VictorJuiz/thesis huggingface dataset:
A skinned tetrahedral mesh for hair-water interaction

This dissertation presents kinematically deforming skinned mesh (KDSM), a novel data structure that serves as a foundation to implement hair-water simulation system for hair animation, robust volume-conserving water simulation, and hair-water interaction. Both hair and water simulation techniques have become very popular in the entertainment industry, especially in motion pictures; however, these techniques suffer from limited scalability, difficult artist control, and a lack of a flexible framework. We present a skinned tetrahedral mesh based framework that efficiently computes hair, water, and hair-water phenomena while offering a powerful control for artists and providing a flexible framework to integrate multiple methods. After the introductory chapter, we discuss our novel hair animation technique and hair-water interaction scheme. We provide the following layering framework which is well suited for an iterative feedback loop of a creative process, offering a straightforward and powerful artist control by separating bulk hair motion and intricate hair motion. For an input character animation, we initialize a tetrahedral mesh, KDSM, in a sculpt/normalized/T-pose and generate a corresponding animation sequence of KDSMs. We apply kinematic skinning by embedding hair particles to follow the KDSMs to achieve bulk hair motion, and additionally apply dynamic skinning by applying more deformation on the copied KDSMs for external forces. Then, if intricate hair motion is required, we use either blendshape hair for precomputed intricate hair motion within the KDSM or individual hair simulation for dynamic motion. This chapter ends with a discussion of how we run our novel hair-water solver with a hair porosity scheme to handle hair-water interactions in the Eulerian grid. In the next chapter, we present a robust volume-conserving character-water interaction. A coarse Cartesian Eulerian grid is used to capture bulk water motion, and our novel volume-conserving volume-of-fluid method in arbitrary Lagrangian-Eulerian mesh derived from the KDSM is used to achieve intricate water motion with high adaptivity. We precompute various auxiliary information to improve the simulation time and the robustness. Also discussed is a fast, robust, and simple partitioned approach to two-way couple our two distinct fluid solvers. We present a novel volume-of-fluid solver which can control fluid motion more easily, such as adhesion effects and anisotropic porosity for hair. Our novel water surface reconstruction produces a smooth and temporally coherent surface. Finally, we demonstrate hair-water interaction in a setting similar to that discussed in the previous chapter with improved visual quality.

Advisor: Fedkiw Ronald P.
Fatahalian Kayvon 
Levis Philip
Slow and fast dynamic processes in hybrid perovskite solar cell materials

Hybrid organic-inorganic perovskites have rapidly become an important class of semiconductors for solar cells and other optoelectronic devices, such as photodetectors, LEDs, and lasers. Perovskite solar cell efficiencies have skyrocketed in the past few years and are now approaching those of mature technologies such as silicon and cadmium telluride. Because perovskites can be solution processed from inexpensive materials, they hold great promise for low-cost solar cells as well as for lightweight and flexible devices. Unlike conventional inorganic semiconductors, hybrid perovskites are a fundamentally dynamic material system. In perovskites, chemical and physical processes that occur across a vast range of timescales have influence on the processing, properties, and degradation of perovskite films. This dissertation presents two dynamic processes that occur on very different timescales and describes their impacts on the formation and performance of the perovskite methylammonium lead iodide (CH3NH3PbI3), which is a model compound for this class of materials. The first part of this dissertation describes a slow process that leads to the formation of high-quality perovskites. A popular method for depositing perovskite films employs chlorine in the starting materials even though almost no chlorine remains in the final film. I show that this deposition proceeds via a crystalline intermediate phase that is an altogether novel material and that the transformation from intermediate to perovskite requires the evaporation of chlorine through a self-regulating mechanism. While most perovskites form in seconds or minutes, this evaporation process occurs on the timescale of hours and the ability to retard the formation of the perovskite results in high quality films that exhibit impressive optoelectronic performance. The second half of this dissertation focuses on a fast process that occurs in the perovskite crystal lattice. In solid materials, atoms collectively vibrate in well-defined ways, and these vibrations are called phonons. One reason that phonons are important is that they interact with electrons and thus can have substantial impacts on the operation of solar cells or other devices. I demonstrate that acoustic phonons, the type that are generally responsible for transmitting heat, have extraordinarily short lifetimes in the perovskite methylammonium lead iodide. These short lifetimes have direct implications on the cooling and transport of electrons and reflect a key difference between hybrid perovskites and conventional inorganic semiconductors.

Keywords: Chemistry.
Advisor: Karunadasa Hemamala
Toney Michael Folsom
Salleo Alberto
Small molecule and protein modulators of microtubule function

The microtubule cytoskeleton is one of the principal components of eukaryotic cells. Microtubules are involved in the processes of cell division, transport, signaling and differentiation. Furthermore, the microtubule protofilaments can be arranged into a nine-fold symmetric, triplet microtubule structure - the centriole. The centriole has two main roles: to mediate cell division by organizing the spindle, and to mediate signaling by acting as a base for a cilium. In both contexts, microtubules are made up of alpha- and beta- tubulin dimers. The beta-tubulin subunit in the dimer has GTPase activity integral to the properties of microtubules. When the terminal tubulin dimer is in the GDP form, the microtubule is less stable and is usually depolymerized. This process of polymerization and rapid depolymerization of the microtubule is named dynamic instability and is a key property of the microtubule cytoskeleton. This work describes small molecule and protein modulators of microtubule stability and function. Since microtubules play a key role in organizing the mitotic spindle, it has been a key target for cancer therapies. One such molecule, paclitaxel, is a potent microtubule stabilizer that can result in mitotic failure. In this work, a chemical biology approach is used to describe an in silico discovery of new small molecules that bind to the paclitaxel-binding site. The predictions were validated and revealed that commonly used selective estrogen receptor modulators are able to bind microtubules and lead to their stabilization. Centrioles are functionalized by the binding of a variety of protein structures. The exact nature of how these protein structures attach to the microtubules of the centriole have not been characterized. In this work, an evolutionary approach is used to describe potential structural proteins of centriolar accessories. Using cell biological approaches, we investigate the attachment and regulation of a particular centriole accessory, the distal appendages. Overall, this work uses a combination of approaches in answering questions regarding the microtubules cytoskeleton on different scales. Drawing on knowledge from the protein crystal structure of tubulin, new microtubule-binding small molecules were predicted and tested. Furthermore, we investigate the complex microtubule structure, the centriole, and the attachment of its known accessories using both evolutionary and cell biology approaches.

Keywords: Biology.
Advisor: Stearns Tim 
Feldman Jessica L.
Kopito Ron Rieger
Straight Aaron
Social Media Advertisements and Millennials: An Analysis of the Influences on Consuming Behavior

This paper investigates how advertisements through social media platforms affect the purchasing behaviors of millennial consumers. As social media become even more integrated into daily life, it is becoming harder to avoid the subtle influences stemming from our screens. In addition, because the millennial demographic spends more time online than any other age group, they are a prime focus group for companies to target. This paper aims to consolidate and analyze current literature in psychology, marketing, and sociology regarding Millennials’ spending habits and preferences. Furthermore, it explores how their relationship with smartphones affects how brands can influence them online. By being aware of these relationships and factors, Millennials can have stronger autonomy in their buying behavior and prevent companies from subtly controlling their individual preferences.

Keywords:  Department of Communication
Millennials
consumer behavior
advertisements
social media
smartphones
influence
uses &amp; gratification theory
social cognition
social comparison theory
mere exposure effect
status
group norms
Stanford University Department of Communication
Thesis
Advisor: Hamilton James
Social Presence in Virtual Reality: Definitions, Theories, Studies, and Uses

This paper aims to provide the reader with a better understanding of the concept of social presence and how it is studied and applied in virtual reality. The first section is dedicated to exploring the definitions and theories of social presence that have been used throughout the years. The second section is dedicated to summarizing the findings from different research
studies involving social presence and virtual humans. The last two sections cover real world examples of how social presence functions in virtual reality as well as possible future uses. The paper then concludes with remarks about the performance of virtual reality in relation to social presence and future steps to be taken.

Keywords:  Department of Communication
social presence
co-presence
virtual reality
virtual humans
avatars
embodied agents
Thesis
Advisor: Bailenson Jeremy
Sociodemographic Predictors of Patient Migration and Waitlist Outcome for Liver Transplantation in the United States

Background: Faced with ongoing organ shortage and regional differences in organ availability, patients requiring liver transplantation may relocate to improve their chance of transplantation.
Objective: To identify predictors of patient migration for liver transplantation in the United States (US), and to evaluate the effect of migration on waitlist outcome.
Design: This is a retrospective cohort study of adult liver transplant candidates and recipients from 2004 to 2016.
Setting: The Organ Procurement and Transplantation Network database represents all transplant and waitlist events in the US.
Patients: Eligible patients included adults living in a zip code with available median income data. Patients listed or transplanted for multi-organ transplantation other than liver-kidney, as Status 1 priority, or with insurance through the Veterans Affairs system, were excluded.
Measurements: Migration was defined as travel to a transplant center greater than 500 miles from a patient’s zip code and outside their home transplant region. We identified sociodemographic factors associated with migration and assessed the impact of migration on waitlist outcomes.
Results: Of 61,007 eligible recipients, 2,066 (3.4%) migrated for transplantation. Migration was associated with non-black race, non-Medicaid payer, residence in a higher income area, and education beyond high school. Of 104,914 primary waitlist registrations during the same period, 2,930 (2.8%) were listed at a distant center. In multivariable competing risk analysis, with liver transplantation as a competing event, distant listing was associated with reduced 1-year waitlist mortality (subdistribution hazard ratio 0.80, 95% CI 0.71-0.90).
Conclusion: Listing at a distant center, which often involves considerable travel and resources, is associated with reduced waitlist mortality. Geographic disparity in access to liver transplantation disproportionately affects minority patients with lower income and public insurance.

Keywords:  Department of Health Research & Policy
Mannalithara, Ajitha
Liver transplantation
geographic disparity
organ allocation
Thesis
Advisor: Kim W. Ray
Friedman Gary
Solidarity in action : a case study of journalistic humanizing techniques in the San Francisco homeless project

Solidarity is a political commitment to social justice that translates into action, and is a longstanding, though unacknowledged, ideal within American journalism that humanizes marginalized communities. To explain the role and significance of solidarity in journalism that humanizes marginalized communities, this dissertation explicates the concept of solidarity, applies solidarity to journalism, and develops an empirical case study of a 2016 journalistic collaboration called the San Francisco Homeless Project to demonstrate how journalistic humanizing techniques invite and impede solidarity. Based on semistructured interviews with participating journalists paired with textual analysis of their stories, this dissertation finds that journalists humanize homeless people through personalization techniques that appeal to empathy by representing homeless people's personal problems, and do so at the expense of solidarity. Empathy becomes a barrier to solidarity in journalism because it individualizes social injustice. On the other hand, journalists also rely on politicization techniques that invite solidarity by representing homeless people as living within unjust conditions produced by systemic factors that they cannot individually surmount. This dissertation concludes by arguing that solidarity provides a news value for guiding journalistic practice in the direction of social justice.

Keywords: Communication.
Advisor: Glasser Theodore L. 
Hamilton James
Jiménez Tomás R. (Tomás Roberto)
Turner Fred
Solid-state architecture for an elevated-temperature photoelectrochemical cell

Solar fuels can be utilized to overcome the storage and distribution limitations of solar energy by using sunlight to convert water into hydrogen fuel. Photoelectrochemical cells (PECs) have been investigated as a tool for solar-to-hydrogen conversion for several decades, and the majority of PECs used for solar water splitting operate near room temperature with a liquid or polymeric electrolyte. These devices are typically limited by slow kinetics and thermodynamic losses at interfaces, and have often suffered from severe stability concerns. My colleagues and I have recently shown that even a small temperature increase can substantially improve the minority carrier collection efficiency of PECs, thus increasing the photocurrent density output by the cell. Additionally, using a detailed-balance approach, we have shown that a solid-state composite device operating at 450 C could achieve solar-to-hydrogen efficiencies as high as 17%. In this dissertation, I first review our experimental work confirming enhanced water-splitting performance for modest increases in temperature up to 70 C. These enhancements are observed for multiple metal-oxide systems, including iron oxide and bismuth vanadate. I then describe how we developed a composite, solid-state architecture for elevated temperature photoelectrochemistry using an oxide-based solid electrolyte. Since the oxygen evolution reaction is typically limiting due to its catalytic complexity, most of the subsequent work focuses on this reaction at the photoanode surface. Next, I discuss the fabrication and characterization of a solid-state PEC composed of a bismuth vanadate light absorber and a yttria-stabilized zirconia thin-film solid electrolyte. Our cell design has enabled us to achieve photocurrent densities above 100 mA/cm^2 at temperatures between 300 to 400 C -- among the highest current densities observed in literature for a solid-state photoelectrochemical cell. Throughout, I highlight my work on optimizing the oxide layers, current collector morphology, and deposition techniques to improve cell performance. To better understand the results, I share our findings regarding the role of thermal effects on the observed performance, and I demonstrate my initial results for future materials of interest like titanium oxide. Ultimately, my thesis conveys the benefits of elevated temperature on PEC performance, the role of heterojunctions on enhanced charge-separation, and the opportunity provided by thin-film solid electrolytes to enable high photocurrent densities for photon-assisted oxygen evolution.

Keywords: Materials Science and Engineering.
Advisor: Chueh William
Melosh Nicholas A. 
Prinz F. B.
Solvolysis of enantioenriched dihalides and its application to the synthesis of the brominated chamigrene sesquiterpenes

To date, more than 2,000 natural products have been isolated and structurally characterized which contain either a chlorine- or bromine-bearing stereocenter. Of these secondary metabolites, approximately 500 contain a brominated five-, six-, or seven-membered cyclic scaffold that is often further embedded within a larger terpene-derived polycyclic architecture. Despite the abundance of these motifs in nature, synthetic technologies providing enantioselective access to these structures are largely deficient. To access such structural motifs, we developed a methodology wherein enantioenriched bromochlorides were subjected to ionizing media (hexafluoroisopropanol) to generate a non-racemizing bromonium ion, which could be captured intramolecularly leading to a cyclized product with near-perfect enantiospecificity. This solvolytic bromonium-initiated cyclization was used to access numerous natural product-relevant scaffolds. The analogous enantioenriched dibromides were found to rapidly racemize under these ionizing conditions. This methodology was applied to the synthesis of several brominated chamigrene sesquiterpenes, a class of approximately 100 red algal-derived secondary metabolites. The flagship member of this class, (+)-aplydactone, and its putative biosynthetic precursor, (--)-dactylone, were synthesized enantioselectively for the first time.

Keywords: Chemistry.
Advisor: Burns Noah
Du Bois Justin 
Waymouth Robert M.
Songs of empire : embedded hymns and the Latin hymnic tradition

Our understanding of the Latin hymnic tradition has long been impeded by a number of challenges ranging from basic evidential scarcity to formal analytical bias. In this dissertation, I argue for a common set of themes and contexts that unites the Latin hymnic genre. Though our earliest Latin hymns (the carmina of the Salii and Fratres Arvales) are only fragmentary, I show in the first portion of the dissertation that we can nevertheless identify in them themes of war, agriculture, and liminality, the former two in particular idealized cornerstones of early Roman society. As a result, later Latin authors had a vested interest in portraying the Latin hymnic tradition as an indigenous Roman genre, despite its obvious Greek influences. In the latter half of my work, I take case studies of embedded hymns from early imperial authors and show how in both the Augustan and Flavian periods, hymns staged concerns around political continuity with this idealized Roman past. Through its diachronic study of Latin hymns from roughly the 3rd century BCE to its Common Era counterpart, this dissertation ultimately argues that the thematic unity and formal flexibility inherent to the Latin hymn allowed Roman authors to turn work in any poetic genre into a song of empire—in the late Republic and early Empire, poets used embedded hymns to accommodate the changing Roman political landscape, styling their hymnic praise as carmina 'condita' and the refined refoundation of Rome's mythic past.

Keywords: Classics.
Advisor: Barchiesi Alessandro 
Krebs Christopher B. 
Harrison S. J. 
Stephens Susan A.
Sovereign investors as agents of institutional change

Every year there is a gap of USD1 trillion between investments made into infrastructure and the amount needed to achieve global access to water, energy, transportation and waste treatment, while mitigating global CO2 emissions. Debt-ridden, governments alone can't fill this gap. Private investors have increased their investments, but often shy away from projects that could have the most impact on development. However, new types of organizations, sovereign investors, could help governments plan and finance infrastructure for long-term development, while carving out attractive financial opportunities for private investors. Sovereign investors are government-owned investment management companies who are increasingly investing both for national development and financial returns. Chapter 2 of this thesis brings the first large-scale qualitative study of sovereign investors' identities and investment strategies, using computer-assisted text analysis on 57 sovereign investors' annual reports. It shows that most sovereign investors boast development as their mission and invest in the real economy. Investing solely for financial returns on financial markets is losing steam among these investors and characterizes primarily investors from OECD countries. Theoretically, this chapter gives an example of "path generation" as an alternative to "globalization" and "path dependency", in which signs of compliance with different institutional orders are combined. Chapter 3 gives a detailed example of how a sovereign investor attracted USD50 bn over 10 years and transformed an agricultural region into an urban area with six vibrant industrial clusters. By combining a network analysis of the co-investments in the region with interviews of the main types of actors, it shows how a sovereign investor crafted its network to allow for both innovation and stability, two ingredients necessary for economic development. Theoretically, the chapter matches a set of network centrality measures with strategies for actors to manage divergent expectations from multiple actors. Chapter 4 builds on the idea that organizations at arm's length from governments can bring the innovation necessary to face "grand challenges" such as the infrastructure gap. Through a comparative case study of four independent infrastructure agencies in Australia, it shows how units that builds legitimacy towards several government actors can convince government actors to adopt innovations, and keep the cognitive distance that enables them to innovate. However, maintaining legitimacy towards several actors is hard to sustain over the long run, which explains why many units become cognitively close to other government actors and revert to incremental instead of radical innovation over time

Advisor: Levitt Raymond E. 
Barnett William P. 
Monk Ashby H. B. (Ashby Henry Benning)