Digital Commons Network^™

Torsion And Curvature In Continuously Defective Solid Crystals, Marek Z. Elźanowski

Mathematics and Statistics Faculty Publications and Presentations

I show how one can utilize the concept of a canonical connection on a homogeneous space to describe defectiveness of a continuous elastic crystal solid.

Five Ps (Policies, Practices, Power Structures, Places; And People): A Framework To Analyze Systemic Inequalities, Eva Thanheiser, Lisa Weasel, Idowu Ajibade, Larry Martinez, Gina Greco

Mathematics and Statistics Faculty Publications and Presentations

This chart is part of a framework to establish institutional equity and is part of the following National Science Foundation grant project:

The Spaces of Empowerment for Equity and Diversity: Advancement Through Access (SEE-DATA) project at Portland State University (PSU) aims to identify, understand, and improve the workplace experiences and retention of faculty in STEM fields who have been traditionally minoritized and marginalized based on gender, race/ethnicity, and other intersectional identities (e.g., sexual orientation, disability, socioeconomic status, national origin, immigrant status). The project will collect, analyze, and map data about faculty’s experiences at PSU to inform programs and policies that …

Poised For Change: University Students Are Positively Disposed Toward Food Waste Diversion And Decrease Individual Food Waste After Programming, Manar Arica Alattar, Jennifer L. Morse

Environmental Science and Management Faculty Publications and Presentations

Eaters (consumers of food) are responsible for 60% of waste along the food cycle in developed countries. Programs that target individual and household food waste behavior change are essential to addressing such waste. School cafeterias worldwide offer an opportune microcosm in which to educate on food and nutrition skills and change related behavior. No Scrap Left Behind, a cafeteria food waste diversion program, was developed, piloted, and assessed based on measures of both direct and indirect food waste behavior, and attitudes, knowledge, and emotions related to food waste. Participants had positive attitudes towards food waste reduction, engaged in food waste …

Occam Software (And Manual) For Reconstructability Analysis, Martin Zwick, Kenneth Willett, Joe Fusion, Heather Alexander

Complex Systems Faculty Publications and Presentations

OCCAM is a Discrete Multivariate Modeling (DMM) tool based on the methodology of Reconstructability Analysis (RA). As an acronym it stands for Organizational Complexity Computation and Modeling, and the name is also a reference (with a non-standard spelling) to Ockham’s Razor. The principal programmers of its current version have been Kenneth Willett, Joe Fusion, and Heather Alexander. Ken Willett totally rewrote earlier versions of OCCAM. His version was originally called “OCCAM3” to distinguish it from these earlier OCCAM incarnations; the “3” has finally been dropped.

OCCAM’s typical use is to analyze data involving a large number of discrete variables, but …

Reconstructability Analysis Of The Predictors Of Physical Functioning Status In Older Americans By Race And Ethnicity, Amanuel Melekin, Martin Zwick

Complex Systems Faculty Publications and Presentations

This paper demonstrates the use of reconstructability analysis to examine race/ethnic differences in physical functioning status among older Americans. Reconstructability analysis is an information theory and graph theory method which has been successfully used in multivariate data modeling. The health and retirement study data from 2004 are used for this demonstration. Out of eighteen independent variables included, seven variables appeared in the best models selected. Uncertainty reductions in physical functioning status were substantial across the models but the magnitudes and predictive variables varied slightly by race/ethnicity. Examination of the model probability distributions indicated that composite independent variable states of overlapping …

Pdxscholar Annual Report 2020, Karen Bjork, Sherry Buchanan, David Coate, Bertrand Robinson, Stacey Schlatter

Library Faculty and Staff Publications and Presentations

This report details the tenth year of operation for PDXScholar, Portland State University's institutional repository. The report covers the period between January 1, 2020 and December 31, 2020.

The 2020 report highlights the exponential growth of PDXScholar with almost 2.1 million (2,094,796) full text downloads. This is an increase of approximately 800,000 downloads from 2019, representing a 62% increase.

The report also focuses on our work to bring online new collections and to highlight research impacting our communities, academics, and personal lives.

An Examination Of Limiting Factors Of Chrysemys Picta Bellii (Western Painted Turtles) In The Lower Willamette River Basin, Oregon, James P. Holley

Environmental Science and Management Professional Master's Project Reports

Oregon’s two native freshwater turtle species, Chrysemys picta bellii (Western painted turtle) and Actinemys marmorata (Northwestern pond turtle), have seen significantly reduced population sizes since the founding of Portland in 1845, with estimates of up to 90% for A. marmorata. This project examined turtle nesting activity at 25 sites across a range of turtle populations and habitats around the Lower Willamette River Basin. All discovered turtle nesting activity was found in areas of high solar exposure. We found 93% of over 400 nest attempts to have been depredated across the 25 sites, well above most other reported rates. At …

Enthusiastic But Inconsistent: Graduate Teaching Assistants’ Perceptions Of Their Role In The Cure Classroom, Erin Shortlidge, Jessica R, Cary, Emma C. Goodwin

Biology Faculty Publications and Presentations

Despite growing evidence of positive student outcomes from course-based undergraduate research experiences (CUREs), little consideration has been given to employing graduate teaching assistants (GTAs) as CURE instructors. GTAs may be novice researchers and/or teachers and likely vary in their interest in teaching a CURE. Guided by expectancy-value theory, we explored how GTAs’ self-efficacy and values regarding teaching a CURE impact motivation and perceptions of their roles as CURE instructors. Using a multiple case study design, we interviewed nine GTAs who taught a network CURE at one research institution. Though most GTAs held a relatively high value for teaching a CURE …

Computational Form Exploration Of Branching Columns Using Concepts Of Formex Algebra And The Paragen Method, Peter Von Buelow, Anahita Khodadadi

School of Architecture Faculty Publication and Presentations

This study addresses the relationship between the geometry and structural performance of branching columns using an example case based on a square grid shell supported by four branching columns. The branching columns are configured with three levels of members, bifurcating into four members as each member branches upwards. A range of solutions is parametrically generated using the concepts of formex algebra and its associated software system, Formian 2.0. The form exploration uses the GAbased method, ParaGen which incorporates both quantitative structural performance and qualitative architectural considerations in the exploration process. Certain design constraints, as well as multiple objectives, are established …

View Synthesis Of Dynamic Scenes Based On Deep 3d Mask Volume, Kai-En Lin, Guowei Yang, Lei Xiao, Feng Liu, Ravi Ramamoorthi

Computer Science Faculty Publications and Presentations

Image view synthesis has seen great success in reconstructing photorealistic visuals, thanks to deep learning and various novel representations. The next key step in immersive virtual experiences is view synthesis of dynamic scenes. However, several challenges exist due to the lack of high-quality training datasets, and the additional time dimension for videos of dynamic scenes. To address this issue, we introduce a multi-view video dataset, captured with a custom 10-camera rig in 120FPS. The dataset contains 96 high-quality scenes showing various visual effects and human interactions in outdoor scenes. We develop a new algorithm, Deep 3D Mask Volume, which enables …

On The (Im)Practicality Of Adversarial Perturbation For Image Privacy, Arezoo Rajabi, Rakesh B. Bobba, Mike Rosulek, Charles Wright, Wu-Chi Feng

Computer Science Faculty Publications and Presentations

Image hosting platforms are a popular way to store and share images with family members and friends. However, such platforms typically have full access to images raising privacy concerns. These concerns are further exacerbated with the advent of Convolutional Neural Networks (CNNs) that can be trained on available images to automatically detect and recognize faces with high accuracy.

Recently, adversarial perturbations have been proposed as a potential defense against automated recognition and classification of images by CNNs. In this paper, we explore the practicality of adversarial perturbation based approaches as a privacy defense against automated face recognition. Specifically, we first …

Towards Formally Verified Compilation Of Tag-Based Policy Enforcement, Chr Chhak, Andrew Tolmach, Sean Anderson

Computer Science Faculty Publications and Presentations

Hardware-assisted reference monitoring is receiving increasing attention as a way to improve the security of existing software. One example is the PIPE architecture extension, which attaches metadata tags to register and memory values and executes tag-based rules at each machine instruction to enforce a software-defined security policy. To use PIPE effectively, engineers should be able to write security policies in terms of source-level concepts like functions, local variables, and structured control operators, which are not visible at machine level. It is the job of the compiler to generate PIPE-aware machine code that enforces these source-level policies. The compiler thus becomes …

The Case For A Long-Lived And Robust Yellowstone Hotspot, Victor E. Camp, Ray E. Wells

Geology Faculty Publications and Presentations

The Yellowstone hotspot is recognized as a whole-mantle plume with a history that extends to at least 56 Ma, as recorded by offshore volcanism on the Siletzia oceanic plateau. Siletzia accreted onto the North American plate at 51–49 Ma, followed by repositioning of the Farallon trench west of Siletzia from 48 to 45 Ma. North America overrode the hotspot, and it transitioned from the Farallon plate to the North American plate from 42 to 34 Ma. Since that time, it has been genetically associated with a series of aligned volcanic provinces associated with ageprogressive events that include Oligocene high-K calc-alkaline …

Toward An Integrative Geological And Geophysical View Of Cascadia Subduction Zone Earthquakes, Maureen A.L. Walton, Lydia M. Staisch, Tina Dura, Jessie K. Pearl, Brian Sherrod, Joan Gomberg, Simon Engelhart, Ray E. Wells, Multiple Additional Authors

Geology Faculty Publications and Presentations

The Cascadia subduction zone (CSZ) is an exceptional geologic environment for recording evidence of land-level changes, tsunamis, and ground motion that reveals at least 19 great megathrust earthquakes over the past 10 kyr. Such earthquakes are among the most impactful natural hazards on Earth, transcend national boundaries, and can have global impact.Reducing the societal impacts of future events in the US Pacific Northwest and coastal British Columbia, Canada, requires improved scientific understanding of megathrust earthquake rupture, recurrence, and corresponding hazards. Despite substantial knowledge gained from decades of research, large uncertainties remain about the characteristics and frequencies of past CSZ earthquakes. …

Inventory Of Rock Glaciers In The American West And Their Topography And Climate, Allison Reese Trcka

Dissertations and Theses

Rock glaciers are flowing geomorphic landforms composed of an ice/debris mixture. A uniform rock glacier classification scheme was created for the western continental US, based on internationally recognized criteria, to merge the various regional published inventories. A total of 2249 rock glaciers (1564 active, 685 inactive) and 7852 features of interest were identified in 10 states (WA, OR, CA, ID, NV, UT, ID, MT, WY, CO, NM). Sulfur Creek rock glacier in Wyoming is the largest active rock glacier (2.39 km²). The mean area and elevation for active and inactive rock glaciers are 0.18 km², 3384 …

Sensitivity Analysis Of An Agent-Based Simulation Model Using Reconstructability Analysis, Andey M. Nunes, Martin Zwick, Wayne Wakeland

Complex Systems Faculty Publications and Presentations

Reconstructability analysis, a methodology based on information theory and graph theory, was used to perform a sensitivity analysis of an agent-based model. The NetLogo BehaviorSpace tool was employed to do a full 2^k factorial parameter sweep on Uri Wilensky’s Wealth Distribution NetLogo model, to which a Gini-coefficient convergence condition was added. The analysis identified the most influential predictors (parameters and their interactions) of the Gini coefficient wealth inequality outcome. Implications of this type of analysis for building and testing agent-based simulation models are discussed.

Estimating Posterior Quantity Of Interest Expectations In A Multilevel Scalable Framework, Hillary R. Fairbanks, Sarah Osborn, Panayot S. Vassilevski

Mathematics and Statistics Faculty Publications and Presentations

Scalable approaches for uncertainty quantification are necessary for characterizing prediction confidence in large‐scale subsurface flow simulations with uncertain permeability. To this end we explore a multilevel Monte Carlo approach for estimating posterior moments of a particular quantity of interest, where we employ an element‐agglomerated algebraic multigrid (AMG) technique to generate the hierarchy of coarse spaces with guaranteed approximation properties for both the generation of spatially correlated random fields and the forward simulation of Darcy's law to model subsurface flow. In both these components (sampling and forward solves), we exploit solvers that rely on state‐of‐the‐art scalable AMG. To showcase the applicability …

Adaptive Courseware Implementation: Investigating Alignment, Course Redesign, And The Student Experience, Patricia O'Sullivan, Janelle De Carrico Voegele, Tonya Buchan, Raiza Dottin, Kari Goin Kono, Misty Hamideh, Wendy S. Howard, Jennifer Todd, Stanley Kruse, Johannes De Gruyter, Kevin Berg

Curriculum and Instruction Faculty Publications and Presentations

In this paper, four institutions share student and faculty feedback on the implementation of adaptive courseware through a common case study: biology for undergraduate non-majors. Additionally, each institution has provided a second case study of their choice. Together, researchers at Colorado State University in Fort Collins, CO, Portland State University in Portland, OR, University of Central Florida in Orlando, FL, and the University of Mississippi in Oxford, MS consider student perception of the benefits to the implementation of adaptive courseware, and how the deliberate alignment between adaptive courseware and course organization and structure impacts student experience. This paper highlights the …

Pharmaceuticals And Personal Care Products In Pacific Northwest Coastal Ecosystems: Spatial Variation, Organism Effects, And Consumer Perspectives, Amy Lynne Ehrhart

Dissertations and Theses

Anthropogenic pollution poses a threat to marine organisms and ecosystems worldwide. Common chemical pollutants that enter the marine environment include legacy contaminants, which are well known and heavily regulated or banned pollutants, and emerging contaminants, which are more recently recognized as pollutants and often lack regulatory limits for their use and discharge. Wastewater treatment plant (WWTP) effluent is a major source of various contaminants of concern, particularly pharmaceutical and personal care products (PPCPs) that are not fully removed during treatment. PPCPs exist at low concentrations in the environment and may have unknown and subtle effects on marine life. Data gaps …

An Exploration Of Teacher Preparation Practices With Foundational Knowledge Of Literacy, Marla K. Robertson Phd, Laurie A. Sharp, Roberta Raymond, Rebekah E. Piper Phd

Northwest Journal of Teacher Education

The Standards for the Preparation of Literacy Professionals 2017 published by the International Literacy Association provide the basis for high-quality literacy teacher preparation. This study used qualitative survey responses to explore the literacy practices that teacher educators use to promote understandings among preservice teachers for each grade-level band (i.e., Pre-K/Primary, Elementary/Intermediate, Middle/High School). The researchers used conceptualizations of teacher knowledge as a theoretical lens to better understand reported preparation practices. Data analysis revealed three themes: Teacher Educator Pedagogy, Course Content, Student and Program Expectations. Researchers posit that teacher educators do not evenly focus on all components of literacy and …

Is Kinesiology A Bridge To Stem Engagement? Sport Science Labs In High School, Judy A. Schultz, Robert W. Danielson, Robert D. Catena, Christopher P. Connolly, Kasee Hildenbrand

Northwest Journal of Teacher Education

Improving STEM education in schools is important to prepare students for the increasing number of STEM related jobs. As a STEM discipline, kinesiology, which includes the study of sport, exercise, movement and well-being, may be an effective link between science concepts and students’ everyday lives and thus may stimulate science engagement. Our university’s kinesiology programs developed a set of sport related kinesiology labs which were presented by faculty and students during one semester in local high school Freshmen and Senior science classes. Survey data included information about STEM engagement, scientific inquiry, and knowledge of kinesiology as a STEM field. Findings …

From Forests To Fish: Mercury In Mountain Lake Food Webs Influenced By Factors At Multiple Scales, Ariana M. Chiapella, Collin A. Eagles-Smith, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Mountain lakes, while seemingly pristine, have been subjected to historical fish stocking practices and exposure to atmospherically deposited contaminants like mercury. Mercury bioaccumulation in these ecosystems varies widely due to strong environmental gradients, and there are complex, hierarchical factors that affect mercury transport and loading, methylmercury production, and food web biomagnification. We sought to assess how representative variables associated with watershed, lake, and food web-scale processes—specifically, catchment tree cover, lake benthic primary production, and fish diet, respectively—are associated with mercury concentrations in mountain lake fish. Mean fish mercury concentrations varied threefold between lakes, with nearshore tree cover and fish diet …

Relationships Between In-Situ Tests And Soil Cyclic Strength For Earthquake Hazard Characterization In The Pacific Northwest, Tanner Scott Bryantt

Dissertations and Theses

Strong earthquake shaking is a natural hazard threat in the Pacific Northwest. Soil failure due to strong earthquake shaking -- known as cyclic soil failure or liquefaction -- is expected to cause large ground deformations and damage to roads, bridges, and other civil infrastructure. Cyclic soil strength (CRR) is often characterized with in-situ geotechnical tests including the cone penetration test (CPT). Relationships between CRR and in-situ test data are not well established for soils in the Pacific Northwest. Portland State University, in partnership with New Albion Geotechnical has compiled a database of cyclic lab tests for Pacific Northwest soils to …

New Perspectives On Johannes De Muris And His Notitia Artis Musicae, Jeffrey Allan Arnsdorf

Dissertations and Theses

At the end of the 1310s, Norman mathematician and astronomer Johannes de Muris (c. 1295-after 1344) reconceived the existing musical notation system on a mathematical foundation. His Notitia artis musicae dramatically increased the fidelity with which the system could represent complex rhythmic patterns. In recent years, musicologists, particularly Karen Desmond, have begun to incorporate the scholarship of historians of astronomy in their work on Muris and the Notitia. These studies take as their focus conceptual shifts in music theory and practice. This thesis repositions the perspective to Muris himself, seeking to shed light on his intention in writing the …

Vessel Trajectory Prediction Using Historical Ais Data, Jagir Laxmichand Charla

Dissertations and Theses

Maritime vessel position coordinates are important information for maritime situational planning and organization. A better estimate of future locations of the maritime vessels, from their current locations, can help maritime authorities to make planned decisions, which can be helpful to avoid traffic congestion and longer waiting times. This thesis develops a method for estimating future locations of the vessels using their current and previous locations and other data.

The motivating scenario for this work is that of determining the future locations of the vessels based on their current location and previous locations for accurate modelling of underwater acoustic noise. As …

Wildfire Risk Assessment For A Municipal Watershed In Western Oregon, Usa: Methods For Projecting The Impact Of Mid-21st Century Climate Change On Wildfire Hazard, Andy Mcevoy

Dissertations and Theses

In the western United States, climate change is projected to lead to significant changes in regional wildfire regimes. Historically, forests west of the Cascade crest in Oregon and Washington, USA (westside) have been characterized by low-frequency wildfire events, but climate change projections indicate that wildfire could become a more common disturbance, altering ecological processes and impairing ecosystem services like surface water quality and quantity. Wildfire risk assessments based on simulation models have been used in high frequency fire regimes to evaluate contemporary and future risk, but present unique challenges in westside forests because characteristic low annual burn probabilities result in …

Investigating Dose-Dependent, Multi-Generational, And Strain-Specific Effects Of 17Α-Ethynylestradiol Exposure In Zebrafish (Danio Rerio), Decatur Mitochondria Foster

Dissertations and Theses

Endocrine disrupting chemicals (EDCs) pose a threat to biodiversity at the individual, population, and ecosystem level, as they can interfere with processes that are responsible for regulating metabolism, development, behavior, and reproduction in living organisms. 17α-ethynylestradiol (EE2) is a synthetic estrogen and EDC utilized in pharmaceutical and livestock industries, and contaminates waterways worldwide. This research explores the effects of dose-dependent and multi-generational exposure of EE2 in three strains of zebrafish. High dose (10-25 ng/L EE2) exposure led to complete reproductive failure, as well as significantly decreased survival and growth. A period in clean water (depuration) after exposure allowed for some …

Clustered Hyperspectral Target Detection, Sean Onufer Stalley

Dissertations and Theses

Aerial target detection is often used to search for relatively small things over large areas of land. Depending on the size and signature of the target, detection can be a very easy or very difficult task. By capturing images with several hundred color channels, hyperspectral sensors provide a new way of looking at this task, both literally and figuratively. Hyperspectral sensors can be used in many aerial target detection tasks such as identifying unhealthy trees in a forest, searching for minerals at a mining site, or finding the sources of chemical leaks at a factory. The high spectral resolution of …

Identification Of Degradation Products Formed From Glycerol And Terpenes In Aromatherapy Vaporizers, Alisha Ortiz

University Honors Theses

Degradation chemistry has been widely studied to assess the safety of aerosols in many fields. The study herein investigates the degradation products formed from MONQ personal aromatherapy devices- a new non-nicotine aromatherapy vape pen device on the market. These pens are marketed to alleviate symptoms of an unrecognized medical syndrome called “terpene deficiency”. These pens contain a glycerin (GL), or glycerol (VG), base and a blend of terpene-rich essential oils. Previous studies have investigated the degradation of both VG and terpenes and have shown that concerning compounds are released in the gas phase, including benzene, benzaldehyde, methacrolein and methyl vinyl …

Entrainment Processes For A Jet In Cross-Flow: The Quantification Of Turbulent Contributions And Their Importance On Accurate Modeling, Graham Asher Freedland

Dissertations and Theses

A jet in cross flow (JICF) is examined experimentally by injecting a stream of air into crossing fluid with an aim into quantifying entrainment process and downstream evolution. The behavior of JICF is important to fields ranging from turbine-blade cooling to smokestack pollution and volcanic eruption dynamics. Existing simplified volcanic plume models are tested; most importantly, the near-field contributions of complex interconnected vortex systems, which present significant uncertainties because they assume negligible turbulence. While jets in irrotational cross-flow have been investigated, this analysis has focused on the interaction between a turbulent jet in low and highly turbulent cross-flow created by …