VictorJuiz/thesis huggingface dataset:
Three essays on the diffusion of clean energy technologies [electronic resource]

Due to the pressing challenges from climate change and energy security, clean energy technologies have been widely regarded as providing important channels to reduce carbon emissions and to alleviate the reliance on fossil fuels. It is imperative to analyze the underlying dynamics and mechanisms of the diffusion of clean energy technologies, to identify key factors influencing the diffusion and to evaluate the impacts from the diffusion process. This dissertation empirically analyzes the diffusion of wind energy and energy efficient building technologies, using China and U.S. as examples. Chapter 1 introduces clean energy technologies as well as the key mechanisms, entities and issues involved in the diffusion of these technologies. Chapter 2 quantifies the effect of technology acquisition mechanisms -- purchasing production licenses from foreign manufacturers, joint design with foreign design firms, joint ventures and domestic R& D -- on wind turbine manufacturers 's technology levels (as measured by turbine size, in MW). It also examines the impacts of government policies and manufacturers' business diversification on technology levels. The results from econometric modeling studies indicate that technology acquisition mechanisms are statistically significant factors in influencing both technology upgrading and catch-up. In Chapter 3, learning by doing and learning by searching rates of wind energy in China are quantified. The two types of learning investigated are associated with about 4% price reduction per doubling of installed capacity, providing an estimate of the evolution of the price of wind power, a technology widely used in other markets, which in China has benefited from technology leapfrogging, established supply chains, and operational experience in other countries. This chapter also identifies that wind turbine manufacturing localization and wind farm economies of scale are significantly associated with reductions in the price of wind power in China. Chapter 4 discusses the rebound effects of energy efficiency. A key ongoing debate on energy efficiency is about the extent of the rebound effects: does greater efficiency lead to higher or lower energy use than there would have been without those improvements? Chapter 4 analyzes the rebound effects of energy efficiency in the commercial building sector. Chapter 4 builds a structural model of a building's decision to adopt an energy efficient building technology and subsequent energy demand. The results show that energy efficient technologies save energy after rebound effects. This gives quantitative argument for government to promote the diffusion of energy efficient technologies.

Advisor: Ortolano Leonard primary advisor. Thesis advisor
Sweeney James L. primary advisor. Thesis advisor
Harding Matthew C. advisor. Thesis advisor
Tie-simplex method for thermal-compositional simulation [electronic resource]

Enhanced Oil Recovery (EOR) processes usually involve complex phase behaviors between the injected fluid (e.g., steam, hydrocarbon gas, CO2) and the in-situ rock-fluid system. Equation-of-State (EoS) computations for complex mixtures than can form three, or more, phases at equilibrium pose significant challenges. In addition, issues related to proper coupling of the thermodynamic phase-behavior with multi-component transport across multiple fluid phases must be resolved in order to model the behaviors of large-scale EOR processes accurately and efficiently. Here, we propose an EoS-based tie-simplex framework to deal with the thermodynamic phase behavior, in which an arbitrary number of phases can form. It is shown that our generalized negative-flash method yields the unique tie-simplex parameterization of the compositional space. Specifically, we show that the tie-simplexes change continuously as a function of temperature, pressure, and composition. In the course of a thermal-compositional simulation, the compositional space is tabulated adaptively using tie-simplexes. We also prove that the Gibbs free-energy analysis of this tie-simplex space is equivalent to conventional methods for equilibrium phase calculations. This multiphase tie-simplex method is integrated into Stanford's General-Purpose Research Simulator (GPRS), and its application to thermal-compositional simulation is demonstrated here using several challenging thermal-compositional flows with complex phase behaviors.

Keywords: Energy Resources Engineering
Advisor: Tchelepi Hamdi primary advisor. Thesis advisor
Orr F. M.
Voskov Denis advisor. Thesis advisor
A tiling DNA microarray approach for functional gene analyses in microbial ecosystems [electronic resource]

I have developed a novel and broad-ranging approach to the characterization of complex microbial communities by analyzing the abundance and expression of key functional genes. The method is based on a tiling oligonucleotide DNA microarray, implementing an unprecedented number of probes per gene by tiling probe sequences across genes of interest at 1X--2X coverage. This design favors the avoidance of false positive gene identification in samples of DNA or RNA extracted from complex microbial communities. I have implemented this method using hydrogenase genes to investigate anaerobic microbial communities where H2 is an important intermediate (the Hydrogenase Chip), reductive dehalogenase genes to investigate ecosystems containing organohalide-respiring microorganisms (the Reductive Dehalogenase Chip), and the genome of the colorless sulfur bacterium Thiovulum to study its in-situ gene expression (the Thiovulum Chip). The Hydrogenase Chip revealed key organohalide-respiring and sulfate-reducing microorganisms in laboratory microcosms that simulate the bioremediation of tetrachloroethene and identified Microcoleus chthonoplastes as a key H2-producing microbe in phototrophic microbial mats. The Reductive Dehalogenase Chip revealed population dynamics of the organohalide-respiring strains present in a long-term laboratory microcosm to an unprecedented level of detail, and showed that different Dehalococcoides strains may differ in their sensitivity to hydrogen sulfide. Experiments with the Thiovulum Chip were ultimately unsuccessful, but revealed mRNA degradation that correlated with secondary structure stability in a way that was informative for future environmental transcriptomic experiments. Independent quantitative PCR analysis on selected hydrogenase genes showed that the tiling DNA microarray approach is semiquantitative. We also determined that as microbial community complexity increases, specificity must be traded for sensitivity in analyzing data from tiling DNA microarrays. This work on a range of questions in different ecosystems has determined the necessary conditions for the successful implementation of the tiling DNA microarray approach.

Advisor: Spormann Alfred M. primary advisor. Thesis advisor
Francis Christopher advisor. Thesis advisor
Huang Kerwyn Casey
Topics in sparse multivariate statistics [electronic resource]

In this thesis, we visit three topics in modern sparse multivariate analysis that has received and still continues to receive significant interest in applied statistics in recent years: (a) Sparse high dimensional regression (This work appears in our paper Mazumder et al 2010.); (b) Low-rank matrix completion \& collaborative filtering (This work appears in our paper Mazumder et al 2011) and (c) Sparse undirected gaussian graphical models. (This work appears in our papers Mazumder and Hastie 2012 and Mazumder and Hastie 2011). A main challenge in high dimensional multivariate analysis is in developing scalable and efficient algorithms for large scale problems that naturally arise in scientific and industrial applications. This thesis explores the computational challenges that arise in these problems. We develop and analyze statistically motivated algorithms for various models arising in the aforementioned areas. This enhances our understanding of algorithms, sheds novel insights on the statistical problems and leads to computational strategies that appear to outperform state of the art. A salient feature of this work lies in the exchange of ideas and machinery across the fields of statistics, machine learning, (convex) optimization and numerical linear algebra.

Keywords: Statistics
Advisor: Hastie Trevor primary advisor. Thesis advisor
Friedman Jerome
Tibshirani Robert advisor. Thesis advisor
The topology of spaces of J-holomorphic maps to CP² [electronic resource]

In [Seg79], Graeme Segal proved that the space of holomorphic maps from a Riemann surface to a complex projective space is homology equivalent to the corresponding continuous mapping space through a range of dimensions increasing with degree. I will address if a similar result holds when other almost complex structures are put on projective space. For any compatible almost complex structure J on CP^2, I prove that the inclusion map from the space of J-holomorphic maps to the space of continuous maps induces a homology surjection through a range of dimensions tending to infinity with degree. The proof involves comparing the scanning map of topological chiral homology ([Sal01], [Lur09], [And10]) with gluing of J-holomorphic curves ([MS94], [Sik03]).

Keywords: Mathematics
Advisor: Cohen Ralph L.
Galatius Søren
Ionel Eleny advisor. Thesis advisor
Towards a holographic framework for cosmology [electronic resource]

Studies on black hole physics have lead to the holographic principle, which states that a quantum gravitational system can be captured by a theory living in fewer dimensions. Given the observed accelerating expansion of our universe, it has been a major challenge to understand the realization of the holographic principle in cosmology. In this dissertation we review our progress in building such a framework. Starting from concrete AdS/CFT dual pairs, we obtain de Sitter and other general FRW solutions by adding branes and other ingredients from string theory. In the de Sitter case, our brane construction gives a microscopic realization of the dS/dS correspondence. The degrees of freedom in the semi-holographic dual theory provide a parametric interpretation of the Gibbons-Harking entropy of the bulk de Sitter space. In the FRW case, we focus on a family of simple FRW solutions sourced by magnetic flavor branes. These solutions have a holographic dual interpretation which decouples from gravity at late time, opening up the possibility of a precise duality. Time-dependent effects play a crucial role in these dual theories. In particular, we find that time-dependent couplings in a quantum field theory can strongly affect long-distance physics, effectively shifting the infrared operator dimensions and generalizing known unitarity bounds.

Keywords: Physics
Advisor: Silverstein Eva
Kachru Shamit
Susskind Leonard advisor. Thesis advisor
Towards a precise theory of cosmology [electronic resource]

In this thesis I discuss progress towards a precise mathematical description of cosmology and in particular of eternal inflation. I present a conjecture for a necessary condition for a spacetime to have a precise dual description, discuss how the dictionary of dS/CFT is more sophisticated than that of AdS/CFT, present a soluble model of eternal inflation that has a conformal boundary theory at future infinity, and discuss the implications of this model for a conjectured precise dual theory based on observers in bubbles with zero cosmological constant. The work described was done in collaboration with Leonard Susskind, Douglas Stanford, and Stephen Shenker.

Keywords: Physics
Advisor: Susskind Leonard primary advisor. Thesis advisor
Dimopoulos Savas
Shenker Stephen Hart
Towards clinically relevant neural prostheses [electronic resource]

Neural prostheses translate signals from the brain into useful control signals, manipulating end-effectors such as computer cursors or robotic arms. Their aim is to offer greater interaction with the world for patients suffering from limb dysfunction due to spinal cord injury, neurodegenerative disease, and other conditions leading to limb paralysis. Prior intracortical electrode neural prosthesis studies have demonstrated compelling proof-of-concept systems, but barriers to successful clinical translation still remain, such as performance and robustness. Measures of performance include the speed, accuracy, and bitrate of the system. Robustness refers to the sustained performance of the system within a day and across days. The work presented here demonstrates algorithms and advances for neural prostheses that increase both performance and robustness. The recalibrated feedback intention trained Kalman filter (ReFIT-KF) increased performance by at least twofold compared to previously reported decoders, approaching the speed of natural arm movements. It achieved bitrates of up to 4.5 bits per second (bps) and communication rates of up to 10 words per minute (wpm) when used on a typing task. These results were reliable and repeatable for hours at a time across 4 array-years between two subjects. Utilizing neural spike threshold crossings as a signal source, the ReFIT-KF algorithm also demonstrated sustainable performance without any changes to decoder weights for one year with a degradation rate of 0.05 bps per month. Performance further increased when the ReFIT-KF was combined with an HMM state decoder for the detection of clicks, eliminating the need for hold periods. This combined ReFIT-KF and HMM decoder achieved bitrates of up to 6.5 bps and 15 wpm. Taken together, these findings may help advance neural prostheses closer to clinical viability.

Keywords: Bioengineering.
Advisor: Shenoy Krishna V. (Krishna Vaughn) primary advisor. Thesis advisor
Boahen Kwabena (Kwabena Adu) advisor. Thesis advisor
Henderson Jaimie (Jaimie M.)
Towards monolithic semiconductor photonic crystal passively mode locked laser for two-photon microscopy [electronic resource]

Semiconductor Monolithic Passively Mode Locked Lasers (MMLLs) have been demonstrated and have a variety of applications including sensing, in optical communications and optical clock generation. The major advantage that these semiconductor light sources possess is their compact size, high efficiency, low cost and robustness. Also the ability to access different wavelengths using various semiconductor materials is a big advantage. The inability to get these lasers to operate at low repetition rates and the limited peak output power of the pulses are the two major limitations of these lasers. The repetition rate is inversely proportional to the semiconductor laser cavity length. The lowest repetition rate in current MMLLs is around 1GHz. This rate is limited by the complexity involved in the fabrication of centimeter long semiconductor laser cavities. The material loss, dispersion and carrier radiative recombination lifetime also limit the output repetition rate. Lower repetition rate lasers can be used in low frequency integrated optical circuits and also for imaging especially for Two-Photon Microscopy (TPM). TPM works by exciting florescence dyes using two photons instead of one. This requires pulsed lasers with high peak power and high energy per pulse. TPM is currently done by using expensive and bulky Ti:Sapphire mode locked lasers that can produce subpicosecond pulses at a repetition rate of order of 100 MHz. The possible use of semiconductor lasers for this application can transform this field by dramatically reducing the cost of imaging and allowing for dramatically smaller sized and more mobile imaging solutions. One potential way to reduce the repetition rate of the lasers without increasing the physical cavity length is to incorporate a slow light photonic crystal structure inside the lasers cavity. Such a laser cavity will have a group index that is much larger than the material refractive index thereby giving a longer optical path length for the same physical length of the device. The incorporation of the photonic crystal will also allow the possibility to do dispersion engineering within the laser cavity and to enable pulse compression. Both these effects can increase the two-photon excitation efficiency for TPM. In this work we highlight the design and progress towards the development of a monolithic semiconductor photonic crystal passively mode locked laser for two-photon microscopy.

Keywords: Electrical Engineering
Advisor: Harris J. S. (James Stewart)
Fan Shanhui
Schnitzer Mark Jacob
Towards solid-state quantum repeaters [electronic resource] : ultrafast coherent optical control and spin-photon entanglement in charged InAs quantum dots

This work elaborates on previously established all-optical coherent control techniques of individual InAs quantum dot electron spins, and demonstrates proof-of-principle experiments that should allow the utilization of such quantum dots for future, large-scale quantum repeaters. First, we show how more elaborate, multipulse spin control sequences can markedly increase the fidelity of the individual spin control operations, thereby allowing many more such operations to be concatenated before decoherence destroys the quantum memory. Furthermore, we implemented an ultrafast, gated version of a di erent type of control operation, the so-called geometric phase gate, which is at the basis of many proposals for scalable, multi-qubit gate operations. Next, we realized a new type of quantum memory, based on the optical control of a single hole (pseudo-)spin, that was shown to overcome some of the detrimental e ects of nuclear spin hyper fine interactions, which are assumed to be the predominant sources of decoherence in electron spin-based quantum memories - at the expense, however, of a larger sensitivity to electric field-related noise sources. Finally, we discuss a system-level experiment where the quantum dot electron spin is shown to be entangled with the polarization of a spontaneously emitted photon after ultrafast, time-resolved (few picoseconds) downconversion to a wavelength (1560 nm) that is compatible with low-loss optical fi ber technology. The results of this experiment are two-fold: on the one hand, the spin-photon entanglement provides the necessary light-matter interface for entangling remote memory qubits; on the other hand, the transfer to a low- fiber-loss wavelength enables a signi cant increase in the potential distance range over which such remote entanglement could be established. Together, these two aspects can be seen as a necessary preamble for a future quantum repeater system.

Keywords: Electrical Engineering
Advisor: Yamamoto Yoshihisa primary advisor. Thesis advisor
Brongersma Mark L. advisor. Thesis advisor
Vuckovic Jelena advisor. Thesis advisor
Tragic ugliness [electronic resource] : the interplay of genre and aesthetics in Greek drama

This dissertation investigates the aesthetics of Greek tragedy in comparison with those of Old Comedy through a study of the ugly objects visually represented in each genre. Arguing against the received opposition of beautiful tragedy and ugly comedy, the dissertation concludes that tragic ugliness is essentially painful, visually eliciting the genre's characteristic emotions of pity and fear. The first chapter begins with Aristotle's foundational Poetics to establish a historically informed framework with which to work upon classical Greek notions of ugliness in drama. This chapter considers two passages implicitly relevant to tragic spectacle pertaining to genre, aesthetics, form, costume, and mimesis. The chapter suggests that Aristotle sets up an implicit generic taxonomy in Poetics according to which a subset of tragedy, a genre he tends to describe in ennobling terms, may be considered painfully ugly. The second chapter observes that, in contrast with those in other genres, tragic characters are rarely described as beautiful or ugly and that, as a result, tragic aesthetics are determined largely through theatrical costume. The chapter focuses in particular on rags, inherently formless garments that visually represent past sufferings and often code for bodily deformity. A case study of Xerxes' arrival in rags in Aeschylus' Persians demonstrates the importance of rags from our earliest tragedy. The third chapter uses the guest-appearance of tragic rags in Old Comedy to chart the aesthetic boundaries between the two genres. It demonstrates how Aristophanes exploited the formlessness of rags, allowing those garments alone among all tragic costumes to be imported into the ugly world of comedy without the burlesque distortion typical of comic paratragedy. The chapter offers a production analysis of a crucial scene from Acharnians, making the novel argument that the very same material costumes from Euripidean productions may have been recycled in Acharnians, implicit material proof of the rags' ugliness. The final chapter situates the aesthetics of tragic corpses within and outside of artistic representation. While living, tragic characters are rarely considered aesthetically, but as corpses their bodies become supreme objects of tragic spectacle with generic and mimetic implications.

Keywords: Classics
Advisor: Martin Richard P. primary advisor. Thesis advisor
Peponi Anastasia-Erasmia primary advisor. Thesis advisor
Nightingale Andrea Wilson advisor. Thesis advisor
Rehm Rush advisor. Thesis advisor
A trajectory optimization method for close range surveys of non-planar surfaces [electronic resource]

This thesis develops a trajectory optimization method for underwater robotic vehicles performing close range visual surveys of a surface. The work in this thesis is motivated by the problem of acquiring high-quality imagery of the ocean floor. The method described herein enables the systematic tradeoff of competing survey objectives, and also enables motion-constrained survey vehicles to use prior terrain data to anticipate upcoming terrain changes. In general, visual survey missions trade off image quality for trajectory smoothness. Due to light's limited penetration through water, the terrain is typically only visible within a few meters of the sea floor. Furthermore, the highest image quality occurs when the camera is pointed perpendicular to the terrain and when the camera maintains a constant altitude over the terrain. However, if a smooth trajectory is desired over rough non-planar terrain, perpendicularity and altitude uniformity must be sacrificed. No previous work has developed a systematic way of performing this tradeoff. Survey trajectories are generated by specifying a trajectory smoothness constraint, then optimally planning trajectories that maximize perpendicularity and altitude performance under the constraint. Trajectories are planned over a B-spline surface that is fit optimally to a bathymetric map of the survey area. The fitting occurs by mapping the trajectory smoothness constraint to geometric constraints on the B-spline, then solving a newly posed nonlinear constrained optimization problem. Results that compare the performance of the optimally generated trajectories against previous visual survey methods are presented. Results in the field validate the use of the method to survey sections of ocean floor in Monterey Bay, CA.

Keywords: Aeronautics and Astronautics
Advisor: Rock Stephen M. primary advisor. Thesis advisor
Alonso Juan José
Enge Per advisor. Thesis advisor