VictorJuiz/thesis huggingface dataset:
Increasing the Flow Capacity of Signalized Intersections with Pre-signals: Theory and Case Study

The dissertation proposes a new "tandem design" to reorganize traffic and increase the flow capacity of signalized intersections. In the tandem design, a mid-block pre-signal is used to sort left-turning vehicles (LVs) and through-moving vehicles (TVs) in tandem, rather than leaving them side by side, as in the conventional design. For intersections with separate through and left-turn phases, the tandem design outperforms the conventional one because more lanes can be used to discharge traffic during at least one of the intersection signal phases. We find that the tandem design can increase the intersection capacity by 10% to 20% in its simplest form. We also study the length requirement of blocks to fully realize the capacity benefit, and modifications of the tandem design to reduce this length requirement. We then conduct a case study at a signalized intersection in the city of Chengdu, China. The case study shows that the tandem design can effectively increase intersection capacity. Moreover, the case study shows that together with enforcement of the bus-lane restriction, both cars and buses can benefit./nFinally, we demonstrate how the idea of tandem sorting with pre-signals can be extended to increase intersection capacity of multimodal traffic, using as an example the case of cars and buses. This extension hinges on an assumption that the discharge times of different modes of transport is additive, and this assumption is confirmed with a natural experiment.

Advisor: Daganzo, Carlos F
Cassidy, Michael J
Making Art, Creating Infrastructure: deviantART and the Production of the Web

The development and widespread use of Internet technologies and platforms that are grouped under the labels "Web 2.0" and "social media" have led to celebratory accounts of their potential as tools to unleash human creativity. A "creativity consensus" has emerged that describes a vision of creative production via these new platforms as universal, democratic, communal, non-commercial, and revolutionary. The avant-garde of Web 2.0 creativity are said to be young, web-savvy media makers: a new generation that has embraced new technology and is upending old notions of creativity and related cultural practices. This dissertation challenges these views through an ethnographic investigation of deviantART, the self-described "world's largest online art community." The dissertation demonstrates how conflicting ideals of art, creativity, and the web, when put into practice, shaped the site as ideological and technical infrastructure for creative practice and the formation of members' creative identities. In their use of the site, participants in deviantART actively, and at times contentiously, engaged with historical tensions concerning both art and the web. The dissertation explores tensions emerging around three sets of concerns: (1) gaining artistic recognition through visibility, popularity, or quality; (2) demonstrating artistic "seriousness" in relation to ways of improving at art; and (3) controlling and circulating work through the concepts of property, "sharing," and "theft." The dissertation argues that rather than upending Romantic conceptions of art and creativity, the web uneasily accommodates multiple conflicting ideologies. Intersecting with tensions in art are tensions around the web and its overlapping corporate, commercial, and communal uses. deviantART brought together a diverse set of art worlds and creative practices via a seemingly conventional set of interfaces, features, and functionality. In turn, participants on the site helped manifest, reproduce, and transform these tensions in art practice and web use. These findings illustrate flaws in conventional accounts of creativity in a world with the web--accounts that fail to recognize the active, contested, and ongoing work underlying the mutual production of creative practice and the web.

Advisor: Van House, Nancy
Crossing Borders: Teacher Pedagogical Discourse Practices in a Non-Profit Community Media Center

The communication skills of teachers, their repertoire of discourses and rhetorical tools, are central to successful educational projects. This dissertation analyzes discourses as complex social practices to determine how they contribute to (or inhibit) things like student engagement, effective student learning, and student initiation into professional practices. Through classroom observations and teacher interviews, this qualitative case study illuminates the discourse practices of two teachers at a non-profit youth development media program. It considers how these teachers negotiate the intersectionality of professional radio discourse with other youth discourses to facilitate student learning of complex content as well as technical and journalistic skills. I propose the term Global Emergent Discourse to capture the mixture of diverse cultures and of global and local identities reflected in the classroom communication of these students and their teachers. This is a hybrid discourse that results from the colliding mixes and collages of their lived experiences. The findings of this study indicated that the deployment of discourse by the teachers in this setting was the enactment of an invented hybrid that was neither formal professional English nor the primary community discourses of the students in the two classes. It was a mixture that marked points of unity as well as steps towards induction to new discourses that reached across different generations and different local experiences within the complex web of Global Emergent Discourse. This hybrid discourse allowed these two teachers to effectively engage students in a complex curriculum of journalism, media literacy, and technical skills. It also marked a validation of the perspective and values of both the teachers and the students and stood in contrast to and critique of the one way transmission of knowledge and framing of educational goals that is often reflective of schooling in the United States.

Advisor: Mahiri, Jabari
Tissue Magnetic Susceptibility Matched Pyrolytic Graphite Foam for Improved MRI

In MRI, a powerful and uniform static B0 field is responsible for image signal and contrast. However, regions of different magnetic susceptibilities in the static field give rise to field inhomogeneities that cause image artifacts. For example, air and tissue interfaces for a patient in a MRI study induce up to ±5 ppm static B0 field perturbations within the patient. Unfortunately shim coils are too large to compensate for the very steep field variations found near the breast, cervical spine, shoulders, occipital lobe, and other regions of the body. Many MRI applications are vulnerable to B0 inhomogeneity, including robust fat suppression, which requires better than ±1 ppm homogeneity./nTo address this challenge, we have developed a flexible, conforming composite foam with magnetic susceptibility matched to human tissue. We surround the region with enough matching material to move the field gradients outside of the body where they cannot cause MRI artifacts. Our matching material is a pyrolytic graphite (PG) composite foam. It has many advantages over existing matching agents: it is lightweight; it adds no noise; and it is safe to embed receiver coils within the PG foam./nIn this thesis, we propose theory that describes the magnetic susceptibility matching properties of composite PG foam. We show experimental proof of concept susceptibility matching and safety in phantom experiments. We also experimentally demonstrate that PG foam cushions improve the B0 field uniformity to the critical threshold of ±1 ppm in both phantoms and in the neck of 6 normal volunteers at 3T. The tissue susceptibility matched PG foams consistently mitigate signal drop out, improve image SNR, and enable far more robust frequency selective fat suppression in T1-weighted FLASH images in volunteers. PG foam has many practical applications in MR applications that require a pristine B0 field.

Advisor: Conolly, Steven
Cultural Markings on the Landscape: The PCN Pecked Curvilinear Nucleated Tradition in the Northern Coastal Ranges of California

This dissertation explores the archaeological context of the PCN (Pecked Curvilinear Nucleated) tradition of marking boulders as it appears in the landscape of the Coastal Ranges of Northern California. Located on the over 2150 hectare property of the University of California Hopland Research and Extension Center (HREC) are five boulders or clusters of boulders that exhibit cultural markings, including some cupules, which were placed in the distant past on a specific type of boulder, in distinctive shapes and forms. By using a landscape archaeology and ritual theory framework, I explore the prehistoric activities that took place at the more than 30 identified prehistoric sites, through the archaeological context provided by more than 3000 catalogued artifacts excavated and collected from the sites. After subjecting the data to various technological methods, the results of various archaeological testing (obsidian hydration, chemical sourcing, AMS dates, soil testing techniques, and recording techniques) are reported, discussed and interpreted. A final objective and contribution of this study is to present a contextual model for application to similar archaeological sites.

Advisor: Conkey, Margaret W.
Queue Interactions on an Urban Freeway and Their Influence on Discharge Flow

This thesis unveils a reason for the time-varying patterns in discharge flow that are commonly observed at freeway bottlenecks. Observations reveal that four well-known effects in freeway traffic can interact upstream of a bottleneck in ways that trigger periodic bursts in its discharge flow. A hypothesis concerning the capacity-increasing mechanism is that following an initial "capacity drop", (i) the bottleneck's expanding queue can trigger a new and more restrictive bottleneck further upstream. As a result, (ii) the queue downstream recedes toward the original bottleneck, leaving free flow conditions in its wake. If the tail of this receding queue (iii) passes an on-ramp junction that resides upstream of the original bottleneck, then (iv) a higher bottleneck discharge flow can temporarily ensue. We also hypothesize that this higher discharge rate should diminish after some minutes due to the capacity drop phenomenon. The process would then start anew. Detailed data collected from a 3-km freeway stretch over multiple days support this hypothesis./nThe above suggests that the flow through the bottleneck can be increased by metering the freeway's on-ramps in a coordinated but unconventional way. Experiments with this approach consistently produced long-run bottleneck discharge flows that were higher than those generated from a more traditional metering policy. The average difference over multiple days was nearly 3%.

Advisor: Cassidy, Michael J..
Vision in Ruins

Vision in Ruins explores the practice of art, video, and visuality in an era of globalization. In contrast to past writings on video beholden to its mechanisms and the legacy of western modernism, my inquiry approaches video from a philosophical, postcolonial, and feminist perspective. Sourced to its Latin root, the word video translates as "I see," a statement that illuminates how video encloses a sense of vision that is not only solely bound with the eyes, but is more broadly entwined with the transparency of a subject, its sight, and its presence. Video (I see) is the understanding of vision as an open field, one that is coupled with power and that I relate to both the visualities of modern warfare and liberal thought as it pervades the discourses of art and human rights. Against such understanding of vision as an open field, my dissertation approaches vision as a restricted site. With each assertion of video, I suggest that a boundary is drawn. My dissertation approaches video from the other side of this boundary, from the position of subjects displaced by the political histories of global war, migration and exile, and describes their attempt to rework the field of vision. Rather than treat video as an object, I treat video is as a lens onto the themes of vision, aperture, passage, opacity, disappearance, calling, and ruins. Vision in Ruins problematizes the openness of vision and seeks to write a different story of video. It reworks the visual as one attuned to the conditions of invisibility and unspeakability that often become elided in favor of 'appearance' in the forms of liberal thought. It suggests that when one works from the ruins, one invites a renewal of politicized practice, where appearance is not an object but a modality and where each appearance is also, always, a disappearance. The orientation is not to the 'appearance' of alterity but rather, but to the invisible, the unspeakable, and to the temporality of other life worlds. In order to rethink visuality in an era of globalization, I suggest we must learn to work in a gap between visuality and alterity. It is a gap that shifts art's relation to the cinematic, to war, to human rights, and to conceptions of the global-- all of which I reconsider in light of a visuality of relation that works in a space where what remains invisible and unspeakable might direct us toward a different sense of world and how we see it.

Advisor: Trinh, Minh-ha T.
On Embedding Singular Poisson Spaces

This dissertation investigates the problem of locally embedding singular Poisson spaces. Specifically, it seeks to understand when a singular symplectic quotient V/G of a symplectic vector space V by the linear symplectic action of a group G is realizable as a Poisson subspace of some Poisson manifold (R^n,{ , })./nThe local embedding problem is recast in the language of schemes and reinterpreted as a problem of extending the Poisson bracket to infinitesimal neighborhoods of an embedded singular space. Such extensions of a Poisson bracket near a singular point p of V/G are then related to the cohomology and representation theory of the cotangent Lie algebra at p./nUsing this framework, it is shown that the real 4-dimensional quotient V/Z_n (n odd, Z_n the cyclic group of order n) is not realizable as a Poisson subspace of any (R^(2n+6),{ , }), even though the underlying variety algebraically embeds into R^(2n+6). The proof of this nonembedding result hinges on a refinement of the Levi decomposition for Poisson manifolds to partially linearize any extension with respect to the Levi decomposition of the cotangent Lie algebra of V/G at the origin. Moreover, in the case n=3, this nonembedding result is complemented by a concrete realization of V/Z_3 as a Poisson subspace of R^78.

Advisor: Weinstein, Alan D
New Tools and Approaches for Studying the Role of the Saccharomyces cerevisiae phosphatidylinositol 4-kinase Pik1 in the Yeast Nucleus

Abstract/nNew Tools and Approaches for Studying the Role of the Saccharomyces/ncerevisiae phosphatidylinositol 4-kinase Pik1 in the Yeast Nucleus/nby/nEvguenia S. Klimenko/nDoctor of Philosophy in Molecular and Cell Biology/nUniversity of California, Berkeley/nProfessor Jeremy W. Thorner, Chair/nPhosphoinositides are a specialized type of glycerophospholipids found in all eukaryotes and their levels undergo dynamic temporal and spatial changes mediated by the actions of dedicated phosphatidylinositol kinases, phosphatases, and lipases. The Saccharomyces cerevisiae genome encodes two distinct Type III PtdIns 4-kinases that share sequence homology to each other: PIK1 and STT4. Together, Pik1 and Stt4 account for synthesis of more than 90% of the PtdIns4P detectable in yeast extracts, each is essential for viability, and the inactivation of either Pik1 or Stt4 via conditional alleles results in distinct non-overlapping phenotypes. It is thought that the independent functions of Pik1 and Stt4 result from their localization to specific cellular compartments. In the budding yeast, Stt4 localizes exclusively to the plasma membrane, whereas Pik1 localizes primarily to the Golgi body, but is also found in the cytoplasm and in the nucleus./nFor the first part of my dissertation research (Chapter 3), I have characterized a novel potential specific inhibitor of Pik1. Compound ST016598, dubbed optimistically "pikostatin", specifically inhibits the growth of cells with reduced dosage of PIK1, without affecting Pik1 stability, in vivo protein-protein interactions, or localization of fluorescently-tagged Pik1. Although ST016598 (pikostatin) is only a weak inhibitor of the lipid kinase activity of Pik1 in vitro, pikostatin treatment nevertheless results in a specific, rapid, and reversible depletion of the Pik1-dependent Golgi body-specific pool of PtdIns4P, without affecting the separate pool of PtdIns4P created at the plasma membrane by Stt4. I also found that a subset of pik1ts alleles exhibit hypersensitivity to pikostatin even under permissive conditions, with subsequent implications for the mechanism by which pikostatin might inhibit Pik1 activity at the Golgi body./nPrevious work from this lab used two differentially-localized Pik1 constructs to demonstrate that localization of Pik1 both to the Golgi and to the nucleus is required for viability. However, so far, no attempts have been made to separate the function of Pik1 in the nucleus from its now well-characterized essential function in the Golgi compartment. For the second part of my dissertation research (Chapter 4), I have tested directly whether Pik1 is responsible for generating nuclear PtdIns4P that might serve as the precursor for production of a soluble cofactor (InsP6) that is necessary for mRNA export. I also attempted to apply an unbiased genetic selection for dosage suppressors of the lack of nuclear Pik1 as a means to identify potential phosphoinositide- or inositol-polyphosphate-binding effectors in the yeast nucleus.

Advisor: Thorner, Jeremy W.
Learning and Legislating to Love: Marriage Promotion Policy and Family Inequality in America

In 1996, Congress overhauled welfare policy to encourage work and marriage as routes to economic self-sufficiency for poor American families. This led to the subsequent creation of the federal Healthy Marriage Initiative (HMI) in 2002. The HMI has funded hundreds of relationship skills and marriage education programs across the country, many targeting poor and low-income unmarried couples with children. To date, very little of the social scientific and policy debate over the value of such programs has focused on what relationship skills-based government-sponsored marriage promotion actually involves in practice. To address this gap, this dissertation draws on data collected data during an 18-month participant observation study of one federally-funded relationship skills program for low-income, unmarried parents called Thriving Families, including in-depth interviews with 60 program staff, instructors, and participants./nI find that Thriving Families couples delayed marriage because of a phenomenon I call curtailed commitment, the belief that if they cannot live up to middle-class ideas of family life, including meeting a specific economic threshold, couples are not equipped for marriage. Staff and instructors employed three primary strategies to encourage couples to overcome this reluctance: 1) rather than promoting marriage directly, they promoted a healthy co-parenting relationship, preferably within the context of marriage, as the best resource poor parents have to bolster their children's life chances; 2) they reframed what I call marital masculinity by suggesting that marriageable men are those who have the capacity to be caring co-parents and good communicators, qualities that do not depend on their ability to live up to middle-class norms of male breadwinning; and 3) they tried to teach parents financial management skills that would presumably enable them to have more money and communication skills to help them talk through relationship problems. Though economic constraints challenged their abilities to use the skills promoted by the program, parents viewed the classes as a rare opportunity to communicate free of the material constraints that overwhelmingly characterized their daily lives and their intimate relationships. This suggests that rather than promoting an instrumental view of marriage--that marriage prevents poverty--healthy marriage policy could likely better serve disadvantaged families by acknowledging and addressing the socioeconomic roots of curtailed commitment as part of public efforts to strengthen family relationships.

Advisor: Thorne, Barrie
Engineered Autonomous Nanomachines Using Brownian Ratchets

Nanoscale machines which directly convert chemical energy into mechanical work are ubiquitous in nature and are employed to perform a diverse set of tasks such as transporting molecules, maintaining molecular gradients, and providing motion to organisms. Their widespread use in nature suggests that large technological rewards can be obtained by designing synthetic machines that use similar mechanisms./nThis thesis addresses the technological adaptation of a specific mechanism known as the Brownian ratchet for the design of synthetic autonomous nanomachines. My efforts were focused more specifically on synthetic chemomechanical ratchets which I deem will be broadly applicable in the life sciences. In my work I have theoretically explored the biophysical mechanisms and energy landscapes that give rise to the ratcheting phenomena and devised devices that operate off these principles./nI demonstrate two generations of devices that produce mechanical force/deformation in response to a user specified ligand. The first generation devices, fabricatied using a combination nanoscale lithographic processes and bioconjugation techniques, were used to provide evidence that the proposed ratcheting phenomena can be exploited in synthetic architectures. Second generation devices fabricated using self-assembled DNA/hapten motifs were constructed to gain a precise understanding of ratcheting dynamics and design constraints. In addition, the self-assembled devices enabled fabrication en masse, which I feel will alleviate future experimental hurdles in analysis and facilitate its adaptation to technologies./nThe product of these efforts is an architecture that has the potential to enable numerous technologies in biosensing and drug delivery. For example, the coupling of molecule-specific actuation to the release of drugs or signaling molecules from nanocapsules or porous materials could be transformative. Such architectures could provide possible avenues to pressing issues in biology and medicine: drugs could eventually be triggered to release in the presence of molecular signals indicative of diseased states, early disease detection could be achieved by examining the cell microenvironment then releasing imaging agents and generalized control could exerted over the free molecule signaling networks of cells.

Advisor: Maharbiz, Michel M