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Built In Reefscape
No full textIn the face of climate change and rising sea levels, the most common response is to prepare for human migration inland and to implement more protections of coastal communities. A different approach considers the migration of human communities out to sea. Coral reefs and adjacent coastal habitats are biodiverse, life-supporting, but also suffer from the effects of climate change, pollution, and collisions, leading them to rely on human efforts to restore and implement protections. The relationship between reefs and humans can be strengthened to encourage environmental stewardship and also explore how to better live in marine ecosystems. This thesis will ask how can architects be inspired by the mechanics and processes of reef organisms to design a system that creates built environments that support a reciprocal relationship between humans and marine wildlife
ASSOCIATIONS BETWEEN TEMPERAMENT PROFILES AND SOCIAL DEVELOPMENT IN EARLY CHILDHOOD
No full textThe relationship between several dimensions of temperament and children’s social development has been extensively examined, yet most of the extant literature has focused on the isolated impact of specific temperamental characteristics. Person-centered or profile-based approaches, on the other hand, account for complex combinations of multiple traits within an individual. This study seeks to adopt a person-centered approach to examine the concurrent relationship between previously generated profiles of parent-rated and teacher-rated temperament and psychosocial functioning in early-childhood. Person-centered analysis has the capacity to move beyond the identification of narrow risk factors to characterize groups of children who respond similarly to environmental demands and require similar levels of support. To examine the relationship between temperament profile membership and concurrent internalizing problem behaviors, externalizing problem behaviors, and social skills, multiple iterations of the modified BCH procedure were performed. Wald’s chi-squared, pairwise comparison tests were then implemented to explore how different temperamental groups diverged in their expression of problem behaviors and social functioning. Across home and school environments, higher levels of exuberance, greater negative emotionality, and lower behavioral regulation contributed to increased externalizing behavior concerns, whereas lower levels of exuberance, greater negative emotionally, and lower perceptual sensitivity contributed to greater internalizing behavior concerns. Analyses regarding the influence of temperament profile membership on social outcomes demonstrated that extreme levels of perceptual sensitivity, higher levels of exuberance, greater negative emotionality, and lower behavioral regulation contributed to weaker social functioning. Associations between perceptual sensitivity and psychosocial outcomes suggested a more complex relationship that was maintained by emotional regulation or soothability. Additionally, children’s self-regulation demonstrated considerable nuance, such that subtle differences in the specific types of self-regulation asserted greater implications on the estimation of overall problem behaviors and social functioning. These results were commensurate with patterns found in existing literature regarding the complex influence of temperament on social developmental outcomes. A few of the current findings also provided novel insight to unique interactions among temperament characteristics that, to the author’s knowledge, have never been explored with person-centered models before. The results of the current study supplemented the field’s current comprehension of temperament and contributed to more meaningful accommodation of children’s individual differences. Continued replication of person-centered literate establishes credibility for profile-based approaches in explaining the processes of child temperament and addressing children’s psychosocial challenges in many different settings. Future person-research centered research should continue to examine the relationship between wide-ranging collections of temperament traits on social-developmental outcomes in a variety of contexts
DETECTION AND SUPPRESSION OF AN INCIPIENT FIRE USING A UAV
No full textThis thesis investigates the development of an Uncrewed Aerial Vehicle (UAV) system designed to detect, localize, and suppress incipient wildfires. The system is designed with a commercial UAV in mind, but with an emphasis on the scalability and portability of its components. The key contributions of this research are the design and testing of a multi-spectral fire detection algorithm utilized in broad area surveys, a fire localization routine that utilizes the fire detection data to design an optimized flight path for revisiting potential fire sites, and the integration of a third-party drop system with the commercial UAV in order to deliver suppressant payloads to fire sites. These critical components are combined together to form an end-to-end fire process chain, which fuses autonomous and manual UAV functions into a procedure where one UAV can conduct fire detection, localization, and suppression activities utilizing two different mission profiles. Extensive testing of the fire process chain in totality and across its individual components is conducted, the results are thoroughly analyzed, and suggestions for future wildfire management UAV systems are provided
Everyday Economies: Narratives and Negotiations of Cultural Economic Practices in Langley Park, Maryland
No full textThis dissertation focuses on Langley Park, a tri-jurisdictional suburb of Washington, D.C., primarily inhabited by residents from Latin America, especially Guatemala and El Salvador. Due to its proximity to Washington, D.C., Langley Park is experiencing redevelopment initiatives, particularly as a future transit-oriented development site for the Purple Line light rail. This study explores how Langley Park epitomizes everyday economies, a framework that considers community and diverse, often invisible economies, along with the daily lives of informal vendors, translocal and microbusinesses, and hybrid economies. I investigate how economic survival and networking are integrated into the community's daily practices, social relations, and spatial negotiations through an ethnographic and qualitative approach that was conducted via participant observation, pláticas, semi-structured interviews, visual and material analysis, and archival analysis. In Langley Park, everyday economies have emerged as residents and entrepreneurs navigate historical forms of slow, legal violence and systemic disinvestment. As the Purple Line undergoes construction with a scheduled opening in 2027, the community faces renewed risks of displacement and dispossession. My argument is two-fold: First, I propose that slow, legal violence is a form of displacement experienced by Central American immigrants who have faced ongoing marginalization, forced migration, and dispossession, making them vulnerable to future transit-oriented displacement and at odds with top-down stakeholder visions. Despite these challenges, they have developed cultural and economic practices that reclaim space and support everyday economies. Second, through ethnographic conversations, I contend that economic life is shaped not only by capitalist structures and state policies but is also actively produced through daily acts of care, reciprocity, and resistance. Vendors create translocal marketplaces that blend cultural memory and social media-driven entrepreneurship by preserving and documenting their lived experiences across space and time on digital platforms. While these networks contribute to place and community identity within local, transnational, and translocal economies, they are often excluded from official government discourse and planning projects. This research enhances our understanding of why these networks are crucial for Latinx and Central American immigrant communities, challenging traditional conceptions of community and economic development, where alternative economic activities are fluid, translocal, and interwoven across formal and informal networks that transcend geographical boundaries, blending cultural and economic activities, while enacting citizenship and belonging
Essays on Competition, Consumer Search Frictions, and Vertical Restraints
No full textIn Chapter 2, I study firm price-setting decisions when the distribution of consumer inertia changes following product exits. When a product exits, consumers previously affiliated with that product actively "shop." Competing firms thus face a trade-off in the short-run: attract these consumers via lower prices or higher product quality, or take advantage of reduced competition via higher prices or lower product quality. I leverage a 2008 shock in the market for private Medicare, or Medicare Advantage, that induced insurers to remove 20% of plans nationally to measure this trade-off. I find that plans decrease premiums in the short-run, and increase premiums in the long-run in response to the cancellation event. These findings are consistent with an invest-then-harvest mechanism (Farrell and Klemperer, 2007). I also develop a model of dynamic firm competition to identify the welfare effects of consumer inertia under changes in market structure. In counterfactual exercises, I find that plan bids are 1.35% lower on average when firms assume all consumers actively shop and 0.02% higher on average when firms fail to internalize the marginal increase in actively shopping consumers following the plan exit event.
In Chapter 3, Danial Asmat, Chenyu Yang, and I study minimum advertised price restrictions (MAPs), which are popular vertical restraints. We study retail pricing under MAP using price data of Seagate hard disk drives on U.S. online retailers. The data suggest that MAP is not a form of resale price maintenance. First, we find that retail prices can be significantly lower than MAP. Second, retail prices of products subject to MAP have greater dispersions between retailers. Lastly, retail prices sometimes increase after a MAP decrease. These observations are consistent with the predictions of a search model that interprets MAP as a form of information restraint.
In Chapter 4, I study the price and non-price effects of a merger between two health insurers. Under U.S. antitrust policy, enforcers must identify mergers that are potentially harmful and propose remedies where necessary. I estimate the price, plan star rating, variety, share, and cost effects of Humana's acquisition of Arcadian Management Services (AMS), a Medicare Advantage HMO, and the Department of Justice's subsequent divestiture order to provide insight on antitrust enforcers' success. I find that Humana experienced cost synergies following the merger and passed them through to customers via lower premiums and higher star ratings. AMS plans were canceled almost immediately after they were acquired, reducing product variety. These plans were of a lower quality and beneficiaries in these plans were highly inertial, so AMS variety reductions are unlikely to have caused consumer welfare harms
Work and Well-being Among LGBTQ+ Adults in Unsettled Times
No full textThe rise in precarious employment in recent decades has left a substantial portion of the U.S. workforce in insecure jobs with poor job quality, with the divide between “good” jobs and “bad” jobs becoming even starker during the COVID-19 pandemic. Within this context, little is known about how LGBTQ+ workers (lesbian, gay, bisexual, transgender, nonbinary, queer, or another minoritized sexual or gender identity) are faring, even though previous research suggests they may be among those most vulnerable to negative structural and interpersonal factors affecting workers’ well-being in unequal workplaces. Using a multi-method quantitative and qualitative research approach, this project asks: 1) How are LGBTQ+ adults experiencing and responding to an unequal work landscape in this context? 2) What are the implications for well-being? I investigate these questions by analyzing two data sources: the 2015 National Health Interview Survey (NHIS) Occupational Health Supplement, a nationally-representative survey collected by the Centers for Disease Control and Prevention, and in-depth qualitative interviews with a demographically and occupationally diverse sample of 43 LGBTQ+ workers I conducted for this project. Results from the quantitative analysis of pre-pandemic data suggest employed sexual minority adults are significantly more likely to be exposed to negative temporal and psychosocial job conditions, including work/non-work interference, time urgency, harassment, and limited supervisor support. Compared to heterosexual workers, sexual minority workers overall feel more rushed and less supported on the job. Building on this descriptive documentation, the qualitative analyses used interview data to uncover mechanisms related to inequalities in job quality conditions and experiences. Interview findings showed LGBTQ+ workers emphasized both conventional job quality factors (e.g., pay, benefits, advancement) as well as unique job quality factors (e.g., misgendering, physical and interpersonal safety concerns) as shaping perceptions of what makes a “good” or “bad” job. Taken together, the dissertation makes contributions including: 1) providing the first analysis of how job quality disparities vary by sexual orientation at the national level in the United States; 2) identification of unique mechanisms through which job conditions are associated with well-being across social locations; and 3) new insights into the conceptualization and measurement of job quality in sociological literature
“HOW WE ACCOMPLISH THIS WORK:” BLACK LABOR AND U.S. IMPERIAL PUBLIC HEALTH IN THE GREATER CARIBBEAN, 1898-1934
No full textHow We Accomplish this Work: Black Labor and U.S. Imperial Public Health in the Greater Caribbean, 1898-1934” examines public health as a site of racialization in the transnational historical context of early twentieth century U.S. imperial expansion across the Greater Caribbean. Centering gendered Black labor, I foreground undertheorized disability histories of the Global South and underscore racialized disability as intertwined with the objectives of empire, the hierarchical structures of colonialism and the continued post-emancipation commodification of Black bodies. Post-war celebrations of the United States’ Caribbean empire often point to technological advancements in tropical medicine and sanitation that facilitated white occupation and the growth of tourist economies. I argue, however, that the technological advancements in tropical medicine, public health and sanitation and in infrastructure undergirding the region’s habitability for white U.S. Americans relied on forms of gendered Black labor. This multi-sited project turns to U.S. South (with particular attention to Louisiana), Panamá and Haiti and centers Black public health work, domestic labor, care work and deathcare and construction work, Black experiences of illness, injury and disability, Black intra-regional migration, and Black peoples encounters with state apparatuses, health regulations and medical experimentation. Putting archival public health materials and cultural products in conversation with women of color feminist theories, disability studies, critical race scholarship, and colonial health histories, I analyze how racialized disability is embedded in U.S. imperial public health and in the infrastructural works of territorial expansion
AUTONOMOUS HYBRID AERIAL-TERRESTRIAL TRANSPORT AND RETRIEVAL FOR IN-SITU COLLECTION
No full textThis thesis investigates the use of hybrid vehicles, capable of both aerial and terrestrial motion, for sample search and retrieval, enabling autonomy through the customization of existing software for new applications. This research addresses challenges related to autonomous detection of, and navigation with respect to, fiducial markers - in both the aerial and terrestrial domains. A key contribution of this work is that of the hybrid mobility system, which is capable of transitioning autonomously between flying and driving. To assist in sample detection, an existing software package for fiducial marker recognition is utilized and adapted for localization of the target and positioning of the vehicle for sample collection. For sample collection, a simple gripper is designed to grasp the target object before depositing at a home location. This research leverages software-in-the-loop simulation for validating code performance prior to deployment on the actual vehicle, which is tested in a controlled, indoor laboratory environment
Re-examine the origin of the fall of Qing Dynasty prior to the First Opium War.
No full textFrom the beginning of the study of Qing China, the period between the First Opium War in 1839 and the Boxer Rebellion in 1900 has been extensively researched by various historians in both East and West as the pivotal point for the Qing Dynasty as the irreversible and rapid decline started. However, I intend to further contribute to the research on the period between 1790 and 1839, which some historians have pointed out with a renewed focus as to the origin of the Qing Dynasty’s rapid decline. Therefore, with that research aspect in mind, by reexamining this period between 1790 and the 1830s, this research paper primarily focuses on the financial cost of the White Lotus War, the Qing’s internal expenditures, the Year Without the Summer in 1816, and finally reexamining the true cost of the uncontrolled opium smuggling with the previous events considered. In the end, I am advocating a fresh look at these four critical blows between 1796 and 1830s that were either more or less equal to the aftermath of Western imperialism and the Taiping Rebellion on the Qing Dynasty
EXPLORING VISUAL WORD RECOGNITION IN LATE SECOND LANGUAGE LEARNERS: A FOCUS ON LETTER TRANSPOSITION
No full textPrevious studies in the first language (L1) revealed that letter-transposed (TL) primes (e.g., baisc for basic) have a significant advantage over letter-substituted (SB) primes, although this advantage accompanies a significant cost when compared to identity (ID) primes. These phenomena are often cited as evidence for position-flexible yet precise lexical processing in L1. The present study investigated whether Korean L2 learners of English employ the same processing abilities as native speakers. A lexical decision task using the masked priming paradigm was conducted with 144 English words and 144 nonwords. Targets were preceded by four prime types: ID, TL, SB, and unrelated (UN) primes. Both native speakers and L2 learners exhibited significant TL advantage and cost. However, the two groups differed significantly in the repetition priming effect as well as in the differences between TL and UN conditions, and between the SB and UN conditions. These findings in the L2 learners were not entirely compatible with either the Lexical Tuning Hypothesis (Castles, Davis, Cavalot, & Forster, 2007) or the Multiple Route Model (Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001; Grainger, Lété, Bertand, Dufau, & Ziegler, 2012; Grainger & Ziegler, 2011). Instead, the L2 learners’ performance was primarily influenced by the formal similarity in terms of letter identity and letter position. Thus, high formal similarity between prime and target pairs resulted in faster and more accurate responses to word targets, regardless of prime lexicality. Given that the TL advantage and cost were comparable to native speakers, the results highlight the need for diverse comparisons to appropriately examine L2 visual word recognition