VictorJuiz/thesis huggingface dataset:
A polarization sensitive bolometer array for the South Pole Telescope and measurements of Cosmic Microwave Background secondary anisotropies

Over the past several decades, measurements of the Cosmic Microwave Background (CMB) have been a major driving force in our understanding of cosmology. Measurements of the CMB on large angular scales places tight constraints on the parameters of the Lambda-CDM cosmological model. Measurements of the CMB at smaller angular scales constrains secondary anisotropies, such as the thermal and kinetic Sunyaev Zel'dovitch (tSZ and kSZ) effects, which constrain the structure of the universe at later times. The CMB is also polarized, and the polarization signal encodes information about both the inflationary era and late-time structure formation in our universe. In the first part of this dissertation, I introduce the CMB and discuss the measurements that have been made so far and what we can learn from them./nThe South Pole Telescope (SPT) is a 10 meter telescope that is dedicated to measuring the CMB down to small angular scales. So far, the SPT has housed two instruments, SPT-sz and SPT-pol. SPT-sz was sensitive to temperature and completed a 2540 square degree survey of the southern sky from 2008-2011. SPT-pol is a polarization sensitive camera that was deployed in 2012, and has been conducting a polarization survey since that time. These instruments both use photon-noise limited superconducting Transition Edge Sensors (TESes) in large numbers to obtain their high sensitivities. TES design and fabrication in large format arrays was critical to the success of these instruments. The second part of this dissertation focuses on the instrumentation of the SPT. I present the theory behind TES bolometer design with a focus on detector stability and optimal performance. Finally, I discuss the design and performance of the two instruments, with a focus on the detector development for the SPT-pol instrument./nIn the final part of this dissertation, I use the full 2540 square degree SPT-sz survey to measure the power spectrum from 1850 < l < 11000 at 90, 150, and 220 GHz and constrain small scale CMB anisotropies. We use a multifrequency cross-spectrum analysis to fit the data using a model that includes the lensed primary CMB, secondary CMB anisotropies (tSZ and kSZ effects), and foregrounds. The foreground power consists of a poisson component from radio sources, poisson and clustered components from dusty point sources, galactic cirrus, and tSZ-CIB correlations. These data represent the most sensitive measurement of the small angular scale CMB power spectrum to date. The data constrain the amplitude of the tSZ and kSZ signals, from which we can learn about late time structure and the epoch of reionization.

Advisor: Holzapfel, William L.
An Architecture for and Fast and General Data Processing on Large Clusters

The past few years have seen a major change in computing systems, as growing data volumes and stalling processor speeds require more and more applications to scale out to distributed systems. Today, a myriad data sources, from the Internet to business operations to scientific instruments, produce large and valuable data streams. However, the processing capabilities of single machines have not kept up with the size of data, making it harder and harder to put to use. As a result, a growing number of organizations---not just web companies, but traditional enterprises and research labs---need to scale out their most important computations to clusters of hundreds of machines./nAt the same time, the speed and sophistication required of data processing have grown. In addition to simple queries, complex algorithms like machine learning and graph analysis are becoming common in many domains. And in addition to batch processing, streaming analysis of new real-time data sources is required to let organizations take timely action. Future computing platforms will need to not only scale out traditional workloads, but support these new applications as well./nThis dissertation proposes an architecture for cluster computing systems that can tackle emerging data processing workloads while coping with larger and larger scales. Whereas early cluster computing systems, like MapReduce, handled batch processing, our architecture also enables streaming and interactive queries, while keeping the scalability and fault tolerance of previous systems. And whereas most deployed systems only support simple one-pass computations (e.g. aggregation or SQL queries), ours also extends to the multi-pass algorithms required for more complex analytics (e.g. iterative algorithms for machine learning). Finally, unlike the specialized systems proposed for some of these workloads, our architecture allows these computations to be combined, enabling rich new applications that intermix, for example, streaming and batch processing, or SQL and complex analytics./nWe achieve these results through a simple extension to MapReduce that adds primitives for data sharing, called Resilient Distributed Datasets (RDDs). We show that this is enough to efficiently capture a wide range of workloads. We implement RDDs in the open source Spark system, which we evaluate using both synthetic benchmarks and real user applications. Spark matches or exceeds the performance of specialized systems in many application domains, while offering stronger fault tolerance guarantees and allowing these workloads to be combined. We explore the generality of RDDs from both a theoretical modeling perspective and a practical perspective to see why this extension can capture a wide range of previously disparate workloads.

Advisor: Shenker, Scott J
Stoica, Ion
Anthrax lethal toxin unfolding and translocation via a charge-state ratchet

A fundamental problem in biochemistry is how molecular machines convert chemical potential energy into mechanical work. Here, this problem is addressed in terms of how a proton gradient (ΔpH) drives anthrax toxin transmembrane protein translocation with a given directionality. One model to explain this phenomenon is a charge-state Brownian ratchet, wherein movement is biased by asymmetries across the membrane. Acidic residues in the substrate are protonated on the lower pH starting side, thus allowing them to pass through the cation-selective protective antigen (PA) channel. Movement can occur in either direction according to Brownian motion, but acidic residues that reach the higher pH of the destination are deprotonated, preventing retrotranslocation and resolving movement in one direction./nThis model is probed through the use of planar lipid bilayer electrophysiology to analyze the charge requirements of the model substrate LFN, the binding domain of the natural substrate lethal factor. Acidic residues are necessary and sufficient for ΔpH-driven translocation provided the starting side pH is low enough to sufficiently protonate the residues. Their position in the sequence, just before LFN's folded domain, plays a key role in substrate unfolding. Basic charges are important for initiation into the channel and to chaperone deprotonated acidic residues during translocation./n/nFurther work by Sarah Wynia-Smith confirms the importance of acidic residues just before LFN's folded domain and points to the existence of electrostatic translocation barriers in the PA channel. I identify key residues in the upper portion of the channel's β barrel that contribute to its cation selectivity. These residues also prove to play a significant role in substrate initiation and translocation, supporting the role for a charge gate in the channel that prevents retrotranslocation./nFinally, secondary structure of the translocating substrate is analyzed. LFN translocates in a compact helical state nucleated by the channel's α clamp, a nonspecific helix-binding site recently identified by Geoffrey Feld. α clamp-induced helix formation lowers a previously identified but uncharacterized translocation barrier, and substrates that cannot form helices cannot translocate. This suggests a mechanism wherein helix melting, coupled to the electrostatic ratchet, drives translocation-coupled substrate unfolding.

Advisor: Krantz, Bryan
After the Blast: Building and Unbuilding Memories of Port Chicago

Located in the San Francisco Bay Area, Port Chicago came to international attention on July 17, 1944 when two ammunition ships exploded, killing 320 military personnel. Two-thirds of those killed were African American stevedores ordered to load munitions under a segregated Navy. It was the worst domestic disaster during World War II. Three weeks after the blast, hundreds of survivors refused to return to work in a spontaneous wildcat strike. Fifty of these men were convicted of mutiny charges by an all-white military tribunal, a catalyst for the 1948 Executive Order that desegregated the Armed Forces. When President Barack Obama signed the 2010 defense budget, he also approved a subsection that created a new national park: The Port Chicago Naval Magazine National Memorial. While the creation of the national park could be conflated with a symbolic closure to these struggles, my research finds that the memory of Port Chicago is contested through various spatial imaginaries. Furthermore, because the site is ensconced within an active base, the military controls access to this memorial--a rare case. As such, it crystallizes usually unnoticed tensions between public space and national memory. I study these tensions at Port Chicago and other Bay Area sites of the World War II home front related to the popularized "Port Chicago story." I find that different groups create their own narrative of the military past, sometimes challenging National Park Service narratives, and sometimes also exacerbating social and racial separation.

Advisor: Walker, Richard
Characterization of Thallium Bromide (TlBr) for Room Temperature Radiation Detectors

Thallium bromide (TlBr) has emerged as a remarkably well-suited material for room temperature radiation detection. The unique combination of high-Z elements, high density, suitable band gap, and excellent electrical transport properties present in TlBr have brought device performance up to par with CdZnTe (CZT), the current market-leading room temperature radiation detector material. TlBr research is at an earlier stage than that of CZT, giving hope that the material will see even further improvement in electronic properties./n/nImproving a resistive semiconductor material requires knowledge of deep levels present in the material and the effects of these deep levels on transport properties. Very few deep level studies have been conducted on TlBr, and none with the depth required to generate useful growth suggestions. In this dissertation, deep levels in nominally undoped and doped TlBr samples are studied with electrical and optical methods. Photo-Induced Conductivity Transient Spectroscopy (PICTS) is used to discover many deep levels in TlBr electrically. These levels are compared to sub-band gap optical transitions originating from defects observed in emission spectra. The results of this research indicate that the origin of resistivity in TlBr is likely due to deep level defects pinning the Fermi level at least ∼0.7 eV from either the conduction or valence band edge. The effect of dopants and deep levels on transport in TlBr is assessed with microwave photoconductivity decay analysis. It is found that Pb-, Se-, and O-doping decreases carrier lifetime in TlBr, whereas C-doping does not./nTlBr exhibits weak ionic conductivity at room temperature, which both negatively affects the leakage current of detectors and leads to device degradation over time. Researchers are actively looking for ways to reduce or eliminate the ionic conductivity, but are faced with an intriguing challenge of materials engineering: is it possible to mitigate the ionic conduction of TlBr without harming the excellent electronic transport properties? Doping TlBr in order to control the ionic conductivity has been proposed and shown to be effective in reducing dark ionic current, but the electronic effects of the dopants has not been previously studied in detail. In this dissertation, the electronic effects of dopants introduced for ionic reasons are evaluated.

Advisor: Haller, Eugene E
Chrzan, Daryl C
Eliciting Private Information from Selfish Agents

Ever since the Internet opened the floodgates to millions of users, each looking after their/nown interests, modern algorithm design has needed to be increasingly robust to strategic/nmanipulation. Often, it is the inputs to these algorithms which are provided by strategic/nagents, who may lie for their own benefit, necessitating the design of algorithms which/nincentivize the truthful revelation of private information - but how can this be done? This is a/nfundamental question with answers from many disciplines, from mechanism design to scoring/nrules and prediction markets. Each domain has its own model with its own assumptions, yet/nall seek schemes to gather private information from selfish agents, by leveraging incentives./nTogether, we refer to such models as elicitation./nThis dissertation unifies and advances the theory of incentivized information elicitation./nUsing tools from convex analysis, we introduce a new model of elicitation with a matching/ncharacterization theorem which together encompass mechanism design, scoring rules, prediction markets, and other models. This lays a firm foundation on which the rest of the/ndissertation is built./nIt is natural to consider a setting where agents report some alternate representation of/ntheir private information, called a property, rather than reporting it directly. We extend/nour model and characterization to this setting, revealing even deeper ties to convex analysis/nand convex duality, and we use these connections to prove new results for linear, smooth/nnonlinear, and finite-valued properties. Exploring the linear case further, we show a new/nfour-fold equivalence between scoring rules, prediction markets, Bregman divergences, and/ngeneralized exponential families./nApplied to mechanism design, our framework offers a new perspective. By focusing on/nthe (convex) consumer surplus function, we simplify a number of existing results, from the/nclassic revenue equivalence theorem, to more recent characterizations of mechanism implementability./nFinally, we follow a line of research on the interpretation of prediction markets, relating/na new stochastic framework to the classic Walrasian equilibrium and to stochastic mirror/ndescent, thereby strengthening ties between prediction markets and machine learning.

Advisor: Papadimitriou, Christos H
The Unseen World: Denarrative Desire in the Contemporary British Novel

This dissertation proposes a new theoretical account of the contemporary British novel's vexed relationship to history. This project examines novels that attempt to rewrite narratives of violence and imperialism through what I see as failed magic tricks: fantastical reinventions of earlier literary or historical texts that ultimately prove untenable. This impulse resists the demystifying attitude of the postmodern novel, exemplified in John Fowles' The French Lieutenant's Woman (1969), where the ever-present figure of the novelist makes analytical intrusions into the Victorian plot. Instead, the novels that I examine--including works by Peter Ackroyd, Graham Swift, A.S. Byatt, and David Mitchell--beguile readers into a temporary state of willful desire for historical recuperation. However, these would-be narrative enchantments threaten violence and pose dark ethical quandaries for both author and reader. This threat of complicity emerges in Ackroyd's Hawksmoor (1985), through the reader's uneasy sympathy for the novel's twinned anti-heroes, a murderer and a detective separated by two hundred years, yet illogically involved in the same crimes. In what I call the necropolitan chronotope of Ackroyd's London, distinctions between these temporally distant characters deteriorate, as do those between life and death, good and evil. Past and present coalesce into a nightmarish void of time, in which attempts at narrative or historical resolution inevitably backfire: events can be neither changed nor undone because they are in a state of perpetual manifestation./nI contend that these recent texts express a compulsive denarrative desire to undo or unknow pre-existing narratives, a wish that can never be responsibly fulfilled. This drive is fetishistic; the authors I consider recognize the impossibility of historical revision but enact it nonetheless, through formal experiments that critics often inadequately categorize as belated versions of postmodern irony or playfulness. These over-familiar terms fail to account for the serious claims that these novels make about the uncomfortable inextricability of the past and the present. For example, in Cloud Atlas (2004), Mitchell constructs densely interlocking layers of pastiche and a unique nested structure that moves first forwards, then backwards in time. Mitchell hews close to metanarratives of modernization and literary history, only to confound both. By considering texts like Cloud Atlas that hover outside the postmodern in the nebulous area of the "post-postmodern," my project traces an alternative lineage of the contemporary novel. Alongside these theoretical questions about history, narrative form, and periodization, The Unseen World interrogates the contentious status of the British novel in relation to broader European, Anglophone, and "world" literary landscapes.

Advisor: Serpell, C. Namwali
The MINIS Balloon Campaign: Duskside Relativistic Electron Precipitation

Abstract/nThe MINIS Balloon Campaign:/nDuskside Relativistic Electron Precipitation/nby/nJohn Glen Sample/nDoctor of Philosophy in Physics/nUniversity of California, Berkeley/nProfessor Frances Hellman, Chair/nThe Earth's radiation belts are a dynamic population of highly-energetic (> MeV) electrons and ions trapped in the dipole geometry of the Earth's magnetic field . These particles can strongly influence atmospheric chemistry, satellite operations, human explorers, long distance communications and even the electrical grid. The belts are also the most accessible laboratory for study of the particle acceleration that we see taking place throughout the universe. This dissertation presents the results from the MINIS balloon campaign, a January 2005 effort to observe the loss of relativistic electrons from the belts through relativistic electron precipitation (REP). MINIS launched 6 balloon payloads equipped with X-ray spectrometers into high-altitude, high-latitude, long-duration flights. These flights took place during a dramatic series of solar activity that set off a -99 Dst geomagnetic storm. During the storm sudden commencement phase, three payloads measured bremsstrahlung X-rays from electrons hitting the top of the atmosphere, making MINIS the first multi-point measurement of relativistic electron precipitation. The observations took place at dusk local times, consistent with other high energy precipitation observations from single point balloons. Measuring the scale size and motions of the precipitation region as well as its energy and intensity allow improved measurement of the average loss rate as well as more tightly constraining the instantaneous loss rate from the belts. Scale sizes and motions can also be better tied to the physical structures in the belts which lead to these particle losses. During the MINIS observed precipitation, the scale size was at least 0.6 L (a unit of Earth radii when mapped to the magnetic equator) by 1 hour of magnetic local time, and expansion rates of the precipitation were well faster than the drift rate for ~MeV electrons. The MINIS balloons also served as a proof of concept for a much larger balloon campaign that began in January 2013 and will continue at least until February 2014. That campaign, BARREL, and estimates of what it will observe as well as a possible satellite mission to observe REP are also detailed here.

Advisor: Lin, Robert P
Smith, David M
"A Plumb Craving for the Other Color": White Men, Non-White Women, and Sexual Crisis in Antebellum America

This dissertation examines interracial relations between white men and non-white women in the antebellum period. Focusing on black, Indian, and Spanish American women, this dissertation argues that such liaisons were far more prevalent, institutionalized, and tolerated than historians have previously argued. Although such phenomena as black concubines, tribally organized Indian marriages, and land-rich Mexican wives have been separately examined, no single study has put them together and questioned their particular prevalence at a specific time in American history. This dissertation argues that the relationships white men formed with non-white women follow certain patterns that evidence a sexual "crisis" in antebellum America. This is specifically identified as a "crisis of white femininity," wherein cultural stereotypes of virile white men, passionless white women, and hyper-sexual non-white women created a significant threat to stable white marriages. Moreover, this dissertation argues that the romanticization of such relations extended far beyond the men who contracted them: some of the period's most popular fiction involved fantasies of interracial love, pointing to a far more deep-seated fascination and desire within the American public than has hitherto been acknowledged.

Advisor: Fass, Paula