VictorJuiz/thesis huggingface dataset:
Measuring the fine structure constant with a state-of-the-art atom interferometer

Measurements of the fine-structure constant α require methods from across subfields and are thus powerful tests of the consistency of theory and experiment in physics. Using the recoil frequency of Cesium-133 atoms in a matter-wave interferometer, we recorded the most accurate measurement of the fine-structure constant to date: α = 1/137.035999046(27) at 2.0 × 10−10 accuracy. Using multiphoton interactions (Bragg diffraction and Bloch oscilla- tions), we demonstrate the largest phase (12 million radians) of any Ramsey-Bord ́e interfer- ometer and control systematic effects at a level of 0.12 part per billion. Comparison with Penning trap measurements of the electron gyromagnetic anomaly ge − 2 via the Standard Model of particle physics is now limited by the uncertainty in ge − 2; a 2.5σ tension rejects dark photons as the reason for the unexplained part of the muon’s magnetic moment at a 99% confidence level. Implications for dark-sector candidates and electron substructure may be a sign of physics beyond the Standard Model that warrants further investigation.

Advisor: Müller, Holger
New RF Transmitter Techniques for RFID, Cellular, and mmW Applications

Reader/Transmitter (Tx) designs for inductive-power-transfer (IPT) systems have to power up the tag and must be able to listen to it. The low power transfer efficiency (PTE) and the high Tx-to-Rx interference are the main challenges when a tiny tag is involved. To improve PTE, an analytical approach for optimizing the Tx coil and the miniature rectenna has been developed. The equation-based approach optimizes the IPT design rapidly, locating the optimal IPT frequency and the coil geometries. An optimized 2.2-mm IPT uses a RF power of 33.1 dBm, and the designed 0.01mm2 CMOS rectenna harvests a dc power of 0.1 mW. To suppress the Tx-to-Rx leakage, a new T/Rx architecture has been invented with a two-tone Tx that simultaneously charges the tag and excites a third-order intermodulation (IM3) frequency from the tag nonlinearity. The IM3 tone is modulated by the tag data and transmitted back to the reader Rx via the same coupled-coils. The Tx/Rx frequency separation allows significant filtering on the Tx-to-Rx leakage. This technique was adopted in IPT systems and far-field systems with a custom-designed tag and even demonstrated with a commercial UHF Gen2 tag. Multi-tone Tx has also been studied for further performance improvement./nThe other key application of RF transmitters is cellular communication. We have fabricated an all-digital CMOS Tx core on three interposers with high output power, >50% efficiency, and a collective bandwidth from 0.4 to 4 GHz. To further achieve frequency reconfiguration with a single package, a band-selecting interposer was designed to combine three identical CMOS Tx cores. The band selection is carried out by reconfiguring the switching devices in the CMOS PAs. Peak power higher than 23 dBm and efficiency better than 25\% are achieved from 0.4 to 4 GHz, by rotating the three sub-Txs. Finally, an E-band OOK-QPSK Tx element in 28nm bulk CMOS is presented. The Tx element is a suitable building block for digitally-modulated phased arrays and high-speed communications. Employing the Tx elements, the implemented Watt-level-EIRP mmW digital array demonstrates good efficiency and the capability of synthesizing a pattern null at a given direction. The leakage-suppression technique exploits the combination redundancy as the array synthesizes the desired spatial symbols, so the conventional high-resolution elements are not required.

Advisor: Niknejad, Ali M
Architecture on the Ground: Design and Contestation in West Bank Settlements, 1967 to the Present

This dissertation is an architectural history of West Bank settlements. Since 1967, when it captured the West Bank from Jordan in the Six-Day War, Israel has overseen the construction of hundreds of settlements. Though they began as an esoteric project, mainly associated with a small group of messianic Israelis, today, settlements house more than 430,000 Jewish Israelis. Built outside the recognized borders of Israel and against the opposition of the native Palestinian population, settlements have become one of the most contested housing projects in Israel and the world./nScholars of the built environment have often theorized West Bank settlements as a paradigmatic case of the militarization of architecture. Analyzing aerial views and statements made by individual politicians, they have argued that settlements function as war machinery. That argument is coupled by an assumption that settlements are of uniform design. As a result, existing scholarship has overlooked the fact that a heterogeneous landscape of settlement types and housing models—ranging from trailer homes and kibbutz houses, to suburban tract homes and multistoried apartment buildings—has come to form the settler movement over the last five decades. This heterogeneity defies easy categorizations and demands reconsideration of the political uses of architecture in the region./nArchitecture on the Ground studies the intricate design debates that accompanied the construction of settlements. It shifts the focus away from high-profile individuals to explore how architects, amateur archeologists, real estate developers, and disparate groups of settlers, ranging from religious Zionists to bohemian artists and ultra-Orthodox wives, played a pivotal role in the design and construction of settlements. It identifies five successive settlement patterns that have emerged over the fifty years Israel has occupied the West Bank. Each pattern emerged in response to different political moments, and is defined by characteristic building technologies, architectural forms, and practices of governance. In tracing the evolution of these five patterns, the dissertation seeks to model a new understanding of the relationship between architecture and politics—one founded on numerous contingencies and contradictions.

Advisor: Crawford, Margaret L
Synthesis and Transmission Electron Microscopy of Hexagonal Boron Nitride Nanostructures and Transition Metal Trichalcogenides in the Single Chain Limit

Hexagonal boron nitride (h-BN) nanomaterials exhibit peculiar morphologies and properties making them uniquely suitable for a host of applications. In this dissertation, I will introduce different approaches to synthesize various h-BN nanostructures, ranging from aerogels (three-dimensional porous network) and sheets (two-dimensional layers) to tubes (one-dimensional tubular material). The materials synthesis includes high-temperature carbothermic conversion (for h-BN aerogels and sheets) and extended pressure inductively-coupled (EPIC) nitrogen plasma (for h-BN nanotubes). The as-synthesized nanomaterials are characterized by different techniques with the emphasis on transmission electron microscopy (TEM), including both in-situ TEM and aberration-corrected TEM./nIn the second part of this dissertation, I focus on the discovery and structural characterization of the single chain limit of transition metal trichalcogenides (such as niobium triselenide, NbSe3), quasi one-dimensional van der Waals materials. By using carbon and boron nitride nanotube as nano-reactors, few-to-single chain NbSe3 can be isolated and stabilized. An aberration-corrected scanning/transmission electron microscopy (S/TEM) study shows that a single chain of NbSe3 exhibits structural torsional waves not found in bulk NbSe3 crystals. Density functional theory calculations reveal that charge transferred from nanotubes to the encapsulated single chain is responsible for the torsional instability. We term the phenomenon Charge-induced Torsional Wave (CTW). The study is extended to explore other transition metal trichalcogenides in the single chain limit, for example hafnium tritelluride, HfTe3. A newly segmented chain structure of HfTe3 is observed with potential non-trivial topological edge states.

Advisor: Zettl, Alex K.
Dubon, Oscar D.
Footage of Other Worlds: Unveiling the Dynamical Architecture of Young Exoplanetary Systems

This thesis focuses around using the Gemini Planet Imager (GPI), an instrument designed to directly-image exoplanets, as part of the GPI Exoplanet Survey (GPIES), a multi-year survey to image and characterize Jovian exoplanets orbiting at Solar System Scales (5-100~au). The first half of this thesis is on building the data analysis infrastructure for GPIES. I helped commission GPI by characterizing the ability to measure the position and flux of a star when it is placed behind an occulting mask specifically designed to suppress starlight. I also led the development of the automated data processing infrastructure for GPIES that handles all of the data storage, indexing, and processing. This data infrastructure has optimized survey execution, ensured uniform data products, and characterized instrument performance. In the second half of this thesis, I characterize two notable exoplanetary systems through precise astrometry and orbital analysis. I present improvements to astrometric data analysis that allow us to measure the position of $\beta$ Pic b to one milliarcsecond, the most precise astrometry of an exoplanet to date. I tighten constraints on its orbit, including timing a window in which circumplanetary material of this young exoplanet could be transiting the star. Lastly, I apply the same astrometry techniques to the HR 8799 system which harbors four Jovian exoplanets. I added dynamical stability priors on my orbit fits using an N-body integrator to find stable orbits in the system. Through this, I explore possible orbital resonances and place dynamical constraints on the masses of the planets.

Advisor: Graham, James R
Reputation: Content, Structure, and Trajectories

Utilizing a multi-method approach, in this dissertation I first examined how reputation forms over time and how reputation is transmitted and communicated in newly forming and existing social networks, which are primarily affiliative in nature. Next, I examined how reputation differs from related constructs such as status and trust, how one’s workplace reputation changes depending on specific behaviors (workplace transgressions, helpful behaviors, and thoughtful apologies), and how the trajectories of one’s reputation may not necessarily be consistent across people in the same context, but may differ depending on individual (and hierarchical) factors such as power and gender. Finally, I examined whether a network’s criteria or perception of “good” or “bad” reputation may differ depending on the reference context, how group consensus may differ in “good” versus “bad” reputations, and whether reputation relates to meaningful behaviors (performance) that are objectively observable. While many outstanding questions remain, taken together, the findings from the present research suggest that taking a more nuanced approach to the study of personal reputation is a crucial endeavor in order to better understand and predict important social and organizational outcomes.

Advisor: Keltner, Dacher
The genetic dissection of trait differences between species of Saccharomyces yeasts

Unbiased genetic dissection of widely observable phenotypic traits in the wild has/nlong been the goal of evolutionary geneticists. Mice, bacteria, rice and stickleback fishes/nhave historically been among the prime model organisms in the field. Here, we leverage/nthe recent surge of Saccharomyces yeast as a model genus in ecology and evolution to/nbegin answering questions about the genetic basis of ancient trait differences that have/nevolved between species, over long evolutionary time scales. Specifically, we want to/nknow what genetic mechanisms evolution has used to create new traits in the distant/npast, and what biological functions have been the focus of adaptation in the past. I/nintroduce the field and our questions of interest in the introductory Chapter 1. Next,/nChapter 2 delves deeper into the methods that have been used in the past to dissect/ninterspecies genetics, reviewing the literature and drawing general conclusions from/nwhat we have learned so far. In Chapter 3, we develop a new application of the/nreciprocal hemizygote test on a genome-wide scale to drill down to the single gene level/nand dissect the ability of S. cerevisiae to grow at high temperatures relative to other/nSaccharomyces species. We uncover a suite of housekeeping genes genetically/nresponsible for this derived phenotype and reveal a likely defect in cell division in S./nparadoxus as the culprit for cell death at high temperatures. Finally, in Chapter 4, we/ninvestigate two more species-specific differences: 1) resistance to the drug benomyl, a/nmicrotubule poison and 2) cold tolerance. Unexpectedly, while microtubules are the/nmolecular target of benomyl, it is the genes encoding water channels in the cell/nmembrane tha seem to be at the genetic root of these phenotypes. Our data begin to/nconnect the dots between the growth advantage in S. paradoxus in benomyl and at low/ntemperatures, relative to S. cerevisiae.

Advisor: Brem, Rachel
Taylor, John
Reengineering Elite Universities: Massive Open Online Courses and the Rise of Applied Science in American Higher Education

In the early 2000s a small handful of computer science and artificial intelligence researchers stitched together a platform to teach undergraduate computer science courses to tens of thousands of students simultaneously. These course, which became known as MOOCs (Massive Open Online Courses) instigated a wave of debate about the future of higher education, as well as a series of reforms at campuses across the country. This dissertation analyzes why this moment materialized in 2012, and how three elite universities at its center crafted organizational strategies in response. Using field theory and literature on academic capitalism, this dissertation will argue that MOOCs were a recent flashpoint in the increasing competition over leadership in academic computer science that is collapsing historical distinctions between arts and science universities and applied science schools. Part I analyzes the origins of the MOOC movement and charts changes in frames within the field using LDA topic modeling to show that online higher education moved from the periphery of the field of higher education to its center in the early 2010s. Part II leverages 45 primary interviews with leaders of three campuses most closely associated with the MOOC movement: Stanford, MIT, and Harvard. The analysis shows that Stanford administrators responded to unanticipated and provocative actions from entrepreneurial faculty members with the creation of a for-profit MOOC spin-off. While these actions conformed to theories of academic capitalism, the ultimate diffusion of MOOCs across the country led universities in Cambridge to reject profit as a central consideration in their strategic response, demonstrating that academic capitalism is not necessarily contagious. This dissertation argues that the tools of field theory provide insight into competition over the future of higher education which is contested along multiple simultaneous dimensions. Rather than competition over revenue, MOOCs represented intensification of overlap in the field of higher education between tradition arts and science based incumbents, and newly ascendant universities more closely associated with applied science and engineering.

Advisor: Fligstein, Neil
Statistical learning models of sensory processing and implications of biological constraints

Despite progress in understanding the organization and function of neural sensory systems, fundamental questions remain about how organisms convert visual, auditory, and other sensory input into useful representations to understand the world and guide behavior. An important and fruitful line of work models the brain as an unsupervised statistical learner, examining how a sensory system may optimize for efficient representation of the natural environment or for explicit representation of useful structure in that environment. This dissertation explores efficient coding and sparse coding models of the visual and auditory systems, the data these systems process, and how these models are affected by the constraints imposed by implementation in biological neural systems. First, I show that both natural images and natural sounds have statistical structure amenable to a sparse coding model but that the sparse structure of these two types of natural data also differ in interesting ways that may be relevant to extending the success of sparse coding in describing primary visual cortex (V1) to analogous regions of the auditory system. I also discuss how a related model may shed light on how the neurons in these sensory systems are organized in space based on coding for related stimulus properties. Second, I show that a sparse coding model with biological constraints requires its inputs to be whitened in order to learn sparse features using synapse-local learning rules. This observation provides a novel explanation for the separation of sparse coding and spatial decorrelation into, respectively, V1 simple cells and preceding areas including retina. Third and finally, I turn back to the auditory system and extend existing work on efficient coding in the cochlea to account for the requirement of causality, i.e., determining a code without knowledge of the future of a signal.

Advisor: DeWeese, Michael R
Evolution of technology and molecular sensor diversity in hyperpolarized xenon NMR of biological and oriented environments

The work in this dissertation revolves around the use and evolution of methods and molecular contrast agents for 129Xe nuclear magnetic resonance (NMR) techniques. A general overview of the scope of this work is provided in Chapter 1. An overview of the basic principles of magnetic resonance, the manipulation of magnetization in an NMR experiment, and the ways data from NMR experiments can be treated is provided in Chapter 2. Chapter 3 introduces hyperpolarized 129Xe NMR and describes the theoretical background and current applications of hyperpolarized xenon as they apply to biosensing, including the functionalization of xenon for molecular detection using macromolecular hosts and the principles of the hyperpolarized gas chemical exchange saturation transfer (hyperCEST) technique. Practical technical considerations involved with hyperpolarized 129Xe gas generation and delivery are provided in Chapter 4. The following three chapters each expound upon a completely different type of 129Xe sensor explored as a part of this thesis work: a cryptophane derivative (Chapter 5), a cucurbit[6]uril rotaxane (Chapter 6), and a targeted cucurbit[7]uril (Chapter7), while Chapter 8 introduces a new device that enables examination of hyperpolarized 129Xe in viscous and orienting media. Chapter 9 synthesizes all the components of previous chapters to explore the use of orienting media to further enhance molecular detection. This dissertation concludes in Chapter 10 with a clear direction for the next steps toward sensitive analysis of unprocessed biological samples with 129Xe NMR.

Advisor: Pines, Alexander
Methods and Systems for Understanding Large-Scale Internet Threats

Large-scale Internet attacks are pervasive. A broad spectrum of actors from organized gangs of criminals to nation-states exploit the modern, layered Internet to launch politically and economically motivated attacks. The impact of these attacks is vast, ranging from billions of users experiencing Internet censorship, to tens of millions of dollars lost annually to cybercrime. Developing effective and comprehensive defenses to these large scale threats requires systematic empirical measurement./nIn this dissertation we develop empirical measurement methods and systems for understanding politically and economically motivated Internet threats. Specifically, we examine the problems of Internet censorship and advertising abuse in-depth and at-scale. To understand censorship, we develop Augur and Iris, methods and accompanying systems that allow us to perform global, longitudinal measurement of Internet censorship at the TCP/IP and DNS layers of the network stack—without the use of volunteers. This work addresses a range of both technical and extra-technical challenges, at a scale and fidelity not previously achieved. In combating advertising abuse, we investigate and chronicle multiple facets of the ecosystem—from clickbots to large-scale botnets to advertising injection—using a variety of empirical methods. Our work ultimately identifies fundamental structural weak-points leverageable for defense, resulting in dismantling botnets, cleaning up ad networks, and protecting users.

Advisor: Paxson, Vern
Instrumenting Flexible Substrates for Clinical Diagnosis and Monitoring

Over the past decade, there has been rapidly growing interest in wearable and implantable devices for a wide range of biomedical applications. For many applications involving prolonged contact with the body, devices that are compliant and can comfortably conform to and move with the patient are highly preferred. These flexible substrates (i.e. clothing, bandages, meshes, catheters, etc) can be instrumented to measure various physiological markers, such as temperature, pH, and oxygenation levels, to better inform clinical care. In this dissertation, I will discuss two examples of sensors designed to interact with flexible substrates for clinical monitoring and diagnosis applications./nI will first present the development of an electronic bandage to objectively monitor the progression of wound healing in pressure ulcers and other chronic wounds. Chronic skin wounds affect millions of people each year and take billions of dollars to treat. Pressure ulcers are a type of chronic skin wound that can be especially painful for patients and are tricky to treat because current monitoring solutions are subjective. We have developed an impedance sensing tool to objectively monitor tissue health in wounds. An electrode array is printed onto a flexible, polymeric substrate to form a “smart” bandage. With this sensor array, we can measure impedance of the underlying tissue and extract information on tissue health (i.e. size of wounds and tissue types) to inform the clinical course of treatment./nIn the second half of the dissertation, I will discuss methods for instrumenting hernia mesh prosthetics to provide quantitative guidance to surgeons during hernia repair surgeries. Abdominal wall hernias are typically treated by suturing in a surgical mesh to cover and overlap the hernia defect. However, in 10-20% of patients, the hernia repair fails, resulting in recurrence of the hernia. 18% of these recurrences are attributed to mechanical failure of the mesh, often due to unequal stress distribution across the mesh surface resulting in high stress concentrations at the tissue-mesh interface. Strain across the mesh can be used as an indicator for how evenly stress is distributed across the surface of the mesh. I will discuss two methods, based on optical approach and magnetoelastic approaches, for instrumenting the hernia mesh prosthetic to measure the stress distribution during the surgical repair process and the postoperative healing period.

Advisor: Maharbiz, Michel M