Digital Commons Network^™

Varecia Rubra (Red Ruffed Lemur) Diel Activity And Calling At Andranobe, Masoala National Park, Madagascar, Hannah Elena Hilden-Reid

Dissertations and Theses

With respect to the natural variation in abiotic and biotic conditions present between daytime and nighttime periods, many animal species show evolutionary adaptations specialized for diurnality, nocturnality, or crepuscularity. Biologists have traditionally viewed categorizations of this kind as fixed within taxonomic groups, emphasizing how intricately species’ survival is contingent on the ability to adapt to low light, high light, or twilight conditions. However, movement away from such distinct temporal niche categories began within chronobiological studies following the discovery of more flexible patterns of activity in numerous taxa during the late 1970s. This shift generated increased interest in elucidating the complex …

Understanding Waveguides In Resonance, Pieter Johannes Daniel Vandenberge

Dissertations and Theses

Several important classes of modern optical waveguides, including anti-resonant reflecting and photonic bandgap fibers, make use of geometries that guide energy in low refractive index material, a property that makes them of significant interest in numerous applications, notably including high-power delivery and guidance. These waveguides frequently exhibit resonance phenomena, in which their ability to propagate an input signal is sharply curtailed at particular operating frequencies. In this work we detail new advances in understanding these resonance effects and their implications for numerical modeling of these structures.

Part 1 focuses on the fields of slab waveguides, relatively simple structures for which …

The Wage Of Wellness: The Relationship Between Socioeconomic Status, Race, And Work Recovery, Emily Julia Ready

Dissertations and Theses

A substantial share of the workforce is made up of low-income workers. Many of these workers fall below the federal poverty line and are considered low socioeconomic status (SES) and are disproportionately more likely to be racial minorities. However, this population is often neglected in the industrial-organizational psychological literature. Specifically, work recovery research has not considered the unique life circumstances of this particular group in the development of the research questions, theoretical framework, or practical implications in relation to this phenomenon. The purpose of the current study is to understand the relationship between socioeconomic status, race, and work recovery experiences …

Numerical Study Of Cone Penetration In Calcareous Sands: Investigating Cone Tip Resistance Correction Factors For Crushable Soils, Stephanie Michelle Hyder

Dissertations and Theses

The cone penetration test (CPT) is used to characterize the behavior and properties of soils, including the susceptibility to earthquake liquefaction triggering. The cone tip resistance relates to liquefaction susceptibility through relative density, where relative density is closely related to both cone tip resistance and liquefaction susceptibility. Currently, published methods of estimating liquefaction potential (i.e., cyclic resistance ratio) are based on silica sands and do not properly characterize calcareous sands. The measured cone tip resistance in calcareous sands is lower than in silica sands at the same relative density; this difference is generally attributed to the higher compressibility of calcareous …

The Relationship Between Adverse Childhood Experiences And Juvenile Offender Typology, Aliza Beth Lipman

Dissertations and Theses

Approximately 1 in 5 girls and in 20 boys in the United States are victims of child sexual assault every year. Child sexual assault can lead to multiple negative short term and long-term impacts affecting general health, mental health, interpersonal relationships, socio-economic status, criminal behavior and more. Prevention research focuses on a thorough understanding of the perpetrators of assault and the context surrounding offenses in order to reduce and prevent assault. Within this research, juvenile offenders are perceived as a single homogenous group whereas adult offenders are consistently specified based on offender and offense characteristics. The exploration of the relationship …

Corporatizing Violence: Targeted Repression Of Indigenous Dissent In Democratic States, Laikaika Layne Rivera

Dissertations and Theses

This thesis explores state repression of disruptive protests against private development projects in democracies. Using a mixed methods approach, including logistic regression and case studies, the research identifies key factors influencing repression. Indigenous leadership, fragmented public opposition, and private elite influence increase the likelihood of violent repression. The findings suggest that when public resistance is insufficient against powerful private interests, coercive institutions resort to violent strategies to quell disruptions and signal increased costs for future dissent. State repression is more likely when the protest movement is comprised of Indigenous groups than compared to those of the general public. The study …

A Survey Of North American Electric Bicycle Owners, Cameron Steven Bennett

Dissertations and Theses

Rapid recent growth in the popularity of electric bicycles (e-bikes) has captured the attention of transportation researchers and policymakers seeking safe, sustainable, and active alternatives to conventional transportation modes. This thesis presents an investigation of e-bike owners in North America, complementing previous efforts in 2013 and 2017, and suggests implications for North American transportation planning.

An online survey was distributed to e-bike owners in the United States and Canada through email outreach, purchase incentive programs, and social media. The survey included questions on the respondents’ demographics, e-bikes, purchase decisions, travel behavior, perceptions of e-bikes, crash experience, maintenance needs, and receipt …

Faculty Mentors' Influence On Latino/A/X Stem Undergraduates' Stem Identity Development, Sandy Cerda-Lezama

Dissertations and Theses

Despite Latino/a/x college student attendance rising substantially over the past decades, their graduation rates do not match the increased admission rates. In addition, Latino/a/x students are considerably under-represented in STEM. However, research suggests that when these students are encouraged by social partners to have meaningful participation and given resources such as mentoring, this eases the barriers they experience. The current study utilized interviews with 11 Latino/a/x STEM undergraduates (aged 18-29) to understand how faculty mentors influence their STEM identity development. Students shared answers about how faculty promoted and inhibited their STEM identity development through conversations about their sense of competence, …

Comparison Of Conventional And Adaptive Acoustic Beamforming Algorithms Using A Tetrahedral Microphone Array In Noisy Environments, Megan Brittany Ewers

Dissertations and Theses

In situ acoustic measurements are often plagued by interfering sound sources that occur within the measurement environment. Both adaptive and conventional beamforming algorithms, when applied to the outputs of a microphone array arranged in a tetrahedral geometry, are able to capture sound sources in desired directions and reject sound from unwanted directions. Adaptive algorithms may be able to measure a desired sound source with greater spatial precision, but require more calculations and, therefore, computational power. A conventional frequency-domain phase-shift algorithm and a modified adaptive frequency-domain Minimum Variance Distortionless Response (MVDR) algorithm were applied to simulated and recorded signals from a …

Teaching In A Kenyan Refugee Camp: A Critical Ethnography Of The Impact Of Teacher Preparation And Cultural Experience On Pedagogy, James Adiok Mayik

Dissertations and Theses

This research involved an investigation of the classroom experiences of formally unprepared refugee teachers in Kakuma Refugee camp. The purpose was to understand how refugee teachers with no preservice preparation in accordance with the standards of Kenya Teacher Service Commission (TSC) perceive and interact with pedagogical content knowledge (PCK) and cultural relevancy in their daily classroom experiences with students in a refugee camp-based school in Kenya. What informed this study was the view that refugee teachers bring with them their respective and diverse cultural knowledge--ontology, epistemology, and axiology. To gain better understanding of the experiences and perspectives of these educators, …

Understanding The Other: Mentor Ethnocultural Empathy And Relationship Quality And Duration In Youth Mentoring, Miriam Miranda-Diaz

Dissertations and Theses

Given the positive youth outcomes associated with participation in mentoring programs, there is growing interest to explore factors associated with mentoring relationship quality and duration in formal youth mentoring programs. In comparison to the majority of volunteer mentors, many young people participating in formal mentoring programs are of a racial-ethnic minority group and tend to be economically disadvantaged. This study investigates factors associated with these socio-cultural background differences between mentors and mentees. More specifically, this study investigates the association between a mentor's level of ethnocultural empathy, as reflected in empathic perspective-taking and acceptance of cultural differences, and the quality and …

Queer Rural Youth Online: A Digital Ethnography, Joseph Robert Burns

Dissertations and Theses

This thesis is based on digital ethnographic fieldwork conducted in 2023 within Queer subcommunities on the social media sites Reddit and Twitter (now known as X) and data collected from interviews with Queer rural youth members of these communities. The data reveal that social media use directly influences the lives and actions of Queer rural youth, who use the space to build social connections, shape their personal identities, and seek advice pertaining to their in-person lives and decisions. By using these spaces, Queer rural youth build both bonding and bridging social capital, learn to subvert restrictions to their Internet access, …

It Takes A Village: An Examination Of Social Relationships And Mental Health, Em Francis Trubits

Dissertations and Theses

Social relationships are impactful to mental health and well-being, both positively and negatively. Different sources of support vary in their ability to meet our needs and ultimately influence our well-being. While research has examined aspects of supportive and harmful social relationships and mental health, much of this work is cross-sectional or limited to a single source of support. This dissertation aimed to better elucidate the relationship between social relationships and mental health by integrating multiple theoretical perspectives and multiple sources of support, in a series of three empirical studies to order to inform theory and interventions targeting mental health of …

The Mirror Project: Reflections On The Experiences Of African-American Female Adolescents Experiencing Foster Care, Bahia Anise-Cross Degruy Overton

Dissertations and Theses

As the author Zora Neale Hurston says, "If you're silent about your pain, they'll kill you and say you enjoyed it." The Mirror Project (MP) aims to break this silence by giving voice to Black women who have experienced foster care in Portland, Oregon during their adolescence. In focus groups and interviews, participants shared their stories. Racial identity development theory, phenomenology and Afrocentric feminist epistemology provided lenses for gaining insight into their experiences in a predominantly white city. The MP revealed six themes: lack of youth engagement in foster care decisions, the need for a cultural lens in social work, …

Latine Dual Language Bilingual Education Teachers' Work Experiences, Nelly Noemi Patiño Cabrera

Dissertations and Theses

Given the increasing concern about the scarcity of Dual Language Bilingual Education (DLBE) teachers, it is crucial to understand the trends in teacher retention and attrition from the perspective of DLBE teachers themselves. DLBE teachers departing from their jobs imposes a significant burden on schools and students and affects the implementation of DLBE programs. To delve into this issue, this critical qualitative study focused on the work experiences of Latine K-5 Spanish/English DLBE teachers. Specifically, this study involved six participants divided into two groups of DLBE teachers in the teaching trajectory: three Latine K-5 Spanish/English DLBE teachers currently teaching in …

The Arab Spring Uprisings In Geopolitical Context, Jake Alan Rutledge

Dissertations and Theses

The question of why revolts, civil wars, and social unrest occur is central in the field of political science. This paper asks that question in the specific context of the 2011 Arab Spring uprisings as a revolutionary wave. Many theories of revolution and social unrest locate their causes in the internal characteristics of the country where they take place, such as the country's demographics or level of economic development. This paper examines the external situation of a country: its relationships with other states and the international community. This paper examines eighteen Arab countries in the Middle East and North Africa …

Mmwave Rat Optimization: Mac Layer Initial Access Design And Transport Layer Integration, Suresh Srinivasan

Dissertations and Theses

MmWave Radio Access Technology (RAT) is a promising technology for wireless communication due its large bandwidth and is already being deployed in 5G cellular and emerging WiFi technologies. MmWave systems use highly directional beams with narrow beamwidths to overcome the high path loss associated with their frequency bands. A mmWave radio can be used either in a standalone mode (where all radios use the same technology) or simultaneously with other technologies such as LTE and low frequency WiFi in a communication mode commonly referred to as integrated mode. This thesis proposes two methods to optimize mmWave RAT performance in both …

Understanding Quadrature Modulation By Designing A 7mhz Iq Test Bench To Encode The Polybius Square, William Lee Bradley

Dissertations and Theses

This thesis outlines the design of an IQ Test Bench that allows for experimentation of quadrature modulation techniques. Quadrature modulation utilizes two signals I and Q, 90° out of phase from each other, to greatly increase communication data rates. Using Desmos, a thorough mathematical analysis of waveform mixing is presented, and constellation diagrams are plotted from the results. From this an ancient fire signaling technique known as the Polybius Square is encoded into the system. The IQ Test Bench is built from fundamental components that would be contained within an RFFE: a local oscillator and two frequency mixers. The LO …

Individual And Structural Contributors To Implicit And Explicit Anti-Muslim Bias In The United States, Aeleah M. Granger

Dissertations and Theses

This dissertation consists of two manuscripts addressing the multifaceted nature of Islamophobia in the United States by examining explicit and implicit anti-Muslim bias on individual and structural levels. The first manuscript (Granger et al., 2023, see chapter II) tests an ideology-threat-attitude-behavior model by estimating the simultaneous mediating effects of threat perceptions on the relationships between individual differences in ideology, Islamophobia (fear of Muslims), and support for an anti-Muslim police surveillance policy. This study (N = 603) finds that individuals who are higher in Social Dominance Orientation (SDO), Right-wing Authoritarianism (RWA), and Nationalism are more likely to perceive Muslims as …

Sustainable Leadership During Turbulent Times, Paul Marietta

Dissertations and Theses

Teachers, administrators, and staff in schools are leaving the profession at unprecedented rates. The principal pipeline has significantly decreased in the past years and our public school system is at a breaking point. Now more than ever, we need to focus on sustainable leadership during turbulent times and helping the organization, students, families, teachers-and also their leaders-thrive. This dissertation proposal follows the Portland State University (PSU) multi-paper format which comprises a compilation of three papers in a journal article style format, with sole or multiple authors, and although PSU policy does not require it, the topic of the papers in …

Uncertainty Quantification Of Live Load Effect In Buried Rc Box Culverts, Mohd Firoj

Dissertations and Theses

Although buried and mostly invisible to the traveling public, bridge-sized culverts (i.e., culverts with span around or longer than 20 ft) account for a large proportion of state-managed bridges. As per Oregon Department of Transportation inventory, there are approximately 35,000 culverts in the state highway system. Among them, 10,862 are in poor conditions and need to be analyzed for load rating purposes. The prediction and understanding of live load effects in culverts are crucial to the design, evaluation, and life-cycle maintenance of culverts. These live load effects include maximum bending moments and shear forces at different critical cross sections.

This …

Cultivating Equity: Harnessing School Garden Education As A Catalyst For Food Justice And Social Change, Maureen Madeleine Callahan

Dissertations and Theses

In the realm of critical pedagogy, state power, and food justice in school garden education, this internship reflection paper delves into the creation and impact of a unique video project. Collaborating with a school garden education organization and a local farm owned by a pair of queer, multiracial women near Portland, Oregon, the study aimed to present K-5 students with farming and environmental insights through a food justice lens. Central inquiries explored the intersection of school garden curriculum and farming knowledge, emphasizing community-building and cultural diversity, farmer-environment interactions, engaging young students, and creating a replicable video format. Rooted in critical …

The Contested Exempla Of Lucius Cornelius Sulla, Victoria Theresa White

Dissertations and Theses

In 82 BCE, Lucius Cornelius Sulla emerged the victor of his civil war against the supporters of Marius and Cinna. The brutal aftermath of this victory, characterized by the creation of the proscriptions, would brand Sulla as a cruel and immoderate victor. Still, his successes in Rome’s previous wars against foreign enemies had enshrined Sulla as a brilliant military commander within Roman memory. Previous scholarship about Sulla has focused on the dichotomy of Sulla’s actions, often in order to evaluate his clemency or cruelty and his aims of his political reforms. This thesis analyzes how ancient Roman and Greek authors …

American Institution Of Public, K-12 Education: An Institutional Field Under A Complexity Paradigm, Jennifer Jean Joyalle

Dissertations and Theses

Institutional fields serve as foundational bedrocks that shape and govern behaviors, norms, and practices within distinct domains of societal and organizational interactions. The emergence of machine learning and the ability to manipulate large datasets offer researchers and decision makers the potential ability to model and visualize the behavior associated with institutional fields.

This proof of concept provides an example of visualizing the changing conditions in the institutional field of public K-12 education in America as a topology. By interweaving three primary strands of theory -- institutional fields, complexity in the guise of complex adaptive systems as a paradigm, and paradigms …

E Hui Me Ke Kaiāulu: To Connect With The Community, Heather Kayleen Bartlett

Dissertations and Theses

Urban planning literature contains a wealth of knowledge on community engagement as a crucial component of the planning process, yet there remains a notable gap in our understanding of best practices when it comes to sustaining community involvement for ongoing plan implementation. The County of Hawai'i, has charted a unique course through the establishment of Action Committees which serve as an intermediary to uplift grassroots implementation efforts while remaining closely entwined with County resources and processes. This interplay provides a unique case study that results in somewhat of an "identity crisis": Action Committees do not have the autonomy of external …

"Suited To The Wants Of The Country": Historical Ceramics From The Fort Vancouver Sutler's Store, Vancouver, Washington, Kaitlyn Nicole Hosken

Dissertations and Theses

For much of the early 19th century, the British Hudson's Bay Company (HBC) dominated commercial activity throughout the Pacific Northwest. Following development of the Oregon Trail in the 1840s and 1850s, however, the HBC saw increasing social and economic competition from American settlers. This research examines nationalist attitudes evident during the transition to the American colonial era and effects on the consumption of commercial goods. Analyses compare archaeological ceramics from two retail sites located in what is now Vancouver, Washington: an 1850s American sutler's store and the HBC Sale Shop. Additional comparison is made with a contemporaneous U.S. Army Officers' …

The Experiences Of Black Women Direct Care Workers In Long-Term Care, Nakeshia Knight-Coyle

Dissertations and Theses

This study expands understanding about the experiences of Black women direct care workers (DCWs) experiences with racism, discrimination, and economic exploitation in the long-term care (LTC) sector. It comes at a critical time when COVID-19 has demonstrated the important and essential nature of long-term care work. COVID-19 has also elucidated the challenges of an insufficient workforce and its detrimental impact on the long-term care system’s ability to meet the care needs of those accessing long-term care services. Finally, workforce needs are projected to increase with the impending influx of baby boomers into retirement, making this study a timely effort at …

Examining Policy Innovation Process And The Roles Of Policy Entrepreneurs: A Case Of Smart City Initiative In Khon Kaen, Thailand, Thitisak Duadsuntia

Dissertations and Theses

Innovation is a necessary process for public sector organizations and governments to adapt to social and economic changes. Innovation helps governments improve public service performance and address wicked challenges. Although the significance of public sector innovation has long been realized, how it occurs, and how it is influenced by contextual factors is not well explored. Particularly, policy innovation that emerges in an open and dynamic social system is understudied. Policy entrepreneurs mobilize policy change in their social systems, but their roles in a public sector innovation process still needs further investigation.

This study explores the policy innovation process and explicates …

How Are Oregon's Rural Indigenous Communities Overcoming Water Access Issues?, Tyren John Thompson

Dissertations and Theses

This study investigates how water insecurity affects Indigenous communities in Grand Ronde, Warm Springs, and Umatilla, Oregon, through loss of clean drinking water, access to culturally significant foods, and exposure to pollution. Each community offers innovative solutions drawing on their Indigenous knowledge to overcome water supply challenges. Communities with more resources are better equipped to cope with water insecurity and environmental degradation.

Emotion Knowledge, Its Applications, And Their Associations With African American Children's Social Relationships With Teachers And Peers In Kindergarten And First Grade, Brielle Emily Petit

Dissertations and Theses

Close and high-quality relationships with teachers and peers are a significant, positive predictor of young children's academic and social-emotional skills, whereas early conflictual relationships can pose various short- and long-term socio-emotional and academic risks. Evidence also suggests that emotion knowledge, or the ways children identify, recognize, and apply emotional labels, are a crucial factor in children's early development including overcoming social-emotional challenges and fostering high-quality interpersonal relationships. Studies examining social relationships and emotion knowledge in early childhood, however, often reveal worrisome differences in between-group comparison designs. Particularly, minoritized children, and most often Black and African American, are associated with poorer …