VictorJuiz/thesis huggingface dataset:
Near-inertial waves in oceanic fronts [electronic resource] : from generation to dissipation
Keywords: Environmental Earth System Science.

The question of how wind-forced near-inertial motions interact with strongly baroclinic upper-ocean fronts, like those occurring in wintertime western boundary current extension zones, is investigated theoretically, computationally and observationally. The investigation considers the full life cycle of near-inertial waves in this context, from generation to dissipation. Winds with frequency content near the local Coriolis frequency accelerate near-inertial motions in the ocean boundary layer. Due to the strong and variable vertical vorticity of the frontal jet, the dominant frequency of the near-inertial motion varies across the front and the horizontal length scales of the oscillations shrink with time. As a result, wave energy radiates into the upper thermocline with an e-folding time scale similar to an inertial period. In the thermocline, wave propagation is substantially modified by the presence of the background flow. Wave energy tends to pile up at turning points and slantwise critical layers where the wave group velocity goes to zero and, in the latter case, the ray tube area also goes to zero. In these regions, numerical models and observations exhibit strong, banded, and coherent wave shear nearly parallel to isopycnals oscillating at a frequency near the local minimum permitted frequency of inertia-gravity waves, which may be less than the local Coriolis frequency. Furthermore, these amplified waves are associated with banded regions of low and in some cases sub-critical Richardson numbers leading to enhanced dissipation and mixing in the thermocline. Three key results emerge from this narrative: 1) Although the dynamics of inertia-gravity wave propagation in strong fronts is qualitatively different from propagation in the absence of a background flow, the essential physics of near-inertial wave propagation can still be characterized by two conservation laws: i) conservation of absolute momentum, and ii) conservation of buoyancy. 2) The strong and variable vertical vorticity of the front facilitates energy exchange between the wave motions and the geostrophic frontal jet. In fact, a large ensemble of wind-generated near-inertial waves always extracts energy from the geostrophic flow on average. With the addition of wave dissipation, the energy loss from the geostrophic flow becomes permanent. 3) The ubiquitous banded near-inertial shear observed in the upper thermocline of the north wall front in the winter Gulf Stream over the course of a month-long observational campaign in the winter of 2012, leads to the conclusion that western boundary current fronts are undersea "surf-zones" for near-inertial waves. That is, in the presence of strong and persistent atmospheric forcing, they are regions of persistently amplified wave shear, strong vertical velocities, enhanced turbulence and mixing.
Network and web security modeling and analysis [electronic resource]
Keywords: Electrical Engineering.

Security modeling and analysis centers on identifying the interaction between three aspects of a system: normal operational behavior, including any security defenses, the system adversary's power, and the properties that constitute system security. In finite-state model-checking, the interactions between system operations and attacker powers can be exhaustively enumerated by an automated tool, allowing security violations to be automatically detected. We use security modeling to analyze the security of DNSSEC network protocol and to design and verify App Isolation, a Web-security technique employing browser-based isolation of web-applications to prevent common attacks such as Cross-Site Scripting, Cross-Site Request Forgery, Session Fixation, etc. We model three levels of the DNSSEC hierarchy using the Murphi model checker and discover a few weaknesses, surrounding the NSEC3 opt-out mechanism and temporal consistency of DNS records, that may allow attackers to inject their records into a DNSSEC system. App Isolation relies on two principles, State Isolation and Entry-point restriction, to provide browser-based protection for high-security web applications, such as online banking. Our modeling, done in the Alloy language, demonstrates that these two principals provided together can effectively mitigate reflected XSS, CSRF, click-jacking, session fixation, and rendering engine hijacking, and that without each other each principal alone cannot prevent attacks from a hijacked rendering engine. In addition to formal checking, we discuss our evaluation of the effectiveness of several commercial black-box Web application vulnerability scanners at detecting common Web application vulnerabilities, both on a synthetic testbed and a set of 27 Web applications built by 9 freelancers and 18 startups. We find that, as a class, black-box web application vulnerability scanners can detect textbook reflected XSS and type-1 SQL-injection vulnerabilities at about 50% success rate, but are ineffective at detected stored vulnerabilities and interpreting client-side languages such as Javascript, both for simple crawling and for vulnerability detection.
Network interface design for low latency datacenter applications [electronic resource]
Keywords: Electrical Engineering.

Ethernet network interfaces in commodity systems are designed with a focus on achieving high bandwidth at low CPU overheads, while often sacrificing latency. This approach is appropriate when software request processing is measured in milliseconds and the interface latency is not an issue. However, recent low latency software efforts in datacenters, such as memcached and RAMCloud, have lowered the software times into the microsecond range. Therefore, the network interface has been promoted into a significant contributor to the overall latency. This thesis presents NIQ: a low latency network interface design optimized for request-response based datacenter applications. NIQ features separate small and large packet interfaces that efficiently send and receive packets with a minimum number of PCIe transitions. A NIQ prototype is built on an FPGA development platform to facilitate the design space exploration and evaluation. The results demonstrate that the proposed interface is capable of 4.7 us application round trip latencies without meaningful negative impact on CPU power or throughput. The NIQ interface supports one independent transmit and receive queue per CPU core, thus enabling datacenter applications reaching higher throughput through parallelization. This thesis argues that multi-threaded multi-queue designs are prone to high latency variance which manifests itself as high tail latency. To combat the high tail latency and further improve the average latency, this thesis presents NeRD: a mechanism for dispatching arriving network requests to the appropriate processor core. NeRD is an application inspired hardware module that combined with NIQ network interface achieves low average and low tail latencies. The NIQ+NeRD combination achieves tail latency improvements by efficiently load balancing requests across processor cores. FPGA prototype results show that under the request load of 80% of maximum, the 95th percentile latency stays within a factor of two of the median latency. Additionally, NeRD provides hardware support for quickly scaling between one and multiple cores, depending on the current request load. The NIQ and NeRD prototype's latency results were found to be heavily dependent on the CPU's power management settings. To quantify the effects of modern power management, an investigation of latency-power tradeoffs was conducted. In particular, this thesis explores the tradeoffs between using interrupts and polling as notification mechanisms.
Neural basis of social status transition in Astatotilapia burtoni [electronic resource]
Keywords: Biology.

Animals display remarkable range in social behavior, despite high conservation of many neurochemicals and their receptors. Even within a species, the social behavior of an individual can vary dramatically depending on environmental and internal cues. What neural mechanisms participate in this flexibility? To investigate the neural basis of social phenotypic plasticity within a species, I used the African cichlid fish, Astatotilapia burtoni, in which adult males can reversibly transition between two strikingly different social phenotypes: subordinate and dominant. In the wild and in the laboratory, these phenotypic transitions predictably follow changes in the social environment. The speed of the behavioral transition from subordinate to dominant outpaces the development of known endocrine and neuroanatomical differences between the two phenotypes. Therefore, I hypothesized that neuromodulation by neuropeptides plays a role in this transition. To test this hypothesis, I took two approaches. First, I focused on a candidate neuropeptide, kisspeptin, a major regulator of reproductive physiology in mammals that has long been suspected to have pleiotropic functions in the brain, and showed a novel role for kisspeptin as a modulator of male social behavior. Second, I used a proxy of neural activity to guide the identification of cell populations responsive to social environment change, and show a behavioral role for the bony fish homolog of oxytocin, isotocin. Both studies indicate a role for neuropeptides in A. burtoni behavioral plasticity. Both studies also suggest my initial question does not have a single answer: neuropeptide modulation is a widespread mechanism for behavioral flexibility, but different variations on this theme have evolved across different lineages. To advance our future investigations with A. burtoni, I also developed successful transgenesis of this species. A. burtoni is not only a behavioral neuroscience model, but is also a member of a vertebrate lineage used to study evolutionary diversification. I discuss how my contribution to the understanding of the proximate mechanisms underlying social behavior within a single species and technical contribution of transgenesis opens future avenues for investigating the neural basis of social behavior variation across species.
The neural mechanisms of decision processes underlying memory retrieval [electronic resource]
Keywords: Psychology.

Episodic memory retrieval can be construed as a set of decision processes in which retrieved event information guides a categorical response. Successful retrieval requires the establishment of cortical representations of event features during stimulus encoding, and the cortical reinstatement of these representations at retrieval. Additionally, retrieval requires neural mechanisms, often thought to be localized in lateral frontal and parietal cortex, to transform these representations into a decision variable that guides action selection. Finally, mnemonic decisions ultimately require the implementation of a motor response. The research described in this dissertation examines several aspects of the neural mechanisms that support mnemonic decision making, with three experiments. The first experiment examines how the strength of categorical representations during initial encoding and during retrieval influences behavioral outcomes of the mnemonic decision. The second experiment employs matched perceptual and memory tasks, to assess commonalities between the neural substrates of mnemonic and perceptual decision making. The final experiment examines retrieval acts made with oculomotor and manual responses, to assess whether lateral parietal activity associated with memory retrieval is specific to manual responses or general across response modalities. Collectively, these studies provide an account for how neural representations, decision processes, and response functions work together to support memory retrieval.
New histories for a new state [electronic resource] : the historical narratives of textbooks and students in Northern Ireland
Keywords: Education.

The three articles of this dissertation explore how the past is represented in history classrooms in Northern Ireland, and the historical understandings students develop as a result. Taken together, these articles help us to better understand the complicated position that narrative holds in the history classroom. When history first appeared on the school timetable in the UK, as elsewhere, its purpose was to communicate a shared national story to new generations. In recent decades, the centrality of the nation in historiography and history education came under attack, both from historians who wrote outside the national mode, and from educationists who argued for greater attention in schools to history as a form of knowledge rather than a body of content. These shifts appear in the changing content and structure of history textbooks in Northern Ireland, which abandon traditional narrative accounts of history in favor of inquiries into significant and controversial events. Students, for their part, also struggle to construct historical accounts that link events together into a coherent whole, and when they do often rely on sectarian templates encountered outside the school. Young people in Northern Ireland encounter multiple and competing versions of the national past. The challenge for history instruction is to provide students with the tools to adjudicate among these competing claims, and the skills to construct coherent and persuasive narratives that explain historical change.
A new materialist archaeology of antimarkets, power and capitalist effects in colonial Guatemala [electronic resource]
Keywords: Anthropology.

This dissertation develops an approach to the archaeology of capitalism within Spanish colonial contexts in Guatemala through the archaeology of San Pedro Aguacatepeque, a multicomponent Kaqchikel Maya community occupied from at least 900-1800 AD. I draw on new materialist and postcolonial theories to craft an archaeology of colonial capitalism that challenges classical trait-based definitions of capitalism which have proven insufficient in studying the Guatemalan colonial context. Working from Braudel and DeLanda's conception of capitalism as a system of "antimarkets", defined as power-manipulated markets, rather than the "free" markets of neoliberal models of capitalism, I attempt to move beyond the baggage-laden and uniquely 19th and 20th century definitions of capitalism that downplay how unequal power affords and sustains the practices and institutions iconic of capitalism. I do so by reorienting analyses toward the unequal power dynamics that undergird the changes in economic engagements and daily practice routinely attributed to the disembodied, abstract influence of Capitalism rather than the human actors and material configurations that catalyze these changes to the benefit of some and the detriment of others. Ceramic and lithic elemental characterization and provenance analysis, documentary research, and palynological analysis provide the bulk of data used to track changes in production and consumption at Aguacatepeque. From this data, I draw out the specific genealogy of the development and reconfiguration of production and consumption practices (namely, increasing market dependence and specialization of production), the antimarkets that afforded and sustained them, and their subsequent effects on practice and experience at Aguacatepeque. In short, this dissertation lays a groundwork for moving beyond static, global north biased models of capitalism and its effects, towards identifying the "actual details of economic history" that better explain the character and direction of change in Spanish colonial Maya economic practices.
New quantum field theory methods for collider physics and strongly coupled systems [electronic resource]
Keywords: Physics.

Searching for new physics requires ever more accurate understanding and modeling of the already known Standard Model of particles. It is also important to know where to look for new physics. In this thesis we will discuss investigations that address each of the aforementioned challenges. To model the dominant QCD backgrounds of the Standard Model more accurately it is important to use exact QCD matrix elements in the parton shower modeling. We will show that a helicity dependent unitary parton shower can achieve efficient matching with exact tree-level QCD matrix elements. The second challenge of knowing where to look for new physics is a daunting task. The Standard Model is a consistent theory all the way up to the GUT scale and using naturalness (absence of fine tuning) as a guideline for where to find new physics is proving increasingly nebulous. To locate physics beyond the Standard Model, we need something that takes us out of the standard model, and this is provided by dark matter. Perturbative unitarity can place interesting bounds on the scale of new physics for any Beyond the Standard Model theory that incorporates dark matter. Using the example of the Next to Minimally Supersymmetric Standard Model (NMSSM), we will show that perturbative unitarity combined with some basic hypothesis about dark matter can tell us where the next scale of new physics could be in a reliable way. In the last part of the thesis, we will discuss how the principle of perturbative unitarity can be applied to strongly coupled systems. A strongly coupled system with conformal symmetry admits an effective description if there is a large dimension gap in the spectrum of the dilatation operator and a parameter such as 1/N that suppresses higher point connected functions. In this case, the three-point current correlation function of a strongly coupled system with conformal symmetry can be calculated from the dual weakly coupled AdS effective theory. The three-point function admits perturbative expansion in the inverse dimension gap. The contribution from the first non-renormalizable bulk operator is computed and shown to lead to a different polarization structure compared to the leading renormalizable operator. This result is used to suggest an experimental probe of the effective description of strongly coupled systems at second order phase transition through an indirect measurement of the the dimension gap.
New York State of Mind: Policing Terrorism in the Empire City
Keywords: Center for International Security and Cooperation
CISAC
Freeman Spogli Institute
FSI
Senior
Thesis
Honors
Policing
Terrorism
Counterterrorism
New York
9/11
Thesis

What factors explain the New York Police City Department’s (NYPD) post-9/11 counterterrorism reforms? The conventional narrative suggests that New York’s counterterrorism strategy has been a direct reaction to the events of September 11th, with the NYPD adapting to address new threats and vulnerabilities. While necessary, this 9/11-centric explanation is insufficient in understanding the scope, scale, and tactics of the NYPD’s counterterrorism strategy. Instead, the evidence suggests that imprinted institutional norms and path dependence within New York policymaking shaped the Department’s response to terrorism. Dating back to the Progressive Era, New York has demonstrated a bureaucratic bias towards internalizing national priorities, resulting in reforms that are consistently at the vanguard of policing tactics.
To advance this institutional argument, this thesis will analyze three key NYPD decision- making nodes: the reformation of a dedicated Intelligence Division, a legal battle to increase the Department’s ability to gather intelligence, and the establishment of a controversial “Demographics Unit.” At all three junctures, the evidence indicates that policymaking was propelled by a bureaucratic tendency to align reforms with national priorities, effectively ‘localizing’ a federal agenda. As a city teeming with strong-willed personalities, this forward-leaning institutional norm was bolstered by a cohort of policy entrepreneurs, eager to buck traditional notions of the role of local policymaking in a federal system. These findings provide a novel understanding of the NYPD, contributing an analytic counterpart to the conventional, event-driven narrative. While September 11th was the initial catalyst for policing reforms, institutional history and organizational behavior are necessary to explain the forward-leaning character and federally inspired content of New York’s response to terrorism.
Ni el problema, ni el remedio (neither the problem, nor the solution) [electronic resource] : Latina immigrant mothers negotiating deficit perspectives in U.S. early childhood education
Keywords: Education.

This dissertation analyzes how a group of Latina immigrant women negotiated U.S. educational ideas and cultural messages in a program called Vamos al kinder (Let's go to kindergarten). Vamos al kinder is a preschool and parent education program for three to five-year-old Spanish-speaking children and their parents in a mid-size town in Oregon. Documenting how staff and mother-participants discussed, developed, and practiced U.S. cultural messages and parent involvement strategies in the workshops brings to light the immense amount of work, care, and love they enacted for their children and community. The dissertation has three principal conclusions. First, Latino families in my study were neither the source of nor solution to their children's potential academic challenges. Second, parent education is a complex, sometimes duplicitous space for low-income parents of color, especially Latina immigrants. Finally, Vamos al kinder and community-based programs like it can provide an alternative parent educational space, through staff's creativity, cariño (affection/care) and connections to grassroots community organizing opportunities, which allow for parent leadership. Despite deficit-oriented tools they inherited from early childhood education, the staff's tenacity in emphasizing parent and family strengths demonstrated the importance of creating safe spaces for Latina immigrant women to foster interactions, discussion, and experimentation among themselves.