VictorJuiz/thesis huggingface dataset:
Symbolic protocol composition logic [electronic resource] : proving network protocols to be secure

While computational methods for the verification of network protocols view cryptographic operations as the manipulation of bitstrings, symbolic approaches view the application of cryptography as manipulation of symbols according to a term grammar, equations, and term manipulation rules. Computational cryptography is very hard given the immense complexity of network protocols. Symbolic cryptography takes security of cryptographic primitives as a given and thereby enables a researcher to focus on protocol-level notions of security, such as authentication of protocol participants and secrecy of nonces and keys. Protocol Composition Logic (PCL) can be characterized in the following ways: it is a direct logic; it is a logic producing before-after assertions; symbolic and computational versions of PCL are maintained and proven sound independently; it is compatible with different logics for reasoning between the preconditions and postconditions. My work extends symbolic PCL. On the theory-building side, I first invent an expressive imperative protocol description language with execution rules and then on top provide a logic for stating security properties of protocols described in my protocol description language. The protocol description language comes with a message algebra with a syntax, a detailed type system, equations, 2 different normal forms, and 3 different types of term containment. My logic consists of a language for formulating assertions about protocols and a semantics for that language. Among other things, I have refined PCL's notion of honesty, clarified the dependence of assertions on setup assumptions, and made explicit the dependence of secrecy proofs on role parameters. I provide an updated proof system (axioms and rules) for my updated logic. On the problem solving side, I extend the existing treatment of secrecy, culminating in a proof of secrecy for the IEEE 802.11-2012 4-Way Handshake. My approach lets us prove secrecy also for keys and tags (macs, signatures, and hashes), not only nonces. Previous treatment relied on honest protocol participants not revealing the protecting keys, and this assumption has now been made explicit. Proving secrecy no longer relies on induction over the artificial notion of a 'basic sequence'. On the development side, my thesis provides novel, clear notation (usable in all of symbolic cryptography) and a rigorous exposition (suitable for direct proof automation).

Advisor: Mitchell John C. primary advisor. Thesis advisor
Dill David L. advisor. Thesis advisor
Pratt Vaughan R. advisor. Thesis advisor
Synthetic strategies for shape control and tunable doping of colloidal zinc oxide nanocrystals [electronic resource]

Zinc oxide (ZnO) is a wide-band gap II-VI semiconductor with various optoelectronic applications owing to its transparency to visible light and tunable optical/electronic properties achieved by doping. In this dissertation, a modular synthetic design approach is presented that overcomes many of the synthetic challenges associated with zinc oxide nanorods and enables nearly independent control of morphology and impurity incorporation. Manipulation of alcoholysis reaction kinetics through multiple precursor solution injections and judicious use of phosphonic acid surfactants enables the synthesis of nanorods with highly tunable shapes, lengths (40-200 nm), diameters (6-80nm), and doping levels (with aluminum and indium cations).Subsequently, this dissertation focuses on strategies to simultaneously control the shape and doping level of zinc oxide nanorods. The increased stability of dopant precursors, limited solid-state diffusion in ZnO nanocrystals, and unintentional dopant-induced shape effects make it extremely difficult to control both shape and doping in anisotropic zinc oxide nanorods. Here, we show that growth of an undoped ZnO shell incorporates surface segregated dopants on ZnO nanorods with high (> 50%) efficiency and preserves nearly the entire nanorod morphology. Both nanorod shape and dopant incorporation are achieved through kinetic control of reaction conditions. The structural and optoelectronic effects of dopant incorporation in these nanorods are characterized and discussed with an emphasis on near-infrared plasmonic applications. Finally, solution processing of ZnO nanocrystals into nanostructured films via spray deposition is explored as a low-cost, scalable method for improved optical performance in photovoltaic devices. Spray deposited nanostructured ZnO films fabricated form precursor nanoparticle inks exhibit highly tunable light scattering properties. Integration of spray-deposited ZnO films into GaAs photovoltaics results in increased short-circuit currents and efficiencies owing to the texture-induced absorption and anti-reflective properties of the nanostructured ZnO films.

Keywords: Materials Science and Engineering.
Advisor: Salleo Alberto
Brongersma Mark L. advisor. Thesis advisor
Chan Emory
Synthetic studies on the bis-guanidinium toxin zetekitoxin AB [electronic resource]

Zetekitoxin AB (ZTX) is a bis-guanidinium toxin isolated from the skin of the Panamanian golden frog, Atelopus zeteki. The structure of this molecule has only recently been elucidated, and these studies have revealed ZTX to be structurally related to the marine toxins (+)-saxitoxin and (+)-gonyautoxin 3. Two key structural features distinguish ZTX from other bis-guanidinium toxins - a bridging lactam containing a 3,4-disubstituted isoxazolidine, and an N-hydroxycarbamate substituent on the five-membered guanidine. Synthetic efforts were undertaken to construct this complex natural product. Synthesis of the tricyclic core of ZTX was initially accomplished according to a previously described route to (+)-gonyautoxin 3. Key improvements to this route include the use of biphasic reactions conditions for the coupling of L-serine methyl ester with pyrrole-1-carboxylic acid chloride, and the identification of the 2,2,2-trichloroethoxycarbonyl (Troc) group as a suitable guanidine protecting group. These advances have increased material throughput and enabled exploration of a variety of novel chemistries for advancement of material toward ZTX. As part of these studies, a novel N, S-acetal [2,3]-sigmatropic rearrangement was identified. Subsequent elaboration of the resultant allylic alcohol has led to the synthesis of a novel C10-substituted analogue of saxitoxin. A second strategy for access to ZTX the use of a trialkylsilyl-substituted pyrrole starting material in a selective, intramolecular iminium ion cyclization reaction. The bicyclic product afforded from this reaction positions the trialkylsilyl group at the desired C11 position for further elaboration to the tertiary alcohol moiety found in the natural product. Advancement of the bicyclic product to a silyl-substituted allylic alcohol was accomplished using an N, S-acetal [2,3]-sigmatropic rearrangement. Oxidation of this material yielded an alpha-hydroxy ketone as a result of a directed epoxidation-Brook rearrangement reaction sequence. Cerium(III)-mediated addition of a methyl anion to this C11-ketone has provided a proof-of-principle for establishing the requisite C11 tertiary alcohol. Accordingly, synthesis of the bridging lactam of ZTX can be accomplished through nucleophilic addition of an isoxazoline-derived enolate to the C11 ketone. This strategy for the assembly of ZTX has laid the foundation for future construction of this challenging toxin, and lessons learned along the way may also aid in synthesis of novel bis-guanidinium toxin analogues.

Keywords: Chemistry.
Advisor: Du Bois Justin primary advisor. Thesis advisor
Trost Barry M. advisor. Thesis advisor
Wender Paul A. advisor. Thesis advisor
Systems of mass denunciation [electronic resource]

The act of one individual accusing another to political or religious authorities for transgressions against those authorities—denunciation—is a recurring and ubiquitous phenomenon throughout human history. Mass denunciation, where denunciations largely characterize the relationship between commoners and elites, has existed in places including Germany, the Soviet Union, Italy, Spain, North Korea, China, Guatemala, The Dominican Republic, Argentina, Libya and more. In this dissertation, I develop a general theory of how these systems are implemented, how they function, and what motivations lead individuals to denounce. I focus particularly on voluntary systems of mass denunciation, where individuals are not pressured or coerced (either overtly or subtly) into denouncing, yet there is still widespread participation. To this end, I examine four separate case studies—the Spanish Inquisition, the Salem Witch Trials, Romanov Russia, and Nazi Germany—and find widespread agreement in both their institutional structures and individuals' motivations to denounce. In such settings, I find that mass denunciation involves an uneasy cooperation between elites and commoners, as elites provide the institutional framework making denunciation possible, and commoners supply the denunciations, though they often co-opt the system for their own purposes. The primary motivation on the elite side is usually to control the population in order to stabilize a new regime and consolidate power. On the commoner side, the primary motivation is to punish those they dislike. Systems of mass denunciation are complex, almost paradoxical political regimes in that they lead to greater government control over the society as a whole, while empowering individual citizens to serve almost as individual judges, to punish those they choose at will.

Keywords: Sociology.
Advisor: Granovetter Mark S. primary advisor. Thesis advisor
Cook Karen S. advisor. Thesis advisor
Parigi Paolo
Tapping in [electronic resource] : understanding how Hispanic-Latino immigrant families engage and learn with broadcast and digital media

This dissertation explores how seven low-income Hispanic-Latino immigrant families with young children use broadcast and digital media -- sources that have become a substantial part of families' language and literacy environment but whose role is little understood. In particular, this study focuses on media's role in families' language- and literacy- related activities. The study takes a three-pronged approach that includes: ethnographic case studies of seven families; an intervention wherein I distributed a tablet device (iPad) to each case family and documented the role it took on in everyday family life and learning; and case parents' reponses to the Families and Media survey (Rideout, 2014) that was also administered to a nationally representative sample. The case studies provide rich data regarding families' existing media ecologies and practices, while the intervention gives a glimpse of the opportunities and/or challenges a new technology can bring and how families take up new media tools. The study looks at media use from a sociocultural perspective, which includes the ways family members engage with media together and how media relates to a variety of family interactions including joint media engagement (Takeuchi & Stevens, 2011). The findings reveal a variety of practices that families engaged in for seeking knowledge on the Internet, as well as entertainment and play -- many of which included meaningful language and literacy experiences. Media played several roles which included: helping to "bridge" home and school settings, supporting parents in their own studies or careers and facilitating children's interest-driven learning across settings. The iPad intervention led to some new language- and literacy-related practices, based to some degree on the characteristics of the device, but mostly on the quality of the content that was included with the iPad. The new iPad content allowed families to engage in some language- and literacy-related media activities they hadn't done before, including using ebooks and recording their own animated stories. I argue that media is an important focus of study for understanding the language and literacy experiences of Hispanic-Latino immigrant children and that links between media practices and the development of language and literacy skills merit much greater attention than has been afforded in the past. This study shows clear evidence of families' active and strategic forms of pursuing learning at home.

Keywords: Education.
Advisor: Barron Brigid primary advisor. Thesis advisor
Goldman Shelley
Goldenberg Claude
Valdés Guadalupe advisor. Thesis advisor
Targeted and universal preschool [electronic resource]

This dissertation offers empirical evidence for the ongoing debates over targeted and universal preschool. Specifically, I ask: (1) Does universal preschool narrow socioeconomic achievement gaps? (2) To what extent, and under what conditions, does the American public prefer universal to targeted preschool? (3) Is universal preschool better funded and more resilient to budget cuts than targeted? I address each question in its own paper and engage issues of program effectiveness, public opinion, and political economy throughout. The first paper aims to assess whether universal preschool can meet a central goal of targeted early childhood education initiatives—that of addressing early inequalities. I reanalyze four evaluations of universal preschool programs and compute their effects on achievement gaps by socioeconomic status and race. I also analyze enrollment patterns by student subgroup, reasoning that a program with equivalent benefits for all might still narrow gaps if it serves more children from less advantaged families. Overall, I find little systematic evidence to suggest that universal preschool narrows socioeconomic gaps. In the second paper, I design and field two nationally representative public opinion polls. These polls probe general support for preschool, preferences for its targeted and universal forms, and the causes and correlates of these preferences. On average, I find moderate support for preschool and no national preference for its targeted or universal forms. Opinion is conditioned by financial self-interest and egalitarian values: the threat of higher taxation significantly decreases support for universal programs, while support for targeted preschool is unaffected; likewise, Americans with strong beliefs in equal opportunity favor a targeted over universal approach. My third paper examines preschool finance. This paper begins with a political economic framework hypothesizing resource allocation under targeted and universal regimes. It then describes state per-child expenditures on targeted and universal preschool from 2002 through 2011 and compares the effect of the Great Recession on targeted and universal programs using interrupted time series analyses. In all, I find no evidence to support the claim that universalism secures more public resources or exhibits greater resilience to budget cuts in the context of a financial crisis.Together, these papers overturn much of the existing theory and rhetoric employed in service of the preschool debates. In their place, I propose a new theory of targeting and universalism based on that quintessential American value, equality of opportunity.

Keywords: Education.
Advisor: Loeb Susanna primary advisor. Thesis advisor
Reardon Sean F. primary advisor. Thesis advisor
Sniderman Paul M. advisor. Thesis advisor
Stipek Deborah J.
Tea stories [electronic resource] : cultivating indigeneity in South Africa's Western Cape

The story of South African rooibos tea unfolds in the margins. Punctuated with rumors of public fights, political corruption, and corporate greed, it is a story about globalization and isolation, neoliberal economic reforms and post-apartheid politics. It is about 'whiteness' and 'colouredness, ' migrants and indigeneity. Finally, it is story of economic marginality and of the ways these tensions were negotiated and experienced in a rural South African community. Yet, significantly, it is also a story about the crop itself, an indigenous plant with particular qualities that make it valuable and intensely political. Based on more than fourteen months of ethnographic research in South Africa's rooibos-growing area between 2009 and 2013, this dissertation explores the social, political, and ecological relations in the farming of rooibos tea. In this project, I engage debates on race, indigeneity, and natural resources in the context of a commodity that is celebrated for its ecological indigeneity and of people who do not fit easily into the category of culturally indigenous: Afrikaners who espouse a white African indigeneity and 'coloured' people, a South African racial category often considered mixed or impure and denied nativity to anywhere. I argue that farmers came to understand rooibos differently as its economic value rose. Formerly viewed as just a wild shrub, rooibos became a culturally significant product through which local residents measured their sense of indigeneity and, more broadly, their claim to belonging in South Africa. At stake in this context was not the conventional scholarly concept of indigeneity as a binary relationship between people and place. Instead, rooibos farmers expressed a more fluid idea of indigeneity based on a triadic relationship between plant, place, and farmer. With the majority of land still in white South Africans' hands and more than a quarter of the population without work, indigenous claims have taken on growing importance as political rallying points and means of economic survival. At the same time, my research examines the ways that connections between race and natural resources have legitimized political, social, and economic hierarchies. Through what I call a 'critical natural history, ' I show how the rooibos landscape is fraught with political and social tensions: it embodies both violent racial histories of dispossession and celebratory narratives of belonging to a beloved ecosystem.

Keywords: Anthropology.
Advisor: Ferguson James primary advisor. Thesis advisor
Ebron Paulla A.
Malkki Liisa H. (Liisa Helena) advisor. Thesis advisor
Meskell Lynn advisor. Thesis advisor
Technological determinism and medium ontology in film and early video [electronic resource]

This dissertation examines the unexplored relationship between film and early video. While video and film cultures of the sixties and seventies frequently sought to separate themselves, I consider the two mediums in constellation to reveal a series of tandem concerns and effects. In their investigation of liveness and self-awareness with the forms and operations of video, seminal artists Frank Gillette, Ira Schneider, and Paul Ryan displayed a formalism that was contemporaneously theorized in avant-garde film and minimalism. The early work of Nam June Paik shares with the structural films of Paul Sharits a fascination with technological dysfunction and obsolescence. Jud Yalkut's exemplary videofilms probe the boundary between film and video mediums to investigate a cultural preoccupation with authenticity in an environment increasingly mediated by electronic communications. In delineating these point of conjunction I make two arguments. First, I claim that this constellation of film and early video destabilizes traditional notions of an immanently defined medium, thereby making the film/video configuration a signal moment in the development of intermedia. By focusing on the shared operations and subject effects of film and early video rather than intrinsic qualities, I reconsider the medium as something contingently defined by its variable processes and results rather than its morphology. Contrary to some conceptualizations of intermedia as a fusion of mediums or a disregard for medium, the concurrence of film and video I research characterizes intermedia as a considered analysis of how differentiated mediums interact. To consider film and video together as intermedia is to recognize that while they both form and inform their objects in particular ways, their interaction reveals something unique about their effects that could not be ascertained by considering them separately. My second argument complicates the technological determinism that runs through these artists' work and has been used to criticize their practices. Immersed in the culture of McLuhan, information, and cybernetics, my artists often celebrated their technology as a powerful ameliorative to problems caused by the social, political, and economic order. For these artists, using and watching video was sufficient to alter and direct social and political processes. Though they never explicitly attack the socio-political order or structurally consider their technology's ties to the masters that developed and purposed the technology, they do refashion video with contrary intentions and ends. By drawing on film theory and considering film and video together as dominant cultural media that organize our perception and world, I show how the divergent practices of these artists meaningfully critique the socio-political order even as they work within the confines of that order.

Keywords: Art and Art History.
Advisor: Lee Pamela M. primary advisor. Thesis advisor
Bukatman Scott
Ma Jean
Mesch Claudia advisor. Thesis advisor
Technologies for needle manipulation in magnetic resonance image (MRI)-guided interventions [electronic resource]

This work addresses the challenges of MRI-guided interventions, with methods to manipulate and monitor instrumented tools inside the scanner bore. The work includes a shape-sensing biopsy needle with fiber Bragg grating (FBG) sensors that allows for 3-D estimation of the needle profile. The shape information is used to autonomously control the imaging plane of an MRI-scanner such that the tool tip and target are always in view. Next, a tip-force sensing needle utilizing FBG sensors is presented, which allows physicians to feel whether an interventional tool is contacting objects or piercing membranes. An initial study uses a haptic display method to compare feedback from FBG sensors at the needle tip to forces measured by an external sensor at the needle base. Preliminary results with the haptic feedback system showed that users were able to predict membrane puncture inside tissue phantoms with the FBG-based feedback better than with feedback based on the external sensor. Finally, a parallel master/slave mechanism is presented for inserting and steering a needle from outside the scanner bore for minimally invasive procedures in the prostate. This passive manipulator has two moving platforms, with dimensions chosen for MRI-guided interventions in the pelvis. Further contributions include kinematic and friction analysis to establish design parameters, and an experimental assessment to prove efficacy of the device with respect to expected force transmission behavior.

Keywords: Mechanical Engineering.
Advisor: Cutkosky Mark R. primary advisor. Thesis advisor
Daniel Bruce (Bruce Lewis) primary advisor. Thesis advisor
Okamura Allison advisor. Thesis advisor