VictorJuiz/thesis huggingface dataset:
Impact of nominal signal deformations on satellite navigation systems [electronic resource]

Global Navigation Satellite Systems (GNSS), of which GPS is the standard-bearer, are ubiquitous and widely used in various applications including aviation, agriculture, automobile navigation, search and rescue, and recreation. GNSS are steadily being improved with the addition of new constellations, new frequencies, and new signals. Future multi-frequency GNSS will eliminate one of the largest error sources (ionosphere) and promises even better performance: improving accuracy from approximately 5 meters to 1 meter. Unfortunately, the new frequencies and signals will have small but unavoidable biases relative to one another. The impact of these biases increases as other error sources are eliminated. Nominal satellite signal deformations -- deviations of broadcast GPS satellite signals from ideal -- result in tracking errors, range biases, and position errors in GPS receivers. It is thus imperative that these errors are quantified, to enable the design of appropriate error budgets and mitigation strategies for various application fields. Traditional measurement methods for these signal deformations can be broadly classified into two categories. The first category uses large antenna dishes paired with high-resolution, high-bandwidth measurements and is limited to short time intervals (seconds) due to data storage constraints. However, these measurements could be subject to time-varying effects that are unobservable between data sets. The second category uses lower-resolution, lower bandwidth measurements over long continuous time periods, but less effectively attenuates error sources such as multipath that obscure the signal deformations of interest. The major contribution in this dissertation is the development of an innovative measurement method that combines the merits of both past approaches while mitigating the disadvantages, rendering nominal signal deformations measurable. Furthermore, these measurements were repeatable over long time periods of hours, days, and months. A good estimate of the position error impact on user receivers could be obtained using these highly consistent measurements. A mitigation strategy was developed in response and verified using this measurement method. The results show that the position error impact could be substantial, but could also be effectively mitigated with the use of an appropriate mitigation strategy. This work is a critical component toward the successful implementation of future dual-frequency GNSS-based landing systems for aviation.

Keywords: Electrical Engineering.
Advisor: Enge Per
Kahn Joseph M. (Joseph Mardell) advisor. Thesis advisor
Walter Todd
Implicit and higher-order discretization methods for compressible multi-phase fluid and fluid-structure problems [electronic resource]

This thesis describes an embedded boundary framework for multi-phase flow and fluid-structure interaction. This is based on the FIVER method, first introduced in (Farhat, 2008). This framework is capable of handling complex, evolving material interfaces, including structural fracture. This thesis makes a variety of contributions. Among the major contributions are an implicit time stepping method for embedded boundaries with highly nonlinear physical phenomena, which is shown to be up to 40x faster than the corresponding explicit time stepping scheme. Also, a multigrid method for the FIVER embedded boundary method is presented, which enables the solution of steady flow problems nearly 12x faster than a standard Newton-Krylov time stepping scheme. Then a second order extension of FIVER is introduced for multi-fluid and fluid-structure interaction problems. Finally, the stability and accuracy properties of this extension are analyzed.

Advisor: Farhat Charbel primary advisor. Thesis advisor
Banks Jeffrey
Lew Adrian advisor. Thesis advisor
The importance of linguistic and non-linguistic context in early language understanding and word learning [electronic resource]

In this dissertation, I propose that some of the mechanisms used by adults to resolve ambiguity in sentence processing might also be exploited by children to interpret language and resolve referential ambiguity in word learning. I present the findings of four studies focusing on how young children make use of words other than labels (i.e., the semantic context of sentences) to help disambiguate the referent of familiar and novel words. In Study 1, 30-month-olds were able to use their knowledge about verbs and actions to rapidly determine the objects a speaker was talking about, even when these objects were unfamiliar. In addition to determining the objects being talked about, children took advantage of these opportunities to map two novel words to two unfamiliar objects, and they remembered these mapping for over a week. Moreover, children's memory for the object names was related both to their vocabulary skill and to their proficiency in establishing reference incrementally based on information at the verb. In Study 2, children used their knowledge about familiar objects and the locations in which they typically appear to rapidly establish reference. Children's proficiency in making this kind of inference was related to their vocabulary skills. In Study 3, children combined their knowledge about the names of locations and the names of objects to interpret complex spoken sentences, guiding their attention to an object even before it was named. Children's predictive listening was again related to their vocabulary skills. In Study 4, children used their knowledge about locations to rapidly guide their attention to objects in their environment, even when the objects were unfamiliar. And again, children took advantage of these opportunities to map novel words to the unfamiliar objects. As in Study 1, children's ability to remember the names of the unfamiliar objects was related to their proficiency in establishing reference based on the names of locations. These studies show that words other than object names can guide children's attention to familiar or novel objects, providing opportunities to create or strengthen connections between words and objects.

Keywords: Psychology.
Advisor: Fernald Anne
Frank Michael C. (Professor of human biology) advisor. Thesis advisor
Markman Ellen M.
Improving datacenter network performance with multicast [electronic resource]

The network constitutes a significant portion of a datacenter's cost and its performance is critical to scaling datacenter applications. Datacenter operators thus strive to efficiently utilize network resources, while providing high, predictable network performance for applications. Recent trends in large-scale data storage and processing result in increasingly more data replicated within a datacenter for parallel access and fault tolerance. State-of-the-art systems employ unicast-based replication, which uses network bandwidth inefficiently. IP multicast enables data replication within the network at line rate. However, IP multicast is not congestion controlled, and therefore is incompatible with the dominant datacenter transport, TCP. In this thesis, I investigate an enhancement to TCP --- Congestion-controlled Single-source Multicast Optimization (TCP-COSMO). TCP-COSMO adds support for multicast transmissions to TCP, while congestion controlling multicast flows at high line rate (10Gbps). I show that, with multicast replication, one can scale distributed storage system read/write rates linearly with offered load, and reduce tail write latency by up to two orders of magnitude compared to to existing unicast-based replication schemes. I extend TCP-COSMO to support queue-aware congestion control algorithms like Datacenter TCP. This allows running throughput-oriented multicast flows without degrading the performance of concurrent, short-lived latency-sensitive flows. I further present PredNet, which integrates multicast into systems that provide bandwidth guarantees in datacenters. With bandwidth guarantees, I demonstrate predictable multicast transfer times and rapid convergence of bandwidth shares among competing sets of flows. Furthermore, I study multipath multicast forwarding for leaf-spine datacenter networks. I show that multipath forwarding enables multicast packet replication in the spine layer without causing extra congestion. I also leverage the network topology to scale the effective capacity of limited hardware multicast forwarding state. I show that distributed storage systems can scale to tens of thousands of servers participating in multicast write replication without exhausting multicast forwarding state in switches.

Advisor: Cheriton David R. primary advisor. Thesis advisor
McKeown Nick advisor. Thesis advisor
Rosenblum Mendel advisor. Thesis advisor
Improving fiber optic gyroscope performance using a single-frequency laser [electronic resource]

The fiber optic gyroscope has become the most commercially successful fiber sensor to date and has been deployed in a variety of applications requiring high sensitivity, low noise measurements of rotation rate. Yet despite this success, traditional broadband source-driven gyroscopes have failed to reach their ultimate potential as the primary rotation sensors for inertial navigation applications -- such as guidance in airplanes and ships -- being passed over in favor of more costly and relatively more complicated technologies. Achieving the performance levels necessary for these demanding applications using a broadband source has proven challenging. To overcome these challenges, we propose a simple but significant alteration to the standard gyroscope configuration: replace the traditional broadband source with a single-frequency laser. While initial experimental work on fiber optic gyroscopes employed laser sources, researchers quickly abandoned this approach following the discovery that a broadband source could mitigate the deleterious effects of fiber backscattering, as well as polarization and nonlinear effects. As a result, a thorough analysis of these effects was never carried out. We present a more robust analysis with particular focus on backscattering and show that the induced noise and drift in a laser-driven gyroscope can meet navigation-grade requirements. Achieving this improvement requires careful selection of the laser linewidth and phase modulation scheme. These performance gains comes with the added benefit that a laser-driven gyroscope does not suffer from source beating noise and high scale factor instability, two limiting factors for broadband source-driven gyroscopes. We present experimental results that verify our theoretical predictions and compare the experimental performance of our laser-driven gyroscope with a broadband source-driven gyroscope.

Keywords: Electrical Engineering.
Advisor: Fan Shanhui
Digonnet Michel J. F. advisor. Thesis advisor
Solgaard Olav advisor. Thesis advisor
Inclusive search strategies and bottom-up approaches for new physics at colliders [electronic resource]

The first run of the Large Hadron Collider (LHC) has strongly challenged our view of new physics by tightly constraining the most investigated scenarios such as super- symmetry. If new physics is within the reach of future experiments, discovering it will require devising new data analysis techniques and considering new approaches to open issues such as the fine-tuning problem. This thesis discusses how to elaborate new search strategies using signature-based --bottom-up-- approaches. It focuses in particular on multijet LHC signatures, the fine-tuning problem, dark matter detection and explaining non-standards Higgs couplings.

Keywords: Physics.
Advisor: Wacker Jay primary advisor. Thesis advisor
Hewett JoAnne L. advisor. Thesis advisor
Schwartzman Ariel G.
Inference and estimation in high-dimensional data analysis [electronic resource]

Modern technologies generate vast amounts of fine-grained data at an unprecedented speed. Nowadays, high-dimensional data, where the number of variables is much larger than the sample size, occur in many applications, such as healthcare, social networks, and recommendation systems, among others. The ubiquitous interest in these applications has spurred remarkable progress in the area of high-dimensional data analysis in terms of point estimation and computation. However, one of the fundamental inference task, namely quantifying uncertainty or assessing statistical significance, is still in its infancy for such models. In the first part of this dissertation, we present efficient procedures and corresponding theory for constructing classical uncertainty measures like confidence intervals and p-values for single regression coefficients in high-dimensional settings. In the second part, we study the compressed sensing reconstruction problem, a well-known example of estimation in high-dimensional settings. We propose a new approach to this problem that is drastically different from the classical wisdom in this area. Our construction of the sensing matrix is inspired by the idea of spatial coupling in coding theory and similar ideas in statistical physics. For reconstruction, we use an approximate message passing algorithm. This is an iterative algorithm that takes advantage of the statistical properties of the problem to improve convergence rate. Finally, we prove that our method can effectively solve the reconstruction problem at (information-theoretically) optimal undersampling rate and show its robustness to measurement noise.

Keywords: Electrical Engineering.
Advisor: Montanari Andrea primary advisor. Thesis advisor
Taylor Jonathan
Tse David advisor. Thesis advisor
Inference for correlation-based hierarchical clustering of variables [electronic resource]

In this dissertation, we consider the clustering of variables based on their pairwise absolute sample correlations, with a focus on hierarchical clustering procedures. While these procedures have existed for quite some time, statistical guarantees on the resulting clusters of variables are not available. We construct test statistics and corresponding null distributions for each merge in the clustering tree. We develop new multiple testing procedures to combine these stepwise results into an adaptive cutting procedure to select a set of clusters from the hierarchical tree and attach a statistical guarantee. As part of this work, we also develop new distributional results for the large order statistics of sample correlations between many spherically distributed variables.

Keywords: Statistics.
Advisor: Tibshirani Robert primary advisor. Thesis advisor
Hastie Trevor advisor. Thesis advisor
Taylor Jonathan
The influence of convergent margin structure on deep-water stratigraphic architecture, pore pressure evolution, and source rock maturation in the East Coast Basin, New Zealand [electronic resource]

The East Coast Basin of the North Island, New Zealand contains active petroleum systems and has been explored intermittently since the late 1800s. Despite a few small discoveries, the basin is non-commercial largely due to stratigraphic and structural complexities associated with its development on the Hikurangi convergent margin. The major petroleum system risks are the presence of reservoir rock and good potential, mature source rock. Additionally, high overpressures have caused significant drilling problems, representing both a financial burden and a safety hazard for exploration. This dissertation investigates the petroleum system elements and processes of the East Coast Basin, and outlines the importance of convergent margin structure on reservoir architecture, overpressure generation and distribution, and source rock maturation. Each of the three chapters addresses aspects of the petroleum system. Chapter 1 focuses on the reservoir rock though stratigraphic and architectural analysis of an outcropping deep-water turbidite deposit, representing a reservoir analog for the basin. Chapter 2 establishes the structural and stratigraphic framework for the basin through geologic time, providing a means to understand and predict the development of overpressure. Lastly, Chapter 3 assesses the source rock maturation in the East Coast Basin through evaluation of the paleo-basal heat flow and structurally-controlled burial history. This dissertation integrates data from a variety of disciplines (sedimentology, structure, geomechanics, geochemistry) and scales (well samples, well logs, outcrop, seismic data) in order to provide a robust basin analysis of the East Coast Basin.

Keywords: Geological and Environmental Sciences.
Advisor: Graham S. A. (Stephan Alan)
Scheirer Allegra Hosford advisor. Thesis advisor
Lowe Donald R.
Information theoretic results on exact distributed simulation and information extraction [electronic resource]

In the first part of the thesis we will introduce the notion of exact common information, which is the minimum description length of the common randomness needed for the exact distributed generation of two correlated random variables $(X, Y)$. We introduce the quantity $G(X; Y)=\min_{X\to W\to Y}H(W)$ as a natural bound on the exact common information. We then introduce the exact common information rate, which is the minimum description rate of the common randomness for the exact generation of correlated sources $(X, Y)$. We give a multiletter characterization for it as the limit $\Gbar(X; Y)=\lim_{n\to\infty}(1/n)G(X^n; Y^n)$. While in general $\bar{G}(X; Y)$ is greater than or equal to the Wyner common information, we show that they are equal for the Symmetric Binary Erasure Source. We then discuss the computation of $G(X; Y)$. In the second part, we will introduce a conjecture regarding the maximum mutual information a Boolean function can reveal about noisy inputs. Specifically, let $(X, Y)$ be a doubly symmetric binary source with cross-over probability $\alpha$. For any boolean function :\{0,1\}^n\to \{0,1\}$, we conjecture that $I(b(X^n); Y^n)\le 1-H(\alpha)$. While the conjecture remains open, we provide substantial evidence supporting its validity.

Keywords: Electrical Engineering.
Advisor: El Gamal Abbas A. primary advisor. Thesis advisor
Özgür Ayfer advisor. Thesis advisor
Weissman Tsachy advisor. Thesis advisor
"Injuring customs and corrupting hearts" [electronic resource] : pornography and modernity in China at the turn of the 20th century

This dissertation traces the emergence of "pornography, " a concept and commodity defined by competing claims to authoritative knowledge, in China circa 1880 to 1930. In this period, the rise of new information technologies and ideas about sexuality as fundamental to selfhood eroded extant structures of power and enabled alternative models of legitimacy. Sexually explicit representations and efforts to control them had a long but unstudied history in China; by connecting individuals' bodies and desires to massive institutional, ideological, and material transformations, this work offers a new perspective on a critical period in Chinese history. Existing scholarship furthermore links the "invention of pornography" to modernity as a uniquely Western phenomenon; this dissertation thus also offers an intervention on the uneasy conjunction of sexuality, information, and authority in the ongoing saga of global modernity.

Keywords: History.
Advisor: Sommer Matthew Harvey
Lee Haiyan advisor. Thesis advisor
Mullaney Thomas S. (Thomas Shawn) advisor. Thesis advisor
Wigen Kären
In-State Merit Aid and College Choice: New Jersey’s STARS Program as a Tuition Subsidy

In this paper, I test how the implementation of the NJ STARS program has changed patterns of college enrollment choice among eligible students. Applying difference-in-difference logic to a college choice model, I analyze the variation in college enrollment choices of students who were eligible for NJ STARS scholarship aid and students who were similarly qualified but not eligible. In addition, I measure several indicators of college quality and other characteristics of the school(s) in which the students enrolled for post-estimation analysis. My conditional logit choice model shows that students eligible for NJ STARS are 1.7% more likely to enroll in an in-state institution and 61% more likely to enroll in an instate, public, two-year college. Based on the enrollment shifts, I also find that eligible students, on average, enroll in an institution with a 0.79% lower graduation rate and 0.71% less in instructional spending, indicating adverse effects of the program.

Keywords:  Department of Economics
Stanford Department of Economics
College choice
college quality
in-kind subsidy
academic spending
merit aid
NJ STARS
Peltzman hypothesis
Thesis
Advisor: Hoxby Caroline
Insuring the uninsured [electronic resource] : analyzing aspects of federal health insurance programs

The first two chapters of this dissertation investigate the demand for publicly financed health insurance programs. Data from two separate surveys employing contingent valuation methodology were used to measure respondents' willingness-to-pay for an expansion of Medicaid, the provision of means-tested subsidies for the purchase of private health insurance, and the provision of subsidies for the purchase of private insurance by the chronically-ill. Using a parametric model, the average willingness-to-pay for the means-tested programs was found to be significantly less than the estimated costs of the programs. The aggregate willingness-to-pay for a program of public subsidies targeted for the chronically-ill may exceed the costs of such a program, depending on the specific characteristics of such a program. The distributional consequences of these publicly financed programs are also investigated. Estimates suggest that individuals in the lowest income quintile would receive net benefits from the means-tested programs, while individuals in the highest three quintiles would experience a loss in welfare. With respect to the program for the chronically-ill, the lowest three income quintiles would receive a net benefit, while individuals in the highest quintile would experience a net loss. Survey responses were found to be consistent with economic theory and of reasonable magnitude. Implications of these results for the Affordable Care Act (ACA) are discussed. The third chapter investigates how liberalizations in Medicaid eligibility affect the take-up rates by those whose eligibility is unaffected. A highly-stylized model of these impacts at the household level is developed. Empirical implications of the model are tested using federally mandated changes in Medicaid eligibility enacted in the late 1980s. A difference-in-difference model estimated at the individual level with data from the CPS supports the conclusion that the federal mandates resulted in significant increases in take-up rates amongst individuals who were eligible under previous eligibility criteria. Estimates using state-level data suggest that for each individual who enrolled in Medicaid under the expanded eligibility requirements, a further .83 individuals enrolled who were eligible under the previously existing eligibility requirements. The applicability of the stylized model to the ACA is discussed.

Keywords: Economics.
Advisor: Shoven John B. primary advisor. Thesis advisor
Kessler Daniel P.
Wright Gavin