Dissertations / Theses on the topic 'Control of PDEs'
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BACCOLI, ANTONELLO. "Boundary control and observation of coupled parabolic PDEs." Doctoral thesis, Università degli Studi di Cagliari, 2016. http://hdl.handle.net/11584/266880.
Hein, Sabine. "MPC/LQG-Based Optimal Control of Nonlinear Parabolic PDEs." Doctoral thesis, Universitätsbibliothek Chemnitz, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-201000134.
Torres, Ixbalank. "Simulation and control of denitrification biofilters described by PDEs." Toulouse 3, 2010. http://thesesups.ups-tlse.fr/1204/.
This thesis addresses the simulation and control of a denitrification biofilter. Parabolic and hyperbolic PDE models may be considered, which depends on the fact of considering or neglecting the diffusion phenomenon. In plus of the classical methods of lines, approaches specific to the type of PDE system are evaluated to simulate the biofilter. The method of characteristics applies to hyperbolic PDE systems. The modal analysis used on the parabolic PDE system allows manipulating a reduced order model. The control objective is then the reduction of the nitrogen concentration at the output of the reactor below some pre-specified upper limit, in spite of the external disturbances and uncertainties of the model. Two control strategies are considered. An early lumping approach is used to synthesize an observer-based H2 output feedback linear controller. A late lumping approach associates a linearizing control to a distributed parameter observer
Liu, Bainan. "Boundary Observer-based 0utput Feedback Control of Coupled Parabolic PDEs." Thesis, Bourges, INSA Centre Val de Loire, 2018. http://www.theses.fr/2018ISAB0011.
This thesis aims to design a boundary observer-based output feedback controllerfor a class of systems modelled by linear coupled parabolic PDEs by using the backsteppingmethod.Roughly speaking, the backstepping method for PDEs mainly consists oftransforming some kinds of PDEs into some particular PDEs, that are easy to analyzeand stabilize by using controllers or observers. This kind of particular PDEs will becalled target systems. Firstly, it considers an easy case of coupled reaction-diffusionequations with the same constant diffusion parameter. For this case, it proposes amore relaxed stability condition for the target system of the backstepping transformation.Moreover, for the same case, it designs a backstepping boundary observer-basedoutput feedback controller. Then, it takes an example to verify the proposed method.It also deals with a class of systems modelled by reaction-advection-diffusion equationswith the same constant diffusion parameter, which are realized by proposingparticular conditions on the target systems. Secondly, it deals with a kind of systemsmodelled by coupled reaction-diffusion equations with different diffusions. In a similarway, it designs a boundary observer for this kind of systems. However, due to thefact that the constant diffusions are not the same, it is more difficult to solve the kernelfunctions of the backstepping transformation than the same diffusion case. Forthis, an assumption on the kernel functions is made to enable us to solve the problem.Moreover, it also designs a backstepping boundary controller based on the proposedstability conditions. Those stability conditions are more relaxed than the conditionswe can find in the literatures on this topic. Then, based on the Separation Principle,it designs an observer-based output feedback controller. It takes a simplified modelof Chemical Tubular Reactor to highlight the proposed method. Thirdly, this thesisdesigns a boundary observer as a more general extension by studying a class of systemsmodelled by coupled reaction-advection-diffusion equations with spatially-varyingcoefficients, which is more challenged to solve kernel functions of the backsteppingtransformation. To achieve this, it transforms the parabolic kernel equations into a setof hyperbolic equations. Then, it proves the well-posedness by setting suitable boundaryconditions for the kernel functions. Moreover, it also provides the stability conditionsfor the target systems. The performance of the proposed observer is illustrated bytaking a numerical model. Fourthly, it extends the above backstepping observer-basedoutput feedback controller to fractional-order PDE systems. Finally, conclusions areoutlined with some perspectives
Cirant, Marco A. "Nonlinear PDEs in ergodic control, Mean Field Games and prescribed curvature problems." Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3423511.
Questa tesi ha come oggetto di studio EDP ellittiche nonlineari e sistemi di EDP che si presentano in problemi di controllo stocastico, giochi differenziali, in particolare Mean Field Games e geometria differenziale. I risultati contenuti si possono suddividere in tre parti. Nella prima parte si pone l'attenzione su problemi di controllo ergodico stocastico dove lo spazio degli stati e dei controlli coincide con l'intero Rd. L'interesse è posto sul formulare condizioni sul drift, il funzionale di costo e la Lagrangiana sufficienti a sintetizzare un controllo ottimo di tipo feedback. Al fine di ottenere tali condizioni, viene proposto un approccio che combina il metodo delle funzioni di Lyapunov e l'approssimazione del problema su domini limitati con riflessione delle traiettorie al bordo. Le tecniche vengono formulate in termini generali e successivamente sono presi in considerazione esempi specifici, che mostrano come opportune funzioni di Lyapunov possono essere costruite a partire dalle soluzioni dei problemi approssimanti. La seconda parte è incentrata sullo studio di Mean Fielda Games, una recente teoria che mira a elaborare modelli per analizzare processi di decisione in cui è coinvolto un grande numero di agenti indistinguibili. Sono ottenuti nella tesi alcuni risultati di esistenza di soluzioni per sistemi MFG a più popolazioni con condizioni al bordo omogenee di tipo Neumann, attraverso stime a-priori ellittiche e argomenti di punto fisso. Viene in seguito proposto un modello di segregazione tra popolazioni umane che prende ispirazione da alcune idee di T. Schelling. Tale modello si inserisce nel contesto teorico sviluppato nella tesi, e viene analizzato dal punto di vista qualitativo tramite tecniche numeriche alle differenze finite. Il fenomeno di segregazione tra popolazioni si riscontra negli esperimenti numerici svolti sul particolare modello mean field, assumendo l'ipotesi di moderata mentalità etnocentrica delle persone, similmente all’originale modello di Schelling. L'ultima parte della tesi riguarda alcuni risultati di esistenza e unicità di soluzioni per l’equazione di k-esima curvatura principale prescritta. Il problema di Dirichlet per tale famiglia di equazioni ellittiche degeneri nonlineari è risolto implementando la teoria delle soluzioni di Viscosità, applicando in particolare una versione del metodo di Perron basata su soluzioni semiconvesse; la restrizione a tale classe di funzioni risulta sufficiente per dimostrare una stima di tipo Lipschitz sull'operatore ellittico, essenziale per ottenere un principio di confronto. Esistenza e unicità di soluzioni sono formulate in termini generali; vengono forniti infine esempi in cui condizioni particolari sui dati soddisfano tali ipotesi.
Götschel, Sebastian [Verfasser]. "Adaptive Lossy Trajectory Compression for Optimal Control of Parabolic PDEs / Sebastian Götschel." Berlin : Freie Universität Berlin, 2015. http://d-nb.info/1066645221/34.
Tan, Xiaolu. "Stochastic control methods for optimal transportation and probabilistic numerical schemes for PDEs." Palaiseau, Ecole polytechnique, 2011. https://theses.hal.science/docs/00/66/10/86/PDF/These_TanXiaolu.pdf.
This thesis deals with the numerical methods for a fully nonlinear degenerate parabolic partial differential equations (PDEs), and for a controlled nonlinear PDEs problem which results from a mass transportation problem. The manuscript is divided into four parts. In a first part of the thesis, we are interested in the necessary and sufficient condition of the monotonicity of finite difference thêta-scheme for a one-dimensional diffusion equations. An explicit formula is given in case of the heat equation, which is weaker than the classical Courant-Friedrichs-Lewy (CFL) condition. In a second part, we consider a fully nonlinear degenerate parabolic PDE and propose a splitting scheme for its numerical resolution. The splitting scheme combines a probabilistic scheme and the semi-Lagrangian scheme, and in total, it can be viewed as a Monte-Carlo scheme for PDEs. We provide a convergence result as well as a rate of convergence. In the third part of the thesis, we study an optimal mass transportation problem. The mass is transported by the controlled drift-diffusion dynamics, and the associated cost depends on the trajectories, the drift as well as the diffusion coefficient of the dynamics. We prove a strong duality result for the transportation problem, thus extending the Kantorovich duality to our context. The dual formulation maximizes a value function on the space of all bounded continuous functions, and every value function corresponding to a bounded continuous function is the solution to a stochastic control problem. In the Markovian cases, we prove the dynamic programming principle of the optimal control problems, and we propose a gradient-projection algorithm for the numerical resolution of the dual problem, and provide a convergence result. Finally, in a fourth part, we continue to develop the dual approach of mass transportation problem with its applications in the computation of the model-independent no-arbitrage price bound of the variance option in a vanilla-liquid market. After a first analytic approximation, we propose a gradient-projection algorithm to approximate the bound as well as the corresponding static strategy in vanilla options
Xia, Xiaonyu. "Singular BSDEs and PDEs Arising in Optimal Liquidation Problems." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21040.
This dissertation analyzes BSDEs and PDEs with singular terminal condition arising in models of optimal portfolio liquidation. Portfolio liquidation problems have received considerable attention in the financial mathematics literature in recent years. Their main characteristic is the singular terminal condition of the value function induced by the liquidation constraint, which translates into a singular terminal state constraint on the associated BSDE or PDE. The dissertation consists of three chapters. The first chapter analyzes a multi-asset portfolio liquidation problem with instantaneous and persistent price impact and stochastic resilience. We show that the value function can be described by a multi-dimensional BSRDE with a singular terminal condition. We prove the existence of a solution to this BSRDE and show that it can be approximated by a sequence of the solutions to BSRDEs with finite increasing terminal condition. A novel a priori estimate for the approximating BSRDEs is established for the verification argument. The second chapter considers a portfolio liquidation problem with unbounded cost coefficients. We establish the existence of a unique nonnegative continuous viscosity solution to the HJB equation. The existence result is based on a novel comparison principle for semi-continuous viscosity sub-/supersolutions for singular PDEs. Continuity of the viscosity solution is enough to carry out the verification argument. The third chapter studies an optimal liquidation problem under ambiguity with respect to price impact parameters. In this case the value function can be characterized by the solution to a semilinear PDE with superlinear gradient. We first prove the existence of a solution in the viscosity sense by extending our comparison principle for singular PDEs. Higher regularity is then established using an asymptotic expansion of the solution at the terminal time.
Trenz, Stefan [Verfasser]. "POD-Based A-posteriori Error Estimation for Control Problems Governed by Nonlinear PDEs / Stefan Trenz." Konstanz : Bibliothek der Universität Konstanz, 2017. http://d-nb.info/1142113868/34.
Branco, Meireles Joao. "Singular Perturbations and Ergodic Problems for degenerate parabolic Bellman PDEs in R^m with Unbounded Data." Doctoral thesis, Università degli studi di Padova, 2015. http://hdl.handle.net/11577/3424194.
In questa tesi viene trattato con successo il primo problema di perturbazione singolare di un modello stocastico con variabili veloci controllate e non limitate. I metodi si basano sulla teoria delle soluzioni di viscosità, omogeinizzazione dei PDE completamente non lineari, e su un'attenta analisi del problema stocastico ergodico associato, valido nell'intero spazio R^m. Il testo è diviso in due parti. Nel primo capitolo, saranno studiate l'esistenza, l'unicità e alcune proprietà di stabilità della soluzione del problema ergodico, riferito sopra, che sono essenziali per caratterizzare il Hamiltoniano effettivo che appare in un Problema di Cauchy "limite", che sarà descritto nel capitolo II di questa tesi. Il principale contributo, presentato in questa parte, è una prova puramente analitica dell'unicità della soluzione di questo problema ergodico. Siccome lo stato dello spazio del problema non è compatto, in generale ci sono un numero infinito di soluzioni a questo problema. Tuttavia, se uno limitasse la classe di soluzioni all'insieme di funzioni limitate inferiormente, allora è noto che l'unicità sarà mantenuta a meno di una costante. La prova esistente si basa su alcune tecniche probabilistiche che impiegano la misura di probabilità invariante per l'associato processo stocastico. Qua verrà data una nuova prova, puramente analitica, basata sul principio del massimo. Si ritiene che il risultato potrà essere interessante ed utile per i ricercatori che lavorano all'interno della comunità di ricerca delle Equazioni Differenziali alle derivate Parziali (PDE). Nel secondo capitolo, sarà introdotto un modello di perturbazione singolare di un problema di controllo stocastico, e provato il risultato principale: la convergenza della funzione valore $V^\epsilon$, associata al nostro problema, per soluzione dell'equazione limite. Più precisamente, sarà provato che le funzioni: \underline{V} (t,x):=\liminf_{(\epsilon,t',x') \to (0,t,x)} \inf_{y \in \mathbb{R}^m} V^\epsilon (t',x',y) e \bar{V} (t,x) :=(\sup_{R} \bar{V}_R)^* (t,x) \text{ (upper semi-continuous envelope of $\sup_{R} \bar{V}_R$ )} dove $\bar{V}_{R} (t,x):=\limsup_{(\epsilon, t',x') \to (0,t,x)} \sup_{y \in B_R (0)} V^\epsilon (t',x',y)$, sono, rispettivamente, una super soluzione e una sottosoluzione del problema effettivo di Cauchy. Come corollario di questo risultato, $V^\epsilon$ converge all'unica soluzione V della equazione effettiva se l'equazione limite permette il principio di comparazione per le soluzioni di viscosità discontinue. La motivazione di questa convergenza non è ovvia del tutto. Coinvolge specialmente alcuni problemi di regolarità e un trattamento attento delle tecniche di viscosità e di analisi stocastica. Questo risultato è nuovo e non è mai stato ottenuto, prima d'ora, nella letteratura Matematica.
Ahmad, Ali Ahmad [Verfasser], and Michael [Akademischer Betreuer] Hinze. "Optimal control of semilinear elliptic PDEs with state constraints - numerical analysis and implementation / Ahmad Ahmad Ali ; Betreuer: Michael Hinze." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2017. http://d-nb.info/1137323736/34.
Ahmad, Ali Ahmad Verfasser], and Michael [Akademischer Betreuer] [Hinze. "Optimal control of semilinear elliptic PDEs with state constraints - numerical analysis and implementation / Ahmad Ahmad Ali ; Betreuer: Michael Hinze." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2017. http://nbn-resolving.de/urn:nbn:de:gbv:18-86259.
Torres, Zuniga Jesus Ixbalank. "Simulation and control of denitrification biofilters described by PDEs Simulation et commande d'un biofiltre de dénitrification décrit par des EDP." Phd thesis, Université Paul Sabatier - Toulouse III, 2010. http://tel.archives-ouvertes.fr/tel-00512336.
Izydorczyk, Lucas. "Probabilistic backward McKean numerical methods for PDEs and one application to energy management." Electronic Thesis or Diss., Institut polytechnique de Paris, 2021. http://www.theses.fr/2021IPPAE008.
This thesis concerns McKean Stochastic Differential Equations (SDEs) to representpossibly non-linear Partial Differential Equations (PDEs). Those depend not onlyon the time and position of a given particle, but also on its probability law. In particular, we treat the unusual case of Fokker-Planck type PDEs with prescribed final data. We discuss existence and uniqueness for those equations and provide a probabilistic representation in the form of McKean type equation, whose unique solution corresponds to the time-reversal dynamics of a diffusion process.We introduce the notion of fully backward representation of a semilinear PDE: thatconsists in fact in the coupling of a classical Backward SDE with an underlying processevolving backwardly in time. We also discuss an application to the representationof Hamilton-Jacobi-Bellman Equation (HJB) in stochastic control. Based on this, we propose a Monte-Carlo algorithm to solve some control problems which has advantages in terms of computational efficiency and memory whencompared to traditional forward-backward approaches. We apply this method in the context of demand side management problems occurring in power systems. Finally, we survey the use of generalized McKean SDEs to represent non-linear and non-conservative extensions of Fokker-Planck type PDEs
Saak, Jens. "Efficient Numerical Solution of Large Scale Algebraic Matrix Equations in PDE Control and Model Order Reduction." Doctoral thesis, Universitätsbibliothek Chemnitz, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200901642.
Mo, Weilan. "Human heart β-adrenoceptors, arrhythmias and control by phosphodiesterases." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/125160/1/Weilan%20Mo%20Thesis.pdf.
Fodjo, Eric. "Algorithms for the resolution of stochastic control problems in high dimension by using probabilistic and max-plus methods." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLX034/document.
Stochastic optimal control problems with finite horizon are a class of optimal control problems where intervene stochastic processes in a bounded time. As many optimal control problems, they are often solved using a dynamic programming approach which results in a second order Partial Differential Equation (PDE) called the Hamilton-Jacobi-Bellman equation. Grid-based methods, probabilistic methods or more recently max-plus methods can be used then to solve this PDE. However, the first type of methods default in a space of high dimension because of the curse of dimensionality while the second type of methods allowed till now to solve only problems where the nonlinearity of the PDE with respect to the second order derivatives is not very high. As for the third type of method, it results in an explosion of the complexity of the value function. We introduce two new probabilistic schemes in order to enlarge the class of problems that can be solved with probabilistic methods. One is adapted to PDE with bounded coefficients while the other can be applied to PDE with bounded or unbounded coefficients. We prove the convergence of the two probabilistic scheme and obtain error estimates in the case of a PDE with bounded coefficients. We also give some results about the behavior of the second probabilistic scheme in the case of a PDE with unbounded coefficients. After that, we introduce a completely new type of method to solve stochastic optimal control problems with finite horizon that we call the max-plus probabilistic method. It allows to add the non linearity feature of max-plus methods to a probabilistic method while controlling the complexity of the value function. An application to the computation of the optimal super replication price of an option in an uncertain correlation model is given in a 5 dimensional space
Jain, Sachin. "Multiresolution strategies for the numerical solution of optimal control problems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22656.
Committee Chair: Tsiotras, Panagiotis; Committee Member: Calise, Anthony J.; Committee Member: Egerstedt, Magnus; Committee Member: Prasad, J. V. R.; Committee Member: Russell, Ryan P.; Committee Member: Zhou, Hao-Min.
Redaud, Jeanne. "Robust control of linear hyperbolic partial differential equations systems interconnected in a chain." Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPAST153.
This thesis focuses on designing robust output-feedback backstepping-based controllers for hyperbolic partial differential equation (PDE) systems interconnected in a chain structure. We take advantage of connections between the class of hyperbolic PDE systems under consideration and time-delay systems of the neutral type presented in Part I. Then, we focus on two classes of chain structures. First, we consider the case where the actuation is available at one end (Part II) for two different networks (ODE-PDE-ODE and arbitrarily many N PDEs-ODE). Such chain structures can be found in drilling applications. Next, we consider a simple chain of two hyperbolic PDE subsystems where the actuation is available at the junction (Part III). A more general integral transform is necessary for its stabilization. Finally, we explore controller design tuning and implementation limitations of backstepping-based controllers (Part IV). We question the choice of a reachable target system with specific stability properties. Additionally, we examine the potential of machine learning techniques to improve computation time in distributed state and parameter estimation
Riahi, Mohamed Kamel. "Conception et analyse d'algorithmes parallèles en temps pour l'accélération de simulations numériques d'équations d'évolution." Phd thesis, Université Paris-Sorbonne - Paris IV, 2012. http://tel.archives-ouvertes.fr/tel-00870821.
Galindo, Tovar Alejandro. "Control por fosfodiesterasas de la función cardíaca activada por los receptores acoplados a la proteína Gs." Doctoral thesis, Universidad de Murcia, 2009. http://hdl.handle.net/10803/10798.
Myocardial β-adrenoceptors (βAR) and serotonin receptors (5-HT4) mediate their signals through the receptor-Gs-AC-cAMP pathway. Phosphodiesterases (PDEs) are a large enzyme family that degrade cAMP. It was unknown which PDE isoenzymes are responsible for the hydrolysis of the cAMP in different cardiac regions. The aim of this doctoral thesis is to investigate which isoenzymes have a role in human, porcine and rodent myocardium. We performed chronotropic, inotropic, lusitropic, biochemical and electrophysiological studies. The key results are: PDEs have different roles in different cardiac regions and cellular compartments; and the basal beating rate of the sinoatrial node is controlled by PDE3 and/or PDE4, but these PDEs do not limit the tachycardia mediated through the stimulation of β1AR, β2AR and 5-HT4. Given the diverse roles of PDE3 and PDE4 and their dependence on species, extrapolation to humans should be done cautiously because these animal models usually do not reflect the human myocardium.
Wang, Hsuan. "Access control in XML PDMS query answering." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31428.
Science, Faculty of
Computer Science, Department of
Graduate
Morancey, Morgan. "Contrôle d'équations de Schrödinger et d'équations paraboliques dégénérées singulières." Phd thesis, Ecole Polytechnique X, 2013. http://tel.archives-ouvertes.fr/tel-00910985.
Haine, Ghislain. "Observateurs en dimension infinie. Application à l'étude de quelques problèmes inverse." Phd thesis, Université de Lorraine, 2012. http://tel.archives-ouvertes.fr/tel-00750725.
Hudson, Thomas. "Stability and regularity of defects in crystalline solids." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:48ab1e44-f81a-4de0-b380-6fb0411bf1a9.
Vidard, Arthur. "Assimilation de données et méthodes adjointes pour la géophysique." Habilitation à diriger des recherches, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00939130.
Egloffe, Anne-Claire. "Etude de quelques problèmes inverses pour le système de Stokes. Application aux poumons." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00756334.
Shang, Peipei. "Analyse mathématique et contrôle optimal de lois de conservation multi-échelles : application à des populations cellulaires structurées." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00847756.
SCODINA, STEFANO. "Observation and control of PDE with disturbances." Doctoral thesis, Università degli Studi di Cagliari, 2012. http://hdl.handle.net/11584/266149.
Dapogny, Charles. "Optimisation de formes, méthode des lignes de niveaux sur maillages non structurés et évolution de maillages." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://tel.archives-ouvertes.fr/tel-00916224.
Prouff, Antoine. "Correspondance classique-quantique et application au contrôle d'équations d'ondes et de Schrödinger dans l'espace euclidien." Electronic Thesis or Diss., université Paris-Saclay, 2024. https://theses.hal.science/tel-04634673.
Wave and Schrödinger equations model a variety of phenomena, such as propagation of light, vibrating structures or the time evolution of a quantum particle. In these models, the high-energy asymptotics can be approximated by classical mechanics, as geometric optics. In this thesis, we study several applications of this principle to control problems for wave and Schrödinger equations in the Euclidean space, using microlocal analysis.In the first two chapters, we study the damped wave equation and the Schrödinger equation with a confining potential in the euclidean space. We provide necessary and sufficient conditions for uniform stability in the first case, or observability in the second one. These conditions involve the underlying classical dynamics which consists in a distorted version of geometric optics, due to the presence of the potential.Then in the third part, we analyze the quantum-classical correspondence principle in a general setting that encompasses the two aforementioned problems. We prove a version of Egorov's theorem in the Weyl--Hörmander framework of metrics on the phase space. We provide with various examples of application of this theorem for Schrödinger, half-wave and transport equations
Joly, Romain. "Dynamique des EDP dissipatives." Habilitation à diriger des recherches, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00908118.
Herrera, Cristhiano da Costa. "Desenvolvimento e controle de circuitos microfluídicos." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-29012019-084425/.
The first stage of the project was to perform tests for controlled and optimized machining of borosilicate optical glass (BK7) by femtosecond laser. Parameters such as energy, number of overlapped pulses, and the focal position variation were investigated for a better extraction of material. Microchannels, microvalves, micropumps, mixers, reactors, heaters and other components were developed to compose applied microfluidic systems. Microchannels built on the surface of BK7 glass sealed by a polydimethylsiloxane (PDMS) sheet form the basis of the microfluidic circuits. The reagents flow control is done by pneumatic mini-valves controlled by an Arduino microcontroller through a Labview platform. This work shows the components developed and two microfluidic systems created. The first contains a microfluidic circuit capable of replicating enzyme-linked immunosorbent assays (ELISA) with a much lower cost of materials. The second has a microfluidic circuit for the production of NaYF4 fluorescent nanocrystals specially used as markers in images of biologic systems.
Haak, Bernhard Hermann. "Estimations quadratiques, calculs fonctionnels et applications." Habilitation à diriger des recherches, Université Sciences et Technologies - Bordeaux I, 2012. http://tel.archives-ouvertes.fr/tel-00771910.
Viard, Romain. "Dispositifs fluidiques de contrôle actif d’écoulements à base de microsystèmes magnéto-électro-mécanique (MMEMS) : (conception, réalisation, tests)." Thesis, Ecole centrale de Lille, 2010. http://www.theses.fr/2010ECLI0003/document.
This thesis starts with a study of aerodynamic flow control conditions by arrays of pulsed fluidic vortex generators. Detailed specifications are synthesised for the conception of low cost, sensors equipped, micro-actuators required to manage industrial scale active flow control experiments. Devices implementation is discussed to define relevant technical solutions.A packaged micro valve is modelled, fabricated and characterized. It is composed of a micro fluidic channel modulated by an annular membrane resonator made of PDMS. The membrane is controlled by different kinds of magnetic actuation. Fully controlled pulsed air jets are obtained in the frequency range [0; 500 Hz] with velocities up to 150 m/s. Arrays of these micro actuators are used in wind tunnel experiments to demonstrate the ability of pulsed jet to manage control on a wide range of classical separated flows. Reattachment is achieved under industrial flow conditions with improved fluidic yield compared to continuous jets.A mass flow meter constituted of a thermal sensor, a shear flow sensor and a Pirani pressure sensor, all of them built in a single fabrication step, is integrated in the micro-actuator. It allows in-situ characterization of the produced air jets.Finally, a fully satisfying demonstrator is obtained. Its sized is minimized through the use of a genetic algorithm
Wong, Eehern J. "Modeling and control of rapid cure in polydimethylsiloxane (PDMS) for microfluidic device applications." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61615.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 147-151).
Polydimethylsiloxane (PDMS) is an important thermosetting elastomer for microfluidic devices because it can replicate nano-scale features and form flexible membranes useful for microactuation. PDMS is used extensively in research environments because it is readily available and biocompatible. However, the prototyping process is too slow for volume manufacturing. The dominant rate limiting step is curing, and high temperature cures used to speed the curing process have adverse effects on the shape of the parts produced. This thesis examines the PDMS cure process and presents a methodology to intelligently design faster cure processes without compromising the quality of parts produced. The first part of this thesis applies statistical mechanics to relate the time evolution of cure with the modulus of elasticity. This enables mechanical testing strategies to be used in situ to monitor the extent of cure, which is important to determine the critical gel point and quantify when the cure process is complete. The gel point describes when PDMS first transitions from a liquid to a solid, and is important for modeling shrinkage and warpage. A novel heated microindentation setup is designed to monitor curing of thin PDMS films, and experimentally validate the theory. The second part of this thesis presents a model for final PDMS shrinkage and warpage using the gel point. Gelation is spatially and temporally distributed, and temperature at the gel point has a direct impact on the shrinkage and warpage observed. The model is validated with experimental data. Since gel temperature is the only parameter to affect shrinkage and curvature, the cure process is accelerated after the gel point without affecting dimensional quality. Increasing the process temperature immediately following gelation is indeed shown to decrease the current cure process time by a factor of five, while maintaining comparable quality. Tolerances on shrinkage and curvature can be used with these models to determine the gel temperatures required, and design multi-temperature processes that speed the cure process.
by Eehern J. Wong.
Ph.D.
Prüfert, Uwe. "Solving optimal PDE control problems : optimality conditions, algorithms and model reduction." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2016. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-204639.
Caubet, Fabien. "Détection d'un objet immergé dans un fluide." Phd thesis, Université de Pau et des Pays de l'Adour, 2012. http://tel.archives-ouvertes.fr/tel-00716902.
Bellet, Jean-Baptiste. "Identification par imagerie laser d'un objet dissimulé - Aspects mathématiques et numériques." Phd thesis, Ecole Polytechnique X, 2010. http://pastel.archives-ouvertes.fr/pastel-00549386.
Al-nasur, Sadeq J. "New Models for Crowd Dynamics and Control." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/30107.
Ph. D.
Mani, Skander. "Fundamentals Aspects of Crosslinking Control of PDMS Rubber at High temperatures using TEMPO Nitroxide." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/27984/27984.pdf.
The control of macromolecular structure has recently become an important topic of polymer science from both an academic and an industrial point of view. Indeed, free-radical crosslinking of Polydimethyl-vinylmethyl-siloxane (vinyl-PDMS) rubber by organic peroxide suffers from premature crosslinking at high temperatures, which is called scorching. Consequently, the basic aim of the investigations described in this thesis is to widen and explore the network topology–crosslinking kinetics relationships and find a novel way to control free-radical crosslinking chemistry and topological parameters of final PDMS networks. The work is primarily focused on the extensive study of the crosslinking control of PDMS rubber at high temperatures. A novel composition using 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) and dicumyl peroxide (DCP) for scorch delay and control of the final network topology of the PDMS has been proposed. The work specified in this thesis is therefore directed to find a proper [TEMPO]/[DCP] ratio provided the development of a new biphasic material such as PA12/PDMS blend type TPV (Thermoplastic Vulcanizated). For this purpose a new method based on the relationship between the kinetics of the macro-radicals coupling [Rcc(t)] was derived from a fundamental kinetic model and the viscoelastic changes of the complex shear modulus (G’(t) and G”(t)). The kinetic model takes into account the initiator (DCP) decomposition and the trapped PDMS macro-radicals in the presence of a radical scavenger such as TEMPO. As a main result, the rheological modelling shows that this new method accurately predicts the time variation of complex shear modulus at any temperature and [TEMPO]/[DCP] ratio. Interestingly, addition of TEMPO to the TPV novel composition provided the PA12/PDMS blend compatibilization in the dynamic process and gives a new material having a controlled structure and morphology. A better insight in understanding the blend composition and the morphology development relationships is aimed at.
Lissy, Pierre. "Sur la contrôlabilité et son coût pour quelques équations aux dérivées partielles." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://tel.archives-ouvertes.fr/tel-00918763.
Siska, David. "Numerical approximations of stochastic optimal stopping and control problems." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/2571.
Kachroo, Pushkin. "Optimal and Feedback Control for Hyperbolic Conservation Laws." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/28009.
Ph. D.
Winkelmann, Beate Maria. "Finite dimensional optimization methods and their application to optimal control with PDE constraints /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2005. http://wwwlib.umi.com/cr/ucsd/fullcit?p3205376.
Duca, Alessandro. "Analysis of the controllability of bilinear closed quantum systems." Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCD004/document.
The first part of the research is dedicated to the global exact controllability of the bilinear Schrödinger equation (BSE).We show how to construct a neighborhood of some eigenfunctions of the Dirichlet Laplacian where the local exact controllability is satisfied in a specific time. Then, for any couple of those eigenfunctions, we study how to construct controls and times such that the relative dynamics of (BSE) drives the first close to the second as much desired. Third, by gathering the two previous results, we define a dynamics steering eigenstates in eigenstates and we provide an explicit time required to reach the target.In the second part, we study the simultaneous global exact controllability in projection of infinitely many (BSE) and we prove the simultaneous local exact controllability in projection up to phases for any positive time. In the proof, we use different techniques from the Coron's return method usually adopted for those types of results. The main novelty of the work is the fact that it provides a set of conditions implying the validity of the result. Given any control field, one can verify if those assumptions are satisfied.The third part of the work treats the controllability of the bilinear Schrödinger equation (BSE) on compact graph. Considering (BSE) on such a complex structure is useful when one has to study the dynamics of wave packets on graph type model. We investigate assumptions on the graph and on the control field implying the well-posedness of (BSE) in suitable spaces that we characterize by providing peculiar interpolation features.Then, we provide the global exact controllability in those spaces by studying how the structure of the graph and the boundary conditions affect the result. We also provide examples of graphs and control fields so that the spectral assumptions of the global exact controllability are satisfied, e.g. star graphs, tadpole graphs and double-ring graphs.Afterwards, when the hypothesis for the global exact controllability fail, we define a weaker notion of controllability, the so-called “energetic controllability" which ensures the existence of a set of bounded states for which the exact controllability is verified. In other words, we prove the existence of energy levels in which it is possible to change the energy of the system.This technique allows to treat a large number of interesting problems. Indeed, for complex graphs, it is not possible to verify the spectral hypothesis of the global exact controllability. However, the energetic controllability allows to obtain interesting results only by looking for particular substructure contained in the graph
Hofer, Katharina [Verfasser]. "hp-finite elements for pde-constrained optimal control problems with focus on distributed control and fast solvers / Katharina Hofer." Bonn : Universitäts- und Landesbibliothek Bonn, 2016. http://d-nb.info/1119888816/34.
Infante, Acevedo José Arturo. "Méthodes et modèles numériques appliqués aux risques du marché et à l'évaluation financière." Phd thesis, Université Paris-Est, 2013. http://tel.archives-ouvertes.fr/tel-00937131.
Rosa, Reinaldo Lucas dos Santos. "Microválvulas destinadas ao controle do fluxo de líquidos em canais microfluídicos." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-27102017-075922/.
This work presents the physical modeling and implementation developed for different components necessary for the construction of electromagnetically actuating microvalves using a flexible membrane. Theoretical models were developed for describing the flow of fluids in microchannels, especially channels with rectangular transverse sections, routinely used as microchannels microfluidics. The model for the description of the deformation experienced by a PDMS microbridge was developed, allowing to estimate the elastic stiffness for various membranes developed in this work. In addition, a theoretical model was developed to study the forces produced by a microcoil with planar windings in squared spiral format, on a permanent magnet of NdFeB. Using the microchannel modeling, it was possible to estimate the hydraulic resistance offered by microchannels with micrometric dimensions, allowing to evaluate the relationship between inlet pressure and flow rate. It was possible to verify analytically that for the working range specified (flow rates of 0.2 to 6 mL/min for pressures from 0 to 30 kPa), channels with 1 cm in length and 200 ?m height should have a width varying in the range of 300 ?m to 500 µm in order to operate in the range of interest established in this study. Concerning the PDMS membrane, it was possible to estimate theoretically that a membrane with 2 cm in length, width of 2 mm and a thickness varying in the range of 1.6 to 2 mm, requires the implementation of a force in the range of 10.5 mN to 13 mN (range for the strength of action required) to obtain full deflection (250 µm). Evaluating Furthermore, using the theoretical model developed for the microcoils, it was possible to verify that a coil containing 36 windings, spacing of 80 µm, at a distance of 1 mm from the center of the magnet, and composed of 10 overlapping layers, it is possible to produce a force on a magnet of NdFeB up to 0.18 N in the regions from 3 mm to 10 mm away from the x-axis of the magnet, even at a height of 1 mm in relation to the plane xOy of magnet. The characterization of the responses associated with each component was made separately. The simulations showed similar results to those obtained experimentally, as evidenced from the errors obtained by relating the results of theoretical and experimental studies, especially for the microchannels. Microfluidic channels were manufactured with the following dimensions: length in the range of 1 to 4 cm, width in the range of 100 to 400 µm and heights in the range of 200 to 600 µm, 9 different devices were fabricated. It was observed that such microchannels were able to provide up to 1.41 mL/min to 0.8 kPa. The value of flow rate is within the expected range (0.2 to 6 mL/min) considering their application in chemical analysis, where the pressures provided can reach up to 60 kPa. Errors smaller than 5% for hydraulic resistance were obtained, indicating the validation of the theoretical model presented. Devices for fluidic switching with normally open and normally closed operation were fabricated and characterized with PDMS membranes and LTCC layers. Particularly a chamfer on the base of the ceramic substrates was proposed , in the region of contact with the membrane of PDMS, to better sealing the channel with the valve in a closed state. It has been observed that for a pressure of 5 kPa applied at the inlet of the valve, there was no leakage for the normally closed devices, and using a force around 1 N it is possible to achieve rates of liquid flow in the order of 0.45 mL/min, this being higher than the flow required for the intended application. Two assembling processes were developed for the microfluidic switching devices, one through the assembly of the PDMS membrane after LTCC sintering with the microcoil, and the other before the union between the switching device and the microcoil, requiring a step of welding between these components after the fabrication of membranes. Microcoils were manufactured and integrated with a NdFeB permanent magnet attached to a flexible membrane in contact with the channel. The coils were manufactured using dimensions of approximately 1 cm x 1 cm x 0.2 mm, containing 15 to 44 windings, with gaps ranging from 80 to 150 µm and the widths of the conductive wires in the range from 60 to 90 µm. The preliminary experimental results demonstrated that a planar coil (one layer, 36 windings, gap equal to 80 µm, cross section of 1 cm x 1 cm), subject to a potential difference of 1 Volt, is capable of producing a force of 0.02 N on the permanent magnet (located in the center at a z distance of 1 mm of the coil). This value indicates that at a voltage of 10 V it is possible to obtain a force of approximately 1 to 2 N for a coil with 10 layers, allowing for actuation of the microvalves developed.
Pearson, John W. "Fast iterative solvers for PDE-constrained optimization problems." Thesis, University of Oxford, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.581405.