Digital Commons Network^™

Secondary Features Of Importance For A Url Ranking, Atajan Abdyyev

Dissertations and Theses

This paper investigates the impact of secondary ranking factors on webpage relevance and rankings in the context of Search Engine Optimization (SEO), focusing on the jewelry domain within the United States e-commerce market. By generating a keyword list related to jewelry and retrieving top URLs from Google's search results, the study employs machine learning models including XGBoost, CatBoost, and Linear Regression to identify key features influencing webpage relevance and rankings.The findings highlight specific optimal ranges for features like Outlinks, Unique Inlinks, Flesch Reading Ease Score, and others, indicating their significant impact on better rankings. Notably, Random Forest model performed best …

Examining Factors Impacting The Service Needs Of Unhoused Women, Holly Brott

Dissertations and Theses

Women account for a sizeable proportion of the unhoused population in the U.S. Over one-third (38.7%) of unhoused individuals are women, which is a 17% increase from 2016 (United States Department of Housing and Urban Development, 2019). The increased prevalence of women experiencing homelessness calls for a renewed examination of their service needs. This dissertation presents three studies examining factors impacting the service needs of unhoused women. The first manuscript examined factors contributing to unhoused mothers’ successful completion of transitional housing; highlighted participant-identified programmatic strengths; and investigated differences in facilitators to success across two geographic contexts: one rural and one …

Drivers And Dynamics Of Phytoplankton Communities And Harmful Algal Blooms In Mountain Lakes, Lara Stephanie Jansen

Dissertations and Theses

Harmful cyanobacterial blooms (cyanoHABs) are a complex and widespread disturbance in freshwater water bodies, impacting water quality for wildlife and human populations. While cyanobacteria often bloom in warm lakes impacted by human development like agriculture, blooms are increasingly reported in cooler waters with limited development in the surrounding watershed. As much of cyanoHAB research has focused on lakes in highly developed watersheds, the understanding of factors leading to cyanobacteria dominance and blooms in the absence of major development remains limited. Mountain lakes can serve as ideal systems to study bloom-forming cyanobacteria in watersheds with minimal development. In addition, mountain lakes …

Modeling Of Signals And Spectra: 5g And Beyond, Xianzhen Yang

Dissertations and Theses

The collection of papers addresses various aspects of spectra and signals in RF wireless systems for 5G and beyond. The first paper focuses on the nonlinear effects of amplified dual-band OFDM signals, providing a spectrum model for intermodulation and cross-modulation. The second paper extends this analysis beyond bandwidth restrictions, enabling accurate prediction of amplified dual-band spectrum. The third paper emphasizes the significance of out-of-band intermodulation products and derives an analytical expression using third-order intercept points. The fourth paper presents a unified spectrum expression for OFDM, FBMC, and F-OFDM, facilitating comparative insights into these signals. The fifth paper explores second-order intermodulation …

The Double Dutch Retention Framework: A Grounded Theory Study On Increasing Racial Staff Diversity At Pacific Northwest Community Colleges, Dominique S. Austin

Dissertations and Theses

This dissertation examines the troubling underrepresentation of staff of color in Pacific Northwest community colleges. Despite the proven benefits of racial staff diversity in promoting student success, community colleges face challenges in recruiting and retaining staff of color. Existing literature concerning non-teaching staff at community colleges is limited. This study adds to the existing literature by investigating the experiences and perceptions of staff of color in Pacific Northwest community colleges to identify effective strategies for increasing racial staff diversity.

This study used a constructivist grounded theory approach in a comprehensive data collection process involving surveys, individual and focus group interviews, …

Electrochemical Hydrogen Gas Production And Carbon Dioxide Sequestration Via In Situ Formation Of Nickel (Ii) Tris-(Pyridinethiolate) Derivatives, Dayalis Sv. Brown

Dissertations and Theses

In the research presented, we use electrochemical techniques, such as cyclic voltammetry and controlled potential electrolysis, to study in situ formation of hydrogen evolution catalysts which also reduce carbon dioxide. Using pyridinethiol-based ligands and a nickel (II) precursor, both homo- and heteroleptic complexes were investigated as catalysts to produce alternative fuels while mitigating greenhouse gas emissions. Existing synthetic procedures to obtain these Ni(II) catalysts lead to low yields of the complexes and difficulties in crystallizing samples for further analysis, limiting sample size and restricting the number of studies. While current research is heavily focused on photochemically-driven experiments, given that solar …

How Unequal Access To Personal And Professional Networks Impacts Success Among Construction Apprentices, Cameron Elliot Arnold

Dissertations and Theses

The construction industry is still primarily white male dominated, and while there is significant research on gendered experiences in the trades, there is not research on experiences and attitudes towards support that occurs outside of the trades across gender and other intersectional identities. My study aims to start filling the gap and answer the questions: How does access to personal and professional networks impact success among Oregon apprentices? How is access to and attitudes towards receiving support impacted by gender and race? To answer these questions this study uses qualitative interviews of Oregon apprentices who completed or terminated in 2018-2019. …

The Greeley Variations, Mary Haidri

Dissertations and Theses

Inspired by the works of Charlotte Perkins Gilman, European snake folklore, and "wished-for child" fairy tales, The Greeley Variations features several generations of women and the Victorian house they live in. The novel explores prospective parenthood, maternal legacy, and repeated patterns (visual, genetic, and psychological) as haunting experiences.

Understanding Veteran Perceptions About Mental Health And Its Treatment, Quinn Turner Stoddard

Dissertations and Theses

Mental health illnesses are a growing issue for a large part of the country, and veterans in particular are vulnerable to the numerous negative effects they pose. Despite the high number of people that may benefit from treatment, a variety of issues with trust, stigma, and attitudes may act as barriers to care utilization. In response, this study investigated the perceptions that veterans within the Pacific Northwest hold in regards to mental health treatment as well as their intentions to seek it out should they require it. Using the integrated model of behavioral prediction (IMBP), data was gathered about veterans’ …

The Impact Of Climate Change On Selected Pnw Watersheds Through The Lens Of Western Red Cedar Habitat, Jordan T. Hamann

Dissertations and Theses

Climate change is a real phenomenon that is exacerbating existing natural processes and developing into a new normal for the planet. This change may be devastating for Pacific Northwest populations of Western Red Cedar (WRC) west of the Cascade Mountain range in the states of Oregon and Washington. WRC is a valuable tree species for reasons both economic and cultural. Dieback among WRC is following an accelerating trend. Since dieback is usually followed by tree mortality, understanding its causes and distribution is beneficial to the overall success of the species going into the future.

Through the use of ESRI's ArcGIS …

Collaborative Action In Informal Social Networks Of Wildfire Managers In Northwestern Wyoming, Hannah Lynn Spencer

Dissertations and Theses

Wildfire is a cross-boundary, collective action issue. Previous research has demonstrated the importance of collaborative relationships in wildfire for purposes such as increasing capacity, trading information, and facilitating landscape-scale mitigation projects. However, a stakeholder's location in social networks, as well as personal factors, may impact their collaboration. Furthermore, stakeholders must prioritize their own organizational goals and responsibilities, which may differ from those of their collaborators. I used interview and survey methods to investigate these questions in the context of wildfire management professionals in northwestern Wyoming. For the interviews, I selected 12 individuals with high betweenness centrality who were involved in …

Confronting Web3 Technology: Opportunities, Challenges And Community Formation, Christopher-John Rogers

Dissertations and Theses

The emergence of blockchain technology created an entire industry of innovative new digital assets--or tokens--and diverse new fields of expertise founded on ideological aspirations of a new World Wide Web that reimagines digital value transfer through decentralization and disintermediation. Experimentation in the so-called "Web3" industry produces rich new fields of ethnographic study revealing the experiences of diverse individuals navigating novel technological capabilities which give way to new avenues of identity formation, community building, and ecosystem creation. These exciting new endeavors come with difficult challenges threatening the realization of ambitious visions for digital futures. Ethnographic research conducted through discourse analysis, participant …

Developing Public Service Leadership: Understanding The Field Immersion/Comparative Cases Model For Mid-Career Professional Education In Environment And Natural Resources Leadership, Erin M. Steinkruger

Dissertations and Theses

Public administrators in the United States face increasingly complex challenges and are called to leadership by position and in practice. In a hyper-pluralistic society, individuals must lead from where they sit, arbitrating value differences in day-to-day functions and taking on adversity and uncertainty in pursuit of the public good. These individuals are served by a variety of leadership training programs both internal and external to their organizations. This study characterizes the field immersion/comparative cases (FICC) model for public service leadership development and uses a grounded theory approach to build understanding about how individuals learn about leadership; what learning outcomes emerge …

Disentangling Groundwater Dynamics At Oregon's Mckenzie River Headwaters, Taylor Nicole Salazar

Dissertations and Theses

Widespread mountain snowpack declines have been occurring across the western United States over the last century, and are increasing in duration and severity, with several record-breaking low-snowpack years in the last decade. In the Pacific Northwest, summer streamflow is largely a result of melting snow and groundwater discharge, as summers are typically dry and warm in this Mediterranean bioclimate, thus making spring-fed rivers critical for regional water resources. However, current trends and predictions in hydroclimate modeling indicate spring-fed rivers will experience reduced summer discharge driven by the increasingly larger impact of anthropogenic climate change (warming) on (decreased) mountain snowpack. A …

Spatial Variations In Ancient Meteoric Water: An Investigation Of The Rattlesnake Tuff, Julian Michael Cohen

Dissertations and Theses

Volcanic glass has been used extensively as a paleoclimate proxy. Deuterium (²H) concentrations in glass have been found to be stable over geologic timescales, making δD a reliable proxy for ancient water chemistry. However, continued work revolves around better understanding how different factors affect preserved water in ash. Here, I analyze δD in the Rattlesnake Tuff (RST), a widespread ca. 7 Ma ashflow tuff, and create an isoscape to assess variations in δD across Oregon during that time. Additionally, I examine compositional data from glass shards to explore the relationship between δD and shard composition. The RST exhibits …

A Daily Investigation Of The Recovery Paradox: Examining The Dynamic Interplay Of Workload, Recovery Experiences, And Microbreaks, Morgan Rose Taylor

Dissertations and Theses

Research has highlighted the importance of recovery from work stress during non-work time for employee health and wellbeing. Building on the recovery from work stress literature, this study examines the recovery paradox which suggests that employees may recover from work demands the least when they need it the most. Therefore, the purpose of this study is to shed light on the mechanisms underlying the recovery paradox. Specifically, this study examined whether a common work stressor, workload in the morning, is indirectly related to poorer recovery experiences in the evening through negative states at the end of workday. Furthermore, this study …

Mechanisms Of Fibrillar Aggregation Of The Lens Small Heat Shock Proteins, Αa- And Αb-Crystallin, Russell James Mcfarland

Dissertations and Theses

The protein αB-crystallin represents the archetypical small heat-shock protein (sHSP), and together with αA-crystallin makes up the primary chaperone system in the eye lens, where they play a critical role in maintaining proteostasis. To achieve transparency, the lens undergoes a loss of organelles and both protein turnover halts, requiring that proteins remain functional for long periods of time as they accumulate chemical damage. The α-crystallins are highly abundant in the lens to stabilize proteostasis for multiple decades. Over time though, the small heat-shock proteins become overwhelmed by a high burden of destabilized clients and their own accumulated chemical damage. Mechanistic …

Community Supervision: Perspectives Of Probation And Parole Officers And Supervisors On Key Supervision Approaches And Policy Changes, Asianna Nelson

Dissertations and Theses

This study explores the differences across community supervision approaches in Oregon and how the implementation of state policies has influenced this field. Therefore, this study seeks to answer the following research questions: 1) How do POs and supervisors define their approach to community supervision? 2) How have POs and supervisors experienced shifts in state policy? Fourteen line staff and supervisors from seven Oregon probation and parole agencies were interviewed to answer these research questions. The findings suggest that most agencies are using evidence-based practices and implementing state policies. However, variation exists across the represented agencies in the experiences and perceptions …

Systematic Characterization Of Power Side Channel Attacks For Residual And Added Vulnerabilities, Aurelien Tchoupou Mozipo

Dissertations and Theses

Power Side Channel Attacks have continued to be a major threat to cryptographic devices. Hence, it will be useful for designers of cryptographic systems to systematically identify which type of power Side Channel Attacks their designs remain vulnerable to after implementation. It’s also useful to determine which additional vulnerabilities they have exposed their devices to, after the implementation of a countermeasure or a feature. The goal of this research is to develop a characterization of power side channel attacks on different encryption algorithms' implementations to create metrics and methods to evaluate their residual vulnerabilities and added vulnerabilities. This research studies …

Who Puts The "Support" In Supportive Housing? The Impact Of Housing Staff On Resident's Well-Being, And The Potential Moderating Role Of Self-Determination, Kenna Estell Dickard

Dissertations and Theses

The provision of residential and community-based services for individuals with serious mental illness (SMI) has become increasingly important following the deinstitutionalization movement. Much of the existing research on supportive housing focuses on housing outcomes rather than exploring how the program helps its residents thrive in the broader community. This study draws upon data collected from 176 people with SMI residing in 16 supportive housing locations in Portland, Oregon. Analyses employed an ecological approach, exploring how housing staff support relates to residents' well-being at three levels of analysis: loneliness (interpersonal level), residential satisfaction (housing and neighborhood level), and sense of community …

Developing And Testing Low-Cost Air Cleaners For Safer Spaces During Wildfires, Brett William Stinson

Dissertations and Theses

Air cleaning reduces indoor exposure to fine particulate matter (PM_2.5) during wildfire events. However, resource and cost restraints may limit access to air cleaning during such an event, as both commercial devices and the high-rated MERV filters that homemade assemblies typically rely upon tend to be expensive and in short supply. With these barriers in mind, we sought to develop and evaluate the potential for air cleaners that use common household fabrics as filtration media. Evaluated designs use a box fan to move air across fabric filters; box fans are inexpensive and readily available to many households. Ultimately, …

Understanding Influenza Vaccine Hesitancy And Uptake Among U.S. Hispanic Adults During The Covid-19 Pandemic, Helen J. Arteaga

Dissertations and Theses

The health burden caused by seasonal flu is substantial in the general population and each season targeted efforts are needed to decrease the risk of flu illness, hospitalization, and death. Flu risks and the disease burden are disproportionately higher among Hispanic adults, yet little is known about the factors influencing flu vaccine hesitancy and uptake among this marginalized population. This cross-sectional quantitative study used national survey data from the Understanding America Study (UAS) and logistic regression to address three research aims. Aim 1 was to examine the most significant demographic factors associated with flu vaccine uptake among the Hispanic community. …

A Deep Hierarchical Variational Autoencoder For World Models In Complex Reinforcement Learning Environments, Sriharshitha Ayyalasomayajula

Dissertations and Theses

Model-based reinforcement learning (MBRL) approaches leverage learned models of the environment to plan and make optimal decisions, reducing the need for extensive real-world interactions and enabling more efficient learning in complex domains such as robotics, autonomous systems, and resource allocation problems. They also provide interpretability and insight into the underlying dynamics, facilitating better decision-making and system understanding.

The world model is a model-based RL approach that employs generative neural network models to learn a compressed spatial and temporal representation of the environment. This work explores world models and a simple single-layered RNN model to learn a simple policy based on …

Son Otros Tiempos: Generational Experiences Of Male Friendships Amongst Mexican And Mexican American Men, Marisela Rodríguez Molina

Dissertations and Theses

Culturally specific work with Latinx men has also discussed the way Latinx masculinities are being redefined by younger generations. Grounded in Chicana Feminist epistemologies, I use Gloria Anzaldua's borderlands framework to analyze data from 20 interviews with sons and their father figures in understanding experience of masculinities within the context of male friendships. Differences between father's and son's experiences can be attributed to social context in which men are socialized and their borderlands experiences. Findings illustrate how understandings of masculinities represent a melding of cultural values between the dominant individualistic perspective in the U.S. and the collectivist perspective from men's …

Improving Peer-To-Peer Learning For Students With Extensive Support Needs In Inclusive Classrooms, Zachary Michael Deets

Dissertations and Theses

Inclusive learning opportunities lead to better outcomes for students with extensive support needs (ESN). In the absence of targeted intervention, however, students with ESN are unlikely to interact meaningfully with their peers or the general education curriculum. The literature describes evidence-based strategies in support of the meaningful inclusion of students with ESN in inclusive classrooms, including the use of technology to mediate learning experiences and nondisabled peers as learning "interventionists." This dissertation introduces an intervention package, Technology-Assisted Peer-Mediated Academic Support (TAPMAS), incorporating Technology-Aided Instruction and Intervention (TAII) and Peer-Based Instruction and Intervention (PBII), as a model of how educators may …

An Integrated Analysis Of Urban Sustainability In Portland: Issues, Indicators, Stakeholders, And Geospatial Assessment, Arun Kumar Pallathadka

Dissertations and Theses

This dissertation presents three individual studies that collectively explore the concept of urban sustainability. The research is grounded in the recognition that many cities worldwide are striving to achieve sustainable development, yet existing sustainability frameworks often lack comprehensive definition and consideration. Moreover, the existing sustainability frameworks and methods are often not clearly structured to allow for their replication and adaptation to meet the unique needs of diverse local settings. To address this gap, the dissertation utilizes the Social-Ecological-Technological Framework, with particular emphasis on equity, to investigate key issues in urban sustainability, such as indicators, stakeholder engagement, tradeoffs, and assessment. The …

Creating Regression Model For Non-Markov Transition Probability Using Pseudo-Observations, Michael Gray

Dissertations and Theses

A multi-state model is a graphical tool widely used to illustrate a transitional relationship between states in many applications. We will study the transition probabilities of an illness-death model, which is an example of a multi-state model. We will investigate transition probabilities using a counting process approach. Aalen-Johansen estimator is the gold-standard in estimating a transition probability. However, Aalen-Johansen estimator may be biased when the Markov assumption is violated. Therefore, Aalen-Johansen estimator is an unreliable estimator when the Markov assumption is violated. Several papers have published non-parametric estimators that accommodate for non-Markov models using a counting process approach.

Furthermore, there …

Survival Times And Investment Analysis With Dynamic Learning, Zhenzhen Li

Dissertations and Theses

The central statistical problem of survival analysis is to determine and characterize the conditional distribution of a survival time given a history of some observed health markers.

This dissertation contributes to the modeling of such conditional distributions in a setup where the health markers evolve randomly over time in a manner that can be represented by an Ito stochastic process, that is, a stochastic process that can be written as a sum of a time integral of some stochastic process and an Ito integral of some stochastic process, with both integrands subject to certain restrictions.

The random survival time is …

The Health Impacts Of The Trump Administration Among California Immigrants, Claudia M. Calhoon

Dissertations and Theses

Immigration policy was a marquee issue in the US presidential administration of Donald Trump. Trump’s administration employed both policy and rhetoric related to immigrants to mobilize voters, alter immigration policies and practices, and sustain a narrative of a nation under attack by immigrants. Administration officials were able to undertake these approaches because of existing immigration law, but they did so in more explicitly punitive ways than in recent administrations. The goal of this dissertation is to explore the health impacts of the administration’s practices and their effects. Paper 1 analyzes the immigration rhetoric and policies of US president Donald Trump …

A Policy Proposal For Agricultural Data Governance, Ana Sofía Castellanos Santamaría

Dissertations and Theses

As the digital economy continues to grow and data becomes increasingly important, effective data governance is essential. A data governance framework enables the efficient management, sharing, and integration of data, resulting in better decision-making, increased productivity, and enhanced innovation across industries, including agriculture. However, the agricultural sector in the United States is lagging behind other industries in the adoption of effective data governance practices. Agricultural data governance presents a unique set of challenges due to the wide range of stakeholders involved and the ever-increasing volume of data generated by digital technologies in farming. One key challenge to achieving the benefits …