VictorJuiz/thesis huggingface dataset:
Autonomous ultra-low power ELF/VLF receiver systems [electronic resource]

ELF/VLF radio signals, from approximately 300Hz to 30KHz, are commonly used for submarine communications, ionospheric remote sensing, geophysical prospecting, and studies of the near-Earth space environment. Naturally occurring ELF/VLF emissions caused by nearly every lightning strike can be detected for thousands of miles and provide an abundance of wave-particle interaction possibilities in the radiation belts. Any applied studies of these events, however, require electromagnetic waves in the ELF/VLF band to be amplified, captured, analyzed, and stored. Specific studies often require the placement of receivers in extremely remote locations such as Antarctica or the middle of an ocean, and are almost always located far away from power sources to decrease noise. These scientific requirements drive the creation of new ELF/VLF receiver systems. Two new receiver systems were designed for use in terrestrial, typically Antarctic, locations. Both new systems utilize 10-100 times less power than the lowest-power comparable existing ELF/VLF receivers and were designed for remote unmanned operation in extreme environments without external power. The so called Penguin system, comprised of a hybrid microcontroller and FPGA architecture, removes the overhead of a general purpose CPU to provide the most streamlined processing for data acquisition possible while still maintaining a relatively traditional sampling architecture. The drastically reduced architecture of the Penguin system, compared to traditional receiver systems, on average consumes less power than a typical LED indicator lamp while capturing high fidelity ELF/VLF magnetic field snapshots every fifteen minutes. The low power and thermal requirements of the Penguin system enables low-cost remote studies of medium to large timescale phenomena such as Chorus and Auroral Hiss without the need for local power. The system has been deployed and operated at the United States Amundsen Scott South Pole Station in Antarctica. A second ELF/VLF receiver architecture, the VLF Advanced Technology platform, or "VAT", removes the typical CPU from the sampling and recording loop further reducing power requirements and physical system size while gaining the ability to record continuously. This radically new architecture enables future scientific studies of the fine structure in time and frequency of long-term events, such as the onset mechanisms of natural Chorus emissions, due to the extremely low power requirements. The system architecture is also greatly applicable to any continuous time recording system, including but not limited to acoustic and electromagnetic arrays for subsurface imaging systems, ionospheric remote sensing, and optical sensors.

Keywords: Electrical Engineering
Advisor: Inan Umran S. primary advisor. Thesis advisor
Linscott Ivan advisor. Thesis advisor
Nishimura Dwight George advisor. Thesis advisor
Body Language Animation Synthesis from Prosody

Human communication involves not only speech, but also a wide variety of gestures and body motions. Interactions in virtual environments often lack this multi-modal aspect of communication. This thesis presents a method for automatically synthesizing body language animations directly from the participants’ speech signals, without the need for additional input. The proposed system generates appropriate body language animations in real time from live speech by selecting segments from motion capture data of real people in conversation. The selection is driven by a hidden Markov model and uses prosody-based features extracted from speech. The training phase is fully automatic and does not require hand-labeling of input data, and the synthesis phase is efficient enough to run in real time on live microphone input. The results of a user study confirm that the proposed method is able to produce realistic and compelling body language.

Keywords: Computer Science.
Human-computer interaction
Computer animation
Firestone Medal for Excellence in Undergraduate Research
Ben Wegbreit Prize for Best Undergraduate Honors Thesis in Computer Science
Thesis
Advisor: Koltun Vladlen
Theobalt Christian
Capital Structure as a Form of Signaling: The Use of Convertible Bonds

In the face of asymmetrical information in financial markets, outside investors must rely on the firms’ actions in order to gain information known only to firm insiders. Such actions can be construed as signals of firm quality or internal projections of success, and capital structure can serve as one such signal. This study uses a sample of 100 convertible bonds issued from 1990 to 2007 to examine the market’s reactions to changes in the capital structures of the firms. A more debt-like issuance is theorized to result in positive abnormal returns, while a more equity-like issuance should result in negative abnormal returns. I also intend to investigate whether the use of capital structure as signaling differs with firms of different sizes, since information asymmetries would not be the same. This paper finds that the conversion premium of newly issued convertible bonds has a positive, statistically significant effect on the firms’ abnormal returns in the 30- and 200-day periods around the date of issuance. This effect is larger for smaller firms than for larger firms. However, the conversion premium has a much smaller, insignificant effect during the 10-day period, which may be caused by errors in determining the correct date that the market learned of the issuance

Keywords:  Department of Economics
Stanford Department of Economics
Thesis
Advisor: Shoven John B.
Carbon nanotubes [electronic resource] : device physics, RF circuits, surface science, and nanotechnology

In this dissertation, we report on our research to advance the understanding and development of carbon nanotubes into a functional nanotechnology that will enable novel applications and products. Our research approach is interdisciplinary in nature involving progress on many fronts including material synthesis, device physics and compact modeling, circuits, and monolithic integration with silicon substrates for optimum performance and integration. Specifically, this dissertation reports new results advancing the science and technology of carbon nanotubes including: i) analytical development of the physics of CNTs providing direct insight into the electro-physical properties, ii) experimentally-verified analytical current-voltage and capacitance-voltage characteristics of CNTs facilitating circuit design and analysis, iii) elucidation of the material science of nanotube synthesis enabling large-scale synthesis of aligned growth, and iv) monolithic integration of CNTs and CMOS for hybrid nanotechnology for future nanoelectronics.

Keywords: Electrical Engineering
Advisor: Wong Hon-Sum Philip
Dutton Robert W. advisor. Thesis advisor
Nishi Yoshio
Cell identity and wiring specificity in the Drosophila olfactory system [electronic resource]

The brain is a complex organ formed from billions of neurons. There are thousands of types of neurons, each with a unique morphology, function, gene expression profile and pattern of connectivity. This structure poses a very interesting developmental challenge: how do neurons acquire unique identities and connect to specific partner neurons during development? The Drosophila antennal lobe presents an attractive genetic model system in which to investigate these questions. In the antennal lobe, olfactory receptor neuron (ORN) axons project to glomeruli where they synapse with their partner projection neuron (PN) dendrites. These connections are highly stereotyped, as ORNs expressing the same odorant receptor converge on the same glomerulus and all PNs of the same class send their dendrites to the same glomerulus. Cell surface molecules are known to be crucial to instructing this specific wiring during development, and a transcriptional code likely dictates which cells express a particular cell surface molecule. However, the identities of many of these cell surface molecules and transcription factors remain unknown, and it is possible that additional cell types also inform the specific wiring of PNs and ORNs. In this thesis, I present work that furthers our understanding of the development and function of the fly olfactory circuit. First, I discuss a detailed characterization of local interneurons in the antennal lobe, dramatically expanding our basic knowledge of the types of cells present during development as well as central to information processing in the antennal lobe. Second, I present my work on the transcription factor longitudinals lacking (lola) that plays a role both in fate determination and wiring specificity of olfactory projection neurons, the second order cells that relay olfactory information to higher brain centers. Finally, I present an analysis of the regulatory elements driving expression of the projection neuron marker GH146 as a first step in defining transcriptional regulatory modules and identifying factors that may direct fate and wiring decisions in PNs.

Keywords: Biology.
Advisor: Luo Liqun
Clandinin Thomas R. (Thomas Robert)
McConnell Susan K. advisor. Thesis advisor
Shen Kang
Chemical inhibitor studies of polo-like kinase 1 in late mitosis and cytokinesis [electronic resource]

During cell division, chromosome segregation must be coordinated with cell cleavage so that cytokinesis occurs after chromosomes have been safely distributed to each spindle pole. Polo like kinase 1 (Plk1) is an essential kinase that regulates spindle assembly, mitotic entry and chromosome segregation but because of its many mitotic roles it has been difficult to specifically study its post-anaphase functions. Small molecule inhibitors were used to block Plk1 activity at anaphase onset and demonstrate that Plk1 controls both spindle elongation and cytokinesis. Plk1 inhibited cells failed to assemble a contractile ring and contract the cleavage furrow due to a defect in Rho and Rho-GEF localization to the division site. Plk1 inhibition did not affect anaphase A chromosome to pole movement but blocked anaphase B spindle elongation. Anaphase B is thought to result from the coordinated activities of microtubule-sliding motors that drive the poles further apart and changes in spindle microtubule dynamics. Plk1 is unlikely to control anaphase B through regulation of a spindle kinesin because inhibition of known motor proteins failed to recapitulate the Plk1 depletion phenotype. Instead, Plk1 inhibition caused a significant decrease in microtubule growth rate during metaphase and early anaphase, indicating a role for Plk1 in regulating microtubule dynamics. Consistent with an inhibition of microtubule growth rate, Plk1 inhibition reduced the rate of poleward microtubule flux in metaphase spindles and caused a reduction in metaphase spindle length that could be reversed by microtubule stabilization with taxol. These data suggest a model in which Plk1 accelerates microtubule growth during mitosis to maintain spindle length and drive anaphase B spindle elongation.

Keywords: Biochemistry
Advisor: Straight Aaron
Herschlag Daniel advisor. Thesis advisor
Theriot Julie advisor. Thesis advisor
China's Foreign Exchange Reserves: Balancing Consumption with Investments in Treasury Bonds and Sovereign Funds

Economists have long been curious about China’s conservatism with regard to managing its foreign exchange reserves, which exceeded the $2 trillion mark in early 2009. Usually, having more funds means that one can afford to take more risk, but China has managed its huge foreign exchange reserves cautiously, hoarding much of its reserves in relatively safe, but low-yield Treasury bonds, while investing only a small fraction into sovereign wealth funds, whose expected returns are more promising, but riskier. This has led many economists to conclude that China has managed its reserves sub-optimally. But by conducting simulations, I quantify the nature of China’s dual challenge of achieving decent investment returns while maintaining optimal consumption levels. These simulations are based on previous analyses of university endowments, which share some key similarities with China’s foreign exchange reserves. The results suggest that China may be vulnerable to short-term and long-term negative shocks to its foreign exchange reserves. In the end, I conclude that owing to its need to minimize risk, China’s conservative approach to managing its reserves, although counterintuitive to many economists, is fundamentally rational.

Keywords:  Department of Economics
Stanford Department of Economics
asset allocation
consumption
foreign exchange reserves
optimization
sovereign wealth funds
Thesis
Advisor: Shoven John
Default Options and Non-Standard 401(K) Choice

As policy makers search for ways to boost savings rates, automatic enrollment 401(k) plans are gaining popularity among employers in the United States. Such plans enroll new hires into default 401(k) funds at a default contribution rate with the option to opt out. The growing field of Behavioral Economics, meanwhile, has begun to incorporate framing effects such as default options into economic modeling. These effects have important implications for public policy. This paper presents a model of 401(k) choice that accounts for non-standard responses to default contribution rates. The parameters of this model are estimated using maximum likelihood estimation. To infer the policy implications of the model, this paper adopts a generalized normative framework that defines welfare in terms of choice. The observed data generate a parameterization that is consistent with the notion that defaults influence contribution rates through both anchoring bias and status quo bias. Moreover, welfare gains from automatic enrollment may not be as large as previously thought.

Keywords:  Department of Economics
Stanford Department of Economics
behavioral
retirement
anchor
status quo
choice-based
framing
Thesis
Advisor: Bernheim B. Douglas
The design and implementation of dynamic information flow tracking systems for software security [electronic resource]

Computer security is in a crisis. Attackers are exploiting an ever-increasing range of software vulnerabilities in critical public and private sector computer systems for massive financial gain Recent research has established Dynamic Information Flow Tracking (DIFT) as a promising platform for detecting a wide range of security attacks. The idea behind DIFT is to tag (taint) untrusted data and track its propagation at byte or word-granularity through the system to prevent security attacks. This dissertation presents novel DIFT platforms and policies to address real-world server-side vulnerabilities, in both low-level and high-level code. We show that well-designed DIFT platforms and policies can comprehensively prevent the major server-side security vulnerabilities with little to no performance overhead and without requiring application source code access or debugging information. We describe novel DIFT policies for comprehensively preventing software vulnerabilities. We also present novel hardware and software DIFT platforms for executing these policies. We then demonstrate the effectiveness of our policies and platforms by preventing a wide range of real-world software vulnerabilities, from operating system buffer overflows in the Linux kernel to authentication bypass in PHP web applications. Unlike prior security techniques, DIFT can be fast, safe, practical, and flexible. We present Raksha, the first flexible hardware DIFT platform, which provides flexibility and safety while maintaining the practicality and performance benefits of traditional hardware DIFT designs. Raksha supports flexible, hardware-enforced DIFT policies using software-controlled tag policy registers. We demonstrate the Raksha design using an FPGA-based prototype system, and prevent a wide range of attacks on unmodified application binaries. We also use Raksha to develop a novel DIFT policy for robustly preventing buffer overflows. Our policy is the first comprehensive DIFT policy for buffer overflow prevention to support large, real-world applications and even the operating system without observed real-world false positives. We demonstrate our buffer overflow policy using the Raksha prototype, and prevent buffer overflows in both userspace applications and the Linux kernel. We also developed Nemesis, a DIFT-aware PHP interpreter, which was the first system for comprehensively preventing authentication and authorization bypass attacks in web applications. Nemesis uses a novel application of DIFT to automatically infer when a web application has correctly and safely authenticated a web client. We demonstrate the effectiveness of Nemesis by preventing authentication and authorization bypass vulnerabilities in real-world PHP web applications.

Advisor: Kozyrakis Christoforos
Lam Monica S. advisor. Thesis advisor
Mazières David (David Folkman)
Developing Iraq’s Oil Industry to Maximize Government Net Revenues

This paper seeks to determine whether (1) nationalizing Iraq’s oil industry or (2) developing it through production-sharing agreements with international oil companies (IOCs) will generate the highest amount of net revenues for the Iraqi government. I propose to use the development of the Majnoon oil field in southern Iraq as a case study to answer this question. I consider a timeframe of forty years and construct the estimated revenues and costs associated with developing Majnoon under nationalization, comparing them to those associated with developing Majnoon under a PSA similar to that employed in Oman. I conclude that if the Iraqis believe that the Iraq National Oil Company (INOC) can be at least 87.5% as efficient as an IOC, then Majnoon would be more profitable under nationalization. If the INOC cannot be at least 75% as efficient, then Majnoon would be more profitable under a PSA. If the INOC’s relative efficiency is between 75%-87.5% (deemed the “Indecision Interval”), then Iraqi decision-makers must engage in further analysis to determine the profit-maximizing option. The case of Majnoon provides insights important for the decision-makers to consider when deciding on whether to nationalize Iraq’s oil industry or not.

Keywords:  Department of Economics
Stanford Department of Economics
Iraq
oil
Majnoon
international oil company
Iraq National Oil Company
Thesis
Advisor: Rothwell Geoffrey
Dynamic programming and its application in economics and finance [electronic resource]

Multistage decision problems are numerically challenging. Typically the work to solve such problems is an exponential function with respect to both the number of stages and the number of decision parameters. The problems have been researched extensively and a wide variety of methods to solve them have been proposed. Inevitably all methods are limited in the size of problem they can solve. The purpose of our work is to develop a new more efficient algorithm and one that can run on parallel architectures, thereby extending significantly the size of problems that are tractable. We present a numerical dynamic programming algorithm that has three components: optimization, approximation, and integration. A key feature of the approximation methods we use is to preserve mathematical features such as convexity and differentiability, which enables us to use powerful optimization methods. To illustrate the efficiency of the new method we present extensive results on optimal growth models and dynamic portfolio problems, using our implementation of the algorithm on the Condor Master-Worker system.

Advisor: Judd Kenneth L.
Murray Walter primary advisor. Thesis advisor
Saunders Michael A. advisor. Thesis advisor
Dynamics for network formation games [electronic resource]

Modern communication networks operate at a scale that makes the use of centralized policies/protocols challenging. At the same time, nodes in the network are self-interested strategic agents. It is therefore natural to model the formation of modern communication networks as the result of interactions between self-interested agents; and to consider the observed networks as its equilibrium outcomes. The aim of such modeling is to predict some macroscopic observable, here efficiency. If we want to make the best prediction possible, how should one model the strategic interactions of the agents, and what equilibrium concept should be used? In this thesis, we assume the network is the outcome of a network formation game. The network formation game considered captures two conflicting objectives of self-interested nodes in a network. On one hand, such a node wishes to be able to reach all other nodes in the network; on the other hand, it wishes to minimize its cost of participation. We focus on myopic local best response dynamics for such games, where nodes can only deviate to form links with others in a restricted neighborhood. For two general classes of costs of participating in the network, we show that a static analysis of the network formation game does not provide useful predictions about efficiency. To do so, we identify extrema outcomes, with respect to efficiency, in the equilibrium set and show they correspond to the extrema of all reasonable outcomes. In some cases, this holds true even when using strong stability as equilibrium concept. In terms of efficiency loss, we show the efficiency loss can be linear in the number of nodes. We then show that, for myopic local best response dynamics, if we allow a single node a "one step look-ahead'', the dynamics converge almost surely, and the efficiency loss can be constant. In some cases, our dynamics converge to efficient outcomes. Thus the prediction about efficiency can be as precise as possible, with one unique value predicted, and full efficiency achieved.

Advisor: Johari Ramesh
Jackson Matthew O. advisor. Thesis advisor
Mannor Shie advisor. Thesis advisor