Thesis (Ph. D.)--Senshū Daigaku.

Nesta Tese desenvolvemos várias abordagens "Darbouxianas"para buscar integrais primeiras (elementares e Liouvillianas) de equações diferenciais ordinárias de segunda ordem (2EDOs) racionais. Os algoritmos (semi-algoritmos) que desenvolvemos seguem a linha do trabalho de Prelle e Singer. Basicamente, os métodos que buscam integrais primeiras elementares são uma extensão da técnica desenvolvida por Prelle e Singer para encontrar soluções elementares de equações diferenciais ordinárias de primeira ordem (1EDOs) racionais. O procedimento que lida com 2EDOs racionais que apresentam integrais primeiras Liouvillianas é baseado em uma extensão ao nosso método para encontrar soluções Liouvillianas de 1EDOs racionais. A ideia fundamental por tras do nosso trabalho consiste em que os fatores integrantes para 1-formas polinomiais geradas pela diferenciação de funções elementares e Liouvillianas são formados por certos polinômios denominados polinômios de Darboux. Vamos mostrar como combinar esses polinômios de Darboux para construir fatores integrantes e, de posse deles, determinar integrais primeiras. Vamos ainda discutir algumas implementações computacionais dos semi-algoritmos.

Nous nous intéressons dans ce mémoire à des méthodes de parallélisation par découplage du système dynamique. Plusieurs applications numériques de nos jours conduisent à des systèmes dynamiques de grande taille et nécessitent des méthodes de parallélisation en conséquence pour pouvoir être résolues sur les machines de calcul à plusieurs processeurs. Notre but est de trouver une méthode numérique à la fois consistante et stable pour réduire le temps de la résolution numérique. La première approche consiste à découpler le système dynamique en sous-systèmes contenant des sous-ensembles de variables indépendants et à remplacer les termes de couplage par l’extrapolation polynomiale. Une telle méthode a été introduite sous le nom de schéma C (p, q, j), nous améliorons ce schéma en introduisant la possibilité à utiliser des pas de temps adaptatifs. Cependant, notre étude montre que cette méthode de découplage ne peut satisfaire les propriétés numériques que sous des conditions très strictes et ne peut donc pas s’appliquer aux problèmes raides présentant des couplages forts entre les sous-systèmes. Afin de pouvoir répondre à cette problématique de découplage des systèmes fortement couplés, on introduit le deuxième axe de recherche, dont l’outil principal est la réduction d’ordre du modèle. L’idée est de remplacer le couplage entre les sous-ensembles de variables du système par leurs représentations sous forme réduite. Ces sous-systèmes peuvent être distribués sur une architecture de calcul parallèle. Notre analyse du schéma de découplage résultant nous conduit à définir un critère mathématique pour la mise à jour des bases réduites entre les sous-systèmes. La méthode de réduction d’ordre du modèle utilisée est fondée sur la décomposition orthogonale aux valeurs propres (POD). Cependant, ne disposant pas à priori des données requises pour la construction de la base réduite, nous proposons alors un algorithme de construction incrémentale de la base réduite permettant de représenter le maximum des dynamiques des solutions présentes dans l’intervalle de simulation. Nous avons appliqué la méthode proposée sur les différents systèmes dynamiques tels que l’exemple provenant d’une EDP et celui provenant de l’équation de Navier Stokes. La méthode proposée montre l’avantage de l’utilisation de l’algorithme de découplage basé sur la réduction d’ordre. Les solutions numériques sont obtenues avec une bonne précision comparées à celle obtenue par une méthode de résolution classique tout en restant très performante selon le nombre de sous-systèmes définis. / In this thesis, we are interested in parallelization algorithm for solving dynamical systems. Many industrial applications nowadays lead to large systems of huge number of variables. A such dynamical system requires parallel method in order to be solved on parallel computers. Our goal is to find a robust numerical method satisfying stability and consistency properties and suitable to be implemented in parallel machines. The first method developed in this thesis consists in decoupling dynamical system into independent subsystems and using polynomial extrapolation for coupled terms between subsystems. Such a method is called C(p; q; j).We have extended this numerical scheme to adaptive time steps. However, this method admits poor numerical properties and therefore cannot be applied in solving stiff systems with strong coupling terms.When dealing with systems whose variables are strongly coupled, contrary to the technique of using extrapolation for coupled terms, one may suggest to use reduced order models to replace those terms and solve separately each independent subsystems. Thus, we introduced the second approach consisting in using order reduction technique in decoupling dynamical systems. The order reduction method uses the Proper Orthogonal Decomposition. Therefore, when constructing reduced order models, we do not have all the solutions required for the POD basis, then we developed a technique of updating the POD during the simulation process. This method is applied successfully to solve different examples of dynamical systems : one example of stiff ODE provided from PDE and the other was the ODE system provided from the Nervier-Stokes equations. As a result, we have proposed a robust method of decoupling dynamical system based on reduced order technique. We have obtained good approximations to the reference solution with appropriated precision. Moreover, we obtained a great performance when solving the problem on parallel computers.

L'étude des systèmes aux équations différentielles ordinaires vise à prédire le futur des systèmes considérés. La connaissance de l'évolution dans le temps de toutes les variables d' état du modèle permet de prédire de possibles changements radicaux des variables ou des défaillances, par exemple, un moteur peut exploser, un pont peut s'écrouler, une voiture peut se mettre à consommer plus d'essence. De plus, les systèmes dynamiques peuvent contenir des dérivées spatiales et leur discrétisation peut ajouter un très grand nombre d'équations. La résolution des équations différentielles ordinaires est alors une étape essentielle dans la construction des systèmes physiques en terme de dimensionnement et de faisabilité. Le solveur de tels systèmes EDOs doit être rapide, précis et pertinent.En pratique, il n'est pas possible de trouver une fonction continue qui soit solution exacte du problème EDO. C'est pourquoi, des méthodes numériques sont utilisées afin de donner des solutions discrèes qui approchent la solution continue avec une erreur contrôlable. La gestion précise de ce contrôle est très importante afin d'obtenir une solution pertinente en un temps raisonnable.Cette thèse développe un nouveau solveur qui utilise plusieurs méthodes d'amélioration de la vitesse d'exécution des systèmes EDOs. La première méthode est l'utilisation d'un nouveau schéma numérique. Le but est de minimiser le coût de l'intégration en produisant une erreur qui soit le plus proche possible de la tolérance maximale permise par l'utilisateur du solveur. Une autre méthode pour améliorer la vitesse d'exécution est de paralléliser le solveur EDO en utilisant une architecture multicoeur et multiprocesseur. Enfin, le solveur a été testé avec différentes applications d'OpenModelica. / The study of systems of Ordinary Differential Equations aims at predicting the future of the considered systems. The access to the evolution of all states of a system's model allows us to predict possible drastic shifts of the states or failures, e.g. an engine blowing up, a bridge collapsin, a car consuming more gasoline etc. Solving ordinary differential equations is then an essential step of building industrial physical systems in regard to dimensioning and reliability. The solver of such ODE systems needs to be fast, accurate and relevant.In practice, it is not possible to find a continuous function as the exact solution of the real ODE problem. Consequently numerical methods are used to give discrete solutions which approximates the continuous one with a controllable error. The correct handline of this control is very important to get a relevant solution within an acceptable recovery time. Starting from existing studies of local and global errors, this thesis work goes more deeply and adjusts the time step of the integration time algorithm and solves the problem in a very efficient manner.A new scheme is proposed is this thesis, to minimize the cost of integration. Another method to improve the execution speed is to parallelize the ODE solver by using a multicore and a multiprocessor architecture. Finally, the solver has been tested with different applications from OpenModelica.

In conjunction with raising some questions regarding “genre” in Edo literature, the purpose of this thesis is to introduce a complete annotated translation of Kyōkun hyakumonogatari 教訓百物語 (One Hundred Scary Tales for Moral Instruction) by the Shingaku teacher Murai Yoshikiyo 村井由清 (1752-1813). Published in 1804 and reprinted several times, this text was intended as a guide to self-cultivation and ethical living based on Shingaku 心学, a philosophico-religious movement of great importance in the latter half of the Edo era. The translation is complemented with a transcription into modern script based on publicly available (online) digital images of an 1815 xylographic edition. Considering the work as one example of transgenred literature, in the introduction I explore the intellectual and historical contexts of the work, paying special attention to the contemporary category of textbook called ōraimono 往来物. I also consider for reference a kibyōshi 黄表紙 called Shingaku hayasomegusa 心学早染草, published in 1790 by Santō Kyōden 山東京伝, as another example both of transgenred literature itself and of literary responses to the same socio-intellectual moment, specifically the Edo world in the aftermath of the Kansei reforms (1787-93).

The study is an investigation of the sustainability of agriculture in Nigeria using Rubber as case study. Edo and Abia states were sampled for the study with 300 questionnaires administered in 10 communities among rubber farmers. The study is an investigation of the socio-demographic distribution of the rubber farmers, perception of rubber farmers, and influence of government activities. Sources of information and the data were cumulated for Nigeria as a whole. The data were analyzed using statistical analysis. Findings indicated the distribution of rubber farmers on socio-demographic distribution, sources of funds, and the effects on agricultural sustainability in Nigeria. Farmers’ reaction to government activities and recommendations were stated alongside the challenges encountered by the farmers and were analyzed. concluded that provision of funds, basic infrastructural facilities, government increased participation, restructuring laws and policies relating to agriculture and provision of information on improved agricultural technology are needed for agricultural sustainability in Nigeria.

My project explores the role of affective bonds of a sexual, romantic, and/or mentoring nature between male warriors in the production and maintenance of warrior identity during Japan's Warring States (1467–1603) period. Employing the notion of queer reading as a guiding principle, I examine the traces of intimate bonds between male warriors left behind in poetry, love oaths, personal correspondence, and other documents. I argue that male-male warrior intimacy played a central role, often undervalued by historians due to the conventional disciplinary emphasis on male-female marriage, in the construction of warrior retainer bands and the establishment of warrior alliances. Ranging from the purely hierarchical to the overtly sexual, relationships between warrior youths and their relatively older lords reproduced and reinforced warrior identity, through their violent oathing rituals, recreational activities, and function as a site for cultivating future trusted retainers. A young subordinate could also take advantage of the attention and trust given to him by making demands of his ostensible superior, disrupting the power asymmetries of the lord/retainer bond, or even by openly plotting a rebellion In considering warrior intimacy, the project occasions a reevaluation of the unification process that marks the Warring States period’s central narrative. I contend that the conventional interpretation, which relies on the trope of the Three Unifiers, minimizes the influence of male-male ties on events that effected significant historical change at the macro level, including the circumstances that enabled the Tokugawa clan’s ultimate victory, their vision of the social order, and the form of their sacred authority. I also explore the legacy of these bonds in the Edo period (1603–1868), repurposed as ideals of warrior masculinity and loyal retainership by both samurai attempting to find new purpose in a time of peace and commoners enjoying their newfound wealth and leisure time. Each chapter focuses on an influential warlord and his younger retainer: Ōuchi Yoshitaka (1507–1551) and Sue Harukata (1521–1555); Takeda Shingen (1521–1573) and Gensuke (dates unknown); and Date Masamune (1567–1636) and Tadano Sakujūrō Katsuyoshi (dates unknown), respectively.

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Studien undersöker energisystem i förindustriella Malmö (1700-1845) samt Edo (förindustriella Tokyo 1603-1867). Syftet är att undersöka faktorer som gjorde att två förindustriella städer under en längre tid fungerade utan att stora mängder resurser och energi tillfördes utifrån, förstå vad som förändrade detta samt analysera vad dagens stadsplanerare kan lära av dessa exempel.Undersökningen har gjorts i form av en kvalitativ studie. Studien bortser således ifrån kvantifiering av energidata. Systemperspektiv är en viktig aspekt av studien. Textgenomgång och analys har varit vår huvudmetod för datainsamling. Studien har kommit fram till att för ett hållbar energisystem ärsociala aspekter som invånarnas attityd/mentalitet är en viktig aspekt. Anledningen till att Edo och Malmö kunde upprätthålla sig långt lokalt var att geo-polititiska förutsättning förhindrade de att handla med omvärlden. Industrialiseringen och kapitalismen var huvudfaktor som förändrade lokalenergiförsörjning av båda städerna. Att ständigt utveckla tekniska delen av energisystem till en mer lokala och förnybara är en viktig aspekt men för hållbar stadsplanering är det också viktigt att ta hänsyn till sociala aspekter som invånarnas attityd och kunskaper. I rådande globala ekonomiska systemet är helhetsperspektiv också viktigt för samverkan mellan aktörerna i en stad samt mellan andra städer i världen. / This study examines energy systems in pre-industrial Malmö (1700-1845) and Edo (pre-industrial Tokyo 1603-1867). The objective is to examine pre-industrial facts that made two cities possible to sustain themselves for a long time without consuming a lot of energy and resources, understand the factors that changed it and analyze what today's city planner can learn from these examples. This study takes the form of a qualitative study. It therefore disregards the quantification of energy data. System Pespective is an important aspect of this study. Literature reviews and analysis has been our main method of data collection. Findings of this study indicates that attitude and mentality of inhabitants is an important aspect for a sustainable energy system. The reason why Edo and Malmö could maintain themselves with local energy and resource was due to the geo-political conditions of the cities that prohibited them from interacting with the world. Industrialization and capitalism was a main factor that altered local energy supply of the two cities. To continuously improve technological part of energy system to more local and renewable one is also an essential aspect however for sustainable city planning, inhabitants' attitude and knowledge is also a important part. Under current global economic system, a holistic perspective is also useful for cooperation between actors in a city and other cities in the world.