Thesis (D. Min.)--Catholic Theological Union at Chicago, 2003. / Includes abstract and vita. Includes bibliographical references (leaves 142-146).

Ce travail de thèse est une contribution à l’analyse de bifurcation des écoulements fluides avec prise en compte des interactions fluide-structure. Les phénomènes d’instabilité en interaction fluide-structure apparaissent dans de nombreux domaines de la vie courante ou industriels comme, par exemple : le flottement d’un drapeau dans le vent ou bien l’écoulement au sein d’échangeurs thermiques sur les sites de production d’énergie, l’écoulement autour des câbles sous-marins pour l’extraction de matières premières ou la fixation des plateformes off-shore, l’écoulement autour des structures aéronautiques ou navales. Dans ces situations, un phénomène complexe de vibration des structures induite par vortex peut se produire. L’objectif de la thèse est de proposer un algorithme permettant l’analyse de stabilité de tels systèmes. Ainsi, le couplage original d’une méthode de perturbation d’ordre élevé (Méthode Asymptotique Numérique - MAN) à une discrétisation spatiale permettant la prise en compte des interactions fluide-structure est proposée. À cet effet, une description purement eulérienne du mouvement est retenue. L’interaction fluide- structure est décrite au moyen d’une méthode de frontières immergées (MFI) à forçage continu (méthode de pénalisation) et discret (méthode Ghost-Cell). La présence d’obstacles au sein de l’écoulement est obtenue au moyen de la méthode de Level-Set. En complément, un intégrateur temporel des équations du mouvement associant la MAN, la MFI et une technique d’homotopie est proposé. L’ensemble de ces algorithmes est appliqué à des problèmes d’écoulement incompressible, à faible nombre de Reynolds, d’un fluide visqueux newtonien en présence d’obstacles solides rigides (fixes ou mobiles). L’analyse de stabilité d’un écoulement dans une conduite avec expansion/contraction soudaine (bifurcation stationnaire), et autour d’un cylindre (bifurcation de Hopf) est traitée. L’analyse transitoire d’un écoulement autour d’un cylindre rigide et mobile est également proposée. Les résultats obtenus permettent d’évaluer la précision et la performance des algorithmes proposés. Ainsi, les résultats de cette thèse permettent de conclure sur le bien-fondé de l’approche et constituent une première étape vers l’analyse de stabilité d’écoulements en présence de structures complexes, représentatifs de situations réelles / This thesis is a first contribution to the bifurcation analysis of fluid flows by taking into account fluid-structure interactions. Instability with fluid-structure interactions appears in many areas of everyday life or industry such as, for example: flag floating in the wind, flow within heat exchangers for energy production, flow around submarine cables for the extraction of raw materials or the fixing of off-shore platforms, flow around aeronautical or naval structures. In these situations, complex vortex-induced vibrations of the structures can occur. The aim of the thesis is to propose an algorithm allowing stability analysis of such systems. Thus, an original coupling of a high order perturbation method (Asymptotic Numerical Method - ANM) to a spatial discretization which takes into account fluid-structure interactions is proposed. For this purpose, a purely Eulerian description of the motion is retained. Fluid-structure interaction is described using an immersed boundary method (IBM) with continuous forcing (penalization method) and discrete (Ghost-Cell method) forcing. The presence of bodies within the flow is obtained by means of the Level-Set method. In addition, a time integrator of the governing equations associating ANM, IBM and homotopy technique is proposed. All these algorithms are applied to analyse incompressible flows, at low Reynolds number, of a Newtonian viscous fluid in the presence of rigid solids (fixed or moving). Bifurcation analysis of flows in a channel with sudden expansion / contraction (stationary bifurcation), or around a cylinder (Hopf bifurcation) are carried out. Transient analysis of a flow around a moving rigid cylinder is also proposed. Our results make it possible to evaluate accuracy and performance of the proposed algorithms. Thus, thesis results allow to conclude on the validity of the proposed approach. Finally, this thesis work constitutes a first step towards flow stability analysis in the presence of complex structures, representative of real situations.

TEETH AND OTHER TALES is a novella and a collection of short stories that explore the blurry lines between illusion and reality. Teeth, the novella, is narrated backward in time, chronicling the life of Lucy from the age of sixty-five back to seventeen. After years of surviving an oppressive marriage, Lucy escapes her husband, but in doing so abandons her three children. In order to rationalize her decisions, Lucy uses selective memory to create her own reality to the extent that she comes to believe her own delusions. The four short stories in the collection feature protagonists who create their own personal myths and struggle to protect their distorted truths, with mixed results. These struggles between the “real,” as conventionally defined, and personal fictions are complicated by elements of magical realism and surrealism. The stories were influenced by the short fiction of Nikolai Gogol, Franz Kafka and Haruki Murakami.

This study examines how a music band can manage to build an image and story using social media platforms after the infamous break of the golden era. To put it further into perspective, the second part of the study focuses on the fans’ connection to the band and how they use social media themselves. The purpose of this study is, through interviews, qualitative content analysis and rhetorical analysis, to explore how a band successfully use social media to keep their fans’ anticipation alive. To explore my purpose, I have conducted and analysed qualitative interviews. In the analysis section, the data has been interpreted in relation to theories of star image, participatory fandom and the live experience as well as compared to previous research while connecting my own analysis to it. The study discusses tendencies shown in the results when analysing posts from Ghost’s official Facebook page, as well as how participatory fandom as we know it may be at risk, as social media giants keep growing and eliminating other forums that have been vital to fans.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18793号 / 理博第4051号 / 新制||理||1583(附属図書館) / 31744 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 田中 貴浩, 教授 中村 卓史, 教授 高柳 匡 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

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Traditional views of food web dynamics have characterized species interactions as linear and direct. However, modern food web theory suggests that interactions can also be nonlinear and indirect, so that disturbance at one trophic level is transmitted throughout the community. Many previous studies have demonstrated that the removal of top predators from terrestrial ecosystems can have broad-scale impacts on community ecology. I examined the direct and indirect effects of raccoon removal from sea turtle nesting beaches in east-central Florida during the summers of 2003 and 2004. Raccoon and ghost crab predation are among the highest causes of egg mortality for sea turtles in Florida and raccoons are intraguild predators of ghost crabs. Because of the damage done to sea turtle nests, raccoons have been removed from some beaches during the sea turtle nesting season. I compared the diet and demography of a raccoon population that had experienced two decades of raccoon removal to a population that had previously been unmanipulated. I found that long-term raccoon removal had created a significantly male-biased sex ratio in that population. I also examined the indirect effects of raccoon removal by comparing the abundances of raccoons and ghost crabs at four study sites using passive tracking plots. My data suggest intraguild predation by raccoons limits ghost crab abundance and that reduced raccoon abundance allowed ghost crab abundance to increase, resulting in a net increase in sea turtle egg predation. These results support my hypothesis that intraguild predation of ghost crabs by raccoons is an influential interaction on sea turtle nesting beach community dynamics.

The number of dynamics needed to model the motion between a Chief and Deputy satellites has grown greatly since the introduction of the Hill, Clohessy-Wilshire (HCW) equations of motion were introduced. The models have grown to include various things like perturbations, specifically drag, J2, and solar radiation pressure. Dynamics models have also been developed that use True Anomaly as the independent variable instead of time. A lot of work has been put forth to also include cases where the Chief is in an eccentric orbit. While these models have increased the fidelity of relative dynamics these models become very complicated to implement. That is why the HCW equations remain extremely popular after all these developments. However, their simplicity causes issues when there is In-Track separation between the Chief and Deputy satellites. The error in the dynamics increases as this separation increases which leads to a typical constraint that the separation between the Chief and Deputy needs to be much smaller than the radius of the Chief's orbit. That is where this works starts, by examining into ways to increase the accuracy in the HCW equations as the In-Track separation between the Chief and Deputy grows. In which, this will be done by using a curvilinear coordinate system. Furthermore, a technique of using a Virtual Chief satellite will by employed to allow for the HCW equations to be valid for cases where the Chief is in an eccentric orbit. / Master of Science / There are many different models that are used to model the relative motion between two satellites. These models vary from low to high fidelity in the different types of perturbation and ranges that they can model. These higher fidelity models because very complex to implement and while useful the low fidelity models are still popular, specifically the HCW equations. This thesis works on making the HCW equations valid for a larger range of cases.

Grotesque elements in literature are often negatively viewed as an author’s attempt to simply twist reality in an effort to shock or entertain the reader. However, as I explain in my critical introduction, this view disregards the potential of the grotesque. It often has a specific purpose within a plot. It reveals things about characters that would not otherwise be exposed. I discuss this function of the grotesque in the works of Flannery O’Connor, Edgar Allan Poe, Truman Capote, and Brad Watson, and then show how these authors’ uses of the grotesque have influenced my own writing. In my collection of short fiction, each story contains grotesque elements that reveal and emphasize my characters’ hopes and fears.

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