The primary subject of this thesis is graphene and how the rudimentary attributes of its charge carriers, and local moments on its surface, can be directly manipulated and controlled with electrostatic potentials. We first consider bilayer graphene subject to a spatially varying electrostatic potential that forms two neighbouring regions with opposite interlayer bias. Along the boundary, 1D chiral `kink' states emerge. We find that these 1D modes behave as a strongly interacting Tomonaga-Luttinger liquid whose properties can be tuned via an external gate. Next, we consider superlattices in bilayer graphene. Superlattices are seen to have a more dramatic effect on bilayer graphene than monolayer graphene because the quasiparticles are changed in a fundamental way; the dispersion goes from a quadratic band touching point to linearly dispersing Dirac cones. We illustrate that a 1D superlattice of either the chemical potential or an interlayer bias generates multiple anisotropic Dirac cones. General arguments delineate how certain symmetries protect the Dirac points. We then map the Hamiltonian of an interlayer bias superlattice onto a coupled chain model comprised of `topological' edge modes. We then discuss the relevance of spatially varying potentials to recent transport measurements. This is followed by another study that considers the effect of a magnetic field on graphene superlattices. We show that magnetotransport measurements in a weak perpendicular (orbital) magnetic field probe the number of emergent Dirac points and reveal further details about the dispersion. In the case of bilayer graphene, we also discuss the properties of kink states in an applied magnetic field. We then consider the implications of these results with regards to scanning tunnelling spectroscopy, valley filtering, and impurity induced breakdown of the quantum Hall effect. Finally, we investigate local moment formation of adatoms on bilayer graphene using an Anderson impurity model. We construct various phase diagrams and discuss their many unusual features. We identify regions where the local moments can be turned on or off by applying a external electric fields. Finally, we compute the RKKY interaction between local moments and show how it too can be controlled with electric fields.

The primary subject of this thesis is graphene and how the rudimentary attributes of its charge carriers, and local moments on its surface, can be directly manipulated and controlled with electrostatic potentials. We first consider bilayer graphene subject to a spatially varying electrostatic potential that forms two neighbouring regions with opposite interlayer bias. Along the boundary, 1D chiral `kink' states emerge. We find that these 1D modes behave as a strongly interacting Tomonaga-Luttinger liquid whose properties can be tuned via an external gate. Next, we consider superlattices in bilayer graphene. Superlattices are seen to have a more dramatic effect on bilayer graphene than monolayer graphene because the quasiparticles are changed in a fundamental way; the dispersion goes from a quadratic band touching point to linearly dispersing Dirac cones. We illustrate that a 1D superlattice of either the chemical potential or an interlayer bias generates multiple anisotropic Dirac cones. General arguments delineate how certain symmetries protect the Dirac points. We then map the Hamiltonian of an interlayer bias superlattice onto a coupled chain model comprised of `topological' edge modes. We then discuss the relevance of spatially varying potentials to recent transport measurements. This is followed by another study that considers the effect of a magnetic field on graphene superlattices. We show that magnetotransport measurements in a weak perpendicular (orbital) magnetic field probe the number of emergent Dirac points and reveal further details about the dispersion. In the case of bilayer graphene, we also discuss the properties of kink states in an applied magnetic field. We then consider the implications of these results with regards to scanning tunnelling spectroscopy, valley filtering, and impurity induced breakdown of the quantum Hall effect. Finally, we investigate local moment formation of adatoms on bilayer graphene using an Anderson impurity model. We construct various phase diagrams and discuss their many unusual features. We identify regions where the local moments can be turned on or off by applying a external electric fields. Finally, we compute the RKKY interaction between local moments and show how it too can be controlled with electric fields.

L'objectif de ce travail de thèse est d'étudier l'interaction des ondes électromagnétiques en bande L avec les vagues côtières déferlantes, en particulier pour un observateur situé à proximité de la surface. Le travail s'attache à effectuer une modélisation électromagnétique précise en lien étroit avec le modèle hydrodynamique. Pour modéliser et calculer les champs électromagnétiques diffusés par les vagues déferlantes, nous utilisons une approche numérique par intégrale de frontière, notamment la Méthode des Moments (MdM). Dans ce cadre, nous focalisons le travail sur la problématique de la fiabilité et la convergence du calcul numérique pour des géométries de forte courbure comme peuvent l'être des surfaces de vagues déferlantes. Après une analyse approfondie de la problématique, nous montrons qu'une solution fondée sur la Méthode des Moments d'Ordre Supérieur (MdM-OS) combinée avec la technique de maillage Non Uniform Rational Basis Splines (NURBS) permet d'améliorer les performances de la méthode MdM-Classique. En parallèle du travail de modélisation électromagnétique, nous nous attachons à introduire un modèle hydrodynamique capable de simuler le plus fidèlement possible le mouvement et la déformation des vagues à proximité de la côte. Nous retenons une modélisation hydrodynamique basée sur la Méthode Désingularisée. Cette approche méthodologique nous permet d'étudier l'évolution des vagues en fonction de la pente du fond, de la hauteur relative et de la cambrure des vagues. La combinaison des résultats issus de la modélisation numérique électromagnétique et de la description hydrodynamique permettent ainsi d'évaluer l'évolution des champs électromagnétiques diffusés par les vagues côtières déferlantes en fonction du temps pour trois types de déferlement standard : glissant, plongeant et gonflant.

The rapid growth of financial markets and the increasing diffusion of corporate ownership have placed tremendous emphasis on the effectiveness of corporate governance in resolving agency conflicts within the firm. This study investigates the corporate governance and firm performance/failure relation by implementing various econometric modelling methods to disaggregate causal relations and spurious correlations. Using a panel dataset of Australian firms, a comprehensive suite of corporate governance mechanisms are considered; including the ownership, remuneration, and board structures of the firm. Initial ordinary least squares (OLS) and fixed-effects panel specifications report significant causal relations between various corporate governance measures and firm outcomes. However, the dynamic generalised method of moments (GMM) results indicate that no causal relations exist when taking into account the effects of simultaneity, dynamic endogeneity, and unobservable heterogeneity. Moreover, these results remain robust when accounting for the firm??s propensity for fraud. The findings support the equilibrium theory of corporate governance and the firm, suggesting that a firm??s corporate governance structure is an endogenous characteristic determined by other firm factors; and that any observed relations between governance and firm outcomes are spurious in nature. Chapter 2 examines the corporate governance and firm performance relation. Using a comprehensive suite of corporate governance measures, this chapter finds no evidence of a causal relation between corporate governance and firm performance when accounting for the biases introduced by simultaneity, dynamic endogeneity, and unobservable heterogeneity. This result is consistent across all firm performance measures. Chapter 3 explores the corporate governance and likelihood of firm failure relation by implementing the Merton (1974) model of firm-valuation. Similarly, no significant causal relations between a firm??s corporate governance structure and its likelihood of failure are detected when accounting for the influence of endogeneity on the parameter estimates. Chapter 4 re-examines the corporate governance and firm performance/failure relation within the context of corporate fraud. Using KPMG and ASIC fraud databases, the corporate governance and firm outcome relations are estimated whilst accounting for the firms?? vulnerability to corporate fraud. This chapter finds no evidence of a causal relation between corporate governance and firm outcomes when conditioning on a firm??s propensity for fraud.

The rapid growth of financial markets and the increasing diffusion of corporate ownership have placed tremendous emphasis on the effectiveness of corporate governance in resolving agency conflicts within the firm. This study investigates the corporate governance and firm performance/failure relation by implementing various econometric modelling methods to disaggregate causal relations and spurious correlations. Using a panel dataset of Australian firms, a comprehensive suite of corporate governance mechanisms are considered; including the ownership, remuneration, and board structures of the firm. Initial ordinary least squares (OLS) and fixed-effects panel specifications report significant causal relations between various corporate governance measures and firm outcomes. However, the dynamic generalised method of moments (GMM) results indicate that no causal relations exist when taking into account the effects of simultaneity, dynamic endogeneity, and unobservable heterogeneity. Moreover, these results remain robust when accounting for the firm??s propensity for fraud. The findings support the equilibrium theory of corporate governance and the firm, suggesting that a firm??s corporate governance structure is an endogenous characteristic determined by other firm factors; and that any observed relations between governance and firm outcomes are spurious in nature. Chapter 2 examines the corporate governance and firm performance relation. Using a comprehensive suite of corporate governance measures, this chapter finds no evidence of a causal relation between corporate governance and firm performance when accounting for the biases introduced by simultaneity, dynamic endogeneity, and unobservable heterogeneity. This result is consistent across all firm performance measures. Chapter 3 explores the corporate governance and likelihood of firm failure relation by implementing the Merton (1974) model of firm-valuation. Similarly, no significant causal relations between a firm??s corporate governance structure and its likelihood of failure are detected when accounting for the influence of endogeneity on the parameter estimates. Chapter 4 re-examines the corporate governance and firm performance/failure relation within the context of corporate fraud. Using KPMG and ASIC fraud databases, the corporate governance and firm outcome relations are estimated whilst accounting for the firms?? vulnerability to corporate fraud. This chapter finds no evidence of a causal relation between corporate governance and firm outcomes when conditioning on a firm??s propensity for fraud.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 118-122).

Thesis (M.S.)--Brigham Young University. Dept. of Electrical and Computer Engineering, 2004. / Includes bibliographical references (p. 95-99).

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (p. 115-123).

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains x, 140 p. Includes bibliographical references (p. 137-140). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 114-119).