Digital Commons Network^™

Oregon State Rank Assessment For Bonneville Redside Shiner (Richardsonius Balteatus Hydrophlox), Misty Nelson

Institute for Natural Resources Publications

Oregon state conservation status assessment for Bonnevile redside shiner (Richardsonius balteatus hydrophlox) using NatureServe methodology, 2023.

Parameterized Complexity Of Feature Selection For Categorical Data Clustering, Sayan Bandyapadhyay, Fedor V. Fomin, Petr A. Golovach, Kirill Simonov

Computer Science Faculty Publications and Presentations

We develop new algorithmic methods with provable guarantees for feature selection in regard to categorical data clustering. While feature selection is one of the most common approaches to reduce dimensionality in practice, most of the known feature selection methods are heuristics. We study the following mathematical model. We assume that there are some inadvertent (or undesirable) features of the input data that unnecessarily increase the cost of clustering. Consequently, we want to select a subset of the original features from the data such that there is a small-cost clustering on the selected features. More precisely, for given integers ℓ (the …

Gated Recurrent Units For Blockage Mitigation In Mmwave Wireless, Ahmed H. Almutairi, Alireza Keshavarz-Haddad, Ehsan Aryafar

Computer Science Faculty Publications and Presentations

Millimeter-Wave (mmWave) communication is susceptible to blockages, which can significantly reduce the signal strength at the receiver. Mitigating the negative impacts of blockages is a key requirement to ensure reliable and high throughput mmWave communication links. Previous research on blockage mitigation has introduced several model and protocol based blockage mitigation solutions that focus on one technique at a time, such as handoff to a different base station or beam adaptation to the same base station. In this paper, we address the overarching problem: what blockage mitigation method should be employed? and what is the optimal sub-selection within that method? To …

The Discovery Of Diverse Picophytoplankton Populations In The Columbia And Willamette Rivers Using Flow Cytometry, Kylee M. Lamberson

Chemistry Undergraduate Departmental Honors Theses

As important primary producers, picophytoplankton determine the flow of carbon and energy in aquatic ecosystems. Picocyanobacteria are one picophytoplankton group known to be dominant in oceans and lakes, but they are still poorly understood in river systems. This project examined picophytoplankton communities in two distinct river systems: the Columbia and Willamette Rivers in Portland, Oregon. I aimed to characterize and quantify the picophytoplankton populations in the context of the environmental conditions of the two rivers. I used flow cytometry to detect cells based on their relative size and pigment fluorescence. I sampled nearly weekly for ten months to capture population …

Estimating Ocean Observation Impacts On Coupled Atmosphere-Ocean Models Using Ensemble Forecast Sensitivity To Observation (Efso), Chu-Chun Chang, Tse-Chun Chen, Eugenia Kalnay, Cheng Da, Safa Mote

Mathematics and Statistics Faculty Publications and Presentations

Ensemble Forecast Sensitivity to Observation (EFSO) is a technique that can efficiently identify the beneficial/detrimental impacts of every observation in ensemble-based data assimilation (DA). While EFSO has been successfully employed on atmospheric DA, it has never been applied to ocean or coupled DA due to the lack of a suitable error norm for oceanic variables. This study introduces a new density-based error norm incorporating sea temperature and salinity forecast errors, making EFSO applicable to ocean DA for the first time. We implemented the oceanic EFSO on the CFSv2-LETKF and investigated the impact of ocean observations under a weakly coupled DA …

The Effects Of Salt Marsh Restoration On The Hydrology Of Salt Marsh Channels, Isis Kontas

University Honors Theses

Salt marshes produce many ecosystem services, from water purification to protection from hurricanes. Despite their benefits, salt marshes have been impacted negatively by human activities. There are many salt marsh restoration projects that intend to bring back all ecological functions and services. Quantifiable measurements are needed to evaluate the effectiveness of such restoration efforts. Earlier work by Reagan Thomas demonstrated what happens to the hydrology of salt marsh channels when they are adjacent to restored salt marshes. This study builds on Thomas’ work and uses the sinuosity of channels as a quantitative, representative metric of salt marsh hydrology restoration effectiveness. …

Quantum Algorithms For Unate And Binate Covering Problems With Application To Finite State Machine Minimization, Abdirahman Alasow, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Covering problems find applications in many areas of computer science and engineering, such that numerous combinatorial problems can be formulated as covering problems. Combinatorial optimization problems are generally NPhard problems that require an extensive search to find the optimal solution. Exploiting the benefits of quantum computing, we present a quantum oracle design for covering problems, taking advantage of Grover’s search algorithm to achieve quadratic speedup. This paper also discusses applications of the quantum counter in unate covering problems and binate covering problems with some important practical applications, such as finding prime implicants of a Boolean function, implication graphs, and minimization …

Restricted Nonlinear Scales Of Turbulent Secondary Flows Over Spanwise Heterogeneous Roughness, Benjamin A. Minnick, Xiaowei Zhu, Dennice F. Gayme

Mechanical and Materials Engineering Faculty Publications and Presentations

Recent studies, e.g., Wangsawijaya et al. (2020) have revealed the prevalence of streak meandering in turbulent flow over spanwise heterogeneous roughness. Here we exploit the scale decomposition inherent in the Restricted Nonlinear (RNL) modeling approach to further investigate this behavior. The RNL decomposition comprises a large-scale streamwise averaged mean with small-scale fluctuations about that mean defined through a dynamical restriction that leads to computational tractability. The simplified setting facilitates the study of secondary flow interacting with the large-scale streak via one-way coupling, thus enabling additional insight into relevant interaction mechanisms. In agreement with the experimental work, our results indicate that …

An Efficient And Chemoselective Method To Generate Arynes, Bryan Metze, Riley A. Roberts, Aleksandra Nilova, David R. Stuart

Chemistry Faculty Publications and Presentations

Arynes hold immense potential as reactive intermediates in organic synthesis as they engage in a diverse range of mechanistically distinct chemical reactions. However, the poor functional group compatibility of generating arynes or their precursors has stymied their widespread use. Here, we show that generating arynes by deprotonation of an arene and elimination of an “onium” leaving group is mild, efficient and broad in scope. This is achieved by using aryl(TMP)iodonium salts (TMP = 2,4,6-trimethoxyphenyl) as the aryne precursor and potassium phosphate as the base, and a range of arynophiles are compatible. Additionally, we have performed the first quantitative analysis of …

Preparing Teaching Assistants To Facilitate Course-Based Undergraduate Research Experiences (Cures) In The Biological Sciences: A Call To Action, Erin Shortlidge, Amie M. Kern, Emma Goodwin, Jeffrey T. Olimpo

Biology Faculty Publications and Presentations

Course-based undergraduate research experiences (CUREs) offer an expanding avenue to engage students in real-world scientific practices. Increasingly, CUREs are instructed by graduate teaching assistants (TAs), yet TAs may be underprepared to facilitate and face unique barriers when teaching CUREs. Consequently, unless TAs are provided professional development (PD) and resources to teach CUREs effectively, they and their students may not reap the assumed benefits of CURE instruction. Here, we describe three perspectives – that of the CURE TA, the CURE designer/facilitator, and the CURE student – that are collectively intended to inform the development of tentative components of CURE TA PD. …

An Exploration Of Two Information Literacy Open Learning Object Repositories: Value, Content, And Engagement, Tiffanie Lynn Ford-Baxter

Communications in Information Literacy

Information literacy (IL) open learning object repositories (LORs) provide a space for librarians to find and exchange instruction resources and lessons. Given many librarians enter the workforce with little or no formal training or educational opportunities to learn about pedagogy, these repositories are indispensable resources to the Library and Information Science field. This study explored the contents of two popular IL LORs, Project Cora and the Association of College and Research Libraries Framework for Information Literacy Sandbox, to uncover how users engage with the resources and how the repositories differ. This study's findings suggest that while resources within the LORs …

Coastal Wetland Restoration Through The Lens Of Odum's Theory Of Ecosystem Development, Friedrich W. Keppeler, Annette S. Engel, Linda M. Hooper-Bùi, Paola C. López-Duarte, Charles W. Martin, Jill A. Olin, Katelyn J. Lamb, Michael J. Polito, Nancy N. Rabalais, Multiple Additional Authors

Environmental Science and Management Faculty Publications and Presentations

Advancing ecological restoration assessments requires a more detailed consideration of species interactions and ecosystem processes. Most restoration projects rely on a few metrics not always directly linked with ecological theory. Here, we used Odum's theory of ecosystem development to assess and compare the ecosystem structure and services of created marshes (4–6 years old) with preexisting, reference marshes in a brackish water region of the Mississippi River Delta. We built ecosystem models for created and reference marshes that integrated large datasets of stomach contents, stable isotopes, and taxa abundances. Despite strong resemblance in community structure, created marshes were at an earlier …

How Beavers (Castor Canadensis) Affect Habitat Availability For Two Native Oregon Turtles: Actinemys Marmorata And Chrysemys Picta Bellii, Rodé Krige

University Honors Theses

Oregon is home to two native freshwater turtle species: the northwestern pond turtle and the western painted turtle. Both turtles are Oregon conservation strategy species with a status rating of sensitive, indicating declining populations. Oregon's decline in these turtle's populations is thought to be predominantly due to loss and degradation of habitat that results from development and urbanization. Beavers' ability to dam streams and create ponds may be creating habitat usable by turtles, but the relationship is under-studied. This study assessed water temperature, basking habitat, and overall turtle habitat suitability at beaver-dammed and control ponds in Portland, Oregon. Average basking …

Chemical Strategies To Mitigate Electrostatic Charging During Coffee Grinding, Joshua Méndez Harper, Christopher H. Hendon

Electrical and Computer Engineering Faculty Publications and Presentations

The process of grinding coffee generates particles with high levels of electrostatic charge, causing a number of detrimental effects including clumping, particle dispersal, and spark discharge. At the brewing level, electrostatic aggregation between particles affects liquid-solid accessibility, leading to variable extraction quality. In this study, we quantify the effectiveness of four charge mitigation strategies. Our data suggests that adding small amounts of water to whole beans pre-grinding, or bombarding the grounds with ions produced from a high-voltage ionizer, are capable of de-electrifying the granular flows. While these techniques helped reduce visible mess, only the static reduction through water inclusion was …

2023 Aquatic Weed Surveys At Timothy Lake, Lake Harriet, North Fork Reservoir, And Estacada Lake, Gabriel E. Campbell, Jacob Rose

Center for Lakes and Reservoirs Publications and Presentations

Portland General Electric (PGE) operates and manages reservoirs as part of their Clackamas Hydroelectric Project in Clackamas County, Oregon. The Center for Lakes and Reservoirs staff surveyed some of these reservoirs in 2023 for aquatic vegetation. This document summarizes their survey efforts including their protocols and data.

Province-Wide Tapping Of A Shallow, Variably Depleted, And Metasomatized Mantle To Generate Earliest Flood Basalt Magmas Of The Columbia River Basalt, Northwestern Usa, Martin J. Streck, Luke James Fredenberg, Lena M. Fox, Emily B. Cahoon, Mary J. Mass

Geology Faculty Publications and Presentations

The Miocene Columbia River Basalt Group (CRBG) of the Pacific Northwest of the United States is the world’s youngest and smallest large igneous province. Its earliest formations are the Imnaha, Steens, and now the Picture Gorge Basalt (PGB), and they were sourced from three different dike swarms exposed from SE Washington to Nevada to northcentral Oregon. PGB is often viewed to be distinct from the other formations, as its magmas are sourced from a shallow, relatively depleted, and later subduction-induced metasomatized mantle, along with its young stratigraphic position. It has long been known that the lowermost American Bar flows (AB1&2) …

Preventing Inferences Through Data Dependencies On Sensitive Data, Primal Pappachan, Shufan Zhang, Xi He, Sharad Mehrotra

Computer Science Faculty Publications and Presentations

Simply restricting the computation to non-sensitive part of the data may lead to inferences on sensitive data through data dependencies. Inference control from data dependencies has been studied in the prior work. However, existing solutions either detect and deny queries which may lead to leakage – resulting in poor utility, or only protects against exact reconstruction of the sensitive data – resulting in poor security. In this paper, we present a novel security model called full deniability. Under this stronger security model, any information inferred about sensitive data from non-sensitive data is considered as a leakage. We describe algorithms for …

The Negative Stigma Surrounding Mathematics, Marissa A. Greisen

PSU McNair Scholars Online Journal

There is a negative stigma that surrounds mathematics in our education system. It is important to bring notice to this for the benefit of future students. There is a lot of research claiming that math is looked down on, but they do not answer why, or what we can do to fix it. Why is there a greater negative stigma around math and not other subjects? What roles to teachers, parents, and peers play in this stigma? In this article, I created a survey for people to answer questions regarding their opinion on math, who they believe typically does well …

Energy Auction With Non-Relational Persistence, Michael Ramez Howard

Dissertations and Theses

As the current landscape for electric vehicles changes, options for remote charging are expanding to keep up. In the United States alone, sales of electric vehicles grew 85% from 2020 until hitting 450,000 units by the end of 2021. While these growing sales are encouraging, commercial charging stations have a long way to go before they are as ubiquitous as gasoline stations are today. The peer-to-peer energy auction helps fill the gap in underserved areas by allowing private homeowners to share their charging facilities with other electric vehicle drivers. The auction framework wraps existing charging outlets with a Cloud-connected microcontroller. …

Tidal Bed Stress Asymmetry And Sediment Transport In Estuaries, Austin Scott Hudson

Dissertations and Theses

Rivers and estuaries provide numerous ecological, economic, and cultural resources. The value of these resources is greatly influenced by sediment transport processes, which can be affected by human activities and climate variability. A key driver of sediment transport in tidal rivers and estuaries is tidal asymmetry of velocity and bed stress, which can manifest from both non-linear tidal interactions and linear interactions among astronomical tidal constituents.

In this study, an analytical framework is developed to examine and describe the dynamics of bed stress asymmetry in semidiurnal, diurnal, and mixed-tide estuaries (Chapter 1). While tidal velocity asymmetry has been previously analyzed, …

Forest Generating Functions Of Directed Graphs, Ewan Joaquin Kummel

Dissertations and Theses

A spanning forest polynomial is a multivariate generating function whose variables are indexed over both the vertex and edge sets of a given directed graph. In this thesis, we establish a general framework to study spanning forest polynomials, associating them with a generalized Laplacian matrix and studying its properties. We introduce a novel proof of the famous matrix-tree theorem and show how this extends to a parametric generalization of the all-minors matrix-forest theorem. As an application, we derive explicit formulas for the recently introduced class of directed threshold graphs.

We prove that multivariate forest polynomials are, in general, irreducible and …

Cognitive Engagement During Group Learning Activities In Chemistry Courses: An Analysis Of Student Discourse, Safaa Youssef El-Mansy

Dissertations and Theses

As educators, our goal is to help our students be successful, but in order to accomplish this, we need to understand what factors contribute to student success. One factor, small-group active learning, has been correlated to improved academic outcomes; however, the magnitude of this improvement can vary across different courses, different types of group work, and even across courses that use the same group work structure. Therefore, it is important to understand what aspects of group work contribute to its effectiveness. The work presented in this dissertation investigated one specific aspect: students’ cognitive engagement. This was done by analyzing the …

An Overview Of Elements And Relations: Aspects Of A Scientific Metaphysics, Martin Zwick

Complex Systems Faculty Publications and Presentations

A talk on my book, Elements and Relations: Aspects of a Scientific Metaphysics. Book description:

This book develops the core proposition that systems theory is an attempt to construct an “exact and scientific metaphysics,” a system of general ideas central to science that can be expressed mathematically. Collectively, these ideas would constitute a non-reductionist “theory of everything” unlike what is being sought in physics. Inherently transdisciplinary, systems theory offers ideas and methods that are relevant to all of the sciences and also to professional fields such as systems engineering, public policy, business, and social work. To demonstrate the generality …

A Bayesian Network-Based Methodology For Improved Bridge Load Rating And Asset Management, Jeffery Mark Roberts

Dissertations and Theses

From the day a new structure is made available for use, to the day that the structure is no longer able to fulfill an intended purpose, structural safety is a vital interest. Managing a portfolio of structures can be a difficult undertaking for an asset manager, particularly if different types of structures are being maintained. The goal is to manage assets in the most efficient manner which can be influenced by, at a minimum, safety and financial concerns.

A potential tool for an asset manager or owner is the use of Bayesian Networks (BNs). When a BN is used to …

Oregon State Rank Assessment For Tui Chub (Gila Bicolor), Misty Nelson

Institute for Natural Resources Publications

Oregon state conservation status assessment for tui chub (Gila bicolor) using NatureServe methodology, 2023.

Oregon State Rank Assessment For Leopard Dace (Rhinichthys Falcatus), Misty Nelson

Institute for Natural Resources Publications

Oregon state conservation status assessment for leopard dace (Rhinichthys falcatus) using NatureServe methodology, 2023.

Faculty Senate Monthly Packet November 2023, Portland State University Faculty Senate

Faculty Senate Monthly Packets

The November 6, 2023 monthly packet includes the November agenda, appendices, and the Faculty Senate minutes and attachments from the meeting held November 6, 2023.

Evaluation Of The Slip History And Holocene Activity Of The Strawberry Fault, Grant County, Oregon, Andrew Dunning

Dissertations and Theses

Lidar topographic data for the Strawberry Mountains, Oregon has revealed youthful fault scarps that likely result from Holocene-age earthquakes. We have mapped 27 km of fault scarps striking roughly east-west across the northern foothills of the Strawberry Mountains (Strawberry Fault, SBF) and another scarp lineament striking north-south along the uppermost John Day River 10 km to the south. SBF scarps are aligned with the bedrock John Day Fault, a reactivated Miocene structure that is accommodating distributed extension north of the Basin and Range region. The Strawberry Mountains sit near the interface of the extensional Basin and Range province to the …

Evidence Of Transboundary Movement Of Chemicals From Mexico To The U.S. In Tijuana River Estuary Sediments, Flannery Mclamb, Kesten Bozinovic, Zuying Feng, Damian Shea, Miguel F. Vasquez, Chris Stransky, Richard M. Gersberg, Goran Bozinovic, Multiple Additional Authors

Center for Life in Extreme Environments Publications

The Tijuana River Estuary (TRE) has been a public health hazard and point of contention between the United States and Mexico for decades, with sources of pollution on both sides of the border. The goal of our study is to determine the presence and dynamics of chemical contamination in the TRE. We sampled sediment from four TRE locations in the U.S. during stable dry conditions and immediately after a wet weather period. Organic chemicals were initially screened with non-targeted analysis using gas chromatography high-resolution mass spectrometry (GC/HRMS) that tentatively identified 6978 chemicals in the NIST 20 database. These tentative identifications …

The Chatgpt Artificial Intelligence Chatbot: How Well Does It Answer Accounting Assessment Questions?, David A. Wood, Muskan P. Achhpilia, Mollie T. Adams, Sanaz Aghazadeh, Elizabeth D. Almer, Multiple Additional Authors

Business Faculty Publications and Presentations

ChatGPT, a language-learning model chatbot, has garnered considerable attention for its ability to respond to users’ questions. Using data from 14 countries and 186 institutions, we compare ChatGPT and student performance for 28,085 questions from accounting assessments and textbook test banks. As of January 2023, ChatGPT provides correct answers for 56.5 percent of questions and partially correct answers for an additional 9.4 percent of questions. When considering point values for questions, students significantly outperform ChatGPT with a 76.7 percent average on assessments compared to 47.5 percent for ChatGPT if no partial credit is awarded and 56.5 percent if partial credit …