Academic literature on the topic 'Contrôle à retards'
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Journal articles on the topic "Contrôle à retards"
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Cerqueira, Thales Sandoval, Angelo Pedro Jacomino, Fabiana Fumi Sasaki, and Lilian Amorim. "Controle do amadurecimento de goiabas 'Kumagai' tratadas com 1-metilciclopropeno." Revista Brasileira de Fruticultura 31, no. 3 (September 2009): 687–92. http://dx.doi.org/10.1590/s0100-29452009000300010.
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A alta perecibilidade da goiaba é o principal problema enfrentado pelos produtores na comercialização da fruta in natura, tanto no mercado nacional, como no internacional. O 1-metilciclopropeno (1-MCP) é um regulador vegetal conhecido como bloqueador da ação do etileno, empregado para retardar o amadurecimento de frutos e estender sua vida útil. Assim, o presente trabalho teve por objetivo determinar os efeitos da aplicação do regulador vegetal 1-MCP sobre a qualidade pós-colheita de goiabas 'Kumagai'. As goiabas foram colhidas quando a cor da casca começou a mudar de verde-escura para verde-clara, tendo como base os índices de firmeza (N) e cor da casca (ºh) de 85N e 117ºh, respectivamente, em lotes uniformes, sem defeitos. Os frutos foram expostos ao 1-MCP durante 3 horas, em câmara hermética, nas concentrações de 0; 100; 300 e 900 nL.L-1 e armazenadas a 22±2 ºC e 80-85 %UR durante 12 dias. O regulador vegetal retardou a perda da cor verde da casca e da firmeza da polpa, bem como o incremento dos teores de ácido ascórbico e de sólidos solúveis, entretanto não alterou a perda de massa, a acidez titulável e a incidência de podridões. A atividade respiratória e a produção de etileno também foram influenciadas pelo 1-MCP, tendo atingido os menores valores ao empregar a maior concentração deste regulador vegetal. A aplicação de 1-MCP, nas concentrações de 300 a 900 nL.L-1, durante 3 horas, retarda o amadurecimento de goiabas 'Kumagai', prolongando sua vida pós-colheita.
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Vieira, Marcelo José, Luiz Carlos Argenta, Cassandro Vidal Talamini do Amarante, Cristiano André Steffens, and Amanda Maria Furtado Drehmer Vieira. "Preservação da qualidade pós-colheita de kiwi 'bruno' pelo controle do etileno." Revista Brasileira de Fruticultura 32, no. 2 (June 2010): 309–406. http://dx.doi.org/10.1590/s0100-29452010000200008.
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Objetivou-se determinar os efeitos do 1-MCP sobre a conservação pós-colheita de kiwi, cultivar Bruno, armazenado sob atmosfera do ar (AA) e atmosfera controlada (AC). Os frutos foram colhidos em abril de 2003 e 2004. Três dias após a colheita, parte dos frutos foi tratada com 1,0 µL.L-1 de 1-MCP e armazenada sob atmosfera do ar (AA) e AC com baixo etileno. O tratamento com 1-MCP retardou o aumento da taxa de produção de etileno e reduziu a respiração após remoção de câmara fria, resultando assim no retardo da perda de firmeza da polpa e na redução do desenvolvimento de pericarpo translúcido e senescente. O tratamento com 1-MCP não apresentou efeito significativo sobre os teores de sólidos solúveis. Frutos armazenados sob AA apresentaram alto metabolismo, resultando em baixo potencial de armazenamento, mesmo na presença do 1-MCP. Máxima conservação da qualidade pós-colheita de kiwi 'Bruno' foi observada em frutos tratados com 1-MCP e armazenados sob AC com baixo etileno.
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Enesco, Hildegard E. "Genetic Control of the Aging Process: A Review and Interpretation." Canadian Journal on Aging / La Revue canadienne du vieillissement 15, no. 1 (1996): 16–30. http://dx.doi.org/10.1017/s0714980800013258.
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RÉSUMÉLe processus de vieillissement est sous contrôle génétique. Le point de vue traditionnel, dérivé de la biologie évolutive, est que le vieillissement est un trait polygénique, contrôlé par un grand nombre de gènes, chacun avec un effet additif. Un autre point de vue est développé ici, en ajoutant qu'il y a un nombre limité de gènes importants dans le contrôle du vieillissement. Ces derniers peuvent inclure les gènes protecteurs qui assurent l'exactitude de la synthèse de protéines et aussi les gènes qui servent à activer ou à retarder le processus de vieillissement. On continue à développer la technologie génétique afin de faire la carte complète du génome humain. Ces percées offrent la possibilité de comprendre les mécanismes génétiques du vieillissement et même d'envisager la thérapie génétique pour les maladies associées au vieillissement.
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Mondié, Sabine, and Marco-Antonio Gomez. "Contribuciones al estudio de sistemas lineales con retardos: el enfoque de funcionales de tipo completo." Revista Iberoamericana de Automática e Informática industrial 19, no. 4 (May 23, 2022): 381–93. http://dx.doi.org/10.4995/riai.2022.16828.
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Se introducen resultados recientes del enfoque de funcionales de Lyapunov-Krasovski de tipo completo para sistemas lineales con retardos. Se explican brevemente los principales conceptos y resultados para el caso de sistemas con un retardo así como las condiciones necesarias y suficientes de estabilidad expresadas en terminos del análogo de la matriz de Lyapunov. Las extensiones de este tipo de condiciones de estabilidad a otras clases de sistemas con retardos son expuestas brevemente. Tambien se presentan aplicaciones existentes del efoque de funcionales de tipo completo a problemas de analisis y de diseño de controladores. El trabajo se enfoca a contribuciones de investigadores de Mexico a este tema de estudio.
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González, Antonio, and Antonio Sala. "Control predictor con ponderación de retardos: análisis de prestaciones y robustez ante retardo variable." Revista Iberoamericana de Automática e Informática Industrial RIAI 11, no. 2 (April 2014): 155–66. http://dx.doi.org/10.1016/j.riai.2013.11.008.
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Gomes, Samara Silva, Augusto César Cristo de Carvallho, and Cristiane Maria Varela Araujo-Castro. "Efeitos Agudos e Crônicos Durante e Após a Exposição do Copepoda Tisbe biminiensis ao Cromo." Fronteiras: Journal of Social, Technological and Environmental Science 8, no. 1 (February 22, 2019): 341–52. http://dx.doi.org/10.21664/2238-8869.2019v8i1.p341-352.
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Fêmeas ovadas foram expostas a quatro diferentes concentrações de cromo durante 96 horas. Posteriormente, as fêmeas foram transferidas para água de cultivo (descontaminação) durante oito dias. Na exposição foram observados parâmetros reprodutivos e mortalidade. Na descontaminação foi avaliado o sucesso reprodutivo das fêmeas (tempo para produção de saco de ovos e número de náuplios), desenvolvimento da prole e parâmetros populacionais. Durante a exposição não foram observadas mudanças significativas nos parâmetros avaliados. No bioensaio de descontaminação, as fêmeas do grupo controle demonstraram normalidade no comportamento reprodutivo, enquanto que as fêmeas expostas ficaram desovadas por mais tempo reduzindo a produção de náuplios. Com relação ao desenvolvimento, observou-se um retardo nas transições dos estágios larvais, sobretudo de copepodito para adulto, demonstrando uma menor densidade populacional. Portanto, concentrações subletais de cromo podem prejudicar a fisiologia reprodutiva, retardar o desenvolvimento e diminuir a densidade populacional de Tisbe biminiens.
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Ben Hamouda, M., and M. Rekik. "contrôle de croissance des ovins allaitants en Tunisie. ii. Perte de précision sur le calcul des performances à âge type selon un protocole simplifié alternatif au protocole officiel." Revue d’élevage et de médecine vétérinaire des pays tropicaux 65, no. 1-2 (January 1, 2012): 41. http://dx.doi.org/10.19182/remvt.10131.
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Les performances à âge type P10 (poids à 10 jours), P30, P70, GMQ10/30 (gains moyens quotidiens entre 10 et 30 jours) et GMQ30/70 de 9 642 agneaux de race Barbarine ont été calculées selon le protocole conventionnel « F2 », ou un protocole simplifié, basé sur l’ajustement de la fonction von Bertalanffy à deux pesées à 42 jours d’intervalle, la première ayant lieu entre 2 et 60 jours après la naissance de l’agneau, et un poids à la naissance réel (PNR : contrôlé à la naissance), fixé, le même pour tous les agneaux (PNF = 3,4 kg) ou estimé en fonction de la première pesée (P) et l’intervalle entre la naissance et la première pesée (D) [PNE = 2,71009 + 0,208313 P – 0,00578 P (60 – D) + 0,00016 P (60 – D)2]. La perte de précision moyenne associée au calcul des poids à âge type a été élevée pour P10 (40 à 45 p. 100), modérée pour P30 (6 à 7 p. 100) et faible pour P70 (2 à 3 p. 100). La perte de précision associée au GMQ10/30 a été inférieure à celle déjà admise par le protocole conventionnel pour un intervalle entre la naissance et le premier contrôle compris entre 15 et 45 jours (15 p. 100 au maximum), et du même ordre entre 7 et 15 jours d’intervalle (20 p. 100 au maximum). Ces résultats ont permis de proposer la simplification du protocole F2 à deux ou trois pesées et un poids à la naissance. La première pesée devrait être retardée jusqu’à 46 jours après la naissance alors que l’intervalle entre contrôles successifs peut varier entre 30 et 40 jours, en fonction de la perte de précision pouvant être tolérée sur l’estimation des performances à âge type.
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Boy, Raquel, Patrícia Santana Correia, Juan Clinton Llerena, Maria do Carmo Machado-Ferreira, and Márcia Mattos Gonçalves Pimentel. "Síndrome do X frágil: estudo caso-controle envolvendo pacientes pré e pós-puberais com diagnóstico confirmado por análise molecular." Arquivos de Neuro-Psiquiatria 59, no. 1 (March 2001): 83–88. http://dx.doi.org/10.1590/s0004-282x2001000100017.
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A síndrome do X frágil é a causa mais comum de retardo mental herdado; entretanto, é subdiagnosticada na população pediátrica. Objetivamos, neste estudo, determinar as características clínicas pré e pós-puberais mais significativas observadas entre indivíduos que apresentam a mutação no gene FMR-1, e que possam ser utilizadas como método de triagem dos pacientes que devem ser submetidos à análise molecular. A partir de protocolo clínico-laboratorial, foram analisados 104 indivíduos (92 do gênero masculino e 12 do feminino) portadores de retardo mental idiopático. 17 pacientes (14 do gênero masculino) apresentaram a mutação completa. História familiar de retardo mental e contato ocular pobre foram os achados que se mostraram associados, de forma estatisticamente significante (p<0,05), aos pacientes com a síndrome do X frágil em idade pré e pós-puberal. Os pacientes em idade pós-puberal também diferiram dos controles em relação à presença de orelhas grandes, fronte proeminente e macroorquidismo.
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Dallora Neto, Caetano, Gilda Carneiro Ferreira, and João Carlos Dourado. "Utilização de sismógrafos de engenharia como ferramenta no controle de qualidade de acessórios de detonação não elétricos." Rem: Revista Escola de Minas 61, no. 2 (June 2008): 185–92. http://dx.doi.org/10.1590/s0370-44672008000200012.
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Nesse artigo, são apresentados os trabalhos realizados com o objetivo de verificar se a elevada dispersão dos valores de velocidade de partícula obtidos durante monitoramentos de vibrações decorrentes de desmontes de rocha com a utilização de explosivos, em mineração localizada no município de Limeira (SP), vinculava-se a variações nos tempos dos elementos de retardo dos acessórios de detonação em relação aos nominais. Os experimentos foram realizados em janeiro e junho de 2004. O procedimento adotado para estimar os tempos de retardo de acessórios de detonação não elétricos redundou em resultados que apresentam consistência, necessitando, porém, de estudos mais aprofundados. Os dados obtidos indicam a necessidade de considerar sua ocorrência quando da elaboração de planos de fogo, por suas implicações: ambientais, que inclui aspectos relativos à segurança e econômicas.
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Maia, Carlos Andrey, Ricardo Lüders, Rafael Santos Mendes, and Laurent Hardouin. "Estratégias de controle por modelo de referência de sistemas a eventos discretos Max-plus Lineares." Sba: Controle & Automação Sociedade Brasileira de Automatica 16, no. 3 (September 2005): 263–78. http://dx.doi.org/10.1590/s0103-17592005000300001.
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Este artigo trata do controle de sistemas a eventos discretos modelados pela álgebra Max-plus. Esta abordagem é usada para descrever processos cuja dinâmica seja caracterizada por retardos no tempo e fenômenos de sincronização. Exemplos típicos desses processos são as linhas de montagem em sistemas de manufatura. O problema de controle estudado está relacionado à estratégia ''just-in-time'' em planejamento da produção. Neste artigo tutorial, diversas estratégias baseadas na abordagem por modelo de referência são apresentadas, exemplificadas e discutidas.
Dissertations / Theses on the topic "Contrôle à retards"
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Clerget, Charles-Henri. "Contributions au contrôle et à l'optimisation dynamique de systèmes à retards variables." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM053/document.
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Dans cette thèse, nous avons étudié le contrôle et l'optimisation de systèmes dynamiques sujets à des retards variables.L'existence de retards, de commande ou d'état, est un problème classique en automatique, susceptible de réduire les performances du système en régime transitoire, voire de remettre en cause la stabilité de contrôleurs en boucle fermée. De tels phénomènes de retards variables jouent un rôle important dans de nombreuses applications en génie des procédés.Dans une première partie, nous avons étudié la régulation en boucle fermée d'un système soumis à des retards de métrologie variables et incertains. Nous avons établi de nouveaux résultats garantissant la stabilité robuste sous certaines conditions explicites sur le gain du contrôleur. Dans une seconde partie, nous avons abordé le problème de l'optimisation dynamique de systèmes présentant des retards variables dépendant de la commande liés à des phénomènes de transport dans des réseaux hydrauliques. Nous avons proposé un algorithme itératif d'optimisation et garanti sa convergence grâce à une analyse détailléeThis Ph.D. work studied the control and optimization of dynamical systems subject to varying time delays.State and control time delays are a well-known problem in control theory, with a potential to decrease performances during transient regimes, or even to jeopardize controllers closed-loop stability. Such variable delays play a key role in many applications in process industries.In a first part, we studied the closed-loop control of a system subject to varying and uncertain metrology delays. We established new results on robust stability under explicit conditions on the controller gain. In a second part, we tackled the problem of the dynamic optimization of systems exhibiting input dependent delays due to transport phenomena in complex hydraulic architectures. We designed an iterative optimization algorithm and guaranteed its convergence through a detailed analysis
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Barraud, Julien. "Commande de procédés à paramètres variables." Phd thesis, École Nationale Supérieure des Mines de Paris, 2006. http://pastel.archives-ouvertes.fr/pastel-00002192.
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Le travail présenté dans ce manuscrit s'inscrit dans le cadre de la commande temps réel de certains procédés du raffinage. Nous présentons les travaux réalisés sur la commande monovariable et la gestion des paramètres variables. La première partie des travaux s'est articulée autour de l'étude d'un article apparu en 2003. Nous avons comparé les méthodes de commande monovariable proposées dans cet article avec d'autres méthodes plus communément utilisées. Dans le but améliorer les performances obtenues avec les outils testés, nous avons mis au point un prédicteur de Smith adaptatif dans lequel le retard est mis à jour à partir de considérations physiques d'un procédé d'hydrodésulfuration. Nous nous intéressons aussi au problème ouvert de la commande d'un procédé de mélange, qui comporte plusieurs volumes morts entre les bacs de bases et la mélangeuse. Nous avons montré qu'il était possible de reconstruire, en choisissant un estimateur adapté, les propriétés en sortie de mélangeuse. La méthode a été mise en place et est utilisée sur une mélangeuse réelle. Nous avons également travaillé sur la commande d'un procédé de neutralisation de pH. L'approche que nous avons eue du problème est double. D'un côté, nous avons travaillé directement sur le procédé, de l'autre, nous avons élaboré un modèle non linéaire à partir duquel nous avons mis en place une loi de commande non linéaire. La loi de commande utilisée pour réguler le pH mesuré au pH de consigne intègre les non linéarités du procédé ce qui permet à l'utilisateur de changer de conditions opératoires sans avoir de modifications à apporter aux réglages de celle-ci.
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Nouasse, Houda. "Gestion supervisée de systèmes étendus à retards variables : cas des réseaux hydrographiques." Thesis, Toulouse, INPT, 2015. http://www.theses.fr/2015INPT0001/document.
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De part et d’autre de la Terre, on observe de plus en plus de phénomènes naturels dévastateurs, parmi lesquels les inondations constituent l’une des catastrophes les plus fréquentes. Ces dernières décennies d’importantes inondations ont été induites par les crues de rivières. Ces crues, dues à des pluies excessives ou aux eaux de ruissellement, causent sans cesse des pertes de vies humaines et des dégâts matériels importants. Pour remédier à ces problèmes, les réseaux hydrographiques sont de plus en plus équipés de moyens de détection de crues. Un facteur essentiel à la gestion de tels phénomènes est la réactivité. En effet, les gestionnaires des réseaux hydrographiques, dans ce genre de situation, doivent prendre rapidement des décisions importantes dans un contexte incertain, car la plupart de ces crues sont le fruit de phénomènes climatiques brusques, dont l’ampleur est difficile à évaluer avec précision. Nous proposons, dans ce mémoire, une méthode de gestion des crues dans des réseaux hydrographiques équipés de zones inondables contrôlées par des portes gravitationnelles. Dans un premier temps, nous avons modélisé notre méthode de gestion à l’aide d’un réseau de transport statique. Dans un second temps, nous l’avons enrichi en utilisant les réseaux de transport à retards dans le but de prendre en compte les temps de déplacement de la ressource gérée. Afin de pallier le problème de la taille importante des réseaux de transport à retards, nous avons élaboré un mécanisme de substitution combinant un réseau de transport statique réduit et une matrice de temporisation. De plus, ce mécanisme autorise la prise en compte des temps de transfert variables dépendant des débits, sans modification ni du réseau de transport, ni de la structure de la matrice de temporisation. Ce mécanisme permet donc une gestion simplifiée des temps de transferts, variables ou non. Avec ce mécanisme, l’évaluation du flot maximal à coût minimum, nous a permis, suivant les stratégies de gestion considérées, de consigner l’ouverture des portes des zones inondables afin d’écrêter la crue mais aussi afin de restituer cette eau stockée au moment opportun. Finalement, afin d’évaluer les apports de cette gestion, la méthode a été appliquée sur un cas d’étude basée sur un tronçon de rivière équipé de trois zones inondables et modélisé à l’aide de simulateurs hydrauliques combinant les approches de modélisation 1D et 2D. Les résultats de simulation obtenus ont montré que l’approche proposée permettait de réduire de manière significative les inondations en aval des cours d’eauOn either side of the Earth, we observe more and more devastating natural phenomena. Amon these phenomena, floods are one of the most frequent and devastating natural disasters. During these last decades extensive flooding were caused by the flood of rivers. These floods due to excessive rainfall or runoff induce invariably the loss of human lives and material damages. To overcome these problems, water systems are increasingly equipped with means for detecting floods. A key factor in the management of such phenomena is responsiveness. Indeed, managers of river systems, faced to this kind of situation should quickly take important decisions in an uncertain context, as most of these floods are induced by abrupt climate events, whose magnitude is difficult to assess accuracy. We propose in this dissertation, a method of flood management in river systems equipped with flood zones controlled by gravitational gates. At first, we modeled our management method using a static transportation network. In a second step, we enriched it by using transportation networks with delays in order to take into account the travel time of the managed resource. The main difficulty of transportation networks with delays is their oversize. To overcome this problem, we developed an alternative mechanism combining a static reduced transportation network with a temporization matrix. Furthermore, this mechanism allows the consideration of variable time transfer depending on flows, without modification either on the transportation network, or on the structure of the temporization matrix. This mechanism allows simplified management of the transfer times, variable or not. With this mechanism, the evaluation of the minimum cost maximum flow allowed us, according to the management strategies considered, to compute the gate opening for floodplains in order to mitigate the flood but also to restore the water stored at the relevant time. Finally, to evaluate the contributions of this management, the method was applied to a case study based on a section of river equipped with three flood control reservoirs areas modeled using hydraulic simulators combining 1D and 2D models. The simulation results showed that the proposed approach allowed reducing significantly the floods downstream watercourses
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Hernández-Díez, José-Enrique. "Delay-Based Controllers Design for Dynamical Systems." Thesis, Lyon, 2021. https://tel.archives-ouvertes.fr/tel-03269160.
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Cette thèse étudie l'utilisation de contrôleurs basés sur le retard pour les systèmes dynamiques. Quelques applications, quelques expériences, ainsi que des problèmes et des solutions théoriques sont abordés. L'accent principal de l'étude est mis sur la conception de contrôleurs basés sur le retard inspirés des contrôleurs PID. Plus précisément, nous développons des méthodes pour trouver le bon choix des paramètres du contrôleur assurant la stabilité pour différents types de contrôleurs. À cette fin, la thèse embrasse l'utilisation de modèles et d'analyses différentielles linéaires en raison de son élégante interprétation basée sur la fréquence. À cet égard, les propriétés de stabilité de ces systèmes sont régies par leur équation caractéristique, qui pour les systèmes à retards sont des quasi-polynômes. Ainsi, cette thèse étudie le comportement des racines de ces fonctions par rapport aux variations de leurs paramètres (coefficients du système et valeurs de retard) à travers des racines bien connues croisant la stabilité. Des méthodes numériques et des observations analytiques sont développées dans ce sens. En particulier, nous étudions les applications, les convertisseurs cc/cc, le pendule de Furuta, les dispositifs haptiques, et le problème MPPT-PV (maximum power point tracking - photovoltaic). Grâce à l'utilisation des régulateurs proportionnel-retard, proportionnel- dérivé basé sur retard, proportionnel-intégral retardé et proportionnel-retard-intégral. Nous proposons également une solution au problème classique de contrôle basé sur le retard, qui consiste à stabiliser une chaîne d'un nombre quelconque d'oscillateurs en appliquant un seul bloc de retardThis thesis studies the use of delay-based controllers for dynamical systems. Applications, experimentation, and theoretical problematics are addressed. The main focus of the study is the conception of delay-based controllers inspired by the well-known PID controllers. Also, and equally important, we study the design of such controllers. More precisely, we develop methods to find the proper choice of the controller's parameters assuring stability for different types of controllers. To this end, the thesis embraces the use of linear differential models and analysis due to its elegant frequency-based interpretation. In this regard, the stability properties of these systems are governed by their characteristic equation, which for time-delay systems are the so-called quasi-polynomials or polynomials with constant coefficients. Thus, this thesis studies the behavior of the roots of these functions with respect to variations of their parameters (coefficients and time delay values) through well-known roots crossing stability. Numeric methods and analytical observations are developed in this sense. In particular, we study applications, dc/dc converters, the Furuta pendulum, haptic devices, and the MPPT-PV (maximum power point tracking - photovoltaic) problem. Through the use of the proportional-delayed, proportional-delay-based derivative, proportional-delayed integral, and proportional-delayed-integral controllers. Also, we propose a solution to the classical delay-based control problem of stabilizing a chain of any number of oscillators by applying a single delay block
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Petit, Nicolas. "Systèmes à retards : platitude en génie des procédés et contrôle de certaines équations des ondes." Phd thesis, École Nationale Supérieure des Mines de Paris, 2000. http://pastel.archives-ouvertes.fr/pastel-00000791.
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Le travail s'inscrit dans le cadre de la platitude, théorie récente dans le domaine du contrôle des systèmes. Nous présentons des réalisations industrielles en génie des procédés et des contributions théoriques dans le domaine des équations aux dérivées partielles. A partir d'applications industrielles réalisées avec le groupe TotalFinaElf et aujourd'hui en service dans les usines concernées, nous montrons l'intérêt pratique de la platitude dans le domaine du contrôle des procédés : gestion de grands transitoires, prise en compte explicite des non linéarités, des retards, des contraintes. Nous traitons ensuite un ensemble d'exemples physiques de systèmes régis par des équations des ondes. En réécrivant ces équations aux dérivées partielles et leurs conditions limites comme des équations à retards, nous exhibons une paramétrisation de leurs trajectoires établissant ainsi la propriété de platitude de ces systèmes. Il est alors possible de prouver de maniéré constructive la commandabilite de ces systèmes en calculant des trajectoires entre différents états. Tous ces exemples, ou les retards jouent des rôles à chaque fois différents, nous permettent de mettre en valeur l'importance pratique et théorique de la propriété de platitude dans le domaine du génie des procédés et du contrôle des équations des ondes.
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Feingesicht, Maxime. "Contrôle non linéaire actif d’écoulements turbulents décollés : Théorie et expérimentations." Thesis, Ecole centrale de Lille, 2017. http://www.theses.fr/2017ECLI0024/document.
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Le contrôle des écoulements est un domaine en forte croissance visant à modifier un écoulement à l’aide d’actionneurs et d’algorithmes de contrôle. Un axe important du contrôle des écoulements est le contrôle des décollements car le décollement de la couche limite provoque des augmentations de traînée et donc des pertes énergétiques et des coûts en carburant. Cette thèse vise à développer des algorithmes de contrôles pour le recollement des écoulements à l’aide de jets pulsés. La première partie de cette thèse expose une technique d’identification de modèle basée sur des données expérimentales. Les modèles sont déduits de considérations physiques et de l’Automatique. Ils offrent une bonne correspondance aux données tout en restant simple et en contenant peu de coefficients. La seconde partie de cette thèse utilise ces modèles pour élaborer deux algorithmes de contrôle : le premier est un contrôle optimal en boucle ouverte et le second un contrôle robuste en boucle fermée. Ces algorithmes ont été implémentés sur diverses maquettes expérimentales (LML, ONERA, LAMIH) et leurs propriétés a été testée expérimentalement. Les tests ont été réalisés en utilisant un Arduino Uno pour les mesures et le calcul du contrôle, ce qui montre que la méthode développée est simple à appliquer et requiert peu de puissance de calculFlow control is a strongly growing field aiming at modifying fluid flows using actuators and control algorithms. An important part of flow control is the control of flow separation as boundary layer separation increases drag and therefore energy losses and fuel consumption. This thesis focuses on developing control algorithms for flow reattachment using pulsed jets actuators. The first part of this work develops a model identification technique based on experimental data. The models are derived from physical and control theory considerations. They provide a good fit to the data while remaining simple and using few coefficients. The second part of this work uses this models in order to design two different control algorithms : the first one is an optimal feedforward control while the second one is a robust feedback control. The control algorithms have been applied on several experimental setups (LML, ONERA, LAMIH) and their properties have been experimentally tested. The tests were conducted using a simple Arduino Uno for the measurements and computation of the control, showing that the developed method is easy to apply and requires very few computational resources
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Ariba, Yassine. "Sur la stabilité des systèmes à retards variant dans le temps : théorie et application au contrôle de congestion d'un routeur." Phd thesis, Université Paul Sabatier - Toulouse III, 2009. http://tel.archives-ouvertes.fr/tel-00442454.
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Cette thèse s'inscrit dans une thématique pluridisciplinaire explorant les liens existants entre la théorie de la commande et les réseaux informatiques. L'idée consiste à appliquer les outils de l'Automatique pour la stabilisation du trafic dans les réseaux de communication. Premièrement, nous nous sommes intéressés à l'analyse de stabilité des systèmes à retards variables au travers de deux approches temporelles. D'une part, nous avons considéré la méthode de Lyapunov-Krasovskii dans laquelle nous avons élaboré des fonctionnelles en adéquation avec de nouvelles modélisations du système (segmentation du retard, dérivée temporelle). D'autre part, la stabilité a également été abordée avec une approche entrée-sortie, empruntant alors les outils de l'analyse robuste. Le système à retard est alors réécrit comme l'interconnexion d'une application linéaire avec une matrice constituée d'opérateurs définissant le système original. Après avoir revisité le principe de séparation quadratique, nous développons des opérateurs auxiliaires afin de caractériser au mieux la dynamique retardée et proposer des critères moins pessimistes. Deuxièmement, la méthodologie développée est ensuite utilisée pour le problème de contrôle de congestion d'un routeur lors de communications TCP. Ce protocole de bout en bout est sensible à la perte de paquet et modifie en conséquence son taux d'émission selon l'algorithme du AIMD. Il s'agit alors de commander le taux de perte par l'intermédiaire d'un mécanisme d'Active Queue Management situé au niveau du routeur afin de réguler le trafic. Les résultats théoriques sont ensuite évalués à l'aide du simulateur de réseaux NS-2.
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Auriol, Jean. "Contrôle robuste d'EDPs linéaires hyperboliques par méthodes de backstepping." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEM011/document.
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Les systèmes d'Equations aux Dérivées Partielles Hyperboliques Linéaires du Premier Ordre (EDPs HLPO) permettent de modéliser de nombreux systèmes de lois de conservation. Ils apparaissent, par exemple, lors de la modélisation de problèmes de trafic routier, d'échangeurs de chaleurs, ou de problèmes multiphasiques. Différentes approches ont été proposées pour stabiliser ou observer de tels systèmes. Parmi elles, la méthode de backstepping consiste à transformer le système originel en un système découplé pour lequel la synthèse de la loi de commande est plus simple. Les contrôleur obtenus par cette méthode sont explicites.Dans la première partie de cette thèse, nous présentons des résultats généraux de théorie des systèmes. Plus précisément, nous résolvons les problèmes de stabilisation en temps fini pour une classe générale d'EDPs HLPO. Le temps de convergence minimal atteignable dépend du nombre d'actionneurs disponibles. Les observateurs associés à ces contrôleurs (nécessaires pour envisager une utilisation industrielle de tels contrôleurs) sont obtenus via une approche duale. Un des avantages importants de l'approche considérée dans cette thèse est de montrer que l'espace généré par les solutions de l'EDPs HLPO considérée est isomorphe à l'espace généré par les solutions d'une système neutre à retards distribués.Dans la seconde partie de cette thèse, nous montrons la nécessité d'un changement de stratégie pour résoudre les problèmes de contrôle robuste. Ces questions surviennent nécessairement lorsque sont considérées des applications industrielles pour lesquelles les différents paramètres du système peuvent être mal connus, pour lesquelles des dynamiques peuvent avoir été négligées, de même que des retards agissant sur la commande ou sur la mesure, ou encore pour lesquels les mesures sont bruitées. Nous proposons ainsi quelques modifications sur les lois de commande précédemment développées en y incorporant plusieurs degrés de liberté permettant d'effectuer un compromis entre performance et robustesse. L'analyse de stabilité et de robustesse sous-jacente est rendue possible en utilisant l'isomorphisme précédemment introduitLinear First-Order Hyperbolic Partial Differential Equations (LFOH PDEs) represent systems of conservation and balance law and are predominant in modeling of traffic flow, heat exchanger, open channel flow or multiphase flow. Different control approaches have been tackled for the stabilization or observation of such systems. Among them, the backstepping method consists to map the original system to a simpler system for which the control design is easier. The resulting controllers are explicit.In the first part of this thesis, we develop some general results in control theory. More precisely, we solve the problem of finite-time stabilization of a general class of LFOH PDEs using the backstepping methodology. The minimum stabilization time reachable may change depending on the number of available actuators. The corresponding boundary observers (crucial to envision industrial applications) are obtained through a dual approach. An important by-product of the proposed approach is to derive an explicit mapping from the space generated by the solutions of the considered LFOH PDEs to the space generated by the solutions of a general class of neutral systems with distributed delays. This mapping opens new prospects in terms of stability analysis for LFOH PDEs, extending the stability analysis methods developed for neutral systems.In the second part of the thesis, we prove the necessity of a change of strategy for robust control while considering industrial applications, for which the major limitation is known to be the robustness of the resulting control law to uncertainties in the parameters, delays in the loop, neglected dynamics or disturbances and noise acting on the system. In some situations, one may have to renounce to finite-time stabilization to ensure the existence of robustness margins. We propose some adjustments in the previously designed control laws by means of several degrees of freedom enabling trade-offs between performance and robustness. The robustness analysis is fulfilled using the explicit mapping between LFOH PDEs and neutral systems previously introduced
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Wang, Chunan. "Essays on Delay Reduction Contract, Airline Networks and Agricultural Land Marketization." Thesis, Toulouse 1, 2017. http://www.theses.fr/2017TOU10024/document.
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Cette thèse se compose de trois articles autonomes, dont chacun correspond à un chapitre. Le premier chapitre, écrit conjointement avec Estelle Malavolti, étudie la conception optimale du contrat de réduction des retards signé entre un ANSP et une compagnie aérienne monopoliste. Dans la conception du contrat, nous considérons principalement le problème d’antisélection. En outre, nous effectuons une analyse comparatif-statique pour étudier les effets de la norme de sécurité et de la fréquence de vol sur les contrats optimaux. A la fin, nous utilisons des exemples numériques pour étudier le cas où un ANSP maximisant son bien-être doit utiliser des fonds publics pour fournir le service. Le deuxième chapitre étudie le double rôle des retards de congestion et de la différenciation horizontale des produits dans le choix du réseau aérien. Je trouve que, premièrement, en raison de l’inclusion des retards de congestion, la compagnie aérienne peut choisir le réseau point à point lorsque la désutilité des services avec une escale, engendrée par le temps supplémentaire du voyage, est relativement faible. Deuxièmement, sans tenir compte des investissements fixes de la compagnie aérienne dans le développement d’un aéroport de hub, le réseau 2-hub dominera les trois autres structures de réseau aussi longtemps que cela sera possible, car il implique la différenciation horizontale des produits sur plus de marchés que les trois autres structures de réseau. Le troisième chapitre, écrit conjointement avec Wanjun Yao et Shigeyuki Hamori, trouve empiriquement que l’efficacité de l’allocation des terres plus élevée améliore la productivité des terres moyenne de 29,1% et la plus grande taille de la ferme opérationnelle moyenne réduit la productivité des terres moyenne de 9,2%, ce qui implique que la commercialisation des terres agricoles en Chine améliore finalement la productivité des terres moyenne de 19,9%This thesis consists of three self-contained papers, each of which corresponds to one chapter. The first chapter, jointly written with Estelle Malavolti, studies the optimal design of delay reduction contract signed between an ANSP and a monopoly airline. In the contract design, we mainly consider the adverse selection problem. Moreover, we conduct comparative-static analysis to study the effects of safety standard and flight frequency on optimal contracts. Besides, we use numerical examples to study when a welfare-maximizing ANSP has to use public funds to provide the service. The second chapter investigates the dual roles of congestion delays and horizontal product differentiation in airline network choice. I find that, first, because of the inclusion of congestion delays, the airline may choose the point-to-point network even when the extra travel time disutility of one-stop services is relatively low. Second, without considering the airline's fixed investments of developing a hub airport, the 2-hub network will dominate the three other network structures as long as it is feasible, as it involves the horizontal product differentiation in more markets than the three other network structures. The third chapter, jointly written with Wanjun Yao and Shigeyuki Hamori, empirically finds that the higher land allocation efficiency improves the average land productivity by 29.1% and the larger average operational farm size reduces the average land productivity by 9.2%, implying that the agricultural land marketization in China finally improves the average land productivity by 19.9%
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Hetel, Laurentiu. "Stabilité et commande robuste des systèmes à commutation." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2007. http://tel.archives-ouvertes.fr/tel-00202479.
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Les travaux de cette thèse portent sur l'analyse de stabilité et la synthèse de commandes robustes pour les systèmes linéaires à commutation en temps discret avec des incertitudes polytopiques et des incertitudes sur la loi de commutation. On considère des lois de commutations arbitraires et on montre que l'utilisation des fonctions de Lyapunov commutées dépendant de paramètres permet de déterminer des critères de stabilité et de stabilisation robuste moins conservatifs. Ensuite, des conditions de stabilité robuste pour les systèmes en temps discret avec une loi de commutation incertaine sont présentées en termes de temps minimum de séjour. Les résultats obtenus s'avèrent utiles dans le contexte de la commande numérique des systèmes continus en présence d'imprécisions sur les instants d'échantillonnage etl'application des commandes. Nous montrons comment une modélisation à base d'évènements permet de ramener le problème original à un problème spécifique aux systèmes à commutation avec des incertitudes polytopiques. Les résultats sont étendus au cas des systèmes à commutation continus commandés par des correcteurs numériques.
Books on the topic "Contrôle à retards"
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Hylton, Judith. SAFE, stopping AIDS through functional education. Portland, Or: Oregon Health Sciences University, Child Development and Rehabilitation Center, University Affiliated Program, 1990.
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Smart nursing: How to create a positive work environment that empowers and retains. New York: Springer Pub., 2005.
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Harris, Frances. 1709–1710. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198802440.003.0012.
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The tenth chapter describes how peace slips from the Allies’ grasp. Louis XIV refuses to join in driving his grandson out of Spain; Marlborough refuses to mediate between the Dutch and the Habsburgs; and the Whig financiers reject a separate peace with France with a campaign to get Spain afterwards. Another battle at Malplaquet fails to solve the impasse. Marlborough withdraws from his diplomatic and ministerial roles. Godolphin, having completed his bargain with the Whigs by getting Orford into the Admiralty, feels himself master of them, but Marlborough contests control of the army with the queen (the Essex regiment crisis) and tries unsuccessfully to use the Whig majority in Parliament to drive Abigail Masham from court. The queen, advised by Harley behind the scenes, is now convinced Marlborough is a threat to her and has turned completely against his wife, though Godolphin retains her confidence.
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Fabre, June. Smart Nursing: How to Create a Positive Work Environment That Empowers and Retains Nurses. Springer Publishing Company, Incorporated, 2005.
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Fabre, June. Smart Nursing: How to Create a Positive Work Environment That Empowers and Retains Nurses. Springer Publishing Company, Incorporated, 2010.
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Schütze, Robert. From International to Federal Market. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198803379.001.0001.
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What philosophy informs the European Union’s internal market? In the history of European integration three market models can be distinguished: an international model, a federal model, and a national model. Under the international model, each State commits itself to limiting its external sovereignty, while it retains internal sovereignty over its national market. By contrast, the federal model accepts that within a ‘common market’ States must lose a part of their internal sovereignty; and in line with the principle of ‘home state’ control, goods are generally entitled to be freely sold on a ‘foreign’ market once they comply with the law of their home state. Finally, according to the ‘national’ market model, all trade restrictions that are above a—legislative or judicial—Union standard must be removed. The book argues that the EU internal market—and in particular the structure of its law—has generally evolved from an international to a federal market philosophy.
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Beninger, Richard J. Drug abuse and incentive learning. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198824091.003.0010.
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Drug abuse and incentive learning explains how abused drugs, including nicotine, ethanol, marijuana, amphetamine, cocaine, morphine, and heroin, produce conditioned place preference and are self-administered; dopamine receptor antagonists block these effects. Stimuli that become reliable predictors of drug reward produce burst firing in dopaminergic neurons, but the drug retains its ability to activate dopaminergic neurons. Thus, repeated drug users experience two activations of dopaminergic neurotransmission, one upon exposure to the conditioned stimuli signaling the drug and another upon taking the drug. This may lead to long-term neurobiological changes that contribute to withdrawal and addiction. Withdrawal can be remediated by abstinence but this does not reduce the conditioned incentive value of cues associated with drug taking; those cues can lead to relapse. Effective treatment will include detoxification and systematic exposure to drug taking-associated conditioned incentive stimuli in the absence of drug so that those stimuli lose their ability to control responses.
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Contois, Emily J. H. Diners, Dudes, and Diets. University of North Carolina Press, 2020. http://dx.doi.org/10.5149/northcarolina/9781469660745.001.0001.
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The phrase "dude food" likely brings to mind a range of images: burgers stacked impossibly high with an assortment of toppings that were themselves once considered a meal; crazed sports fans demolishing plates of radioactively hot wings; barbecued or bacon-wrapped . . . anything. But there is much more to the phenomenon of dude food than what’s on the plate. Emily J. H. Contois’s provocative book begins with the dude himself—a man who retains a degree of masculine privilege but doesn’t meet traditional standards of economic and social success or manly self-control. In the Great Recession’s aftermath, dude masculinity collided with food producers and marketers desperate to find new customers. The result was a wave of new diet sodas and yogurts marketed with dude-friendly stereotypes, a transformation of food media, and weight loss programs just for guys. In a work brimming with fresh insights about contemporary American food media and culture, Contois shows how the gendered world of food production and consumption has influenced the way we eat and how food itself is central to the contest over our identities.
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Hunzeker, Michael A. Dying to Learn. Cornell University Press, 2021. http://dx.doi.org/10.7591/cornell/9781501758454.001.0001.
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This book develops a novel theory to explain how wartime militaries learn. It focuses on the Western Front, which witnessed three great-power armies struggle to cope with deadlock throughout the First World War, as the British, French, and German armies all pursued the same solutions-assault tactics, combined-arms, and elastic defense in depth. By the end of the war, only the German army managed to develop and implement a set of revolutionary offensive, defensive, and combined-arms doctrines that in hindsight represented the best way to fight. The book identifies three organizational variables that determine how fighting militaries generate new ideas, distinguish good ones from bad ones, and implement the best of them across the entire organization. These factors are: the degree to which leadership delegates authority on the battlefield; how effectively the organization retains control over soldier and officer training; and whether or not the military possesses an independent doctrinal assessment mechanism. Through careful study of the British, French, and German experiences in the First World War, the book provides a model that shows how a resolute focus on analysis, command, and training can help prepare modern militaries for adapting amidst high-intensity warfare in an age of revolutionary technological change.
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Ruth, Greg. Tennis. University of Illinois Press, 2021. http://dx.doi.org/10.5622/illinois/9780252043895.001.0001.
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This book reassess how tennis evolved from a cloistered amateur game to a more inclusive and thoroughly professionalized global sport. Tennis began in Britain in 1873. The game grew quickly along the east coast of the United States before moving west, where it found a home in California. For most of its history, tennis remained a sport that separated amateur and professional players. In the minds of the private clubs and associations that organized the game for the first half century of its existence, control rather than commercialization was paramount. The Great Depression and World War II significantly undermined the authority of those associations by introducing a new generation of less affluent and working-class players with social backgrounds different than those of the men who ran the amateur associations. The best of those athletes challenged the amateur associations about the role of money in their sport. From 1945 to 1968, they professionalized tennis with annual barnstorming tours throughout the world. The visibility, viability, and popularity of those tours finally coaxed the reluctant leaders of amateur associations to allow the opening of their major tournament venues to professional players in 1968. Almost simultaneously, sports marketers, professional promoters, and sports publishers popularized and further globalized so-called Open Tennis into much the same form it retains today.
Book chapters on the topic "Contrôle à retards"
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Colonius, Fritz. "Retarded functional differential equations." In Optimal Periodic Control, 31–47. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/bfb0077934.
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Gershon, Eli, and Uri Shaked. "Static Output-Feedback Control of Retarded Stochastic Systems." In Advances in H∞ Control Theory, 187–203. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-16008-1_13.
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Tran, Hien T. "Numerical Studies of the Linear Quadratic Control Problem for Retarded Systems with Delay in Control." In Computation and Control II, 307–24. Boston, MA: Birkhäuser Boston, 1991. http://dx.doi.org/10.1007/978-1-4612-0427-5_21.
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Gómez, J. A. "Optimal control of non linear retarded systems with phase constraints." In Lecture Notes in Mathematics, 264–73. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/bfb0089603.
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Gershon, Eli, and Uri Shaked. "H ∞ Control and Estimation of Retarded Linear Discrete-Time Systems." In Advanced Topics in Control and Estimation of State-Multiplicative Noisy Systems, 95–113. London: Springer London, 2013. http://dx.doi.org/10.1007/978-1-4471-5070-1_5.
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Germani, Alfredo, Costanzo Manes, and Pierdomenico Pepe. "Observer-Based Stabilizing Control for a Class of Nonlinear Retarded Systems." In Time Delay Systems: Methods, Applications and New Trends, 331–42. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-25221-1_25.
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Mo, Xixian, Feng Jiang, Wenhui Wang, Bo Zhang, and Ye Ding. "Control of a Mechanically Compliant Joint with Proportional-Integral-Retarded (PIR) Controller." In Intelligent Robotics and Applications, 379–90. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-97586-3_34.
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Papageorgiou, D. T., C. Maldarelli, and Y. Wang. "Mobility Control of Surfactant-Retarded Bubbles at Small and Order One Reynolds Numbers." In Fluid Mechanics and Its Applications, 175–84. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-017-1996-4_16.
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Pepe, P. "Lyapunov-Razumikhin Methods for Stabilization in the Sample-and-Hold Sense of Retarded Nonlinear Systems." In 2015 Proceedings of the Conference on Control and its Applications, 197–204. Philadelphia, PA: Society for Industrial and Applied Mathematics, 2015. http://dx.doi.org/10.1137/1.9781611974072.28.
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Park, Ju H., Hao Shen, Xiao-Heng Chang, and Tae H. Lee. "Reliable Event-Triggered Retarded Dynamic Output Feedback $$\mathscr {H}_{\infty }$$H∞ Control for Networked Systems." In Recent Advances in Control and Filtering of Dynamic Systems with Constrained Signals, 85–100. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-96202-3_5.
Full textConference papers on the topic "Contrôle à retards"
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Samouei, Hamidreza, Igor Ivanishin, and Abdollah Orangi. "Novel Class of Retarded, Newtonian, Single-Phase HCl-Based Stimulation Fluids: A Laboratory Characterization." In SPE International Conference and Exhibition on Formation Damage Control. SPE, 2022. http://dx.doi.org/10.2118/208813-ms.
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Abstract Novel retarded acids were designed and evaluated by measuring their dissolution and corrosion rates in the laboratory at a temperature of 250°F. Results indicate that depending on the type of the retarder, the acid solutions containing 15 wt% HCl react 1.2–10.7 slower than 15 wt% straight HCl. In addition, novel retarded acids pass the industry standard for corrosion rate of L80, P110, T95, and 13Cr steel grades even with no corrosion inhibitor added to the formulation. Field application of the novel acid systems will provide a series of benefits, including ease to mix and pump, operational safety, deep stimulation of target zone, etc. Presented results are integral for designing the stimulation operations in carbonate reservoirs and the removal of carbonate scales in the oil and gas or geothermal energy industries.
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Suryawanshi, J. G., and N. V. Deshpande. "The Effects of Combination of EGR, Injection Retard and Injection Pressure on Emissions and Performance of Diesel Engine Fuelled With Jatropha Oil Methyl Ester." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13021.
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Retarded injection is used to control NOx emissions. Exhaust Gas Recirculation (EGR) is also an effective means of reducing NOx emissions from compression ignition engines. Higher fuel injection pressure may improve the combustion. EGR can be combined advantageously with other emission reducing measure such as retarded injection timing and performance improvement measures such as higher fuel injection pressure to have a good effect. The methyl ester of jatropha oil, known as biodiesel, is receiving increasing attention as an alternative fuel for diesel engines. Biodiesel is a non-toxic, biodegradable and renewable fuel with the potential to reduce engine exhaust emissions. The jatropha oil methyl ester was obtained through transesterification process. Various properties of the biodiesel thus developed were evaluated and compared in relation to that of conventional diesel oil. In the present investigation neat jatropha oil methyl ester (JME) as well as the blends of varying proportions of JME and diesel were used to run a CI engine with standard conditions (No EGR, No Injection Retard and 20 MPa Fuel Injection Pressure) and with combination of 20 % EGR, 4° retarded injection timing and 30 MPa fuel injection pressure. The addition of jatropha oil methyl ester (JME) to diesel fuel has significantly reduced HC, CO and smoke emissions but it increases the NOx emissions slightly with standard conditions. The NOx emission was drastically decreased with modified conditions. Further the smoke and unburned hydrocarbon emissions were decreased with modified conditions as compared to standard conditions. The brake thermal efficiency was improved with modified conditions at various loads. Exhaust gas temperatures were similar. The maximum cylinder gas pressure and heat release rate were lowered.
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Mirzaei, Saeid, and Antonio Fernandez. "Retard system solution on electric mining trucks." In 2012 IEEE Symposium on Sensorless Control for Electrical Drives (SLED). IEEE, 2012. http://dx.doi.org/10.1109/sled.2012.6422816.
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Qing Hui. "Semistability of retarded functional differential equations." In 2011 American Control Conference. IEEE, 2011. http://dx.doi.org/10.1109/acc.2011.5991174.
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Kimbrough, Scott. "Optimal Control of Electromagnetic Brake Retarders." In International Truck & Bus Meeting & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1994. http://dx.doi.org/10.4271/942325.
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Kowalewski, A. "Distributed control of a retarded hyperbolic system." In 1999 European Control Conference (ECC). IEEE, 1999. http://dx.doi.org/10.23919/ecc.1999.7099410.
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Hornburg, Kathryn J., Ravi K. Komanduri, and Michael J. Escuti. "Multiband retardation control using multi-twist retarders." In SPIE Sensing Technology + Applications, edited by David B. Chenault and Dennis H. Goldstein. SPIE, 2014. http://dx.doi.org/10.1117/12.2051170.
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Chen, Xiuqi, Wei Wei, Tangzhu Liu, Wenhao Xie, Yifei Li, Wang Zhuo, Wang Ruolin, and Qindong Yan. "Proper Orthogonal Decomposition Analysis and Braking Control on Hydrodynamic Retarders by Bionic Iris Effective Diameter Regulation." In ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-60208.
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Abstract AIris, a flat circular membrane in the middle layer of human eyeball, is controlled by sympathetic nerve and can automatically adjust pupil size according to light intensity to limit the amount of light entering the eyeball. This paper attempts to introduce the artificial iris diameter changing mechanism into hydrodynamic machinery, that is, to control the hydrodynamic retarder without filling fluid by changing the inner diameter of iris and changing the flow path of retarder. Through the decomposition and reconstruction of the intrinsic flow field, the flow field characteristics of the iris retarder are deeply understood, and the fast prediction of the braking torque is realized. At the same time, the close-loop controller is designed to control the iris opening that realizing the adaptive adjustment of the output torque of the retarder, thus overcoming the difficulty on-line observation of actual filling rate of oil problem and the inaccurate tracking of braking torque on traditional hydrodynamic retarder with filling rate control. Our work prove that the nonlinear controller can achieve fast and accurate torque closed-loop torque control in various braking conditions compared with the hydrodynamic rate control retarder, and the potential of iris mechanism for adaptive control of hydrodynamic retarder is verified.
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Daeffler, Christopher, Julia Fernandez del Valle, Jean Elkhoury, Mohan Panga, Max Nikolaev, and Bulat Kamaletdinov. "Dolomite Stimulation with Retarded Acids." In SPE International Conference on Oilfield Chemistry. SPE, 2021. http://dx.doi.org/10.2118/204386-ms.
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Abstract Globally, dolomite formations are important reservoirs for oil and gas. Acid stimulation is commonly used to extend the life of carbonate reservoirs, and a good understanding of the fluid performance is essential for effective treatment design. Three acids, hydrochloric acid (HCl), emulsified HCl, and a single-phase retarded acid based on HCl, were assessed for their ability to create wormholes in Silurian dolomite under laboratory conditions using a standard core flow experiment. Select cores were imaged by X-ray computed tomography to visualize the wormhole morphology. Similar experiments in Indiana limestone was used as a control. The core flow experiments showed that the pore volume to break-through (PVbt) values for the retarded acids in Indiana limestone were less sensitive to changes in temperature overall than unmodified HCl. For Silurian dolomite though, the opposite is observed. HCl has uniformly high PVbt values at lower (200 °F) and higher (325 °F). The emulsified acid and the single-phase retarded acid are more efficient than HCl, but the difference is smaller at 325 °F. Core images revealed that all three fluids had some degree of wormhole branching at 200 °F and much less branching at 325 °F. By visual inspection, the single-phase retarded acid has less ramification than HCl and the emulsified acid. Overall, the results show that retarded acids should make effective stimulation fluids for dolomite reservoirs.
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Villafuerte, R., S. Mondie, C. Vazquez, and J. Collado. "Proportional retarded control of a second order system." In 2009 6th International Conference on Electrical Engineering, Computing Science and Automatic Control (CCE 2009). IEEE, 2009. http://dx.doi.org/10.1109/iceee.2009.5393441.
Full textReports on the topic "Contrôle à retards"
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Bramlage, William, Nehemia Aharoni, Wassef W. Nawar, Joseph Kanner, Shimon Meir, and Sonia Philosoph-Hadas. Control of Lipid Oxidation to Retard Senescence of Plant Tissue. United States Department of Agriculture, May 1994. http://dx.doi.org/10.32747/1994.7603823.bard.
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Aharoni, Nehemia, and Shang Fa Yang. Control of Ethylene Biosynthesis and Action to Retard the Senescence of Harvested Vegetables. United States Department of Agriculture, April 1986. http://dx.doi.org/10.32747/1986.7566572.bard.
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David, Aharon. Unsettled Topics Concerning Airport Cybersecurity Standards and Regulation. SAE International, September 2021. http://dx.doi.org/10.4271/epr2021020.
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A large international airport is a microcosm of the entire aviation sector, hosting hundreds of different types of aviation and non-aviation stakeholders: aircraft, passengers, airlines, travel agencies, air traffic management and control, retails shops, runway systems, building management, ground transportation, and much more. Their associated information technology and cyber physical systems—along with an exponentially resultant number of interconnections—present a massive cybersecurity challenge. Unlike the physical security challenge, which was treated in earnest throughout the last decades, cyber-attacks on airports keep coming, but most airport lack essential means to confront such cyber-attacks. These missing means are not technical tools, but rather holistic regulatory directives, technical and process standards, guides, and best practices for airports cybersecurity—even airport cybersecurity concepts and basic definitions are missing in certain cases. Unsettled Topics Concerning Airport Cybersecurity Standards and Regulation offers a deeper analysis of these issues and their causes, focusing on the unique characteristics of airports in general, specific cybersecurity challenges, missing definitions, and conceptual infrastructure for the standardization and regulation of airports cybersecurity. This last item includes the gaps and challenges in the existing guides, best-practices, standards, and regulation pertaining to airport cybersecurity. Finally, practical solution-seeking processes are proposed, as well as some specific potential frameworks and solutions.
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Manulis, Shulamit, Christine D. Smart, Isaac Barash, Guido Sessa, and Harvey C. Hoch. Molecular Interactions of Clavibacter michiganensis subsp. michiganensis with Tomato. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7697113.bard.
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Clavibacter michiganensis subsp. michiganensis (Cmm), the causal agent of bacterial wilt and canker of tomato, is the most destructive bacterial disease of tomato causing substantial economic losses in Israel, the U.S.A. and worldwide. The molecular strategies that allow Cmm, a Gram-positive bacterium, to develop a successful infection in tomato plants are largely unknown. The goal of the project was to elucidate the molecular interactions between Cmmand tomato. The first objective was to analyze gene expression profiles of susceptible tomato plants infected with pathogenic and endophytic Cmmstrains. Microarray analysis identified 122 genes that were differentially expressed during early stages of infection. Cmm activated typical basal defense responses in the host including induction of defense-related genes, production of scavenging of free oxygen radicals, enhanced protein turnover and hormone synthesis. Proteomic investigation of the Cmm-tomato interaction was performed with Multi-Dimensional Protein Identification Technology (MudPIT) and mass spectroscopy. A wide range of enzymes secreted by Cmm382, including cell-wall degrading enzymes and a large group of serine proteases from different families were identified in the xylem sap of infected tomato. Based on proteomic results, the expression pattern of selected bacterial virulence genes and plant defense genes were examined by qRT-PCR. Expression of the plasmid-borne cellulase (celA), serine protease (pat-1) and serine proteases residing on the chp/tomA pathogenicity island (chpCandppaA), were significantly induced within 96 hr after inoculation. Transcription of chromosomal genes involved in cell wall degradation (i.e., pelA1, celB, xysA and xysB) was also induced in early infection stages. The second objective was to identify by VIGS technology host genes affecting Cmm multiplication and appearance of disease symptoms in plant. VIGS screening showed that out of 160 tomato genes, which could be involved in defense-related signaling, suppression of 14 genes led to increase host susceptibility. Noteworthy are the genes Snakin-2 (inhibitor of Cmm growth) and extensin-like protein (ELP) involved in cell wall fortification. To further test the significance of Snakin -2 and ELP in resistance towards Cmm, transgenic tomato plants over-expressing the two genes were generated. These plants showed partial resistance to Cmm resulting in a significant delay of the wilt symptoms and reduction in size of canker lesion compared to control. Furthermore, colonization of the transgenic plants was significantly lower. The third objective was to assess the involvement of ethylene (ET), jasmonate (JA) and salicylic acid (SA) in Cmm infection. Microarray and proteomic studies showed the induction of enzymes involved in ET and JA biosynthesis. Cmm promoted ET production 8 days after inoculation and SIACO, a key enzyme of ET biosynthesis, was upregulated. Inoculation of the tomato mutants Never ripe (Nr) impaired in ET perception and transgenic plants with reduced ET synthesis significantly delayed wilt symptoms as compared to the wild-type plants. The retarded wilting in Nr plants was shown to be a specific effect of ET insensitivity and was not due to altered expression of defense related genes, reduced bacterial population or decrease in ethylene biosynthesis . In contrast, infection of various tomato mutants impaired in JA biosynthesis (e.g., def1, acx1) and JA insensitive mutant (jai1) yielded unequivocal results. The fourth objective was to determine the role of cell wall degrading enzymes produced by Cmm in xylem colonization and symptoms development. A significance increase (2 to 7 fold) in expression of cellulases (CelA, CelB), pectate lyases (PelA1, PelA2), polygalacturonase and xylanases (XylA, XylB) was detected by qRT-PCR and by proteomic analysis of the xylem sap. However, with the exception of CelA, whose inactivation led to reduced wilt symptoms, inactivation of any of the other cell wall degrading enzymes did not lead to reduced virulence. Results achieved emphasized the complexity involved in Cmm-tomato interactions. Nevertheless they provide the basis for additional research which will unravel the mechanism of Cmm pathogenicity and formulating disease control measures.
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In-depth survey report: the control of methylene chloride in furniture stripping at Association for Retarded Citizens, Washington County Chapter, Inc., Meadow Lands, Pennsylvania. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, March 1991. http://dx.doi.org/10.26616/nioshectb17018a.
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