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Boston University. University Professors Program Senior theses. / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-02

Megalopolises in the Pearl River Delta, including Guangzhou and Hong Kong, have experienced various degree of ground subsidence. The causes can be divided into two categories: natural subsidence and the human-induced subsidence. Monitoring the ground subsidence can not only help people to find out the distributions in both spatial and temporal fields, but also guide people to minimize the hazard ahead. Thus, it is significant to monitor the ground subsidence accurately, timely and frequently. This dissertation research uses the Environmental Satellite Advanced Synthetic Aperture Radar (ENVISAT ASAR) data received at the Chinese University of Hong Kong Satellite Remote Sensing Receiving Station and SAR Interferometry (InSAR) technology as a powerful tool for large-scale ground deformation monitoring in Guangzhou and Hong Kong areas. / Persistent Scatterer Interferometry (PSI) method is used to detect ground deformation in the urban area of Guangzhou city. A ground deformation rate map with scattered distribution of point targets shows the maximum subsidence (rise) rate as high as -26 to -20 mma-1 (16-21 mma-1 ), implying that the study area is an active zone for ground deformation. Based on the point target map, a contour ground deformation rate map is generated. All the six ground collapse accidents that occurred in 2007-2008 fall within the subsidence zones, qualitatively validating the IPTA results. Ground subsidence and geological conditions on Datansha Island are examined. The results indicate that the local geological conditions and underground engineering projects are responsible for ground subsidence and ground collapse accidents occurred there. To interpret the distribution of active ground subsidence zones, a local geological map is used as a reference for generating a series of thematic maps. The results show that geological faults, rock distribution, over-development, and underground engineering projects may be four factors leading to the distribution of the active ground subsidence zones. / The Hong Kong International Airport (HKIA) was built on a site of 12.5 km2, of which 75% is reclaimed foundation. Thus, the stability of ground foundation of HKIA is of public concern. I use the PSI method and ENVISAT ASAR data to detect the residual settlement rate from 19 April 2006 to 9 January 2008. I use ground truth data to develop empirical correction models for correcting systematic biases in the ASAR PSI-detected settlement rate. The corrected data follow the Lorentz distribution well, implying that the residual settlement process is dominated by two modes or categories of settlement rates. I find unreasonable positive values of the ASAR PSI-detected annual ground settlement rate, which follow a normal distribution. I draw a scatter plot with ground deformation rate value and coherence value of each point targets. Point targets with lower coherence values and greater positive values are extracted and drawn on a geographical map. Most of these point targets are located at the airport Midfield, which is under construction. A ground settlement rate map of HKIA shows that an area of the Passenger Terminal Building, and an area of the Southern Runway are two relatively stable areas, and one major continuous settlement area covers the airport Midfield. General spatial distribution patterns of ASAR PSI-detected ground settlement rate agree well with model-predicted residual settlement rates. / Zhao, Qing. / Adviser: Lin Hui. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 147-163). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Another interesting area we investigate is topology optimization with geometric control. Our initial research interests in topology optimization with geometric width control were motivated by the challenge of how to get more manufacturable compliant mechanism designs for MEMS devices. Considering MEMS fabrication technologies, say LIGA, it is natural that designs with specified feature width are more preferable with respect to those with free-form geometries. We propose a variational approach to this problem. A novel quadratic energy functional is employed to govern the geometric feature width of the design. This geometry describing functional is added to the performance-describing functionals. In this way both the performance and the geometric width of the design are optimized simultaneously. The preliminary results show that this method is capable of generating strip-like (or beam) designs with specified feature width, which is a highly desirable characteristic and uniquely distinguishes the proposed method. / Compliant mechanisms are involved in many applications both in the macro and in the micro world. But for a long time, the design procedure of compliant mechanisms was rather a handicraft than a technology. The conventional way is made on an ad hoc basis which to a large extent depends on the designers intuition, experience and inspiration. The limitations of such a trial-and-error approach are obvious: it is not always guaranteed to work, especially when the design is very complicated or when topology and multi-material problems are taken into account. The practical design and application of compliant mechanisms are in need of a systematic approach to create conceptual design. Here, we take a level-set-based new approach to solve this problem. / Considering the actual requirements on reliability, we also investigate how to get conceptual designs with distributed compliance, which is the core part of this thesis. We find the intrinsic defects in the widely used spring model and prove that it will inevitably cause designs with both large output displacements and low strain energies. We will show low strain energy does not guarantee high stiffness. To evenly distribute the compliance, we propose a new method considering the "characteristic stiffness" at interested points. In this way, the strength (stiffness) at the output port of the system is involved into the objective function and optimized directly. This new method is applied to some benchmark examples of both structure optimization and compliant mechanism optimization to validate its performance. / In our proposed method, the compliant mechanism design problem is recast as an infinite dimensional optimization problem, where the design variable is the geometric shape of the compliant mechanism and the goal is to find a suitable shape in the admissible design space so that the objective functional can reach a minimum. The geometric shape of the compliant mechanism is represented as the zero level set of a one-higher dimensional level set function, and the dynamic variations of the shape are governed by the Hamilton-Jacobi partial differential equation. The application of level set methods endows the optimization process with the particular quality that topological changes of the boundary, such as merging or splitting, can be handled in a natural fashion. By making a connection between the velocity fields in the Hamilton-Jacobi partial differential equation with the shape gradient of the objective functional, we go further to transform the optimization problem into that of finding a steady state solution of the partial differential equation. / Our research follows the route from ease to difficulty, reflecting our understanding of the compliant mechanism design problem at different stages. The first problem addressed in this thesis is how to maintain the structural connectivity during the topology optimization process. De facto hinges are known to be a fairly typical phenomenon in topology optimization of compliant mechanisms; they represent highly localized compliance regions. A most adverse side effect caused by de facto hinges is that they are prone to cause a structurally disconnected design, especially to that with a low volume ratio. To solve this problem, a digital topological connectivity scheme is integrated within the level set model, which ensures connectivity while allows topology changes. This is our first step in the research process. / Chen, Shikui. / "January 2007." / Adviser: Michael Yu Wang. / Source: Dissertation Abstracts International, Volume: 68-08, Section: B, page: 5513. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 149-162). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

When a moving dot, which is tracked by the eyes and enclosed in a moving framework, suddenly stops while the enclosing framework continues its motion, the dot is seen to describe a curved path. This illusion can be explained only by assuming that extra-retinal signals are taken into account in interpreting retinal information. The form of the illusion, and the fact that the phenomenal path cannot be explained on the basis of positional information alone, suggests that the perceived path is computed by integrating (instantaneous) velocity information over time. A vector addition model embodying a number of simplifying assumptions is found to qualitatively fit the experimental data. A number of follow-up studies are suggested.

Thesis (Ph. D.)--Nottingham Trent University, 2001. / Description based on print version record. Includes bibliographical references (p. 225-242) and index.

The debate over the "globalization" process has been influenced by the emergence of social movements who deplore this process. This research focuses on the French social movement ATTAC (Action for a Tobin Tax for the Aid of Citizens), that criticizes the problematic effects of globalization and of the new European constitutional order. This study contends that anti-globalization movements, such as ATTAC, are not only resisting what is perceived as an unjust economic system (neo-liberal globalization), but also what they perceive as cultural uniformization, or a threat to cultural identity and cultural diversity. I substantiate this claim by studying the membership of ATTAC: through qualitative research, including interviews and observations, I show the multiplicity of discourses in which members address the anti-globalization issue. This study will contribute to the research on transnational social movements, as it demonstrates the prevalence of culture and identity concerns over globalization, something that has been overlooked by previous studies of anti-globalization movements.

This study explores Beckett’s use of physical movements in his plays as part of a strategy to escape the limits of semantic meaning and as an instrument of artistic expression. In a sense, the use of physical movements constitutes a phenomenological, heuristic ‘solution’ to the problem of presentation and representation that Beckett explicitly addresses already in the early 1930s. Drawing out the parallels between Beckett’s dramatic writing and phenomenology, this study seeks to establish the role perception plays in the creative task Beckett set out for himself—namely the realisation of a new means of expression. While Beckett’s careful structuring and de-structuring of movement patterns have not gone unnoticed, the philosophical consequences of Beckett’s ‘assault against words’, has not been fully appreciated. Beckett uses mis-movements not only to ‘desophisticate’ words, but also to expose the means by which the effect of aesthetic perception is produced. This is not to say that mis-movements can be reduced to a set of clear significations—according to Kant “there is no formula that can produce the beautiful”—but to suggest that Beckett uses mis-movements to refocus the audience’s attention on the realm of sensuous perception.

Drawing on newspaper, movement correspondence, and interview data, I examine the tactical selection and (in)visibility of a lesbian and gay student group, Gay Student Services (GSS), in a hostile university campus in Texas from the mid-1970s through the 1980s. GSS was formed to create a safe space for sexual minorities at Texas A & M University (TAMU) and asked university officials to recognize the group officially after physical threats of violence became real. After long delays, when TAMU administrators declined GSS's request, GSS filed a lawsuit against TAMU with the goal of achieving formal recognition. In the first chapter, I offer a brief history of GSS and introduce my thesis structure. In the second chapter, I show how early access to legal aid bolstered GSS members' understanding of their rights and encouraged their use of legal tactics. A sense of legal entitlement also encouraged GSS to pursue legal tactics in the face of administrative antagonism. The hostile campus environment also motivated GSS to utilize legal tactics instead of engaging in more traditional forms of contention, such as protest, to pursue their goal of gaining official status on campus.