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Статті в журналах з теми "Schémas préservant la structure":
Gallice, Gérard. "Schémas de type Godunov entropiques et positifs préservant les discontinuités de contact." Comptes Rendus de l'Académie des Sciences - Series I - Mathematics 331, no. 2 (July 2000): 149–52. http://dx.doi.org/10.1016/s0764-4442(00)01601-3.
Viana dos Santos, Gabriela, Laurence Buson, and et Jean-Pierre Chevrot. "Acquisition et structure des schémas sociolinguistiques en langue étrangère." SHS Web of Conferences 46 (2018): 10007. http://dx.doi.org/10.1051/shsconf/20184610007.
Mas, Sabine. "Caractéristiques de schémas de classification personnels des documents administratifs électroniques : éléments d’analyse et de discussion." Documentation et bibliothèques 55, no. 1 (March 11, 2015): 5–17. http://dx.doi.org/10.7202/1029047ar.
Gélinas, Jocelyne. "Cohabitation de la structure organisationnelle fonctionnelle avec la structure dite de « projet » : identification des meilleures pratiques de gestion." Revue Organisations & territoires 26, no. 1-2 (September 1, 2017): 131–44. http://dx.doi.org/10.1522/revueot.v26i1-2.203.
Levanova, Albina. "Teaching English idioms to Russian learners of English : Cognitive approach." Recherches anglaises et nord-américaines 36, no. 2 (2003): 49–55. http://dx.doi.org/10.3406/ranam.2003.1687.
ELSEN, J. M. "La gestion des populations : De l’optimisation au progrès génétique réalisé dans les schémas de sélection." INRAE Productions Animales 5, HS (December 2, 1992): 237–42. http://dx.doi.org/10.20870/productions-animales.1992.5.hs.4297.
Tessier, Stéphane. "Familles d’ailleurs, école d’ici – Un face-à-face d’histoires et de désirs." Diversité 163, no. 1 (2010): 174–80. http://dx.doi.org/10.3406/diver.2010.3363.
GANKA, Gabin, Kolawolé Valère SALAKO, and Adandé Belarmain FANDOHAN. "Impacts des tabous et des cérémonies rituelles sur la structure des peuplements de Triplochiton scleroxylon K. Schum., un arbre sacré au Bénin." BOIS & FORETS DES TROPIQUES 357 (October 1, 2023): 57–70. http://dx.doi.org/10.19182/bft2023.357.a36900.
Sériot, Patrick. "L'ours ou le chasseur : qui a tué qui? (le couple sujet-objet dans la typologie syntaxique stadiale, URSS 1930-1940)." Cahiers du Centre de Linguistique et des Sciences du Langage, no. 25 (April 9, 2022): 263–94. http://dx.doi.org/10.26034/la.cdclsl.2008.1401.
McNeil, J. Kevin, M. J. Stones, Albert Kozma, and David Andres. "Age Differences in Mood: Structure, Mean Level, and Diurnal Variation." Canadian Journal on Aging / La Revue canadienne du vieillissement 13, no. 2 (1994): 201–20. http://dx.doi.org/10.1017/s0714980800006024.
Дисертації з теми "Schémas préservant la structure":
Alama, Bronsard Yvonne. "Schémas numériques pour les équations dispersives non linéaires : analyse à faible régularité, cadre aléatoire et préservation de symétries." Electronic Thesis or Diss., Sorbonne université, 2024. http://www.theses.fr/2024SORUS065.
The work presented in this thesis belongs to the field of numerical analysis, and builds on tools stemming from the study of partial differential equations (PDEs). We focus on time discretizations to nonlinear dispersive equations. The aim is to reduce the smoothness assumptions on the design and analysis of numerical methods, in order to treat low-regularity dynamics.Part I of the thesis develops novel low-regularity schemes, suited for general bounded domains. Chapter 2 presents first and second order convergence results for the Gross-Pitaevskii equation, when both the initial data and the potential are non-smooth. Chapter 3 generalizes the construction of these schemes to higher order and to a general class of nonlinear evolution equations with potentials.Part II of the thesis consists of Chapter 4, which considers higher-order constructions for randomized initial conditions. Part III of the thesis considers the long-time properties and invariants of the equation, and deals with structure-preserving schemes. We first introduce in Chapter 5 a novel symmetric time integrator for the nonlinear Schr ̈odinger equation. We give fractional convergence rates as a function of the Sobolev regularity of the initial data. Chapter 6 extends the latter work by constructing higher order symmetric integrators for a general class of dispersive equations. All these new symmetric schemes exhibit excellent structure preservation and convergence properties, which are witnessed in numerical experiments.The higher order extensions of Chapters 3, 4, 6 follow new techniques based on decorated tree series, inspired by singular stochastic PDEs via the theory of Regularity Structures
Falissard, Fabrice. "Schémas numériques préservant la vorticité en aérodynamique compressible." Phd thesis, Paris, ENSAM, 2006. http://pastel.archives-ouvertes.fr/pastel-00002056.
Blachère, Florian. "Schémas numériques d'ordre élevé et préservant l'asymptotique pour l'hydrodynamique radiative." Thesis, Nantes, 2016. http://www.theses.fr/2016NANT4020/document.
The aim of this work is to design a high-order and explicit finite volume scheme for specific systems of conservation laws with source terms. Those systems may degenerate into diffusion equations under some compatibility conditions. The degeneracy is observed with large source term and/or with late-time. For instance, this behaviour can be seen with the isentropic Euler model with friction or with the M1 model for radiative transfer, or with the radiation hydrodynamics model. We propose a general theory to design a first-order asymptotic preserving scheme (in the sense of Jin) to follow this degeneracy. The scheme is proved to be stable and consistent under a classical hyperbolic CFL condition in both hyperbolic and diffusive regimes, for any 2D unstructured mesh. Moreover, we justify that the developed scheme also preserves the set of admissible states in all regimes, which is mandatory to conserve physical solutions. This construction is achieved by using the non-linear scheme of Droniou and Le Potier as a target scheme for the diffusive equation, which gives the form of the global scheme for the complete system of conservation laws. Then, the high-order scheme is constructed with polynomial reconstructions and the MOOD paradigm as a limiter. The main difficulties are the preservation of the set of admissible states in both regimes on unstructured meshes and to deal with the high-order polynomial reconstruction in the diffusive limit without losing the asymptotic preserving property. Numerical results are provided to validate the scheme in all regimes, with the first and high-order versions
Duarte, Denio. "Une méthode pour l'évolution de schémas XML préservant la validité des documents." Phd thesis, Tours, 2005. http://tel.archives-ouvertes.fr/tel-00009693.
L'utilisateur donne au système ce qu'il souhaite comme nouveau document devant être accepté par le schéma.
À partir de ce document, le système construit des schémas candidats, qui d'une part préservent la validité de la base de documents et, d'autre part augmentent la classe de documents acceptée par le schéma.
L'approche est implantée par un algorithme appelé GREC.
Cet algorithme utilise l'automate d'arbre A qui accepte le langage défini par le schéma pour trouver les informations nécessaires à la modification.
Plus précisément, il utilise les expressions régulières des règles de transitions de A pour proposer les candidats.
Ainsi, les modifications sont faites sur les graphes qui représentent les automates d'états finis construits à partir des expressions régulières concernées.
Les expressions régulières engendrées par GREC représentent des schémas présentés à l'utilisateur afin qu'il choisisse le plus adapté à la sémantique de son application.
Hoarau, Emma. "Mise en évidence de la brisure de symétrie des schémas numériques pour l'aérodynamique et développement de schémas préservant ces symétries." Paris 6, 2009. http://www.theses.fr/2009PA066650.
Bulteau, Solène. "Développement et analyse de schémas numériques préservant les régimes asymptotiques de diffusion linéaire et non linéaire." Thesis, Nantes, 2019. http://www.theses.fr/2019NANT4046.
The aim of this work is to build and analyse schemes able to discretize the solutions of hyperbolic systems of conservation laws endowed with a source term. The main property required here is the preservation of the asymptotic behaviour, in other words the schemes must stay accurate in the diffusive regime, namely the long time and stiff source term regime. This manuscript is divided in two parts. The first one is dedicated to the presentation of a rigourous numerical convergence result for a scheme discretizing the solutions of the p-system. The convergence rate obtained is explicitly exhibited and coincides with the results obtained in the continuous and semi-discrete frameworks. The second part is devoted to the development of asymptotic preserving schemes and two methods are proposed. The first one is a generalization of the perturbed HLL method introduced by Berthon and Turpault in order to treat source terms of quadratic form and the second one is able to preserve both all the steady states and the diffusive limit
Bennoune, Mounir. "Approximation numérique de quelques équations cinétiques préservant leurs asymptotiques fluides." Toulouse 3, 2009. http://thesesups.ups-tlse.fr/845/.
This thesis is a contribution in the development of asymptotic preserving numerical schemes for kinetic equations. This work contains two parts. The first one is concerned with the development of numerical schemes for like Boltzmann kinetic equations, which are able to preserve the Euler limit as well as the compressible Navier-Stokes asymptotics (which is not a limit) near the hydrodynamical regime. Our strategy consists in rewriting the kinetic equation as a coupled system of kinetic part and macroscopic one, by using the micro-macro decomposition of the distribution function as a sum of its corresponding (Maxwellian) equilibrium distribution plus the deviation. The simulations are performed for the one-dimensional BGK model, and then extended for this model in higher velocity dimension. The second part is concerned with the construction of asymptotic preserving scheme in the diffusion limit for the Kac's equation. This model is much simpler that the Boltzmann equation (it is one dimensional), but it has the same quadratic structure, while the models used in the previous part were only relaxation operators. However, contrary to the Boltzmann equation, the natural fluid limit of the Kac model is a non linear diffusion equation. We also construct in this part a deterministic velocity discretization for the collisional operator. Such discretization is based on a simple new formulation of the Kac operator. Several simulations are presented in order to illustrate the efficiency of our approach
Delhem, Romain. "Verbes labiles et schémas de complémentation en anglais." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUL068.
Within a constructionist framework, this thesis studies English labile verbs, which can enter into various syntactic configurations without changing form. A study of their complementation shows that categorizing them into semantic families is relevant but not sufficient to explain their behavior. The thesis defends a syncretic approach to verb complementation to that accounts for its important productivity and its sometimes arbitrary limits. It is shown that all verbs have a default syntactic configuration, which is not meaningful and which simply allows the verb to express its arguments in an unmarked way, in accordance with certain principles of conceptual coherence. Conversely, when the complementation of the verb has an identifiable semantic contribution, the existence of fully meaningful patterns of complementation is posited. These are defined as sets of complements, whose meaning is distinct from that of the verb with which they are associated and is found regularly with verbs of diverse categories. It is shown that patterns of complementation should be considered fully-fledged English linguistic units. This implies that synchronically, these patterns are mentally stored by speakers rather than the result of a process of analogy with existing constructions. Their status as linguistic units makes it possible to study their meaning in the same way as more classical lexical units. Although most of them are polysemic, some patterns of complementation exhibit uses that are difficult to link semantically and must therefore be viewed as homonyms
Ben, Kahla Haithem. "Sur des méthodes préservant les structures d'une classe de matrices structurées." Thesis, Littoral, 2017. http://www.theses.fr/2017DUNK0463/document.
The classical linear algebra methods, for calculating eigenvalues and eigenvectors of a matrix, or lower-rank approximations of a solution, etc....do not consider the structures of matrices. Such structures are usually destroyed in the numerical process. Alternative structure-preserving methods are the subject of an important interest mattering to the community. This thesis establishes a contribution in this field. The SR decomposition is usually implemented via the symplectic Gram-Schmidt algorithm. As in the classical case, a loss of orthogonality can occur. To remedy this, we have proposed two algorithms RSGSi and RMSGSi, where the reorthogonalization of a current set of vectors against the previously computed set is performed twice. The loss of J-orthogonality has significantly improved. A direct rounding error analysis of symplectic Gram-Schmidt algorithm is very hard to accomplish. We managed to get around this difficulty and give the error bounds on the loss of the J-orthogonality and on the factorization. Another way to implement the SR decomposition is based on symplectic Householder transformations. An optimal choice of free parameters provided an optimal version of the algorithm SROSH. However, the latter may be subject to numerical instability. We have proposed a new modified version SRMSH, which has the advantage of being numerically more stable. By a detailes study, we are led to two new variants numerically more stables : SRMSH and SRMSH2. In order to build a SR algorithm of complexity O(n³), where 2n is the size of the matrix, a reduction to the condensed matrix form (upper J-Hessenberg form) via adequate similarities is crucial. This reduction may be handled via the algorithm JHESS. We have shown that it is possible to perform a reduction of a general matrix, to an upper J-Hessenberg form, based only on the use of symplectic Householder transformations. The new algorithm, which will be called JHSH algorithm, is based on an adaptation of SRSH algorithm. We are led to two news variants algorithms JHMSH and JHMSH2 which are significantly more stable numerically. We found that these algortihms behave quite similarly to JHESS algorithm. The main drawback of all these algorithms (JHESS, JHMSH, JHMSH2) is that they may encounter fatal breakdowns or may suffer from a severe form of near-breakdowns, causing a brutal stop of the computations, the algorithm breaks down, or leading to a serious numerical instability. This phenomenon has no equivalent in the Euclidean case. We sketch out a very efficient strategy for curing fatal breakdowns and treating near breakdowns. Thus, the new algorithms incorporating this modification will be referred to as MJHESS, MJHSH, JHM²SH and JHM²SH2. These strategies were then incorporated into the implicit version of the SR algorithm to overcome the difficulties encountered by the fatal breakdown or near-breakdown. We recall that without these strategies, the SR algorithms breaks. Finally ans in another framework of structured matrices, we presented a robust algorithm via FFT and a Hankel matrix, based on computing approximate greatest common divisors (GCD) of polynomials, for solving the problem pf blind image deconvolution. Specifically, we designe a specialized algorithm for computing the GCD of bivariate polynomials. The new algorithm is based on the fast GCD algorithm for univariate polynomials , of quadratic complexity O(n²) flops. The complexitiy of our algorithm is O(n²log(n)) where the size of blurred images is n x n. The experimental results with synthetically burred images are included to illustrate the effectiveness of our approach
Mokrane, Abdellah. "Sur la structure de la cohomologie cristalline logarithmique des schémas semi-stables." Paris 11, 1992. http://www.theses.fr/1992PA112041.