Dissertations / Theses on the topic 'Space time matter induction'

In this thesis we focus on Gaussian quantum metrology in the phase-space formalism and its applications in quantum sensing and the estimation of space-time parameters. We derive new formulae for the optimal estimation of multiple parameters encoded into Gaussian states. We discuss the discontinuous behavior of the figure of merit -- the quantum Fisher information. Using derived expressions we devise a practical method of finding optimal probe states for the estimation of Gaussian channels and we illustrate this method on several examples. We show that the temperature of a probe state affects the estimation generically and always appears in the form of four multiplicative factors. We also discuss how well squeezed thermal states perform in the estimation of space-time parameters. Finally we study how the estimation precision changes when two parties exchanging a quantum state with the encoded parameter do not share a reference frame. We show that using a quantum reference frame could counter this effect.

Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.<br>Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Environmental Sciences and Engineering, School of Public Health." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.

I provide an interpretation of Hume’s argument in Treatise 1.2 Of the Ideas of Space and Time that finite extensions are only finitely divisible (hereafter Hume’s Finite Divisibility Argument). My most general claim is that Hume intends his Finite Divisibility Argument to be a demonstration in the Early Modern sense as involving the comparison and linking of ideas based upon their intrinsic contents. It is a demonstration of relations among ideas, meant to reveal the meaningfulness or absurdity of a given supposition, and to distinguish possible states of affairs from impossible ones. It is not an argument ending in an inference to an actual matter of fact. Taking the demonstrative nature of his Finite Divisibility Argument fully into account radically alters the way we understand it. Supported by Hume’s own account of demonstration, and reinforced by relevant Early Modern texts, I follow to its logical consequences, the simple premise that the Finite Divisibility Argument is intended to be a demonstration. Clear, abstract ideas in Early Modern demonstrations represent possible objects. By contrast, suppositions that are demonstrated to be contradictory have no clear ideas annexed to them and therefore cannot represent possible objects—their ‘objects,’ instead, are “impossible and contradictory.” Employing his Conceivability Principle, Hume argues that there is a clear idea of a finite extension containing a finite number of parts and therefore, finitely divisible extensions are possible. In contrast, the supposition of an infinitely divisible finite extension is “absurd” and “contradictory” and stands for no clear idea. Consequently, Hume deems this supposition “impossible and contradictory,” that is, without meaning and therefore, descriptive of no possible object. This interpretation allays concerns found in the recent literature and helps us better understand what drives Hume’s otherwise perplexing argument in the often neglected or belittled T 1.2.

This research explores the lives and learning of a group of Grade R children and their human and non-human collaborators, (myself included) paying particular attention to the agency of the material environment. The learning spaces of a preschool and its neighbouring park emerge as key players in the lively thinking-with that is sparked off by our engagements with each other: people, other creatures, plants, spaces, things, energies, pasts, presents and futures. The spaces cannot be separated from their relationships with time and matter (of which we are a part), nor from the stories, habits and patterns of our engagement with them. All of these connected things, material and discursive, work in the research as lively assemblages or apparatuses that change and are changed by ongoing and unanticipated events. Photographs and video clips produce new ideas about and with the data created through the project and rather than reflecting reality, these visual forms diffract with time and space to offer the researcher and the participants new and different sensory, conceptual, affective and temporal experiences. These differences make a difference to the thinking that emerges. Relationships of accountability and belonging are recognized as central concepts in the learning with the park and the preschool. Paying attention to the choices we can make about taking care of our human and nonhuman relations or 'kin’ invites new thoughts about what it means to learn together in an inner-city preschool. Learning together requires a posthuman ethics that pays attention to what matters in the entanglements of learning and the becoming response-able to one another.

This thesis studies the symmetries and phenomenologies of the massive vector fields of indefinite spin with both scalar and spin-one degrees of freedom and Elko. The investigation is conducted by using and extending the quantum field theory formalism developed by Wigner and Weinberg. In particular, we explore the possibility that the W± and Z bosons have an additional scalar degree of freedom and show that Elko is a fermionic dark matter candidate. We show that the massive vector fields of indefinite spin are consistent with Poincaré symmetry and have physically desirable properties that are absent for their pure spin-one counterpart. Using the new vector fields, the decay of the W± and Z bosons to leptons at tree-level are in agreement with the Standard Model (SM) predictions. For higher order scattering amplitudes, the theory has better convergent behaviour than the intermediate vector boson model and the Fermi theory. Elko has the unusual property that it satisfies the Klein-Gordon but not the Dirac equation and has mass dimension one instead of three-half. We show that the Elko fields are local only along a preferred axis and that they violate Lorentz symmetry. Motivated by the results obtained by Ahluwalia and Horvath that the Elko spin-sums are covariant under very special relativity (VSR) transformations, we derive the VSR particle states and quantum fields. We show that the VSR particles can only interact with the SM particles through gravity and massive scalar particles thus making them and hence Elko dark matter candidates.

In high power induction motor drives, the switching frequency of the inverter is quite low due to the high losses in the power devices. Real-time PWM strategies, which result in reduced harmonic distortion under low switching frequencies and have maximum possible DC bus utilisation, are developed for such drives in the present work. The space vector approach is taken up for the generation of synchronised PWM waveforms with 3-Phase Symmetry, Half Wave Symmetry and Quarter Wave Symmetry, required for high-power drives. Rules for synchronisation and the waveform symmetries are brought out. These rules are applied to the conventional and modified forms of space vector modulation, leading to the synchronised conventional space vector strategy and the Basic Bus Clamping Strategy-I, respectively. Further, four new synchronised, bus-clamping PWM strategies, namely Asymmetric Zero-Changing Strategy, Boundary Sampling Strategy-I, Basic Bus Clamping Strategy-II and Boundary Sampling Strategy-II, are proposed. These strategies exploit the flexibilities offered by the space vector approach like double-switching of a phase within a subcycle, clamping of two phases within a subcycle etc. It is shown that the PWM waveforms generated by these strategies cannot be generated by comparing suitable 3-phase modulating waves with a triangular carrier wave. A modified two-zone approach to overmodulation is proposed. This is applied to the six synchronised PWM strategies, dealt with in the present work, to extend the operation of these strategies upto the six-step mode. Linearity is ensured between the magnitude of the reference and the fundamental voltage generated in the whole range of modulation upto the six-step mode. This is verified experimentally. A suitable combination of these strategies leads to a significant reduction in the harmonic distortion of the drive at medium and high speed ranges over the conventional space vector strategy. This reduction in harmonic distortion is demonstrated, theoretically as well as experimentally, on a constant V/F drive of base frequency 50Hz for three values of maximum switching frequency of the inverter, namely 450Hz, 350Hz and 250Hz. Based on the notion of stator flux ripple, analytical closed-form expressions are derived for the harmonic distortion due to the different PWM strategies. The values of harmonic distortion, computed based on these analytical expressions, compare well with those calculated based on Fourier analysis and those measured experimentally.

In high power induction motor drives, the switching frequency of the inverter is quite low due to the high losses in the power devices. Real-time PWM strategies, which result in reduced harmonic distortion under low switching frequencies and have maximum possible DC bus utilisation, are developed for such drives in the present work. The space vector approach is taken up for the generation of synchronised PWM waveforms with 3-Phase Symmetry, Half Wave Symmetry and Quarter Wave Symmetry, required for high-power drives. Rules for synchronisation and the waveform symmetries are brought out. These rules are applied to the conventional and modified forms of space vector modulation, leading to the synchronised conventional space vector strategy and the Basic Bus Clamping Strategy-I, respectively. Further, four new synchronised, bus-clamping PWM strategies, namely Asymmetric Zero-Changing Strategy, Boundary Sampling Strategy-I, Basic Bus Clamping Strategy-II and Boundary Sampling Strategy-II, are proposed. These strategies exploit the flexibilities offered by the space vector approach like double-switching of a phase within a subcycle, clamping of two phases within a subcycle etc. It is shown that the PWM waveforms generated by these strategies cannot be generated by comparing suitable 3-phase modulating waves with a triangular carrier wave. A modified two-zone approach to overmodulation is proposed. This is applied to the six synchronised PWM strategies, dealt with in the present work, to extend the operation of these strategies upto the six-step mode. Linearity is ensured between the magnitude of the reference and the fundamental voltage generated in the whole range of modulation upto the six-step mode. This is verified experimentally. A suitable combination of these strategies leads to a significant reduction in the harmonic distortion of the drive at medium and high speed ranges over the conventional space vector strategy. This reduction in harmonic distortion is demonstrated, theoretically as well as experimentally, on a constant V/F drive of base frequency 50Hz for three values of maximum switching frequency of the inverter, namely 450Hz, 350Hz and 250Hz. Based on the notion of stator flux ripple, analytical closed-form expressions are derived for the harmonic distortion due to the different PWM strategies. The values of harmonic distortion, computed based on these analytical expressions, compare well with those calculated based on Fourier analysis and those measured experimentally.

This thesis analyzes the direction of time problem in the framework of philosophy of science. The radiation arrow, Newtonian arrow, thermodynamic arrow and quantum mechanical arrow have been studied in detail. The importance of the structure of space-time concerning direction of time is emphasized.

In this thesis, we study various aspects of physics in higher-dimensional manifolds involving a single extra dimension. After giving some historical perspective on the motivation for studying higher-dimensional theories of physics, we describe classical tests for a non-compact extra dimension utilizing test particles and pointlike gyroscopes. We then turn our attention to the problem of embedding any given <i>n</i>-dimensional spacetime within an (<i>n</i>+1)-dimensional manifold, paying special attention to how any structure from the extra dimension modifies the standard <i>n</i>-dimensional Einstein equations. Using results derived from this investigation and the formalism derived for test particles and gyroscopes, we systematically introduce three specific higher-dimensional models and classify their properties; including the Space-Time-Matter and two types of braneworld models. The remainder of the thesis concentrates on specific higher-dimensional cosmological models drawn from the above mentioned scenarios; including an analysis of the embedding of Friedmann-Lemaitre-Robertson-Walker submanifolds in 5-dimensional Minkowski and topological Schwarzschild spaces, and an investigation of the dynamics of a <i>d</i>-brane that takes the form of a thin shell encircling a (<i>d</i>+2)-dimensional topological black hole in anti-deSitter space. The latter is derived from a finite-dimensional action principle, which allows us to consider the canonical quantization of the model and the solutions of the resulting Wheeler-DeWitt equation.

fato bastante conhecido que os conceitos de tempo e de espaço desempenham papel central na filosofia de Leibniz; a forte oposição que ela fez aos mesmos conceitos utilizados na filosofia newtoniana é prova disso. Nesse sentido, pretendemos oferecer uma série de considerações que partem desses conceitos em sua relação com um outro conceito fundamental da filosofia leibniziana: o conceito de substância individual. Acreditamos que uma compreensão adequada das relações mais fundamentais entre esses conceitos pode lançar luz sobre o que Leibniz entendia ser necessário ter como ponto de partida para sua Dinâmica e para sua Psicologia, como elas se relacionam com sua Metafísica e como isso tem conseqüências para o que ele pensava quanto à Ética e Religião. A partir destas considerações acreditamos poder constituir parte importante das saídas, seja do labirinto do contínuo, seja do labirinto da necessidade ao modo como Leibniz as pensou e como isso pode contribuir para compreendermos questões que ainda são da ordem do dia quanto aos fundamentos da Ciência Contemporânea.<br>It is a fact sufficiently known that the space and the time concepts play central role in the Leibniz philosophy; the strong opposition that it has made to the same concepts used in the Newtonian philosophy is a prove of that. In this sense, we intend to offer a series of considerations that leave from these concepts in its relation with one another fundamental concept of the leibnizian philosophy: the individual substance concept. We believe that an adequate understanding of the most fundamentals relations between these concepts can light up on what Leibniz understood to be necessary to have as starting point for its Dynamics and its Psychology, as they relate to its Metaphysics and as it has consequences for what he used to think about Ethics and Religion. From these considerations we believe to be able to constitute important part of the exit either of the labyrinth of the continuous either of the labyrinth of the necessity according to the way as them were thought by Leibniz and as this can contribute to understand questions that are still of the order of the day referring to the bases of the Contemporaneous Science.

Toute œuvre littéraire s’inscrit dans un mouvement de pensée singulier apte à lui donner une forme propre : un espace. La forme unitaire ou morcelée que constitue un ensemble romanesque est significative des intentions et des intuitions de l’auteur. En cherchant à déterminer les limites de l’espace romanesque célinien, nous tentons de comprendre les motivations du geste littéraire et, à travers les romans de Louis-Ferdinand Céline, de conceptualiser ce qui pourrait devenir un outil d’analyse critique : « l’espace romanesque »<br>All literary works are given a particular form – space – by the movement of their author’s mind. The unified or divided form built by the novelistic body of work bears witness to the intentions and intuitions of the author. By seeking to identify the limits of the celinian novelistic space, we aim at understanding what motivates the act of writing and, through a reading of the novels of Louis-Ferdinand Céline, try to conceptualize what could come to be used as a tool of critical analysis: the “novelistic space”

This thesis is a comparison of the philosophical systems of Zen Buddhism, which is an Eastern Philosophy, with Ludwig Wittgenstein&rsquo<br>s philosophical studies, who is an extraordinary name of the Western Philosophy in the 20th century. The history and sources of Zen Buddhism were given with its adoption in the use of language and arts. Besides, this study exemplifies the philosophy of Zen Buddhism with the examples from the life story of Wittgenstein. The thesis is written with a full awareness of the sensitivity of comparing different systems which always embody counterexamples and speculations. This is the reason why speculative ideas and resources were deliberately ignored. The aim is to contribute the cultural life of Turkey by taking such a subject to the academic milieu. Moreover, Turkey is the passage of the East and the West both geographically and culturally. There are resemblances between Zen and Wittgenstein by means of method and the useof language. Furthermore, it was given the names of the books that Wittgenstein read and the philosophers who influenced Wittgenstein. The parallels between Zen and Wittgenstein are justified.

Parental monitoring of settings is not always relevant for the prevention of adolescent crime because adolescents with strong personal moral rules and the ability to exercise self control are unlikely to offend even when they are unsupervised and know that their parents have little knowledge about their activities. Parental monitoring, commonly operationalised as parental supervision or parental knowledge, is often shown to have a negative relationship with crime involvement. However, research often ignores both the mechanism by which these relationships occur and the conditions under which they might (and might not) be found. This thesis uses specialist Space-Time Budget data (from the Peterborough Adolescent and Young Adult Development Study) to allow the comparison of adolescent crime rates in settings characterised by the of convergence of i) the physical presence or absence of parents and other guardians, ii) the psychological presence or absence of parents (represented by adolescent-perceived generalised parental knowledge of the circumstances of unsupervised activity) and iii) personal crime propensity (moral rules and ability to exercise self control). The conclusion derived from the results is that the physical presence of parents and other guardians in settings reduces the rate of adolescent crime committed in those settings; and the psychological presence of parents reduces the criminogenic impact of unsupervised time. Crucially however, these effects of parental monitoring are almost irrelevant for adolescents with a lower personal crime propensity, who are not likely to offend in settings irrespective of the physical or psychological absence of parents and other guardians. These findings provide support for person-environment interactions inherent in the causal model of Situational Action Theory, and provide a novel addition to evidence that could be used in future to inform policy-relevant recommendations concerning parenting behaviour and adolescent offending. Although this thesis provides new evidence about the relationship between parental monitoring and crime, the bulk of its contribution is relevant to a much wider audience. It contributes to the debate on approaches to the study of crime and crime prevention, adds clarity to key concepts and develops theoretical arguments in the field of parental monitoring and crime, develops a novel application of Situational Action Theory, extends theoretical and methodological discussions surrounding situational analysis, applies novel data and analytical methods to the study of the psychological and physical presence of guardians, generates and situates unique findings about the situational role of aspects of parental monitoring and crime, and makes some policy recommendations and suggestions about the nature and direction of future research.

85f.<br>Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-05T12:34:32Z No. of bitstreams: 1 willyamssantospt1seg.pdf: 723840 bytes, checksum: 45798b7ea614cf59bf68cfccfce67ea2 (MD5)<br>Approved for entry into archive by Lêda Costa(lmrcosta@ufba.br) on 2013-04-18T12:37:19Z (GMT) No. of bitstreams: 1 willyamssantospt1seg.pdf: 723840 bytes, checksum: 45798b7ea614cf59bf68cfccfce67ea2 (MD5)<br>Made available in DSpace on 2013-04-18T12:37:19Z (GMT). No. of bitstreams: 1 willyamssantospt1seg.pdf: 723840 bytes, checksum: 45798b7ea614cf59bf68cfccfce67ea2 (MD5) Previous issue date: 2006<br>A presente dissertação, desenvolvida no Mestrado em Artes Visuais da Escola de Belas Artes da Universidade Federal da Bahia, na linha de Processos Criativos, aborda aspectos relacionados as apropriações de imagens grafitadas, encontradas nos muros da cidade de Salvador, como também os meios técnicos e operacionais para a sua remoção na qual são nomeadas de peles grafitadas. Em seguida são selecionadas e posteriormente deslocadas para o espaço interno da galeria, ressignificando-as como documentos visuais, que vão comentando e ampliando notícias, pautando os dias, disseminando uma teia polissêmica de significados. A investigação das imagens grafitadas no espaço público ocupa-se a dar procedimentos em gerar uma poética, baseando-se em aspectos plásticos e conceituais à partir de princípios formativos para a construção da obra, sustentados principalmente por conceitos de pensadores como Gaston Bachelard, Henri Bérgson, Merleau-Ponty e Didi-Huberman.<br>Salvador

The aim of this study is to make an inquiry on the nature and the development of dualities in Bergson&rsquo<br>s philosophy. Since the nature of each duality differs from the others and the dualistic pattern inherent in Bergsonian philosophy is subject to change, we base our study on a chronological structure in order to comprehend better how this pattern changes. We claim that such an inquiry will yield relevant outcomes with regard to ontological and epistemological evolution of Bergson&rsquo<br>s thought. To state more precisely, we are of the idea that the modification in the dualistic pattern in Bergson&rsquo<br>s ontology is reflected in a parallel manner in his epistemology. The fundamental question that shows us the way to follow in our study is whether the elements of the dualities (whether they be ontological or epistemological) are reconciled by Bergson or they are left as absolutely distinct elements. At the end of the inquiry regarding that question, which we believe can be taken as an inspiring point in developing new approaches especially to epistemological problems, our conviction is that Bergson points out to a meeting point.

Dissertation aims to clearly document the whole unique wide range of issues relating to the architectural space, including its historical development. Thesis should remind the fundamental questions we have to ask working with space and basic ways to access this phenomenon and to draw attention to their importance for the formulation of the overall architectural concept. The fundamental geometric concepts should be clarified on the theoretical basis, which are currently used for the expression of diverse concepts, or geometry, which are themselves fundamental concept of architectural design. They are concepts that significantly extend the range of expression of architecture.

Tudo inicia com o verbete de um dicionário não convencional. A revista Documents, na qual se publicava o Dictionnaire Critique, era editada pelo escritor francês Georges Bataille quando ele escreveu sobre o informe: um termo que \"serve para desclassificar\"; um vocábulo que não existe para dar significado a determinadas coisas, mas para instigar \"tarefas\"; uma noção antagônica a toda \"sobrecasaca matemática\"; uma disrupção ao academicismo \"que geralmente demanda que cada coisa tenha sua forma\". Esta dissertação fundamenta-se na acepção batailliana, destrinchando nuances, revisitando múltiplas leituras feitas a posteriori, buscando compreender o verbete em meio a todo conjunto do Dicionário Crítico, e, por fim, aceitando a diversidade e as contradições da rede de relações que Bataille instituía. Alicerçado nesse verbete acerca do informe, estabeleço uma operação crítica de observação do mundo, a qual irradia uma série de questões para além daquelas enfrentadas à época pelo grupo surrealista da Documents. Informes, no plural, apresenta um campo de diálogo entre trabalhos artísticos, projetos arquitetônicos, obras literárias. A crise do ideal de forma não é unívoca. O informe lança uma ilimitada multiplicidade de questões; nesta dissertação, apresentam-se algumas delas em um labirinto que põe em contato o Partially Buried Woodshed de Robert Smithson, o Tent Pile do Formlessfinder, a Endless House de Frederick Kiesler, o apartamento de A Espuma dos Dias, o Gutter Corner Splash e as espirais de Richard Serra, a crise da arte como ciência europeia por Edmund Husserl, os Sacchi de Alberto Burri, o vão livre do Masp e o pré-artesanato nordestino pela ótica de Lina Bo Bardi, a Torsione de Giovanni Anselmo somada a tantos outros trabalhos da dita Arte Povera, o Monumento a Bataille de Thomas Hirschhorn, o Merzbau de Kurt Schwitters, o Vortex do Raumlabor, o empilhar de telhas de Wang Shu, a entropia que se ausenta em O ateliê vermelho de Henri Matisse, o estúdio de Rémy Zaugg projetado pelo Herzog & de Meuron, a Mesa de Nelson Felix, o Fun Palace de Cedric Price, o Granby Four Streets do Assemble, os inacabados prisioneiros de Michelangelo. Essa polifonia consubstancia-se nos dezenove ensaios que se seguem. Tal como uma entrada de dicionário, cada texto é autossuficiente; entretanto, suas questões ricocheteiam ao longo da dissertação. Inspirado no Dictionnaire Critique e no livro Formless: A User\'s Guide, de Yve-Alain Bois e Rosalind Krauss, faço um emaranhado de heterogêneas rela- ções a partir de diferentes autores, artistas, arquitetos. Não há uma mesma unidade nem métrica para os ensaios: as estruturas textuais são diversas, os tamanhos são distintos, e sua leitura também não se faz exigente em ordem sequencial.. Há uma metalinguagem entre o informe e o (não)formato deste Informes. O que se intenta é o enfrentamento às convenções, ao status quo, ao senso comum. Uma busca deste mestrando para não ver o mundo como conjunto de formas, as quais obrigatoriamente devamos nos enquadrar. Afinal, já dizia Bataille, \"o universo é algo como uma aranha ou um escarro\".<br>Everything begins with an entry of an unconventional dictionary. The magazine Documents, in which the Dictionnaire Critique was published, was edited by the French writer Georges Bataille when he wrote about the formless: a term that \"serves to bring things down\"; a word that does not exist to give meaning to certain things, but to instigate \"tasks\"; an antagonistic notion to any \"mathematical frock coat\"; a disruption to academicism that \"generally requiring that each thing have its form\". This dissertation is based on the bataillian sense of the formless, unraveling nuances, revisiting multiple readings made a posteriori, seeking to understand the entry in the midst of all set the Critical Dictionary, and, finally, accepting diversity and contradictions of the network of relationships that Bataille instituted. From this entry on the formless, I establish a critical operation for observing the world, which radiates a number of issues beyond those that the Surrealist group faced at the time of Documents magazine. Formlesses, in plural, present a field of dialogue between artistic works, architectural projects, literary writings. The crisis of the ideal of form is not univocal. Formless launches unlimited and multiple questions, which, on this dissertation, present themselves in a labyrinth that put in contact the Partially Buried Woodshed by Robert Smithson, the Tent Pile by Formlessfinder, the Endless House by Frederick Kiesler, the apartment of L\'Écume des Jours, the Gutter Corner Splash and the spirals by Richard Serra, the crisis of art as a European science by Edmund Husserl, the Sacchi by Alberto Burri, the great span of Masp and the northeastern pre-crafts from the perspective of Lina Bo Bardi, the Torsione by Giovanni Anselmo together with many other of the Arte Povera, the Monument to Bataille by Thomas Hirschhorn, the Merzbau by Kurt Schwitters, the Vortex by Raumlabor, the stacking of tiles of Wang Shu, the absence of entropy in The Red Studio by Henri Matisse, the atelier of Rémy Zaugg designed by Herzog & de Meuron, the Mesa by Nelson Felix, the Fun Palace by Cedric Price, the Granby Four Streets by Assemble, the unfinished prisoners of Michelangelo. This polyphony is embodied on the following nineteen essays. Like a dictionary entry, each text is self-sufficient; however, their issues ricochet throughout the dissertation. Inspired by the Dictionnaire Critique and the book Formless: A User\'s Guide, of Yve-Alain Bois and Rosalind Krauss, I make a tangle of heterogeneous relationships from different authors, artists, architects. There is neither unity nor metric on the essays: the textual structures are diverse, their sizes are different, and it is not necessary to read them in a sequential order. There is a metalanguage between the formless and the (non)format of this Formlesses. What I attempt is to confront the conventions, the status quo, the common sense. A search of this graduate student for not to see the world as a set of forms, in which we must necessarily fit in. After all, as Bataille had already said, \"the universe is something like a spider or spit\".

Ce travail porte sur la modélisation et le dimensionnement des moteurs à aimants permanents et asynchrones destinés à la propulsion marine par POD. Un état de l’art est présenté, où les différentes topologies de moteurs pour ce type d’application y sont abordées. La Machine à aimants permanents et la machine asynchrone on été retenue pour notre application. Dans le cas de la machine à aimants permanents, une analyse par éléments finis est effectuée pour dimensionner la machine à aimants permanents et minimiser les principaux harmoniques de la FÉM. Un modèle éléments finis 2D en magnétostatique couplé à un modèle circuit est développé pour la prédiction des couples pulsatoires dues aux harmoniques du convertisseur. En ce qui concerne la machine asynchrone, Pour tenir compte des harmoniques d’espace et évaluer leurs pertes, un modèle électromagnétique utilisant la résolution par éléments finis 2D en magnétodynamique couplé à un modèle circuit est développé. Par ailleurs, un autre modèle basé sur le principe de couplage éléments finis- circuit électrique est développé pour tenir compte des harmoniques de temps du variateur, ce modèle permet d’évaluer à la fois les pertes dues aux harmoniques de temps, mais aussi des couples pulsatoires. Dans la phase de validation et vérification des différents calculs, nous avons utilisé l’outil Flux2D de calcul par éléments finis qui tient compte de la rotation du rotor (pas à pas dans le temps) et effectué certaines mesures (cas de la machine à aimants permanents). Les résultats des calculs obtenus par les modèles développés concordent avec ceux obtenus par la méthode temporelle (pas à pas dans le temps) et les quelques mesures dont nous disposons<br>This work concerns the modeling and the design of the permanent magnets and asynchronous motors intended for POD ship propulsion. A state of the art is presented, where various topologies of motors designed for this application are approached there. The permanent magnet motor and the induction motor have been chosen for the application. For the permanent magnets motor, a finite element analysis is adopted to design and minimize the main harmonics leading to a quasi sinusoidal back EMF. A finite element model coupled to an electrical circuit allows to predict both current and torque waveforms including time harmonics knowing the voltage waveform of the inverter. The induction motor is designed in such a way to have minimum losses and pulsating torque. For this purpose, a 2D complex finite element method coupled to an electrical circuit is developed. In addition, another 2D finite element-electrical circuit model is proposed to evaluate time harmonics losses and to reconstitute the current and torque waveforms. This model allows to predict the pulsating torques. The validation and verification step is done by using a time stepping finite element software Flux2D and some available measurements (for the permanent magnets motor). The comparison of the calculations obtained by the different methods and software, as well as the available measurements is satisfactory

Le but principal du présent travail est ainsi de réaliser une expérience de mélange par la turbulence, dans laquelle il est possible de déterminer et de quantifier les temps de cohérence des différentes échelles spatiales des fluctuations du champ de vitesse et du champ de concentration qu'il transporte et mélange. La turbulence est ici voisine de la situation idéale statistiquement homogène et isotrope, et la configuration est conçue pour qu'il en soit de même pour le champ de concentration. La turbulence est créée par une grille placée perpendiculairement à un écoulement uniforme à l'extérieur des couches limites qui se développent le long des parois de la veine d'essais à section carrée constante. L'écoulement de la présente étude est un écoulement d'eau, dans lequel le champ de concentration est celui d'une solution de Rhodamine B injectée au niveau de la grille à travers des injecteurs équi-répartis le long des barreaux de celle-ci. Ce choix, dicté par la technique de mesure du champ de concentration par Fluorescence Induite par Laser, permet en outre de mesurer le champ de vitesse par une autre technique optique, elle aussi non-intrusive. Pour se rapprocher le plus de la théorie d'un mélange idéal statistiquement homogène et isotrope sans vitesse moyenne, on considère dans l'expérience, conformément à l'hypothèse de Taylor, que toutes les échelles associées à chacun de ces champs, sont convectés à la vitesse moyenne U de l'écoulement, et l'on suit une "boîte de turbulence" qui se déplace à cette vitesse le long de la veine. Par suite déterminer l'état de la turbulence en un point donné de cette boite à l'instant t et à l'instant t'=t+dt, revient à l'étudier dans l'expérience à t à l'abscisse x de la veine d'essai, et à t' à l'abscisse x+dx , avec dx=Udt, où se trouve le point de la boîte aux deux instants successifs. Les résultats expérimentaux concernant les échelles pour lesquelles l'isotropie statistique est satisfaite, permettent alors de vérifier une phénoménologie de l'évolution de la cohérence temporelle des diverses échelles spatiales du champ des fluctuations de concentration fondée sur les idées de Comte-Bellot et Corrsin. Cette expérience, est en outre l'occasion de donner des résultats sur les densités de probabilité de diverses propriétés statistiques des champs de fluctuation de vitesse.

This work explores the multidimensional, ambiguous and temporal characteristics of tonality. The approach relies on interfacing pitch-spaces with time vs. time-scale descriptions. In this combined representation, the spatial and temporal hierarchies of tonality are evidenced simultaneously and in relation to each other. A visual exploration method is proposed for the analysis of tonal context in music works, using a simple model of tonal induction. The method is extended for the analysis of music based on tonal systems beyond the major-minor paradigm. Two perceptual studies are approached from this descriptive framework. The first study evidences the impact of time-scale in a simple mode of tonal induction, and analyses the mathematical artefacts introduced by evaluations in scaled spaces. In the second study, a model of contextual instability is proposed and discussed in relation to the modelling of tonal tension. The analysis and representation methods are then generalised, through a set-class theoretical domain.<br>Esta tesis analiza la naturaleza ambigua, multidimensional y temporal de la tonalidad. El método propuesto parte de la conexión entre espacios tonales y descripciones en tiempo y escala temporal. Esta representación conjunta pone de manifiesto la relación entre las jerarquías espaciales y temporales de la tonalidad. Utilizando un modelo simple de inducción tonal, se propone un método de exploración visual del contexto tonal en obras musicales. Dos estudios perceptuales son abordados desde el entorno descriptivo propuesto. En el primer estudio, se pone en evidencia el impacto de la escala temporal como parámetro de un modelo simple de inducción tonal, y se analizan los artificios matemáticos introducidos por evaluaciones en espacios escalados dimensionalmente. En el segundo estudio se propone un modelo de inestabilidad contextual, y se analiza en relación al modelado de la tensión tonal. El método de análisis se generaliza, a través de una categorización contextual en set-classes.

Les plus brefs flashs de lumière qui puissent être produits en laboratoire actuellement ont des durées de quelques dizaines d'attosecondes (1 as = 10-18 s), et ne peuvent être créés que dans le domaine extrême-ultraviolet (XUV). Le développement de composants optiques capables de contrôler et de mettre en forme ce rayonnement attoseconde est crucial pour permettre à ces impulsions de se généraliser. Cette thèse porte donc sur l'étude et la réalisation de tels composants.Les impulsions attosecondes ont la particularité de comporter une dérivée de fréquence intrinsèque au processus utilisé pour leur génération. Cela a pour effet d'augmenter leur durée. Nous avons donc développé des miroirs multicouches capables d'induire une dérive de fréquence opposée sur les impulsions s'y réfléchissant, permettant ainsi de les compresser. En caractérisant les impulsions attosecondes réfléchies par ces miroirs, nous avons pour la première fois observé une telle compression des impulsions attosecondes. Nous avons également développé des miroirs multicouches théoriquement capables de compresser des impulsions sous la barre symbolique des 50 as, soit en dessous du record actuel de durée d'une impulsion lumineuse.La mesure de ces impulsions requiert leur focalisation dans un spectromètre. Or les miroirs focalisants généralement utilisés peuvent très rapidement introduire des aberrations géométriques. A l'aide de simulations numériques et d'une étude analytique, nous avons montré que ces aberrations pouvaient très fortement déformer la structure spatio-temporelle des impulsions attosecondes, provoquant une augmentation de leur durée. Enfin, nous avons montré que ces effets n'étaient pas pris en compte par les techniques actuelles de caractérisation d'impulsions attosecondes, cela pouvant amener à mesurer une impulsion attoseconde plus courte qu'elle ne l'est en réalité.

Ce travail porte sur la modélisation et le dimensionnement des moteurs à aimants permanents et asynchrones destinés à la propulsion marine par POD. Un état de l’art est présenté, où les différentes topologies de moteurs pour ce type d’application y sont abordées. La Machine à aimants permanents et la machine asynchrone on été retenue pour notre application. Dans le cas de la machine à aimants permanents, une analyse par éléments finis est effectuée pour dimensionner la machine à aimants permanents et minimiser les principaux harmoniques de la FÉM. Un modèle éléments finis 2D en magnétostatique couplé à un modèle circuit est développé pour la prédiction des couples pulsatoires dues aux harmoniques du convertisseur. En ce qui concerne la machine asynchrone, Pour tenir compte des harmoniques d’espace et évaluer leurs pertes, un modèle électromagnétique utilisant la résolution par éléments finis 2D en magnétodynamique couplé à un modèle circuit est développé. Par ailleurs, un autre modèle basé sur le principe de couplage éléments finis- circuit électrique est développé pour tenir compte des harmoniques de temps du variateur, ce modèle permet d’évaluer à la fois les pertes dues aux harmoniques de temps, mais aussi des couples pulsatoires. Dans la phase de validation et vérification des différents calculs, nous avons utilisé l’outil Flux2D de calcul par éléments finis qui tient compte de la rotation du rotor (pas à pas dans le temps) et effectué certaines mesures (cas de la machine à aimants permanents). Les résultats des calculs obtenus par les modèles développés concordent avec ceux obtenus par la méthode temporelle (pas à pas dans le temps) et les quelques mesures dont nous disposons<br>This work concerns the modeling and the design of the permanent magnets and asynchronous motors intended for POD ship propulsion. A state of the art is presented, where various topologies of motors designed for this application are approached there. The permanent magnet motor and the induction motor have been chosen for the application. For the permanent magnets motor, a finite element analysis is adopted to design and minimize the main harmonics leading to a quasi sinusoidal back EMF. A finite element model coupled to an electrical circuit allows to predict both current and torque waveforms including time harmonics knowing the voltage waveform of the inverter. The induction motor is designed in such a way to have minimum losses and pulsating torque. For this purpose, a 2D complex finite element method coupled to an electrical circuit is developed. In addition, another 2D finite element-electrical circuit model is proposed to evaluate time harmonics losses and to reconstitute the current and torque waveforms. This model allows to predict the pulsating torques. The validation and verification step is done by using a time stepping finite element software Flux2D and some available measurements (for the permanent magnets motor). The comparison of the calculations obtained by the different methods and software, as well as the available measurements is satisfactory

Zhang, Yaojun =<br>"November 2009."<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2010.<br>Includes bibliographical references (p. 109-111).<br>Abstracts in English and Chinese.<br>Zhang, Yaojun =<br>Abstract --- p.i<br>Acknowledgement --- p.iv<br>Chapter 1 --- Introduction --- p.1<br>Chapter 2 --- Quasi-Normal Modes of Neutron Stars --- p.6<br>Chapter 2.1 --- Equilibrium State of a Neutron Star --- p.6<br>Chapter 2.2 --- Fluid Displacement and Metric Perturbation --- p.8<br>Chapter 2.3 --- Axial Oscillations of Neutron Stars --- p.9<br>Chapter 2.3.1 --- Wave Equation inside the Star --- p.9<br>Chapter 2.3.2 --- Wave Equation outside the Star --- p.10<br>Chapter 2.3.3 --- Location of Quasi-normal Modes --- p.10<br>Chapter 2.4 --- Polar Oscillations of Neutron Stars - LD Formalism --- p.12<br>Chapter 2.4.1 --- Equations inside the Star --- p.12<br>Chapter 2.4.2 --- Equations outside the Star --- p.14<br>Chapter 2.4.3 --- Location of Quasi-normal Modes --- p.16<br>Chapter 2.5 --- Polar Oscillations of Neutron Stars - AAKS Formalism --- p.16<br>Chapter 2.5.1 --- Equations inside the Star --- p.16<br>Chapter 2.5.2 --- Equations outside the Star --- p.19<br>Chapter 2.5.3 --- Location of Quasi-normal Modes --- p.19<br>Chapter 3 --- Decoupling of Spacetime Oscillations and Fluid Motion --- p.21<br>Chapter 3.1 --- Motivation of Decoupling --- p.21<br>Chapter 3.2 --- Expressing F in terms of S and H --- p.21<br>Chapter 3.2.1 --- Inside the Star --- p.22<br>Chapter 3.2.2 --- Outside the Star --- p.25<br>Chapter 3.3 --- Constraint-free AAKS Formalism --- p.25<br>Chapter 3.3.1 --- Equations inside the Star --- p.25<br>Chapter 3.3.2 --- Equations outside the Star --- p.27<br>Chapter 3.4 --- Cowling Approximation for Polar p-Mode --- p.29<br>Chapter 3.4.1 --- Independent Fluid Motion --- p.29<br>Chapter 3.4.2 --- Location of Polar p-Modes --- p.30<br>Chapter 3.4.3 --- Numerical Results and Discussion --- p.31<br>Chapter 3.5 --- Inverse-Cowling approximation for ω-Mode --- p.33<br>Chapter 3.5.1 --- Independent Spacetime Oscillations --- p.33<br>Chapter 3.5.2 --- Location of ω-Modes --- p.34<br>Chapter 3.5.3 --- Numerical Results and Discussion --- p.34<br>Chapter 4 --- Interplay between Matter and Spacetime --- p.37<br>Chapter 4.1 --- Physical Insight --- p.37<br>Chapter 4.2 --- Sturm-Liouville Eigenvalue Problem --- p.39<br>Chapter 4.3 --- Energy of the Fluid --- p.40<br>Chapter 4.4 --- Spacetime Oscillation Driven by Fluid Motion --- p.45<br>Chapter 4.5 --- Damped Oscillation Caused by Radiation of Gravitational Wave --- p.46<br>Chapter 4.6 --- Calculation of δωn in a Perturbative Way --- p.48<br>Chapter 4.7 --- Numerical Results and Discussion --- p.49<br>Chapter 5 --- Asymptotic Behavior of Spacetime Modes --- p.61<br>Chapter 5.1 --- Motivation --- p.61<br>Chapter 5.2 --- Asymptotic Behavior of Axial ω-modes for One-Layered Stars --- p.62<br>Chapter 5.2.1 --- "Asymptotic Form of g(r*,ω)" --- p.63<br>Chapter 5.2.2 --- "Asymptotic Form of f(r*, ω)" --- p.67<br>Chapter 5.2.3 --- Asymptotic Behavior of Axial Quasi-Normal Modes --- p.69<br>Chapter 5.3 --- Asymptotic Behavior of Polar ω-modes for One-Layered Stars --- p.71<br>Chapter 5.3.1 --- High-Frequency Approximation --- p.71<br>Chapter 5.3.2 --- Asymptotic Behavior of Polar Quasi-Normal Modes --- p.73<br>Chapter 5.4 --- Relationship between Axial and Polar ω-Modes --- p.74<br>Chapter 5.4.1 --- Application 1:ω-Modes of Quark Stars --- p.75<br>Chapter 5.4.2 --- Application 2:ω-Modes of Polytropic Stars --- p.80<br>Chapter 5.4.3 --- Application 3: The Influence of Surface Discontinuities --- p.89<br>Chapter 5.4.4 --- Application 4:ω-Modes of Realistic Neutron Stars --- p.92<br>Chapter 6 --- Conclusion and Outlook --- p.99<br>Chapter A --- From Einstein Equation to LD Formalism --- p.101<br>Chapter A.l --- The Linearized Perturbation Equations --- p.101<br>Chapter A.1.1 --- The Perturbation of the Einstein Tensor --- p.102<br>Chapter A.1.2 --- The Perturbation of the Energy-momentum Tensor --- p.103<br>Chapter A.1.3 --- The Perturbed Einstein Equations --- p.104<br>Chapter A.2 --- Some Symbolic Operation Results --- p.105<br>Chapter A.3 --- Simplifications --- p.106

Climate change and introduced species are among the top five threats to freshwater systems face. Tropical regions are considered to be especially sensitive to the effects of climate change, while island systems are more susceptible to species introductions. Climate-driven changes in rainfall are predicted to decrease streamflow and increase flash flooding in many tropical streams. In addition, guppies (Poecilia reticulata), an invasive fish, have been introduced to many tropical freshwater ecosystems, either intentionally for mosquito population control, or accidentally because of the aquarium trade. This dissertation examines the effects of climate-driven change in rainfall and introduced guppies on stream structure (resource and invertebrate biomass and composition) and function (nutrient recycling) in Trinidad and Hawaii. In the first data chapter we used a time series to examine how nutrient recycling of guppies changes in the first 6 years after introduction to a new habitat and to examine drivers of these changes. We found that when guppy populations establish in a new environment, they show considerable variation in nutrient recycling through time. This resulted from changes in guppy density in the first two years of introductions, and changes in individual excretion in subsequent stages. In the following chapter we utilized a rainfall gradient that mimics forecasted, climate-driven changes in precipitation and resulting changes in streamflow to examine the effects of climate change on stream food resources and macroinvertebrates. We found that the drying of streams across the gradient was associated with a decrease in resource quality and a 35-fold decline in macroinvertebrate biomass. Invertebrate composition also switched to taxa with faster turnover rates. In the third data chapter we used this same space-for-time substitution approach to determine if climate-driven changes in stream structure also affected stream function. We showed that population nutrient recycling rates declined at the drier end of our rainfall gradient as a result of drops in population densities. We also found that under the current climate scenario, community excretion supplied up to 70% of the nutrient demand, which was ten-fold lower with projected climate changes in streamflow. Lastly, since freshwater ecosystems often face multiple human impacts, including climate change and invasive species, we wanted to understand how climate-driven changes in flow might alter the impact of introduced guppies on stream ecosystems. We selected several streams with guppies and several without guppies along the Hawaii rainfall gradient to examine if the effect of guppies changed with differences in streamflow. We found that the two stressors had synergistic effects on macroinvertebrate biomass and nutrient recycling rates. We concluded that climate change appeared to enhance effects of guppies, through direct and indirect effects. Overall, this dissertation shows that both climate change and species invasion can affect stream ecosystems at multiple levels of organization. This dissertation demonstrates that the effects of anthropogenic stressors are not static through time, and emphasizes the need and utility of using several methodological approaches when measuring the temporal effects of stressors. We also underline the significance of assessing multiple stressor interactions, as more than one stressor often impacts ecosystems.<br>Graduate<br>2019-09-01

The Philosophers such as ibn-Sina had maintained that time and space were co-eternal with Allah, emanating by necessity from His Attributes, and not being the results of a deliberate act of creation. This must be the case, for otherwise nothing would have been present to induce Him to create the world after a period of non-existence. Al-Ghazali's refutation of this is that Allah had decreed in pre-eternity that the world would materialize at a future, predetermined date, selecting an instance for its birth from a myriad like-instances by exercising His Free Will and manifesting therewith a cause with a delayed effect. The Philosophers' explanation of local phenomena as resulting from the perpetual motion of the spheres is flawed, since perpetual celestial motions would result in perpetual, not transient phenomena. Time, the measure of motion, does not extend beyond the physical realm. Time, and hence motion, is finite.<br>Religious Studies and Arabic<br>M.A. (Ancient Languages & Cultures)