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The Geologic History Of The Chehalis Forearc Basin, Washington State, Usa, Rud Lamb Moe

Dissertations and Theses

The Chehalis Basin, in southwest Washington, is one of a series of forearc basins between the Cascade Arc and the Coast Range in the Pacific Northwest. While the Seattle basin to the north, and the Portland-Tualatin basins to the south are both relatively well studied, the geologic evolution of basins in between is poorly constrained. The Chehalis basin is underlain by accreted Eocene oceanic basalt of the Crescent Formation. The basin fill consists of sedimentary rocks and volcanic rocks deposited throughout the Cenozoic. It has undergone N-S shortening driven by transpressional stress from oblique subduction of the Juan de Fuca …

Estimated Amounts Of Terrestrial Carbon Mobilized And Sequestered By The 1980 Mount St. Helens Eruption, Washington State, Usa, Lizzet G. Reyes

Dissertations and Theses

Volcanic eruptions significantly influence the geologic carbon cycle by emitting CO₂ and mobilizing terrestrial carbon pools. The 1980 Mount St. Helens (MSH) eruption offers a unique case study, triggering a massive landslide that displaced 2.7 km³ of sediment, buried 600 km² of forest, and disrupted regional carbon dynamics. Pre-eruption terrestrial carbon stocks, including aboveground biomass (AGB), dead biomass (D), and soil organic carbon (S), averaged 209.5 tC/ha. Post-eruption, total carbon density fell to 118.7 tC/ha, driven mainly by a 51% reduction in AGB, modest declines in D, and redistribution of S. Over 36 years, ecosystem recovery increased …

Development Scenarios And Wildfire Risk In Central Oregon, Samantha Hall

Dissertations and Theses

Risk from natural hazards occurs where areas vulnerable to natural hazards and development intersect. Development in vulnerable areas is a societal choice that has a lasting impact as our built environment is relatively permanent. Development patterns that contribute to increased wildfire risk mostly occur within the wildland urban interface, a land use type where development is at the fringes or intercept of wildland areas and is more flammable due to surrounding vegetation, slope, local climate, and other factors. To understand how past and future development potentials may impact fire risk in wildfire prone areas, a case study of Deschutes County, …

Enhancing Frequency Event Detection In Power Systems Using Two Optimization Methods With Variable Weighted Metrics, Hussain A. Alghamdi, Midrar A. Adham, Umar Farooq, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

This research presents a novel technique that refines the performance of a frequency event detection algorithm with four adjustable parameters based on signal processing and statistical methods. The algorithm parameters were optimized using two well-established optimization techniques: Grey Wolf Optimization and Particle Swarm Optimization. Unlike conventional approaches that apply equally weighted metrics within the objective function, this work implements variable weighted metrics that prioritize specificity, thereby strengthening detection accuracy by minimizing false-positive events. Realistic small- and large-scale frequency datasets were processed and analyzed, incorporating various events, quasi-events, and non-events obtained from a phasor measurement unit in the Western Interconnection. An …

Perceptions About Potential Microplastic Interventions: A Study On Knowledge, Concerns, And Willingness To Pay, Amanda Gannon, Elise F. Granek, Max Nielsen-Pincus, Luke Harkins

Environmental Science and Management Faculty Publications and Presentations

Among emerging contaminants, microplastics (MPs) are of particular concern due to their ubiquity across environments and the unique challenges posed by attempted removal. In-line washing machine filters are one potential tool for preemptively preventing a category of MPs from entering waterways. A sample of registered voters and environmental interest groups in Oregon were asked about their general knowledge and concerns surrounding microplastics, as well as their willingness to pay for high-efficiency washing machine filters. Findings show that less than a quarter of all respondents would be willing to pay full price for a high-efficiency filter, indicating a limited-scale early adopter …

An Effective Genetic Algorithm For Mixed Precision, Wanyu Zhang, Yu Shang, Min Tsao, Yiwei Li, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

The precision of floating-point numbers is a critical task in high-performance computing. Many scientific applications rely on floating-point arithmetic, but excessive precision can lead to unnecessary computational overhead. Reducing precision may introduce unacceptable errors. Addressing this trade-off is essential for optimizing performance while ensuring numerical accuracy. In this paper, we present a genetic algorithm-based approach for tuning the precision of floating-point computations. Our method leverages algorithmic differentiation and first-order Taylor series approximation to assess the impact of precision variations efficiently. We employ stochastic partitioning algorithms with multiple precision combinations that meet the error requirements. Moreover, we present a genetic heuristic …

Manifesto Of An Arab Female, Diditta Rizk

Amplify: A Journal of Writing-as-Activism

In this manifesto, the author provides a window into her gendered experiences growing up female in the Middle East. In identifying the ways that women encounter obstacles to expressing their full agency in male-dominated societies, the author invites the reader to join her in redefining the narrative of what it is and means to be a woman. The manifesto ends with a call for us to become architects of a new perspective through which equity becomes reality, one where we strive collectively for peace, freedom, and the pursuit of the common good.

Investigating Key Structures In Protective Scenes For Llms, Eben M. Weisman

University Honors Theses

This research delves into the realm of "protective scenes" within Large Language Models (LLMs), exploring their impact on bias mitigation, deception, and context preservation. The study investigates the use of roleplay prompting human-like behavior and reasoning in LLMs, focusing on the Character-LLM framework's concept of protective scenes with graduated levels of protection. By combining insights from psychology, cognitive science, and computational analysis, this research aims to develop a framework for understanding how protective scenes influence roleplay performance in LLMs, ultimately contributing to the development of more reliable and ethical AI systems.

Abiotic Variables Drive Different Aspects Of Fish Community Trait Variation And Species Richness Across The Continental United States, Alicia Mcgrew, Crysta Gantz, Brigid Wills, Benjamin Baiser, Sydne Record, Phoebe L. Zarnetske, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Intraspecific trait variation (ITV) is an increasingly important aspect of biodiversity and can provide a more complete perspective on how abiotic and biotic processes affect individuals, species' niches and ultimately community-level structure than traditional uses of trait means. Body size serves as a proxy for a suite of traits that govern species' niches. Distributions of co-occurring species body sizes can inform niche overlap, relate to species richness and uncover mechanistic drivers of diversity. We leveraged individual-level body size (length) in freshwater fishes and environmental data from the National Ecological Observatory Network (NEON) for 17 lakes and streams in the contiguous …

Adaptive Resolution Of Fine Scales In Modes Of Microstructured Optical Fibers, Jay Gopalakrishnan, Jacob Grosek, Gabriel Pinochet-Soto, Pieter Vandenberge

Mathematics and Statistics Faculty Publications and Presentations

An adaptive algorithm for computing eigenmodes and propagation constants of optical fibers is proposed. The algorithm is built using a dual-weighted residual error estimator. The residuals are based on the eigensystem for leaky hybrid modes obtained from Maxwell equations truncated to a finite domain after a transformation by a perfectly matched layer. The adaptive algorithm is then applied to compute practically interesting modes for multiple fiber microstructures. Emerging microstructured optical fibers are characterized by complex geometrical features in their transverse cross section. Their leaky modes, useful for confining and propagating light in their cores, often exhibit fine-scale features. The adaptive …

Working Paper No. 88, Algorithms And Thorstein Veblen’S ‘Machine Process’, Eunji Jang

Working Papers in Economics

This inquiry seeks to establish that the ‘machine process’ which Thorstein Veblen introduced into the Economics literature back in 1904, exhibits similarities to algorithms that are readily found in contemporary times--more than one hundred years on. In The Theory of Business Enterprise [1904] (2005), Veblen defines the machine process as a system that prioritizes efficiency, standardization, and automation. Relatedly, this inquiry argues that algorithms are based upon similar principles and exhibit similar tendencies that yield similar outcomes. Additionally, this inquiry explores the institutional role of algorithms, elaborating upon how their increasing prevalence and solidification might serve to enhance efficiency in …

Near Convexity And Generalized Differentiation, Nguyen Mau Nam, Nguyen Nang Thieu, Nguyen Dong Yen

Mathematics and Statistics Faculty Publications and Presentations

In this paper, we introduce the concept of nearly convex set-valued mappings and investigate fundamental properties of these mappings. Additionally, we establish a geometric approach for generalized differentiation of nearly convex set-valued mappings and nearly convex functions. Our contributions expand the current knowledge of nearly convex sets and functions, while providing several new results pertaining to nearly convex set-valued mappings.

“Tikkun” Viewed From The Perspective Of Systems Philosophy, Martin Zwick

Complex Systems Faculty Publications and Presentations

Understanding the idea of tikkun, as it appears in tikkun olam and tikkun ha’yetser, can be enriched by ideas from systems philosophy. From a systems perspective, “moral evil“ – the flaws of individual human beings, which create the need for tikkun ha’yetser – is a special case of “natural evil” – the dangers to life and especially to humanity from the natural world and from societal moral evil, which create the need for tikkun olam. Natural evil is in turn a special case of “metaphysical evil” – flaws in olam (which include those of yetser) that are ubiquitous, …

Accessible Bike Map Design: A Review And Critique Of Portland’S Bike Maps, Zachary Cheyney

Geography Masters Research Papers

Urban bike maps can serve as key tools for route planning and navigation for prospective cyclists, providing both general information (such as landmarks and natural features) and cycling specific information (such as bike lane infrastructure types and cycling amenities). Despite this, there is little professional guidance or academic research on best practices for bike map design. Potential guidance should consider the full range of potential cyclists, including disabled cyclists who have often been left out of cycling policy discussions. In this paper, I begin by discussing 3 case studies on participatory mapping methodologies with disabled participants in order to generate …

Indigenous Futures: Decolonizing Conservation And Restoring Ecological Sovereignty, Jasmine Beach

University Honors Theses

This study examines how members of Indigenous-led conservation organizations perceive the ecological and social implications of colonial conservation ideologies in the context of contemporary grassroots strategies. By analyzing the ongoing impact of conservation frameworks in Kenya, this research highlights the role of Indigenous-led initiatives in advancing sustainable, community-driven alternatives. Using a Two-Eyed Seeing approach, which integrates Traditional Ecological Knowledge (TEK) with Western scientific methods, the study employs qualitative, semi-structured interviews with leaders from Zawadisha, KENVO, Wildlife Works, and CER-Kenya. Findings indicate that these organizations, particularly those led by women, actively restore biodiversity, enhance climate resilience, and challenge exclusionary conservation policies. …

Characterizing Rainfall Variability Within A Series Of Storms Over Northern California In February 2017, Parker Jan Malek

Dissertations and Theses

In February 2017, a series of storms with associated atmospheric rivers (ARs) made landfall in the US state of California, dropping large amounts of precipitation over the Sierra Nevada Mountains and their western foothills. The rainfall from these ARs, long, narrow bands of water vapor that transport large amounts of water vapor from the tropics to the mid-latitudes, instigated the near-failure of the Oroville Dam located at the southeastern edge of the Feather watershed outside the city of Oroville in the state's Central Valley. This case study provides a synoptic and mesoscale diagnosis of the drivers of rainfall pulses that …

Next Arrival And Destination Prediction Via Spatiotemporal Embedding With Urban Geography And Human Mobility Data, Pengjiang Li, Zaitian Wang, Xinhao Zhang, Pengfei Wang, Kunpeng Liu

Computer Science Faculty Publications and Presentations

With the development of transportation networks, countless trajectory data are accumulated, and understanding human mobility from traffic data could be helpful for smart cities, urban computing, and urban planning. Extracting valuable insights from traffic data, such as taxi trajectories, can significantly improve residents’ daily lives. There are many studies on spatiotemporal data mining. As we know, arrival prediction or regional function detection encompasses important tasks for traffic management and urban planning. However, trajectory data are often mutilated because of personal privacy and hardware limitations, i.e., we usually can only obtain partial trajectory information. In this paper, we develop an embedding …

Extant Life Detection Using Label-Free Video Microscopy In Analog Aquatic Environments, Carl D. Snyder, Manuel Bedrossian, Casey Barr, Jody W. Deming, Chris A. Lindensmith, Christian Stenner, Jay L. Nadeau

Physics Faculty Publications and Presentations

The ability of microbial active motion, morphology, and optical properties to serve as biosignatures was investigated by in situ video microscopy in a wide range of extreme field sites where such imaging had not been performed previously. These sites allowed for sampling seawater, sea ice brines, cryopeg brines, hypersaline pools and seeps, hyperalkaline springs, and glaciovolcanic cave ice. In all samples except the cryopeg brine, active motion was observed without any sample treatment. Active motion was observed in the cryopeg brines when samples were subjected to a temperature gradient above in situ. In general, levels of motility were low in …

Pdxscholar Multi-Year Annual Report (2022-2024), Julia Stone, Sherry Buchanan, Bertrand Robinson, Stacey Schlatter, Carolee Harrison

Library Faculty and Staff Publications and Presentations

We are excited to share our 2022-2024 PDXScholar Multi-Year Annual Report. This multi-year report covers the period between January 1, 2022 and December 31, 2024. PDXScholar, Portland State University's institutional repository, provides access to the scholarly and creative output of PSU faculty, students, and staff. In this report, we aim to highlight PDXScholar’s growth and impact through readership data, new content and collections, and feedback from our users.

Realizing Intrinsically Ultralow And Glass-Like Thermal Transport Via Chemical Bonding Engineering, Zhonghao Xia, Xingchen Shen, Jun Zhou, Yuling Huang, Yali Yang, Jiangang He, Yi Xia

Mechanical and Materials Engineering Faculty Publications and Presentations

Crystals exhibiting glass-like and low lattice thermal conductivity ( ) are not only scientifically intriguing but also practically valuable in various applications, including thermal barrier coatings, thermoelectric energy conversion, and thermal management. However, such unusual are typically observed only in compounds containing heavy elements, with large unit cells, or at high temperatures. In this study, chemical bonding principles are utilized to weaken the Ag–Ag bonds and enhance lattice anharmonicity. The incorporation of a chalcogen anion as a bridge ligand is proposed to facilitate phonon rattling in Ag6-octahedron-based compounds. Guided by this design strategy, five Ag6 octahedron-based compounds, AAg3X2 (A = …

Layout-Aware Quantum Circuitry And Algorithmic Extensions To Grover's Algorithm, Ali Al-Bayaty

Dissertations and Theses

Lov K. Grover introduced, in 1996, Grover's algorithm as a quantum search algorithm to find all solutions for quantum oracles representing classical problems. My research observed that the Grover diffusion operator of Grover's algorithm gives wrong solutions when Boolean oracles are designed in some logical structures. Therefore, I invented the new "controlled-diffusion operator" for Boolean oracles as a new approach for Grover's algorithm that always correctly solves the problem of Grover's algorithm.

Another important problem in quantum computing is designing reliable and cost-effective quantum gates using reversible binary logic. In classical logic design, the stage of logic design can be …

Model Explanations For Gender And Ethnicity Bias Mitigation In Ai-Generated Narratives, Martha Otisi Dimgba

Dissertations and Theses

Large Language Models (LLMs) are increasingly utilized in diverse applications, ranging from professional content creation to decision-making systems. However, their outputs often amplify the biases present in their training data, perpetuating stereotypes and reinforcing societal inequities, particularly regarding gender and ethnicity. Such biases can cause tangible harm, especially for underrepresented groups, and require awareness and effective mitigation strategies.

This work explores gender and ethnicity representation in narratives created by generative AI describing 25 occupational fields defined by the U.S. Bureau of Labor Statistics. We examine three large language models (LLMs)--Llama 3.1 70B Instruct, Claude 3.5 Sonnet, and GPT 4.0 Turbo. …

The Role Of Homocysteine Redox Chemistry In Biomolecular Mechanisms, Megha Gupta

Dissertations and Theses

Homocysteine at elevated levels is a well-known independent risk factor for cardiovascular disease. However, it is still unclear, after large scale clinical trials, involving tens of thousands of patients, whether homocysteine is a disease mediator or marker. The disconnect between the basic science showing the association of homocysteine with cardiovascular disease and the outcomes of clinical trials based on vitamin therapy for homocysteine lowering, highlights the need for insights into the molecular mechanisms linking homocysteine to cardiovascular disease and other pathologies. For example, elevated homocysteine levels have also been associated with risk for stroke, venous thromboembolism, Alzheimer's disease, neural tube …

Lagging Brain Gene Expression Patterns Of Drosophila Melanogaster Young Adult Males Confound Comparisons Between Sexes, Flannery Mclamb, Zuying Feng, Jeanne P. Vu, Lindsey Griffin, Miguel F. Vasquez, Goran Bozinovic

Center for Life in Extreme Environments Publications

Many species, including fruit flies (Drosophila melanogaster), are sexually dimorphic. Phenotypic variation in morphology, physiology, and behavior can affect development, reproduction, health, and aging. Therefore, designating sex as a variable and sex-blocking should be considered when designing experiments. The brain regulates phenotypes throughout the lifespan by balancing survival and reproduction, and sex-specific development at each life stage is likely. Changes in morphology and physiology are governed by differential gene expression, a quantifiable molecular marker for age- and sex-specific variations. We assessed the fruit fly brain transcriptome at three adult ages for gene expression signatures of sex, age, and sex-by-age: 6698 …

Advances In Theory And Computational Methods For Next-Generation Thermoelectric Materials, Junsoo Park, Alex M. Ganose, Yi Xia

Mechanical and Materials Engineering Faculty Publications and Presentations

This is a review of theoretical and methodological development over the past decade pertaining to computational characterization of thermoelectric materials from first principles. Primary focus is on electronic and thermal transport in solids. Particular attention is given to the relationships between the various methods in terms of the theoretical hierarchy as well as the tradeoff of physical accuracy and computational efficiency of each. Further covered are up-and-coming methods for modeling defect formation and dopability, keys to realizing a material's thermoelectric potential. We present and discuss all these methods in close connection with parallel developments in high-throughput infrastructure and code implementation …

Impact Of Roughness Spanwise Wavelength On Secondary Flow Rearrangement, Jianzhi Yang, Xiang I. A. Yang, Luoqin Liu, Jian Zhu, Xiaowei Zhu

Mechanical and Materials Engineering Faculty Publications and Presentations

Spanwise heterogeneity in surface roughness generates secondary mean flows in a rough-wall turbulent boundary layer. This study investigates the influence of roughness spanwise wavelength on the arrangement of these secondary flows using direct numerical simulation (DNS). We systematically vary the spanwise wavelength, δS/δ⁠, from ππ/16 to π2π⁠, while maintaining constant roughness height and surface coverage density. Here, S represents the roughness spanwise wavelength, and δδ denotes the outer length scale, which in this case is the half-channel height. Secondary flows are observed in all DNS cases, but their configurations depend on the spanwise wavelength. Specifically, small wavelengths result in low-momentum …

Plural Water Narratives: An Environmental Justice Lens On A Systematic Review Of Q-Methodology Water Research, Melissa Haeffner, Alida Cantor, Janet Cowal, Andrea Bryant, Darius Mani Yaw, Kinna Je Palacios, Daniela Serna, Bryce Sprauer, Abigail Tran-Gruver

Environmental Science and Management Faculty Publications and Presentations

Environmental justice research has shown that people's experiences and perceptions of water differ because systematic inequalities shape the extent to which people access clean water and are exposed to water hazards. Q‐methodology is one technique that has been used to aggregate multifaceted subjective narratives and understand different perspectives on a topic. In this paper, we systematically review 77 case study articles applying Q‐methodology to water‐related topics, to inventory how people perceive their relationships with water. We create a classification system based on environmental justice theory to examine (1) distributive justice issues around alternative water sources and agricultural and urban water …

Quantum Finite Automaton Using Ternary Rotation Quantum Gates And Chrestenson Family Quantum Gates, Yuchen Huang, Marek Perkowski, Xiaoyu Song, John M. Acken

Electrical and Computer Engineering Faculty Publications and Presentations

Quantum automata can solve certain problems with a smaller state space than classical automata. We developed a quantum finite automaton using ternary rotation quantum gates and the Chrestenson family of ternary quantum gates. The main idea of this paper is to show how to combine rotation ternary quantum circuit-based QuantumFinite Automaton and quantum reversible circuit-based Deterministic Finite Automaton to build a more powerful machine. The combined machine can enable more complex language and pattern recognition. The developed quantum finite automaton and resulting combined machine can be used for robotics applications such as language, gesture, and motion recognition.

The Effects Of Imidacloprid And Polyester Microfibers On The Larval Development Of The Endangered Sunflower Star, Alexandra G. Tissot, Elise F. Granek, Fiona Curliss, Augustin Kalytiak-Davis, Jason Hodin, Michelle L. Hladik

Environmental Science and Management Faculty Publications and Presentations

Sea star wasting syndrome has affected numerous species of sea star, with populations of Pycnopodia helianthoides (Brandt, 1835) left most at risk. As their populations are struggling to recover, it is important to gain a better understanding of the impacts that the multiple stressors in their habitats can have on their populations. Contaminant stressors in particular are of increasing importance, because aquatic organisms can be exposed to a dynamic range of contaminants from nearby anthropogenic activity that may affect their future recovery efforts. This study is the first to quantify the effects of contaminant stressors on the larvae of P. …

Investigating Environmental Controls On Temperature Dynamics In An Urban Stream, Matthew Cullen Yates

Dissertations and Theses

Water temperature is a critical environmental variable influencing aquatic ecosystems. This study investigated the factors controlling stream temperature and thermal stratification in Rock Creek (RC) and Bethany Lake, an urbanized watershed featuring an in-line irrigation pond and buried wastewater infrastructure. Previous research suggested that subsurface water flow might drive temperature shifts in Rock Creek during summer periods when flow from Bethany Lake ceases. From 2023 to 2024, continuous temperature and stage monitoring, combined with statistical methods including principal component analysis and random forest regression, were used to evaluate seasonal temperature dynamics and their controlling factors. Results confirmed that seasonal reversals …