Wu, Yi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 74-80). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Constraint Satisfaction Problems --- p.1 / Chapter 1.2 --- Weighted Constraint Satisfaction Problems --- p.3 / Chapter 1.3 --- Motivation and Goal --- p.4 / Chapter 1.4 --- Outline of the Thesis --- p.5 / Chapter 2 --- Background --- p.7 / Chapter 2.1 --- Constraint Satisfaction Problems --- p.7 / Chapter 2.1.1 --- Backtracking Tree search --- p.8 / Chapter 2.1.2 --- Local consistencies in CSP --- p.11 / Chapter 2.2 --- Weighted Constraint Satisfaction Problems --- p.18 / Chapter 2.2.1 --- Branch and Bound Search --- p.20 / Chapter 2.2.2 --- Local Consistencies in WCSP --- p.21 / Chapter 2.3 --- Global Constraints --- p.31 / Chapter 3 --- Tractable Projection-Safety --- p.36 / Chapter 3.1 --- Tractable Projection-Safety: Definition and Analysis --- p.37 / Chapter 3.2 --- Polynomially Decomposable Soft Constraints --- p.42 / Chapter 4 --- Examples of Polynomially Decomposable Soft Global Constraints --- p.48 / Chapter 4.1 --- Soft Among Constraint --- p.49 / Chapter 4.2 --- Soft Regular Constraint --- p.51 / Chapter 4.3 --- Soft Grammar Constraint --- p.54 / Chapter 4.4 --- Max_Weight/Min Weight Constraint --- p.57 / Chapter 5 --- Experiments --- p.61 / Chapter 5.1 --- The car Sequencing Problem --- p.61 / Chapter 5.2 --- The nonogram problem --- p.62 / Chapter 5.3 --- Well-Formed Parenthesis --- p.64 / Chapter 5.4 --- Minimum Energy Broadcasting Problem --- p.64 / Chapter 6 --- Related Work --- p.67 / Chapter 6.1 --- WCSP Consistencies --- p.67 / Chapter 6.2 --- Global Constraints . --- p.68 / Chapter 7 --- Conclusion --- p.71 / Chapter 7.1 --- Contributions --- p.71 / Chapter 7.2 --- Future Work --- p.72 / Bibliography --- p.74

L'influence de la distance de projection sur la microstructure et les propriétés mécaniques de l'alliage Colmonoy déposé par HVOF sur un acier SAE 1045 a été étudiée de manière systématique. La distance de projection varie entre 380 et 470 mm et les revêtements sont étudiés sur la surface et dans une section droite. L'analyse microstructurale est réalisée par MEB et par analyse d'images. Les différentes phases présentes dans le revêtement sont identifiées par diffraction des rayons X. Les contraintes résiduelles de surface sont déterminées par diffraction X en utilisant la méthode des sin[psi], l'analyse étant menée sur la famille de plans {311} de la phase du Nickel à environ 2[théta] ~ 93.2°. Les propriétés mécaniques des revêtements et des systèmes substrat/revêtement sont évaluées au moyen d'essais statiques et dynamiques. La dureté et le module d'élasticité des revêtements sont déterminés par nano-indentation utilisant un indenteur Berkovich et la méthode proposée par Oliver et Pharr. Les limites élastiques des revêtements sont aussi estimées à partir des courbes de chargement suivant la méthodologie de Zeng et Chiu en utilisant un indenteur bille et les équations de Hertz. Les propriétés mécaniques des systèmes substrat/revêtement sont déterminées par des essais de traction et de fatigue-corrosion sur des éprouvettes cylindriques. Les essais de fatigue corrosion ont été réalisés en flexion-rotation à une fréquence de 50 Hz dans une gamme de contraintes appliquées alternées entre 250 et 420 MPa, ceci dans une solution de NaCI à 3%. Les essais de fatigue-corrosion ont été conduits en utilisant des éprouvettes revêtues de chrome dur. / The influence of the spraying distance on the microstructure and mechanical properties of a Colmonoy 88 alloy deposited by means of HVOF thermal spraying onto a SAE 1045 steel substrate has been investigated in a systematic manner. The spraying distance varied between 380-470 mm and the deposits were evaluated both on their surface and cross section. The microstructural study was conducted by means of SEM and image analysis techniques. The different phases present in the deposits were identified by means of XRD. The surface residual stresses of the coatings were also determined employing the sin2[psi] method, the analysis being conducted on the (311) plane ofthe Ni phase, at 2[theta] ~ 93.2°. The mechanical properties of the coatings and substrate-coating systems were evaluated by means of static and dynamic mechanical tests of a different nature. Hardness and elastic modulus of the coatings were determined by means of instrumented indentation employing a Berkovich indenter and the methodology earlier proposed by Oliver and Pharr. The yield strength of the coatings was also estimated from the above curves following the methodology suggested by Zeng and Chiu, as well as from spherical indentation tests and the Hertz equations commonly used in contact mechanics. The mechanical properties of the substrate-coating system were evaluated by means of tensile and corrosion-fatigue tests employing cylindrical samples. Corrosion-fatigue tests were carried out under rotating-bending conditions at a frequency of 50 Hz, in the range of altemating stresses of 250-420 MPa, employing a of 3 wt% NaCI solution. Corrosion-fatigue tests were conducted employing steel samples coated with hard Cr.

Pour étudier les systèmes électromagnétiques, mécaniques ou thermiques, on a de plus en plus recours à la modélisation numérique. Pour la résolution des différents modèles mathématiques, la méthode des éléments finis est généralement utilisée. Dans le cas de couplages multi-physiques, les particularités de chacune des grandeurs étudiées impliquent l'utilisation d'un maillage commun le plus souvent important en termes de nombre d'éléments. L'objectif de ce travail est de proposer et de mettre en oeuvre une méthode de projection de grandeurs discrètes permettant l'utilisation de maillages dédiés pour chacun des domaines de la physique. Dans le premier chapitre, les modèles mathématiques décrivant les phénomènes de l'électromagnétisme, de la thermique et de la mécanique, ainsi que les espaces de discrétisation des différentes inconnues sont exposés. Dans la seconde partie, la méthode de projection est introduite à l'aide d'une interprétation géométrique de la méthode des éléments finis, puis est développée, tout d'abord dans le cas général, puis pour chacun des domaines de la physique étudiés. Des exemples académiques sont également traités dans cette partie afin de valider la démarche utilisée. Enfin, dans le troisième chapitre, la méthode de projection est employée pour modéliser des dispositifs électromagnétiques dans le cas de couplages magnétothermique et magnétomécanique. / To study electromagnetic, mechanical or thermal systems, numerical modelling is more and more used. Generally, to numerically solve the mathematical models, the finite element method is used. ln the case of multi-physical coupling, the properties of each of the studied quantities imply the use of a common meshing which is mostly important in terms of number of elements. The aim of this work is to propound and use a projection method for discrete quantities allowing using dedicated meshes for each phenomenon. ln the first chapter, the mathematical models describing the electromagnetic, thermal and mechanical phenomena, as well as the discretization spaces of each unknown are exposed. ln the second chapter, the projection method is presented through a geometrical interpretation of the finite element method, and then is developed in a general way and for every physical phenomenon. Academicals examples are also modelled to validate the method. Finally, in the third chapter, the projection method is used for the modelling of electromagnetic systems in the case of magnetothermal and magnetomechanical couplings.

We introduce the notion of special spherical symmetry and classify the complete regular minimal surfaces in the three sphere having this symmetry. We also show that the Clifford torus is the unique embedded minimal torus in three sphere possessing special spherical symmetry.

Habil.-Schr.--Marburg--Univ. / Bibliogr. p. [342]-359.

Inaug.-diss.--Basel. / Curriculum vitae. "Verzeichnis der bentitzten litteratur": p. [71].

This thesis explores the ability of global climate models (GCMs) to simulate observed conditions at regional scales by examining probability density functions (PDFs) of daily minimum temperature (Tmin), maximum temperature (Tmax) and precipitation (P). Two new measures of model skill are proposed using PDFs of observed and modelled data. The first metric (Sscore) compares the amount of overlap between the two PDFs. The second metric (Tailskill) is the weighted difference between the PDF tails, where extreme events are represented. The resulting measures of skill are used to differentiate, at a regional scale, between weaker and stronger models. It is investigated whether the weaker models bias future projections given by multi-model ensembles, increasing the uncertainty in the range of projected values and the change from the 20th Century. The Sscore is demonstrated to be robust against inhomogenities found in highdensity Australian datasets, and is a simple and quantitative measure of how well each GCM can simulate all observed events. This methodology is executed for twelve Australian regions of varying climates for all Intergovernmental Panel on Climate Change 4th Assessment Report models for which daily data was available for 1961-2000. Across Tmin, Tmax and P some GCMs perform well, demonstrating that some GCMs provide credible simulations of climate at sub-continental scales. Projections of the annual and seasonal mean and yearly return values over the A2 and B1 emission scenarios are investigated. Models are omitted from an ensemble based on their ability to simulate the observed PDF at regional scales. The stronger models are generally in agreement with the change in mean values, particularly for Tmin and Tmax, though it is shown that they vary in their projections of the yearly return value at least twice as much as projections in the mean values. Lastly, a means-based evaluation method, the Sscore and the Tailskill are employed to differentiate between weaker and stronger models for projections in the 20-year return value of Tmin and Tmax. Weaker-skilled ensembles project larger increases in 20-year return values than stronger-skilled ensembles, such that in some regions for maximum temperature the ensembles are statistically significantly different. Demonstrably weaker models bias projections given by an all-model ensemble and should be excluded so the most reliable estimates of future climate can be obtained.

Thesis (Ph. D.)--University of Washington. / Vita. Bibliography: L. [170]-183.

Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2007. / Includes bibliographical references.

Inaug.-diss.--Basel. / Curriculum vitae. "Verzeichnis der bentitzten litteratur": p. [71].