Digital Commons Network^™

Relationship Between Anisotropy And Dispersive Stress In Wind Plants With Variable Spacing, Tamara S. Dib

Dissertations and Theses

Large eddy simulations are considered for wind plants with varied spanwise and streamwise spacing. Data from five different configurations of staggered and aligned LES wind turbine arrays with a neutrally stratified atmospheric boundary layer are employed for analysis. Fields are analyzed by evaluating the anisotropy stress invariants based on the Reynolds shear stresses and dispersive stress tensor. The relationship between quantities are drawn as a function of the wind plant packing. Reynolds stresses and dispersive stresses are investigated alongside a domain altered version of the second and third scalar invariants, ξ, η, as well as the combination of the …

Recovery Of Zooplankton Communities To Whole-Lake Disturbance, Brian Newton Mcgann

Dissertations and Theses

Community assembly following disturbance is a key process in determining the composition and function of the future community. However, replicated studies of community assembly at whole ecosystem scales are rare. Here is described a series of whole-lake experiments in which the recovery of zooplankton communities is tracked following an ecosystem-scale disturbance. Fourteen lakes in eastern Washington were chosen: seven lakes were treated with rotenone, while the remaining seven were reference. Each lake was monitored up to six months before and one to two years after the rotenone treatments. Zooplankton tows were taken monthly, at a shallow, intermediate, and deep site …

Framing Race And Blame In The Media: A Case Study On The Chapel Hill Shooting, Sara Abdullatif Galadari

Dissertations and Theses

This research examines how racism is hidden and denied by the press, and how blame is attributed to individuals in crime news stories. This research heavily relies of van Dijk's (2015) six discursive strategies to reveal how racism is hidden and denied in the press: positive self-presentation, denial and counter-attack, moral blackmail, subtle denials, mitigation, and defense and offense. Specifically, the Chapel Hill shooting is used as an example of a crime news story for my case study. This study will use framing as the primary method, and critical discourse analysis will be used to guide my interpretations of the …

Foreign Language Anxiety, Sexuality, And Gender: Lived Experiences Of Four Lgbtq+ Students, James Donald Mitchell

Dissertations and Theses

The relationship between foreign language anxiety and gender identity has been largely a quantitative endeavor that has shown contradictory results. Furthermore, sexual identity has not been researched in foreign language anxiety literature. A qualitative account of LGBTQ+ language learners with different gender identities has been absent from the literature. Therefore, the purpose of this study was to explore the relationship between foreign language anxiety and sexual and gender identity. To gain insight into this relationship, this qualitative study investigated the lived experiences of four LGBTQ+ foreign language university students who represented three gender identities. Data were collected through multiple, in-depth …

The Antecedents Of Local Government Service Delivery Under Crisis Conditions: The Case Of Khon Kaen Province, Thailand, Sirisak Laochankham

Dissertations and Theses

The aim of this research is to understand local service delivery in Thailand's post-2006 national political crisis. The researcher collected qualitative data in four municipalities in Khon Kaen Province. The analytical framework covered five moderating variables: political institutions, civic engagement, political leadership, governance, and political economy. The results were mixed. Local service delivery suffered from weakening electoral mechanisms, suspended local autonomy, weakened civic participation and policy networks, insecure local administrators, worsened central-local trust, and the detrimental effect on local economies. However, there were opportunities for improved, or maintained, local service delivery through the lessening of administrative procedures, a fast-track mechanism …

Glacier Inventories And Change In Glacier National Park, Melissa Carrie Brett

Dissertations and Theses

Glacier National Park, in northwestern Montana, is a unique and awe-inspiring national treasure that is often used by the media and public-at-large as a window into the effects of climate change. An updated inventory of glaciers and perennial snowfields (G&PS) in the Park, along with an assessment of their change over time, is essential to understanding the role that glaciers are playing in the environment of this Park. Nine inventories between 1966 and 2015 were compiled to assess area changes of G&PS. Over that 49-year period, total area changed by nearly -34 ± 11% between 1966 and 2015. Volume change, …

Development Of A Liquid Contacting Method For Investigating Photovoltaic Properties Of Pbs Quantum Dot Solids, Vitalii Alekseevich Dereviankin

Dissertations and Theses

Photovoltaic (PV) devices based on PbS quantum dot (QD) solids demonstrate high photon-to-electron conversion yields. However, record power conversion efficiencies remain limited mainly due to bulk and interfacial defects in the light absorbing material (QD solids). Interfacial defects can be formed when a semiconductor, such as QD solid, is contacted by another material and may predetermine the semiconductor/metal or semiconductor/metal-oxide junction properties. The objective of the work described in this dissertation was set to explore whether electrochemical contacting using liquid electrolytes can provide sufficient means of contacting the QD solids to investigate their PV performance without introducing the unwanted interfacial …

College Student Rankings Of Multiple Speakers In A Public Speaking Context: A Language Attitudes Study On Japanese-Accented English With A World Englishes Perspective, John James Ahlbrecht

Dissertations and Theses

This language attitudes study used a matched guise technique to compare participant reactions of American-accented English to Japanese-accented English. Participants (n = 40) were college educated adults living in the Portland area who completed an online survey which measured characteristics related to Status, Solidarity, and Dynamism using semantic differential Likert scales. Results showed that while Japanese-accented English received less favorable ratings on the Status and Solidarity dimensions on a statistically significant level, the small effect size may have indicated that the differences were negligible. Interpreting the results from the data through the World Englishes Kachruvian paradigm, it is argued that …

Opportunity Identification For New Product Planning: Ontological Semantic Patent Classification, Farshad Madani

Dissertations and Theses

Intelligence tools have been developed and applied widely in many different areas in engineering, business and management. Many commercialized tools for business intelligence are available in the market. However, no practically useful tools for technology intelligence are available at this time, and very little academic research in technology intelligence methods has been conducted to date.

Patent databases are the most important data source for technology intelligence tools, but patents inherently contain unstructured data. Consequently, extracting text data from patent databases, converting that data to meaningful information and generating useful knowledge from this information become complex tasks. These tasks are currently …

Organizational Calling And Safety: The Role Of Workload And Supervisor Support, Layla Rhiannon Mansfield

Dissertations and Theses

Research suggests that individuals who perceive their work as a calling (a deep passion and meaningfulness associated with a certain domain) experience a variety of positive outcomes such as occupational identification, career decidedness, and job satisfaction. Utilizing the tenets of Social Exchange Theory and the Job Demands Resources Model, I proposed that individuals with greater calling toward their occupation will report higher safety motivation and safety compliance. However, under conditions of high workload this relationship would be attenuated. Further, by the same rationale, individuals with lower calling will report lower safety outcomes, yet I proposed that this relationship is mitigated …

Hierarchical Random Boolean Network Reservoirs, Sai Kiran Cherupally

Dissertations and Theses

Reservoir Computing (RC) is an emerging Machine Learning (ML) paradigm. RC systems contain randomly assembled computing devices and can be trained to solve complex temporal tasks. These systems are computationally cheaper to train than other ML paradigms such as recurrent neural networks, and they can also be trained to solve multiple tasks simultaneously. Further, hierarchical RC systems with fixed topologies, were shown to outperform monolithic RC systems by up to 40% when solving temporal tasks. Although the performance of monolithic RC networks was shown to improve with increasing network size, building large monolithic networks may be challenging, for example because …

Recent Advances In Activity-Based Travel Demand Models For Greater Flexibility, Kihong Kim

Dissertations and Theses

Most existing activity-based travel demand models are implemented in a tour-based microsimulation framework. Due to the significant computational and data storage benefits, the demand microsimulation allows a greater amount of flexibility in terms of demographic market segmentation, temporal scale, and spatial resolution, and thus the models can represent a wider range of travel behavior aspects associated with various policies and scenarios. This dissertation proposes three innovative methodologies, one for each of the three key dimensions, to fulfill the greater level of details toward a more mature state of activity-based travel demand models.

Exploring Technology Forecasting And Its Implications For Strategic Technology Planning, Yonghee Cho

Dissertations and Theses

As the importance of R&D has been growing in economic growth, the accountability and effectiveness of R&D programs are highly emphasized. Especially, in times of economic downturn, the evaluation of performance in a firm is needed to justify R&D investment. In response, various attempts have been made to improve success rates of R&D projects, gain competitive advantage, and achieve a firm's growth in profitability. In particular, in industries where technological innovation is significant, strategic technology planning and R&D capabilities may be the lead ones in defining the dynamic capabilities of a firm. In addition, technology forecasting (TF) in technology planning …

Financial Strain And The Work-Home Interface: A Test Of The Work-Home Resources Model From The Study For Employment Retention Of Veterans (Serve), Mackenna Laine Perry

Dissertations and Theses

Money is consistently one of the most common and significant sources of stress in America. The American Psychological Association's annual Stress in America survey has found that money and work have been two of the top sources of "very" or "somewhat" significant stress for Americans since 2007, when the first report was released. Drawing upon the work-home resources model, this study examined the longitudinal effects of financial strain as a component of the work-home interface on a sample of 512 employed veterans from the post-9/11 era. The work-home resources model posits that contextual demands and contextual resources in one domain …

Obesity, Type 2 Diabetes, And Dietary Acculturation Among Foreign-Born Blacks In New York City, Margrethe F. Horlyck-Romanovsky

Dissertations and Theses

Background: Black immigration to the US quadrupled between 1980 and 2000, and between 2000 and 2013 it further increased by 56%. The US Census estimates that by 2060, 16.5% of the US Black population will be foreign-born. Half of all foreign-born Blacks (FBBs) in the US, or more than 1.9 million people, are from the Caribbean, and of those, 682,000 were born in Jamaica alone. Besides the Caribbean, there are 1.36 million immigrants from sub-Saharan Africa. In New York City, non-Hispanic black Caribbean and West African immigrants constitute 19% and 4%, respectively, of the total foreign-born population. Research is limited …

Sosiel: A Cognitive, Multi-Agent, And Knowledge-Based Platform For Modeling Boundedly-Rational Decision-Making, Garry Sotnik

Dissertations and Theses

Decision-related activities, such as bottom-up and top-down policy development, analysis, and planning, stand to benefit from the development and application of computer-based models that are capable of representing spatiotemporal social human behavior in local contexts. This is especially the case with our efforts to understand and search for ways to mitigate the context-specific effects of climate change, in which case such models need to include interacting social and ecological components. The development and application of such models has been significantly hindered by the challenges in designing artificial agents whose behavior is grounded in both empirical evidence and theory and in …

Student Motivation Profiles As A Diagnostic Tool To Help Teachers Provide Targeted Support, Cailin Tricia Currie

Dissertations and Theses

Research has demonstrated that academic engagement is an important resource for students, promoting their learning and achievement. Less well documented is the possibility that students' classroom engagement may also be a valuable resource for their teachers, capable of influencing how teachers treat their students over time. The current study sought to examine the relationship between student motivation and teacher behavior to better understand how teachers perceive and respond to their students' classroom motivation and whether these motivational states contain diagnostic information about the types of supports students may need in order to be engaged, enthusiastic learners. The observable manifestations of …

Modeling The Co-Production Of Public Sector Innovation: Strategic Dimensions Of Organizational Innovation Within The Public Maritime Ports Of The Pacific Northwest, Christopher R. Davis

Dissertations and Theses

Innovation is vital to employing resources in times when the complexity and the demand for public goods and services strain organizational capacities. While innovation in the private sector is the subject of intense academic interest, the study of this phenomenon in the public sector pales in comparison. This is troubling because innovation is an important tool for overcoming resource limitations that plague the public sector. This dissertation's unique contribution to the field is the creation and empirical validation of a model that explains and predicts the co-production of public sector innovation. The model explains the causal mechanism of innovation and …

Lighter Than I Remember, Shane Hayden

Dissertations and Theses

It is pointless to track one's progress along the energies of the cosmic sea, when independent of the immensely malleable sonic waves, and erase the cessation of elevation. The release never reaches the essence and the static repels them when they are devoid of the white dwarfs or their spiral arms: there is nothing tangible in not exploiting the mind/body connection. At last the summit is exalted. Miniscule solar rays expand into darkness, unhinged and must be nurtured, thought by thought, until magnified in nerve impulse and then put to rest by the still water, thus more quickly compiled, constricted …

Co-Creating Spaces Of Critical Hope Through The Use Of A Psychosocial Peace Building Education Course In Higher Education In Protracted Refugee Context: Kakuma Refugee Camp, Kenya, Staci Bokhee Martin

Dissertations and Theses

An unprecedented 65.6 million persons are forcibly displaced (e.g., refugees, asylum-seekers, IDPs). Half are youth. Hope is often the feeling that sustains youth through intolerable conditions. Basic education in protracted areas is seen as a protective factor that nurtures hope and psychosocial wellbeing in the lives of children and youth. This research sought to extend this concept to the higher education in protracted refugee context, where refugees (ages 18-35) were able to co-create spaces of hope that recognized their own agency and their ability to question the status quo while developing critical thinking skills. Based on a theoretical framework of …

Silicon Compilation And Test For Dataflow Implementations In Gasp And Click, Swetha Mettala Gilla

Dissertations and Theses

Many modern computer systems are distributed over space. Well-known examples are the Internet of Things and IBM's TrueNorth for deep learning applications. At the Asynchronous Research Center (ARC) at Portland State University we build distributed hardware systems using self-timed computation and delay-insensitive communication. Where appropriate, self-timed hardware operations can reduce average and peak power, energy, latency, and electromagnetic interference. Alternatively, self-timed operations can increase throughput, tolerance to delay variations, scalability, and manufacturability.

The design of complex hardware systems requires design automation and support for test, debug, and product characterization.

This thesis focuses on design compilation and test support for dataflow …

Morphological Correlates And Behavioral Functions Of Sound Production In Loricariid Catfish, With A Focus On Pterygoplichthys Pardalis (Castelnau, 1855), Monique Renee Slusher

Dissertations and Theses

The Neotropical catfish Pterygoplichthys pardalis produces a harsh stridulation sound upon manual capture. This stridulation sound is made on the abduction of the pectoral fin spine, and is accomplished by friction of a ridged dorsal condyle against a rough spinal fossa of the cleithrum in the pectoral girdle. The sound produced has an average frequency of 121 Hz, and is used with other anti-predator adaptations such as bony subdermal armor and defensive fin-spreading. Pterygoplichthys pardalis does not display behavioral modification in response to conspecific stridulation sound, and therefore it is likely that stridulation sound in P. pardalis is being used …

Stress Analysis Of Embedded Devices Under Thermal Cycling, Sadhana Radhakrishnan

Dissertations and Theses

Embedded active and passive devices has been increasingly used by in order to integrate more functions inside the same or smaller size device and to meet the need for better electrical performance of the component assemblies.

Solder joints have been used in the electronic industry as both structural and electrical interconnections between electronic packages and printed circuit boards (PCB). When solder joints are under thermal cyclic loading, mismatch in coefficients of thermal expansion (CTE) between the printed circuit boards and the solder balls creates thermal strains and stresses on the joints, which may finally result in cracking. Consequently, the mechanical …

Water Transport In The Lateral Line Canal Of The Intertidal Fish Xiphister Mucosus (Girard 1858) And Its Significance To Evaporative Water With Preliminary Observations Of The Metabolic Consequences Of Water Loss, Whitney Anne Gayer

Dissertations and Theses

The lateral line canal system is a sensory organ found in all teleost fish that has a wide range of morphological variation. Variation in morphology may often be the result of evolutionary necessity where the need for function dictates form. Xiphister mucosus is an amphibious Stichaeid fish that inhabits the rocky intertidal zone of the northeastern Pacific Ocean. The rocky intertidal is considered an extreme environment where crashing waves and ebbing tides may require the specialization of adaptations for surviving the many abiotic stressors encountered there.

The lateral line trunk canal of Xiphister is regarded as unique among teleosts with …

At The Trail's End, Naomi Marshall

Dissertations and Theses

Oregon City lies at the base of Willamette Falls. It was one of the few known points in the Oregon Territory, as the destination for thousands coming overland to lay claim to the acres upon acres of forested land. Presently, Oregon City is known by its proximity to Portland. The two neighboring settlements were considered "long-distance," when on a spring evening in 1889, energy generated from the falls was carried through 14 miles of recently-laid copper wire to power streetlights in downtown Portland's Chapman Square. It was the first ever long-distance transmission of electricity. Oregon City, the oldest incorporated settlement …

Development Of A Design Guideline For Bridge Pile Foundations Subjected To Liquefaction Induced Lateral Spreading, Jonathan A. Nasr

Dissertations and Theses

Effective-stress nonlinear dynamic analyses (NDA) were performed for piles in liquefiable sloped ground to assess how inertia and liquefaction-induced lateral spreading combine in long-duration vs. short-duration earthquakes. A parametric study was performed using input motions from subduction and crustal earthquakes covering a wide range of earthquake durations. The NDA results were used to evaluate the accuracy of the equivalent static analysis (ESA) recommended by Caltrans/ODOT for estimating pile demands. Finally, the NDA results were used to develop new ESA methods to combine inertial and lateral spreading loads for estimating elastic and inelastic pile demands.

The NDA results showed that pile …

Mechanisms And Identification Of Unsteady Separation Development And Remediation, Matthew Scott Melius

Dissertations and Theses

Unsteady flow separation represents a highly complex and important area of study within fluid mechanics. The extent of separation and specific time scales over which it occurs are not fully understood and has significant consequences in numerous industrial applications such as helicopters, jet engines, hydroelectric turbines and wind turbines. A direct consequence of unsteady separation is the erratic movement of the separation point which causes highly dynamic and unpredictable loads on an airfoil. Current computational models underestimate the aerodynamic loads due to the inaccurate prediction of the emergence and severity of unsteady flow separation especially in response to a sudden …

Strong Coupling Between Photonic Cavities, Xiang Wei

Dissertations and Theses

As the performance of computers has improved dramatically since the 1990s, many interesting photonic crystal properties have been theoretically and experimentally discovered. For example, the strong coupling between photonic crystal cavities was revealed in the 2000s; many groups have successfully fabricated these cavities and verified strong coupling experimentally using silicon. In this thesis, instead of using silicon, we present new results on photonic crystals made by thin indium tin oxide (ITO) layers. Compared to silicon, ITO is not an ideal material to make a photonic crystal because of its comparatively low refractive index and limited transparency. However, it is an …

Whether, When, And How: Fertility Intentions And Age In The U.S., Andrea Melnikas

Dissertations and Theses

Thinking about, planning for, and having children is a deeply personal experience influenced by myriad factors at individual, intrapersonal, community and larger social levels. Examining fertility intentions is of interest to researchers from numerous social science disciplines in part because these intentions are potentially tied to larger demographic and economic shifts. In recent years in the U.S. the mean age at first birth has been increasing, with more women of older ages (age 35 and older) giving birth, due to both delays in childbearing that accompanied larger social trends such as increased educational and career opportunities and a decrease in …

Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars, Ari Koeppel

Dissertations and Theses

Asteroid bombardment contributed to extensive melting and resurfacing of ancient (> 3 Ga) Mars, thereby influencing the early evolution of the Martian crust. However, information about how impact melting has altered Mars’ crustal petrology is limited. Evidence from some of the largest impact structures on Earth, such as Sudbury and Manicouagan, suggests that some impact melt sheets experience chemical differentiation. If these processes occur on Mars, we expect to observe differentiated igneous materials in some exhumed rock samples. Some rocks observed in Gale crater are enriched in alkalis (up to 14 wt% Na₂O + K₂O) and …