VictorJuiz/thesis huggingface dataset:
Systematic effects in cosmic shear measurements for future ground-based optical surveys [electronic resource]

Cosmic shear measurements with large optical surveys have the largest potential power in the near future for revealing the nature of dark energy -- the greatest mystery in modern cosmology. This is one of the main science goals for the Large Synoptic Survey Telescope (LSST) project. The 10-year survey from LSST will image $\sim$ 20,000 square degrees of sky in six filter bands to a final survey depth of $-band magnitude $\sim27.5$ and median redshift $\sim1.2$. To take full advantage of this unprecedented statistical power, however, the systematic errors associated with cosmic shear measurements need to be controlled to a level similar to the statistical errors. In this thesis, I estimate the statistical and systematic errors in the cosmic shear dataset expected for LSST and investigate methods to mitigate some of the major systematic errors. The analyses are based on high-fidelity simulated images generated by a fast Monte Carlo ray-tracing code. The code models the interactions of the photons including major physical effects from the top of the atmosphere down to the charge-coupled devices, or CCDs. I first calculate the number density of % detectors? galaxies expected for a cosmic shear analysis with LSST, which provides a quantitative measure of the statistical power of the survey for these topics of investigation. Accounting for the realistic measurement errors for shear and blending/masking effects, I show that $\sim26$ arcmin$^{-2}$ well-measured galaxies is expected using conventional algorithms, but the number can increase by as much as

Keywords: Physics.
Advisor: Kahn Steven M. (Steven Michael)
Schindler Rafe
Blandford Roger D.
Kuo Chao-Lin (Physics professor) advisor. Thesis advisor
Systems for real-time image-guided therapy [electronic resource]

Image-guided therapy is a recently developed field that combines the use of computer technology with tracked surgical tools and pre-operative or intra-operative images for planning, guiding, and performing diagnoses and surgical interventions in a minimally invasive manner. It has been used in neurosurgery, orthopaedics, otolaryngology, and plastic and cranio-facial surgeries to improve patient safety and health-care outcomes. This technology relies upon a set of complex subsystems to perform tasks such as optical and electromagnetic 3D tracking, ultrasound imaging, endoscopy, and overall navigation, yet they have not been well characterised in this regard. This work presents methods and results for calibration and error analysis of these subsystems, and presents solutions to issues that impede their use for practical and intuitive real-time navigation and guidance in the operating room. Keywords: 3D, accuracy, calibration, computer graphics, distortion correction, electromagnetic tracking system, error analysis, freehand, graphics processing unit, image-enhanced endoscopy, image-guided surgery, jitter, lens distortion, minimally invasive surgery, optical tracking system, real-time, texture mapping, ultrasound, virtual endoscopy, visualization, volume rendering.

Keywords: Electrical Engineering.
Advisor: Nishimura Dwight George primary advisor. Thesis advisor
Shahidi Ramin primary advisor. Thesis advisor
Jeffrey R. Brooke advisor. Thesis advisor
Taking the "history" out of historical thinking to teach adolescents to evaluate informational text [electronic resource]

Twenty-four eighth-grade students in an urban public school participated in a classroom-based design experiment for four months. The purpose of the study was to discover how an established high school history curriculum featuring multiple documents and historical thinking strategies can be modified for use with younger students of average reading ability and applied to nonhistorical topics in a classroom setting. Classroom studies about historical thinking, whether large-scale interventions (De La Paz, 2005; Nokes, Dole, & Hacker, 2007; Reisman, 2012) or exploratory stories (Stahl, Hynd, Britton, McNish, & Bosquet, 1996; Wolfe & Goldman, 2005; VanSledright, 2002; Wineburg, 1991a) have focused understandably on the discipline of history. Most research about multiple documents reading has been primarily postsecondary psychological studies that explored what students already know how to do (Bråten, Strømsø, & Britt, 2009; Strømsø, Bråten, & Samuelstuen, 2003). Training studies for school age students evaluating multiple documents have been of short duration and have sought primarily cognitive explanations (Macedo-Rouet, Braasch, Britt, & Rouet, 2013). The present study attempted to discover how to teach these skills in an authentic, long-term classroom setting; how historical thinking strategies can be applied to nonhistorical text; how young adolescents develop such skills over time and in a social setting; and how teachers can apply these principles without relying solely on professionally developed curricula. In accordance with the principles of a design experiment, curriculum and instructional methods were modified regularly throughout the intervention. Findings included insights into how written responses to historical thinking questions do not adequately reflect the complexity of thinking students are able to communicate in small-group discussions; the importance of social interactions in developing these critical reading skills; and a framework of instructional design for teachers who wish to use historical thinking strategies to promote critical reading of contemporary informational texts. In particular, one of the more successful modifications was the reconfiguration of the sourcing task from its traditional presentation in a historical thinking curriculum as a reading task featuring six constant factors to consider. An informal assessment of historical thinking conducted prior to and after the intervention showed a significant increase in students' ability to think historically.

Keywords: Education.
Advisor: Wineburg Samuel S. primary advisor. Thesis advisor
Aukerman Maren (Maren Songmy)
Juel Connie advisor. Thesis advisor
Shulman Lee S. advisor. Thesis advisor
The Ambiguity of Nuclear Commitments

Since the 1950’s, the United States has engaged in nuclear sharing with its NATO allies. However, the Nuclear Nonproliferation Treaty (NPT) prohibits the transfer of nuclear weapons to non-nuclear weapon states. Thus, there has been a debate over the effect of nuclear sharing on the NPT. This thesis finds that nuclear sharing originally strengthened the NPT by discouraging proliferation by West Germany. However, U.S. efforts to preserve NATO’s pre-existing arrangements produced ambiguity in Articles I and II. This ambiguity has since limited the scope of debates over the legality of nuclear sharing at NPT Review Conferences. However, the potential release of U.S. tactical nuclear weapons to NATO allies constitutes the main source of contention between NATO and the NAM in these debates. Security reasons for keeping the weapons are tenuous: their presence is not necessary to discourage Turkey from developing nuclear weapons if Iran acquires them and their role in reassuring Eastern European NATO allies and deterring Russia is limited. Moreover, there are major flaws in relying on the weapons for reassurance and extended deterrence against Russian threats to cyber security, energy security, and political stability. The implication of this thesis is that NATO’s nuclear sharing arrangements undermine the NPT by setting a precedent for other countries to engage in similar practices and hindering Turkey’s goal of building a Nuclear Weapons Free Zone in the Middle East. Projecting forward, the U.S. could explore alternative avenues for reassuring its NATO allies and negotiate reciprocal reductions in tactical nuclear weapons with Russia.

Keywords: CISAC
Center for International Security and Cooperation
Stanford University
nonproliferation
North Atlantic Treaty Organization
nuclear sharing
Firestone Medal Award
Thesis
Advisor: Sagan Scott D.
The British Aren’t Coming: Why the French Intervene in their Former African Colonies and the British Do Not

Despite close parallels throughout their imperial histories, Britain and France have diverged greatly in how often they have intervened in former African colonies since independence. In this thesis, I explore how the nature and frequency of military interventions is directly rooted in the histories of the empires themselves, including imperial governance, decolonization, and post-colonial regimes. Through case studies of some of the most recent and prominent interventions for each country (Sierra Leone in 2000 for Great Britain; Côte d’Ivoire in 2002 and 2011 for France), as well as instances of non-interventions, I show how colonial legacies play a direct role in determining intervention. Although neo-colonial links and legacies have a significant and expected impact for France through its network of “Françafrique,” their influence on the British is subtler. History shows us that Britain did not value its African empire as much as France did, and consequently it intervened there less. Nonetheless, Prime Minister Tony Blair’s Doctrine of the International Community, under which the Sierra Leone and other interventions took place, had subtle neo- imperial undertones, suggesting a different kind of colonial legacy. This legacy has been indirectly continued across party lines by the government of Prime Minister David Cameron. Additionally, I find that interventions to protect certain postcolonial interests, such as significant expatriate populations, might elicit a swift, but limited, response that then evolves into a more robust mission. Other legacies, like regional military presence, facilitate interventions once decided or preclude their possibility. Finally, I conclude that assumptions that the international community can rely on former colonial powers to shoulder the military burden in Africa is inaccurate, having never been the case for Britain and decreasingly so for France, as it shifts to a less neo-imperial attitude toward Francophone Africa.

Keywords: Center for International Security and Cooperation
British history
French history
British foreign policy
French foreign policy
Africa
post-colonial
military intervention
Thesis
Advisor: Naimark Norman
Holloway David
The Case for Free Trade Agreements: Historical Perspectives and a Projection for China, Japan, and Korea

In recent years, several major Free Trade Agreements (FTAs) have been proposed amongst countries that encompass a lion’s share of the world’s economic output.Thus, understanding the impact of FTAs on trade and income has become more crucial than ever. This paper sheds light on both the past and future effects of FTAs via a two-step approach. First, I use a gravity model to measure the effect of existing FTAs on the bilateral trade flows of member countries. Second, I project the potential increase in trade and GDP from a China-Japan-Korea (CJK) FTA specifically, through a combination of gravity model analysis and calculations based on various economic growth and tariff reduction scenarios. The results show that historically, FTAs have greatly increased trade amongst member countries. Looking forward, I estimate that a CJK FTA increases intraregional merchandise trade by 21%-46% and services trade by 49%-79%, with commensurately large increases in GDP. This suggests that FTAs might play a major role in boosting world economic growth.

Keywords:  Department of Economics
Stanford Department of Economics
FTA
gravity model
trade liberalization
tariff
non-tariff barrier
Thesis
Advisor: Boskin Michael J.
The Effects of the Thai College Admissions System on Private Tutoring Expenditure, Income and Achievement Disparities

College admissions in Thailand is under a centralized systems in which acceptance is based on a scoring system that combines students’ performance on the college entrance exam and their high school GPA. The system has a reputation for objectivity and fairness, as every student has equal chance of taking the same test. In this paper, I explore whether the centralized system can result in a wider achievement gap in students of different socio-economic status. I firstly assess whether the system leads to a higher demand in private tutoring among high school students by observing how household expenditure on private tutoring has changed after a change in the scoring system by giving more weight to test score was enforced; secondly, I explore the relationship between tutoring expenditure and education outcome. I find statistically significant effects on private tutoring in response to the policy change, with different magnitude and direction for different socioeconomic status of the households. I also find a strong correlation between households’ investment in private tutoring and college attendance. These results suggest government policy changes in education to increase attendance. These results suggest government policy changes in education to increase equality of opportunity, including investing more in the schools with less emphasis on the test scores for college admissions.

Keywords:  Department of Economics
Stanford Department of Economics
College admissions
Private tutoring
Thailand
Income and achievement gap
Thesis
Advisor: Bettinger Eric
The Efficiency of Wikipedia’s Evolution

Wikipedia, the world’s most popular encyclopedia, is a unique enterprise characterized by its purely decentralized production. Thus, it is important to understand whether editors produce the pages in an ecient manner. I examine how eciently Wikipedia has developed from three perspectives. First, I evaluate whether the editors produce the pages with the highest eventual views first. I find that at a given point in time, editors create roughly 80% of the maximum possible views that could have been created up through that time. Second, I examine whether pages are created in order of how well-connected they are to other pages in the link structure, so how easy they are to find. I find that a page’s probability of being created at any point in time is significantly and substantially increasing in its relative number of views and connections. However, this e↵ect diminishes with time and page creation was much less sensitive to these measures in 2008 than in 2001. Third, I compare which pages frequent versus infrequent editors create. I find that frequent editors tend to produce highly-viewed pages while infrequent editors tend to produce better connected pages.

Keywords:  Department of Economics
Stanford Department of Economics
Wikipedia
Eciency
Knowledge Production
Decentralized Platforms
Internet
Public Goo
Thesis
Advisor: Levin Jonathan
The Structural and Bonding Behavior of 3d Transitional Metal Carbonates at Mantle Pressures

Carbonate minerals are potentially major hosts for carbon in the lower mantle of the Earth. Since the mantle holds 100 times more carbon than the crust, atmosphere, and ocean reservoirs, a thorough understanding of the deep carbon cycle is necessary to model the global carbon cycle. High pressure studies are important because they help us define the stability of crystal phases that exist at extreme conditions and how these new carbonate structures hold carbon in the deep carbon cycle. Fe2+, the 3d transition metal in siderite (FeCO3), undergoes a coupled electronic spin transition and an isostructural phase transition at approximately 46 GPa, as well as a later structural phase transition at ~100 GPa. In contrast, Mn2+ in rhodochrosite (MnCO3) undergoes a structural phase transition to an orthorhombic structure at approximately 50 GPa and an electronic spin transition at ~100 GPa. These transitions were observed using in-situ Raman spectroscopy and X-ray diffraction coupled with high-pressure diamond anvil cells. Studies of electronic spin and structural phase transitions in carbonates are crucial for developing the phase diagrams and understanding the properties under the extreme conditions in the deep Earth that govern the stability and behavior of carbonates as possible hosts for carbon in the lower mantle.

Keywords:  Department of Geological and Environmental Sciences
School of Earth Energy &amp; Environmental Sciences
deep carbon
Thesis
Advisor: Mao Wendy
Brown Gordon
Thermal modeling of coring and drilling operations for solar system exploration applications [electronic resource]

Heat created at a drilling site by the motion of a rotary-percussive coring system is a highly problematic, yet unavoidable consequence of geologic sample acquisition. This heat is particularly hazardous in the dry drilling techniques to be used for Mars sample return (MSR) and missions to the Solar System's moons, since heat has the capability of altering material composition or evolving compounds of interest, including water. In addition, sublimation of any ice contained in the rock or soil formation could cause vapor deposition onto cooler areas of the bit, permanently freezing the bit in the borehole and potentially leading to mission failure. A thermal model capable of predicting temperature profiles throughout the geologic formation and bit is an essential tool in creating drilling schedules that minimize both damage to samples and risk to system hardware. This investigation uses a series of drilling and coring tests, performed with a prototype MSR sampling system, to gather thermal data on a suite of solar system analog materials across a variety of atmospheric and starting thermal conditions. The materials and conditions were chosen to emulate rock types and conditions found on Mars and potentially on Jupiter's Moon Europa. The data is used to verify the accuracy of a finite element model specifically designed for this application. The model may be used to prevent rock or cuttings temperatures from reaching threshold values by predicting necessary pauses and/or power reductions. The average error of the model in predicting temperature profiles is 6.83%, with the errors of only two of eighteen tests exceeding 10%. A number of important relationships are found using the thermal profiles provided by the model. A linear relation between unconfined compressive strength (UCS) and maximum core temperature is developed, with decreased rock starting temperature leading to an increase in rock core temperature change. Maximum core temperature is dependent on system specific energy, defined as the ratio of energy consumption to rock volume excavated by the bit; rock parameters; operational parameters; and bit geometry by a simple power law. Energy transmission efficiency into the rock by a percussive bit is found to increase linearly with UCS and is also dependent on rock ambient pressure due to the subsequent changes in friction. Cuttings temperatures are identified by the model, which aids in the construction of sample acquisition schedules.

Keywords: Aeronautics and Astronautics.
Advisor: Cantwell Brian primary advisor. Thesis advisor
Christensen R. M. (Richard M.) primary advisor. Thesis advisor
Hubbard Scott
Pollard David D. advisor. Thesis advisor
Zacny Kris
To be (moral) or not to be [electronic resource] : an analysis of the interaction between categorical identity and moral identity

Organizations have social identities that encompass both a categorical identity, based on products sold or services provided, and a more individualized, organization-specific identity not necessarily based on products, which often consists of moral features such as corporate social responsibility (CSR) activities or actively engaging in the social well-being of local communities. Recent sociological research on organizational categories has shown that audiences prefer organizations that conform to a single, clear category. At the same time, social psychological research on morality shows that individuals reward moral actors and punish immoral actors. This dissertation examines how conformity to a categorical code differently affects audiences' reactions to organizational actors' moral and immoral actions. In Section I, I use two empirical settings to examine how the clarity of an organization's categorical identity affects the way audiences react to the organization's moral identity based on CSR in a local community. First, using a series of experiments, I show that organizations in a single category gain appeal when they perform a CSR activity while organizations that span multiple categories garner less appeal for making the same moral identity claim. I also replicate and extend these findings in an empirical analysis using corporate financial performance data, which shows that penalties also extend to organizations in ambiguous product categories, in addition to those operating in multiple categories. An important implication of these results is that organizations with unclear categorical identities can have greater difficulty cultivating moral identities that would serve to differentiate them in the marketplace. In Section II, I examine how category clarity affects audiences' response to immoral actions on the part of organizations. Using a series of experiments, I show that organizations with unclear categorical identities are punished more when suspected of immoral behavior than organizations operating in a single product category. However, when the immoral behavior is beyond suspicion and is accepted as fact, the buffering effect of a clear categorical identity disappears. In line with results from the studies in Section I, these findings suggest that organizations with unclear categorical identities can have a more difficult time rebounding from perceived immorality in the marketplace. Overall, the results from this dissertation enrich the current literature on organizational identity and expand on ideas about how the cognitive process in which rewards and penalties are meted out is affected by the categorical clarity of an organization.

Keywords: Business.
Advisor: Sorensen Jesper B.
Hannan Michael T. advisor. Thesis advisor
Soule Sarah Anne
To the gentle reader [electronic resource] : prefaces and books in early modern England

This project examines the preface, especially the dedication and epistle to readers, in Renaissance books. Its primary claim is that the preface, despite being a marginal element of the book, played a central role in the development of literary and print culture in early modern England. It demonstrates how prefaces shaped the practices of reading, publishing, and authoring books during a period when the nature and conventions of those activities were still unsettled. Moreover, this project brings the preface's significance to bear on issues such as Renaissance humanism, periodization and early modernity, early modern authorship, and dramatic publication.

Keywords: English.
Advisor: Orgel Stephen primary advisor. Thesis advisor
Greene Roland
Summit Jennifer advisor. Thesis advisor