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From Model to Behavior: Methodological Challenges in Using Fuzzy Cognitive Maps to Represent Mental Models
No full textThis dissertation examines the use of Fuzzy cognitive maps (FCMs) as representations of mental models and how these representations connect to individual behavior. Fuzzy cognitive maps (FCMs) are semi-quantitative models that encode cause-and-effect structures as directed graphs. They are frequently used to represent individuals\u27 knowledge structures/mental models and should in theory correlate to actions and decisions of individuals; however, this correlation has yet to be explored in a systematic manner. This dissertation represents the first step in experimental research on the connection between FCMs and individual behavior. It examines two theories of how humans use mental models, one based on simulation, and one based on cues. These two theories are then connected to structural indicators within individual FCMs. These structural indicators are then compared to behavioral survey results from the same individual. No connection is found between the structural indicators and survey results. Analysis of why there is no correlation highlights the difference between methodology-focused research versus subject-based research, along with the challenges of collecting high-quality FCMs from individuals
Design and Evaluation of an Electromagnetic Band Gap Structure for Self-Interference Reduction in mmWave Full-Duplex Systems
No full textFull-duplex (FD) wireless is a new technology that allows a device to transmit and receive at the same time and on the same frequency band. It has the potential to double the capacity and spectral efficiency of a wireless link compared to the family of conventional half-duplex wireless systems. The key challenge in implementing FD wireless communication is self-interference (SI): a node\u27s transmitting signal generates significant interference to its receiver. Several previous studies have demonstrated the potential to reduce SI and develop FD radios; however, these studies are mostly limited to sub-6 GHz systems. Previous and on-going research explored various techniques, including analog self-interference cancellation (SIC), digital self-interference cancellation, passive self-interference cancellation, and combinations of these approaches.
However, at millimeter wave (mmWave) frequencies, the sizes of components decrease significantly in relation to their wavelength, leading to a more compact form factor for mmWave designs. This miniaturization allows for the possibility of innovative FD design approaches; however, it also presents challenges, such as reduced spacing between components. As a result, implementing analog or digital SIC techniques using robust component devices for mmWave radio and wireless applications demand careful consideration and adaptation.
Furthermore, the transceiver architecture developed for FD solutions at sub 6 GHz frequencies requires modifications to effectively transition to mmWave applications, highlighting the need for architectural advancements in both the digital and analog SIC sections of the transceiver. By addressing these challenges, we can improve the performance and functionality of FD mmWave systems.
This dissertation investigates the potential of a passive solution for SIC at the mmWave frequency of 28 GHz. The research study approach involves the design and integration of a novel electromagnetic band gap (EBG) structure within a substrate design of transmit (Tx) and receive (Rx) antenna arrays. The research investigates novel EBG structures aimed at mitigating planar and surface wave coupling between Tx and Rx antennas within the reactive near-field region of the antenna system. By attenuating these undesired coupling mechanisms, the EBG structure effectively reduces SI to levels that permit reliable reception of the desired signal in a FD operation.
The Tx and Rx antenna system considered for this research comprises unit antenna (single Tx and Rx) elements and Multiple Input Multiple output (MIMO) antenna arrays (1x4 and 4x4). The designs were also fabricated for testing, measurement, and comparison to simulation data. The simulation and manufacturing of prototype antenna and novel EBG designs took into account manufacturing process variations, and substrate material permittivity changes due to temperature and humidity effects.
Furthermore, the design of the unit and MIMO antenna array was validated through passive measurement in an anechoic chamber and using a Vector Network Analyzer (VNA) to determine and compare measured antenna performance metrics with simulated data.
The novelty of our EBG designs lies in the substantial reduction of effective capacitance compared to conventional mushroom-type EBG structures operating at 28 GHz. This reduction is achieved through miniaturization of the unit cell, which allows a greater number of EBG elements to be integrated within a fixed footprint. The miniaturization and effective capacitance change of the novel EBG results in enhanced suppression of surface and leaky wave modes. Consequently, the structure provides wideband isolation between the Tx and Rx antenna arrays, significantly improving FD performance for mmWave applications.
Ultimately, this dissertation aims to advance mmWave FD wireless communication by substantially mitigating SI in the passive RF domain. By addressing SI at the physical layer, the approach has the potential to eliminate reliance on complex and bulky analog cancellation circuits, thereby enabling the development of more compact, energy-efficient, and cost-effective mmWave full-duplex radio architectures
Fostering Meaningful Learning: Experiences of Linguistically Diverse Trainers in Early Childhood Care and Education (ECCE) Professional Development
No full textLinguistically diverse trainers play a critical role in reshaping professional development (PD) within Early Childhood Care and Education (ECCE), yet their contributions remain marginalized within English-dominant institutional structures. This qualitative study explored how these trainers define and deliver meaningful learning experiences despite systemic barriers, limited resources, and monolingual policies. Grounded in critical constructivism, the research centered the lived experiences and voices of linguistically diverse trainers across multiple contexts. Through semi-structured interviews, participants shared how they co-constructed relational, culturally grounded, and linguistically affirming PD environments rooted in community knowledge and emotional connection. Findings reveal that meaningful learning occurs when training reflects the cultural realities and linguistic preferences of participants--an outcome trainers achieve by designing the trainings they wish they had received. These trainers provide mentorship, foster community, and reclaim linguistic space in systems that often undervalue their labor. Their work exposes the cost of operating within English-centered systems and the resilience required to sustain culturally relevant pedagogies. This research amplifies the voices of marginalized trainers and offers recommendations for policy and institutional transformation, advocating for equity, funding, and the structural redesign of ECCE professional development to support a multilingual, multicultural workforce
Analyzing National War Propaganda Through Comparison of Diverse Case Studies
No full textIn the build-up to war, national governments utilize propaganda to gather public support for the war effort. In some instances, propaganda campaigns are conducted but war does not occur. This begs the question as to why war follows propaganda campaigns in some cases, but not in others. I argue that propaganda efforts that lead to war can be generally characterized through three major strategies based on a patriotic participatory social structure, a claim to moral authority, and the blending of individual concepts of the state, government and nation. In this study, I analyze the major historical case studies of the Spanish-American war, Imperial Japan, the U.S. invasion of Iraq in 2003, the U.S-Soviet Union Cold War confrontation, and the Kashmir dispute between India and Pakistan to study the relationship between propaganda and war. I use a qualitative content analysis methodology to analyze pro-war statements from politicians, military officials and media leaders to determine the similarities and differences in the language, ideology and framing strategies used in various cases of international conflict. In cases where propaganda campaigns lead to war, I find that appeals based on moral authority, citizen-state participation and the merging of independent notions of statehood, cultural heritage and shared national history are employed by national governments and reiterated by mainstream media. In cases where war did not occur, such as the Cold War and the Kashmir dispute between Indian and Pakistan, the introduction of nuclear weapons and weapons of mass destruction influenced propaganda messaging in a particular manner that discouraged direct intense hostilities in favor of promoting lower intensity conflicts. The findings from this study show that propaganda campaigns continue to have relevance in shaping global conflicts
Japanese and English Code-Mixing: A Study on the Grammar and Functions by L1 Japanese-Speakers in Oregon
No full textThis thesis examines the phenomenon of code-mixing (CM) among speakers of Japanese as their first language (L1) and of English as their second language (L2) residing in Oregon, the United States. Unlike prior studies that focus on early bilinguals or individuals with mixed linguistic and cultural backgrounds, this study specifically target speakers who began learning English in formal settings through compulsory education or a cram school in Japan. After they had completed high school in Japan, they started living in English-speaking countries.
The participants in this study were two communities. Each group recorded their conversations via their own cell phones, and sent the audio files to the researcher. The instances of CM utterances were transcribed and identified by the researcher, and the cases were categorized based on Muysken\u27s (2000) classification. The results revealed that speakers solely employed insertional CM, and there was a complete absence of inter-sentential CM and alternational CM. Furthermore, the vast majority of inserted English items were recategorized into nouns within the matrix Japanese structure from other parts of speech. A number of CM functions were analyzed and appeared to serve communicative purposes such as clarifying meanings, emphasizing a message, and conveying accuracy when quoting.
Overall, the participants\u27 CM exhibited distinctive features that differed from those observed in previous CM research. The speakers consistently integrated the English CM into Japanese phonologically and adhered to Japanese as the morphosyntactic base. Despite following the Japanese matrix system, participants utilized English CM items at the semantic and pragmatic level to broaden their range of expressible meanings
Evaluation of Fano Resonance in Silver Nanotriangles and Complementary Triangular Apertures for Enhanced Refractive Index Sensing
No full textThis thesis presents a detailed investigation of plasmonic sensors based on silver (Ag) nanotriangles, focusing on the interaction of plasmonic mode with waveguide modes to achieve Fano resonance for enhanced refractive index sensitivity. For this purpose, Ag nanotriangles were chemically synthesized and were on indium tin oxide (ITO)-coated glass. The samples were illuminated with laser light of various wavelengths and polarization to excite surface plasmon in the nanotriangle. Observation and characterization of their plasmonic behavior was done experimentally using Photoemission Electron Microscopy (PEEM). Numerical simulations using the Finite Element Method (FEM) were performed that agreed with these experimental results and provided further insight into the plasmonic behavior. Fano resonance condition was studied exclusively through FEM simulations, allowing precise control over geometry, wavelength, and angle of incidence. The simulation revealed that Fano resonance was achieved by coupling surface plasmons in single Ag nanotriangles (excited by edge coupling) to a waveguide mode in the ITO layer through a spacer layer, resulting in asymmetric spectral features. The study was extended to include both 2D and 3D models. In 2D geometries with planar semi-infinite Ag layers, Fano resonances exhibited sharper spectral features, while in 3D nanotriangle configurations, the characteristic asymmetry and spectral narrowing persisted, but spectral features broadened with decreasing size. Additionally, a triangular cavity in Ag layers was investigated based on Babinet\u27s principle, showing stronger plasmonic field enhancement compared to solid nanotriangles. The sensitivity of the Fano resonance of these structures were determined and were compared with the sensitivity of the plasmon resonance by altering the refractive index of the surrounding medium simulating the presence of analytes. In each case the Fano resonance showed higher sensitivity in comparison to plasmon resonance sensitivity in each type of structure. Furthermore, it was seen that Fano resonance showed stronger sensitivity in the Ag cavity in comparison to the Ag solid nanotriangle
Ecological Drivers and Temporal Dynamics of \u3ci\u3eDaphnia\u3c/i\u3e in a Diverse Environmental and Spatial Landscape
No full textIn the modern era, commonly referred to as the Anthropocene, human-caused changes to the environment are prevalent and complex. The study of impacts to biodiversity and ecosystem functioning requires multi-faceted approaches that encompass scales of organization from genes to ecosystems. It is often difficult to tease apart whether species responses to environmental change are due to phenotypic plasticity or genotypic variation. Therefore, it is important to try to understand where variation originated, that is, to link a phenotypic response to a genetic change or to gauge whether the response is from the environment. In addition, neutral genetic variation arising from gene flow or genetic drift structures populations and can be influenced by environmental change. Understanding how phenotypic and genotypic variation originate and are maintained is necessary to better grasp the drivers of and responses to environmental change. In my dissertation, I focused on Daphnia, a cladoceran zooplankter with a diverse life history, genome, and mechanisms of dispersal. My goals were to collect genetic and phenotypic measurements from Daphnia across a diverse and geographically widespread group of lakes and multiple time periods to learn how ecological drivers might structure variation in the face of environmental change.
Lakes possess an island-like nature with well-defined boundaries and are therefore amenable to the study of local individual and population variation, as well as ecological interactions. Additionally, lakes are connected across landscapes to other water bodies, the terrestrial landscape, and the atmosphere. Lakes are also repositories of information over time through accumulation and preservation of physical, chemical, and biological materials in the sediment. In addition, lakes are often home to organisms that have been transported across the intervening landscape, such as plants and zooplankton, through vectors such as wind, water, animals, or even humans.
My study lakes were in the arid Channeled Scablands region of southeast Washington, east of the Cascade Mountain range, including some of the lakes and canal systems of the Columbia Basin Project (CBP). Other study lakes outside of the CBP, while not subject to water construction projects, were also subjected to multiple stressors.
I provide background information about the relevance of lakes and zooplankton, particularly Daphnia to the overall scope of the study in Chapter 1. In Chapter 2, I used population genetic analysis combined with environmental data collected from the study lakes and information on dispersal vectors in this region to model drivers of genetic variation over a broad geographic range. I found both evidence of Daphnia gene flow between two lakes across a highly trafficked interstate corridor and relationships in some lakes between genetic variation and bird dispersal, indicating that this species was dispersed by human and bird vectors. Next, in Chapter 3, I researched changes to Daphnia abundance and size over time in a single lake that had been subjected to known historical anthropogenic changes and contemporary recovery. Daphnia produce resting eggs that are preserved in the sediment and can persist for decades to centuries. In Chapter 3, I compared lake sediment nutrient data to that from preserved resting eggs over approximately 150 years from sediment cores. I found a positive relationship between sediment nutrients and resting egg abundance, allowing a reconstruction of possible environmental variables that highlight trends of a long-term lake restoration effort. Finally, in Chapter 4, I explored Daphnia resting egg size as a proxy for adult female body size from multiple lakes between historical and contemporary time periods. I also evaluated hatching success of resting eggs between time periods. I evaluated relationships between abiotic and biotic variables, as well as hatching success, with resting egg size. I found evidence of shifts in trait richness, which is the range of trait values (here, size), within populations between the contemporary and historical time periods. I also found differences in hatching success between time periods, with higher hatching success in the historical time period.
In this dissertation, I found several trends that inform research into the ecology of lakes, especially how ecological drivers impact variation in the face of environmental change. First, I found patterns in population genetic variation showing that Daphnia is dispersed through diverse modes and had gene flow between lakes, indicating at least some ability to overcome the properties of cyclic parthenogenetic Daphnia populations that can lead to genetic structure from founder effects and local adaptation. My study showed that human-caused dispersal could have a disproportionate impact on Daphnia genetic variation across space. Additionally, I found a positive relationship between Daphnia abundance and nutrients over time, illustrating the sensitivity of populations to changes in environmental conditions. The study of Medical Lake was unique because the Daphnia population response tracked a restoration effort through time but also uncovered eutrophication patterns through the use of paleolimnological methods. Finally, I observed trends in body size over an environmental gradient and time, illustrating that Daphnia individuals respond to environmental changes and that these responses can be monitored over an informative temporal scale by studying sediment cores. I investigated intraspecific trait variation, specifically trait richness of body size, across a large geographic range and across time to understand Daphnia phenotypic variation. I also uncovered novel information on hatching processes of Daphnia, which could have critical impacts on ecological interactions and biodiversity in lakes.
Overall, I pursued several avenues of research that would be useful for management of species and ecosystems in the face of environmental change. Using genetic data to investigate patterns in organisms with diverse dispersal modes can inform how dispersal vectors are structuring populations across space. Research on threatened and endangered species, as well as non-native species could benefit from a closer look at genetic variation in order to see patterns of gene flow or genetic drift. Few lakes have long-term monitoring data, so therefore tracking environmental changes over time is difficult, and is especially useful for understanding baseline conditions for restoration. I found value in reconstructing disturbance and restoration with paleolimnological techniques. Finally, in my last chapter, I evaluated how individual variation in an important functional trait could inform drivers of environmental change. Several global lake management plans incorporate zooplankton as indicator species and this research indicates that those plans should continue and expand. By evaluating Daphnia at multiple scales of biological organization and across time and space, this dissertation uncovered ecological patterns and processes necessary to better understand the impacts anthropogenic change
Prospective Associations Among Loneliness and Health for Servicemembers: Perceived Helplessness and Negative Coping Appraisal As Explanatory Mechanisms
No full textLinks between loneliness and health are robust, though evidence for associations with alcohol use is mixed. Previous research has supported perceived stress as a predictor of alcohol use and as a pathway through which loneliness impacts health over time. Yet findings are primarily limited to civilian samples, and less is known about how loneliness relates to stress and health among service members. The current study explores prospective associations among loneliness, stress, and health (i.e., sleep, alcohol misuse, and psychological distress) within a sample of mostly male service members. We examine two dimensions of perceived stress, perceived helplessness and negative coping appraisal, as explanatory mechanisms. Controlling for baseline stress and health, loneliness predicted perceived helplessness and negative coping appraisal (4-month follow-up); in turn, perceived helplessness and negative coping appraisal predicted insomnia and sleep dissatisfaction; and negative coping appraisal predicted alcohol misuse (indirect effects). Findings support transactional models of stress and the stressor-vulnerability model of alcohol use, revealing that coping appraisals play an important explanatory role for stress-related consequences of loneliness. Further, we provide new insight into mechanisms linking loneliness to alcohol use and sleep, differentiating dimensions of stress and highlighting potential intervention targets
Fathers\u27 Racial Differences in Perceived Workplace-Induced Stereotype Threat: Impacts on Sense of Belonging, Job Satisfaction, and Turnover
No full textBlack fathers (BFs) face unique workplace challenges due to racialized and gendered stereotypes that undermine their legitimacy as men, workers, and parents. Drawing on Stereotype Threat Theory (STT) and Stereotype Embodiment Theory (SET), this study examined how workplace-induced stereotype threat (WIST) affects BFs\u27 job attitudes and turnover intentions (TIs). I hypothesized that BFs would report higher WIST than White fathers (WFs), and that WIST would mediate the effects of race-related perceptions on job satisfaction (JS), sense of belonging (SOB), and TIs. In addition, perceived organizational support (POS) was tested as a moderator on the relationships between WIST and these job-related outcomes. Participants included �� = 244 employed BFs (�� = 145) and WFs (�� = 69) recruited online through advertisements shared by organizations that serve fathers or the Black community. Hypotheses were tested using a path analysis in RStudio. As predicted, BFs reported significantly higher WIST than WFs, along with greater TIs, lower SOB, and marginally lower JS. Indirect effects of race on outcomes through WIST were small and marginally significant for TIs and SOB, but not for job JS. POS strongly predicted higher JS and SOB, and lower TIs, but did not moderate the effects of WIST on these outcomes, as predicted. This study identifies WIST as a chronic psychological stressor that disproportionately affects BFs, driving heightened identity-based vigilance and greater intent to leave than WFs. Although POS improved outcomes overall, it did not buffer the negative effects of WIST for BFs. Findings suggest WIST may, in part, contribute to BFs\u27 lower labor force participation, highlighting the need for targeted interventions that expand current forms of organizational support
Documenting the Effects of Laboratory Sorting in Zooarchaeology: Lessons Learned from the Cixwicn Project
No full textZooarchaeologists routinely analyze assemblages that were initially sorted into major animal type (birds, mammals, fish, invertebrates) by students or lab technicians with varied backgrounds in zooarchaeology. Sorting errors are probably made in this initial phase, which can affect taxonomic representation and understanding of human–animal relationships. Recent study of the immense faunal assemblage (over 1 million NSP [Number of Specimens]) from Čḯxwicən (45CA523), a 2,700-year-old Lower Elwha Klallam village located on the coast of Washington (USA), allows us to systematically analyze trends in sorting errors. For example, 22.6% of the bird bones included in our sample were initially missorted into other taxonomic groups, primarily mammal, but also fish and invertebrate. Fish bones were less frequently missorted, but certain taxa with unusual elements were affected. More than one-fourth (27.3%) of all mammal bone chips (debitage from tool production) were missorted. Failure to recognize and mitigate these errors could lead to significant biases. Lab managers need to recognize the potential for sorting error at the beginning and train lab technicians in the kinds of faunal remains they will be encountering, including distinctive elements. Collaborative researchers need to develop protocols for transferring specimens, and scholars working with “legacy collections” should not assume the collections were sorted correctly