Sara Lidman’s first novel, Tjärdalen (The Tar Pit, 1953), addresses ethical issues in a remote village in the north of Sweden. This essay discusses the novel’s narrative technique and the ethical aspects implied by the narration and aesthetic design. The approach is based on Adam Zachary Newton’s narrative ethics, which links narrative theory and method with an ethical perspective. Mikhail Bakhtin’s literary theory and Gérhard Genette’s concept of focalization are starting points for the analysis. The ethical framework is drawn both from Bakhtin and from philosophers Martin Buber and Emmanuel Levinas. This means that responsibility is a more important concept than the collective and individual guilt that has been the focus of some interpretations of the novel. Furthermore, in the essay, the concept of dialogue is both a narrative technique and an ethical position, thus knitting together the different parts of the essay: how ideas, voices, faces and eyes meet and how the village interacts with the outside world. Tjärdalen’s design opens to a polyphonic analysis and the essay examines how the text’s ethical and intersubjective emphasis grows out of the composition – out of the arrangement of scenes and viewpoints. The dialogue between multiple voices continues in the representation of the characters’ inner life. Petrus’ character is constructed as open and questioning, inviting discussion, persuading and arguing rather than dictating. In the essay this way of life is defined as dialogic, as opposed to the monologic positions of characters like Blom and Albert. The essay finds, however, that the strong position of the narrator dilutes the polyphonic pattern. The examination of the narrator explores both her loyalties and the attitudes and worldviews that she rejects. Particular emphasis is placed on the analysis of Jonas’ character, as the plot starts and ends with his eyes. The symbolism of the eyes and of the face forms a parallel structure in the text, giving the ethical discussion a depth not achieved by rational dialogue and reflection. In the essay, this level is interpreted by Levinas’ ethics, where the face and the eyes represent a call to responsibility. At the end of Tjärdalen, the ethical questions are transferred to the wider society outside the village. The analysis explores two lines in this shift: One is how the spatial organisation of the narrative and the unchanging quality of the village life leads to a circular composition. The other is how the text brings social criticism back to its origin in interpersonal relationships: to meetings face to face and to the responsibility for the “other” that, according to Levinas, Buber and Bakhtin, is the basis of these encounters.

This thesis explores the inverse problem of optical tomography applied to two-dimensional heterogeneous domains. The neutral particle transport equation was used as the forward model to simulate how neutral particles stream through and interact within these heterogeneous domains. A constrained optimization technique that uses Newton's method served as the basis of the inverse problem. The capabilities and limitations of the presented method were explored through various two-dimensional domains. The major factors that influenced the ability of the optimization method to reconstruct the cross sections of these domains included the locations of the sources used to illuminate the domains, the number of separate experiments used in the reconstruction, the locations where measurements were collected, the optical thickness of the domain, the amount of signal noise and signal bias applied to the measurements, and the initial guess for the cross section distribution. All of these factors were explored for problems with and without scattering. Increasing the number of sources, measurements and experiments used in the reconstruction generally produced more successful reconstructions with less error. Using more sources, experiments and measurements also allowed for optically thicker domains to be reconstructed. The maximum optical thickness that could be reconstructed with this method was ten mean free paths for pure absorber domains and two mean free paths for domains with scattering. Applying signal noise and signal bias to the measured fluxes produced more error in the reconstructed image. Generally, Newton's method was more successful at reconstructing domains from an initial guess for the cross sections that was greater in magnitude than their true values than from an initial guess that was lower in magnitude.

Nous étudions la stratification de Newton des variétés de Shimura de type PEL aux places de bonne réduction. Nous considérons la strate basique de certaines variétés de Shimura simples de type PEL modulo une place de bonne réduction. Sous des hypothèses simplificatrices nous prouvons une relation entre la cohomologie l-adique de ce strate basique et la cohomologie de la variété de Shimura complexe. En particulier, nous obtenons des formules explicites pour le nombre de points dans la strate basique sur des corps finis, en termes de représentations automorphes. Nous obtenons les résultats à l'aide de la formule des traces et de la troncature de la formule de Kottwitz pour le nombre de points sur une variété de Shimura sur un corps fini. Nous montrons, en utilisant la formule des traces, que n'importe quelle strate de Newton d'une variété de Shimura de type PEL de type (A) est non vide en une place de bonne réduction. Ce résultat a déjà été établi par Viehmann-Wedhorn; nous donnons une nouvelle preuve de ce théorème. Considérons la strate basique des variétés de Shimura associées à certains groupes unitaires dans les cas où cette strate est une variété finie. Alors, nous démontrons un résultat d' équidistribution pour les opérateurs de Hecke agissant sur cette strate. Nous relions le taux de convergence avec celui de la conjecture de Ramanujan. Dans nos formules ne figurent que des représentations automorphes cuspidales sur Gl_n pour lesquelles cette conjecture est connue, et nous obtenons donc des estimations très bonnes sur la vitesse de convergence. En collaboration avec Erez Lapid nous calculons le module de Jacquet d'une représentation en échelle pour tout sous-groupe parabolique standard du groupe général linéaire sur un corps local non-archimédien.

Power losses in the grid are important, and as the power losses decrease the efficiency increases. Not much research has been done recently on the Newton-Raphson Power Flow (NRPF) method in polar form for systems with High Voltage Direct Current (HVDC) subsystems. The point of departure for this thesis is based on decoupling the NR Power Flow method Power flow problems are solved for many fundamental problems in the operation and planning of the power system. Although many methods are available to solve these problems, this thesis focuses on developing an enhanced HVDC power flow method with improved computational efficiency and convergence stability. A comparison of the results with full Newton-Raphson Power Flow method is presented to evaluate the performance of the proposed method. Simulations were conducted on the 14-bus and 30-bus IEEE systems. Two and three converters are shown to improve the voltage magnitude, active and reactive power profile .The overall results indicate which mode is the best mode compared to others depending on the bus importance.

Pulsar wind nebulae (PWNe), nebulae harbouring a rotation-powered neutron star that was born in a supernova, provide opportunities to study highly relativistic pulsar winds and their interaction with the surrounding medium. Particularly interesting are PWNe that do not show any sign of the expected surrounding SNR shell and were thought to be born in subenergetic explosions or with unusual progenitors. The detection of a shell around one such PWN suggested that shells are indeed produced but may be faint due to unseen shocked ejecta, a low density environment, and/or a young age that has not yet allowed the shell to brighten and become visible. Here, by using observational X-ray data from modern telescopes with excellent spatial and energy resolution (Chandra and XMM-Newton), we target PWNe that do not have prominent SNR shells, and are known to be in varied environments, to further explore the characteristics of this growing, but poorly explored, class of PWNe. By combining imaging and spectroscopic results, we study the morphology of the PWNe, search for thermal emission from shock-heated material, investigate the energetics of the nebulae, and search for candidates for the neutron stars powering the nebulae. We find that while the faint shell surrounding G21.5–0.9 can be explained as a young PWN evolving in a low density medium, CTB 87 (G74.9+1.2) appears to be in an advanced stage of evolution, and G63.7+1.1 appears to be both in an advanced stage of evolution and in a dense environment. By performing spatially resolved spectroscopy, we have shown how the spectral characteristics vary across the PWNe, and note that more data will place better constraints on possible thermal emission in these remnants. The imaging portion of these studies has revealed intriguing large-scale morphologies for CTB 87 and G63.7+1.1, as well as a torus-jet structure in CTB 87 and neutron star candidates in both CTB 87 and G63.7+1.1. We conclude that both CTB 87 and G63.7+1.1 are likely interacting with the supernova remnant reverse shock, and CTB 87 may be additionally influenced by the motion of its neutron star.

In tunnel excavation, the use of rockbolts has long been a popular means of reinforcement in rock masses to prevent the rock opening from caving in. The idea has evolved from the earliest form of rockbolt made of wood to the more up-to-date form of pre-tensioned or grouted steel rockbolts. A major breakthrough in the design of rockbolt models was made by Aydan (1989). This rockbolt element was modelled in coupled form, with one sub-element representing the steel bolt, and the other sub-element the grout. This representation was necessary to model the complex action in the continuous rock mass near the joint. In elasticity problems, the large displacement formulation of a beam element is derived from the fundamental theory, and the bending phenomenon of a thin rod is analysed by the finite element discretizations of the bar elements and the beam elements. Experiments show that the deformation characteristics of the latter representation resemble a more realistic life behaviour. Based on this finding, this thesis proposes a modification to Aydan's two-dimensional rockbolt element, with the beam elements discretising the steel bolt. The different mechanical responses of a perfectly elastic rockbolt are considered, and the large displacement formulation of the new rockbolt element is derived by combining those of Aydan's rockbolt element and the beam element. The mechanics of the Aydan element and the new rockbolt element are described, and their performances are compared in an identical situation. It is found that in the two two-dimensional examples used in this thesis, the modified element ensures the continuity of curvature of the rockbolt, and in general, can act as support across a discontinuity or joint between rock masses well. In conjunction with the displacement method in the finite element procedures, a conventional iteration solution procedure is first described to solve the nonlinear incremental stiffness equation. However, it is found that this procedure is cumbersome, and requires a large amount of comptutations. Some limited storage quasi-Newton minimization algorithms are considered as an alternative.

This thesis presents a novel approach for a power system to find a practical power flow solution when all the generators in the system have hit their real power output limits, such as some generator units shutting down or load outages. The approach assumes the frequency of the system is unable to be kept at the rated value (usually 60 or 50 Hz) and accordingly, the generator real power outputs are affected by the system frequency deviation. The modification aims to include the system frequency deviation as a new state variable in the power flow so that the power system can be described in a more precise way when the generation limits are hit and the whole system is not operated under the normal condition. A new mathematical formulation for power flow is given by modified the conventional power flow mismatch equation and Jacobian matrix. The Newton – Raphson method is particularly chose to be modified because Newton – Raphson method is most widely used and it is a fast convergent and accurate method. The Jacobian matrix will be augmented by adding a column and a row. Matlab is used as a programming tool to implement the Power Flow for Long Term Frequency Stability (PFLTFS) method for a simple 4-bus system and the IEEE 118-bus system. And PSS/E Dynamic simulation is used to verify the steady state solution from PFLTFS is reasonable. The PSS/E Dynamic Simulation plots are used to analyze the long term frequency response. The PFLTFS method provides a technique for solving an abnormal state system power flow. From the results we can conclude that the PFLTFS method is reasonable for solving power flow of a real power unbalanced system.

Thesis (M.S. )--Duquesne University, 2007. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p. 59-61) and index.

Project (D. Min.)--Trinity Evangelical Divinity School, 1991. / Abstract. Includes bibliographical references (leaves 210-222).

Issued also as thesis, Columbia University, under title: The metaphysics of Sir Isaac Newton.