VictorJuiz/thesis huggingface dataset:
On the Roles of Information in the Interaction of Agents in Markets

Markets are rich environments for study. Two features in particular make them attractive settings for the study of the roles of information. First, they are often characterized by a significant amount of uncertainty, an essential ingredient for information to be relevant. Second, strategic interactions abound./nEach chapter of this dissertation uses a different `lens' so as to focus on particular roles of information in strategic market settings. First, information is considered in its pure `aid to decision-making' role, in which agents use it to improve their decisions, not only based on the expected future conditions but also on the expected actions of the other agents which in turn depend on the information they are likely to hold. Second, information is considered in its `influencer' and `coordinator' roles. It can be used to influence the decisions of agents which will in turn affect the welfare of the original transmitters, while increasing overall market coordination. Finally, information is considered in its `homogenizer' role, in the sense that actions and preferences may become more similar after its repeated use and subsequent transmission. The purpose of this study is to propose, document and estimate mechanisms by which information fulfills these specific roles in actual market settings./nThis dissertation is organized in the following way. Chapter 1 analyzes the use of information acquired by decision-makers in a strategic context. Chapter 2 introduces the layer of the information transmitter as a separate strategic entity, who may have different interests from those of the receivers. Finally, Chapter 3 considers the case where the same agents are simultaneously receivers, users and transmitters of information./nThese scenarios are analyzed in well-defined market contexts. Chapter 1 looks at the role of information in the production and capacity decisions of DRAM producers. I estimate the precision of market information used by firms in the DRAM industry, implicit in the patterns and accuracy of their actions. The value of information is estimated as well as its impact on the decisions of the firms./nChapter 2 investigates advertising between firms and consumers in a market for a search good. It is shown that even if firms have an interest in providing biased information through advertising, it is still possible for it to convey credible content that may be useful to consumers. In addition it is shown that the precision of information delivered is sparser as the quality of the product or service in question decreases./nFinally, Chapter 3 analyzes the context of online movie ratings and estimates how the opinions of consumers shape the opinions of subsequent consumers, ad infinitum. It is estimated that roughly half of the consumers' valuations for movies is a function of the valuations of other consumers who have had a chance to rate the movie earlier. A sensitivity analysis of how some extreme initial ratings influence consumer valuations is performed, revealing considerable effects.

Advisor: Villas-Boas, Joao M
Double Groupoids, Orbifolds, and the Symplectic Category

Motivated by an attempt to better understand the notion of a symplectic stack, we introduce the notion of a \emph{symplectic hopfoid}, which should be thought of as the analog of a groupoid in the so-called symplectic category. After reviewing some foundational material on canonical relations and this category, we show that symplectic hopfoids provide a characterization of symplectic double groupoids in these terms. Then, we show how such structures may be used to produce examples of symplectic orbifolds, and conjecture that all symplectic orbifolds arise via a similar construction. The symplectic structures on the orbifolds produced arise naturally from the use of canonical relations./nThe characterization of symplectic double groupoids mentioned above is made possible by an observation which provides various ways of realizing the core of a symplectic double groupoid as a symplectic quotient of the total space, and includes as a special case a result of Zakrzewski concerning Hopf algebra objects in the symplectic category. This point of view also leads to a new proof that the core of a symplectic double groupoid itself inherits the structure of a symplectic groupoid. Similar constructions work more generally for any double Lie groupoid---producing what we call a \emph{Lie hopfoid}---and we describe the sense in which a version of the ``cotangent functor'' relates such hopfoid structures.

Advisor: Weinstein, Alan
Bio-fabrication: Experiments and Experiences in Ethics and Sciences

Bio-fabrication: Experiments and Experiences in Ethics and Sciences provides an account of an experiment I undertook in ethics and anthropology as part of the International Open Facility Advancing Biotechnology, the BIOFAB. It offers an analysis of the facility's programmatic attempt to actualize a core claim of the new field of synthetic biology: that living beings can be conceived as collections of interoperable genetic components, constructed through rational design, standardized, and fabricated at scale. It provides a diagnosis of the scientific, vocational, and ethical limits of this endeavor. And demonstrates why, in the end, loyalty to truth and seriousness required an exit from the both the mode and stakes of my undertaking./nMy experiment with the BIOFAB constituted a distinctive and final phase of a five-year project to design Human Practices, which began as part of the Synthetic Biology Engineering Research Center (SynBERC). Extending ontological and ethical lines of inquiry characteristic of an anthropology of the contemporary, I asked: how are researchers in the BIOFAB bringing things into the world? How are they naming these things, distributing, and modifying them? Equally important, what habits, dispositions, and capacities are being cultivated and managed in order to make such ontological work possible? And, most crucially, what is the price to be paid?/nFollowing intensive participation-observation of the biologists whose task was to put into operation the BIOFAB's strategic vision, the dissertation examines a double-bind at the heart synthetic biology: those who are most capable of taking on the technical challenge of standardizing biological parts are also those least ready to fully commit themselves to such a vision for the future of bioengineering. The ethical and scientific challenge for these biologists was thus how to take a stance toward their work that would simultaneously allow them proceed with a technically difficult experiment, while distancing themselves from the lack of scientific seriousness often attributed to the BIOFAB's undertaking. As the thesis demonstrates, a similar challenge proved equally troublesome for me./nThe dissertation concludes that the attempt to incorporate ethics and anthropology as defining elements of synthetic biology reactivates a typically modern problem. Despite efforts to remediate the relations of ethics and science, actual asymmetry in power between biologists and non-biologists encumbers such work. Crucially, the thesis shows that this problem is as characteristic of governance at the highest levels as it is the micro-practices of life in the BIOFAB. In the case of my experiment, such difficulties initially required raising a second-order question: how are asymmetries in power being formed and how might they be unsettled? Ultimately, however, they required an ethics of exit: how can persistent disconnections between power, truth, and ethics be productively refused and, where necessary, left behind?

Advisor: Rabinow, Paul
Pathways to the Oral and Written Language Competence Among Young Vietnamese English Language Learners

This case study, drawing upon the ecological perspectives (Kramsch, 2002; van Lier, 2004) as a theoretical framework, described the learning experiences of two second generation and first grade Vietnamese English Language Learners navigating between home and school to develop oral and written L1 Vietnamese and L2 English competence for one school year. In the second school year, the focal students' oral and written language samples were collected without classroom observations or interviews. Focal student one had the advantage of learning language in three settings--home, public school, and Vietnamese Sunday School--while focal student two had access to the first two only. A variety of qualitative tools were developed to capture the language affordance, interaction and emergence of ELL learners: (a) observation fieldnotes (b) parent and teacher interviews, and (c) L1 and L2 oral and written reading survey and assessment. Metalinguistic awareness, through language play, language rehearsal and repeated reading emerged as an important mediator of language competence and as an interpretative framework to drive the analytic induction process (Erickson, 1986; Bogdan & Biklen, 2003) that I employed. Data interpretation focused on the L1 Vietnamese and L2 English oral and written modes./nThe study findings suggest that when teachers, parents and students collaborate to generate and activate the L1 and L2 language affordances (van Lier, 2000) of Vietnamese ELLs through reflexive form of interaction, language learning and competence will emerge. Awareness of language form and function assisted focal students in developing L1 and L2 oral and written competence. Overall, reading assessment results indicate moderate-high growth by the end of the school year for focal student one. She mastered the early reading abilities, such as letter names and sounds, high frequency word and decodable words in L1 Vietnamese and L2 English. Listening and reading comprehension improved more for L2, compared to L1. Focal student two, who had access to only 2 sites (home and public school), showed low-moderate growth in listening and reading comprehension skills in L2 English. Her L2 early reading skills were high, compared to no improvement in L1. There was no growth in L1 listening and reading comprehension through oral retell and writing tasks. Because observations began at the start of first grade, after one year of L2 English exposure in kindergarten, both focal students used more L2 oral language to communicate with family members, peers and teachers. Focal student one/nincreased her codeswitching as her fluency improved in both L1 Vietnamese and L2 English at age six. Additional participation in Vietnamese Sunday School was beneficial for focal student one as evidenced by her overall improvement in L1 Vietnamese and L2 English oral and written language competence.

Advisor: Pearson, P David
Replay Debugging for the Datacenter

Debugging large-scale, data-intensive, distributed applications running in a datacenter ("datacenter applications") is complex and time-consuming. The key obstacle is non-deterministic failures--hard-to-reproduce program misbehaviors that are immune to traditional cyclic debugging techniques. Datacenter applications are rife with such failures because they operate in highly non-deterministic environments: a typical setup employs thousands of nodes, spread across multiple datacenters, to process terabytes of data per day. In these environments, existing methods for debugging non-deterministic failures are of limited use. They either incur excessive production overheads or don't scale to multi-node, terabyte-scale processing./nTo help remedy the situation, we have built a new deterministic replay tool. Our tool, called DCR, enables the reproduction and debugging of non-deterministic failures in production datacenter runs. The key observation behind DCR is that debugging does not always require a precise replica of the original datacenter run. Instead, it often suffices to produce some run that exhibits the original behavior of the control-plane--the most error-prone component of datacenter applications. DCR leverages this observation to relax the determinism guarantees offered by the system, and consequently, to address key requirements of production datacenter applications: lightweight recording of long-running programs, causally consistent replay of large-scale clusters, and out-of-the box operation with existing, real-world applications running on commodity multiprocessors.

Advisor: Stoica, Ion
Numerical Investigation of Operational Shocks and Vibrations in Mobile Hard Disk Drives

Over the last decade, there has been a continuous increase in the demand of hard disk drives (HDDs) for the mobile applications. In such devices, HDDs are often subjected to mechanical shocks and vibrations. Such external disturbances can degrade the read/write (R/W) performance of mobile drives and in extreme cases it can even cause the loss of stored magnetic information. Hence the ability of the head-disk interface (HDI) to withstand such excitation becomes critical in determining the reliability of a mobile disk drive. This dissertation presents a simulation method to accurately model the response of a mobile HDD to external disturbances which can aid the design process./nA numerical investigation was conducted on a 2.5 inch form factor laptop drive to understand the dynamics of the HDI during dynamic events such as operational shocks. A detailed model for the mobile disk drive was developed which includes a spinning disk, a fluid dynamic bearing (FDB) based spindle motor, a base plate and an actuator. The behavior of the HDI subjected to various disturbances was determined by solving a fluid-structure interaction problem in which a spinning disk and a head (slider) were coupled through an air bearing. Case studies were conducted to determine the effect of parameters like shock pulse width, HDD orientation, parking ramp contact and FDB dynamic coefficients on the performance of a HDD during the excitation./nIt was observed that the proximity of the pulse to the HDD component's natural frequencies has an adverse effect on the shock resistance of the HDI. Furthermore, the orientation of the HDD during the shock can also affect the stability of the HDI. In the case of planar excitations, the FDB dynamics becomes critical in determining the slider's vibration amplitude. This knowledge about the HDI failure mechanism and its vibration characteristics can be helpful in designing a mobile HDD with a better shock performance.

Advisor: Bogy, David B
A measurement of the 2 neutrino double beta decay rate of 130Te in the CUORICINO experiment

CUORICINO was a cryogenic bolometer experiment designed to search for neutrinoless/ndouble beta decay and other rare processes, including double beta decay with two neutrinos/n(2νββ). The experiment was located at Laboratori Nazionali del Gran Sasso and ran for a period of about 5 years, from 2003 to 2008. The detector consisted of an array of 62 TeO2 crystals arranged in a tower and operated at a temperature of ∼10 mK. Events depositing energy in the detectors, such as radioactive decays or impinging particles, produced thermal pulses in the crystals which were read out using sensitive thermistors./nThe experiment included 4 enriched crystals, 2 enriched with 130Te and 2 with 128Te, in order to aid in the measurement of the 2νββ rate. The enriched crystals contained a total of ∼350 g 130Te. The 128-enriched (130-depleted) crystals were used as background monitors, so that the shared backgrounds could be subtracted from the energy spectrum of the 130-enriched crystals. Residual backgrounds in the subtracted spectrum were ﬁt using spectra generated by Monte-Carlo simulations of natural radioactive contaminants located in and on the crystals. The 2νββ half-life was measured to be T1/2 = [9.81 ± 0.96(stat) ± 0.49(syst)]×/n1020 y.

Advisor: Freedman, Stuart J
Control Design and Implementation of Hard Disk Drive Servos

In this dissertation, the design of servo control algorithms is investigated to produce high-density and cost-effective hard disk drives (HDDs). In order to sustain the continuing increase of HDD data storage density, dual-stage actuator servo systems using a secondary micro-actuator have been developed to improve the precision of read/write head positioning control by increasing their servo bandwidth. In this dissertation, the modeling and control design of dual-stage track-following servos are considered. Specifically, two track-following control algorithms for dual-stage HDDs are developed. The designed controllers were implemented and evaluated on a disk drive with a PZT-actuated suspension-based dual-stage servo system./nUsually, the feedback position error signal (PES) in HDDs is sampled on some specified servo sectors with an equidistant sampling interval, which implies that HDD servo systems with a regular sampling rate can be modeled as linear time-invariant (LTI) systems. However, sampling intervals for HDD servo systems are not always equidistant and sometimes, an irregular sampling rate due to missing PES sampling data is unavoidable. With the natural periodicity of HDDs, which is related to the disk rotation, those HDD servo systems with missing PES samples can be modeled as linear periodically time-varying (LPTV) systems./nFor the control synthesis of HDD servos with irregular sampling rates, an explicit optimal H_infinity control synthesis algorithm for general LPTV systems is first obtained by solving discrete Riccati equations. Then, the optimal H_infinity track-following control for irregular-sampling-rate servos is synthesized. Simulation and experiment studies, which have been carried out on a set of actual single-stage hard disk drives, demonstrate that the proposed control synthesis technique is able to handle irregular sampling rates and can be used to conveniently design a track-following servo that achieves the robust performance of a desired error rejection function for disturbance attenuation. Moreover, experiment results show that compared to the currently-used methodology for irregular sampling rates, the proposed control algorithm has significantly improved the servo performance./nIn addition, the feedback signal in HDD servos is generated from the servo patterns that must be pre-recorded using servo track writing process before the HDD can be used. Thus, the quality of the servo track writing process is also crucial to the accuracy of positioning read/write head. Recently, self-servo track writing has been developed in order to improve the quality of the written servo patterns and reduce the cost of servo track writing process. This dissertation considers two novel controller synthesis methodologies employing a feedforward control structure for performing concentric self-servo track writing in hard disk drives. Simulation results confirm that the two proposed control synthesis methodologies prevent error propagation from the previously written tracks and significantly improve servo track writing performance.

Advisor: Horowitz, Roberto
From Red Lights to Red Flags: A History of Gender in Colonial and Contemporary Vietnam

This dissertation argues that the public discourse of Vietnam's periods of modernity--the late French colonial era (1930-1940) and that of the post-socialist decades (1986-2005)--produced interlocking notions of what I call queer subjects, subjects who oppose or exceed a normative understanding of heterosexual reproduction. The dissertation posits, however, a diachronic rupture in the dominant meaning of queer between these two periods. Whereas the former exhibited a capacious vision of gender and sexuality, one that pushed the imagined frontiers of the human body, the post-socialist decades marked a retreat to a static notion of mythic tradition that pathologized and purged queer bodies through recourse to a late nineteenth-century European discourse of gender-inversion, the notion of a man "trapped" in a women's body or vice versa. To demonstrate this change, the first chapter argues that the normative meaning of gender and sexuality in late colonial Vietnam was far more dynamic and expansive than the contemporary scholarship has acknowledged. The second chapter maintains that the sexual regime that Foucault and others scholars have identified in Europe reaches its limit in the Vietnamese colony. The third and final chapter demonstrates the emergence of this sexual regime, albeit in transmuted form, during Vietnam's post-socialist decades (1986-2005). Together these chapters support the overall argument of a historical rupture in the cultural meaning of queer genders and sexualities between the period of late French colonialism and post-socialism. In reconstructing this rupture, the dissertation aims to de-familiarize contemporary practices and commitments and, by so doing, illuminate viable alternative forms of gendered and sexual life in twentieth-century Vietnam.

Advisor: Butler, Judith
Zinoman, Peter
Multidimensional Spectroscopy of Photosynthetic Complexes

Experiments using two-dimensional (2D) electronic spectroscopy to investigate the structure-function relationships that give rise to photosynthetic energy transfer within pigment protein complexes are presented and discussed in this dissertation. 2D electronic spectroscopy using ultrafast laser pulses throughout the visible regime was applied to study excitation energy transfer in the major light harvesting complex of photosystem II (LHCII) and the reaction center from purple bacteria. These experiments elucidated information about the excited state structure and the energy transfer timescales within these complexes. All-parallel 2D spectroscopy was used to monitor the energy transfer dynamics in LHCII and reveals previously unobserved sub-100 fs energy transfer between the chlorophyll-b (Chl-b) and chlorophyll-a (Chl-a) bands and within the Chl-a band. Reproducing these results with simulations led to improvements in the values of the uncoupled transition energies of the chlorophyll in the working Hamiltonian of LHCII. The delocalized excited states observed in the experimental and theoretical results were found to increase the range of optimal angles for energy transfer from LHCII to neighboring pigment-protein complexes, as opposed to the case of a single, isolated donor excited state. Polarized 2D spectroscopy experiments reported here identified previously unresolved excitation energy transfer steps in LHCII. These results were used to determine the angle between/ntransition dipole moments of the donor and acceptor. A new method was developed to use the angle between transition dipole moments to find the uncoupled transition energies of the chlorophyll, previously the major unknown for an accurate electronic Hamiltonian. This method was applied to LHCII. Quantum coherence, or a long-lived superposition of excited states, was observed in LHCII using a second polarization sequence. The observable timescales of coherence was determined to be 700-900 fs, which illustrates that quantum coherence lasts longer than many energy transfer steps. The potential contribution of coherence to the robustness of photosynthetic energy transfer to the rugged energy landscape and to temperature variations is discussed. Experiments on the B band of the bacterial reaction center were able to isolate the previously inseparable two peaks and observe energy transfer between these two excited states. A new extension of 2D spectroscopy, two-color 2D spectroscopy, was demonstrated for/nexamining the interactions between two spectrally separate chromophores. Using this approach, energy was found to transfer from the carotenoid to the bacteriochlorophyll both via S1 and via Qx in the bacterial reaction center in an approximately 2:1 ratio, and within about 750 fs.

Advisor: Fleming, Graham R