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The acquisition of additive focus particles: Children's understanding of their presuppositional and focus-sensitive nature
No full textPrevious comprehension studies on the acquisition of additive particles report that children’s understanding of the presuppositional nature of additive particles begins emerging around age 3 but children do not come to understand the focus-sensitive nature of additive particles until much later, possibly after preschool years. These studies, however, involve methodological confounds that could have affected children’s performance, which might obscure our assessment of children’s linguistic capacity. To better understand what children really know about additive particles, it is necessary that we examine whether previous studies underestimate/overestimate children’s performance, because only then can we be confident that our assessment of children’s linguistic capacity is accurate and precise.In light of the above discussion, this dissertation devotes itself to exploring the acquisition of the English additive particles also and too, and their Japanese counterpart mo ‘also/too’. The dissertation presents findings from four experimental studies, which were conducted with the aim of better understanding how English- and Japanese-acquiring preschoolers come to acquire the presuppositional and focus-sensitive nature of the respective particle(s) in their target language.
Experiment 1, Experiment 2, and Experiment 3 examine English- and Japanese-acquiring children’s understanding of the presuppositional nature of additive particles by testing to see if they can differentiate sentences with also/too/mo from those without. The experiments were conducted using a novel task that was designed to test children’s interpretation of sentences containing an additive particle in its naturally occurring context, without having to rely on truth-verification. The results from these experiments provide an important steppingstone for testing children’s understanding of too’ focus-sensitive nature in Experiment 4. Using a novel task that takes on the form of Guess Who? game, Experiment 4 examines children’s understanding of the focus-sensitive nature of additive particles by testing to see if they are able to discern sentences containing a subject-associated too from sentences containing an object-associated too. Together, these experiments contribute novel findings to the acquisition literature.
In addition to the four experiments, the dissertation also presents a supplementary corpus study, which was conducted with the aim of examining whether any evidence for too’s presuppositional and focus-sensitive nature exists in child input. The results from the corpus study provide valuable insights about how children might come to acquire the meaning of additive particles
NEIGHBORHOOD SOCIOECONOMIC STATUS, UTILIZATION AND SHORT-TERM POSTOPERATIVE OUTCOMES FOLLOWING BARIATRIC SURGERY IN MARYLAND
No full textIntroduction: Bariatric surgery is an effective and evidence-based treatment for severe obesity; however, socioeconomic disparities in utilization and outcomes persist. This dissertation comprises three interrelated studies aimed at examining the impact of neighborhood socioeconomic status (nSES), as measured by the Distressed Communities Index (DCI), on bariatric surgery utilization and short-term postoperative outcomes in Maryland. The moderating role of race and ethnicity is also explored across these domains. Methods: A cross-sectional analysis was conducted using the 2018–2020 Maryland State Inpatient Database, linked with ZIP code-level DCI data. Multivariable logistic regression models were used to assess associations between nSES and (1) bariatric surgery utilization, (2) short-term postoperative complications, and (3) healthcare quality measures, including length of hospital stay and 30-day readmissions. Interaction terms and marginal effects were used to evaluate race/ethnicity as a potential effect modifier.
Results: Study I demonstrated that bariatric surgery utilization declined significantly with increasing neighborhood distress. Patients from distressed areas had 31% lower odds of undergoing bariatric surgery compared to those from prosperous neighborhoods (OR: 0.69, 95% CI: 0.63–0.76). Race significantly modified this association: Black individuals were more likely than White individuals to undergo surgery across all nSES levels, with the largest differences observed in the most distressed communities.
Study II found no statistically significant association between nSES and short-term postoperative complications, including gastrointestinal leaks, venous thromboembolism, and gastrointestinal bleeding. Race and ethnicity did not significantly modify these relationships.
Study III revealed no significant associations between nSES and healthcare quality measures, including prolonged hospital stays and readmissions. Similarly, no interaction effects were observed by race or ethnicity for these outcomes.
Conclusion: Neighborhood socioeconomic disadvantage was associated with reduced bariatric surgery utilization, particularly among individuals residing in distressed communities. However, nSES was not significantly associated with short-term surgical outcomes or healthcare quality metrics. Racial differences in surgery utilization persisted across all nSES levels, underscoring the importance of intersectional approaches to addressing inequities in access to bariatric surgery
Local Initiatives Support Corporation Housing in the Blue Line Corridor
No full textFinal report for BUSM 758Z: Integrative Capstone (Spring 2025). University of Maryland, College ParkThis project supports LISC DC’s mission of inclusive economic development by focusing on the Blue Line Corridor in Prince George’s County, an area with untapped potential and strong community roots. Through this initiative, we aim to develop a strategic roadmap for small business growth in two target industries: construction/sustainability and technology/artificial intelligence. Our work includes identifying existing businesses, evaluating their economic impact, and proposing actionable strategies to foster a resilient, community-centered small business ecosystem. This effort aligns with LISC’s Community-Centered Economic Inclusion Framework and contributes to long-term, equitable development in the region.Prince George's County, M
EXPLORATION OF EARTH'S INTERIOR THROUGH TUNGSTEN ISOTOPE GEOCHEMISTRY OF THE HAWAIIAN MANTLE PLUME
No full textThe advancement of analytical techniques has enabled the discovery of µ182W (the parts-per-million deviation of 182W/184W relative to the presumed composition of the bulk silicate Earth) isotopic differences among Earth materials. Variations in µ182W are particularly useful for probing early Earth events because radiogenic 182W was only produced during the initial ~60 million years of the Solar System, requiring anomalous µ182W in the modern mantle to have formed and been preserved for over 4.5 billion years. Characterization of µ182W in modern ocean island basalts (OIB) has revealed that some mantle plumes contain µ182W deficits in one or more of their source components. Investigation of the well characterized Hawaiian mantle plume, from a single volcano scale to the archipelago scale, provides new insights into the materials and processes that affect the expression of µ182W in erupted OIB. In Chapter 2, a systematic study of the Mauna Kea volcano indicates that the anomalous µ182W is present in small volumes, such that it is not always sampled by melting events, even when present in the mantle source of a volcano. Through a two-step acid leaching procedure on ~5 Ma powders from Kauai, Chapter 3 confirms that the µ182W measured in minimally altered, subaerial OIB is a reliable tracer of the mantle source composition. Throughout fourteen volcanic centers in the archipelago, Chapter 4 concludes there are gaps in the plume, where no anomalous µ182W component is present, which could reflect inconsistent entrainment of the anomalous mantle source. The chemical characteristics of Hawaiian lavas with µ182W deficits, both within and among volcanic centers, suggest that the anomalous component in the Hawaiian plume is relatively refractory, is associated with relatively radiogenic 208Pb/204Pb, and is enriched in Ti and Nb, relative to similarly incompatible elements. The probability of a Hawaiian volcano expressing negative µ182W is related to the thermal and physical structure of the plume, such that higher mantle potential temperature and magmatic flux are more likely to produce lavas with anomalous µ182W
Towards Learning Non-Spurious Function: From Representation to Decision Through Data and Model Design
No full textModern machine learning models, particularly deep neural networks, have demonstrated remarkable capabilities across a variety of tasks. However, their success often hinges not only on model capacity but also on the structure of the data and the presence of spurious correlations. This dissertation investigates the foundations of learning non-spurious decision functions—functions that capture stable, generalizable patterns rather than superficial artifacts in the data.
We begin by analyzing the expressive power of neural networks, defined by the function classes that different architectures can represent. In contrast to traditional approaches that fix model structure a priori, we propose a data-informed perspective, where structural choices are guided by the information content and complexity of the data. This view enables more efficient and targeted model designs that align with the intrinsic learning task.
Building on this foundation, we explore how models trained on observational datasets are prone to learning spurious shortcuts, particularly when superficial features correlate with labels. We study the conditions under which such behavior emerges and propose methods to encourage the learning of non-spurious functions through structural and algorithmic interventions.
Together, these contributions offer a unified framework that connects model expressivity, feature representation, and structural design. Our goal is to inform the development of learning systems that not only perform well empirically, but also base their decisions on meaningful, generalizable signals in the data
APPLYING POLICY GRADIENT METHODS TO OPEN-ENDED DOMAINS
No full textDeep reinforcement learning (RL) has been successfully used to train agents in complex video game environments including Starcraft 2, Dota 2, Minecraft, and Gran Turismo. Each of these projects utilized curriculum learning to train agents more efficiently. However, systematic investigations of curriculum learning are limited and it is rarely studied outside of toy research environments. Modern RL methods still struggle in stochastic, sparse-reward environments with long planning horizons. This thesis studies these challenges from multiple perspectives to develop a stronger empirical understanding of curriculum learning in complex environments. By introducing novel visualization techniques for reward surfaces and empirically investigating key implementation details, it explores why policy gradient methods alone are insufficient for sparse-reward tasks. These findings motivate the use of curriculum learning to decompose problems into learnable subtasks and to prioritize learnable objectives. Building on these insights, this dissertation presents a general-purpose library for curriculum learning and uses it to evaluate popular automatic curriculum learning algorithms on challenging RL environments. Curricula have historically been effective for training reinforcement learning agents, and a fundamental understanding of automatic curriculum learning is an essential step toward developing generally capable agents in open-ended environments
AN EXPLORATION OF THE SELECTED PIANO MUSIC OF FREDERIC CHOPIN AND ALEXANDER SCRIABIN
No full textThis dissertation is grounded in three recitals, each featuring works by Frederic Chopin (1810-1849) and Alexander Scriabin (1872-1915). Scriabin, as a devoted follower of Chopin’s aesthetic ideals, filled his early and middle-period works with abundant Chopinesque idioms. However, as will be discussed later, even in his juvenile compositions – beneath the surface of apparent imitation – we can discern flashes of his innate genius. These intuitive musical instincts would later evolve into systematic and substantial innovations during his mature period.
Both composers excelled in crafting concise, impactful genres such as preludes, nocturnes, etudes, and mazurkas – all of which were included in the dissertation. Beyond their mastery of smaller forms, both composers also demonstrated remarkable command over large-scale works. Two fantasies and two concertos were chosen as primary subjects to perform and research. To better illustrate the relationship, repertoires are chosen from Scriabin's early to mid-period, as they remain stylistically Romantic and has strong resemblance to Chopin's aesthetic tastes
Modeling Superconducting Circuits for Quantum Computing and Quantum Sensing Applications
No full textSuperconducting circuits are at the forefront of quantum computing and quantum sensing technologies, where accurate modeling and simulation are crucial for understanding and optimizing their performance. In this dissertation, we study modeling techniques and novel device designs to advance these technologies, focusing on efficient simulations, direct velocity measurement, and nonreciprocal devices for quantum information processing. First, we investigate the use of discrete variable representations~(DVRs) to numerically represent superconducting circuits, exploring their use and effectiveness in several prototypical examples. We find that not only are these DVRs capable of achieving decoherence-accurate simulation, i.e., accuracy at the resolution of experiments subject to decay, decoherence, and dephasing, they also demonstrate improvements in efficiency with smaller basis sizes and better convergence over current standard approaches, showing that DVRs are an advantageous alternative for representing superconducting circuits.
We then consider a specific quantum sensing application, direct velocity measurement in superconducting circuits. We propose and characterize theoretical models for backaction evading, direct velocity measurement that utilize traditional electric and magnetic transducers. We consider the readout of this signal via electric or magnetic field sensing by creating generic models analogous to the standard optomechanical position-sensing problem, thereby facilitating the assessment of measurement-added noise. Using simple models that characterize a wide range of transducers, we find that the choice of readout scheme --- voltage or current --- for each mechanical detector configuration implies access to either the position or velocity of the mechanical sub-system.
Finally, we explore the application of superconducting circuits in nonreciprocal devices, such as circulators. Commercial circulators in the microwave domain typically use ferromagnetic materials and wave interference, requiring large devices and large magnetic fields. However, quantum information devices for sensing and computation require small sizes, lower fields, and better on-chip integration. Equivalences to ferromagnetic order --- such as the model --- can be realized at much lower magnetic fields by using arrays of superconducting islands connected by Josephson junctions. Here we show that the quantum-coherent motion of a single vortex in such an array suffices to induce nonreciprocal behavior, enabling a small-scale, moderate-bandwidth, and low insertion loss circulator at very low magnetic fields and at microwave frequencies relevant for experiments with qubits
LIV-00456: Lithic Procurement and Land Use Strategies Within the Vicinity of the Livengood Dome Chert Formation in the Yukon-Tanana Uplands, Alaska
No full textLIV-00456 is a pre-contact archaeological site identified during the proposed realignment of the Dalton Highway in central interior Alaska. This site is located on the Livengood Dome Chert Formation among many co-related sites situated in a landscape within the Yukon-Tanana Uplands, where primary lithic raw materials are easily accessed in an elevated feature that would have provided good viewsheds of the Tanana-Yukon lowlands. The diverse data presented in this thesis offer insight into the following questions: What was the function of LIV-00456 through time? And how does the site fit into ancient regional landscape use patterns? Indicating that LIV-00456 was integrated into a comprehensive network of ancient land utilization, which prioritized lithic raw material procurement and hunting activities, this pattern exemplifies logistical short-term occupation with instances of reoccupation extending over several thousand years. The geoarchaeological data, which included environmental magnetic susceptibility (EMS) and sediment acidity (pH)/conductivity, along with the lithic data, support the site's temporal association with the middle to late Holocene, in association with the Northern Archaic and Dené traditions
COMPONENT SELECTION FOR USE BEYOND MANUFACTURERS’ TEMPERATURE SPECIFICATION
No full textProducts in many industries need electronic parts that can operate over wide temperature ranges. Electronic parts may not consistently be rated to meet the application requirements. The uprating process was developed in the late 1990s as a possible method to address this problem. Uprating is a process to assess the ability of a part to meet the functionality and performance requirements of the applications in which the part is used outside the manufacturer’s specification range. Uprating is built into the performance assessment step as part of the part selection and management process and requires validation through electrical testing. This process can be resource-intensive in terms of time and money, and it is becoming increasingly so with the increase in part complexity. Therefore, there is a need to preselect parts that have the potential to be uprated. This thesis developed an uprateability assessment process to facilitate this pre-selection. This process depends on the thermal information provided in recommended operating conditions and absolute maximum ratings.In this thesis, a quantitative analysis of 140 datasheets is performed to identify the trends in published thermal information for absolute maximum ratings, recommended operating conditions, assembly information, thermal resistances, and temperature dependence of electrical parameters. The analysis identifies the best practices, inconsistencies, and incompleteness in the information provided by the manufacturers. This thesis provides a methodology to establish recommended operating conditions and absolute maximum ratings when unavailable in the datasheets. It outlines the criteria necessary to verify a comprehensive rating section, assigning an information availability level to the thermal ratings to assess the quality of the information provided by the manufacturer, and recommends sources to obtain the missing information.
This thesis also provides an uprateability assessment methodology to identify the components that have the potential to be uprated out of an initial pool of components. The goal is not to uprate all components under consideration but to identify the potential ones that are likely to succeed before they are experimentally evaluated. This process evaluates and eliminates the parts that cannot be uprated, narrowing the potential candidates for uprating and reducing experimental costs