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An evidential answer for the capacitated vehicle routing problem with uncertain demands / Une réponse évidentielle pour le problème de tournée de véhicules avec contrainte de capacité et demandes incertainesHelal, Nathalie 20 December 2017 (has links)
Le problème de tournées de véhicules avec contrainte de capacité est un problème important en optimisation combinatoire. L'objectif du problème est de déterminer l'ensemble des routes, nécessaire pour servir les demandes déterministes des clients ayant un cout minimal, tout en respectant la capacité limite des véhicules. Cependant, dans de nombreuses applications réelles, nous sommes confrontés à des incertitudes sur les demandes des clients. La plupart des travaux qui ont traité ce problème ont supposé que les demandes des clients étaient des variables aléatoires. Nous nous proposons dans cette thèse de représenter l'incertitude sur les demandes des clients dans le cadre de la théorie de l'évidence - un formalisme alternatif pour modéliser les incertitudes. Pour résoudre le problème d'optimisation qui résulte, nous généralisons les approches de modélisation classiques en programmation stochastique. Précisément, nous proposons deux modèles pour ce problème. Le premier modèle, est une extension de l'approche chance-constrained programming, qui impose des bornes minimales pour la croyance et la plausibilité que la somme des demandes sur chaque route respecte la capacité des véhicules. Le deuxième modèle étend l'approche stochastic programming with recourse: l'incertitude sur les recours (actions correctives) possibles sur chaque route est représentée par une fonction de croyance et le coût d'une route est alors son coût classique (sans recours) additionné du pire coût espéré des recours. Certaines propriétés de ces deux modèles sont étudiées. Un algorithme de recuit simulé est adapté pour résoudre les deux modèles et est testé expérimentalement. / The capacitated vehicle routing problem is an important combinatorial optimisation problem. Its objective is to find a set of routes of minimum cost, such that a fleet of vehicles initially located at a depot service the deterministic demands of a set of customers, while respecting capacity limits of the vehicles. Still, in many real-life applications, we are faced with uncertainty on customer demands. Most of the research papers that handled this situation, assumed that customer demands are random variables. In this thesis, we propose to represent uncertainty on customer demands using evidence theory - an alternative uncertainty theory. To tackle the resulting optimisation problem, we extend classical stochastic programming modelling approaches. Specifically, we propose two models for this problem. The first model is an extension of the chance-constrained programming approach, which imposes certain minimum bounds on the belief and plausibility that the sum of the demands on each route respects the vehicle capacity. The second model extends the stochastic programming with recourse approach: it represents by a belief function for each route the uncertainty on its recourses (corrective actions) and defines the cost of a route as its classical cost (without recourse) plus the worst expected cost of its recourses. Some properties of these two models are studied. A simulated annealing algorithm is adapted to solve both models and is experimentally tested.
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Anti-paternalism and Public Health PolicyGrill, Kalle January 2009 (has links)
This thesis is an attempt to constructively interpret and critically evaluate the liberal doctrine that we may not limit a person’s liberty for her own good, and to discuss its implications and alternatives in some concrete areas of public health policy. The thesis starts theoretical and goes ever more practical. The first paper is devoted to positive interpretation of anti-paternalism with special focus on the reason component – personal good. A novel generic definition of paternalism is proposed, intended to capture, in a generous fashion, the object of traditional liberal resistance to paternalism – the invocation of personal good reasons for limiting of or interfering with a person’s liberty. In the second paper, the normative aspect of this resistance is given a somewhat technical interpretation in terms of invalidation of reasons – the blocking of reasons from influencing the moral status of actions according to their strength. It is then argued that normative anti-paternalism so understood is unreasonable, on three grounds: 1) Since the doctrine only applies to sufficiently voluntary action, voluntariness determines validity of reasons, which is unwarranted and leads to wrong answers to moral questions. 2) Since voluntariness comes in degrees, a threshold must be set where personal good reasons are invalidated, leading to peculiar jumps in the justifiability of actions. 3) Anti-paternalism imposes an untenable and unhelpful distinction between the value of respecting choices that are sufficiently voluntary and choices that are not. The third paper adds to this critique the fourth argument that none of the action types typically proposed to specify the action component of paternalism is such that performing an action of that type out of benevolence is essentially morally problematic. The fourth paper ignores the critique in the second and third papers and proposes, in an anti-paternalistic spirit, a series of rules for the justification of option-restricting policies aimed at groups where some members consent to the policy and some do not. Such policies present the liberal with a dilemma where the value of not restricting people’s options without their consent conflicts with the value of allowing people to shape their lives according to their own wishes. The fifth paper applies the understanding of anti-paternalism developed in the earlier papers to product safety regulation, as an example of a public health policy area. The sixth paper explores in more detail a specific public health policy, namely that of mandatory alcohol interlocks in all cars, proposed by the former Swedish government and supported by the Swedish National Road Administration. The policy is evaluated for cost-effectiveness, for possible diffusion of individual responsibility, and for paternalistic treatment of drivers. The seventh paper argues for a liberal policy in the area of dissemination of information about uncertain threats to public health. The argument against paternalism is based on common sense consequentialist considerations, avoiding any appeal to the normative anti-paternalism rejected earlier in the thesis. / QC 20100714
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Prognose des Langzeitverhaltens von Textilbeton-Tragwerken mit rekurrenten neuronalen NetzenFreitag, Steffen, Graf, Wolfgang, Kaliske, Michael 03 June 2009 (has links) (PDF)
Zur Prognose des Langzeitverhaltens textilbetonverstärkter Tragwerke wird ein modellfreies Vorgehen auf Basis rekurrenter neuronaler Netze vorgestellt. Das Vorgehen ermöglicht die Prognose zeitveränderlicher Strukturantworten unter Berücksichtigung der gesamten Belastungsgeschichte. Mit unscharfen Größen aus Messungen an Versuchstragwerken werden rekurrente neuronale Netze trainiert. Anschließend ist die unscharfe Prognose des Tragverhaltens möglich.
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Anti-paternalismGrill, Kalle January 2006 (has links)
<p>This is a thesis about anti-paternalism – the liberal doctrine that we may not interfere with a person’s liberty for her own good. Empirical circumstances and moral values may certainly give us reason to avoid benevolent interference. Anti-paternalism as a normative doctrine should, however, be rejected.</p><p><em>Essay I</em> concerns the definitions of paternalism and anti-paternalism. It is argued that only a definition of paternalism in terms of compound reason-actions can accommodate its special moral properties. Definitions in terms of actions, common in the literature, cannot. It is argued, furthermore, that in specifying the reason-actions in further detail, the notion of what is self-regarding, as opposed to other-regarding, is irrelevant, contrary to received opinion.</p><p><em>Essay II </em>starts out with the definition of paternalism defended in essay I and claims that however this very general definition is specified, anti-paternalism is unreasonable and should be rejected. Anti-paternalism is the position that certain reasons – referring one way or the other to the good of a person, give no valid normative support to certain actions – some kind of interferences with the same person. Since the reasons in question are normally quite legitimate and important reasons for action, a convincing argument for anti-paternalism must explain why they are invalid in cases of interference. A closer look at the reasons and actions in question provides no basis for such an explanation.</p><p><em>Essay III</em> considers a concrete case of benevolent interference – the withholding of information concerning uncertain threats to public health in the public’s best interest. Such a policy has been suggested in relation to the European Commission’s proposed new system for the<em> R</em>egistration, <em>E</em>valuation, and <em>A</em>uthorisation of <em>Ch</em>emicals (REACH). Information about uncertain threats to health from chemicals would allegedly spread anxiety and depression and thus do more harm than good. The avoidance of negative health effects is accepted as a legitimate and good reason for withholding of information, thus respecting the conclusion of essay II, that anti-paternalism should be rejected. Other reasons, however, tip the balance in favour of making the information available. These reasons include the net effects on knowledge, psychological effects, effects on private decisions and effects on political decisions.</p>
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Waiting for Certainty: young people, mobile phones and uncertain scienceChristensen, Clare Karen January 2007 (has links)
This dissertation is an empirical study of the scientific literacy of 28 young adults (aged 18-26 years) in the context of their decision making about the health risks of mobile phones. The issue of possible health effects is one of a number of socioscientific issues now confronting adults in the 'knowledge/risk' society where scientific knowledge plays an increasingly significant role in people's lives. The focus of interest is the young people's responses to the uncertain science of 'science in the making' (Latour, 1987) and their positioning of this scientific knowledge in their risk assessments. The study is based on an interactive model of the public understanding of science and applies a critical realist and moderate social constructionist methodology. Data construction included focus groups and semi-structured individual interviews. The stimulus for discussion in the focus groups was a recent television news report presenting contradictory scientific research findings about whether mobile phones pose significant health risks. In the individual interviews understanding of the nature of science and risk judgments were explored. Data analysis involved a coding of the discourse in terms of themes and issues and interpretation of these in terms of the theoretical framework of the thesis. A major finding was that these young people interpreted the uncertainty of the scientific knowledge mainly in social terms and with limited understanding of the role of theory in interpreting data. They talked spontaneously of risk but did not draw on scientific knowledge or risk estimates in their judgment about mobile phone safety. Findings have important implications for science education and suggest a broadened conception of scientific literacy which includes critical dimensions and risk literacy. It is argued that this functional scientific literacy is essential for effective citizenship in contemporary society.
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Controle chaveado e chaveado suave de sistemas não lineares incertos via modelos fuzzy T-S / Switched and smooth switched control of uncertain nonlinear systems via T-S fuzzy modelsAlves, Uiliam Nelson Lendzion Tomaz 14 December 2017 (has links)
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Previous issue date: 2017-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O controle chaveado pode ser eficientemente utilizado no controle de sistemas fuzzy TakagiSugeno (T-S) incertos, que possuam funções de pertinência incertas e modelos locais conhecidos. Como estes sistemas fuzzy podem representar exatamente uma classe de sistemas não lineares incertos em uma região do espaço de estados, é interessante utilizá-los para descrever sistemas não lineares, usando no projeto do controlador o modelo fuzzy que descreve exatamente o sistema não linear. Porém, como a representação através de combinação convexa obtida é válida apenas em uma região do espaço de estados, garantias de que o estado do sistema permaneça nessa região devem ser obtidas. Neste trabalho são propostas condições que garantem a estabilização local, com a especificação da taxa decaimento, de uma classe de sistemas não lineares contínuos no tempo, incertos e com saturação no atuador, utilizando o controle chaveado. Os projetos dos controladores são realizados com base no modelo fuzzy T-S que representa exatamente o sistema não linear e os procedimentos de projeto fornecem uma região na qual as condições iniciais devam estar, tal que, o sistema não linear seja exatamente descrito pelo modelo fuzzy T-S incerto durante toda a trajetória de estado do sistema e ainda que esta trajetória permaneça dentro de uma região de operação previamente especificada. Em geral, o controle chaveado não possui restrição na frequência de chaveamento dos ganhos, o que pode levar ao chattering, que se manifesta pelo chaveamento em frequência infinitamente rápida dos ganhos de realimentação. Visando a eliminação do chattering no controle chaveado, propõe-se uma nova técnica de suavização do controle chaveado, o controle chaveado suave. Esta nova lei de controle pode ser utilizada nas mesmas condições do controle chaveado e é baseada no conceito do mínimo suave, definido neste trabalho. Além disso, são propostos procedimentos de projeto que consideram distúrbios para ambas as leis de controle chaveada e chaveada suave. Ademais, neste trabalho também se apresenta uma implementação da lei de controle chaveada em um sistema Ball Balancer fabricado pela Quanser. / The switched control can be efficiently used for controlling uncertain Takagi-Sugeno (T-S) fuzzy systems, which have uncertain membership functions and known local models. Because these fuzzy systems can exactly represent a class of uncertain nonlinear systems in a given operation region in the state space, it is interesting to use them to describe nonlinear systems, performing the controller design based on a T-S fuzzy model that exactly describes the nonlinear system. However, the perfect representation of the uncertain nonlinear system by the T-S fuzzy model as a convex combination is only valid in the operation region. Therefore, it is necessary to assure conditions such that the state of the system remains in that region. This work proposes conditions to ensure the local stabilization, with decay rate, of a class of uncertain continuoustime nonlinear systems with saturation on the actuator, using a switched control. The designs of the controllers are performed based on the T-S fuzzy model which exactly describes the nonlinear system and the design procedures provide a region in which the initial conditions must be such that the nonlinear system is exactly described by the uncertain T-S fuzzy model along the whole state trajectory of the system and this trajectory remains in a specified operation region. Usually, the switched control has no bound on the frequency of the feedback gains switching, and this can lead to chattering, which is manifested by infinitely fast frequency of the feedback gains switching. In order to avoid the chattering in the switched control, this work proposes a new technique to smooth the switched control, the smooth switched control. This new control law can be used under the same conditions as the switched control and it is based on the concept of smooth minimum, which is defined in this work. In addition, design procedures considering disturbances for both switched and smooth switched control laws are proposed. Furthermore, in this work it is also presented an implementation of the proposed switched control law in a Ball Balancer system manufactured by Quanser.
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Projeto de controle robusto para sistemas chaveados via LMIs /Tello, Ivan Francisco Yupanqui January 2017 (has links)
Orientador: Rodrigo Cardim / Resumo: Neste trabalho são apresentados uma série de resultados relacionados com as técnicas de controle para sistemas lineares chaveados incertos que asseguram índices de desempenho e custos garantidos no projeto. Inicialmente a técnica abordada para este estudo consiste na utilização das desigualdades de Lyapunov-Metzler e as propriedades dos sistemas Estritamente Reais Positivos (ERP). São abordados os sistemas Lyapunov-Metzler-ERP (LMERP), que permitem o desenvolvimento de um método de projeto de estabilização para sistemas que apresentam comutação e incertezas no modelo, usando para isto a realimentação do vetor de estado. A análise de estabilidade é descrita por meio de Desigualdades Matriciais Lineares (em inglês: Linear Matrix Inequalities), LMIs, que, quando factíveis, são facilmente resolvidas por meio de ferramentas disponíveis de programação convexa. Neste trabalho trata-se também da síntese via realimentação de estado com chaveamento no ganho que assegura o critério de desempenho Hoo. Para a validação das estratégias de controle mencionadas foram realizadas simulações e experimentos práticos em um sistema de suspensão ativa de bancada e em um sistema ball balancer, equipamentos fabricados pela Quanser. Os resultados comprovam a eficácia dos método propostos tanto nas simulações quanto nos testes realizados em bancada. / Mestre
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Controle chaveado e chaveado suave de sistemas não lineares incertos via modelos fuzzy T-S /Alves, Uiliam Nelson Lendzion Tomaz. January 2017 (has links)
Orientador: Marcelo Carvalho Minhoto Teixeira / Resumo: O controle chaveado pode ser eficientemente utilizado no controle de sistemas fuzzy TakagiSugeno (T-S) incertos, que possuam funções de pertinência incertas e modelos locais conhecidos. Como estes sistemas fuzzy podem representar exatamente uma classe de sistemas não lineares incertos em uma região do espaço de estados, é interessante utilizá-los para descrever sistemas não lineares, usando no projeto do controlador o modelo fuzzy que descreve exatamente o sistema não linear. Porém, como a representação através de combinação convexa obtida é válida apenas em uma região do espaço de estados, garantias de que o estado do sistema permaneça nessa região devem ser obtidas. Neste trabalho são propostas condições que garantem a estabilização local, com a especificação da taxa decaimento, de uma classe de sistemas não lineares contínuos no tempo, incertos e com saturação no atuador, utilizando o controle chaveado. Os projetos dos controladores são realizados com base no modelo fuzzy T-S que representa exatamente o sistema não linear e os procedimentos de projeto fornecem uma região na qual as condições iniciais devam estar, tal que, o sistema não linear seja exatamente descrito pelo modelo fuzzy T-S incerto durante toda a trajetória de estado do sistema e ainda que esta trajetória permaneça dentro de uma região de operação previamente especificada. Em geral, o controle chaveado não possui restrição na frequência de chaveamento dos ganhos, o que pode levar ao chattering, que se manife... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The switched control can be efficiently used for controlling uncertain Takagi-Sugeno (T-S) fuzzy systems, which have uncertain membership functions and known local models. Because these fuzzy systems can exactly represent a class of uncertain nonlinear systems in a given operation region in the state space, it is interesting to use them to describe nonlinear systems, performing the controller design based on a T-S fuzzy model that exactly describes the nonlinear system. However, the perfect representation of the uncertain nonlinear system by the T-S fuzzy model as a convex combination is only valid in the operation region. Therefore, it is necessary to assure conditions such that the state of the system remains in that region. This work proposes conditions to ensure the local stabilization, with decay rate, of a class of uncertain continuoustime nonlinear systems with saturation on the actuator, using a switched control. The designs of the controllers are performed based on the T-S fuzzy model which exactly describes the nonlinear system and the design procedures provide a region in which the initial conditions must be such that the nonlinear system is exactly described by the uncertain T-S fuzzy model along the whole state trajectory of the system and this trajectory remains in a specified operation region. Usually, the switched control has no bound on the frequency of the feedback gains switching, and this can lead to chattering, which is manifested by infinitely fast frequ... (Complete abstract click electronic access below) / Doutor
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Détection, localisation et estimation de défauts : application véhicule / Fault detection, isolation and estimation : Application to vehicle dynamicsFarhat, Ahmad 22 September 2016 (has links)
Dans la nécessité de développer des véhicules sûrs, confortables, économiques et à faible impact environnemental, les voitures sont de plus en plus équipées d'organes qui emploient des capteurs, actionneurs et systèmes de commande automatiques.Or ces systèmes, critiques pour la sécurité et le confort des passagers, peuvent mal-fonctionner en présence d'une défaillance (défaut).Dans le cadre du diagnostic à bord, plusieurs approches à base de modèle sont développées dans ce travail afin de détecter, localiser et estimer un défaut capteur ou actionneur, et pour détecter la perte de stabilité du véhicule.Ces méthodes reposent sur une synthèse robuste pour les systèmes incertains à commutation.Elles sont validées en simulation avec le logiciel CarSim, et sur les données réelles de véhicule dans le cadre du projet INOVE. / Modern vehicles are increasingly equipped with new mechanisms to improve safety, comfort and ecological impact. These active systems employ sensors, actuators and automatic control systems. However, in case of failure of one these components, the consequences for the vehicle and the passengers safety could be dramatic. In order to ensure a higher level of reliability within on board diagnosis, new methodologies for sensor or actuator fault detection, location and estimation are proposed. These model based approaches are extended for robust synthesis for switched uncertain systems. In addition, a method for detecting critical stability situation is presented. The validation of the different methods is illustrated with simulations using CarSim, and application on real vehicle data within the INOVE project.
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Nouveau modèle de planification industrielle et commerciale avec approvisionnement long dans l'industrie automobile : approche par simulation-optimisation / A new model for sales and operations planning with long procurement lead time in the automotive industry : a simulation-optimization approachLim, Lâm Laurent 14 May 2014 (has links)
Face à un environnement incertain et une internationalisation croissante de la chaîne logistique, la planification industrielle et commerciale (PIC) permet d’adapter efficacement les capacités industrielles à la demande du marché. Dans cette étude, nous présentons un modèle original de PIC utilisant des contraintes de flexibilité, pour améliorer la coordination entre les fonctions commerciales et logistiques. Un premier modèle de simulation permet d’étudier la dynamique du système ainsi que l’impact des différents paramètres sur les performances en termes de coûts et de satisfaction client. Afin d’étudier les politiques optimales, nous proposons un nouveau modèle de simulation-optimisation multi objectif. Différentes méthodes d’optimisation sont comparées, et plusieurs recommandations sont émises pour l’implémentation pratique de notre solution. Enfin, nous comparons les performances de plusieurs politiques de gestion des stocks lorsqu’elles sont couplées avec notre méthode de PIC flexible. À partir de données réelles du constructeur automobile Renault, nous présentons une étude comparative détaillée. Nous proposons plusieurs préconisations pratiques sur le type de politiques à privilégier selon les caractéristiques du système. Ces travaux de recherche sont particulièrement pertinents et applicables à d’autres industries confrontées à de fortes exigences commerciales,une faible visibilité sur la demande future et des approvisionnements longs. / Face to uncertain environment and growing globalization of the supply chains, the salesand operations planning (S&OP) aims to adapt efficiently the industrial capacities to themarket demand. In this research, we present an original S&OP model that uses flexibilityconstraints to improve the coordination between sales and logistics functions. A first simulationmodel is developed to study the system dynamics and the impact of different parameters onsystem’s performance in terms of costs and customer satisfaction. We introduce a multiobjectivesimulation-optimization model to investigate the optimal policies. Several optimization methodsare compared and recommendations are given for the practical implementation of our solution.Then, we compare the performances of several policies for managing parts inventories whenthey are coupled with our flexible S&OP. Based on real data of the automobile manufacturerRenault, we present a detailed comparative study. We present several managerial insights on thetype of policies to favor depending on the system characteristics. This research is particularlyrelevant for other industries that face strict customer requirements, uncertain demand and longprocurement lead time.
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