials Audit: Blumel Hall, Emily Murkland, Taylor Stone, John Dea, Kristen Purdy

Campus Sustainability Office Publications, Reports and Presentations

• This report provides the Campus Sustainability Office with an objective, third party Materials Audit for Blumel Hall in Portland, Oregon. The data collected for this audit provides Campus Sustainability Office with insight into Blumel’s current waste composition and diversion rate as well as identifies opportunities to improve recycling, composting, and areas for reduction of materials consumption. Community Environmental Services (CES) conducted Materials Audits for 100% of Blumel Hall’s landfill-bound, commingled recycling, glass bottles and jars recycling, and compost streams during a 24-hour period.

Competition Amplifies Drought Stress In Forests Across Broad Climatic And Compositional Gradients, Kelly E. Gleason, John B. Bradford, Alessandra Bottero, Anthony W. D'Amato, Shawn Fraver, Brian J. Palik, Michael A. Battaglia, Louis Iverson, Laura Kenefic, Christel C. Kern

Environmental Science and Management Faculty Publications and Presentations

Forests around the world are experiencing increasingly severe droughts and elevated competitive intensity due to increased tree density. However, the influence of interactions between drought and competition on forest growth remains poorly understood. Using a unique dataset of stand-scale dendrochronology sampled from 6405 trees, we quantified how annual growth of entire tree populations responds to drought and competition in eight, long-term (multi-decadal), experiments with replicated levels of density (e.g., competitive intensity) arrayed across a broad climatic and compositional gradient. Forest growth (cumulative individual tree growth within a stand) declined during drought, especially during more severe drought in drier climates. Forest …

Evidence For Distributed Clockwise Rotation Of The Crust In The Northwestern United States From Fault Geometries And Focal Mechanisms, Thomas M. Brocher, Ray E. Wells, Andrew P. Lamb, Craig S. Weaver

Geology Faculty Publications and Presentations

Paleomagnetic and GPS data indicate that Washington and Oregon have rotated clockwise for the past 16 Myr. Late Cenozoic and Quaternary fault geometries, seismicity lineaments, and focal mechanisms provide evidence that this rotation is accommodated by north directed thrusting and right-lateral strike-slip faulting in Washington, and SW to W directed normal faulting and right-lateral strike-slip faulting to the east. Several curvilinear NW to NNW trending high-angle strike-slip faults and seismicity lineaments in Washington and NW Oregon define a geologic pole (117.7°W, 47.9°N) of rotation relative to North America. Many faults and focal mechanisms throughout northwestern U.S. and southwestern British Columbia …

Working Together Differently: Addressing The Housing Crisis In Oregon, Judith A. Ramaley

Public Administration Faculty Publications and Presentations

Universities are being asked to prepare our students to navigate successfully in a complex and interconnected world and to contribute to the solution of difficult problems at work and in the communities where they live. Our universities must do the same. We must adapt our approaches to education, scholarship and community involvement in order to play a meaningful role in addressing the increasingly complex and wicked problems that our communities face. The housing crisis in Portland, Oregon offers an especially important example of a wicked problem that has developed slowly, will be very costly to resolve and involves a lot …

Using An Altimeter-Derived Internal Tide Model To Remove Tides From In Situ Data, Edward D. Zaron, Richard D. Ray

Civil and Environmental Engineering Faculty Publications and Presentations

Internal waves at tidal frequencies, i.e., the internal tides, are a prominent source of variability in the ocean associated with significant vertical isopycnal displacements and currents. Because the isopycnal displacements are caused by ageostrophic dynamics, they contribute uncertainty to geostrophic transport inferred from vertical profiles in the ocean. Here it is demonstrated that a newly developed model of the main semidiurnal (M2) internal tide derived from satellite altimetry may be used to partially remove the tide from vertical profile data, as measured by the reduction of steric height variance inferred from the profiles. It is further demonstrated that the internal …

English Learners' Positioning During Interactions With Monolingual English-Speaking Students, Amanda Sugimoto, Kathy Carter

Curriculum and Instruction Faculty Publications and Presentations

Increasingly, English Learners (ELs) are being educated in mainstream classrooms alongside English fluent students. Using a positioning theory framework, this multiple case study explored how ELs reflexively positioned themselves during interactions with their peers as well as how English fluent peers interactionally positioned ELs. Drawing upon multiple data sources, (i.e., observations, interviews, and artifacts), and using cross case analysis techniques, we found that ELs’ reflexive positioning was influenced by their language history and schooling context and peers’ interactional positioning moves limited ELs’ access to academic interactions. These findings pose important considerations regarding the academic and linguistic access of ELs in …

Simplified Reversed Chloroquines To Overcome Malaria Resistance To Quinoline-Based Drugs, Bornface Gunsaru, Steven J. Burgess, Westin Morrill, Jane X. Kelly, Shawheen Shomloo, Martin J. Smilkstein, Katherine May Liebman, David H. Peyton

Chemistry Faculty Publications and Presentations

Building on our earlier work of attaching a chemosensitizer (reversal agent) to a known drug pharmacophore, we have now expanded the structure-activity relationship study to include simplified versions of the chemosensitizer. The change from two aromatic rings in this head group to a single ring does not appear to detrimentally affect the antimalarial activity of the compounds. Data from in vitro heme binding and beta-hematin inhibition assays suggest that the single aromatic RCQ compounds retain activities against Plasmodium falciparum similar to those of CQ, although other mechanisms of action may be relevant to their activities.

Psu Urban Center Building Leed Eb Materials Audit Report, Emily Murkland, Taylor Stone, John Dea, Kristen Purdy

Campus Sustainability Office Publications, Reports and Presentations

This report provides the Campus Sustainability Office with an objective, third party Materials Audit for Portland State University’s Urban Center Building in Portland, Oregon. The data collected for this audit provides Campus Sustainability Office with insight into Urban Center’s current waste composition and diversion rate as well as identifies opportunities to improve recycling, composting, and areas for reduction of materials consumption. Community Environmental Services (CES) conducted materials audits for 100% of Urban Center’s landfill-bound, commingled recycling, glass bottles and jars recycling, and compost streams during a 24-hour period.

Continental-Scale Homogenization Of Residential Lawn Plant Communities, Megan M. Wheeler, Christopher Neill, Peter M. Groffman, Meghan Avolio, Neil D. Bettez, Jeannine Cavender-Bares, Rinku Roy Chowdhury, Lindsay Darling, J. Morgan Grove, Sharon J. Hall, James B. Heffernan, Sarah E. Hobbie, Kelli L. Larson, Jennifer L. Morse, Kristen C. Nelson, Laura A. Ogden, Jarlath O'Neil-Dunne, Diane E. Pataki, Colin Polsky, Meredith Steele, Tara Trammell

Environmental Science and Management Faculty Publications and Presentations

Residential lawns are highly managed ecosystems that occur in urbanized landscapes across the United States. Because they are ubiquitous, lawns are good systems in which to study the potential homogenizing effects of urban land use and management together with the continental-scale effects of climate on ecosystem structure and functioning. We hypothesized that similar homeowner preferences and management in residential areas across the United States would lead to low plant species diversity in lawns and relatively homogeneous vegetation across broad geographical regions. We also hypothesized that lawn plant species richness would increase with regional temperature and precipitation due to the presence …

Gas Transfer Velocities In Small Forested Ponds, Meredith A. Holgerson, Emily R. Farr, Peter A. Raymond

Environmental Science and Management Faculty Publications and Presentations

Inland waters actively exchange gases with the atmosphere, and the gas exchange rate informs system biogeochemistry, ecology, and global carbon budgets. Gas exchange in medium- to large-sized lakes is largely regulated by wind; yet less is known about processes regulating gas transfer in small ponds where wind speeds are low. In this study, we determined the gas transfer velocity, k₆₀₀, in four small ( < 250 m² ) ponds by using a propane ( C₃H₈ ) gas injection. When estimated across 12 h periods, the average k₆₀₀ ranged from 0.19 to 0.72 m d^-1 across …

Environmental Dna (Edna) Detects The Invasive Crayfishes Orconectes Rusticus And Pacifastacus Leniusculus In Large Lakes Of North America, Eric R. Larson, Mark A. Renshaw, Crysta Gantz, John Umek, Sudeep Chandra, David M. Lodge, Scott P. Egan

Environmental Science and Management Faculty Publications and Presentations

We report results of a study that made reciprocal comparisons of environmental DNA (eDNA) assays for two major invasive crayfishes between their disparate invasive ranges in North America. Specifically, we tested for range expansions of the signal crayfish Pacifastacus leniusculus (Dana, 1852) into the Laurentian Great Lakes region known to be invaded by the rusty crayfish Orconectes rusticus (Girard, 1852), as well as for the invasion of O. rusticus into large lakes of California and Nevada, US known to be invaded by P. leniusculus. We compared eDNA detections to historic localities for O. rusticus within the Great Lakes, and to …

From Deliberative Democracy To Communicative Democracy In The Classroom. A Response To “Education For Deliberative Democracy”, Lisa Weasel

Women, Gender, and Sexuality Studies Faculty Publications and Presentations

This response to Samuelsson’s typology for assessing deliberative democracy in classroom discussions views his analysis through an equity lens. It offers Young’s model of communicative democracy as a resource and argues that incorporating that model's emphasis on greeting, rhetoric, and storytelling into the typology can help to promote more equitable deliberative communication in the classroom. It offers specific tools, based on the author’s development of deliberative pedagogy in a biology classroom, that teachers can use across disciplines and educational settings to help promote more equitable deliberative communication in classroom discussions.

Response to Article
Martin Samuelsson, Education for Deliberative Democracy: A …

Essentials Of Building Virtual Instruments With Labview And Arduino For Lab Automation Applications, Jianghua Bai, Andres H. La Rosa

Physics Faculty Publications and Presentations

Four ways to improve the capabilities of a virtual instrument involving a microcontroller are covered in this paper. They are structural modeling and programming, real-time control, asynchronous communication between the microcontroller and the host PC, and system integration. This paper covers 4 common problems encountered by embedded developers and 5 solutions to the 4 problems. The solutions and examples demonstrated in this article will help readers build robust and reliable virtual instruments for crucial applications.

The Effect Of Plasma On Graphene Quality In An Inductively Couple Plasma Chemical Vapor Deposition Reactor, Brendan Coyne

Maseeh Summer Undergraduate Research Experience

Despite continued interest in research and application development, full scale graphene production is still limited by many factors including prohibitively high growth temperature requirements. Extremely high quality graphene growth is possible at high temperatures using chemical vapor deposition (CVD). Use of an inductively coupled plasma chemical vapor deposition (ICP CVD) reactor with the benefit of precursor gas decomposition through plasma generation, may provide possibility to reduce growth temperature. Herein, we report plasma’s effects on graphene growth by comparing growths of increasing power supplied to plasma generation and changes in precursor gas ratios. Plasma composition was characterized by ultraviolet and visible …

The Aerodynamic Effects On Flight Patterns And The Evolutionary Changes In Pterosaurs, Johnathan D. Talik

Maseeh Summer Undergraduate Research Experience

Early pterosaurs were the first vertebrates to achieve powered flight, and remained small-to-medium sized from the Triassic Period to the end of the Jurassic Period. During that interval, lasting from 210 million years ago to 66 million years ago, pterosaurs underwent a notable changes at the end of the Jurassic Period and through the Cretaceous Period. They were abruptly replaced by much larger forms, characterized by great size and peculiar head ornamentation, among other unique and notable morphological features. While many different explanations theorize why and how the features of the pterosaurs changed over the Cretaceous Period, the aerodynamic influences …