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Yu, Heng. "On Decoupling Concurrency Control from Recovery in Database Repositories". Thesis, University of Waterloo, 2005. http://hdl.handle.net/10012/1084.
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We report on initial research on the concurrency control issue of compiled database applications. Such applications have a repository style of architecture in which a collection of software modules operate on a common database in terms of a set of predefined transaction types, an architectural view that is useful for the deployment of database technology to embedded control programs. We focus on decoupling concurrency control from any functionality relating to recovery. Such decoupling facilitates the compile-time query optimization. Because it is the possibility of transaction aborts for deadlock resolution that makes the recovery subsystem necessary, we choose the deadlock-free tree locking (TL) scheme for our purpose. With the knowledge of transaction workload, efficacious lock trees for runtime control can be determined at compile-time. We have designed compile-time algorithms to generate the lock tree and other relevant data structures, and runtime locking/unlocking algorithms based on such structures. We have further explored how to insert the lock steps into the transaction types at compile time.
To conduct our simulation experiments to evaluate the performance of TL, we have designed two workloads. The first one is from the OLTP benchmark TPC-C. The second is from the open-source operating system MINIX. Our experimental results show TL produces better throughput than the traditional two-phase locking (2PL) when the transactions are write-only; and for main-memory data, TL performs comparably to 2PL even in workloads with many reads.
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Katabi, Dina 1971. "Decoupling congestion control and bandwidth allocation policy with application to high bandwidth-delay product networks". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/8000.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.Includes bibliographical references (p. 124-129).
In this dissertation, we propose a new architecture for Internet congestion control that decouples the control of congestion from the bandwidth allocation policy. We show that the new protocol, called XCP, enables very large per-flow throughput (e.g., more than 1 Gb/s), which is unachievable using current congestion control. Additionally, we show via extensive simulations that XCP significantly improves the overall performance, reducing drop rate by three orders of magnitude, increasing utilization, decreasing queuing delay, and attaining fairness in a few RTTs. Using tools from control theory, we model XCP and demonstrate that, in steady state, it is stable for any capacity, delay, and number of sources. XCP does not maintain any per-flow state in routers and requires only a few CPU cycles per packet making it implementable in high-speed routers. Its flexible architecture facilitates the design and implementation of quality of service, such as guaranteed and proportional bandwidth allocations. Finally, XCP is amenable to gradual deployment.
by Dina Katabi.
Ph.D.
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Antony, Geo Johns. "Cheops reloaded, further steps in decoupling geo-distribution from application business logic : a focus on externalised sharding collaboration, consistency and dependency". Electronic Thesis or Diss., Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2024. http://www.theses.fr/2024IMTA0441.
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La transition du cloud computing centralisé vers des applications géo-distribuées est essentielle pour répondre aux exigences modernes de services à faible latence, haute disponibilité et résilience. Cependant, les solutions existantes de géo-distribution nécessitent souvent des modifications intrusives du code de l’application. Ma thèse étend Cheops, un middleware qui découple la géo-distribution de la logique applicative, offrant une solution non intrusive et générique pour déployer une application sur des instances géographiquement distribuées. S’appuyant sur les principes de Cheops, "local-first" et "collaborative-then", mes recherches introduisent Cross, un mécanisme de collaboration par fragmentation pour partitionner les ressources entre différents sites, ainsi qu’une nouvelle approche pour découplerla gestion de la cohérence de la logique applicative, garantissant la synchronisation entre les instances. De plus, la gestion des dépendances assure que les opérations effectuées sur une instance sont reproductibles à travers les instances géo-distribuées, maintenant l’illusion d’une application unifiée et localisée sur un seul site. Cheops utilise Scope-lang, un langage spécifique au domaine (DSL), pour faciliter cela sans modifier la logique de l’application. Cette extension de Cheops renforce davantage la séparation entre la géo-distribution et la logique métier de l’applicationThe shift from centralized cloud computing to geo-distributed applications is critical for meeting modern demands for low-latency, highly available, and resilient services. However, existing geo-distribution solutions often require intrusive modifications to application code. My thesis extends the Cheops framework, a middleware that decouples geodistribution from application logic, offering a non-intrusive and generic solution for deploying an application across geographically distributed instances. Building on the Cheops principles of "local-first" and "collaborative-then," my research introduces Cross, a shard collaboration mechanism for partitioning resources across sites, and a new approach to decoupling consistency from the application logic, ensuring synchronization between instances. Additionally, dependency management guarantees that operations performed on one instance are reproducible across geo-distributed instances, maintaining the illusion of a unified, singlesite application. Cheops uses Scope-lang, a Domain-Specific Language (DSL), to facilitate this without altering application logic. This extension of Cheops, further enhances the separation of geo-distribution from the application business logic
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Vitali, Vito. "Monte Carlo analysis of heterogeneity and core decoupling effects on reactor kinetics : Application to the EOLE critical facility". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP045.
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L'analyse de la cinétique du réacteur est un élément clé pour la caractérisation du comportement non-stationnaire de la population neutronique lors de transitoires opérationnels ou accidentels. La dérivation des équations de la cinétique ponctuelle est intrinsèquement fondée sur le collapse de l'espace de phases associé à l'équation de Boltzmann (décrivant le transport des neutrons) en quelques paramètres efficaces permettant de représenter le réacteur comme un "point" , pourvu que la population neutronique obéisse au mode propre fondamental. La cinétique ponctuelle est très largement adoptée dans la communauté de la physique des réacteurs en tant qu'outil fiable et rapide pour l'analyse de la cinétique des cœurs. Toutefois, il est connu que l'utilisation des équations de la cinétique ponctuelle est pertinente seulement si le cœur est suffisamment homogène (pour que le collapse en un point soit une approximation raisonnable) et si le mode propre fondamental est suffisamment séparé des harmoniques supérieures (pour que la réduction au mode fondamental soit bien posée). L'objectif de cette thèse est de maitriser l'impact de la géométrie et des compositions matérielles du cœur sur la cinétique, en vue de la possibilité d'interpréter des données issues de l'expérience EPILOGUE (qui sera réalisée dans la maquette EOLE du CEA/Cadarache). A cette fin, une analyse spectrale par méthodes de Monte Carlo sera mise en place dans le code TRIPOLI-4 développé au SERMA, pour déterminer la séparation des modes propres et des valeurs propres du réacteur en fonction des caractéristiques du cœurThe analysis of the reactor core kinetics is key for the characterization of the non-stationary neutron population behavior during operational or accidental transients. Point-kinetics equations, whose derivation is intrinsically based on collapsing the full phase space of the Boltzmann equation into a few effective parameters (representing the whole reactor as a "point", provided that the entire neutron population obeys the fundamental eigen-mode), are widely used in the reactor physics community as a reliable and fast tool for the analysis of core kinetics. However, their use is deemed to be appropriate only when the core is sufficiently homogeneous (for the collapsing to a point to be a realistic approximation), and when the fundamental mode of the neutron population is sufficiently separated from higher harmonics (for the reduction to the fundamental mode to be meaningful). The goal of this thesis is to investigate the impact of system geometry and material compositions on the reactor kinetics, via an eigen- mode decomposition, in view of interpreting experimental data coming from the EPILOGUE experiments carried out at the EOLE critical facility (CEA/Cadarache). To this aim, spectral analysis techniques based on Monte Carlo methods will be implemented in the Monte Carlo code TRIPOLI-4 (developed at SERMA), so as to determine the separation between reactor eigen-modes and eigen-values as a function of the core features
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Le, Brun Christophe. "Analyse et commande de systèmes multivariables. Application à un turbopropulseur". Thesis, CentraleSupélec, 2015. http://www.theses.fr/2015SUPL0012.
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Les travaux entrepris au cours de cette thèse ont permis de concevoir des stratégies de commande de systèmes multivariables (outils d’analyse et méthodes de synthèse) en vue de leur application au développement de lois de commande d’un turbopropulseur.D’un point de vue fonctionnel, un turbopropulseur est un système multivariable comprenant deux grandeurs de commande : le débit carburant à injecter dans la chambre de combustion et le pas de l’hélice, ainsi que deux grandeurs de sortie : la puissance délivrée par l’hélice et sa vitesse de rotation. Ces variables sont fortement couplées, ce qui signifie que des variations de l’une entraînent des écarts sur l’autre. L’objectif de ces travaux est de synthétiser des lois de commande facilement ajustables, permettant de respecter des spécifications classiques en Automatique (temps de réponse, dépassement, erreur statique) et de réduire les couplages entre les différentes grandeurs régulées. Dans ce contexte industriel, les approches décentralisées sans et avec découplage sont envisagées. La stratégie décentralisée pure met en œuvre un correcteur diagonal, ce qui revient à asservir un système par plusieurs boucles monovariables indépendantes. Bien que relativement facile à synthétiser et à implanter, la stratégie décentralisée ne permet pas d’atteindre les performances souhaitées en présence d’interactions importantes. Dans ce cas, il est possible de l’associer à des compensateurs permettant de diminuer les interactions.Une part importante de ces travaux de recherche concerne le développement méthodologique de ces stratégies. La définition d’une stratégie de commande est la première étape. Pour cela, la quantification du niveau d’interaction dans un système se révèle importante. Celle-ci peut être réalisée à l’aide de différentes méthodes et indicateurs qui s’appuient sur les réponses fréquentielles ou temporelles du système, ou encore sur les grammiens de commandabilité et d’observabilité. Une procédure systématique d’analyse des interactions a été proposée afin de déterminer la stratégie de commande la plus adaptée en fonction des interactions. Dans le cas où l’analyse des interactions conduit à adopter une stratégie décentralisée, les régulateurs peuvent être synthétisés à l’aide de méthodes monoboucles ou multiboucles. Les premières ne prennent pas en compte les interactions tandis que les secondes, plus élaborées mais également plus complexes à mettre en œuvre, permettent de les prendre spécifiquement en compte. A la suite de l’analyse de ces méthodes, une étude récapitulative présentant les méthodes préconisées en fonction du procédé et des objectifs, est finalement proposée. Dans le cas où l’analyse des interactions montre un niveau de couplage trop important, il est possible d’associer des compensateurs à la régulation décentralisée. Les compensateurs ont pour but de découpler les commandes vis-à-vis des sorties du procédé. Différentes méthodes et structures de découplage ont été étudiées et comparées. Une procédure de découplage, composée des méthodes considérées comme les plus efficaces a finalement été mise en placeIn this Ph.D. thesis, we explore the different steps of designing a decentralized control applied on a turboprop engine.From the control point of view, the turboprop engine is a TITO (Two-Input Two-Output) process. The fuel flow is used to control the shaft power while the blade pitch angle is used to control the propeller speed. The turboprop presents important couplings between manipulated variables and controlled variables. When the fuel flow changes, the propeller speed is impacted. Similarly, when controlling the blade pitch angle to change the propeller speed to another level, the shaft power is affected, particularly during the transient states. The main objective of this research thesis is to design control laws for the turboprop. Beside technical specifications like response time and overshoot, couplings between loops have to be reduced as much as possible and control laws have to be robust to model uncertainties. For this industrial environment a decentralized strategy (with or without compensators) has been chosen. The decentralized strategy consists in designing monoloop controllers in order to drive the multivariable system. The decentralized strategy presents important benefits, such as flexibility as well as design simplicity, but is not efficient in presence of heavy couplings. In that case, it is possible to use compensators that reduce existing process interactions before designing the monoloop controllers.An important part of this work focuses on the development of these different strategies.The first step is the choice of the control structure, which strongly depends on the level of interaction. Despite the availability of different metrics - based on frequential responses, temporal responses, or Gramian – it is not easy to know which one is the most appropriate. Based on the analysis of couplings with different metrics, a procedure is proposed in order to choose the structure and the controllers design method.If the coupling analysis leads to adopt a decentralized strategy, the controllers can be designed using monoloop or multiloop methods. The first ones are simple but do not take couplings into account, whereas multiloop methods take specifically couplings into account but are more complicated. These tuning methods have been studied and recommendations have finally been made to choose the most appropriated method depending on the process and the requirements.In cases where the couplings analysis reveals a high couplings level, compensators can be associated with the decentralized strategy. The objectives of the compensators are to reduce couplings in the system and to facilitate the design of monoloop controllers. Several decoupling structures have been studied and compared. A decoupling procedure has then been proposed.These methodological studies have been applied to the turboprop engine. Following the coupling analysis, a decentralized strategy with decoupling has been chosen. After following the decoupling procedure and trying different solutions, the inverted decoupler has been adopted. Considering the dynamics of the system and the total decoupling provided by the inverted decoupler, PI controllers have been used and a monoloop tuning method has been chosen. In order to guarantee the desired performances over the whole flight envelope, control laws have been interpolated, using a gain scheduling technique. The structured singular value approach has then been used to demonstrate the robustness of the control laws with model uncertainties. Control laws have finally been implemented in the control software and simulation results have illustrated their good performances
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Heiland, Jan [Verfasser], Volker [Akademischer Betreuer] Mehrmann, Michael [Akademischer Betreuer] Hinze i Tomás [Akademischer Betreuer] Roubicek. "Decoupling and optimization of differential-algebraic equations with application in flow control / Jan Heiland. Gutachter: Michael Hinze ; Volker Mehrmann ; Tomas Roubicek. Betreuer: Volker Mehrmann". Berlin : Technische Universität Berlin, 2014. http://d-nb.info/1067386157/34.
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Yang, Jiaming. "Melting in the Mantle Wedge: Quantifying the Effects of Crustal Morphology and Viscous Decoupling on Melt Production with Application to the Cascadia Subduction Zone". PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/3880.
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Arc magmatism is sustained by the complex interactions between the subducting slab, the overriding plate, and the mantle wedge. Partial melting of mantle peridotite is achieved by fluid-induced flux melting and decompression melting due to upward flow. The distribution of melting is sensitive to temperature, the pattern of flow, and the pressure in the mantle wedge. The arc front is the surface manifestation of partial melting in the mantle wedge and is characterized by a narrow chain of active volcanoes that migrate in time. The conventional interpretation is that changes in slab dip angle lead to changes in the arc front position relative to the trench. We explore an alternative hypothesis: evolution of the overlying plate, specifically thickening of the arc root, causes arc front migration. We investigate the effects of varying crustal morphology and viscous decoupling of the shallow slab-mantle interface on melt production using 2D numerical models involving a stationary overriding plate, a subducting plate with prescribed motion, and a dynamic mantle wedge. Melt production is quantified using a hydrous melting parameterization. We conclude: 1) Localized lithospheric thickening shifts the locus of melt production trenchward while thinning shifts melting landward. 2) Inclined LAB topography modulates the asthenospheric flow field, producing a narrow, well-defined arc front. 3) Thickening of the overriding plate exerts increased torque on the slab, favoring shallowing of the dip angle. 4) Viscous decoupling produces a cold, stagnant forearc mantle but promotes arc front melting due to reduction in the radius of corner flow, leading to higher temperatures at the coupling/decoupling transition.
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Sifi, Mohcine. "Diagnostic à base de modèles non linéaires. : Application au circuit carburant d'une turbomachine". Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0054/document.
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Les systèmes de régulation des turbomoteurs actuels sont basés sur des architectures complexes que les constructeurs tendent à rendre plus modulaires avec des technologies plus économiques tout en garantissant un niveau de fiabilité supérieur ou égal. Dans ce contexte, la surveillance du circuit carburant, qui a pour but de déceler les dysfonctionnements des composants hydrauliques critiques, permet de réduire le coût de maintenance, d'améliorer le niveau de maintenabilité et d'assurer la disponibilité des turbomoteurs. La présente étude porte sur l'élaboration de méthodes de diagnostic performantes et robustes permettant la détection et la localisation des défauts impactant les fonctions hydrauliques primaires du circuit carburant. Des méthodes existantes de génération de résidus à base de modèles non linéaires sont présentées et appliquées au cas du circuit carburant. L'approche analytique pour le découplage, combinée avec des filtres de Kalman étendus, permet la structuration des résidus pour assurer la localisation des défauts. Une nouvelle approche basée sur la théorie de platitude différentielle est proposée pour le diagnostic de défauts des systèmes non linéaires avec une application au cas du circuit carburant. Les différentiateurs à modes glissants sont utilisés pour l'estimation des dérivées de signaux nécessaires à l'application de certaines méthodes de génération de résidus. Des simulations numériques illustrent la pertinence des résultats obtenus. Une application expérimentale est présentée en utilisant un jeu de données réelles issues d'un banc d'essais partiel et fournies par la société Turbomeca du groupe SAFRANThe current gas turbine regulation systems are based on complex architectures that manufacturers tend to make more modular with more cost effective technologies while ensuring a greater or equal level of reliability. In this context, the fuel system health monitoring, which aims to identify critical hydraulic components dysfunction, allows to reduce maintenance costs, to improve maintainability level and to ensure gas turbine availability. The present study focuses on the development of performant and robust diagnosis methods for the detection and isolation of faults affecting primary fuel system hydraulic functions. Existing nonlinear model based residual generation methods are presented and applied to the fuel system. The analytical approach for decoupling, combined with extended Kalman filters, helps fault isolation by generating residual structures. A new approach based on differential flatness theory is proposed for nonlinear systems fault diagnosis with an application to the fuel system. Sliding mode differentiators are used to estimate derived signals that are necessary for the application of some residual generation methods. Numerical simulations illustrate the efficiency of obtained results. An experimental application is presented using a real data set from a partial test bench provided by Turbomeca company of the SAFRAN group
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Délémontey, Bertrand. "Contribution à la commande des entraînements asynchrones de forte puissance : application au problème de traction". Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL154N.
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L’objectif de ce travail est l'étude de la commande découplée du flux et du couple pour des machines asynchrones de forte puissance. Celle-ci concerne l'ensemble alimentation-machine-charge. Des problèmes spécifiques apparaissent dus à la forte puissance et à la configuration de l'alimentation: découplage flux-couple, instabilité de la chaîne complète. Notre travail porte tout d'abord sur l'étude théorique de la commande découplée du flux et du couple: un découplage prenant en compte les constantes de temps naturelles du moteur a été obtenu. Puis, après avoir mis en évidence de manière théorique les problèmes d'instabilité constatés expérimentalement, nous montrons que l'on ne peut à la fois assurer le découplage couple/flux et la stabilisation. Une solution de compromis a été trouvée par une technique de stabilisation prenant en compte le filtre d'entrée. Diverses commandes lui ont été associées dont une commande de type H2, assurant des résultats satisfaisants sur toute la plage de vitesse ou cette commande peut être mise en œuvre. L’ensemble de la commande a été implanté sur une carte industrielle et testé expérimentalement sur un banc de 300 kW. Cette étude a été réalisée en collaboration avec la société GEC ALSTHOM TRANSPORT dans le cadre général de la conception de chaines de traction asynchrone pour le TGV de nouvelle génération
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Oke, Adetola. "Disturbance Decoupling Problem for Discrete-Event Systems with Applications". Thesis, Southern Illinois University at Edwardsville, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10127217.
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This thesis presents the new investigations on the disturbance decoupling problem (DDP) for the geometric control of max-plus linear systems, which are used to model discrete event systems such as transportation networks, queuing systems, and communication networks. The classical DDP concept in the geometric control theory means that the controlled outputs will not be changed by any disturbances. In practical manufacturing systems, solving for the DDP would require further delays on the output parts than the existing delays caused by the system breakdown, which will be less practical in real applications. The new proposed modified disturbance decoupling problem (MDDP) in this thesis ensures that the controlled output signals will not be delayed more than the existing delays caused by the disturbances in order to achieve the just-in-time optimal control. Furthermore, this thesis presents the integration of output feedback and open-loop control strategies to solve for the MDDP, as well as for the DDP. The main results of this thesis are illustrated by using timed event graph models of a high throughput screening system in drug discovery and a railway transport network.
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Feuillet, Thomas. "Développement de capteurs optimisés pour l'IRM à champ magnétique faible (0.2T) : application à l'imagerie de l'animal". Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10302/document.
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L'imagerie par résonance magnétique (IRM) appliquée au domaine vétérinaire exploite des systèmes à bas champ magnétostatique qui ont de nombreux avantages, notamment leur faible coût d'achat et d'entretien. Mais sur ces machines, les capteurs radiofréquence (RF) sont initialement dédiées à l'homme et ne permettent pas une qualité d'image optimale. Dans le cadre de cette thèse, des méthodes simples d'optimisation de capteurs à 0,2 T ont été développées, puis exploitées pour des applications de recherche et préclinique. Le travail d'optimisation a été partagé en deux axes. Dans un premier temps, un modèle analytique a été développé sous MATLAB pour l'estimation du rapport signal sur bruit intrinsèque à un capteur paramétré par ses dimensions et les propriétés de l'objet imagé. La validation du modèle a été obtenue par la comparaison entre mesures et simulations du facteur de qualité. Cette méthode d'optimisation a été appliquée pour deux études spécifiques qui ont fait l'objet d'une publication. Dans un second temps, un travail sur le découplage actif a été mené. En effet, sur l'IRM 0,2 T à notre disposition, le découplage passif est la méthode retenue par le constructeur. Mais pour certaines applications des artefacts d'imagerie sont inévitables et le facteur de qualité réduit. Des moyens de découplage actif ont donc été développés. Les performances des capteurs ainsi équipés se sont avérées meilleures qu'en découplage passif. Ce système de découplage associé à un dispositif de connexion par couplage inductif du signal de résonance magnétique a été également démontré à 3 T comme une preuve de concept d'un dispositif de connexion universelle. Ce dispositif a fait l'objet d'un article récemment soumis pour publicationMagnetic resonance imaging {MRl) in veterinary practice employs low magnetostatic field devices which have numerous advantages such as their low maintenance and initial cost. Yet, the radiofrequency {RF) coils commercially provided with these devices are dedicated to human morphology, therefore reducing image quality. ln this work, simple optimization methods for 0.2 T RF coils were developed for an implementation in research and preclinical studies. Optimization protocol was subdivided into two main steps. First, an analytical model was developed using MATLAB in order to estimate the intrinsic signal to noise ratio variations with coil and imaged sample characteristics. Validation of the model was assessed thanks to quality factor comparison between simulated and measured values. The use of the analytical model for two specific studies was described in a recently accepted publication. Second, active decoupling was investigated. lndeed, passive decoupling is the decoupling method implemented on the 0.2 T MR device at our disposal. However, this technique can lack of efficiency in some experiments, inducing imaging artifacts and reduced quality factor. Active decoupling method was therefore implemented. The electronic performances of the coils equipped this way were better than in passive decoupling. This active decoupling device combined with an inductive coupling connecting system was tested at 3 T to demonstrate the technical feasibility of a new universal connecting device, for which an article was recently submitted
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Gupta, Vishal. "Decoupling of Hamiltonian system with applications to linear quadratic problem". Arlington, TX : University of Texas at Arlington, 2007. http://hdl.handle.net/10106/905.
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Fromm, Alexander. "Theory and applications of decoupling fields for forward-backward stochastic differential equations". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2015. http://dx.doi.org/10.18452/17115.
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Diese Arbeit beschäftigt sich mit der Theorie der sogenannten stochastischen Vorwärts-Rückwärts-Differentialgleichungen (FBSDE), welche als ein stochastisches Anologon und in gewisser Weise als eine Verallgemeinerung von parabolischen quasi-linearen partiellen Differentialgleichungen betrachtet werden können. Die Dissertation besteht aus zwei Teilen: In dem ersten entwicklen wir die Theorie der sogenannten Entkopplungsfelder für allgemeine mehrdimensionale stark gekoppelte FBSDE. Diese Theorie besteht aus Existenz- sowie Eindeutigkeitsresultaten basierend auf dem Konzept des maximalen Intervalls. Es beinhaltet darüberhinaus Werkzeuge um Regularität von konkreten Problemen zu untersuchen. Insgesamt wird die Theorie für drei Klassen von Problemen entwickelt: In dem ersten Fall werden Lipschitz-Bedingungen an die Parameter des Problems vorausgesetzt, welche zugleich vom Zufall abhängen dürfen. Die Untersuchung der beiden anderen Klassen basiert auf dem ersten. In diesen werden die Parameter als deterministisch vorausgesetzt. Gleichwohl wird die Lipschitz-Stetigkeit durch zwei verschiedene Formen der lokalen Lipschitz-Stetigkeit abgeschwächt. In dem zweiten Teil werden diese abstrakten Resultate auf drei konkrete Probleme angewendet: In der ersten Anwendung wird gezeigt wie globale Lösbarkeit von FBSDE in dem sogenannten nicht-degenerierten Fall untersucht werden kann. In der zweiten Anwendung wird die Lösbarkeit eines gekoppelten Systems gezeigt, welches eine Lösung zu dem Skorokhod''schen Einbettungproblem liefert. Die Lösung wird für den Fall einer allgemeinen nicht-linearen Drift konstruiert. Die dritte Anwendung führt auf Lösbarkeit eines komplexen gekoppelten Vorwärt-Rückwärts-Systems, aus welchem optimale Strategien für das Problem der Nutzenmaximierung in unvollständingen Märkten konstruiert werden. Das System wird in einem verhältnismäßig allgmeinen Rahmen gelöst, d.h. für eine verhältnismäßig allgemeine Klasse von Nutzenfunktion auf den reellen Zahlen.This thesis deals with the theory of so called forward-backward stochastic differential equations (FBSDE) which can be seen as a stochastic formulation and in some sense generalization of parabolic quasi-linear partial differential equations. The thesis consist of two parts: In the first we develop the theory of so called decoupling fields for general multidimensional fully coupled FBSDE in a Brownian setting. The theory consists of uniqueness and existence results for decoupling fields on the so called the maximal interval. It also provides tools to investigate well-posedness and regularity for particular problems. In total the theory is developed for three different classes of FBSDE: In the first Lipschitz continuity of the parameter functions is required, which at the same time are allowed to be random. The other two classes we investigate are based on the theory developed for the first one. In both of them all parameter functions have to be deterministic. However, two different types of local Lipschitz continuity replace the more restrictive Lipschitz continuity of the first class. In the second part we apply these techniques to three different problems: In the first application we demonstrate how well-posedness of FBSDE in the so called non-degenerate case can be investigated. As a second application we demonstrate the solvability of a system, which provides a solution to the so called Skorokhod embedding problem (SEP) via FBSDE. The solution to the SEP is provided for the case of general non-linear drift. The third application provides solutions to a complex FBSDE from which optimal trading strategies for a problem of utility maximization in incomplete markets are constructed. The FBSDE is solved in a relatively general setting, i.e. for a relatively general class of utility functions on the real line.
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Harb, Souhib. "Three-port micro-inverter with power decoupling capability for photovoltaic (pv) systems applications". Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4683.
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The Photovoltaic (PV) systems have been realized using different architectures, starting with the string and centralized PV system to the modular PV system. Presently, decentralized inverters are being developed at the PV panel power level (known as AC ?? PV Modules). Such new PV systems are becoming more attractive and many expect this will be the trend of the future. The AC-Module PV system consists of an inverter attached to one PV panel. This integration requires that both devices have the same life-span. Although, the available commercial inverters have a relatively short life-span (10 years) compared to the 25 ??year PV. It has been stated in literature that the energy storage capacitor (electrolytic type) in the single-phase inverter is the most vulnerable electronic component. Hence, many techniques such as (power decoupling techniques) have been proposed to solve this problem by replacing the large electrolytic capacitor with a small film capacitor. This thesis will present a quick review of these power decoupling techniques, and proposes a new three-port micro-inverter with power decoupling capability for AC-Module PV system applications.ID: 028732249; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2010.; Includes bibliographical references.
M.S.
Masters
Department of Electrical Engineering and Computer Science
Engineering and Computer Science
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Zheng, Qing. "On Active Disturbance Rejection Control: Stability Analysis and Applications in Disturbance Decoupling Control". Cleveland, Ohio : Cleveland State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1250274093.
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Thesis (D.Eng.)--Cleveland State University, 2009.Abstract. Title from PDF t.p. (viewed on Oct. 26, 2009). Includes bibliographical references (p. 78-89). Available online via the OhioLINK ETD Center and also available in print.
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Scheichl, Robert. "Iterative solution of saddle point problems using divergence-free finite elements with applications to groundwater flow". Thesis, University of Bath, 2000. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341106.
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Mani, Rajesh. "Processing and characterization of polymer-ceramic composite thin film dielectrics for embedded decoupling applications". Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/20840.
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Hong, Jiatu. "Investigation on the DC-AC dual active bridge converter and its photovoltaic applications". Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/116502/1/Jiatu_Hong_Thesis.pdf.
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This thesis presents an investigation on the DC-AC dual active bridge converter and its control method to overcome drawbacks in the existing applications. With the proposed topology and control method, the power ripple can be completely eliminated with a reduced capacitance requirement and therefore the power density and reliability of the converter is enhanced. Furthermore, an example of its application in photovoltaic systems is presented. It is free of the commonly used large capacitor at DC power stages with the proposed control strategy. As a result, high accuracy of maximum power point tracking of the converter can be obtained.
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Salah, Adham M. S. "Investigation of Integrated Decoupling Methods for MIMO Antenna Systems. Design, Modelling and Implementation of MIMO Antenna Systems for Different Spectrum Applications with High Port-to-Port Isolation Using Different Decoupling Techniques". Thesis, University of Bradford, 2019. http://hdl.handle.net/10454/18427.
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Multiple-Input-Multiple-Output (MIMO) antenna technology refers to an antenna with
multiple radiators at both transmitter and receiver ends. It is designed to increase the data rate in
wireless communication systems by achieving multiple channels occupying the same bandwidth
in a multipath environment. The main drawback associated with this technology is the coupling
between the radiating elements. A MIMO antenna system merely acts as an antenna array if the
coupling between the radiating elements is high. For this reason, strong decoupling between the
radiating elements should be achieved, in order to utilize the benefits of MIMO technology.
The main objectives of this thesis are to investigate and implement several printed MIMO
antenna geometries with integrated decoupling approaches for WLAN, WiMAX, and 5G
applications. The characteristics of MIMO antenna performance have been reported in terms of
scattering parameters, envelope correlation coefficient (ECC), total active reflection coefficient
(TARC), channel capacity loss (CCL), diversity gain (DG), antenna efficiency, antenna peak gain
and antenna radiation patterns.
Three new 2×2 MIMO array antennas are proposed, covering dual and multiple spectrum
bandwidths for WLAN (2.4/5.2/5.8 GHz) and WiMAX (3.5 GHz) applications. These designs
employ a combination of DGS and neutralization line methods to reduce the coupling caused by
the surface current in the ground plane and between the radiating antenna elements. The minimum
achieved isolation between the MIMO antennas is found to be better than 15 dB and in some
bands exceeds 30 dB. The matching impedance is improved and the correlation coefficient values
achieved for all three antennas are very low. In addition, the diversity gains over all spectrum
bands are very close to the ideal value (DG = 10 dB).
The forth proposed MIMO antenna is a compact dual-band MIMO antenna operating at
WLAN bands (2.4/5.2/5.8 GHz). The antenna structure consists of two concentric double square
rings radiating elements printed symmetrically. A new method is applied which combines the
defected ground structure (DGS) decoupling method with five parasitic elements to reduce the
coupling between the radiating antennas in the two required bands.
A metamaterial-based isolation enhancement structure is investigated in the fifth proposed
MIMO antenna design. This MIMO antenna consists of two dual-band arc-shaped radiating
elements working in WLAN and Sub-6 GHz 5th generation (5G) bands. The antenna placement
and orientation decoupling method is applied to improve the isolation in the second band while
four split-ring resonators (SRRs) are added between the radiating elements to enhance the
isolation in the first band.
All the designs presented in this thesis have been fabricated and measured, with the simulated
and measured results agreeing well in most cases.Higher Committee for Education Development in Iraq (HCED)
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Kipp, Alexander [Verfasser], i Michael [Akademischer Betreuer] Resch. "Increased flexibility and dynamics in distributed applications and processes through resource decoupling / Alexander Kipp. Betreuer: Michael Resch". Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2015. http://d-nb.info/1066645736/34.
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Hobbs, Joseph Martin. "Integration of thin film polymer ceramic nanocomposite capacitor dielectrics in SOP for decoupling applications in high speed digital communications". Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/32968.
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Gavito, Valentin F. Jr. "Applications of eigenstructure assignment to design of robust mimo decoupling controllers and to reconfiguration algorithms for damaged flight control". Thesis, Monterey, California: U.S. Naval Postgraduate School, 1986. http://hdl.handle.net/10945/21676.
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Fromm, Alexander [Verfasser], Peter [Akademischer Betreuer] Imkeller, Stefan [Akademischer Betreuer] Ankirchner i Anthony [Akademischer Betreuer] Réveillac. "Theory and applications of decoupling fields for forward-backward stochastic differential equations / Alexander Fromm. Gutachter: Peter Imkeller ; Stefan Ankirchner ; Anthony Réveillac". Berlin : Humboldt Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2015. http://d-nb.info/1065723083/34.
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HUYNH, SYLVIE. "Microcalorimetrie de la protonation : application a l'etude du metabolisme des derives nitroses". Caen, 1985. http://www.theses.fr/1985CAEN2020.
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Application de la microcalorimetrie a l'etude des derives nitroses qui suscitent un interet toxicologique certain et servent de substrat a des systemes enzymatiques qui les degradent et modifient leur activite
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Choa-Ching, Yu, i 游兆睛. "Application of Decoupling Capacitor for Improving Power Delivery System Integrity". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/01259880112123190268.
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碩士大葉大學
電信工程學系碩士班
93
This paper presents the simulation of electromagnetic fields on the effects of decoupling capacitors for reduction of Delta-I noise in PCB (Printed Circuit Board). The signal propagating through the vias of the multi-layer environment will suffer from composite effect of reflected noise due to via discontinuity and ground bounce between power and ground planes. This paper investigates the plane impedance of PCB. The same results have compared by Sigrity Speed XP Suite, and measurement.
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LI, REN-HUI, i 李仁揮. "Robust decoupling design and its application to flight control system". Thesis, 1991. http://ndltd.ncl.edu.tw/handle/92407414183123841324.
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Chan, Yu-Hsia, i 詹玉霞. "Application of Decoupling Fuzzy Control on Thermal Management for Variable Servers". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/69704491928331073934.
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Hu, Jing-Ning, i 胡晉寧. "Application of Parasitic Elements for Decoupling and Matching on Multiple Antennas System". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/28986726608334170691.
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廖至國. "Application of Mass Customization the customer order decoupling point in Bicycles Manufacturing". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/98570445772535859163.
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廖團訓. "On the Study of the Sequential Eigenstructure Assignment and Its Application to Mode Decoupling and Minimum Eigenvalue Sensitivity". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/46585352405439290974.
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碩士國立中央大學
電機工程研究所
88
The multi-objective control system design, such as a control system having simultaneously different performance criteria; for instance, system stability, dynamic response, minimum eigenvalue sensitivity, and mode decoupling, becomes very important tasks for the modern control engineers. Hence, eigenvalue assignment methods have been not satisfied for recent control system design techniques. Therefore, the eigenstructure assignment methods have received considerable attentions and great fruits in last decades. In recent year, a sequential eigenstructure assignment method, which can improve the common disadvantage of the entire eigenstructure assignment method, is proposed. In the algorithm of the sequential eigenstructure assignment method, only one or a group of eigenvectors are assigned at one time. It is easier to achieve the invertible modal matrix in the sequential eigenstructure assignment method than that in the entire eigenstructure assignment method. In this thesis, we propose an alternative scheme for the sequential eigenstructure assignment via linear state-variable feedback, which has the simple structure and time-saving decomposition for the original system matrix. And it has successful application to minimum eigenvalue sensitivity and mode decoupling for linear multi-input systems.
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Lin, Kai-chi, i 林凱麒. "Dual-band decoupling network for closely spaced array in MIMO applications". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/9qkc5x.
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碩士國立臺灣科技大學
電機工程系
99
A novel decoupling system for closely spaced dual-band antenna array is proposed in this thesis. To simultaneously achieve dual-band decoupling and impedance matching, new synthesized transmission lines are proposed and discussed. The new architecture is capable of effectively improving the transmission efficiency of a multiple-input-multiple-output (MIMO) system with compact circuit size. The lower and upper bands of the proposed dual-band decoupling system are realized by the 180-degree hybrid coupler and shunt reactance elements, respectively. To fulfill this distinct dual-mode property, two novel synthesized transmission lines are proposed. The 50-ohm synthesized line can be equivalent to its conventional counterpart in the lower band, but introduces a transmission zero with nearly open-circuited input impedance in the upper band. Similarly, the proposed 35-ohm synthesized line functions as a conventional 35-ohm microstrip line in the lower band, but features a 50-ohm equivalent characteristic impedance in the upper band. By utilizing the proposed synthesized lines, a dual-mode 180-degree hybrid coupler is developed. The dual-mode hybrid coupler shows comparable electrical performances with its conventional counterpart when operating in the lower band. In the upper band, due to the perfectly open-circuited responses of the synthesized lines, it can be equivalent to a pair of isolated transmission lines with direct-thru transmission properties. Two unique closely-spaced dual-band antenna arrays are developed to validate the signal decoupling capability of the proposed new architecture. The simulation and measurement agree well with each other. By analyzing the excited currents on the antenna elements, the low radiation efficiency issue in the lower band is discussed and successfully resolved.
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Lin, Han Tin, i 林漢庭. "Decoupling Methods of Magnetic Resonance Imaging Array Coils and Its Biomedical Applications". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/33190180295655203341.
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碩士臺灣大學
電機工程學研究所
95
In MRI (Magnetic Resonance Imaging) system, phased-array coils have been used to have high signal-to-noise (SNR) as well as to cover big field-of-view (FOV). When the numbers of coils increases, the coupling between coils get increased also. How to decrease the mutual inductance between these coils is the main goal of this thesis. In these several years, array coils have also combine parallel imaging to reduce the acquisition time for fast imaging applications. Overlap decoupling, capacitive decoupling, and preamplifier decoupling theories are introduced in this thesis. These decoupling methods are also verified by HFSS simulation, which can create 3D models for real coils situations, and provide rule of thumb for coil design. In addition to theory and simulations, two channel array coils were designed with overlap and capacitive decoupling for phantom and mice at 3T MRI in National Taiwan University. Advantages and disadvantages of these two methods are also discussed. A hybrid method cover these two methods was also designed for mice anatomic imaging. Preamplifier decoupling was also introduced due to the limitation of decoupling effects for complicated geometry coil for these two methods. We take advantage of preamplifier decoupling with low input impedance for better decoupling in complicated coil configuration. Three channel spine array coils and four channel whole body array coils was implemented with better isolated images (<-25dB) in phantom and mice study than overlap and capacitive decoupling theory (almost >-20dB) of it. These multi-channel array could successfully used to reduce sampling time to half by SENSE(Sensitivity encoding) reconstruction. These design techniques of coils and preamplifiers could be used for large number of channels in future applications widely. IC fabrication as well wireless technology will be covered in the future studies.
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Chen, Shin-Chang, i 陳信錩. "Decoupling Techniques for Increasing the Isolation Between Two Nearby Antennas for Wireless Communication Applications". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/27tpc7.
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碩士國立交通大學
電信工程系所
95
In this study, we will introduce two methods of decoupling design. At the first method, it is composed of the decoupling network and the matching network, and the radiation pattern with function of pattern diversity. We were using the ABCD matrix, the S parameter, the Y matrix and the Z matrix to analyze the characteristic of this structure. At the second method, we were using the branch line coupler to exchange the coupled and the return loss so the high isolation antenna will be manufacture. Also, this type antenna has the radiation pattern with function of pattern diversity. We using the antenna factor to explain the diversity of the radiation pattern, the simulated and the measured results almost conform to the specifications.
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Hung, Guo-Chiang, i 洪國強. "Applications of moats, voltage regulator modules and decoupling capacitors on suppressing delta-I noise". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/qf95n5.
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碩士國立臺北科技大學
電腦與通訊研究所
93
The main purpose of this thesis is to reduce the delta-I noise when the drivers switch from one state to another and prevent noise to interference the state of another component. The DC noise will be improved in this thesis. A large number of structures will be discusses to improve the delta-I noise, i.e. etch slot and put ferrite bead between the component and another component to isolated delta-I noise. This method not only increases the cost of product and the ferrite bead is low pass circuit that will make signal integrity problem. In order to improve the shortcomings mentioned above, this thesis proposes a new improvement method, which will have the metal between two districts on the power plane and around the component by slot. That will put de-capacitors at metal to isolated delta-I noise and use voltage regulator module to improve DC noise. Finally, through the consistency of simulation and measurement the proposed method is available. The results presented in the thesis show use few de-capacitors、etch slot and put voltage regulator module have a potential value on practical application to improve the effect of delta-I noise.
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Wu, Sheng-Yao, i 吳聲堯. "The Applications of Inverse Disturbance Response Decoupling and Mechatronic Inerter Networks to an Optical Table". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/22088981531989190342.
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碩士國立臺灣大學
機械工程學研究所
101
In this thesis, we discuss the design and control of an optical table. An optical table must isolate two main vibration sources: the load disturbances from the machines and the ground disturbances from the environment. Because the suspension settings for suppressing these two disturbances are conflicting, we design a double-layer structure and apply disturbance response decoupling (DRD) theorem to independently treat these two vibration sources. This thesis focuses on the following three topics: mechatronic inerter networks, the inverse DRD structure, and the simplified optical table. First, we apply the mechatronic inerter network to the passive suspension layer. In the previous studies, we used a commercial I-2000 legs to isolate the ground disturbance in a passive way and applied piezoelectric transducers as active actuators to improve the load responses. Therefore, in this thesis we extend these ideas by replacing the I-2000 legs by mechatronic inerter networks and optimize the ground disturbance responses by connecting suitable electric circuits. Second, we propose the inverse DRD structure to the optical table. In the previous works, we used soft passive structure to repress the ground disturbances, and improve the load responses by active control. Though the results demonstrated the effectiveness of DRD techniques, however, the soft passive structure might result in large vibrations to load disturbances and damage the precision machines. Therefore, in this thesis we design an inverse DRD structure that uses stiff elements to suppress the load disturbances in a passive way and improves the ground disturbance responses by active control. Lastly, we simplified the optical table system to reduce the cost of hardware. The original optical table consists of four legs. But we assume the table as rigid body, so that the warp mode can be neglected. Therefore, we can use three legs to construct the optical table that can achieve the same performance as the original design. We design and implement the aforementioned three control structures to a full optical table. Based on the simulation and experimental results, the proposed designs are deemed effective in suppressing system vibrations.
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Guo, Geng-Lin, i 郭畊麟. "Applications of Fuzzy Brain Emotional Cerebellar Model Articulation Controller for SIMO Nonlinear System Decoupling Control". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/p946yp.
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碩士元智大學
電機工程學系
106
In this thesis, a Fuzzy Brain Emotional Cerebellar Model Articulation Controller (FBECMAC) is designed for the decoupling nonlinear systems. For the underactuated systems, the decoupling sliding-mode technique is used to achieve the decoupling control performance. The FBECMAC combines cerebellar model with a brain model to introduce a new neural network model, which imitates the judgment of a cerebellar and the emotion of a brain. The brain has an amygdala cortex and a prefrontal cortex, so that the FBECMAC contains two neural networks; the amygdala cortex is a sensory neural network and the prefrontal cortex is an emotional neural network. The proposed FBECMAC has learning ability and can adjust parameters to achieve efficient control performance. The proposed control system is comprised of a FBECMAC and an auxiliary compensation controller. The FBECMAC is used as the main controller to approximate an ideal controller to achieve desired control performance and the auxiliary compensation controller is utilized to attenuate the residual approximation error to achieve system stability. Finally, the FBECMAC control system is used to control a ball-beam system, a Translational Oscillations with a Rotational Actuator(TORA) system, a bridge-crane, an aeroelastic structure system and a double-inverted pendulum system to confirm the validity of the proposed approach.
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Alibakhshikenari, M., B. S. Virdee, C. H. See, Raed A. Abd-Alhameed, F. Falcone, A. Andujar, J. Anguera i E. Limiti. "Study on antenna mutual coupling suppression using integrated metasurface isolator for SAR and MIMO applications". 2018. http://hdl.handle.net/10454/18117.
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YesA metasurface based decoupling structure that is composed of a square-wave slot pattern with exaggerated corners that is implemented on a rectangular microstrip provides high-isolation between adjacent patch antennas for Synthetic Aperture Radar (SAR) and Multi-Input-Multi-Output (MIMO) systems. The proposed 1×2 symmetric array antenna integrated with the proposed decoupling isolation structure is designed to operate at ISM bands of X, Ku, K, and Ka. With the proposed mutual coupling suppression technique (i) the average isolation in the respective ISM bands listed above is 7 dB, 10 dB, 5 dB, and 10 dB; and (ii) edge-to-edge gap between adjacent radiation elements is reduced to 10 mm (0.28λ). The average antenna gain improvement with the metasurface isolator is 2 dBi.
H2020-MSCA-ITN-2016 SECRET-722424 and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E0/22936/1
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Alibakhshikenari, M., B. S. Virdee, P. Shukla, C. H. See, Raed A. Abd-Alhameed, M. Khalily, F. Falcone i E. Limiti. "Interaction between closely packed array antenna elements using metasurface for applications such as MIMO systems and synthetic aperture radars". 2018. http://hdl.handle.net/10454/16635.
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YesThe paper presents a technique to enhance the isolation between adjacent radiating elements which is common in densely packed antenna arrays. Such antennas provide frequency beam-scanning capability needed in Multiple-Input Multiple-Output (MIMO) systems and Synthetic Aperture Radars (SARs). The method proposed here uses a metamaterial decoupling slab (MTMDS), which is located between radiating elements, to suppress mutual-coupling between the elements that would otherwise degrade the antenna efficiency and performance in both the transmit and receive mode. The proposed MTM-DS consists of mirror imaged Eshaped slits engraved on a microstrip patch with inductive stub. Measured results confirm over 9–11 GHz with no MTM-DS the average isolation (S12) is -27 dB; however, with MTM-DS the average isolation improves to -38 dB. With this technique the separation between the radiating element can be reduced to 0.66λo, where λ0 is free space wavelength at 10 GHz. In addition, with this technique there is 15% improvement in operating bandwidth. At frequencies of high impedance match of 9.95 GHz and 10.63 GHz the gain is 4.52 dBi and 5.40 dBi, respectively. Furthermore, the technique eliminates poor front-to-back ratio encountered in other decoupling methods. MTM-DS is also relatively simple to implement. Assuming adequate space is available between adjacent radiators the MTM-DS can be fixed retrospectively on existing antenna arrays, which makes the proposed method versatile.
Partially supported by innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET- 722424 and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1.