VictorJuiz/thesis huggingface dataset:
Pleistocene-Recent Thermal and Faunal Change in California’s Coastal Marine Habitats

The Pleistocene Epoch (2,588,000 – 11,700 years ago) was characterized by cyclical global change: warming and cooling, sea level rises and subsequent falls. Terraced above the shores of California, coastal uplift has raised and preserved the remains of Pleistocene beaches. Over 150 years of research on this “marine terrace” record has uncovered a dynamic history of climatic and consequent biogeographical change. As such, California’s marine terrace record provides an empirical framework for understanding how thermal change drives biogeographic shifts. But our knowledge of the magnitude of Pleistocene coastal thermal changes, and, the extent to which species’ ranges were impacted, has been limited by the difficulty of precisely dating marine terraces and independently reconstructing their paleoenvironments./nHere, I leverage recent advances in geochronology and paleo-thermometry to revisit the marine terraces of California. In Chapter I, I introduce this classic paleoecological system and review its major contributions to natural history. In Chapter II, I use bulk and clumped stable isotope paleothermometry to provide clarity on the magnitude of thermal change observed within coastal marine habitats during several Pleistocene climate states, including the Marine Isotope Substages (MIS) 5a (~80,000 years ago) and 5e (~120,000 years ago). In Chapter III, I compare paleo-temperature reconstructions to their associated mollusk communities to test whether species lived within their present-day thermal niches during the Pleistocene. In Chapter IV, I compile marine terrace localities radiometrically dated to MIS 5e—the warmest climate state of the last 300,000 years—to analyze the environmental characteristics of presently extralimital species. And finally, in Chapter V, I synthesize my findings in the context of contemporary change./nI find that Pleistocene paleo-temperatures were ~2.5°C cooler than present for MIS 5a and similar to at present for MIS 5e open-coast habitats. All fossil species occurrences fall well inside their present-day thermal niches, thereby indicating that coastal marine mollusks have tracked stable thermal niches over Pleistocene timescales. I further find that ~15% of species found in southern California during MIS 5e have since been extirpated to warmer southern waters and that these species range into cooler subtropical regions at higher rates than their conterminous faunas. Taken together, these findings portend that contemporary climate change will welcome the establishment of subtropical invasive species once regional warming suffices to allow southern mollusks to track their thermal ranges up California’s coast.

Advisor: Finnegan, Seth
Controlling Crystallization and Transport in Metal–Organic Frameworks

This dissertation documents efforts to control and take advantage of crystallization handles in metal–organic framework synthesis. Understanding fundamental processes during synthesis allows for directed, predictable control over crystallite size and shape, which is demonstrated to play a role in intracrystalline diffusion./nChapter 1 first introduces a summary of crystallization and transport in porous materials, including classical and non-classical models of crystallization, homogeneous and heterogeneous nucleation, and mass transfer resistances. The application of these concepts to metal–organic frameworks is presented alongside common synthetic strategies, coordination modulation and other strategies to control crystallite size and shape, and the potential for non-coordinating bases and buffers to help alleviate some complicating factors common to framework synthesis. Finally, because crystallite size and shape can control intracrystalline path lengths, an introduction to mass transfer resistances is given, including intracrystalline diffusion. Different methods of measuring diffusion in porous materials are presented, including the technique applied in this work, zero-length column chromatography (ZLC)./nChapter 2 details success in deconvoluting solution equilibria during hydrothermal metal–organic framework synthesis. The use of non-coordinating bases and anions allows for generalizable increase in crystallite size. Further, non-coordinating buffers may be used during synthesis to add or subtract individual coordinating anions at a given pH. This strategy allows for tunable and predictable control over aspect ratio in a one-dimensional metal–organic framework./nChapter 3 describes the discovery and utilization of interfacial effects during hydrothermal synthesis to control crystalline phase and size. Controlling the interface between reaction vessel and solution via silanization is found to decrease morphological distribution, change the phase produced for stock solutions, and in some cases, increase crystallite volume by several orders of magnitude./nChapter 4 details the assembly and usage of a ZLC instrument capable of differentiating between different mass transfer resistances. Design considerations and instrument improvements are described. The instrument is used to probe CO2 diffusion within very large crystallites (up to 700 microns in length) of Zn2(dobdc), where surface resistances and defects are proposed to account for a lower diffusivity measured via ZLC versus pulsed-field gradient NMR. Synthetic control over Co2(dobdc) path length is demonstrated to bring about improved mass transfer resistances via path length control for the industrially important molecule m-xylene.

Advisor: Long, Jeffrey R.
Quantum Simulation with Superconducting Circuits

Nonlinear superconducting circuits are a leading candidate to implement quantum information tasks beyond the reach of classical processors. One such task, quantum simulation, involves using a controllable quantum system to study the dynamics of another. In this thesis, we present a series of experiments using small systems of superconducting circuits to perform various quantum tasks relevant to quantum simulation./nIn the first experiment, we design and build a circuit comprising three transmon qubits whose dynamics mirror those of interacting bosonic particles on a lattice, described by the Bose-Hubbard Hamiltonian. We verify the predictions of the Bose-Hubbard model for this system spectroscopically and then use time-domain measurements to study the decoherence processes affecting the qubits. Using a Raman process, we engineer artificial decay dynamics in the system which allow us to prepare and stabilize otherwise inaccessible states of the transmon array./nThe second experimental demonstration concerns topological quantum matter. Certain quantum systems are characterized by quantities known as topological invariants, which are robust to local perturbations. These topological invariants are challenging to measure in naturally-occurring systems. We engineer an artificial system, comprising a transmon qubit coupled to a high-Q cavity, capable of undergoing a protocol known as the quantum walk, which also exhibits topological invariants. By using particular non-classical state of the cavity, we modify the quantum walk protocol to make the topological invariant directly accessible./nFinally, we implement a hybrid quantum-classical algorithm—known as the variational quantum eigensolver—in a two-transmon quantum processor. As a proof of principle demonstration, we compute the ground-state and low-lying excited state energies of the hydrogen molecule as a function of nuclear separation. We show that an extension of the basic algorithm, known as the quantum subspace expansion, allows for the mitigation of errors caused by decoherence processes affecting the quantum processor.

Advisor: Siddiqi, Irfan
Tensegrity Spines for Quadruped Robots

Robots that are designed for NASA's missions to foreign planets, as with disaster relief efforts on earth, face tough challenges with harsh environments and locomotion over extreme terrain. Soft-bodied robots could address many of these challenges by conforming and adapting to their environments. This dissertation presents the modeling, design, and control of a set of soft and flexible robotic spines that assist quadruped robots in their locomotion over extreme terrain. These spines are tensegrity systems, consisting of rigid bodies held together in a network of flexible cables, used as a practical method of producing soft behavior./nFirst, the geometry and possible movements of these spines are discussed. Next, the inverse statics problem is solved for these spines, in order to calculate the tensions of the cables which control the spine's vertebrae. The resulting inverse statics optimization algorithm is tested in a hardware experiment, demonstrating pseudo-static open-loop positioning of the spine. Using this model, a design of a quadruped robot with a tensegrity spine is proposed and prototyped. Simulations show that this quadruped robot's tensegrity spine can lift and position its feet, as a way to assist with locomotion and balance. Hardware experiments validate the simulation's motions of the robot's spine and feet./nThen, control systems are investigated for these tensegrity spines. A set of closed-loop controllers, which use model-predictive control (MPC) in combination with the inverse statics algorithm, are proposed and simulated against dynamics models of the spine. Two different MPC formulations are used, both of which show low-error tracking in simulation./nFinally, given the ongoing challenges with MPC, an energy-based stability criterion is derived for a class of high-dimensional, nonlinear, possibly hybrid robotic systems./nThese systems, termed `statically conservative', include networks of cables in tension, similar to tensegrity spines. The stability criterion is applied to these cable networks, giving conditions for stabilizing controllers. An example controller is proposed for a cable-driven robot with slack cables. Simulations of this system and its controller to validate the stability proof. These control approaches show promise for future hardware implementation of walking locomotion in quadruped robots with tensegrity spines.

Advisor: Agogino, Alice M
Local to Global and Back Again: A Comparison of National Special Education Policies to a World Model

The United Nations Convention on the Rights of Persons with Disabilities (CRPD, 2006), Article 24, stipulates that children with disabilities should have access to and benefit from public education. As of this writing, 177 countries have ratified the convention (United Nations Department of Economic and Social Affairs, 2018). However, little is known about whether the extent or features of national policies lead to greater identification and enrollment of children with disabilities (CWD) in formal schools. This study will describe one possible mechanism for the diffusion of public education for CWD through national or regional legislation for special education by countries participating in the CRPD (2006). The analysis will compare cross-country enrollment rates for CWD with prominent topical themes in country or regional legislation using structural topic modeling methods. Additionally, the analysis will examine correlations between enrollment rates, prominent topics, and meta-data (other relevant variables) identified as significant in the literature on policy diffusion. The data presented here may inform the special education field about the extent and effects of the global diffusion of education policies for CWD. The analysis may also extend world culture theory in sociology, detailing the use of international documents to influence policy language around the ideals of education for CWD.

Advisor: Fuller, Bruce
Evaluating New Copyright Reforms in the Mandarin Music Market: Assessing How Collective Management and the Licensing Systems Afford Economic Incentives for Artists

China’s music copyright collecting society (the Music Copyright Society of China (MCSC)) and its new music platforms (e.g. Tencent, NetEase, Alibaba’s Xiami Music, Baidu Music and QQ Music), find points of commonality through constructing more efficient and profitable systems, so as to generate more users and greater income. These new perspectives can provide artists in the Mandarin music market with a more flexible and profitable pathway to construct their licensing infrastructure. It can also be observed how technology facilitates this breakthrough./nIn the relevant scholarly literature, articles on music licensing have mostly focused on music licensing issues within a single jurisdiction, or new approaches to music licensing issues discovered by concentrating on international norms./nThis research advocates the notion that the new licensing models and regulations in the U.S. and Europe deserve closer examination. By undertaking a comparison of the various copyright regulations, cases and statistics, this research aims to contribute to academic science by extracting frameworks and solutions from the U.S. and European licensing models, and examining them in context of the Mandarin music market.

Advisor: Merges, Robert P.
Interactive Prediction and Planning for Autonomous Driving: from Algorithms to Fundamental Aspects

Inevitably, autonomous vehicles need to interact with other road participants in a variety of highly complex or critical driving scenarios. It is still an extremely challenging task even for the forefront companies or institutes to enable autonomous vehicles to interactively predict the behavior of others, and plan safe and high-quality motions accordingly. The major obstacles are not just originated from prediction and planning algorithms with insufficient performances. Several fundamental problems in the fields of interactive prediction and planning still remain open, such as formulation, representation and evaluation of interactive prediction methods, motion dataset with densely interactive driving behavior, as well as interface of interactive prediction and planning algorithms./nThe aforementioned fundamental aspects of interactive prediction and planning are addressed in this dissertation along with various kinds of algorithms. First, generic environmental representation for various scenarios with topological decomposition is constructed, and a corresponding planning algorithm is designed by combining graph search and optimization. Hard constraints in optimization-based planners are also incorporated into the training loss of imitation learning so that the policy net can generate safe and feasible motions in highly constrained scenarios. Unified problem formulation and motion representation are designed for different paradigms of interactive predictors such as planning-based prediction (inverse reinforcement learning), as well as probabilistic graphical models (hidden Markov model) and deep neural networks (mixture density network), which are utilized for the prediction/planning interface design and prediction benchmark. A framework combing decision network and graph-search/optimization/sample-based planner is proposed to achieve a driving strategy which is defensive to potential violations of others, but not overly conservatively to threats of low probabilities. Such driving strategy is achieved via experiments based on the aforementioned interactive prediction and planning algorithms with proper interface designed. These predictors are also evaluated from closed loop perspective considering planning fatality when using the prediction results instead of pure data approximation metrics. Finally, INTERACTION (INTERnational, Adversarial and Cooperative moTION) dataset with highly interactive driving scenarios and behavior from international locations is constructed with interaction density metric defined to compare different datasets. The dataset has been utilized for various behavior-related research areas such as prediction, planning, imitation learning and behavior modeling, and is inspiring new research fields such as representation learning, interaction extraction and scenario generation.

Advisor: Tomizuka, Masayoshi
Amor en Aztlán: Music, Movement, Performance, and Power in the Conjunto Dancehalls of the Texas—Mexico Borderlands

This dissertation examines the Texas Mexican musical genre known as conjunto and its concomitant social world. In this work I situate conjunto within a broader context of Mexican American cultural production, Texas Mexican popular music, and the shared histories of the U.S.-Mexico borderlands. As a social history, the dissertation traces the development of the genre and its practitioners across the twentieth century to the present. I examine interactions of power; expressions of identity; and constructions of race, class, and gender through movement (dance), performance (instrumentation and playing), and place (the dancehall or nite club) within and around San Antonio and South Texas. I argue that conjunto is an embodiment of Xicanx thought and knowledge, an everyday act of resistance and reaffirmation.

Advisor: Perez, Laura E
A Question of Design: The Investigation of Space and Structure in Hawaiian Kauhale

Remnants of past communities dot the landscape in southeast Maui, preserving the memory of the people that once lived along the southern slopes of Haleakalā. The remaining agricultural field systems, foundations of houses (hale), and the materials within preserve fragments of daily life that speak to the construction of place and identity on this leeward landscape. This dissertation analyzes seven kauhale (house complexes) in Nu‘u, Kaupō, Maui ahupua‘a (political division of land) that were in use between the 16th and 18th centuries for the anthropological goal of discerning how the relationship between kānaka maoli (Native peoples) and the āina (land) shaped social practices in the community (defined as the ahupua‘a). The construction and use of kauhale were impacted by geographic location and social status (e.g. gender, class, and occupation). making house complexes an important entrypoint for exploring place-specific adaptations of larger social structures.

Advisor: Kirch, Patrick V
A Home Away From Home: Recreation Centers and Black Community Development in the Bay Area, 1920-1960

In this dissertation, I argue that recreation centers played a pivotal role in the black community as sites of racial uplift, political activism, and as a conduit to public service agencies in the San Francisco Bay Area. My work links literature in urban history and African American history to demonstrate the unique circumstances the city landscape presented to African Americans and how they not only responded to those circumstances, but also how they shaped them, especially during World War II. In particular, the project examines the ways in which black-founded and black-directed recreation centers acted as an affirmative alternative to the confrontations and humiliations that awaited them at segregated recreational venues as well as public amusements and accommodations./nIn addition, this work explores why, how, and with what consequences these black recreation centers contributed to the changing geography of the Bay Area. Creating their own agendas separate from white reformers and city officials, who believed structured recreation was a way to control and exercise surveillance over delinquent youth, black leaders viewed these recreational spaces as opportunities to provide community members with the necessary tools to challenge the racism they faced at work, school, and in the streets. The most significant scholarly intervention of this historical study is to center the lived experiences of African Americans: to explore thoroughly and critically how these recreational institutions operated in their lives and communities. Put another way, this dissertation uses the experiences of African Americans, both developing and participating in these institutions, as a lens to investigate and illuminate the broader concerns of African Americans living in the Bay Area from 1920 to 1960.

Advisor: Martin, Waldo E
Memorialization and the Limits of Reconciliation: Transnational Memory Circuits of the Korean War

The Korean War, as a “hot war” within the Cold War period with participation by 21 member nations of the UN and the People’s Republic of China, and also an unresolved civil war between South Korea and North Korea, is characterized by still-present animosities, which play out in contemporary politics in the Asia-Pacific region, as well as for the U.S. Furthermore, memoryscapes of the Korean War continue to be shaped and reshaped in the present. My dissertation examines built spaces and cultural texts of Korean War memorialization, focusing specifically on films, museums, and memorials in South Korea and the U.S. in the “post-Cold War” conjuncture. It focuses specifically on the theme of reconciliation to ask, how do Korean War memorial texts and spaces attempt to reconcile an unfinished Cold War conflict in a post-Cold War world?/nI trace the theme of reconciliation in multiple ways – first, I utilize the common definition of reconciliation as an act of bringing issues to an agreement. For example, how do memorial texts and built spaces suture histories and memories into coherent or cohering narratives? Furthermore, I examine reconciliation as a specific affective theme in South Korean popular and national cultures, particularly through the imagined reunification between South Korea and North Korea, and/or separated family members stuck on opposite sides of the DMZ border as well as divided ideologically. Lastly, I examine reconciliation as a conceptual theme underlying memorialization of the Korean War in relation to Cold War memory and history – what is the relationship between memorialization and history, particularly as memorial and national texts attempt to make sense of Korean War history (as a technically unfinished war) with Cold War history (as a “finished” event)?/nMemorials and national/popular memory of the Korean War are thus necessarily changing or constantly being amended in flux with changing presidential administrations as well as in response to veterans or civic groups in both the U.S. and South Korea. In studying the memory of war, it is impossible to ignore the ways in which memory and memorial discourses travel across geographic space in reference to each other, whether intentional or not. Drawing from the rich genealogy of Asian American cultural critique, this dissertation argues that critical Asian American memorial studies as methodology to study memorialization can bring out transnational narratives and allows for the multiple subjectivities of museum/memorial visitors and film viewers to enable readings beyond existing Cold War frameworks and narratives in both South Korea and the U.S. Through conducing a transnational study of Korean War memory, this dissertation rethinks the Korean War as “forgotten war” or as the benchmark for showcasing South Korean developmentalism (“forgotten victory” discourse), but rather the nuances in differential layers of forgettings and rememberings that constitute Korean War memoryscapes in the “post-Cold War” period.

Advisor: Kim, Elaine H.