Дисертації з теми "Formulation Inverse"
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Dridi, Wafa. "Influence de la formulation sur l'oxydation des huiles végétales en émulsion eau-dans-huile." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0102/document.
Повний текст джерелаOxidation is ubiquitous in lipids and causes degradation of organoleptic and nutritional qualities of foods. Lipid oxidation depends on various parameters (temperature, light, transition metals, lipid dispersion state …) that have to be controlled during food processing and storage. In this context, lipid oxidation was followed by measuring the content of primary oxidation products, for lipids in bulk phase and in water-in-oil emulsions. Different edible oils were chosen for their contents of α-linolenic acid (18: 3 n-3). Emulsions were formulated at varying polyglycerol polyricinoleate (PGPR)/distilled monoglycerides concentration ratios (surfactant ratio), with or without the presence of pro-oxydant metals or chelators. In all experiments, the aqueous volume fraction (40%) and the droplet mean diameter (1 μm) remained constant. Besides this study, an innovative and rapid method based on differential microcalorimetry was developed for monitoring the kinetics of lipid oxidation. The oxidability of the studied oils was related to their content in α-linolenic acid according the following order: linseed oil> camelina oil> rapeseed oil> olive oil. The rate of lipid oxidation increased with the iron sulfate concentration in the water phase. The iron valence or the replacement of iron by copper had no significant impact on the oxidation kinetics. However, both the chemical nature of the counter ion (molecular weight, chelating power) and the proportion of PGPR used to stabilize the emulsions were influential factors. On the whole, our results suggest that surfactants at the water-oil interface do not prevent pro-oxidant species to interact with lipids in the continuous phase but that their organization at the interface is a key parameter for controlling lipid oxidation
Gatina, Jean-Claude. "Contacts de corps élastiques effets tangentiels et normaux, formulation et résolution des problèmes inverse et direct /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37611048t.
Повний текст джерелаLouati, Kaouthar. "Modèles Mathématiques pour l'Inspection Nondestructive des Pipelines." Phd thesis, Ecole Polytechnique X, 2006. http://tel.archives-ouvertes.fr/tel-00125751.
Повний текст джерелаOn jette les bases mathématiques de ces différentes méthodes et on présente quelques tests numériques qui montrent leur efficacité.
Notre approche rentre dans la stratégie asymptotique développée au CMAP pour la résolution des problèmes inverses d'une manière robuste et stable. On exploite l'existence d'un petit paramètre (la mesure de Hausdorff de la partie corrosive) pour extraire des données la localisation de la partie corrosive et estimer son étendue. Le tout, d'abord, à travers des formules asymptotiques des mesures dépendantes du petit paramètre, rigoureusement établies à l'aide de la méthode des équations intégrales, et ensuite, par le biais de nouveaux algorithmes non-itératifs d'inversion. La plupart de ces algorithmes sont de type MUSIC (multiple signalclassification).
Le dernier chapitre est indépendant des trois premiers. il est consacré à la reconstruction de la forme d'un objet perturbé connaissant le champ lointain électrique ou acoustique. On développe pour le cas acoustique et électrique une relation linéarisée entre le champ lointain, résultant des données sur le bord de conditions de Dirichlet comme paramètre, et la forme de la structure perturbée comme variable. Cette relation nous ouvre la voie à la reconstruction
des coefficients de Fourier de la perturbation et nous aide à la reconstruction des coefficients de Fourier de la perturbation ce qui nous mène à formuler un développement asymptotique complet de
l'opérateur Dirichlet-Neumann.
Panchea, Adina. "Inverse optimal control for redundant systems of biological motion." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2050/document.
Повний текст джерелаThis thesis addresses inverse optimal control problems (IOCP) to find the cost functions for which the human motions are optimal. Assuming that the human motion observations are perfect, while the human motor control process is imperfect, we propose an approximately optimal control algorithm. By applying our algorithm to the human motion observations collected for: the human arm trajectories during an industrial screwing task, a postural coordination in a visual tracking task and a walking gait initialization task, we performed an open loop analysis. For the three cases, our algorithm returned the cost functions which better fit these data, while approximately satisfying the Karush-Kuhn-Tucker (KKT) optimality conditions. Our algorithm offers a nice computational time for all cases, providing an opportunity for its use in online applications. For the visual tracking task, we investigated a closed loop modeling with two PD feedback loops. With artificial data, we obtained consistent results in terms of feedback gains’ trends and criteria exhibited by our algorithm for the visual tracking task. In the second part of our work, we proposed a new approach to solving the IOCP, in a bounded error framework. In this approach, we assume that the human motor control process is perfect while the observations have errors and uncertainties acting on them, being imperfect. The errors are bounded with known bounds, otherwise unknown. Our approach finds the convex hull of the set of feasible cost function with a certainty that it includes the true solution. We numerically guaranteed this using interval analysis tools
Alvarez, Aramberri Julen. "hp-Adaptive Simulation and Inversion of Magnetotelluric Measurements." Thesis, Pau, 2015. http://www.theses.fr/2015PAUU3056/document.
Повний текст джерелаThe magnetotelluric (MT) method is a passive exploration technique that aims at estimating the resistivity distribution of the Earth's subsurface, and therefore at providing an image of it. This process is divided into two different steps. The first one consists in recording the data. In a second step, recorded measurements are analyzed by employing numerical methods. This dissertation focuses in this second task. We provide a rigorous mathematical setting in the context of the Finite Element Method (FEM) that helps to understand the MT problem and its inversion process. In order to recover a map of the subsurface based on 2D MT measurements, we employ for the first time in Mts a multi-goal oriented self adaptive hp-Finite Element Method (FEM). We accurately solve both the full formulation as well as a secondary field formulation where the primary field is given by the solution of a 1D layered media. To truncate the computational domain, we design a Perfectly Matched Layer (PML) that automatically adapts to high-contrast material properties that appear within the subsurface and on the air-ground interface. For the inversion process, we develop a first step of a Dimensionally Adaptive Method (DAM) by considering the dimension of the problem as a variable in the inversion. Additionally, this dissertation supplies a rigorous numerical analysis for the forward and inverse problems. Regarding the forward modelization, we perform a frequency sensitivity analysis, we study the effect of the source, the convergence of the hp-adaptivity, or the effect of the PML in the computation of the electromagnetic fields and impedance. As far as the inversion is concerned, we study the impact of the selected variable for the inversion process, the different information that each mode provides,and the gains of the DAM approach
Buchert, Pascale. "Polymerisation d'un monomere cationique, le chlorure de methacryloxyethyltrimethylammonium, en microemulsion inverse : formulation, caracterisation et comportement rheologique des microlatex formes." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13106.
Повний текст джерелаBuchert, Pascale. "Polymérisation d'un monomère cationique, le chlorure de méthacryloxyéthyltriméthylammonium, en microémulsion inverse formulation, caractérisation et comportement rhéologique des microlatex formés /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376122803.
Повний текст джерелаAdde, Geoffray. "Méthodes de traitement d'image appliquées au problème inverse en magnéto-électro-encéphalographie." Marne-la-vallée, ENPC, 2005. https://pastel.archives-ouvertes.fr/pastel-00001593.
Повний текст джерелаClément, François. "Une formulation en temps de parcours par migration pour la détermination des vitesses de propagation acoustique à partir de données sismiques bi-dimensionnelles." Paris 9, 1994. http://www.theses.fr/1994PA090033.
Повний текст джерелаThe aim of this thesis is the implantation of a method, wich consists in a migration-based traveltime formulation, allowing the automatic detremination of the velocities from 2D seismic data. This approach interprets itself as a duality method applied ti the usual minimisation problem of the least-square error between data and predicted measures. The three chapters of the first part deal with the construction of basic tools : finite differences numerical simulation of the acoustic wave equation, separation of the propagation and reflection effects by representation of the acoustic parameters on a multiscaled basis and quantitative migration through a preconditionning of the usual migration operator obtained via a gradient calculation. The four chapters of the second part deal with the time formulation itself : motivations and key ideas, description of the new forward model, computation and visualisation of the gradients of the new cost functionand results of the minimisation of this cost function. Numerical illustrations are obtained with synthetic data wich are computed from a model with a simple structure but with important lateral velocity variations. THe results of the inversion of these data are very satisfying as they are obtained by a local (Quasi-Newton-based) minimisation method from a very poor initial point (constant)
Park, Won-Kwang. "Diffraction inverse par des inclusions minces et des fissures." Phd thesis, Ecole Polytechnique X, 2009. http://pastel.archives-ouvertes.fr/pastel-00004834.
Повний текст джерелаLanglois, Raphaël. "Non-parametric evaluation of stress fields for history-dependent materials : Formulation, Validation and Appications." Electronic Thesis or Diss., Ecole centrale de Nantes, 2023. http://www.theses.fr/2023ECDN0002.
Повний текст джерелаIn recent years, new paradigms havebeen proposed to identifiy stress fields withoutany postulate on the form of the constitutive relationfor elastic materials from full-field kinematicmeasurements. These methods allow the evaluationof stress fields on geometries which usuallyrequire the a priori formulation of a constitutivemodel.The present work is an extension of theso-called Data-Driven Identification proposed byLeygue et al. (2018) to history-dependent materials.The proposed extension is validated witha test on a complex geometry sample for a lowcarbonsteel exhibiting Piobert–Lüders instabilitieswhere classical methodes such as « Finite-Element Method Updating » cannot be reasonablyemployed.Second, fatigue crack propagation tests areanalysed. A meshing strategy is proposed to accountfor the free boundaries introduced by thepropagating crack in a strain measurement by« Digital Image Correlation ». The stress fieldsat the crack tip are estimated for various cracklengths and loadings to highligth interactions betweenthe crack and the geometric features of thesamples. Finally, using minimal hypotheses theplastic strains are estimated and analysed
Romero, Morante Carolina. "Etude d'un inhibiteur de dépôts en émulsion inverse eau/huile : formulation et mécanismes de rétention sur des substrats représentatifs des milieux pétroliers." Besançon, 2006. http://www.theses.fr/2006BESA2068.
Повний текст джерелаAdde, Geoffray. "Méthodes de Traitement d'Image Appliquées au Problème Inverse en Magnéto-Electro-Encéphalographie." Phd thesis, Ecole des Ponts ParisTech, 2005. http://pastel.archives-ouvertes.fr/pastel-00001593.
Повний текст джерелаTaillandier, Cédric. "Formulation de la tomographie des temps de première arrivée à partir d'une méthode de gradient : un pas vers une tomographie interactive." Phd thesis, École Nationale Supérieure des Mines de Paris, 2008. http://pastel.archives-ouvertes.fr/pastel-00004850.
Повний текст джерелаDemirci, Nagehan. "Formulation And Implementation Of A Fractional Order Viscoelastic Material Model Into Finite Element Software And Material Model Parameter Identification Using In-vivo Indenter Experiments For Soft Biological Tissues." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614080/index.pdf.
Повний текст джерелаoptimization toolbox. After the superiority of the fractional order material model compared to integer order material models has been shown, the linear fractional order material model is extended to its nonlinear counterpart in finite deformation regime. The material model developed is assumed to be isotropic and homogeneous. v A user-subroutine is developed for the material model formulated to implement it into the commercial finite element software Msc.Marc 2010. The user-subroutine developed is verified by performing a small strain finite element analysis and comparing the results obtained with linear viscoelastic counterpart of the model on MATLAB®
. Finally, the unknown coefficients of the fractional order material model are identified by employing the inverse finite element method. A material parameter set with an amount of accuracy is determined and the material model with the parameters identified is capable of simulating the three different indentation test protocols, i.e., &ldquo
relaxation&rdquo
, &ldquo
creep&rdquo
and &ldquo
cyclic loading&rdquo
protocols with a good accuracy.
Arhab, Slimane. "Profilométrie optique par méthodes inverses de diffraction électromagnétique." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4321/document.
Повний текст джерелаOptical profilometry is a nondestructive and fast noncontact surface metrology technique. In this thesis, we have tackled this issue with inverse scattering electromagnetic methods and in an Optical Digital Tomographic Microscopy (ODTM) configuration. The surface is probed with illuminations under several incidence angles; the measure of far scattered field amplitude and phase constitutes the problem data. Surface profiles have been reconstructed using different scattering models among which an approximate theory based on single scattering and paraxiality. The lateral resolution of this technique and classical profilometric approaches is limited by the so-called Abbe-Rayleigh's criterion defined out of the numerical aperture for illumination and field detection. In order to overpass this resolution limit, we have developed a regularized iterative Newton-Kantorovitch's method. The scattering operator is rigorously modelized with the method of moments, that is a numerical solution of boundary integral equations, and its Fréchet derivative adjoint states expression is deduced from the reciprocity theorem. For one-dimensional metallic surfaces, our method succeeds in inverting from synthetic data very rough surfaces with the resolutions beyond the Abbe-Rayleigh's criterion. The performance of this technique and inversion conditions clearly differ from one polarization to the other : in the TM case, interactions at longer distance than in the TE case improve yet the resolution. This work includes also an experimental validation of our inverse model on grooves in indium phosphure substrate at 633 nm
Aguilera, Miguel Antonio. "Transfert de matière dans les milieux complexes. Ingénierie inverse : de la propriété d’usage au matériau." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0046.
Повний текст джерелаIn the past decade, the growing use of numerous novel technologies as controlled-delivery systems has prompted a costly trial-and-error development of new and effective systems. In order to facilitate a more rational design and optimization, facing the set of existing possibilities, any solution that could semiautomate the product development would bring precious help to the users (formulation scientists and educators). This would facilitate the essential importance of choosing the right materials for the correct application. In this thesis, a long-term project concerning a reverse engineering is proposed, starting from a final usage property (controlled release), the global target is to develop a product design methodology which allows us to determine the optimal features of a formulation to prepare: phases in presence, composition, interface type, size and distribution of current objects, phase equilibrium, diffusion within phases and evolutionary character of the material. Considering a convenience example of structured-dispersed system: highly concentrated emulsions, the design problem has been decomposed into a hierarchical sequence of subproblems or boxes, combining constitutive models that estimate the active ingredient mass transport as a function of formulation parameters and computer-aided techniques such as molecular modeling for volume/area of molecules, or UNIFAC models for equilibria predictions as well as for mixture viscosities estimations. A subsequent full factorial design of virtual experiments has allowed to obtain a quantitative description of the release depending on the model parameters, and a principal component analysis has assessed the importance of the variables. Using a cartography focused on three surfactants (SPAN 80, PGPR and BRIJ 93), four oils (dodecane, hexadecane, isopropyl myristate and isopropyl palmitate) and mandelic acid as an active ingredient, the ab-initio physicochemical model has been experimentally validated. Results show that the mechanistic model consistently predicts the diffusion of the active ingredient from emulsions to a release medium in perfect sink conditions. This reverse engineering approach is showing to be of very high interest in the domain of formulation by allowing fast and robust screening preliminary studies on a broad range of components as well as precise and rigorous prediction tools to optimize controlled release from an identified system. It is fully recommended to implement its extensions to other similar disperse systems
Nehmeh, Mohamad. "Eco-conception de solvants de substitution de l'hexane pour l'extraction d'huile issue de tourteaux oléagineux par une approche d'ingénierie inverse." Electronic Thesis or Diss., Université de Toulouse (2023-....), 2024. http://www.theses.fr/2024TLSEP062.
Повний текст джерелаFollowing an initial vegetable oil extraction through oilseed pressing, valuable residual oil persists within the oilseed cake, necessitating a further solvent extraction process. Hexane is currently the predominant solvent employed industrially for oilseed oil extraction. Despite its favourable characteristics such as lipid selectivity and ease of separation from oil through distillation, concerns regarding toxicity and non-renewable sourcing have prompted investigations into its replacement. This research aims to identify novel solvents for the selective extraction of oil from oilseeds that are healthier, safer, and environmentally sustainable, including bio-based solvents.To achieve this objective, a reverse engineering approach based on High Throughput Screening (HTS) and Computer Aided Molecular Design (CAMD) is employed to design optimal alternatives tailored to specific application requirements. The reverse engineering process began by defining the target values for key physicochemical properties (e.g., boiling point, flash point) of existing solvents used in oil extraction. Subsequently, molecular structures aligning with these targets were sought among thousands of solvents using the CAMD tool IBSS (InBioSynSolv). Specifically, for each and every molecule, the properties are predicted through group contribution models and compared against technical specifications, safety criteria, and environmental and health considerations. Further refinement of the candidate solvents generated by IBSS involved investigating the affinity between the identified solvent candidates and the target solutes within the cake, by comparing their σ-profile (determined using the COSMO-RS tool) and calculating the thermodynamic equilibrium. This methodology, coupling various modelling tools and industrial criteria, enabled an effective selection of a handful of candidates based on their selectivity towards lipids. Finally, experimental validation was conducted across various scales to corroborate the efficiency of the alternative solvents
Miltiadou, Panayiotis. "Inverse analysis formulations for cathodic protection systems." Thesis, Brunel University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392074.
Повний текст джерелаParuta, Tuarez Emilio Alberto. "Émulsions inverses très concentrées : formulation, comportement rhéologique et modélisation." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL008N/document.
Повний текст джерелаThis thesis deals with the study of the influence of formulation on the rheological behavior of highly concentrated reverse emulsions. We used an original approach consisting in representing the elastic modulus (G’) of these emulsions on a formulation-composition bidimensional map to study, in particular, the effect of the so-called optimum formulation. Two major effects are observed in relation to this one: emulsions prepared at HLB=10, i.e. at the proximity of optimum value (HLB=10.5) present values of G’ remarkably lower than those at other formulations, while at a certain distance (HLB=7.7) the values of G’ are higher in comparison to others formulations. This last particular HLB matches with the occurrence of a maximum stability and a minimum drop size of dispersion. Highly concentrated emulsions being generally opaque and fragile, the analysis of incoherent polarized steady light transport, that does not imply any dilution, has been used as an alternative method to classical techniques to determine the average film thickness (h). The average drop size (R) has then to be determined from a geometrical model linking it to the average film thickness (h), to the dispersed phase volume fraction (f) and to a geometrical factor (f9) that takes into account the polyhedral shape of the drops. Hence, a modified expression of the model proposed by Mougel et al. (2006) has been established to model the elastic modulus (G’) by relating it to the average drop size (R), the interfacial tension (s) and the dispersed phase volume fraction (f)
Chabchoub, Mohamed-Amine. "Méthodes Energétiques Simplifiées Inverses : formulations et applications." Phd thesis, Ecole Centrale de Lyon, 2010. http://tel.archives-ouvertes.fr/tel-00916927.
Повний текст джерелаAcevedo, Nancy Isabel Alvarez. "Uma formulação explícita matricial para problemas inversos de transferência radiativa em meios participantes homogêneos unidimensionais." Universidade do Estado do Rio de Janeiro, 2006. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=372.
Повний текст джерелаA formulação explícita matricial desenvolvida nesta tese de doutorado foi proposta visando ser uma alternativa na solução de Problemas Inversos de estimativa de propriedades radiativas em meios participantes homogêneos unidimensionais usando a Equação de Transferência Radiativa para modelar a interação da radiação com o meio participante. A equação de transporte é formulada em forma matricial e o domínio angular é discretizado usando conceitos do método de ordenadas discretas e a expansão da função de fase do espalhamento anisotrópico em uma série de polinômios de Legendre. A formulação proposta consiste em uma formulação explícita para o problema inverso. Um arranjo apropriado das condições de contorno prescritas (fluxos incidentes) e dos fluxos emergentes nos contornos de uma placa permitem o cálculo direto do operador de transmissão, do operador albedo e do operador de colisão. A partir do operador de colisão calculado são obtidos os valores estimados dos coeficientes de extinção total e de espalhamento. São apresentadas as formulações para problemas em regime estacionário e em regime transiente, bem como os resultados para alguns casos-teste.
The explicit matrix formulation developed in the present thesis has been proposed as an alternative for the solution of Inverse Problems for radiative properties estimation in one-dimensional homogeneous participating media using Radiative transfer equation for the modeling of the radiation interaction with the participating medium. This transport equation is formulated in a matrix form and the angular domain is discretized using concepts of the discrete ordinates methods and the expansion of the function of phase function of anisotropic scattering in a series of Legendre polynomial. The formulation proposed consists on an explicit formulation for the inverse problem. An adequate assembly of the prescribed boundary conditions (incidents flux) and of the emerging flux at the boundaries of the slab allows the direct computation of the transmission, albedo and collision operators. From the computed collision operator estimated values for total extinction and scattering coefficients are obtained. The formulations for steady state and transient situations are presented, as well as test case results.
Filho, Sylvio Celso Tartari. "Modelagem e otimização de um robô de arquitetura paralela para aplicações industriais." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3152/tde-07122006-151723/.
Повний текст джерелаThis work is about the study of parallel architecture robots, focusing in modeling and optimization. No physical prototypes were built, although the virtual models can help those willing to do so. After searching for an application that could benefit from the use of a parallel robot, another search was made, this time for the right architecture type. After selecting the architecture, the next step was the kinematics and dynamics analysis. The dynamics model is developed using the Newton ? Euler method. A virtual simulator was also developed in MATLAB 6.5 environment. The simulator?s main purpose was to demonstrate that the methods applied were correct and efficient, so it has several features such as linear and circular interpolations, capacity to use multiple coordinate systems and others. After finishing the simulator, an algorithm to calculate the machine workspace was added. The algorithm receives as input some desired requirements regarding the manipulator pose and then calculates the workspace, taking into consideration imposed constraints. Lastly, algorithms capable to measure the manipulator?s performance regarding to its actuator and end-effector force relationship were also incorporated into the simulator that calculates the machine?s force ellipsoid during any movement, for each desired workspace point. For the optimization procedures, some previously developed tools were used, so that the resulting model was capable to respect some workspace constraints regarding size and shape, but also maintaining the best performance possible inside this volume.
Helifa, Bachir. "Contribution à la simulation du CND par courants de Foucault en vue de la caractérisation des fissures débouchantes." Nantes, 2012. http://archive.bu.univ-nantes.fr/pollux/show.action?id=4d9f6caf-4c86-49ca-ba1b-9b4aeca65049.
Повний текст джерелаThe work of the present thesis falls within the field of Non Destructive Testing (NDT) by eddy current (EC) in its experimental and modeling aspects. Its main purpose is the development of an evaluation strategy and the elaboration of software and hardware tools for better analysis of signals from an eddy current sensor for the characterization of surface cracks in "critical" parts of conducting materials. It fits into the general framework for the characterization of cracks by eddy currents. In this context and in order to place the work in a more general framework, we consider cracks containing material that unidentified electrical conductivity and (or) magnetic permeability with an unknown coating thickness. Direct models in 2D and 3D finite element magnetodynamic formulation using magnetic vector and electric scalar potentials deduced from Maxwell equations are developed for modeling the system (material + crack + coil). Simplex and neural networks algorithms are developed for solving the inverse problem in order to obtain a complete characterization of the surface crack. We validate the developed models (direct and reverse) by comparing data obtained from a set of laboratory experiments, using known coils and standard parts with clearly identified cracks, which allows the determination of the morphology of the surface crack : position, shape and dimensions. Finally, and based on the developed approaches, we establish a control strategy for a complete characterization of surface cracks
Delaunay, Tiphaine. "Adaptative observers for wave equations and associated discretizations : formulations and analysis." Electronic Thesis or Diss., Institut polytechnique de Paris, 2023. http://www.theses.fr/2023IPPAX120.
Повний текст джерелаThe context of this thesis is the study of inverse problems for wave propagation phenomena from a control theory perspective, more specifically using observation theory. Our goal is to formalize, analyze, and discretize strategies called sequential in data assimilation, where measurements are taken into account as they become available. The resulting system, called an observer (or a sequential estimator), stabilizes on the observed trajectory hence reconstructs the state and possibly some unknown parameters of the system. Here we focus in particular on source reconstruction on the right-hand side of our wave equation, an estimation problem intermediate in complexity between state estimation (or initial condition estimation) and the more general problem of parameter identification. In this context, we propose to define in a deterministic framework in infinite dimension a so-called Kalman estimator that sequentially estimates the source term to be identified. Using dynamic programming tools, we show that this sequential estimator is equivalent to the minimization of a functional. This equivalence allows us to propose convergence analysis under observability conditions. We then demonstrate observability inequalities for different source types by combining functional analysis, multiplier methods, and Carleman estimates. In particular, these inequalities inform us about the ill-poseness nature of the inverse reconstruction problems we study and allow us to quantify the degree of ill-posedness hence to propose adapted regularizations. In particular, we compare an invert-and-regularize strategies as opposed to regularize-to-invert. Concerning discretization issues and their analysis, we defend the idea of redefining these observers associated with the minimization of the functional once the direct model has been discretized. This discretize-then-optimize approach is advantageous for the analysis compared to optimize-then-discretize approach. Nevertheless, the observability inequalities need to be extended to discretized systems. In particular, in this context, we extend uniform exponential stabilization results to the discretization for high-order finite element discretizations of the wave equation
Veyssiere, Julie. "Étude comportementale de la spadine et de ses analogues : un nouveau concept d'antidépresseur." Thesis, Nice, 2014. http://www.theses.fr/2014NICE4004/document.
Повний текст джерелаDepression is a devastating psychiatric disorder which affects about 20% of the population. In 2006 our team demonstrated the involvement of TREK-1, a potassium channel, in this pathology, and that its inhibition has led to a depression’s resistant phenotype. The search of TREK-1 inhibitors, a potential antidepressant, has led to the discovery of spadin. Spadin has, after only a four day treatment, similar efficacy than classical antidepressants which require about three weeks of treatment to produce their therapeutic effects. My work was firstly focused on the potential side effects of spadin. Indeed, TREK- 1’s activation has beneficial effects in many pathophysiologies (ischemia, epilepsy, pain). Its inhibition by spadin could generate significant adverse effects. The use of animal models has allowed us to confirm that spadin has no side effects related to TREK-1 channel’s inhibition. The specificity of spadin has been demonstrated since it has no effect on other potassium channels belonging to the K2P family. My work was also to study the effects of spadin in two mice models of depression, a genetic model and an induced model. In both cases, spadin shows a specific antidepressant effect in different behavioral tests of depression. The last part of my work was focused on the development of spadin’s analogs in order to improve the affinity and in vivo efficiency. We also developed, in collaboration with the MedinCell society, a polymer formulation for the constant and prolonged release of the selected analog. This formulation will be administered as a single injection treatment for three to four weeks, solving the problems caused by non respected medication by patients
Alvarez, Solano Oscar Alberto. "Émulsions inverses trés concentrées : influence du procédé et de la formulation sur leurs propriétés rhéologiques." Vandoeuvre-les-Nancy, INPL, 2006. http://docnum.univ-lorraine.fr/public/INPL/2006_ALVAREZ_SOLANO_O_A.pdf.
Повний текст джерелаCe travail concerne la préparation d'émulsions inverses très concentrées à l'aide d'un procédé discontinu. Le procédé d'émulsification peut être décomposé en deux étapes principales, une étape d'incorporation et une étape d'homogénéisation, cette dernière étape étant de loin la plus énergivore. Trois lois d'échelle cohérentes ont été obtenues indépendamment au terme du procédé d'émulsification, qui concernent une relation entre le module élastique et l'énergie consommée par unité de volume (G'~Ev0,6), une relation entre un rayon moyen des gouttes et l'énergie consommée par unité de volume (Rm ~ EV-0. 3) et enfin une relation entre le module élastique et un rayon moyen des gouttes (G' ~ Rm-2). Cette dernière relation est en désaccord avec le modèle de PRINCEN. Un modèle structural semi-empirique basé sur l'idée que l'élasticité de ces émulsions très concentrées a pour origine les forces de Van der Waals a été proposé qui conduit à une dépendance en accord avec nos résultats expérimentaux. L'étude de l'évolution temporelle du rayon moyen des gouttes vers un état de pseudo-équilibre qui ne dépend que de la concentration en tensioactif suggère que le processus initial de déstabilisation est lié à un phénomène de perméation de la phase dispersée
Alvarez, Solano Oscar Alberto Choplin Lionel. "Émulsions inverses trés concentrées influence du procédé et de la formulation sur leurs propriétés rhéologiques /." Vandoeuvre-les-Nancy : INPL, 2006. http://www.scd.inpl-nancy.fr/theses/2006_ALVAREZ_SOLANO_O_A.pdf.
Повний текст джерелаThibaut, Muriel. "Géométrie des surfaces de faille et dépliage 3D : (méthodes et applications)." Phd thesis, Université Joseph Fourier (Grenoble), 1994. http://tel.archives-ouvertes.fr/tel-00745509.
Повний текст джерелаByamungu, Cirhuza Alain. "The formulation and validation of PV inverter efficiency under South Africa climate conditions." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2823.
Повний текст джерелаIn photovoltaic power systems, the DC/AC conversion efficiency depends on weather conditions causing PV inverters to operate under fluctuating input power from PV modules. The peak efficiency stated by the inverter manufacturers are often used by project designers to estimate how much power PV plants can produce. However, the varying nature of the DC input power to the inverters, occasioned by varying irradiation and temperature, leads to deviations of the actual efficiency from the peak efficiency. Literature surveys prove that inverter efficiencies must be evaluated against local irradiation profiles to get more precise annual energy yield estimations, since meteorological conditions and solar irradiation profiles vary from one site to another around the planet.
Kim, Hoan-Kee. "Multi-scale nonlinear constitutive models using artificial neural networks." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22613.
Повний текст джерелаCommittee Chair: Rami M Haj-Ali; Committee Member: Arash Yavari; Committee Member: Donald W. White; Committee Member: Erian Armanios; Committee Member: Kenneth M. Will.
Görke, Uwe-Jens, Anke Bucher, and Reiner Kreißig. "Zur Numerik der inversen Aufgabe für gemischte (u/p) Formulierungen am Beispiel der nahezu inkompressiblen Elastizität bei großen Verzerrungen." Universitätsbibliothek Chemnitz, 2007. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200702023.
Повний текст джерелаHeintz, Juliette. "Systemic approach and decision process for sustainability in chemical engineering : Application to computer aided product design." Thesis, Toulouse, INPT, 2012. http://www.theses.fr/2012INPT0087/document.
Повний текст джерелаIn a context where environmental issues are increasingly taken into account, the chemical related industry faces situations imposing a chemical product substitution. Computer aided molecular design methods, which consist in finding molecules satisfying a set of constraints, are well adapted to these situations. Using a systemic analysis of the needs and uses linked to this context, we develop a computer aided product design tool implementing a genetic algorithm. It is able to explore a wider solution space thanks to a flexible molecular framework. Besides, by allowing a very flexible setting of the problem to be solved, it enables the search of molecules sourced from renewable resources. Based on concepts from system and enterprise engineering, we formalize a decision making process dedicated to the product substitution in an industrial context. This multi-criteria decision process includes the phases of the requirements definition, of the generation of alternative solutions, of the selection of the best alternative and of the product application. It uses a model driven approach and decision making techniques that guaranty an operational alignment in addition to the strategic alignment across the chemical enterprise. Through a case study, we expose how the combination of our computer aided product design tool and our decision making process enables an environmentally compliant approach of product substitution which is both efficient and in adequacy with enterprise context
Veyssiere, Julie. "Étude comportementale de la spadine et de ses analogues : un nouveau concept d'antidépresseur." Electronic Thesis or Diss., Nice, 2014. http://theses.unice.fr/2014NICE4004.
Повний текст джерелаDepression is a devastating psychiatric disorder which affects about 20% of the population. In 2006 our team demonstrated the involvement of TREK-1, a potassium channel, in this pathology, and that its inhibition has led to a depression’s resistant phenotype. The search of TREK-1 inhibitors, a potential antidepressant, has led to the discovery of spadin. Spadin has, after only a four day treatment, similar efficacy than classical antidepressants which require about three weeks of treatment to produce their therapeutic effects. My work was firstly focused on the potential side effects of spadin. Indeed, TREK- 1’s activation has beneficial effects in many pathophysiologies (ischemia, epilepsy, pain). Its inhibition by spadin could generate significant adverse effects. The use of animal models has allowed us to confirm that spadin has no side effects related to TREK-1 channel’s inhibition. The specificity of spadin has been demonstrated since it has no effect on other potassium channels belonging to the K2P family. My work was also to study the effects of spadin in two mice models of depression, a genetic model and an induced model. In both cases, spadin shows a specific antidepressant effect in different behavioral tests of depression. The last part of my work was focused on the development of spadin’s analogs in order to improve the affinity and in vivo efficiency. We also developed, in collaboration with the MedinCell society, a polymer formulation for the constant and prolonged release of the selected analog. This formulation will be administered as a single injection treatment for three to four weeks, solving the problems caused by non respected medication by patients
Mauro, Paolo. "THE DYNAMIC OLIGOPOLISTIC MARKET EQUILIBRIUM PROBLEM: THE VARIATIONAL FORMULATION, THE LAGRANGEAN FORMULATION, THE INVERSE PROBLEM AND COMPUTATIONAL MATTERS." Tesi di dottorato, 2013. http://www.fedoa.unina.it/9134/1/Tesi%20di%20Dottorato%20di%20Ricerca%20di%20Paolo%20Mauro%20PDFA.pdf.
Повний текст джерелаBabaniyi, Olalekan. "Stabilized variational formulation for direct solution of inverse problems in heat conduction and elasticity with discontinuities." Thesis, 2016. https://hdl.handle.net/2144/14640.
Повний текст джерелаFeroj, Md Jamil. "On use of inhomogeneous media for elimination of ill-posedness in the inverse problem." 2014. http://hdl.handle.net/1993/23525.
Повний текст джерелаDasgupta, Bhaskar. "The Stewart Platform Manipulator : Dynamic Formulation, Singularity Avoidance And Redundancy." Thesis, 1996. https://etd.iisc.ac.in/handle/2005/1712.
Повний текст джерелаDasgupta, Bhaskar. "The Stewart Platform Manipulator : Dynamic Formulation, Singularity Avoidance And Redundancy." Thesis, 1996. http://etd.iisc.ernet.in/handle/2005/1712.
Повний текст джерелаKulkarni, Raghavendra B. "Inverse problems solution using spectral finite element methods." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5471.
Повний текст джерелаFinke, Stefan. "Conventional and Reciprocal Approaches to the Forward and Inverse Problems of Electroencephalography." Thèse, 2012. http://hdl.handle.net/1866/8746.
Повний текст джерелаThe inverse problem of electroencephalography (EEG) is the localization of current sources within the brain using surface potentials on the scalp generated by these sources. An inverse solution typically involves multiple calculations of scalp surface potentials, i.e., the EEG forward problem. To solve the forward problem, models are needed for both the underlying source configuration, the source model, and the surrounding tissues, the head model. This thesis treats two distinct approaches for the resolution of the EEG forward and inverse problems using the boundary-element method (BEM): the conventional approach and the reciprocal approach. The conventional approach to the forward problem entails calculating the surface potentials starting from source current dipoles. The reciprocal approach, on the other hand, first solves for the electric field at the source dipole locations when the surface electrodes are reciprocally energized with a unit current. A scalar product of this electric field with the source dipoles then yields the surface potentials. The reciprocal approach promises a number of advantages over the conventional approach, including the possibility of increased surface potential accuracy and decreased computational requirements for inverse solutions. In this thesis, the BEM equations for the conventional and reciprocal approaches are developed using a common weighted-residual formulation. The numerical implementation of both approaches to the forward problem is described for a single-dipole source model. A three-concentric-spheres head model is used for which analytic solutions are available. Scalp potentials are calculated at either the centroids or the vertices of the BEM discretization elements used. The performance of the conventional and reciprocal approaches to the forward problem is evaluated for radial and tangential dipoles of varying eccentricities and two widely different skull conductivities. We then determine whether the potential advantages of the reciprocal approach suggested by forward problem simulations can be exploited to yield more accurate inverse solutions. Single-dipole inverse solutions are obtained using simplex minimization for both the conventional and reciprocal approaches, each with centroid and vertex options. Again, numerical simulations are performed on a three-concentric-spheres model for radial and tangential dipoles of varying eccentricities. The inverse solution accuracy of both approaches is compared for the two different skull conductivities and their relative sensitivity to skull conductivity errors and noise is assessed. While the conventional vertex approach yields the most accurate forward solutions for a presumably more realistic skull conductivity value, both conventional and reciprocal approaches exhibit large errors in scalp potentials for highly eccentric dipoles. The reciprocal approaches produce the least variation in forward solution accuracy for different skull conductivity values. In terms of single-dipole inverse solutions, conventional and reciprocal approaches demonstrate comparable accuracy. Localization errors are low even for highly eccentric dipoles that produce large errors in scalp potentials on account of the nonlinear nature of the single-dipole inverse solution. Both approaches are also found to be equally robust to skull conductivity errors in the presence of noise. Finally, a more realistic head model is obtained using magnetic resonance imaging (MRI) from which the scalp, skull, and brain/cerebrospinal fluid (CSF) surfaces are extracted. The two approaches are validated on this type of model using actual somatosensory evoked potentials (SEPs) recorded following median nerve stimulation in healthy subjects. The inverse solution accuracy of the conventional and reciprocal approaches and their variants, when compared to known anatomical landmarks on MRI, is again evaluated for the two different skull conductivities. Their respective advantages and disadvantages including computational requirements are also assessed. Once again, conventional and reciprocal approaches produce similarly small dipole position errors. Indeed, position errors for single-dipole inverse solutions are inherently robust to inaccuracies in forward solutions, but dependent on the overlapping activity of other neural sources. Against expectations, the reciprocal approaches do not improve dipole position accuracy when compared to the conventional approaches. However, significantly smaller time and storage requirements are the principal advantages of the reciprocal approaches. This type of localization is potentially useful in the planning of neurosurgical interventions, for example, in patients with refractory focal epilepsy in whom EEG and MRI are often already performed.
Taillandier, Cédric. "Formulation de la tomographie des temps de première arrivée par une méthode de gradient : un pas vers une tomographie interactive." Phd thesis, 2008. http://tel.archives-ouvertes.fr/tel-00430423/en/.
Повний текст джерелаLin, Huang Tian, and 林晃田. "The analysis of inverse scattering for a dielectric cylinder using integral equation formulations." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/18878959592704945848.
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