VictorJuiz/thesis huggingface dataset:
Learning Grounded Pragmatic Communication

This dissertation shows how language generation and interpretation across varied grounded domains can be improved through pragmatic inference: explicitly reasoning about the actions and intents of the people that the systems interact with. We train neural generation (speaker) and interpretation (listener) models which ground language into a world context, then layer a pragmatic inference procedure on top of these models. This pragmatic procedure predicts how human listeners will interpret text generated by the models and reasons counterfactually about why human speakers produced the text they did./nWe begin by showing that explicit pragmatic inference aids in correctly generating and following natural language for complex, sequential grounded instruction tasks. Evaluation of language generation and interpretation shows that pragmatic inference improves state-of-the-art listener models (at correctly interpreting human instructions) and speaker models (at producing instructions correctly interpreted by humans)./nNext, we describe extensions of this approach to vision-and-language navigation. We combine visually-grounded listener and speaker models, using the speaker model to synthesize new instructions for data augmentation in addition to evaluating candidate action sequences in pragmatic inference. Both models are supported by a panoramic action space that reflects the granularity of human-generated instructions. Experiments show that all three components of this approach---speaker-driven data augmentation, pragmatic inference and the panoramic action space---dramatically improve the performance of a baseline instruction follower, more than doubling the success rate over the best existing approach on a standard benchmark./nFinally, we present a grounded neural dialogue model that successfully collaborates with people in a partially-observable reference game. We focus on a setting where two agents each observe an overlapping part of a world context and need to identify and agree on some object they share. Therefore, the agents should pool their information and communicate pragmatically to solve the task. Our dialogue agent accurately grounds referents from the partner's utterances using a structured reference resolver, conditions on these referents using a recurrent memory, and uses a pragmatic generation procedure to ensure the partner can resolve the references the agent produces.

Advisor: Klein, Dan
Essays on Health Insurance Policy and Inequality in the United States

In this dissertation, I study how health insurance products are priced, and how consumers select health insurance products in the United States. The first chapter focuses on selection and choice at the broader level of health care markets, comparing Medicaid, employer sponsored insurance, and insurance exchanges. I study cross-market adverse selection in the context of the Affordable Care Act, which simultaneously expanded Medicaid while creating health insurance exchanges. Using state decisions to expand Medicaid and variation in federal reinsurance payments as identification, I find that Medicaid expansion reduced prices on individual health insurance exchanges by an average of $504 (9.7%) per person, per year. These price reductions on the individual market represent an indirect benefit of Medicaid expansion that is equal to 9% of the total costs of expansion, and increased enrollment of higher income individuals (above 400% of the Federal Poverty Level) on the individual market by 10%. I then estimate a structural demand model with rich individual heterogeneity across consumers using a combination of public and administrative datasets. This model shows that, while the 2014 Medicaid expansion reduced prices in private markets, further expansions to Medicaid would have the opposite effect because they target a healthier population./nIn the second chapter, we study differentiation across health insurance providers in the market for employer-sponsored health insurers. Using rich administrative data and firm and employer changes between plans we recover the causal contribution of private insurers/brands to health care spending overall, prices and quantities as well as granular measures of health care utilization. We find clear variation in total spending between private health insurers. E.g. moving from United Health Care to Regence causally increases spending by an average of 40%. We find that changes in spending between insurers are largely explained by differences in extensive margin measures of quantity of care consumed. We find much less differentiation across insurers in terms of bargaining over provider prices or utilization of high versus low value care.

Advisor: Handel, Ben
Transition-Metal Catalyzed Asymmetric Fluoroalkylation and C–F Activation

The following dissertation discusses the development, study, and applications of transition-metal-catalyzed substitution reactions to provide enantioenriched tertiary alkyl fluorides. These reactions constitute some of the first enantioselective substitutions of fluoroalkenes and the first examples of the enantioselective desymmetrization of difluoromethylene groups. Several of these reactions define new strategies for the controlled activation of C–F bonds. Mechanistic studies have revealed several unique aspects of the stability, reactivity, and stereochemistry of fluorinated organometallic intermediates, revealed the turnover-limiting and enantiodetermining steps in Ir-catalyzed C–F activation reactions, and highlighted the powerful effects of bimetallic cooperation in C–F activation reactions. In the final chapter, we discuss the contrathermodynamic isomerization of olefins by a tandem process.

Advisor: Hartwig, John F
The Infrastructures of Finance: The London Stock Exchange and the Politics of Market Structure in Modern Britain, 1801-1914

Between 1801, when the London Stock Exchange was re-constituted as new, formal entity, and 1914, when WWI brought the first age of globalization to a close, financial capitalism expanded dramatically. At the beginning of the century there were only 6 formal stock exchanges in the world. By the end of it, there were almost 90. Financial markets were linked together by global telecommunications networks that allowed capital to travel at faster speeds over greater distances. Finance assumed the commanding heights not just of the economy, but also of imperial policy, as states aggressively looked to expand their informal empires through the power of the financial sector. But rather than focusing on the subjects that typically populate the financial histories of this era—the great banking families of Baring and Rothschild who floated sovereign loans and bailed out troubled states, the stockbrokers who jostled for space and profits on trading floors throughout the world, or the ebbs and flows of capital and asset prices—this dissertation tells the story of the men, women, and things who made the actions of financiers possible. Whether it was the human infrastructures of the waiters, porters, and telegraph boys who facilitated the communications between financiers, the clerks, journalists, and statisticians who provided the information and data financiers needed to make investment decisions, or the material infrastructures of telegraphs, ticker tapes, telephones, electrical circuits, batteries, and cables through which those communications and data travelled, the act of exchange was always at the mercy of the infrastructures that underpinned it. Telling a financial history that focuses on infrastructures rather than the act of exchange, changes our understanding of financial power in two ways. First, this dissertation shows how certain, powerful institutions and firms, like the London Stock Exchange, gradually began to exercise infrastructural power over states and societies by co-opting the underlying infrastructures upon which financial exchange depended. The rise of financial capitalism depended not on a lifting out or abstraction of previously personal and traditional modes of exchange but was far more about the ways finance seized hold of mundane infrastructures—like the ostensibly public infrastructure of the telegraph—and co-opted them towards financialized logics. Second, an infrastructural history of finance also restores agency to our understanding of financial history, that all too often relies on myths of the power of great men or of efficient markets. Instead, this dissertation shows how even the smallest and seemingly least powerful actors could have outsized effects on the financial system through their control over the mechanics and operations of the infrastructures of finance.

Advisor: Laqueur, Thomas W.
Photonic Heat Engines at Thermodynamic Limits

In thermophotovoltaic energy conversion, photovoltaic cells convert thermal radiation from a local emitter to electricity. The key is to find a way to exploit the great majority of low-energy thermal photons that would otherwise be unusable in a photovoltaic system. A highly reflective rear mirror can serendipitously boost the voltage, and regenerate the low-energy photons. Based on this concept, we demonstrate a 29.1% heat-to-electricity power conversion efficiency for thermophotovoltaics. We identify broadband mirrors as a major parameter to achieve thermophotovoltaic efficiency>50%. We show the challenges towards designing broadband mirrors and demonstrate an electromagnetic inverse-design approach based on Fresnel propagation. Finally, we demonstrate mirrors with >99% reflectivity over 3-octaves of frequency bandwidth. This new class of mirrors can make photonic heat engines based on thermophotovoltaics competitive with internal combustion engines. Additionally, for record-breaking solar cells the external luminescence efficiency is decisive in determining the open-circuit voltage, Voc=Voc-ideal -kT|ln{ext}|. External luminescence efficiency, ext, has produced all the record solar cells in the past 10 years. On the other hand, for poor luminescent materials, the external luminescence is far less decisive than the internal luminescence efficiency, int.. Most solar cells, including the important case of Silicon, luminesce very poorly. We express the open circuit voltage in terms of int, that provides the correct Voc for poor luminescent materials. We show how the internal luminescence efficiency affects the open-circuit voltage. We identify the minimum internal luminescence needed to further improve open-circuit voltage through good external luminescence.

Advisor: Yablonovitch, Eli
Nanoelectromechanical Switch Design and Implementation in Back-End-of-Line Technology

The emergence of the Internet of Things (IoT) has made energy efficiency a key requirement for integrated electronic systems. Nanoelectromechanical (NEM) switches have the ideal characteristics of zero OFF-state leakage and small subthreshold swing, making them promising candidates for ultra-low-power digital computing applications. IoT has also motivated the development of new computing architectures that are more energy-efficient than the classic von Neumann architecture. An “in-memory computing” architecture avoids the need for data communication between separate processing and memory units, and hence achieves more energy-efficient operation. For such a computing architecture, it is desirable to have compact non-volatile (NV) memory cells that can be programmed and read with very low energy./nUtilization of back-end-of-line (BEOL) metallic interconnect layers to implement non-volatile NEM switches is an attractive approach for monolithic integration with CMOS transistors, which can enable enhanced chip functionality with relatively low incremental manufacturing cost. This dissertation addresses the fabrication challenges for realizing BEOL NEM switches and demonstrates their suitability for implementation of new computing architectures. Etch recipes and cleaning techniques are developed and optimized to successfully achieve BEOL NEM switches using standard 65nm and 16nm CMOS manufacturing processes, for the first time./nThis dissertation also presents a new, vertically oriented NEM switch design implemented using multiple BEOL layers to achieve a more compact footprint. Design trade-offs are investigated, and design constraints for reliable and energy-efficient operation are discussed. A design optimization framework is presented to minimize the energy-delay product associated with the programming operation of a NEM switch./nPrototype reconfigurable hybrid CMOS-NEM circuits comprising arrays of BEOL NV-NEM switches are experimentally demonstrated for the first time, showing their promise for compact, energy-efficient and fast memory-based data searching and look-up table operation./nScaling of NV-NEM switches to smaller dimensions is projected to lower their operating voltage, in order to be compatible with standard CMOS transistors, as well as to improve their energy-delay performance. The read/ write energy and read delay of the vertically oriented NV-NEM switch are projected to compare very favorably against the same performance parameters of other emerging embedded NV memory technologies.

Advisor: Liu, Tsu-Jae
Synthesis of Topologically Complex Natural Products: Total Synthesis of Arcutinidine and Progress Toward Septosone A

This dissertation details our approaches toward the topologically complex natural products arcutinidine and septosone A. Chapter 1 is a comprehensive overview of the previous approaches toward the arcutane natural product scaffold by other groups. Particular attention is paid to the choices made by others in their retrosyntheses and how they affected the forward syntheses. This section also includes the proposals for the biosynthetic origin of the arcutane alkaloids from the hetidine-type diterpenoid alkaloids./nChapter 2 describes our attempts to perform a contra-biosynthetic rearrangement from an arcutane-type to a hetidine-type skeleton in a model system. Although we were unsuccessful in effecting the desired transformation, it provided some interesting reactivity. This chapter also details the completion of the total synthesis of the diterpenoid alkaloid arcutinidine./nChapter 3 gives an introduction to septosone A and related meroterpenoid natural products, specifically the dysifragilones and the dactyloquinones. It details the biological activity of septosone A and presents an in depth look into the biological pathway(s) responsible for the bioactivity. This chapter also describes the proposed biosynthetic origin of the septosones and related congeners. The syntheses of less complex tricyclic and tetracyclic meroterpenoids is discussed to provide context for the choices made in our retrosynthesis./nChapter 4 details our synthetic efforts toward septosone A. After two unsuccessful approaches, success has been achieved toward the completion of four of the five rings in septosone A. Utilizing a Wieland–Miescher ketone derivative that was coupled to a functionalized phenyl ring, an intramolecular Heck cyclization forged the central five-membered ring. Investigations are ongoing to complete the septosone A scaffold. Although unanticipated at the onset, our studies provide access to the dysiherbol, dysifragilone, and dysidavarone meroterpenoid scaffolds.

Advisor: Sarpong, Richmond
Unsettled Truths: Law, Culture, and Credibility in Affirmative Asylum Claims 1989-2018

Sitting at the heart of determining eligibility for asylum, and therefore the most crucial part of a claim that for many means the difference between life and death, the importance of demonstrating credibility cannot be overstated. Yet credibility does not lend itself to straightforward quantification or measurement, and those measures on which we do rely are imperfect and highly subjective. This dissertation asks how the evolution of cultural ideas about credibility shape the form of asylum claims, and in light of this process, how asylum-seekers navigate competing demands to make credible claims of persecution and fear. I argue that by analyzing asylum narratives we can observe the nature and function of credibility both in the specific institutional context of adjudicating claims, and in the broader political and cultural contexts of defining and measuring truth. To understand how asylum seekers legally and discursively construct credibility I ask: (1) How do asylum seekers construct credibility in their written and oral narratives? (2) How are claims shaped by the institutional environment in which decisions are made and the evolution of cultural ideas about credibility? (3) How are the construction and contestation of credibility informed by the nature of the claimant’s identity and experience? and, lastly (4) How and why does the construction and contestation of credibility change over time?

Advisor: Edelman, Lauren B
Total Syntheses of Pentacyclic Ambiguine Natural Products and Studies toward the Total Syntheses of Prenylated Indole Alkaloids: Versicamides and Carneamides

The medicinally relevant indole structure is frequently encountered in drug candidates and naturally occurring molecules. These indole alkaloids exhibit diverse molecular structures and exert exciting biological functions that are useful to human and plant health. Many of these important natural products lack effective means for their chemical synthesis, therefore limiting access. My dissertation focuses on the study of new strategies to synthesize indole alkaloids./nThe first chapter describes my efforts at functionalizing the C2 position of brevianamide F, which is proposed to be a common intermediate in the unified synthesis of prenylated indole alkaloids, versicamide and carneamide natural products. Several synthetic routes to directly functionalize the indole C2 position of brevianamide F were investigated, and a C2-borylated brevianamide was prepared. Advancing this intermediate to reverse-prenylated brevianamide F, and optimizing its diborylation will be key to achieving the proposed syntheses./nIn Chapter 2, the first synthesis of a pentacyclic ambiguine (ambiguine P) is discussed. As part of a team, we developed a strategy that takes advantage of sequential, robust, alkylative functionalizations of indole, leading to the rapid construction of the ambiguine core structure. Key to the success of the synthesis is the use of a Nicholas reaction to alkylate at C2, crafting a fused seven-membered ring that is characteristic of the pentacyclic ambiguines, as well as the use of an amide-directed functionalization at C12 to set a requisite quaternary center. A versatile late-stage intermediate was prepared that may be applicable to the synthesis of the other pentacyclic ambiguines. The first total synthesis of ambiguine P was completed in 21 steps from carvone via a late-stage C–H oxidation./nChapter 3 describes the use of the synthesis strategy and knowledge acquired from the studies described in Chapter 2 to synthesize related ambiguines of higher oxygenation levels. From the advanced intermediate prepared in the synthesis of ambiguine P and described in Chapter 2, various synthetic sequences are examined to access ambiguines L, I, N, and J. Various strategies have been explored to install the C10 hydroxy group that is common to most members of the ambiguine family. Late-stage oxidation of the pentacyclic scaffold has proven to be a challenge due to the presence of the oxidation-sensitive indole moiety. Ultimately, the desired oxidation state at the C10 position was achieved through formation of an alkene, from which the seven-membered E ring of the scaffold is functionalized. The resulting C25 and C26 oxidation products map onto ambiguines N and O, respectively, thereby paving way for their completion.

Advisor: Sarpong, Richmond
Forgetting to Remember: Theorizing the Role of the Forgotten in the Production of the Hebrew Bible

In this dissertation, I examine the Hebrew Bible as a cultural product, analyzing the diachronic text formation practices therein as acts of cultural memory./nWhereas approaches to cultural memory tend to focus on continuity, I turn my attention to forgetting, arguing for the forgotten as a site of fecundity—while remembering makes texts present across time, forgetting is the mechanism that allows meaning to change and multiplicities to converge, forming cultural text into a portable and durable cultural symbols. In this project, I center the scribes writing into the text as agents within the tradition who perform this kind of memory work as they redact, add to, or insert text into their inherited literatures./nThis dissertation is made of three case studies that address selected pericopes from three of the main literary genres in the Hebrew Bible: pentateuchal law (Exod 34:11-17), prophetic poetry (Isa 2), and historical narrative 1 Sam 13-15). Each study integrates an eclectic methodology, drawing from the methods traditional to biblical studies (text-criticism, redaction-criticism, philology, etc.) along with theories of cultural memory and intertextuality. I begin each case study by making an argument concerning the text’s composition history, and I proceed to analyze the secondary layer as an act of cultural memory that brings the text forward in time, but which also changes the text and its potentialities moving forward. This change, I argue, is part of what allows syntheses between cultural texts to converge into cultural symbols, which can be described as extra-textual hermeneutical assumptions by which readers approach the text. Those which I suggest are active in these case studies are Canon, Isaiah as Seer, and Divine History.

Advisor: Hendel, Ronald S
High-performance FMCW LiDAR with MEMS Optical Beam Scanner

3D imaging sensors are crucial components for modern intelligent machines to detect and perceive the surrounding world. Among different 3D sensing technologies, light detection and ranging (LiDAR) systems offer high distance and lateral resolutions and are able to work in darkness, therefore have applications that span several industries and markets, from metrology, robotic control, autonomous vehicles, to consumer electronics.Compared with other LiDAR principles such as the pulsed time-of-flight, frequency-modulated continuous-wave (FMCW) LiDAR can achieve high-resolution distance and velocity measurements without fast electronics or high peak optical power thanks to the coherent detection advantages, but it typically requires narrow-linewidth lasers with complex feedback circuits to generate linear chirps. In this dissertation, we will summarize our research on linearizing the laser chirp by iterative learning pre-distortion of the drive waveform and compensating for the laser phase noise in post-processing. With these two methods, high-performance FMCW LiDAR can be achieved with commercial semiconductor lasers and a simple setup. Besides the laser ranging system, the optical beam scanner is an essential component in scanning LiDAR. An integrated optical beam scanner with fast speed, large field-of-view, high resolution, and low power consumption is an essential element for solid-state LiDAR. In this dissertation, we will introduce two integrated beam scanner architectures based on micro-electromechanical system (MEMS), (1) grating-based 2D optical phased array (OPA), and (2) 2D focal plane switch array (FPSA) with MEMS optical switches. We will discuss their operation principles as well as the advantages and challenges, and we will show the design, fabrication, and characterization of a 160×160-element OPA, a 20×20-element FPSA, and a 128×128-element FPSA. We will also demonstrate the implementation of the 128×128-element FPSA beam scanner on an FMCW LiDAR for 3D imaging. We believe these highly scalable integrated beam scanners are very promising candidates for chip-scale solid-state LiDAR sensors.

Advisor: Wu, Ming C