Tesis sobre el tema "Modèles de substitutions"
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Chakir, Raja. "Analyse microéconométrique des substitutions inter-énergétiques : application au secteur bois et papier français". Toulouse 1, 2003. http://www.theses.fr/2003TOU10073.
Texto completoThe purpose of this thesis is to analyse interfuel substitution possibilities in the pulp and paper sector in France. The proposed models are useful to evaluate the outcome of price variations or an environmental policy. First, we provide an empirical application of the virtual price approach to the problem of cormer solutions in the case of panel data. The econometric model is an endogenous switching regime model which requires the evaluation of multivariate probability integrals. We estimate the random effect model by maximum likelihood using a panel of French plants from the paper and pulp industry. Next, we propose a Simulated Maximum Likelihood technique for estimation of the simultaneous equation demand system in the case of five forms of energy. Finally, our estimates are used to predict the outcome of an environmental policy aimed at reducing CO2 emissions in the paper and pulp industry. Results show that there are real interfuel substitution possibilities in this sector
Bourdon, Marie-Bénédicte. "Analyse des substitutions entre énergies dans le secteur résidentiel". Dijon, 2003. http://www.theses.fr/2003DIJOE008.
Texto completoHere we first make an attempt for identifying factors which have an impact on demand for energy in home. In a first step, we analyse , over the last decades, the intensity of energy use of various technical possibilities of supplying energy. Focusing the analyse on home appliances and various types of heating equipment we present a retrospect view on the dynamics of household energy demand. I a second step we introduce an econometric modelling process dealing on substitution between various types of energies. Starting with a "translog" model, we find more accurate predictive confidence intervals through a bootstrap process. At this level we must take in account the imperfect condition by which the energy market is ruled ; thus as validation a discrete choice model is tested that reveals a tendency toward complementary rather than substitution effects. Finally a forecast analysis is used to predict house heating units in year 2020
Sinot, François-Régis. "Stratégies Efficaces et Modèles d'Implantation pour les Langages Fonctionnels". Phd thesis, Ecole Polytechnique X, 2006. http://pastel.archives-ouvertes.fr/pastel-00001952.
Texto completoMauguière, Frédéric. "Etude de la dynamique vibrationnelle de molécules triatomiques par les orbites périodiques et leurs bifurcations à partir de modèles effectifs et ab initio : états excités et effets de substitutions isotopiques". Reims, 2009. http://theses.univ-reims.fr/exl-doc/GED00001115.pdf.
Texto completoThis thesis work is devoted to vibrational dynamics of triatomic molecules nucleus. For this problem we have a double approach. First, we make quantum calculations by variational, DVR and contact transformations methods. Then we use nonlinear dynamics methods to interpret quantum results. The first part recalls some mathematics about dynamical systems and bifurcation theory. A review of the problem of vibrations in molecular physics is also given. The second part concerns dynamics of vibration with effective models. These models consist of effective hamiltonians built by contact transformations methods. A correspondence principle is used to obtain classical hamiltonians and then make a periodic orbit analysis. These periodic orbits are systematically compared with quantum wave functions. Finally, the last part discusses the dynamics of vibration directly from the potential energy surface. We lead quantum variational and DVR calculations with large basis. The study of periodic orbits brings to light the quantum results. In a first time we are interested in C2v symmetry group molecules. Then we are interested in isotopic substitions who break the symmetry from C2v to Cs
Baudoui, Vincent. "Optimisation robuste multiobjectifs par modèles de substitution". Phd thesis, Toulouse, ISAE, 2012. http://tel.archives-ouvertes.fr/tel-00742023.
Texto completoDe, lozzo Matthias. "Modèles de substitution spatio-temporels et multifidélité : Application à l'ingénierie thermique". Thesis, Toulouse, INSA, 2013. http://www.theses.fr/2013ISAT0027/document.
Texto completoThis PhD thesis deals with the construction of surrogate models in transient and steady states in the context of thermal simulation, with a few observations and many outputs.First, we design a robust construction of recurrent multilayer perceptron so as to approach a spatio-temporal dynamic. We use an average of neural networks resulting from a cross-validation procedure, whose associated data splitting allows to adjust the parameters of these models thanks to a test set without any information loss. Moreover, the construction of this perceptron can be distributed according to its outputs. This construction is applied to the modelling of the temporal evolution of the temperature at different points of an aeronautical equipment.Then, we proposed a mixture of Gaussian process models in a multifidelity framework where we have a high-fidelity observation model completed by many observation models with lower and no comparable fidelities. A particular attention is paid to the specifications of trends and adjustement coefficients present in these models. Different kriging and co-krigings models are put together according to a partition or a weighted aggregation based on a robustness measure associated to the most reliable design points. This approach is used in order to model the temperature at different points of the equipment in steady state.Finally, we propose a penalized criterion for the problem of heteroscedastic regression. This tool is build in the case of projection estimators and applied with the Haar wavelet. We also give some numerical results for different noise specifications and possible dependencies in the observations
Benard, Emmanuel. "Extension des modèles stochastiques de substitution de nucléotides et son implémentation informatique". Strasbourg, 2011. http://www.theses.fr/2011STRA6212.
Texto completoA first stochastic evolution model of genes was developed by Jukes and Cantor in 1969. One substitution type per nucleotide is taken into account with this model. It was then generalised, in particular with two (Kimura 1980) and three substitution parameters per nucleotide (Kimura 1981). An extension of these models to genetic motifs of size 2 (dinucleotides) and 3 (trinucleotides) was proposed by Frey and Michel in 2006 and Michel in 2007. These extended models allow to study evolution of occurrence probabilities of genetic motifs, both in direct (past-present) and inverse (present-past) evolutionary directions, thanks to analytical solutions computed according to substitution parameters. In this work, we first focused on the extension of these stochastic substitution models for nucleotides, dinucleotides and trinucleotides to genetic motifs of any size, by using a new approach based on Kronecker's operations. A second part was dedicated to the development of a research software SEGM (Stochastic Evolution of Genetic Motifs) allowing the computation of analytical occurrence probabilities of genetic motifs of size 1 to 5 and evolution plots of these motifs. We present an application of these analytical stochastic models to the inverse evolution of splice sites of human genomes introns. In a third part, we developed a numerical stochastic evolution model for trinucleotides with dynamic substitution blockings. We present an application of this model to the inverse evolution of the universal circular code X0 (codon set) discovered in 1996 by Arquès and Michel in eukaryotic and prokaryotic genes
Loreau, Tanguy. "Construction automatique de modèles multi-corps de substitution aux simulations de crashtests". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLC082/document.
Texto completoAt Renault, to fulfill upstream studies, teams in charge of crashworthiness use very simple models to pre-size the vehicle. Today, these models are built from the physical behavior of only one or some reference vehicles. They work and allow to size the project. But today, the company wishes to build its upstream models using all its vehicles. In other words, it wishes to get an automatic method to analyze crashtests simulations to capitalize their results in a database of simplified models.To meet this goal, we decide to use the multi-body model theory. We develop a method to analyze crashtests simulations in order to extract the data required to build a surrogate multi-body model : CrashScan. The analysis process implemented in CrashScan can be split into three major steps.The first one allows to identify the low deformed zones on a crashtest simulation. Then, we can build the topological graph of the future surrogate model. The second step is to analyze the relative kinematics between the low deformed zones : major directions and deformation modes (e.g. crushing or bending) are identified analysing relative movements. The last step is to analyze strengths and moments located between the low deformed zones, viewed in the frames associated to the major directions of deformations in function of the deformations. This allows us to identify equivalent Bouc-Wen hysteretic models. These models have three parameters that we can use : a stiffness, a threshold strength before plastification and a strain of hardening. These parameters can directly be used by upstream studies experts.Finally, we build multi-body models for three different use case. We compare them to their reference over the results they produce for the upstream criteria : models generated with CrashScan seems to grant the precision and the fidelity required to be used during automotive development's upstream phases.To continue this research work and get an industrial solution, there are still some locks to lift, the main ones are : synthesis of any movement into six elementary ones and multi-body synthesis on elements other than beams
Mainguy, Thomas. "Processus de substitution markoviens : un modèle statistique pour la linguistique". Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066354/document.
Texto completoThis thesis proposes a new approach to natural language processing. Rather than trying to estimate directly the probability distribution of a random sentence, we will detect syntactic structures in the language, which can be used to modify and create new sentences from an initial sample.The study of syntactic structures will be done using Markov substitute sets, sets of strings that can be freely substituted in any sentence without affecting the whole distribution. These sets define the notion of Markov substitute processes, modelling conditional independence of certain substrings (given by the sets) with respect to their context. This point of view splits the issue of language analysis into two parts, a model selection stage where Markov substitute sets are selected, and a parameter estimation stage where the actual frequencies for each set are estimated.We show that these substitute processes form exponential families of distributions, when the language structure (the Markov substitute sets) is fixed. On the other hand, when the language structure is unknown, we propose methods to identify Markov substitute sets from a statistical sample, and to estimate the parameters of the distribution. Markov substitute sets show some connections with context-Free grammars, that can be used to help the analysis. We then proceed to build invariant dynamics for Markov substitute processes. They can among other things be used to effectively compute the maximum likelihood estimate. Indeed, Markov substitute models can be seen as the thermodynamical limit of the invariant measure of crossing-Over dynamics
Jung, Matthieu. "Evolution du VIH : méthodes, modèles et algorithmes". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20052/document.
Texto completoNucleotide sequences data enable the inference of phylogenetic trees, or phylogenies, describing their evolutionary re-lationships during evolution. Combining these sequences with their sampling date or country of origin, allows inferring the temporal or spatial localization of their common ancestors. These data and methods are widely used with viral sequences, and particularly with human immunodeficiency virus (HIV), to trace the viral epidemic history over time and throughout the globe. Using sequences sampled at different points in time (or heterochronous) is also a mean to estimate their substitution rate, which characterizes the speed of evolution. The most commonly used methods to achieve these tasks are accurate, but are computationally heavy since they are based on complex models, and can only handle few hundreds of sequences. With an increasing number of sequences avail-able in the databases, often several thousand for a given study, the development of fast and accurate methods becomes essential. Here, we present a new distance-based method, named Ultrametric Least Squares, which is based on the princi-ple of least squares (very popular in phylogenetics) to estimate the substitution rate of a set of heterochronous sequences and the dates of their most recent common ancestors. We demonstrate that the criterion to be optimized is piecewise parabolic, and provide an efficient algorithm to find the global minimum.Using sequences sampled at different locations also helps to trace transmission chains of an epidemic. In this respect, we used all available sequences (~3,500) of HIV-1 subtype C, responsible for nearly 50% of global HIV-1 infections, to estimate its major migratory flows on a worldwide scale and its geographic origin. Innovative tools, based on the principle of parsimony, combined with several statistical criteria were used to synthesize and interpret information in a large phylogeny representing all the studied sequences. Finally, the temporal and geographical origins of the HIV-1 subtype C in Senegal were further explored and more specifically for men who have sex with men
Sinot, François-Regis. "Stratégies efficaces et modèles d'implantation pour les langages fonctionnels". Palaiseau, Ecole polytechnique, 2006. http://www.theses.fr/2006EPXX0021.
Texto completoGilles, Philippe. "Modèle de substitution hybride appliqué à l’interaction de fissures en tridimensionnel". Electronic Thesis or Diss., Ecully, Ecole centrale de Lyon, 2024. http://www.theses.fr/2024ECDL0009.
Texto completoThe interaction of cracks concerns many fields of activity: microelectronics, mechanical industries, aeronautics, nuclear and geophysics. Multiple cracking occurs in composite materials, steels, rocks. In all cases the question arises of the risk of coalescence of these cracks by fatigue, creep or rupture and of their impact on the strength of the structure. Most published studies remain within the framework of linear elasticity. The present study aims to develop a hybrid surrogate model accounting for crack interaction in an infinite isotropic homogeneous medium subjected to a uniform stress field normal to the reference plane. The cracks are through-wall or elliptical, located in the same reference plane, parallel or inclined. The material behavior is linear elastic or élasto-plastic. Since the crack interaction problem is dimensionless, all variables are relative, such as the crack spacing effect which is measured by the ratio of crack spacings to crack sizes. The model consists of a large set of formulas based on theoretical results and computational studies carried out by ESI Group, EDF, Framatome or from the literature. In linear elasticity the interaction factors between two coplanar cracks are affine functions of the normal stress field induced by the first crack considered as isolated. The affine coefficient is a relative difference function A accounting for the differences in crack shape and size and for the action of the second crack on the first one. The normal stress field of a crack located in an infinite isotropic elastic medium is given by exact functions FW like the one derived by H. Westergaard for through-wall cracks. The function A is determined by fitting analytical or numerical results of four to five configurations of the same type such as two unequal elliptical cracks. The function FW takes crack spacing effect into account. The optimal use of this function is ensured by choosing for coplanar through-wall cracks the ratio between the average of the crack sizes and the distance between the centers. This definition is extended to elliptical cracks by relating the average of the length of the normal to the closest points to the distance between intersections with the axes. Parallel cracks may shade each other. The shielding limits are expressed by closed form formulas as a relation between relative horizontal and vertical spacings. For unshielded cracks, the interaction factor is obtained by inverting the coplanar crack interaction factor to get a horizontal shift parameter. This parameter and the relative vertical spacing set as the arguments of the function FW give the interaction factor value. The interaction factor of shielded through-wall cracks is determined by fitting Finite Element results and using asymptotic solutions for unstaggered cracks. For shielded elliptical cracks, only envelope formulas are proposed. Projection rules are proposed for inclined cracks. An equivalent crack coefficient is defined to get a single crack equivalent to two interacting cracks in terms of driving force. This allows to deal with multiple cracks. All the formulas are extended to cracks of unequal size and shape. Therefore, in elasticity, the model covers all the configurations except for twisted elliptical cracks. The concepts of interaction factor, shielding limit and equivalent crack coefficient are extended to an elastic-plastic behavior. For two-dimensional configurations (through-wall cracks) these quantities are derived from finite element results and considerations related to the slip line theory. Another approach, based on a modified version of the reference stress method is developed and generalized to 3D coplanar configurations. The model is extended to the interactions of an embedded crack with the free surface or with a surface crack. A parent method applied to crack – cavity interaction is proposed. The model is validated by comparison to other computational or experimental results
Bompard, Manuel. "MODÈLES DE SUBSTITUTION POUR L'OPTIMISATION GLOBALE DE FORME EN AÉRODYNAMIQUE ET MÉTHODE LOCALE SANS PARAMÉTRISATION". Phd thesis, Université Nice Sophia Antipolis, 2011. http://tel.archives-ouvertes.fr/tel-00771799.
Texto completoZapata, Usandivaras Jose. "Surrogate models based on large eddy simulations and deep learning for coaxial rocket engine injector design". Electronic Thesis or Diss., Toulouse, ISAE, 2024. http://www.theses.fr/2024ESAE0024.
Texto completoThe design of rocket propulsion systems is under growing pressure of reducing development costs. The use of CFD codes for the simulation of rocket engine combustion processes can provide an economical alternative to costly experiments which have traditionally been at the core of liquid rocket engines (LREs) development. Nonetheless, a holistic approach for preliminary design analysis and optimization is not yet practical, as the exploration of the entire engine design space via high-fidelity numerical simulations is intractable. Appropriate surrogate models may circumvent this dilemma through fast restitution times, without significant accuracy loss. The liquid rocket engine injector is a key subsystem within the LRE, whose design directly impacts flame development, combustion efficiency, and thermal loads. The multiscale nature of turbulent, non-premixed combustion, makes the modeling of injection, particularly complex. In this work, we proceed to evaluate data driven strategies for obtaining surrogate models of LRE shear coaxial injectors. A specific emphasis is taken on supervised, deep learning (DL) techniques for regression tasks. The base injector configuration is inspired on an existing experimental rocket combustor from TUM, operating with a GOx/GCH 4 mixture. We begin by conducting a proof-of-concept (PoC), by offline sampling a database of ∼3600 Reynolds Averaged Navier Stokes (RANS), 2D axisymmetric simulations of single element coaxial injectors spanning a 9 dimensional parameter space comprising geometry and combustion regime. Subsequent models of scalar quantities of interest (QoIs),1D wall heat flux profile, and 2D average temperature field are trained and validated. The models use Fully Connected Neural Networks and an adapted U-Net for the 2D case. The results perform well against other established surrogate modeling methods over the test dataset. The RANS approach has evident shortcomings when dealing with turbulent combustion applications. Instead, Large Eddy Simulations (LES), are in principle, better suited to model turbulent combustion, while furnishing information about dynamical flow features. We proceed to replicate the (PoC) efforts, albeit on a database of ∼100 LES of shear coaxial injectors spanning a 3D design space, at a much larger cost per sample than RANS. A dedicated LES data generation pipeline is put in place. Due to the cost, the LES are low-fidelity (LF) in view of the modeling simplifications, i.e. coarse meshes, global chemistry, etc. CNNs and U-Nets are used to obtain surrogate models of scalar QoIs and 2D stationary fields with satisfactory performance over the LF prediction task. To improve the overall fidelity of the surrogate, a multi-fidelity (MF) approach is considered by leveraging inductive transfer learning over our U-Nets. The decoding layers are retrained and validated over a smaller pool of ∼10 of high-fidelity (HF) samples, i.e. finer resolution. The MF surrogate performs well in the HF prediction task over the test samples, with the desired flame topology, at a lower computational cost of the offline sampling stage. The dynamic data of LES, motivates the development of reduced order models (ROMs) for the spatio-temporal prediction of the injector flame. We develop emulators of a LRE injector flame by means of convolutional autoencoders (CNN-AE) and multi-layer perceptron (MLP) for propagating in time the latent vectors. The reconstructed spectral content of the signal outperforms that of a standard POD with equal latent space dimension, demonstrating the superior compression capability of the CNN-AE. However, manifold regularity concerns are raised when propagating the emulator beyond the training horizon. Finally, this work evidences the challenges and opportunities of the use of DL for the prediction of stationary and dynamical features of LES data for a complex reactive flow configuration of a LRE coaxial injector
Cordonnier, Laurie. "Optimisation des traitements de substitution aux opiacés par action conjointe sur les systèmes dopaminergique et opioïde chez la souris". Paris 5, 2006. http://www.theses.fr/2006PA05P615.
Texto completoAmisulpride (D2/D3 dopamine receptor antagonist) and RB101 (mixed inhibitor of enkephalins catabolism) have been associated in this study in order to constitute a novel approach in heroin substitution treatments. After a behavioral study in non-dependent mice, which revealed a potentiation of RB101-induced effects following a chronic treatment with amisulpride, the sustaining neurochemical mechanisms had been investigated thanks to the use of preproenkephalin gene knockout mice and an in situ hybridization technique. The enkephalins role in the control of emotional responses through their action on opioid receptors had then been studied. Finally, the association amisulpride-RB101 had been used to block the expression of morphine-induced behavioral sensitization. These results were compared to classical substitution treatments, buprenorphine and methadone
Rakotoniaina, Jean-Claude. "La transition de phase du dioxyde de vanadium thermochrome : substitution chimique et effets de pression. Elaborations, caractérisations et modélisations". Aix-Marseille 1, 1993. http://www.theses.fr/1993AIX11068.
Texto completoSaclier, Nathanaëlle. "Origine des variations de taux d’évolution moléculaire inter-spécifiques : apport d’un modèle génomique en milieu souterrain". Thesis, Lyon, 2019. https://n2t.net/ark:/47881/m69p310z.
Texto completoThe rate at which DNA accumulates substitutions varies widely among species. Rate variations have been imputed to species intrinsic features (metabolic rate, life history traits) or to the environment characteristics (ionizing radiations, selection pressure). The aim of this PhD project was to investigate the main hypotheses explaining variations in the rate of molecular evolution between species. To achieve that, we combined the unique properties of subterranean isopods from the Asellidae family and high-throughput sequencing data from the nuclear and mitochondrial genome. Asellidae species have made multiple independent transitions to subterranean environments where subterranean species have repeatedly evolved a lower metabolic rate, a longer lifespan and a longer generation time. Moreover, because they are poor dispersers, they are exposed to the same environment across many generations, allowing us to compare species with long-term contrasted features in term of life history traits and environmental characteristics. We found that generation time negatively impact the rate of molecular evolution in the nuclear genome whereas the mitochondrial rate remained unchanged. We also found an increase of the mutation rate for species living in naturally highly radioactive environments. Finally, the study of the rate of molecular evolution variation at a global scale brought forward a systematic bias which needs to be taken into account in studying the link between the mutation rate and diversification
Groussin, Mathieu. "Résurrection du passé à l’aide de modèles hétérogènes d’évolution des séquences protéiques". Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10201/document.
Texto completoThe molecular reconstruction and resurrection of ancestral proteins is the major issue tackled in this thesis manuscript. While fossil molecular data are almost nonexistent, phylogenetic methods allow to estimate what were the most likely ancestral protein sequences along a phylogenetic tree describing the relationships between extant sequences. With these ancestral sequences, several biological hypotheses can be tested, from the evolution of protein function to the inference of ancient environments in which the ancestors were adatapted. These probabilistic estimations of ancestral sequences depend on substitution models giving the different probabilities of substitution between all pairs of amino acids. Classicaly, substitution models assume in a simplistic way that the evolutionary process remains homogeneous (constant) among sites of the multiple sequence alignment or between lineages. During the last decade, several methodological improvements were realised, with the description of substitution models allowing to account for the heterogeneity of the process among sites and in time. During my thesis, I developed new heterogeneous substitution models in Maximum Likelihood that were proved to better fit the data than any other homogeneous or heterogeneous models. I also demonstrated their better performance regarding the accuracy of ancestral sequence reconstruction. With the use of these models to reconstruct or resurrect ancestral proteins, my coworkers and I showed the adapation to temperature is a major determinant of evolutionary rates in Archaea. Furthermore, we also deciphed the nature of the phylogenetic signal informing substitution models to infer a non-parsimonious scenario for the adaptation to temperature during early Life on Earth, with a non-hyperthermophilic last universal common ancestor living at lower temperatures than its two descendants. Finally, we showed that the use of heterogeneous models allow to improve the functionality of resurrected proteins, opening the way to a better understanding of evolutionary mechanisms acting on biological sequences
Ben, Hamza Taoufik. "Le modèle de substitution des exportations logique et facteurs de croissance : le cas de la Tunisie". Paris 10, 1992. http://www.theses.fr/1992PA100093.
Texto completoThis thesis, aims to draw up a summary of the Tunisian policy of industrial export substitution since 1970, and to assess its impact on the economic growth of the country. More specifically it studies the transmission of the growth of the export sector to the internal economy, and develops the direct and indirect effects on the Tunisian economy through the analysis of the mechanisms that are the foundation of this transmission. It also examines the notion of integrate effects. This study consists in empirical analysis in macro-economic terms and in an evaluation through empirical tests of the relationship between exports and economic growth. These tests only establish a relationship but do not explain the mechanisms which it is based on. This explains the recourse to the measure of the integration effects through the use of the instruments of national accounting (T. E. S and T. E. I. ). In order to have a complete view, we have examined the causes of the lack of competitiveness of Tunisian products. We referred to different methods of evaluation of the effective protection
Aupetit, Sébastien. "Contributions aux Modèles de Markov Cachés : métaheuristiques d'apprentissage, nouveaux modèles et visualisation de dissimilarité". Phd thesis, Université François Rabelais - Tours, 2005. http://tel.archives-ouvertes.fr/tel-00168392.
Texto completode métaheuristiques biomimétiques classiques (les algorithmes génétiques, l'algorithme de fourmis artificielles API et l'optimisation par essaim particulaire) au problème de l'apprentissage de MMC. Dans la
deuxième partie, nous proposons un nouveau type de modèle de Markov caché, appelé modèle Markov caché à substitutions de symboles (MMCSS). Un MMCSS permet d'incorporer des connaissances a priori dans le processus d'apprentissage et de reconnaissance. Les premières expérimentations de ces modèles sur des images démontrent leur intérêt. Dans la troisième partie, nous proposons une nouvelle méthode de représentation de dissimilarité appelée matrice de scatterplots pseudo-euclidienne (MSPE), permettant de mieux comprendre les interactions entre des MMC. Cette MSPE est construite à partir
d'une technique que nous nommons analyse en composantes principales à noyau indéfini (ACPNI). Nous terminons par la présentation de la bibliothèque HMMTK, développée au cours de ce travail. Cette dernière intègre des mécanismes de parallélisation et les algorithmes développés au cours de la thèse.
Jung, Matthieu. "Évolution du VIH : méthodes, modèles et algorithmes". Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2012. http://tel.archives-ouvertes.fr/tel-00842785.
Texto completoAurissergues, Elliot. "Essays on macroeconomic theory". Thesis, Paris 1, 2018. http://www.theses.fr/2018PA01E029/document.
Texto completoThis thesis is made of three independent chapters. The first chapter contributes to the literature on expectations. I argue that they may learn a misspecified model instead of learning the rational expectation model. I consider a simple economy with two types of agents. Rational learners learn the true model of the economy whereas consistent learners learn an autoregressive model. I show that a long run equilibrium exists in which consistent learners dominate. Simulations show that the economy may converge towards it. The second chapter deals with the intertemporal choice. I consider a model with wealth in the utility. I study the case of nonseparability. This disentangles between the income effect on labor supply and the intertemporal substitution effect. I derive several implications for economic policy. Then, I estimate the two new parameters introduced in the paper. I find large and positive values for both. The third chapter builds a model of corporate investment under adverse selection. My contribution is to provide a tractable model easy to embed into a macroeconomic model. Borrowers differs by the riskiness of their investment project like in Stiglitz and Weiss (1981). They have infinite horizon and signal their type by borrowing a fraction of their retained earnings. I get an analytic solution for the incentive constraint. I integrate the relation into a dynamic model and derive some implications
Duraffour, Sophie. "Utilisation de différents orthopoxvirus pour le développement de modèles substitutifs du virus de la variole afin d'évaluer l'activité antivirale". Aix-Marseille 2, 2008. http://www.theses.fr/2008AIX20663.
Texto completoThe intentional release of smallpox by bioterrorists is considered to be a significant threat. Although effective smallpox vaccines are available, adverse events to vaccination particularly in immunosupressed individuals can be life threatening. Thus, researches in the field of highly potent antiviral against poxviruses have been intensified. Here we report the use and the development of surrogate models of variola virus, using several related Orthopoxviruses, to study anti-poxviral compounds. We (i) characterized the DNA repair protein uracil-DNA glycosylase of monkeypox virus, which is essential for orthopoxvirus replication and thus its inhibition is a rational therapeutic strategy, (ii) developed in vitro, ex vivo and in vivo surrogate model of variola virus by using its closest known related virus, camelpox virus; and (iii) investigated the mode of action of a novel anti-orthopoxvirus molecule, ST-246, against three Orthopoxviruses, vaccinia, cowpox and camelpox viruses
Bois, Joackim. "Synthèse de ligands calixarèniques et thiacalixarèniques chiraux : contribution à l’étude de la reconnaissance énantiosélective d’acides aminés modèles". Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10228.
Texto completoMolecular recognition is a fundamental and universal process in biological systems. This work aims to contribute to the understanding of phenomena involved in this recognition by the use of artificial receptors able to complex and discriminate amino acids. Because of their rigidity and their functional modularity, calix[4]arenes and thiacalix[4]arenes are good starting materials for the design of these receptors. A series of 12 chiral homo and heteroditopic calix[4]arenes and thiacalix[4]arenes bearing amino acids derivatives has been synthesized. In order to improve the synthesis of heteroditopic receptors, an original and selective method for the preparation of mono-O-functionalized calix[4]arenes was developed. This procedure, based on the de-O-functionalization of 1,3 di-O-substituted calix[4]arenes by titanium tetrachloride (TiCl4), yielded a series of calix[4]arenes, mono-O-substituted by various functional groups (alcohol, halogen, nitrile, ester, alkyne ...). A mechanistic study revealed the formation of two titanium calixarene complexes during the reaction. After characterization of all these compounds, complexation studies of chiral receptors with neutral N-tosyl amino acids derivatives (valine, leucine, and phenylalanine) were done. Various investigations carried out by mass spectrometry, microcalorimetry and 1 H NMR allowed us to establish the ability of some ligands to complex and discriminate amino acids. Stoichiometry and association constants of the complexes were determined. 2D NMR (NOESY, COSY) studies were used to specify the bonds implied in complex formation
Miranda, Karen. "Algorithmes d'auto-déploiement adaptatifs pour des réseaux de substitution mobiles sans fil". Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2013. http://tel.archives-ouvertes.fr/tel-00918017.
Texto completoMiranda, Campos Karen Samara. "Algorithmes d'auto-déploiement adaptatifs pour des réseaux de substitution mobiles sans fil". Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10147/document.
Texto completoIn case of a disaster, the communication infrastructure may be partially or totally destroyed, or insufficient due to the high data traffic. Despite this, it is necessary to provide connectivity between the rescue teams and the command center. Therefore, temporary communication solutions are crucial until the infrastructure is restored. In this thesis, we focus on the deployment of communication solution called substitution networks. Thus, we propose a self-deployment algorithm to allow mobile routers that compose a substitution network spread out to cover the target area. Our algorithm monitors the network conditions to decide whether the router should move or not, adjusting its position based on one-hop information by means of active measurement, i.e., probe packets. Such probe packets allows the algorithm to monitor the channel and its eventual changes over time. If the probe transmission rate is enough high, the insights obtained will be accurate, however, the overhead will increase proportionally consuming network resources. Hence, we propose to use surrogate data obtained by means of an autoregressive estimator to reduce the overhead without impacting our deployment algorithm. We show by simulation the efficiency of both algorithms and their performance in terms of deployment time, delay, jitter, and throughput
Wang, Yan. "Elaboration de modèles collagène/apatite pour l'étude de la biominéralisation du tissu osseux". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00839469.
Texto completoGimadiev, Timur. "Modèles prédictifs pour les paramètres cinétiques et thermodynamiques des réactions chimiques". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF007/document.
Texto completoThis work is devoted to QSPR modeling of kinetic and thermodynamic properties of chemical reactions using the Condensed Graph of Reaction (CGR) approach. CGR allows encoding structures of reactants and products into one sole molecular graph for which molecular descriptors can be generated. A comprehensive database containing some 11000 manually collected reactions has been developed then used in the modeling. Predictive models were built for rate constants of Diels-Alder, SN2 and E2 reaction as well as for equilibrium constants of tautomeric transformations. They are available for the users via WEB portal. A part of the thesis concerned quantum mechanics studies of reactions between sydnones and strained alkynes for which the size of the dataset was not sufficient to produce statistically meaningful models
Langle, Frédéric. "Contribution à l'élaboration de design de substitution en similitude indirecte sur modèles réduits : application à l'étude du comportement en collision des absorbeurs axiaux". Valenciennes, 1997. https://ged.uphf.fr/nuxeo/site/esupversions/ada00313-2944-431c-9aa0-8bbd91c168be.
Texto completoBettinotti, Omar. "A weakly-intrusive multi-scale substitution method in explicit dynamics". Thesis, Cachan, Ecole normale supérieure, 2014. http://www.theses.fr/2014DENS0032/document.
Texto completoComposite laminates are increasingly employed in aeronautics, but can be prone to extensive delamination when submitted to impact loads. The need of performing virtual testing to predict delamination becomes essential for engineering workflows, in which the use of a fine modeling scheme appears nowadays to be the preferred one. The associated computational cost would be prohibitively high for large structures. The goal of this work consists in reducing such computational cost coupling the fine model, restricted to the surroundings of the delamination process zone, with a coarse one applied to the rest of the structure. Due to the transient behavior of impact problems, the dynamic adaptivity of the models to follow evolutive phenomena represents a crucial feature for the coupling. Many methodologies are currently used to couple multiple models, such as non-overlapping Domain Decomposition method, that, applied to dynamic adaptivity, has to be combined with a re-meshing strategy, considered as intrusive implementation within a Finite Element Analysis software. In this work, the bases of a weakly-intrusive approach, called Substitution method, are presented in the field of explicit dynamics. The method is based on a global-local formulation and is designed so that it is possible to make use of the pre-fixed coarse model the meshes the whole structure to obtain a global response: this pre-computation is then iteratively corrected considering the application of the refined model only where required, in the picture of an adaptive strategy. The verification of the Substitution method in comparison with the Domain Decomposition method is presented
Guelilia, Zakaria. "Modélisation électromagnétique rapide de problèmes multi-échelles incluant une partie variable - Application à la dosimétrie numérique et au couplage entre antennes". Thesis, Rennes, INSA, 2014. http://www.theses.fr/2014ISAR0006/document.
Texto completoNumerical modelling is an essential tool for solving electromagnetic problems. The computation time and the accuracy of the results depend on the description level used and electrical dimensions of the analyzed problem. When it is necessary to model an electrically large environment, the use of conventional methods such as the finite difference time domain (FDTD) face difficulties in terms of simulation time. This becomes particularly problematic when the analysis must be carried out for several values of one or more parameters defining the studied problem. Considering this variability aspect and in order to avoid multiplication of costly simulations, it is necessary to choose suitable methods. This thesis aims to develop a new approach to solve effectively the variable feature encountered in some multi-scale problems. This new method called the MM-DG-FDTD (MacroModel based Dual Grid-FDTD) results from the association of the Dual Grid- FDTD (DG-FDTD) method with a substitution model. The use of the DG-FDTD permits to treat multiscale aspect dividing the studied problem into FDTD sub-volumes. Each step has its own simulation parameters. The fast substitution model built in few electromagnetic simulations replaces in a rigorous and efficient way the last expensive DG-FDTD simulation. The proper operation of the substitution model is firstly validated using simple cases. Next, a use of the MM-DG-FDTD is performed on two applications belonging to two contexts: numerical dosimetry and antennas coupling. The first one proposes to estimate the value of the electric field inside the left eye of a human body model. It receives electromagnetic radiation from an antenna located onboard a vehicle. This study is carried out for a large number of positions of the body around the vehicle. The second application is to assess the value of the transmission coefficient between two UWB (Utra-Wide Band) antennas. The position of the receiving antenna changes in a large environment. For both studies, MM-DG-FDTD shows its ability to give fast and accurate results compared to a classic use of the DG-FDTD
Allam, Diana. "Loose coupling and substitution principle in objet-oriented frameworks for web services". Thesis, Nantes, Ecole des Mines, 2014. http://www.theses.fr/2014EMNA0115/document.
Texto completoToday, the implementation of services (SOAP and RESTful models) and of client applications is increasingly based on object-oriented programming languages. Thus, object-oriented frameworks for Web services are essentially composed with two levels: an object level built over a service level. In this context, two properties could be particularly required in the specification of these frameworks: (i)First a loose coupling between the two levels, which allows the complex technical details of the service level to be hidden at the object level and the service level to be evolved with a minimal impact on the object level, (ii) Second, an interoperability induced by the substitution principle associated to subtyping in the object level, which allows to freely convert a value of a subtype into a supertype. In this thesis, first we present the existing weaknesses of object-oriented frameworks related to these two requirements. Then, we propose a new specification for object-oriented Web service frameworks in order to resolve these problems. As an application, we provide an implementation of our specification in the cxf framework, for both SOAP and RESTful models
Gelly, Jean-Christophe. "Système d'information et outils de prédiction structurale spécifiques de classes de protéines : Base de données KNOTTIN et matrices de substitution EvDTree dépendantes de la structure". Montpellier 2, 2004. http://www.theses.fr/2004MON20026.
Texto completoOlivier, Clément. "Décompositions tensorielles et factorisations de calculs intensifs appliquées à l'identification de modèles de comportement non linéaire". Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM040/document.
Texto completoThis thesis presents a novel non-intrusive methodology to construct surrogate models of parametric physical models.The proposed methodology enables to approximate in real-time, over the entire parameter space, multiple heterogeneous quantities of interest derived from physical models.The surrogate models are based on tensor train representations built during an intensive offline computational stage.The fundamental idea of the learning stage is to construct simultaneously all tensor approximations based on a reduced number of solutions of the physical model obtained on the fly.The parsimonious exploration of the parameter space coupled with the compact tensor train representation allows to alleviate the curse of dimensionality.The approach accommodates particularly well to models involving many parameters defined over large domains.The numerical results on nonlinear elasto-viscoplastic laws show that compact surrogate models in terms of memory storage that accurately predict multiple time dependent mechanical variables can be obtained at a low computational cost.The real-time response provided by the surrogate model for any parameter value allows the implementation of decision-making tools that are particularly interesting for experts in the context of parametric studies and aim at improving the procedure of calibration of material laws
Boutoux, Guillaume. "Sections efficaces neutroniques via la méthode de substitution". Phd thesis, Bordeaux 1, 2011. http://tel.archives-ouvertes.fr/tel-00654677.
Texto completoSofeu, Casimir. "Développement de méthodes pour la validation de critères de substitution en survie : méta-analyses de cancer". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0383.
Texto completoSurrogate endpoint can be used instead of the most relevant clinical endpointto assess the efficiency of a new treatment. In a meta-analysis framework, the classical approach for the validation of surrogate endpoint is based on a two-step analysis. For failure time endpoints, this approach often raises estimation issues.We propose a one-step validation approach based on a joint frailty and a joint frailty-copula model.The models include both trial-level and individual-level random effects or copula functions. We chose a non-parametric form of the baseline hazard functions using splines. We estimated parameters and hazard functions using a semi-parametric penalized marginal likelihood method, considering various numerical integration methods. Both individual level and trial level surrogacy were evaluated using Kendall's tau and coefficient of determination. The performance of the estimators was evaluated using simulation studies. The models were applied to individual patient data meta-analyses in cancer clinical trials for assesing potentiel surrogate endpoint to overall survival.The models were quite robust with a reduction of convergence and model estimation issues encountered in the two-step approach.We developed a user friendly R package implementing the models
Senouci, Mehdi. "Essays on Economic Growth". Paris, EHESS, 2014. http://www.theses.fr/2014EHES0090.
Texto completoThis thesis consists of five (mostly theoretical) chapters on economic growth. We address both medium- and long-run issues. All the models presented are of neoclassical structure and are animated by some forms of technical change related to physical capital. The first four chapters analyze the behavior of neoclassical growth models under investment-specific technical change — i. E. Under technical change in the production of the investment good. The fifth chapter introduces another representation of technical change in neoclassical growth models. Chapter 1 analyses the consequences of investment-specific technological shocks on the golden rule steady state. Chapter 2 addresses the Malthusian issue of the demographic consequences of technical change in an overlapping-generations model of growth with land, endogenous fertility and multiple directions of productivity growth. Chapter 3 (co-written with Gwenael Moysan) presents new results on neoclassical two-inputs production functions, and uses them to treat the Solow model with capital-augmenting (or investment-specific) technological change. Chapter 4 investigates the endogenous direction of technical change-— labor-augmenting vs. Investment-specific— in the discrete-time Ramsey framework with log utility. Chapter 5 shows how the Habakkuk hypothesis and the Kaldor facts can be rationalized through a new form of technological change
Kpoton, Agapit. "De la stéréochimie de la substitution nucléophile sur le silicium à la synthèse de silanes pentacoordonnés modèles : mise en évidence de la pseudorotation au niveau de l'atome de silicium". Montpellier 2, 1991. http://www.theses.fr/1991MON20120.
Texto completoRadulescu, Bruno. "Développement d'un système de contrôle et de gestion des processus de conception intégrée : application à la traduction et à la substitution au sein d'un modèle produit". Grenoble INPG, 2005. http://www.theses.fr/2005INPG0060.
Texto completoTo be at the head of the competition on the globalized market, companies develop innovative products, with a very good quality and a lower cost, in increasingly shorter times. Ln this context, the phase of development of the product has an enormous importance for the economic success of manufacturers. The main question of this work is to describe how the different trades and disciplines are implicated in an colaborative environement can work together in order to exploit the potentioal of the integrated design approach. Ln the previously developed CoDeMo (Cooperative Design Modeller) system, we explored the tasks of the "internal actor", in assisting the design team through the management of certain tasks : translation, diffusion of information, verification on constraints and communication management. The second question treated in this work relates to the integration and the use of a specific work tool in the environment of designer. We present a model, which has the goal to propose a formai design process for a product model in its design characteristics for the integrated design. The product model acts as a help to the designer who takes part in a concurrent design. Rules were included in the product model to check the coherence between the various levels of description
Belkaï, Emilie. "Etude comparative des effets des traitements de substitution à l'héroïne : méthadone et buprénorphine haut dosage sur les régulations transcriptomiques induites par la morphine chez le rat". Paris 5, 2010. http://www.theses.fr/2010PA05P622.
Texto completoCurrently two heroin maintenance treatments are used in France: methadone and buprenorphine. However, the understanding of the biological mechanisms induced by these treatments is still, limiting the available therapeutic strategies. Using real time quantitative PCR, we studied in rats, the genomic impact of these maintenance treatment in the brain as compared to the reference opioid, morphine. Analysis of genomic and behavioral responses to acute injection of equipotent doses showed that buprenorphine induces a distinctive pharmacological and genomic profile. A second study using TaqMan ® Array technology gave us insights into the molecular impact of buprenorphine in the brain. Furthermore, a comparison study between buprenorphine and morphine on blood mononuclear cells has opened pathways to the identification of biomarkers in the periphery. These studies open the way to understanding the molecular impact of buprenorphine in the brain but also in peripheral tissue samples for non-invasive analyses, thus facilitating a transfer to clinical research to better understand the molecular effects long term of buprenorphine administered to patients
Doan, Van Tu. "Modèles réduits pour des analyses paramètriques du flambement de structures : application à la fabrication additive". Thesis, Valenciennes, 2018. http://www.theses.fr/2018VALE0017/document.
Texto completoThe development of additive manufacturing allows structures with highly complex shapes to be produced. Complex lattice shapes are particularly interesting in the context of lightweight structures. However, although the use of this technology is growing in numerous engineering domains, this one is not enough matured and the correlations between the experimental data and deterministic simulations are not obvious. To take into account observed variations of behavior, multiparametric approaches are nowadays efficient solutions to tend to robust and reliable designs. The aim of this thesis is to integrate material and geometric uncertainty, experimentally quantified, in buckling analyses. To achieve this objective, different surrogate models, based on regression and correlation techniques as well as different reduced order models have been first evaluated to reduce the prohibitive computational time. The selected projections rely on modes calculated either from Proper Orthogonal Decomposition, from homotopy developments or from Taylor series expansion. Second, the proposed mathematical model is integrated in fuzzy and probabilistic analyses to estimate the evolution of the critical buckling load for lattice structures
Skarvelakis, Constantin. "Préparation d'un combustible de substitution à base de charbon pré-épuré : l'ultracarbofluide : mise en œuvre d'un pilote de production et contrôle de la formulation par un rhéomètre en ligne". Compiègne, 1992. http://www.theses.fr/1992COMPD533.
Texto completoCampos, Manuel. "Analyse structurale et fonctionnelle du pseudopilus assemblé par le système de sécrétion de type II de Klebsiella oxytoca". Paris 7, 2010. http://www.theses.fr/2010PA077139.
Texto completoMany Gram-negative bacteria secrete specific proteins to the extracellular milieu via the type II secretion Systems (T2SS). Under specific conditions, T2SS assemble pili on the bacterial surface, composed of pseudopilins. These dynamic filaments, called the pseudopili, are localized in the periplasm and play an essential role in protein secretion. They could act as a piston to push the protein substrate through the channel in the outer membrane, or drive conformational changes of secretion System components involved in the channel gating. The objective of this work was to determine the structure and understand the assembly of the pseudopilus from the pullulanase-specific T2SS of Klebsiella oxytoca. PulG is the main subunit of the pseudopilus. Pseudo-atomic resolution models were generated by a new flexible docking procedure, using ambiguous distance restraints. Predicted electrostatic interactions were validated by introducing single deleterious and double compensatory charge inversions. Extensive mutational analysis of the major pseudopilin PulG led to the isolation of variants allowing for uncoupling secretion and piliation, or affected in early steps of their biogenesis. In addition, inter-residue distances in the pilus core were probed using double cysteine substitutions in the PulG TMS, followed by cross-linking. This approach allowed us not only to validate the models, but also provided a biochemical tool to probe the assembly of the so-far elusive periplasmic pseudopilus. Using covalent cross-linking we could test the role of different T2SS components in thé pseudopilus biogenesis
Sanchez, Florian. "Génération de modèles analytiques pour la conception préliminaire de systèmes multi-physiques : application à la thermique des actionneurs et des systèmes électriques embarqués". Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30081/document.
Texto completoThe objective of this thesis is to develop methods and tools dedicated to the preliminary design of multi-physical systems, with a particular attention to the thermal modelling of actuators and embedded electrical systems. This need arises from the current industrial research which led to the More Electrical Aircraft program (MEA), which deals with new technologies of embedded systems where the thermal management of such devices is essential. First of all, this thesis proposes a methodology based on dimensional analysis and surrogate modelling technique to generate analytical models from finite element simulations. Furthermore, a methodology for constructing optimal design of experiments intended for building surrogate models using dimensionless variables is also proposed. Finaly, two numerical approaches which enable to reduce the number of dimensionless variables of a problem and to study their physical significance are proposed. The first approach uses sensitivity analysis in an original way to highlight the physical significance of the dimensionless numbers for a considered problem. The second approach uses optimization algorithms to reduce the number of dimensionless variables. In the second part of the thesis, the proposed methods were successfully applied to model several components of an electromechanical actuator (EMA) of an aileron (electrical brushless motor, mechanical housing, etc.), and of a power converter (capacitor, inductance, heatsink) used in an aeronautical context
Dos, Santos Lourenço João. "Les causes des variations du taux d’évolution moléculaire entre lignées". Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20084/document.
Texto completoThe main objective of the present thesis is to elucidate the causes of variations in rates of molecular evolution among lineages, and in particular, to understand how factors connected to mutation, selection and genetic drift can influence these variations
Chabanet, Sylvain. "Contributions aux ombres et jumeaux numériques dans l’industrie : proposition d’une stratégie de couplage entre modèles de simulation et d’apprentissage automatique appliquée aux scieries". Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0131.
Texto completoThis thesis is part of the ANR project Lorraine-Artificial Intelligence, a multi-disciplinary project promoting research into both artificial intelligence itself, and its applications to other fields. As such, this thesis focuses on the development and use of machine learning models as a substitute for simulation models. Interest in this research topic is fueled by academic and industrial interest in the concept of digital shadows and twins, seen as an evolution of simulation models for long-term use at the heart of systems and processes. The main contribution of this thesis is the proposal of a coupling strategy between a simulation model and a surrogate model performing the same prediction task repeatedly on a data stream. The simulation model is assumed to have a high level of fidelity, but to be too slow or computationally expensive to be used alone to perform the full range of prediction required. The surrogate model is a fast machine-learning model that approximates the simulation model. The primary objective of the proposed coupling strategy is the efficient use of limited computational resources by intelligently allocating each prediction request to one of the two models. This allocation is, in particular, inspired by active learning and based on the evaluation of the level of confidence in the predictions of the machine learning model. Numerical experiments are first carried out on eight datasets from the scientific literature. An application to the sawmilling industry is then developed
Dupuis, Romain. "Surrogate models coupled with machine learning to approximate complex physical phenomena involving aerodynamic and aerothermal simulations". Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0017/document.
Texto completoNumerical simulations provide a key element in aircraft design process, complementing physical tests and flight tests. They could take advantage of innovative methods, such as artificial intelligence technologies spreading in aviation. Simulating the full flight mission for various disciplines pose important problems due to significant computational cost coupled to varying operating conditions. Moreover, complex physical phenomena can occur. For instance, the aerodynamic field on the wing takes different shapes and can encounter shocks, while aerothermal simulations around nacelle and pylon are sensitive to the interaction between engine flows and external flows. Surrogate models can be used to substitute expensive high-fidelitysimulations by mathematical and statistical approximations in order to reduce overall computation cost and to provide a data-driven approach. In this thesis, we propose two developments: (i) machine learning-based surrogate models capable of approximating aerodynamic experiments and (ii) integrating more classical surrogate models into industrial aerothermal process. The first approach mitigates aerodynamic issues by separating solutions with very different shapes into several subsets using machine learning algorithms. Moreover, a resampling technique takes advantage of the subdomain decomposition by adding extra information in relevant regions. The second development focuses on pylon sizing by building surrogate models substitutingaerothermal simulations. The two approaches are applied to aircraft configurations in order to bridge the gap between academic methods and real-world applications. Significant improvements are highlighted in terms of accuracy and cost gains
Hadj, Ali Kamal. "Étude cinétique de l'oxydation et de l'auto-inflammation en milieux gazeux homogène pauvre et ultra pauvre de carburants de substitution issus de la biomasse". Lille 1, 2007. http://www.theses.fr/2007LIL10004.
Texto completoKreuawan, Sangkla. "Modélisation et conception optimale pour les applications ferroviaires". Phd thesis, Ecole Centrale de Lille, 2008. http://tel.archives-ouvertes.fr/tel-00363633.
Texto completoLa conception systémique optimale de composant électrotechnique est abordée dans cette thèse. Une chaîne de traction électrique est choisie comme exemple représentatif d'un système complexe. La démarche et les outils sont mis en œuvre sur deux applications: la conception d'un moteur de traction et la conception simultanée de plusieurs composants clés.
Pour concevoir un moteur de traction, le cycle de fonctionnement et le comportement thermique transitoire sont primordiaux. La bonne adaptation du moteur à sa mission permet de réduire considérablement sa masse. L'approche multidisciplinaire est utilisée pour gérer les interactions entre modèles de disciplines différentes au sein d'un même processus d'optimisation. Suivant la méthode employée, le temps d'optimisation peut être réduit grâce à la répartition des taches par domaine physique et d'en paralléliser l'exécution. Des optimisations multiobjectif ont également été appliquées. Des fronts de Pareto sont obtenus malgré l'utilisation d'un modèle précis mais coûteux, le modèle éléments finis.
L'approche décomposition hiérarchique de la méthode "Target Cascading" est appliquée au problème de conception de la chaîne de traction. Le système et ses composants sont conjointement conçus. Cette méthode est bien adaptée à la démarche de conception optimale des systèmes complexes, tout en respectant l'organisation par produit de l'entreprise.
Chamaret, Damien. "Plate-forme de réalité virtuelle pour l'étude de l'accessibilité et de l'extraction de lampes sur prototype virtuel automobile". Phd thesis, Université d'Angers, 2010. http://tel.archives-ouvertes.fr/tel-00540899.
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