David Foster Wallace felt that literature was at a historical crossroad, and thatpostmodernism had passed the point which it could still be considered a'revolutionary' cultural phenomenon. He felt that the capitalistic machinery of TVand advertisement had absorbed the postmodernist techniques of pastiche,deconstruction and rejection of a distinction between high and low culturalmodels, to a point where there was no longer a difference between reality and itsown representation. Something that represented a problem for both youngnovelists and readers.This thesis analyses Infinite Jest as a response to this very problem, trying tounderstand in which way Wallace wanted to get over postmodernism, establishinga new kind of literature that highlights the artificiality of reality, by using differenttools than postmodernism. Cross-referencing media and literary studies, my thesisargues that Infinite Jest is a novel that emphasizes the fact that it is a construct. Ishow how the book acknowledges, and gives value to the subjectivity of everyhuman experience, but still stressing the idea that all the data that the reader isreceiving is and will always be heavily mediated information. Therefore, I showhow Wallace uses his characters as if they were human recording devices, creatingin this way a book that is some sort of hybrid between literature and TV.Furthermore, I explain how, by means of narrative devices (such as a disruptiveand incomplete plot, hundreds of endnotes), Wallace wanted to restore thecommunicative function of a text, making himself sure that the reader is invited toactively cooperate in the formation of the novel's meaning, ultimately meeting,and engaging into a dialogue with the author's consciousness in the novel'slanguage, breaking that state of self-consciousness and isolation into which thereader has been condemned by postmodernism and capitalism. Showing that“There's more to life than sitting there simply interfacing”1 David Foster Wallace; Infinite Jest; media studies; Postmodernism; Image-fiction Television; intermediality; transmediality; narratology; heteroglossia. 1 David F. Wallce, Infinite Jest, (Back Bay Books 2016), p. 14.

Die vorliegende Arbeit untersucht die longitudinale Dynamik von Halbleiterlasern anhand eines Modells, in dem ein lineares hyperbolisches System partieller Differentialgleichungen mit gewöhnlichen Differentialgleichungen gekoppelt ist. Zunächst wird mit Hilfe der Theorie stark stetiger Halbgruppen die globale Existenz und Eindeutigkeit von Lösungen für das konkrete System gezeigt. Die anschließende Untersuchung des Langzeitverhaltens der Lösungen erfolgt in zwei Schritten. Zuerst wird ausgenutzt, dass Ladungsträger und optisches Feld sich auf unterschiedlichen Zeitskalen bewegen, um mit singulärer Störungstheorie invariante attrahierende Mannigfaltigkeiten niedriger Dimension zu finden. Der Fluss auf diesen Mannigfaltigkeiten kann näherungsweise durch Moden-Approximationen beschrieben werden. Deren Dimension und konkrete Gestalt ist von der Lage des Spektrums des linearen hyperbolischen Operators abhängig. Die zwei häufigsten Situationen werden dann einer ausführlichen numerischen und analytischen Bifurkationsanalyse unterzogen. Ausgehend von bekannten Resultaten für die Ein-Moden-Approximation, wird die Zwei-Moden-Approximation in dem speziellen Fall untersucht, dass die Phasendifferenz zwischen den beiden optischen Komponenten sehr schnell rotiert, so dass sie sich in erster Ordnung herausmittelt. Mit dem vereinfachten Modell können die Mechanismen verschiedener Phänomene, die bei der numerischen Simulation des kompletten Modells beobachtet wurden, erklärt werden. Darüber hinaus lässt sich die Existenz eines anderen stabilen Regimes voraussagen, das sich im gemittelten Modell als "bursting" darstellt. / We investigate the longitudinal dynamics of semiconductor lasers using a model which couples a linear hyperbolic system of partial differential equations with ordinary differential equations. We prove the global existence and uniqueness of solutions using the theory of strongly continuous semigroups. Subsequently, we analyse the long-time behavior of the solutions in two steps. First, we find attracting invariant manifolds of low dimension benefitting from the fact that the system is singularly perturbed, i. e., the optical and the electronic variables operate on different time-scales. The flow on these manifolds can be approximated by the so-called mode approximations. The dimension of these mode approximations depends on the number of critical eigenvalues of the linear hyperbolic operator. Next, we perform a detailed numerical and analytic bifurcation analysis for the two most common constellations. Starting from known results for the single-mode approximation, we investigate the two-mode approximation in the special case of a rapidly rotating phase difference between the two optical components. In this case, the first-order averaged model unveils the mechanisms for various phenomena observed in simulations of the complete system. Moreover, it predicts the existence of a more complex spatio-temporal behavior. In the scope of the averaged model, this is a bursting regime.

Cette thèse s'inscrit dans le contexte du calcul en temps infini. Par cette désignation, nous faisons référence au temps indicé par des ordinaux, ces derniers possédant de bonnes propriétés pour ``compter''en leur long. En 2000, le modèle des machines de Turing à temps infini fut proposé par Hamkins et Lewis. Ce modèle généralise le processus de calcul des machines de Turing aux étapes de temps représentées par des ordinaux. Dans ce modèle de calcul, les étapes sont indicées par des ordinaux dénombrables, bien que le ruban soit toujours indicé par des entiers naturels. Les entrées du modèle sont donc les suites infinies de lettres. Un certain nombre de comportements nouveaux et étonnants apparaissent avec ces machines. Dans notre thèse, nous nous intéressons à certains de ces comportements.Naturellement, plus les temps de calcul sont longs, plus le modèle est puissant, et plus il devient possible de décider de nouveaux ensembles.À partir d’ordinaux assez grands, de nouvelles propriétés structurelles apparaissent également. L'une d'entre elles est l'existence de brèches dans les temps possibles d'arrêts de programmes. Lorsque ces brèches furent découvertes, de premiers liens entre elles et le caractère admissible des ordinaux qui les commencent furent établis. Notre approche utilise l'algorithmique pour préciser les liens entre les propriétés logiques des ordinaux et les propriétés calculatoires de ces machines à temps infini.Plus précisément, grâce à des des algorithmes spécifiques, nous découvrons et prouvons de nouvelles propriétés sur ces brèches,amenant à une meilleure compréhension de leur structure. Nous montrons notamment que les brèches peuvent être de toutes les tailles (limites) écrivables, qu'il en existe même de taille au moins aussi grande que leur ordinal de début. Jusqu’à la première brèche ayant cette caractéristique, la structure des brèches est assez proche de celle des ordinaux : elles apparaissent en ordre croissant en fonction de leur taille. Nous montrons également que jusqu'à cette brèche spéciale, si les ordinaux admissibles sont exactement les ordinaux débutant les brèches, au-dessus, des ordinaux admissibles peuvent apparaître au milieu de très grandes brèches et la structure des brèches devient désordonnée. / This thesis is centred on the study of infinite time computations. Infinite time here means having a time axis indexed by ordinals — the ordinals are convenient objects along which we can count. The infinite time Turing machine model was introduced by Hamkins and Lewis in 2000. This model generalises the Turing machine computation model to ordinal time. In this model, stages are indexed by (countable) ordinals, even though the tape is indexed by the integers as in the classical model. This model can thus now have infinite strings as input. The main focus of this thesis is the study of some of the new and surprising behaviours that these machines exhibit. Naturally, the longer, i.e., the greater ordinal, the computations run, the more powerful the model is, i.e. it computes/recognizes more sets. If the computations run beyond certain ordinal times, new structural properties also appear. One of these properties is the existence of gaps in the halting times of the machines. When these gaps had been discovered, some first links had been established between these gaps and the admissible character of the ordinals starting them. Our approach uses algorithmics as a mean to emphasize the links between the logical properties of the ordinals involved and the computational properties of the infinite time Turing machines. Moreover, thanks to some specific algorithms, we discover and prove new properties of these gaps, leading to a better understanding of their structure. We show in particular that gaps can have precisely every possible writable ordinal size and that there are gaps whose length is greater or equal than their starting ordinal point. Until the first of such a gap, the gaps appear in increasing sizes. We also show that even if, before this special gap, admissible ordinals only appear at the beginning of gaps, the gaps structure becomes quite disordered beyond that point, with admissible ordinals appearing not only at the beginning but also inside some (huge) gaps.

Neste mestrado propõe-se um estudo sobre o controle automático de sistemas dinâmicos para o problema de coordenação de robôs móveis. Os movimentos coordenados serão realizados em função de um líder e qualquer robô da formação pode assumir a liderança de maneira aleatória. Os robôs trocam informação através de um grafo direcionado (dígrafo) de comunicação, definido a-priori e, movimentos estáveis são gerados através de uma lei de controle descentralizada baseada nas coordenadas dos robôs. Além disso, as equações dinâmicas não lineares dos robôs são descritas na forma de espaço de estado sendo os parâmetros das matrizes dependentes da velocidade angular das rodas. Esta representação, conhecida como Quase Linear a Parâmetros Variantes (Quase-LPV), é utilizada no projeto de controle H \'INFINITO\' não linear para sistemas dinâmicos. Para garantir a estabilidade da formação quando há alternância de líder ou remoção de robôs, foi feito o controle robusto e controle tolerante a falhas para um grupo de robôs móveis com rodas (RMRs). O controle robusto é baseado em controle H \'INFINITO\' não linear via realimentação do estado e controle H \'INFINITO\' não linear via realimentação da saída. O controle tolerante a falhas é baseado em controle H \'INFINITO\' por realimentação da saída de sistemas lineares sujeitos a saltos Markovianos para garantir a estabilidade da formação quando um dos robôs é perdido durante o movimento coordenado. Resultados em simulação são apresentados para os controladores utilizados. / This dissertation proposes a study on the automatic control of dynamic systems to the problem of coordination of mobile robots. The coordinated motions are performed with the robots following a leader, and any robot of the formation can assume the leadership randomly. The robots exchange informations according to a pre-specified communication directed graph (digraph). Stable motions are generated by a decentralized control law based on the robots coordinates. In addition, the nonlinear dynamic equations of the robots are described in state-space form where the parameters matrices depend on the angular velocities of the wheels. This representation, known as Quasi-Linear Parameter Varying (Quasi-LPV), is useful for control designs based on nonlinear H \'INFINITE\' approaches. To ensure the stability formation when there is alternation of leader or one of the robots is removed, we made a robust control and fault tolerant control for a group of wheeled mobile robots (WMRs). The robust approach is based on state feedback nonlinear H \'INFINITE\' control and output feedback nonlinear H \'INFINITE\' control. The fault tolerant approach is based on output feedback H \'INFINITE\' control of Markovian jump linear systems to ensure stability of the formation when one of the robots is lost during the coordinated motion. Results in simulation are presented for the controllers used.

La connaissance implique une prédisposition à la connaissance, c’est-à-dire la possibilité de la relation entre un sujet (connaissant) et un objet (connaissable). D’un autre côté, il y a un état de fait, qui est la connaissance qui a lieu, de fait : la connaissance courante, ordinaire, toujours incomplète, à laquelle l’homme se trouve incessamment avoir accès ou être en train d’avoir accès. La connaissance véritable – pleine et entière – se trouve située à l’extérieur de ce domaine cognitif ordinaire ; extériorité qui implique une indisposition présente à y avoir accès. La connaissance mathématique est du premier ordre – et ce, éminemment, autrement dit, à la fois, en tant que meilleure connaissance possible et en tant que connaissance révélant, le mieux, au travers de son propre inachèvement, l’inachèvement de toute connaissance accessible (dont elle est constitutive ou auxiliaire). Du second ordre, est la connaissance eidétique (connaissance des Formes – eidê, ideai – autrement appelées Idées), qui est la connaissance du réellement réel (ontôs on) (dont l’objet, en sa saisie, ne peut que signer la réelle réalité de la connaissance elle-même). De son côté, la connaissance mathématique induit, en son inachèvement, la connaissance de son principe et élément, qu’est l’unité véritable (c’est-à-dire unique, indivisible et indifférenciée, et donc paradoxalement inconnaissable, en quoi, elle induit, elle-même, l’ordre de la connaissance véritable, qu’est l’ordre eidétique), unité censée trouver, dans l’ordre géométrique, son expression, en tant que mesure et élément communs à tout le mesurable (l’étendu) et, du même coup, à tout le dénombrable ; expression géométrique qui ne manque pas d’être problématique (aporétique), la grandeur demeurant, dans l’absolu, indéfinie, et toute grandeur étant divisible à l’infini, en grandeurs plus petites. Ainsi, se trouve attesté le fait que la disposition cognitive présente (ordinaire) est inéluctablement en deçà d’être disposition à la connaissance véritable, en ce que celle-ci devrait être notamment connaissance du principe, principe que nous pensons trouver désigné, chez Platon, sous l’expression « principe de la ligne », principe dynamique et actif, proprement non mathématique, toujours antérieur à quelque détermination (grandeur) – et, du même coup, à quelque dénombrement – que ce soit. / The knowledge implies a predisposition to the knowledge, that is the possibility of the relation between a (knowing) subject and a (knowable) object. On the other hand, there is an established fact, which is the knowledge which has de facto place : the common, ordinary, always incomplete knowledge, to which the man is continuously to have access or to be having access. The real knowledge – full and whole – is situated outside of this ordinary cognitive domain ; exteriority which implies a present indisposition to have access there. The mathematical knowledge is of the first order – and it is true eminently, in other words, at the same time, as better possible knowledge and as knowledge revealing, best, through its own incompletion, the incompletion of any accessible knowledge (whose it is constitutive or auxiliary). Of the second order, is the eidetic knowledge (knowledge of the Forms – eidê, ideai – otherwise called Ideas), which is the knowledge of the really real (ontôs on) (whose the object, in its grasp, can only sign the real reality of the knowledge itself). From her part, the mathematical knowledge leads, in its incompletion, the knowledge of its principle and element, that is the real unit (that is unique, inseparable and undifferentiated, and thus paradoxically unknowable, in what, it leads, itself, the order of the real knowledge, that is the eidetic order), unit supposed to find, in the geometrical order, its expression, as measure and element common to all the measurable (the extent) and, at the same time, to all the countable ; expression which does not miss to be problematic (aporetic), the size remaining, theoretically, indefinite, and any size being divisible in the infinity, in smaller sizes. So, is attested the fact that the present (ordinary) cognitive disposition is inevitably to be disposition to the real knowledge, in the fact that this one should be in particular knowledge of the principle, the principle which we think of finding indicated, at Plato, under the expression “principle of the line”, dynamic and active, specifically not mathematical principle, always previous to any determination (size) – and, at the same time, to any enumeration – whatsoever.

Made available in DSpace on 2016-04-27T17:26:59Z (GMT). No. of bitstreams: 1 Andrei Venturini Martins.pdf: 1778229 bytes, checksum: 55fe21833ba1001bae979fbe899bfda2 (MD5) Previous issue date: 2011-11-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main goal of this inquiry is to analyze the issue of human condition after the Adamic Fall, according to Blaise Pascal. We have chosen his Lettre that dates from October 17th, 1651, as our main object of analysis. This Lettre is anything but a marginal text within the author s work, representing, on the contrary, the debut of several meditations on themes such as death, compassion, providence, consolation, sacrifice, original sin, self-love, the infinite emptiness, the horror of death before and after the Fall, the love of live before and after the Fall. Our departing hypothesis is that, according to Blaise Pascal, man lives on attempting to deflect the infinite emptiness that dwell in him and fill it somehow, even though only Jesus Christ, as a mediator, is capable of fulfilling the void left by God. To sustain this hypothesis, two major concepts - that of self-love and that of infinite emptiness - present in the foresaid Lettre shall be analyzed throughout the two parts that form this research: A Theory of Original Sin and its Consequences and The Infinite Emptiness of man without God . In Part I, the focus is on the Jansenist spiritual direction of the XVIIth century, and its implications with regards to our object (First chapter). The second chapter focuses on the concepts of Self-Love and Infinite Emptiness, and there we raise the question whether, to Pascal, self-love as detachment from God is the root of all evil and all vices, and whether it is the cause of the infinite emptiness that dwells in man. Apart from Self-Love and Infinite Emptiness, the Lettre also mentions the will to domination and laziness as other consequences of the Adamic Fall. At the end of the first part (Third chapter), we intend to demonstrate the consequences of the Fall as Pascal puts them in the Écrits sur la Grâce: ignorance, concupiscence, guilt and eternal death. Thus, we shall have a more thorough perspective on the consequences of the Fall - something we shall name subjective collage , since we bring the Lettre near to the Écrits sur la Grâce and compose a picture with the consequences of the Fall. In Part II, titled The Infinite Emptiness of man without God , we have elaborated two chapters in order to meditate about human condition based on the concept of infinite emptiness. Chapter IV (the first in Part II) focuses on the relation between infinite emptiness and the Pascalian concept of divertissement; finally, the fifth and last chapter brings the concept of infinite emptiness near to that of Christ as Mediator / O principal objetivo desta pesquisa é analisar a condição humana depois da Queda Adâmica em Blaise Pascal, tendo como objeto central a Lettre de 17 de outubro de 1651. Este texto não pode ser considerado um texto marginal na obra do filósofo francês, mas sim o início de inúmeras reflexões temáticas como a morte, a compaixão, a providência, a consolação, o sacrifício, o pecado original, o amor próprio, o vazio infinito, o horror da morte antes e depois da queda, o amor pela vida antes e depois da queda. A hipótese que norteia este trabalho é que o homem tenta desviar-se e preencher esse vazio infinito causado pela queda através do divertissement, mas só o Cristo Mediador pode ocupar o vazio que Deus deixou. Para demonstrá-la, são investigados dois conceitos capitais na Lettre o Amor Próprio e o Vazio Infinito , ao longo das duas partes que compõem este trabalho: Teoria do pecado original e suas consequências e O Vazio Infinito do homem sem Deus . Na primeira, é investigado o contexto da direção espiritual jansenista no século XVII e seus ecos na Lettre, o que constitui o capítulo I; é trabalhado o conceito de Amor Próprio e Vazio Infinito, no capítulo II, com o intuito de saber se para Pascal o amor próprio desligado de Deus está na raiz de todos os males e de todos os vícios, assim como a causa do vazio infinito no homem sem Deus, pois, além do amor próprio e do vazio infinito, encontra-se na Lettre o desejo de dominação e a preguiça como consequências da queda; e, para finalizar a primeira parte, no capítulo III, são mostradas as consequências da queda expressas nos Écrits sur la Grâce, como a ignorância, a concupiscência, culpa e morte eterna, para que se possa ter, assim, uma visão mais completa, o que foi denominado, neste trabalho, colagem subjetiva , em função da aproximação da Lettre aos Écrits sur la Grâce. Na segunda parte, elaborada em dois capítulos, a fim de refletir a condição humana a partir do conceito de vazio infinito, é estudada, de forma específica, a relação do vazio infinito e o divertissement e, no último capítulo, o mesmo conceito de vazio infinito é aproximado ao Cristo Mediador

Cette thèse est consacrée aux actions des groupes de transformations algébriques sur les variétés affines algébriques. Dans la première partie, on étudie la normalité des adhérences des orbites de tore maximal dans un module rationnel de groupe algébrique simple. La seconde partie porte sur les actions du groupe d'automorphismes d'une variété affine. Nous nous intéressons aux propriétés de transitivité et de transitivité multiple de ces actions sur le lieu lisse de la variété. / This thesis is devoted to the actions of groups of algebraic transformations on affine algebraic varieties. In the first part we study normality of closures of maximal torus orbits in the rational modules of simple algebraic groups. The second part deals with actions of automorphism groups on affine varieties. We study here transitivity and multiple transitivity of such an action on the set of smooth points.

Neste mestrado propõe-se um estudo sobre o controle automático de sistemas dinâmicos para o problema de coordenação de robôs móveis. Os movimentos coordenados serão realizados em função de um líder e qualquer robô da formação pode assumir a liderança de maneira aleatória. Os robôs trocam informação através de um grafo direcionado (dígrafo) de comunicação, definido a-priori e, movimentos estáveis são gerados através de uma lei de controle descentralizada baseada nas coordenadas dos robôs. Além disso, as equações dinâmicas não lineares dos robôs são descritas na forma de espaço de estado sendo os parâmetros das matrizes dependentes da velocidade angular das rodas. Esta representação, conhecida como Quase Linear a Parâmetros Variantes (Quase-LPV), é utilizada no projeto de controle H \'INFINITO\' não linear para sistemas dinâmicos. Para garantir a estabilidade da formação quando há alternância de líder ou remoção de robôs, foi feito o controle robusto e controle tolerante a falhas para um grupo de robôs móveis com rodas (RMRs). O controle robusto é baseado em controle H \'INFINITO\' não linear via realimentação do estado e controle H \'INFINITO\' não linear via realimentação da saída. O controle tolerante a falhas é baseado em controle H \'INFINITO\' por realimentação da saída de sistemas lineares sujeitos a saltos Markovianos para garantir a estabilidade da formação quando um dos robôs é perdido durante o movimento coordenado. Resultados em simulação são apresentados para os controladores utilizados. / This dissertation proposes a study on the automatic control of dynamic systems to the problem of coordination of mobile robots. The coordinated motions are performed with the robots following a leader, and any robot of the formation can assume the leadership randomly. The robots exchange informations according to a pre-specified communication directed graph (digraph). Stable motions are generated by a decentralized control law based on the robots coordinates. In addition, the nonlinear dynamic equations of the robots are described in state-space form where the parameters matrices depend on the angular velocities of the wheels. This representation, known as Quasi-Linear Parameter Varying (Quasi-LPV), is useful for control designs based on nonlinear H \'INFINITE\' approaches. To ensure the stability formation when there is alternation of leader or one of the robots is removed, we made a robust control and fault tolerant control for a group of wheeled mobile robots (WMRs). The robust approach is based on state feedback nonlinear H \'INFINITE\' control and output feedback nonlinear H \'INFINITE\' control. The fault tolerant approach is based on output feedback H \'INFINITE\' control of Markovian jump linear systems to ensure stability of the formation when one of the robots is lost during the coordinated motion. Results in simulation are presented for the controllers used.

Na literatura de controle, os controladores preditivos disponíveis apresentam aplicações limitadas em processos com características integradoras. Uma dessas limitações está relacionada às propriedades estabilizantes que surgem da lei de controle quando o sistema é colocado em malha fechada. O principal objetivo dessa dissertação é desenvolver um algoritmo de controle preditivo, nominalmente estável, baseado num horizonte de predição infinito das saídas do sistema. Para essa finalidade, uma representação existente em variáveis de estado é analisada e estendida para ser capaz de ser aplicável para processos estáveis e integradores, com tempo morto. Dois métodos distintos que garantem a estabilidade de sistemas integradores foram desenvolvidos com um MPC de horizonte infinito. Para o caso de realimentação de estado, a estabilidade nominal do MPC proposto foi provada para os dois métodos e a eficiência dos controladores foi verificada através de exemplos da literatura de controle. Um dos controladores foi também aplicado em um processo de destilação de uma refinaria de petróleo. O algoritmo desenvolvido foi estendido para o caso de realimentação das saídas com a inclusão do filtro de Kalman para a estimativa dos estados do modelo. A aplicação do controlador em um sistema com diferentes tempos mortos entre as variáveis integradoras foi também estudada. / In the control literature, the available predictive controllers show limitations to be applied in processes that have integrating behavior. One of these limitations is related to the stabilizing properties of the resulting control law when the system is in closed loop. The main objective of this work is to develop a nominal stable control algorithm based on infinite prediction of system outputs. For this purpose an existing state space representation is explored and extended in order to be able to be applied to stable and integrating process with dead time. Two distinct methods to assure stability of integrating systems were developed for the infinite horizon MPC. For the case of state feedback, nominal stability of the resulting MPC was proved for the two methods and the efficiency of the controllers was verified through examples of the control literature. One of the controllers was also applied to an industrial distillation process of a petroleum refinery. The developed algorithm was extended to the output feedback operation with the inclusion of a Kalman filter for estimation of the model states. The application of the controller to a system with different dead times between integrating variables was also studied.

We investigate the steady state solutions that can exist for a two dimensional swarm of biological organisms, which have pairwise social interaction forces. The three steady states we investigate using a continuum model are a ribbon migrating swarm, a circular migrating swarm, and a milling swarm. We solve these numerically by reformulating the integral equation that arises from the continuum model as an energy minimization problem. For the ribbon migrating solution, we are able to determine an analytic solution from Carleman's equation which arises after an asymptotic expansion of the social interaction potential. Using this technique we are able to show the existence of a square root singularity that emerges at the boundary of the compactly supported swarm. The analytic solution agrees with the numerical solution for certain parameter values in the social interaction potential. We then demonstrate the existence of solutions for a migrating and milling circular swarm which contain a square root singularity. The milling swarm looks similar to the infinite ribbon, so we are able to use an asymptotic expansion of the potential to obtain an analytic solution in this case as well. The singularities in the density of the swarm suggest that the Morse potential should not be used for modeling biological swarming.