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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Desenvolvimento e implementação de controlodor fuzzy aplicado a produção de biodiesel / Development and implementation of fuzzy controller in biodiesel production

Carulo, Marcelle Fernanda 09 January 2008 (has links)
Orientador: Flavio Vasconcelos da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-11T16:12:00Z (GMT). No. of bitstreams: 1 Carulo_MarcelleFernanda_D.pdf: 2245621 bytes, checksum: 8f61c0294f8869a9c447fc5eaf81d6b7 (MD5) Previous issue date: 2008 / Resumo: A crescente utilização do biodiesel como combustível renovável e, principalmente, as situações de operação transiente, de característica complexa e não-linear, motivaram a implementação de um controlador digital avançado neste processo. O controlador avançado foi implementado em computador através de um sistema de comunicação digital, visando manter a temperatura da mistura reacional em 50 °C. A temperatura é uma variável importante deste processo devido à influência direta na taxa de conversão do óleo em biodiesel. Óleo de soja foi utilizado como fonte de ácidos graxos, além do uso do álcool etílico anidro e ácido sulfúrico como reagentes. A reação química foi acompanhada durante 1 hora de batelada visando assegurar uma boa conversão do óleo (acima de 90%). Neste trabalho, além do controlador avançado também foi implementado o controlador PID. Os parâmetros de sintonia do controlador PID foram obtidos em malha aberta e auxiliaram a sintonia do controlador fuzzy. Durante a etapa de sintonia fina do controlador fuzzy foram alteradas as funções de pertinência, o universo de discurso e a base de regras. A implementação do controlador fuzzy apresentou-se como uma ferramenta apropriada para o controle da temperatura reacional devido às complexidades advindas das variações dos parâmetros deste processo. A análise comparativa do desempenho dos controladores fuzzy e PID aplicados à produção de biodiesel comprovaram isso. O uso do controlador fuzzy reduziu o consumo de energia elétrica durante a batelada em 10% quando comparado ao parâmetro obtido para o controlador PID e também reduziu o tempo necessário para atingir a máxima conversão do óleo em biodiesel em 15 min / Abstract: The increasing use of biodiesel as a renewable fuel, and mainly because of their nonlinearity and time varying properties this work aimed the implementation and the development of an automation system based in fuzzy logic. In this work, the fuzzy controller is applied in the maintenance of the temperature of bulk at 50?C, using digital system. The control of the temperature in this process is important to guarantee the final quality of biodiesel. Soybean oil was used like source of fatty acids, ethanol and sulfuric acid were used like reagents. This reaction occured during an hour to can achieved high conversion (above 90%). The PID controller tuning parameters were obtained via open-loop experiments. The tuning the fuzzy controller can be achieved by modifying the rules, the discurse universe and the pertinence functions. Due the complexity and the nonlinearity of this reaction, the results of this study showed the effectiveness of fuzzy controller. The fuzzy controller reduced the energy consumption (10% smaller) and the batch time (15 min smaller) when compared to a PID controller / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química
12

VHDL návrh řídicí jednotky robota určeného pro samočinný pohyb v bludišti / VHDL Design of Robot Controller for Autonomous Robot Movement in Maze

Podivínský, Jakub January 2013 (has links)
This master thesis describes design and implementation of a robot controller for autonomous movement in a maze. Robot represents an exemplary system, which is designed for testing and validation of fault-tolerance methodologies. A part of this work contains introduction to reliability of digital systems, especially those which are based on Field Programmable Gate Array (FPGA). Moreover, this introduces techniques that ensure robustness against faults in digital systems; attention is devoted to the usage of FPGA technology in this area and a technique called partial dynamic reconfiguration.
13

La nouvelle esthétique de l'encre : une pratique de l'art lettré traditionnel chinois à l'épreuve du numérique / The new aesthetic of the Chinese ink : a practice of traditional Chinese literary art to test of the digital system

Ze, Yuefeng 13 November 2015 (has links)
Depuis la fin du XXe siècle, notre monde a été affecté par une grande mutation des activités humaines. Dans cette mutation, les sciences de la cognition jouent sans doute un rôle central. Le développement des sciences cognitives, surtout depuis sa phase de Seconde Cybernétique, fait émerger de nouveaux paradigmes et offrent au monde humain la nouvelle génération des technologies de l'informatique – le numérique. En parallèle avec les technologies numériques qui ont profondément transformé le rapport sensible de l’être humain au monde, les dispositifs scientifiques et conceptuels mis en œuvre dans la Seconde Cybernétique ont également provoqué un grand retentissement dans tous les domaines scientifiques et philosophiques occidentaux. Ces dispositifs nous conduisent à ré-évaluer les connaissances déjà modélisé dans le cadre de la modernité à partir d’une approche totalement nouvelle, celle du système évolutif. Le retentissement de la Seconde Cybernétique a un impact fort dans le domaine de l'art. D'une part, les technologies numériques offrent à la création artistique de nouveaux moyens techniques de modélisation de l'œuvre d'art en s'accompagnant de l'apparition de nouvelles expressions artistiques, de nouvelles esthétiques et de nouveaux enjeux pour les représentations artistiques. D'autre part, les dispositifs conceptuels et scientifiques mis en place par la Seconde Cybernétique ont conduit les théoriciens de l'art et les esthéticiens à réévaluer les phénomènes artistiques (l’œuvre d’art, l’activité artistique, la perception esthétique, l’évolution culturelle de l’art, etc.) dans une perspective totalement nouvelle de l’esprit : le naturalisme de l’esprit. Mes travaux tentent de proposer une réflexion sur l’œuvre d’art en relation avec la cognition à partir des dispositifs scientifiques, technologiques et conceptuels constitués dans le cadre de la Seconde Cybernétique, mais aussi à partir des dispositifs conceptuels issus de l’art lettré traditionnel chinois. Les deux paradigmes de pensées du réel, tout en étant à l'origine de deux cultures très éloignées et très différentes, révèlent par contre un même principe de l'appréhension du monde. À partir de ce principe, la réalité doit être analysée en tant que phénomène d’émergence en cours relevant d'un rapport d'interaction ; le monde se définirait comme réseau des relations dynamiques capables de s'auto-organiser pour l’émergence de nouvelles structures. Cette approche du réel nous conduit à reposer la question de l’œuvre d’art, à la fois en tant qu’objet de création et en tant qu’objet de réception esthétique, à partir des nouveaux paradigmes liés aux processus d’émergence comme processus biologiques ou processus numériques. Cette thèse peut être résumée par les quatre points suivants : 1. L’art relève d’une capacité cognitive créatrice qui résulte de la phylogenèse de l’espèce humaine et qui est individualisé par le développement ontologique de chaque personne. 2. L’art, comme culture, relève d’un système d’appréhensions cognitives du réel ; ce système s’organise dans le même principe que l’algorithme évolutionniste basé sur la variation, l’accumulation, la sélection darwinienne et l’hérédité. 3. L’œuvre d’art relève d’une extériorisation expressive de l’artiste, de ses états mentaux, de son imaginaire du réel se produisant dans son cerveau ; la création de l’œuvre d’art s’inscrit dans un processus d’émergence qui relève d’un rapport dialectique s’effectuant entre un schéma mental se produisant dans le cerveau de l’artiste et son extériorisation progressive en œuvre d’art par les actions. 4. Les systèmes numériques, à la fois en tant qu’outils technologiques autant que paradigme de représentations du monde, constituent une interface d’interaction entre les différentes cultures dans le cadre de la création artistique. / Since the end of 20th century, our world has been affected by a grand mutation of human activities. The cognitive science plays the central role without any doubt in this mutation. The development of the cognition science, especially since its second cybernetic phase, does emerge new paradigms and offers a new computer science generation, digitization, to the world. In parallel with the digital technologies that has profoundly transformed human senses to the world, the scientific and conceptual devices implemented in the second cybernetics have also caused a great impact in almost all scientific and occidental philosophic aspects. These devices made determinant concepts for all contemporary theories of evaluative system in the world. We propose to, based on this concept, revaluate all modelled knowledge in the context of modernity. The impact of the second cybernetics has a strong impact in the art’s field, as well as in the theoretical studies of the art in the creation of art’s works. On one hand, digital technology, especially the artificial intelligence systems and devices from the second cybernetics, provides the artistic creation of new techniques for modelling the artwork accompanied by the emergence of new arts, new look and new challenges for the performing arts. On the other hand, conceptual and scientific arrangements put in place by the second cybernetics, led the art theorists and designers to evaluate the artistic phenomena (the work of art, the artistic aesthetic perception, cultural evolution, art, etc.) in a totally new perspective in mind: naturalism of spirits. My work attempts to propose a reflection on the work of art related to cognition which based on scientific, technological and conceptual devices, set up within the framework of the second network device, but also from the ancient chinese concept from the mind, especially taoist and chinese lettered thoughts.The two paradigms of thinking, while the origin of the two cultures are very remote and different, but released from the same principle of the understanding of the world. Based on this principle, the reality must be analysed as a phenomenon of the emergence ; the world would be defined as a network of relationships and self organize to the emergence of new structures.This approach leads us to raise the question on the issue of work of art, at the same time as a subject of creation, as an object of esthetic reception and an artifact which is a network of intersubjective relations (culture), based on the new paradigms associated with processes of emergence like biological processes or digital processes. This thesis can be conclute by the four following points: 1. art is a creative cognitive ability, which is the result of the phylogeny of human beings and is tailored to the ontological development of each individual. 2. Art, like culture, releases a real concern cognitive system. this system is on the same principle as the evolutionary algorithm based on the change, the accumulation, darwinian selection and heredity. 3. the work of art is an representation of the artist's expression, of his mental states, of his imagination of the real occurring in his brain; the creation of a work of art is a part of the process of development which releases a dialectical relationship between a mental pattern produced in artist’s brain and his progressive expression of work of art. 4. the digital systems, at the same time as technological tools as well as the paradigm of representations of the world, build up an interface of interaction between different cultures in the context of artistic creation.

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