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Système dynamique et réparti de nommage à indirections multiples pour les communications dans l'InternetTiendrebeogo, Telesphore 24 June 2013 (has links)
Le routage dans Internet est basé sur des tables dites de routage, formées de blocs d’adresses IP. Cependant, la construction et la maintenance de telles tables de routage nécessitent l’utilisation de protocoles complexes qui ne passent pas à l’échelle en termes de mémoire et d’utilisation CPU. De plus, l’expérience montre que le plan d’adressage IP est insuffisant, car la sémantique d’une adresse IP est à la fois un identificateur et un localisateur. Dans nos travaux, nous proposons un système de réseau recouvrant pair-à-pair libre de toute contrainte topologique et utilisant des coordonnées virtuelles prises dans le plan hyperbolique nommé CLOAK (Covering Layer Of Abstract Knowledge en anglais). Les schémas de routages locaux basés sur des coordonnées virtuelles extraites du plan hyperbolique ont suscité un intérêt considérable ces dernières années. Dans cette thèse, nous proposons une nouvelle approche pour saisir le potentiel de la géométrie hyperbolique. L’objectif est de construire un système extensible et fiable pour créer et gérer des réseaux recouvrants dans Internet. Le système est implémenté comme une infrastructure pair-à-pair structuré basé sur les protocoles de la couche transport entre les pairs. Quant à l’organisation des données dans l’espace virtuel, nous employons la réplication pour améliorer la disponibilité et l’accessibilité des objets de l’overlay potentiellement instable. Nous avons implémenté et évalué différentes méthodes de réplication (réplication radiale, réplication circulaire).A l’aide de simulations, nous évaluons notre proposition à travers un certain nombre de métriques et nous montrons que les réseaux recouvrants pair-à-pair basés sur la géométrie hyperbolique ont de bonnes performances par rapport aux autres DHT existantes tout en introduisant flexibilité et robustesse dans les réseaux recouvrants dynamiques. / Internet routing is based on forwarding tables populated by blocks of IP addresses. However, the construction and maintenance of such tables require the use of complex routing protocols that are typically not scalable in terms of memory and CPU usage. Moreover, experience shows that the IP addressing plane is insufficient due to the semantic of an IPaddress being both an identifier and a locator. In this paper, we propose a P2P overlay system of freed topology and using virtual coordinates taken from the hyperbolic plane named CLOAK(Covering Layer Of Abstract Knowledge en anglais). Local knowledge routing schemes based on virtual coordinates taken from the hyperbolic plane have attracted considerable interest in recent years. In this thesis we propose a new approach for seizing the power of the hyperbolic geometry. We aim at building a scalable and reliable system for creating and managing overlay networks over the Internet. The system is implemented as a structured peer-to-peer infrastructure based on the transport layer connections between the peers. Concerning data organisation in the virtual space, we use replication strategy for improve overlay objects disponibilty and accessibility in context potentially unstable. We have implemented and evaluated various replication methods (radial replication, circular replication). Using simulations, we assess our proposal across a certain number of metric and show that overlay Peer-to-Peer network based on the hyperbolic geometry have good performances in comparison with other existent DHT while introducing suppleness and robustness in the dynamic overlay network.
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展延心靈觀 / On the extended mind唐孝儀, Tang, Hsiao Yi Unknown Date (has links)
心靈範圍在哪裡?以往我們討論心靈議題時,不外乎都是將心靈視為存在於體表之內的一種實體、一種器官或是一種功能,例如:靈魂、大腦、又或者是指包含大腦與所有在體表之內的神經系統。但是,Andy Clark與David Chalmers告訴我們在某些情況下,心靈是可以超越體表而存在的,心靈的界限不是我們的體表;這個立場被我們稱為「外在論」或是「展延心靈觀」。對照於Clark與Chalmers的立場,以往將體表視為心靈界限的立場就被統稱為「內在論」。
本篇論文以Clark與Chalmers於1998年發表的文章“The Extended Mind”為主,透過介紹展延心靈觀的發展背景聚焦於展延心靈觀的主要論點,並且根據Frederick Adams與Kenneth Aizawa對展延心靈觀的批評及Clark、Richard Menary等人所提出的回應讓我們對於展延心靈觀有更深入的討論與理解。最後,由Clark與Chalmers所提到的「社會性的展延心靈(socially extended mind)」回到語言與心靈的討論,透過Clark曾多次在文章與著作中提到俄國語言及心理學家Lev Semenovich Vygotsky的語言理論,試圖連結Clark與Chalmers的主動外在論與Putnam和Burge的傳統外在論,並且進一步地思考展延心靈觀發展性。
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Discovery-Oriented Screening of Dynamic Systems: Combinatorial and Synthetic ApplicationsAngelin, Marcus January 2010 (has links)
This thesis is divided into six parts, all centered around the development of dynamic (i.e., reversibly interacting) systems of molecules and their applications in dynamic combinatorial chemistry (DCC) and organic synthesis. Part one offers a general introduction, as well as a more detailed description of DCC, being the central concept of this thesis. Part two explores the potential of the nitroaldol reaction as a tool for constructing dynamic systems, employing benzaldehyde derivatives and nitroalkanes. This reaction is then applied in part three where a dynamic nitroaldol system is resolved by lipase-catalyzed transacylation, selecting two out of 16 components. In part four, reaction and crystallization driven DCC protocols are developed and demonstrated. The discovery of unexpected crystalline properties of certain pyridine β-nitroalcohols is used to resolve a dynamic system and further expanded into asynthetic procedure. Furthermore, a previously unexplored tandem nitroaldol-iminolactone rearrangement reaction between 2-cyanobenzaldehyde and primarynitroalkanes is used for the resolution of dynamic systems. It is also coupled with diastereoselective crystallization to demonstrate the possibility to combine several selection processes. The mechanism of this reaction is investigated and a synthetic protocol is developed for asymmetric synthesis of 3-substituted isoindolinones. Part five continues the exploration of tandem reactions by combining dynamic hemithioacetal or cyanohydrin formation with intramolecular cyclization to synthesize a wide range of 3-functionalized phthalides. Finally, part six deals with the construction of a laboratory experiment to facilitate the introduction of DCC in undergraduate chemistry education. The experiment is based on previous work in our group and features an acetylcholinesterase-catalyzed resolution of a dynamic transthioacylation system. / QC 20100628
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Power Flow Modelling of Dynamic SystemsGeitner, Gert-Helge, Komurgoz, Guven 09 July 2015 (has links) (PDF)
As tools for dynamic system modelling both conventional methods such as transfer function or state space representation and modern power flow based methods are available. The latter methods do not depend on energy domain, are able to preserve physical system structures, visualize power conversion or coupling or split, identify power losses or storage, run on conventional software and emphasize the relevance of energy as basic principle of known physical domains. Nevertheless common control structures as well as analysis and design tools may still be applied. Furthermore the generalization of power flow methods as pseudo-power flow provides with a universal tool for any dynamic modelling. The phenomenon of power flow constitutes an up to date education methodology. Thus the paper summarizes fundamentals of selected power flow oriented modelling methods, presents a Bond Graph block library for teaching power oriented modelling as compact menu-driven freeware, introduces selected examples and discusses special features.
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The Time Course of Negative Priming / Der Zeitverlauf negativen PrimingsDegering, Hendrik 11 December 2009 (has links)
No description available.
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在常微分方程下利用二次逼近法探討人口成長模型問題 / On the Parabola Approximation Method in Ordinary Differential Equation - Modelling Problem on The Population Growth李育佐, Li,Yu Tso Unknown Date (has links)
在人口統計領域中,早期習慣將人口變化視為時間的函數,企圖以Deterministic Function來刻劃,例如:1798年Malthus提出的Malthusian Growth Model ;1825年Gompertz提出的Gompertz Model以及1838年Verhulst主張以Logistic Function描述人口成長。而近年來則是傾向於逐項分析各種因素的隨機性模型,例如:1983年Holford加入世代的APC模型;1992年Lee 和Carter提出的Lee-Carter死亡率模型以及2003年Renshaw與Haberman提出改善Lee-Carter死亡率模型的Reduction Factor模型。
人口變化主要分成自然增加與社會增加,而自然增加是為出生扣掉死亡,社會增加則為移入扣掉移出。首先,本文先不考慮遷移的部分,各別以出生與死亡人口的變化為研究對象,視其變化為一隨時間變動的動態系統,以常微分方程來刻劃。由台灣地區人口統計資料顯示,出生率或死亡率都有逐年下降的趨勢,而且隨著時間而變化加劇的傾向,使得以往使用的模型不易捕捉變化,因此我們提出「二次逼近法」,從出生、死亡人數對時間的變化率與曲度利用數值分析的方式來估計出生與死亡數,進而從中找出在此動態系統背後隱藏的規則。而後再同時考慮其他各種變項,以偏微分方程來刻劃,最後即可建立台灣地區人口變化模型。 / In early population statistics, the population changes were regarded as a function of time so that people tended to
describe the variations by deterministic functions. For instance, Malthus proposed the Malthusian Growth Model in 1798; Gompertz presented Gompertz Model in 1825; Verhulst advocated using logistic function to describe an increase in population. In recent years, people tend to use the stochastic forecast method to analyse every factor term by term. For instance, the Age-Period-Cohort (APC) Model which was proposed by Holford in 1983; Lee and Carter proposed the Lee-Carter Mortality Model in 2003; and Renshaw and Haberman proposed the Reduction Factor Model in 2003 that improve the Lee-Carter Mortality Model.
The population changes equal to nature and social increase, where the nature increase is the difference between birth and death population, and the social increase is the difference between immigrants and emigrants. First, we focus on natural increase rather than social increase. Moreover, we use ordinary differential equation to decribe the variation as a dynamic system over time. From the data obtained from the Ministry of Interior Taiwan, we know that the fertility and mortality has been decreasing, and the change is getting more violent year by year. Under the consideration that previous models are not able to accurately present the changes of birth and death, we proposed "second-order (or parabola) approximation method." From the variation rates and curvatures of birth and death population, we estimated the population size. Furthermore, we want to find the rule in the dynamic system. Later we will consider other factors simultaneously, and describe them by partial differential equation. Finally, the population model is constructed.
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Modèle mathématique d’optimisation non-linéaire du bruit des avions commerciaux en approche sous contrainte énergétique / A non-linear optimization mathematical model of commercial aircraft noise on approach under energy constraintNahayo, Fulgence 04 June 2012 (has links)
Cette thèse traite le développement d'un modèle mathématique d'optimisation acoustique des trajectoires de vol de deux avions commerciaux en approche sous contrainte énergétique, aérodynamique et opérationnelle. C'est un modèle analytique de contrôle optimal non-linéaire et non-convexe régi par un système d'équations différentielles ordinaires issues de la dynamique de vol et des contraintes associées. Notre contribution porte sur la modélisation mathématique des équations, l'optimisation et la programmation algorithmique d'un modèle d'optimisation non-linéaire du bruit de deux avions en approche simultanée. Les points abordés sont le développement mathématique du modèle 3D «exact» de leur dynamique de vol, la modélisation mathématique de la commande optimale de ce système dynamique, l'introduction de la consommation du carburant par les avions comme une équation différentielle avec une fonction consommation spécifique variable en fonction de l'évolution de leur dynamique, la modélisation mathématique instantanée de la fonction objectif représentant le bruit global des deux avions en approche. Sa résolution porte sur la méthode directe de programmation séquentielle quadratique avec régions de confiance sous AMPL et KNITRO. Une méthode indirecte a été appliquée sous le principe de maximum de Pontryagin suivie d’une discrétisation de type Runge-Kutta partition-née symplectique d'ordre 4 afin de démontrer la commutation entre l'approche directe et l'approche indirecte. Les résultats obtenus confirment des trajectoires optimales en descente continue, réduisant le bruit au sol ainsi que la consommation de kérosène de deux avions / This thesis develops an mathematical non-linear optimization model of flight paths of two aircraft in approach minimizing the perceived noise on the ground while energetic constraint is considered. This is an analytical model of non-linear and non-convex optimal control governed by a system of ordinary differential equations resulting from the dynamics of flight and with their associated constraints. Our contribution focuses on the mathematical modeling equations, optimization and algorithmic programming of an acoustic non-linear optimization model of two aircraft simultaneously on approach. The addressed issues are the mathematical development of the «correct» 3D model, their flight dynamics, the mathematical modeling of the optimal control of dynamic system, the consideration of fuel consumption by aircraft as a differential equation with a consumption function specific variable depending on the evolution of their dynamics, the mathematical modeling of the instantaneous objective function representing the overall noise of the two approaching aircraft. Resolution deals with the direct method of sequential quadratic programming with confidence regions while AMPL programming language and KNITRO are considered. An indirect method was applied under the Pontryagin maximum principle, followed by a Runge-Kutta symplectic partitioned discretization to demonstrate the commutation between the direct approach and indirect approach. The expected results confirm optimal trajectories reducing ground noise and fuel consumption of two aircraft
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Modelagem de um processo fermentativo por rede Perceptron multicamadas com atraso de tempo / not availableLuis Fernando Manesco 09 August 1996 (has links)
A utilização de Redes Neurais Artificias para fins de identificação e controle de sistemas dinâmicos têm recebido atenção especial de muitos pesquisadores, principalmente no que se refere a sistemas não lineares. Neste trabalho é apresentado um estudo sobre a utilização de um tipo em particular de Rede Neural Artificial, uma Perceptron Multicamadas com Atraso de Tempo, na estimação de estados da etapa fermentativa do processo de Reichstein para produção de vitamina C. A aplicação de Redes Neurais Artificiais a este processo pode ser justificada pela existência de problemas associados à esta etapa, como variáveis de estado não mensuráveis e com incertezas de medida e não linearidade do processo fermentativo, além da dificuldade em se obter um modelo convencional que contemple todas as fases do processo. É estudado também a eficácia do algoritmo de Levenberg-Marquadt, na aceleração do treinamento da Rede Neural Artificial, além de uma comparação do desempenho de estimação de estados das Redes Neurais Artificiais estudadas com o filtro estendido de Kalman, baseado em um modelo não estruturado do processo fermentativo. A análise do desempenho das Redes Neurais Artificiais estudadas é avaliada em termos de uma figura de mérito baseada no erro médio quadrático sendo feitas considerações quanto ao tipo da função de ativação e o número de unidades da camada oculta. Os dados utilizados para treinamento e avaliação da Redes Neurais Artificiais foram obtidos de um conjunto de ensaios interpolados para o intervalo de amostragem desejado. / ldentification and Control of dynamic systems using Artificial Neural Networks has been widely investigated by many researchers in the last few years, with special attention to the application of these in nonlinear systems. ls this works, a study on the utilization of a particular type of Artificial Neural Networks, a Time Delay Multi Layer Perceptron, in the state estimation of the fermentative phase of the Reichstein process of the C vitamin production. The use of Artificial Neural Networks can be justified by the presence of problems, such as uncertain and unmeasurable state variables and process non-linearity, and by the fact that a conventional model that works on all phases of the fermentative processes is very difficult to obtain. The efficiency of the Levenberg Marquadt algorithm on the acceleration of the training process is also studied. Also, a comparison is performed between the studied Artificial Neural Networks and an extended Kalman filter based on a non-structured model for this fermentative process. The analysis of lhe Artificial Neural Networks is carried out using lhe mean square errors taking into consideration lhe activation function and the number of units presents in the hidden layer. A set of batch experimental runs, interpolated to the desired time interval, is used for training and validating the Artificial Neural Networks.
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Ser sendo: a energia que se conserva ao se transformar - análise de situações da emergência do conceito de energia na aprendizagem em exposição científica e na história / To be by being: the energy that gets conserved by getting transformed - analysis of the situations of the emergence of the physical concept of energy in learning in scientific exhibition and in HistoryMarly Iyo Kamioji 21 September 1995 (has links)
Estudamos o conceito de energia na teoria física a nível histórico e a nível de ensino-aprendizagem, isto é, do ponto de vista de sua criação, representação conceitual, matemática e experimental, na constituição de seu significado na teoria científica e na linguagem comum. Como um exercício preliminar, analisamos alguns dados sobre o ensino de conceitos de física na exposição científica do IFUSP \"Ondas, Campos e Partículas\", de 1989 a 1990, e, em 1991, com o nome de \"Do Caleidoscópio ao Carrossel\", no prédio da Engenharia Mecânica (Escola Politécnica). A exposição apresenta fenômenos das teorias da física nos campos da mecânica, eletricidade e magnetismo, termodinâmica e ótica, fenômenos que implicam ações em escalas macroscópicas e a nível atômico. Descrevemos uma entrevista de 13 minutos com quatro alunos de 1o grau que visitaram a exposição com monitoramento. Durante a situação da entrevista, que chamamos de pedagógica, esses alunos constróem o conceito de energia. Essa entrevista é analisada em termos dos contextos fenomenológico e epistemológico, contidos na exposição, ainda que os monitores que acompanharam a visita não falassem em energia. Descrevemos também uma entrevista com um monitor sobre ensino e aprendizagem. Enfocamos o conceito de \"conhecimento prévio do aluno como requisito para ensino\", e analisamos usando o conceito de zona de desenvolvimento proximal (ZDP) de Vygotsky. Usamos a moldura de Vygotsky (VY 1896/1934) na análise da entrevista com os alunos, que é um exemplo de como considerar a ZDP. Ela não visa avaliação, e nem apenas coleta de dados. Propomos o desenvolvimento de entrevistas pedagógicas para já se constituir uma situação de ensino-aprendizagem, como uma interação desejável, dialógica, onde a ZDP, isto é, a capacidade do aluno \"vir a saber\", seja desenvolvida. A análise da emergência do conceito de energia no caso estudado da entrevista com alunos é feita com a perspectiva de sistemas dinâmicos, dada a natureza complexa dos fenômenos estudados. A História e Filosofia das Teorias Científicas são usadas como ferramenta heurística para identificar correlação na constituição do espaço de significação. Concluíremos que, se os monitores não enfocavam diretamente o conceito de energia e os alunos aprendiam mesmo assim, é porque a exposição é um bom contexto onde a entrevista pedagógica pode ser utilizada como instrumento de ensino, Por fim, falamos da necessidade de um treinamento para monitores, onde sua formação inclua estudos históricos e epistemológicos e uma preparação para suprir a deficiência que detetamos na exposição, isto é, a de não abordar os conceitos na sua forma matematizada. A pesquisa das condições para aprendizagem na Exposição Científica e em Entrevista se desenvolve com instrumentos próprios: um sistema de análise em vídeo foi construído para pesquisar a linguagem usada na interação entre professor e aluno. Objetivamos estabelecer condições propícias para interações dialógicas. Como resultado secundário, foi adquirida certa familiaridade em trabalhar com o vídeo como instrumento para, ao mesmo tempo, mostrar e desenvolver aquisição do conhecimento científico de conceitos de física. / We have studied the concept of energy in Physics in the historical and the Teaching-Learning contexts, i.e., from the point of view of its creation, its mathematical and experimental conceptual representation, of its scientific and ordinary meaning constitution. As a preliminary exercise, we analysed some data about the Physics concepts teaching at the \"Waves, Fields and Particles\" Science Exhibition Center located at that time, in the Engineering Building of the University of São Paulo. The content of the Exhibition was regular demonstrations of phenomena delineated by classical theories of Mechanics, Eletromagnetism, Thermodynamics and some topics in Modern Physics. An interpretation of the exhibition could be in terms of the concept of energy and its transformations, as was shown by an interview with four visiting students described here. During this interview set, which we named pedagogical, these students constructed the concept of energy. This interview is analysed in terms of phenomenological and epistemological implications in the exhibition. A monitor thinking about teaching and learning has also been situated out of an interview. This monitor considers the pupil\'s previous subject matter knowledge as a requirement for teaching. By means of the ZDP (zone of proximal development), we are warned by Vygotsky against the extreme pre-requisites, which can limit the learning. We also make use of Vygotsky\'s concept in the analysis of the interview with students. The interview described in the first part of this work is a ZDP application example. It neither aims evaluation nor just data gathering. It will be developed to be a teaching-learning instrument. We believe this is possible, for it will be an interaction where the ZDP or the pupil\'s ability to \"come to know\" is to be considered. The case study of the emergence of the concept of energy from the interview with pupils is analysed within the framework of dynamic systems given the complex nature of the considered phenomena. The interview was set out in the field of the interactions where information are exchanged between the interviewer and the group and between the peer to peer interaction. The meaning of the concept of energy in Physics was related to the context of the exhibition where the concept was implicitly present. We came to the conclusion that this science exhibition, where the pedagogical interview can be utilized as a tool for teaching, has a good context for learning, once the students showed to have learned even though the docents hadn\'t focused the concept of energy directly. Then we commented about the need of a monitor\'s training, where historical and epistemological studies should be included. This training should also account for the exhibition\'s detected deficiency in approaching the scientific concepts in their mathematical formulation. The research for the emergence of learning in the scientific exhibition center and in interviews is developed by proper tools: a video analysis system is devised to search for the most efficient language in the interaction between teacher and pupil, or in any other teaching-learning situations. Our aim is to establish propitious settings for dialogical interactions in the attempt of dealing with the Vygotsky\'s cognitive \"proximal zone of development\", which is important when we consider the \"process\" of learning a complex concept. As a parallel outcome, we got some familiarity with video recording and analysis as an instrument for both developing and showing the student\'s acquisition of scientific knowledge of physical concepts.
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Číslicová simulace kytarových zesilovačů jako zvukových efektů v reálném čase / Real-time Digital Simulation of Guitar Amplifiers as Audio EffectsMačák, Jaromír January 2012 (has links)
Práce se zabývá číslicovou simulací kytarových zesilovačů, jakož to nelineárních analogových hudebních efektů, v reálném čase. Hlavním cílem práce je návrh algoritmů, které by umožnily simulaci složitých systémů v reálném čase. Tyto algoritmy jsou prevážně založeny na automatizované DK-metodě a aproximaci nelineárních funkcí. Kvalita navržených algoritmů je stanovana pomocí poslechových testů.
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