Thesis (M.A.)--Texas State University-San Marcos, 2007. / Vita. Appendices: leaves 77-90. Includes bibliographical references (leaves 91-94).

Thesis (M.A.)--Texas State University-San Marcos, 2007. / Vita. Appendices: leaves 77-90. Includes bibliographical references (leaves 91-94).

This dissertation presents a study of hyperbolic turbulence modelling for the Gaussian ten-moment equations. In gaskinetic theory, moment closures offer the possibility of deriving a series of gas-dynamic governing equations from the Boltzmann equation. One typical example, the Gaussian ten-moment model, which takes the form of hyperbolic-relaxation equations, is considered as a competitive model for viscous gas flow when heat transfer effects are negligible. The hyperbolic nature of this model gives it several numerical advantages, compared to the Navier-Stokes equations. However, until this study, the application of the ten-moment equations has been limited to laminar flows, due to the lack of appropriate turbulence models. In this work, the ten-moment equations are, for the first time, Reynolds-averaged. The resulting equations inherit the hyperbolic balance-law form from the original equations with new unknowns, which require approximation by turbulence models. Most of the traditional turbulence models for the Reynolds-averaged Navier-Stokes equations are not perfectly well-suited for the Reynolds-averaged ten-moment equations, because the second-order derivatives presented in these models can break the pure hyperbolic nature of the original model. The relaxation methods are therefore proposed in this project to reform the existing turbulence models. Two relaxation methods, the Chen-Levermore-Liu p-system and Cattaneo-Vernotte models, are used to hyperbolize the Prandtl’s one-equation model, standard k-ε model and Wilcox k-ω model. The hyperbolic versions of these turbulence models are first shown to be equivalent to their original forms. They are then coupled to the Reynolds-averaged ten-moment equations to build the overall hyperbolic governing equations for turbulence flows. An axisymmetric version of Reynolds-averaged ten-moment equations is also derived. A dispersion analysis is conducted for the resulting governing equations, which shows the corresponding dispersive behaviour and stability. The effect of the relaxation parameters is investigated through several numerical tests. All derived turbulence models are applied to solve canonical validation test problems, including two-dimensional planar mixing-layer, free-jet and circular free-jet. The numerical evaluations are analysed and compared against existing experimental measurements.

Background: 33.6% of all deaths in America are caused by cardiovascular disease. An estimated 82.6 million adults (>1 in 3) in America have some form of cardiovascular disease. There were over 400,000 bypass surgeries requiring open-heart surgery. Sternal dehiscence is associated with a morbidity rate of over 47% if mediastinitis supervenes. A rigid closure is required to avoid healing complications, and wire, plates, and bands are all used in an attempt to make a better closure. The purpose of this study it to compare multiple closures and validate a new testing method. Methods: Polyurethane foam blocks will be used, as an alternative to cadavers, to provide homogeneous samples to test and compare multiple closure techniques. Each closure was performed by an engineer after instruction from a cardiothoracic surgeon and the SternaLock plate manufacturers. Seven different closure techniques (single suture, double suture, figure-eight suture, Robicsek weave, Sternalock Silver, Sternalock Blu, and Sternalock Wide Ladder) were compared in both lateral distraction and longitudinal shear. Statistical analysis was used to show the differences in stiffness, yield force, failure force, and yield displacement of each closure method. Results: Under lateral distraction, double wire closure showed the greatest stiffness followed by the Sternalock plates. The Sternalock plates had the greatest failure and yield forces, whereas the double wire performed significantly poorer. The longitudinal testing revealed that the wires provide no resistance to the shearing forces on the sternum, but the screws for plates can allow for multidirectional loading. Conclusions: Overall Sternalock plates are less likely to fail in all directions compared to wired closures. Even though double wire closures displayed a higher average lateral stiffness, the high stress concentrations created by wires allowed for easy foam cutting and much lower yield force and failure force. Testing using foam blocks as sternal analogues produces highly reproducible results, with less variance than cadaveric tests.

Thesis (M.A.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 81-87). Also available on the World Wide Web.

Thesis (M.S.)--Naval Postgraduate School, 2002. / Thesis advisor(s): John E. Mutty, Joseph G. San Miguel. Includes bibliographical references (p. 59-61). Also available online.

Thesis (M.S.)--Naval Postgraduate School, 2002. / Title from title screen (viewed July 18, 2003). Includes bibliographical references (p. 59-61). Also issued in paper format.

Thesis (Ph. D.)--Montana State University--Bozeman, 2004. / Title from PDF t.p. (viewed on June 12, 2006). Chairperson, Graduate Committee: Daniel Goodman. Includes bibliographical references (p. 189-207).

Programming language evolution provides room for improving existing programs. Developers can upgrade their projects, applying new features available in the latest language versions. However, during maintenance activities, the code artefacts can become distant from their original conception. In this context, the use of transformation techniques and processes can be interesting, as it reduces the error-proneness when improving source code structure. Refactoring is a process of improving the design of a software system, modifying its internal structure without changing its external observable behavior. From this scenario, this work presents a refactoring catalog focused on the new features of the Java language. Such refactorings are related to lambda expressions and seek to allow the transformation of features implemented in Java 7 for the current version 8. To evaluate the proposed refactorings applicability, we developed a static analysis and used it in a set of open source projects aiming to search for opportunities to apply those refactorings. / A evolução de uma linguagem de programação fornece espaços para melhorias de programas existentes. Dessa forma, desenvolvedores podem atualizar projetos de sistemas de software, aplicando os novos recursos disponíveis na linguagem. No entanto, ao adaptar, melhorar e modificar um sistema de software, seu código pode se afastar de sua concepção original. Nesse contexto, o uso de técnicas e processos de transformação pode ser interessante, pois reduz a possibilidade de erros ao realizar uma melhoria em uma estrutura de código, por exemplo. A refatoração é um processo de melhoria do projeto de um sistema de software, que altera sua estrutura interna, sem modificar seu comportamento externo observável. A partir desse cenário, este trabalho tem como principal objetivo apresentar um catálogo de refatorações direcionadas às novas funcionalidades da linguagem Java. Tais refatorações estão relacionadas às expressões lambda e visam permitir a transformação de construções implementadas em Java 7 para sua atual versão 8. Para avaliar a aplicabilidade das refatorações propostas, um conjunto de projetos de código aberto foi submetido a uma ferramenta de análise estática, desenvolvida para realizar buscas por oportunidades de refatoração.

This thesis analyzes American basing structure in Germany, in a new political environment at the beginning of the 21st century. The end of the Cold War changed the political and strategic situation in Europe and the substance of American military presence in Europe. The War on Terrorism suggests that the current threats are dynamic and unpredictable and the idea of a permanent U.S. basing structure in the heart of Europe should be reconsidered. Specifically, this thesis describes the reasons for restructuring the large and expensive base structure in Germany and the impact of American withdrawal to the German society. Moreover, this thesis presents new challenges and opportunities for American military presence in other parts of European continent. Finally, this thesis reviews the development of U.S. policy concerning present and future base structure in Europe.