Teses / dissertações sobre o tema "Structure de blocs courbe"
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Roche, Claire. "Hexahedral curved block-structured mesh generation for atmospheric re-entry". Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASG053.
Texto completo da fonteThe French Alternative Energies and Atomic Energy Commission (CEA) studies Computational Fluid Dynamics (CFD) in the case of supersonic and hypersonic flows. To do so, a dedicated code is developed. To deal with strong constraints, this code only performs on block-structured meshes. This specific type of mesh is complicated to generate, and this generation is usually handled by hand using dedicated interactive software. In the case of industrial complex geometries, the mesh generation is highly time-consuming. Currently, automatic hexahedral mesh generation is a complex open research field.In this thesis work, we propose a method to generate block-structured hexahedral meshes on curved blocks of the fluid domain around vehicles, dedicated for the problems of interest. This method is first proposed in 2D and then extended to 3D. Here, it is presented in the generic nD case. This method is composed of several steps. First, a linear block structure is extruded from a first vehicle surface discretization. This work is an extension of the previous work of Ruiz-Girones et al.. Once this linear block structure is generated, we propose two different methods to curve the block structure to improve the vehicle surface representation and limit the smoothing on the final mesh. The first method is through an algorithm of mesh adaptation at fixed topology by solving an optimization problem to which a penalty term is added to align certain mesh edges to an implicit interface. Our global approach uses this method to align the block structure to the vehicle surface. This method remains time-consuming in 3D, so we proposed a second method to curve our block structure through polynomial Bézier curves. Considering our blocks as Bézier blocks, we apply geometric and local operations to align the high-order block structure to the vehicle surface. Then, considering we curved the block structure using Bézier elements, we generate a mesh on the curved blocks under constraints. Finally, the generated mesh quality is evaluated in two ways. The first one is through purely geometrical criteria analysis. The second one is through numerical simulations of flows around vehicles on our meshes, comparing the simulation results to experimental data, analytical results, and reference simulations
Roos, Alexandra. "Copolymères à blocs : structure, rhéologie et propriétés adhésives". Paris 6, 2004. http://www.theses.fr/2004PA066492.
Texto completo da fonteDelhomme, Fabien. "Etude du comportement sous impact d'une structure pare-blocs en béton armé". Chambéry, 2005. http://www.theses.fr/2005CHAMS004.
Texto completo da fonteThis thesis studies the behaviour of a new concept for a protection gallery under rock fall, called Structurally Dissipating Rock-shed (SDR). The main innovation, compared to conventional solutions, is to dissipate the impact energy directly into the reinforced concrete slab or into fuse supports, and no longer in a cushion layer. The dynamic phenomena, taking place during the impact of a block onto the slab, are analyzed by means of experiments on a 1/3 scale SDR structure. The percussion loads applied to the slab, during the contact phase with the block, are assessed as weIl as the various energy transfers and dissipations. The results allowed to validate the operating and repair principles of the SDR and revealed that the slab is damaged by three main mechanisms: the punching, the bending and the breaking clown at surface level of the impacted zone. The principal experimental values are found by numerical simulations of the tests with a finite elements tool. A simplified mechanical model "masses-springs-damping" is also developed with the aim of implementing design methods for engineering offices. The prospects for this work are to succeed in establishing design and construction recommendations for structurally dissipating rock-sheds
Virgiliis, Afonso Luís Corrêa de. "Procedimentos de projeto e execução de pavimentos permeáveis visando retenção e amortecimento de picos de cheias". Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3138/tde-08092010-122549/.
Texto completo da fonteThe present work intents to show design and built procedures, of porous pavements; by paying attention on its practical appliances as compensatory option in urban drainage with purpose to retaining rainfall water by storage, reducing downstream flooding in cities with great urban density. The procedures here proposed are based in the know how acquired for the construction of two kinds of porous pavements: one built with interlocked concrete blocks and the other built with porous asphalt. In order to aid the present work, an experimental field was built as parking area inside the propriety of CTH Centro Tecnologico de Hidraulica in State University of Sao Paulo where the tests and experiments were made. The parking area is a reservoir structure where rain water is stored inside courses of aggregates. The storage volume is in the void space between particles of material that comes by infiltration trough the pavement layer. The commendation, after the studies, is that procedures and activities of design and build of porous pavements could be observed by government and private sector as alternative solution in many kinds of urban projects such as large public and private lots, parking areas sport fields side walks and streets, with low capacity of traffic loads, and so forth.
Vetrivel, Iyanar. "Exploring new applications of a structural alphabet in protein structure analyses". Thesis, Nantes, 2017. http://www.theses.fr/2017NANT1017/document.
Texto completo da fonteStructural motifs found in protein structures. They help in approximating protein structure as a 1D string with minimal loss of structural information. Here I have employed a widely used structural alphabet called Protein Blocks (PB) for various applications like predicting, comparing and analyzing protein structures. PBs were used to study the structural variations in proteins with identical primary structure and also during the course of molecular dynamics (MD) simulations. The results from these analyses were summarized in the form of substitution matrices and showed striking similarities to previously established matrices for homologous proteins and NMR ensembles. I improved kPRED, a knowledge-based prediction of protein backbone in terms of PBs, by taking into consideration the neighboring local structures. The new version of the algorithm also privileges structural information from homologous proteins when available reaching an average accuracy of 66.3% on a benchmark dataset. The scope of the PENTAdb database has been expanded to cover the entire protein structure space in an automated manner. I show that the effect of this 950% increase in the contents of PENTAdb improves our understanding of the sequence-structure relationship at the pentapeptide level. I also used PB-ALIGN, a fast and efficient protein structure comparison tool, to compare all protein structures in PDB in an all-vs-all manner and to investigate PB-based structural similarities. This generated a huge collection of alignment data and I discuss its use for functional annotation and identification of possible evolutionary relationships
COURT, FRANCOIS. "Effet cotensioactif dans des melanges de copolymeres a blocs relations structure chimique / microstructure / proprietes". Paris 6, 1996. http://www.theses.fr/1996PA066101.
Texto completo da fonteMaiez-Tribut, Sara. "Relations entre la structure d'un copolymère à blocs et la nanostructuration d'un polymère réticulé". Lyon, INSA, 2007. http://theses.insa-lyon.fr/publication/2007ISAL0004/these.pdf.
Texto completo da fonteIntroduction of block copolymers as reinforcing agents in thermoset is increasing. The block copolymer ability to nanostructure this kind of matrix allows to obtain good mechanical properties. But the difficulty is to obtain such nanostructure which depends on miscibility of each block versus the growing network. Indeed, in order to avoid any kind of macrophase separation wich could deteriorate mechanical properties, one block must remain miscible in the system up to the end of the reaction to stabilize the formed structure. Since a polymer is generally miscible with only few systems, so, each block copolymer has to be adapted to each specific matrix. The main aim of this work has been to determine the composition of a block copolymer able to nanostructure epoxy networks with different polarities: DGEBA-DDS and DGEBA-MCDEA. In order to identify an homopolymer which could remain miscible with these two matrixes up to the end of the reaction, we realised a miscibility study and we showed that the poly(dimethylacrylamide) is an excellent candidate: as a result we associated it with MMA units to form a random copolymer. Having identified the stabilizing block, ABA and AB block copolymers have been synthesized. Their behaviour in the epoxy precursors and in particular the localisation of the order-disorder transition in the obtained blends, have been studied: this latter property appeared to be influenced by the blend composition. We were also interested in blends organization before and after the reaction (analyses performed by TEM and SAXS), and in its evolution during the polymerization (monitored by SAXS). Finally, the reinforcement effect of ABA block copolymers has been evaluated. A toughness improvement of the epoxy networks, without significant increase of the glass transition temperature, has been observed
Maiez-Tribut, Sara Pascault Jean-Pierre. "Relations entre la structure d'un copolymère à blocs et la nanostructuration d'un polymère réticulé". [S.l.] : [s.n.], 2007. http://docinsa.insa-lyon.fr/these/pont.php?id=maiez-tribut.
Texto completo da fonteGhesquiers, Philippe. "Structure spatiale de commandabilité, placement de directions propres et découplage par blocs des systèmes linéaires". Toulouse, ENSAE, 1990. http://www.theses.fr/1990ESAE0006.
Texto completo da fonteMeyer, Nicolas. "Une Nouvelle voie de synthèse de copolymères a blocs, de structure en étoile, du type A3B". Mulhouse, 2001. http://www.theses.fr/2001MULH0667.
Texto completo da fonteLe, Hir Maryvonne. "Les champs de blocs intertidaux à la pointe de Bretagne (France) : biodiversité, structure et dynamique de la macrofaune". Brest, 2002. http://www.theses.fr/2002BRES2013.
Texto completo da fonteThe spatial variability of macrofaunal community in boulder fields was described. The distribution of organisms at a small scale (dmø) was first analysed. Results revealed a hierarchical structure in the community, which was organised in three sub-communities and eight microcommunities. Vertical variability of the community was then observed along the hypsometric gradient. The well-known intertidal zonation of the fauna was blurred, depending on the boulder arrangements, which determined quantity and quality of shelter for organisms. Spatial variability was studied at regional scale (100 km). Three sites were compared. Results showed a great variability of the abundance and biomass values. Trophic structures expressed in terms of abundance showed a vertical (hypsometric) and horizontal (inter-sites) variability. They directly depended on environmental variations. Trophic structures expressed in terms of species richness showed a vertical variability, but were stable between sites at the same hypsometric level. They revealed the existence of a common regional pool of species, structured as a regional metacommunity. Secondly, community dynamics were studied for two years at one site. Results show a stochastic variability of the abundance, biomass and species richness. Moreover, arrivals of macroalgal debris on the shore enhanced the ecological parameters of each trophic level, but the global trophic structure was not changed. Intertidal macrofaunal communities are adapted to use algal debris as a trophic resource, and then may have a major role in recycling this important primary production in temperate waters. Finally, experimental studies were carried out to assess the impact of habitat disturbance on the macrofaunal community. The mobile part of the community seemed resistant to the experimental disturbance. However the sessile part, which encompassed ascidians, bryozoans and sponges, was impacted
Lorentz, Julien. "Etude de la capacité de dissipation sous impact d'une structure sandwich de protection contre les chutes de blocs rocheux". Phd thesis, Université Joseph Fourier (Grenoble), 2007. http://tel.archives-ouvertes.fr/tel-00143778.
Texto completo da fonteDemazeau, Maxime. "Relations structure-effet de nanovecteurs à base de copolymères à blocs pour la thérapie photodynamique : utilisation de modèles de membranes". Electronic Thesis or Diss., Toulouse 3, 2019. http://www.theses.fr/2019TOU30113.
Texto completo da fontePhotodynamic therapy (PDT), a therapy based on the irradiation of photosensitizing molecules to generate an oxidative stress, is already used as a treatment of some pathologies. The photosensitizers used are often highly hydrophobic molecules that aggregate in aqueous medium. Therefore, used by themselves, they require to be injected at high concentrations, leading to a risk of global photosensitization. To reduce this secondary effect and increase the effectiveness of the treatment, it is possible to encapsulate those molecules. Previous work in the IMRCP laboratory has led to the development of block copolymer-based carriers to encapsulate a photosensitizer, pheophorbide-a. This work has showed superior efficiency of some type of carriers compared to others under PDT conditions on cell culture. The aim of this project was to develop tools to better understand the mechanisms occurring when using block copolymers-based nanocarriers encapsulating pheophorbide-a and during the irradiation of the photosensitizer. The nanocarriers studied were block copolymer-based micelles made of PEO-PCL, PEO-PLA and PEO-PS. To simplify the system studied, we chose to use liposomes as membrane models to simulate the biological target. Using the fluorescence properties of pheophorbide-a, we were able to obtain the affinity constants of the photosensitizer for the micelles and the lipid vesicles, and then evaluate the transfer of pheophorbide-a from the micelles to the vesicles. Following that, we investigated the phenomena occurring during the irradiation of the photosensitizer. We were able to estimate the relative production of singlet oxygen depending on the type of micelles used. By monitoring the leakage of a fluorescent probe contained in the liposomes, allowing us to evaluate their permeability, it was possible to measure the effects of singlet oxygen production on the integrity of the liposome membrane. Complementarily, we followed the oxidation of the lipids of the liposomes during the irradiation of pheophorbide-a by mass spectrometry. These results combined together allowed us to see what were the parameters influencing the PDT efficiency of micelles encapsulating a photosensitizer. We managed to classify those with the greatest effect on the integrity of model membranes among those studied
Weisbecker, Clement. "Amélioration des solveurs multifrontaux à l'aide de représentations algébriques rang-faible par blocs". Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2013. http://tel.archives-ouvertes.fr/tel-00934939.
Texto completo da fonteMeyfredi, Jean-Christophe. "Détermination de la courbe de structure par terme des taux d'intérêt, prise en compte du risque et évaluation des obligations convertibles". Aix-Marseille 3, 2000. http://www.theses.fr/2000AIX32066.
Texto completo da fonteOuattara, Mory. "Développement et mise en place d'une méthode de classification multi-blocs : application aux données de l'OQAI". Electronic Thesis or Diss., Paris, CNAM, 2014. http://www.theses.fr/2014CNAM0914.
Texto completo da fonteThe multiplication of information source and the development of news technologies generates complex databases, often characterized by relatively high number of variables compared to individuals. In particular, in the environmental studies on the indoor air quality, the information's collection is done according to several thematic, yielding column partitioned or multi-block data set. However, in case of high dimensional data, classical clustering algorithms are not efficient to find clusters which may exist in subspaces of the original space. The goal of this work is to develop clustering algorithms adapted to high dimensional data sets with multi-block structure. The first part of the work shows the state of art on clustering methods. In the second part, three new methods of clustering: the subspace clustering method 2S-SOM (Soft Subspace-Self Organizing Map)is based on a modified cost function of the Self Organizing Maps method across a double system of weights on the blocks and the variables. Then we propose two approaches to find the consensus of self-organized maps CSOM (Consensus SOM) and Rv-CSOM based on weights determined from initial partitions. The last part presents an application of these methods on the OQAI data to determine a typology of dwellings relatively to the following topics: indoor air quality, dwellings structure, household characteristics and habits of the inhabitants
Jullian, Nicolas. "Étude expérimentale de la relation entre rhéologie et structure de copolymères à blocs à base d’acrylate. : Apport pour la formulation des autoadhésifs". Pau, 2009. http://www.theses.fr/2009PAUU3017.
Texto completo da fonteIn this work, we studied the effect of nanostructure of block copolymers on their rheological behaviour and proposed new solutions for self-adhesive formulations. Thereby, we synthesized by controlled radical polymerization di- and triblock soft copolymers composed of poly(n-butyl acrylate) (PnBA) and polystyrene. The segregation of these materials is very difficult to obtain due to the low value of the PnBA/PS Flory-Huggins interaction parameter. However, when the segregation is effective, bicontinuous, cylindrical and spherical morphologies are observed depending on the molecular mass, the composition and the polydispersity index (PDI). Moreover, these morphologies greatly influence the viscoelastic behaviour of these materials. In particular, we demonstrate the existence of limit values concerning the molecular mass and the PDI of these materials in obtaining appropriate viscoelastic properties for applications in self-adhesives formulations. Given that, these limits are very difficult to achieve in an industrial context, we propose alternate solutions such as substituting the PS blocks by poly(methyl methacrylate) or adding PnBA homopolymers. In order to model the rheological behaviour of these block copolymers, a series of analogous PnBA homopolymers were prepared and studied. Finally, the adherence properties of block copolymers based formulations are analyzed and compared with those of a commercial formulation with respect to their viscoelastic properties
Santanach, Carreras Enric. "Stabilité en extrusion des polymères fondus : effets de la pression et de la structure des copolymères triblocs de type ABA". Phd thesis, Université Joseph Fourier (Grenoble), 2005. http://tel.archives-ouvertes.fr/tel-00011316.
Texto completo da fonteLa présente thèse a pour objectif de mieux connaître l'influence des paramètres de pression et contrainte sur les propriétés des polymères et la stabilité de leurs écoulements, et ce en relation avec leur structure mésoscopique.
Les effets de la pression ont été étudiés sur quatre polyéthylènes (PE) de structures différentes. D'abord, les conditions expérimentales précises ont été définies pour isoler les effets de la pression des effets de la température et pour différencier les écoulements stables ou instables. Nos résultats montrent que les effets de la pression sont les mêmes en cisaillement et en élongation, sauf pour l'un des PE où ils sont 30% supérieurs en cisaillement. En outre, c'est un critère de contrainte critique qui caractérise l'apparitions des instabilités viscoélastiques quelle que soit la pression moyenne.
Dans la deuxième partie de cette thèse, trois copolymères de la famille des SEBS montrant une séparation de phase aux échelles nanoscopiques ont été considérés. L'étude des défauts macroscopiques d'extrusion, et de la propagation de fissures surfaciques, de ces copolymères à blocs a permis d'identifier l'origine du défaut dit de « refente d'extrudat » ainsi qu'un nouveau régime d'extrusion : le « pelage continu ». Ces défauts ont été mis en relation avec la structure mésoscopique par des essais de diffusion de rayons-X aux petits angles.
Masson, Olivier. "Etude des défauts de structure par diffraction des rayons X sur poudres : Utilisation d'un montage en réflexion asymétrique équipé d'un détecteur courbe à localisation". Limoges, 1998. http://www.theses.fr/1998LIMO0008.
Texto completo da fonteOuattara, Mory. "Développement et mise en place d'une méthode de classification multi-blocs : application aux données de l'OQAI". Phd thesis, Conservatoire national des arts et metiers - CNAM, 2014. http://tel.archives-ouvertes.fr/tel-01062782.
Texto completo da fonteMorand, Marion. "Surface de symétrie d’une structure 3D : application à l’étude des déformations scoliotiques du dos". Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTS107.
Texto completo da fonteIn this thesis we are interested in the study of the symmetry of 3D meshes. Usually, this is defined as an orthogonal symmetry with respect to a plane. However, this characterisation is only fully relevant in case of "straight" bilateral structures. For our case about scoliotic deformations of the back surface, the analysis of asymmetries is very imprecise.Therefore we propose to generalise the notion of 3D mesh symmetry by defining an orthogonal symmetry with respect to any non-planar surface.After having studied the limits of plane symmetry, we suggest a new method to calculate a surface of symmetry for a 3D mesh. This iterative algorithm is based on the decomposition of the studied structure into a set of adaptive bands, defined orthogonally to a symmetry curve, and then on the calculation of local symmetry planes for each of these bands. These bands are later interpolated to obtain the surface of symmetry. A particular focus is put into the robustness of the algorithm, which must be able to adapt to the various possible deformations of the mesh.We then propose a method able to compute a curved and standardised asymmetry map from the surface of symmetry.Lastly, we present an application of our contributions for the study of scoliosis-induced deformities.We then show that the study of the surface of symmetry of the back makes it possible to categorise the different types of scoliosis and build a 3D model of the spine, without resorting to radiative imaging
Aubrée, Marc. "Analyse expérimentale du sillage et des efforts locaux produits par un écoulement uniforme sur une structure courbe de section circulaire : contribution à l'étude de la trainée des cables". Le Havre, 1993. http://www.theses.fr/1993LEHA0006.
Texto completo da fonteGernigon, Véronique. "Utilisation de copolymères à blocs dans les cellules solaires organiques : morphologie, transport de charges et conversion photovoltaïque". Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00744967.
Texto completo da fonteJahangir, Emad. "Phénomènes d'interaction sol-structure vis-à-vis de l'aléa retrait-gonflement pour l’évaluation de la vulnérabilité des ouvrages". Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL088N/document.
Texto completo da fonteClayey soils can present large volumetric deformations in response of water content change. This phenomenon of shrinkage and swelling of clayey soils is recognized as a costly natural hazard throughout the world. In France, this cost is reported between 1988 and 2007 to 5 million Euros, ranking in second class of the French natural hazards in terms of cost of damage after the floods. The individual masonry buildings with shallow foundations are the most affected by this phenomenon that causes a differential settlement of the building leading to cracks in facades and structural elements, especially in unreinforced masonry elements.The objective of this thesis was to study the vulnerability of the building, against the shrink-swell hazard through an analysis of soil-structure interaction. This work was focused on three major points: - Hydro-mechanical behavior of clay soils - Soil-structure interaction - Evaluation of structural damage.The hydro-mechanical behavior of clay soils was considered by the concept of state surface and integrated into a soil-structure interaction model, based on the Winkler model, with increasingly complex approaches: 1D, 2D and 3D by modeling the building behavior respectively by a spring system, the beam element and the plate element. These models of soil-structure interaction are able to calculate the relative deflection of the building, according to the values of imposed suction, mechanical properties of the structure and hydro-mechanical properties of the soil. The relative deflection of the building is then compared to threshold values of the classical damage categories to assess the building damage.Finally a feasibility study was conducted on the development of vulnerability curves adapted to the problem of shrinkage – swelling of clayey soils. These curves represent the average of structural damage versus suction, for each type of building. These curves were developed based on a classification of expansive soils and a building typology outcome from databases of affected buildings. The average damage is calculated by the Monte-Carlo method, taking into account the variability of the building parameters
Jahangir, Emad. "Phénomènes d'interaction sol-structure vis-à-vis de l'aléa retrait-gonflement pour l'évaluation de la vulnérabilité des ouvrages". Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2011. http://tel.archives-ouvertes.fr/tel-00674052.
Texto completo da fonteBernard, Maud. "Les habitats rocheux intertidaux sous l'influence d'activités anthropiques : structure, dynamique et enjeux de conservation". Phd thesis, Université de Bretagne occidentale - Brest, 2012. http://tel.archives-ouvertes.fr/tel-00720611.
Texto completo da fonteEscalé, Pierre. "Elaboration de films nid d'abeille hiérarchiquement structurés à partir de copolymères : synthèse, structuration et propriétés de surface". Thesis, Pau, 2012. http://www.theses.fr/2012PAUU3027/document.
Texto completo da fonteThe present studies aim at designing hierarchically structured porous surface from copolymers with well defined structures. As a science in constant evolution, polymer chemistry, enable the synthesis of diblock copolymers with different natures by the mean of various radical controlled polymerization techniques. Indeed, radical controlled polymerization with nitroxyde (NMP), by atom transfer (ATRP), by reversible addition/fragmentation transfer (RAFT) or by Cu(0) were used for the synthesis of diblock copolymers based on polystyrene and different acrylates or 4-vinylpyridine blocks. The intimately association between a fast solvent evaporation process named the Breath Figure and the synthesis of the copolymers enable the production of hierarchically structured materials from micro to nanoscale. The nature of the different blocks confers adhesion, wettability or bioactivity properties to these materials. These researches benefit from the chemistry and physico-chemistry laboratory competences. Indeed, microscopy techniques (optical, atomic force and electronic), scattering (small angle neutron or X-ray) as well as tack or wettability measurements enable the complete characterization of films structuration and point up their properties
Deeb, Maha. "Influence des plantes, des vers de terre et de la matière organique sur la structure de technosols construits". Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1014.
Texto completo da fonteConstructed Technosols are mixtures of technogenic materials used to create a new soil dedicated to growing plants. Constructed Technosols provide an opportunity to recycle and optimally use urban waste, and are an alternative to the use of agricultural soils for producing urban soils. This work is assessing in particular the influence of the OM levels and interactions with earthworms and plants on the physical properties of Constructed Technosols. The materials used to build our Technosols are compost and excavated deep horizons. In a first experiment, we tested the influence of OM rates on hydrostructural properties of Technosols, realizing 6 Mixtures of increasing volume proportions of compost (0 to 50%). The shrinkage and retention curves show that the hydrostructural properties of Technosols are similar to those of natural soils. Increasing the amount of organic material is accompanied with a positive effect on micro and macro porosity, as well as on the water available for plants.Secondly, these mixtures were incubated in a growth chamber with or without earthworms (Aporrectodea caliginosa) and with or without plants (Lolium perenne). After 5 month of experiment, we measured hydrostructural properties, aggregation, and distribution of carbon in each fraction. The presence of plants and / or earthworms explains 19% of the variance of hydrostructural properties of the soil, and compost dose affects 14%. The interaction between organisms and compost further explains the variance (40%) than the effects of these individual factors. Compost and plants play a positive role in the available water by acting on both macroporosity and microporosity, while earthworms play a positive role only on the latter. Furthermore, the proportion of aggregates >3 mm is more important in the treatments control and earthworms, while the proportion of aggregates <3mm is greater in the presence of plants, regardless of the presence of earthworms. Organisms have a stronger effect on the structural stability (77%) than compost (4%). All have a positive effect on the amount of Corg in the different fractions of aggregates. Finally, mineralization of Corg increases in the presence of worms or compost, but decreases in the presence of plants. Our results demonstrate the interest of enhancing urban materials such as excavated deep horizons and compost to build Technosols. A summary of the results allows us to recommend a volume content of compost between 20 and 30% for a good structure, without increasing much the cost induced by compost. Noting the positive effect of earthworms, plants and earthworms/plants interactions on porosity, structural stability and carbon storage, it seems appropriate to favor the presence of organisms
Bourova, Ekaterina. "Etude de la structure lithosphérique par l'analyse d'ondes de surface dans deux zones de convergence : la mer Egée et l'Iran". Phd thesis, Université Joseph Fourier (Grenoble), 2004. http://tel.archives-ouvertes.fr/tel-00721460.
Texto completo da fonteBreugnot, Antonin. "Approche numérique couplée discret-continu appliquée aux ouvrages cellulaires impactés". Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00634430.
Texto completo da fonteMiguel-Arricau, Sophie. "Corrélation structure/propriété de polymères à base d'acrylamide pour des applications en récupération assistée des hydrocarbures (RAH)". Electronic Thesis or Diss., Pau, 2022. https://theses.hal.science/tel-04010751.
Texto completo da fonteThe knowledge of the physico-chemical properties of polymer solutions for enhanced oil recovery (EOR) is crucial to optimize the process. The purpose of this work was to consolidate and complete an universal viscosity model depending on C[η] parameter. The later allows taking into account the degree of interpenetration of polymer chains (critical concentration, C*, diluted and semi-diluted solutions). Various polymer parameters have been studied as the effects of microstructures, polymer size (molar mass and dispersity) as well as chemical composition. A library of polymer models was elaborated by controlled radical polymerization (RADT/MADIX). Series of polyacrylamides, statistical and asymmetric copolymers of acrylamide-sodium acrylate and post-hydrolyzed polyacrylamides were synthesized and characterized by steric exclusion chromatography and capillary rheology and the analytical protocols and techniques were optimized. The effects of the microstructure onto dimensional, rheological and complexation physico-chemical properties were determined
Burtscher, Annegret Yvonne. "Analytic and geometric aspects of spacetimes of low regularity". Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066345.
Texto completo da fonteThe general theory of relativity describes the effect of gravitation in terms of the geometry of spacetimes. The curvature of Lorentzian manifolds is related to the energy and momentum of matter (or vacuum) by the Einstein equations, a system of nonlinear partial differential equations. In the 1950s the initial value formulation and local existence of solutions to the Einstein equations were established. As of yet the global structure of spacetimes is much less understood. Motivated by this I investigate the evolution as well as the regularity of spacetimes. I show that certain energy estimates can be controlled by one-sided bounds on the geometry only. Estimates of the Bel-Robinson energy, for example, play a crucial role in the derivation of breakdown criteria for solutions of the vacuum Einstein equations. As an important astrophysical model spacetimes with perfect fluid sources are considered. An existence theory for spherically symmetric solutions to the Einstein-Euler equations is presented, and, above all, I identify for the first time a class of untrapped initial data that leads to the dynamical formation of trapped surfaces. To allow for shock waves, solutions are regarded to be of bounded variation. The distributional framework is essential here and in other areas of general relativity, and it is crucial to understand if and how the regularity of metrics influences the geometry of spacetimes. I account for this by deriving some general results on continuous Riemannian metrics and algebras of generalized functions. This thesis thus illustrates that spacetimes of low regularity exhibit a wide range of interesting phenomena during their evolution
Gomes, Benros Cristina. "Analyse et prédiction des structures tridimensionnelles locales des protéines". Paris 7, 2005. http://www.theses.fr/2005PA077090.
Texto completo da fonteGuaus, Anaïs. "Analyse linéaire des instabilités dans les écoulements incompressibles à parois courbes compliantes". Toulouse 3, 2008. http://thesesups.ups-tlse.fr/203/.
Texto completo da fonteA compliant wall is a wall that is flexible enough to be deformed by the stress created by a flow. It is now proven that the stability of a flow over a compliant wall can be considerably modified compared with the rigid-wall case. In particular, the destabilization of Tollmien-Schlichting waves, responsible for the transition to turbulence when the flow is only weakly perturbed, can be delayed. In this study, the linear stability of two flow configurations containing curved compliant walls, a curved channel flow and a Taylor-Couette flow, has been investigated. Both flows are exposed to a centrifugal instability mechanism which promotes the apparition of contra-rotative vortices. At the moment there are very few studies concerning the influence of compliant walls on the centrifugal instabilité mechanisms. The compliant walls are modelled as thin cylindrical shells supported by a rigid outer frame through arrays of springs and dampers; this is often referred to as Kramer-type coating. In addition to the numéral resolution of an eigenvalue problem, an asymptotical study of the flow stability in the curved channel has been performed for the case of large-wavelength transverse perturbations. Results show that only very flexible walls have an influence on the flow stability, mainly by destabilizing the large-wavelength perturbations. The generation of four hydroelastic modes is allowed by wall compliance where these instabilities can precede the centrifugal one. Additionally, exchanges between stable hydroelastic and centrifugal modes have been observed
El, hellani Ahmad. "Evaluation of The Electronic Properties of Carbon(0)-Based Compounds Through Gold Catalysis and X-Ray Structure Analysis". Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112252.
Texto completo da fonteMost organic compounds which are stable in the condensed phase contain tetravalent carbon atoms, where all four valence electrons are being engaged in chemical bonds. On the other hand, the chemistry of divalent carbon(II) was only recognized after the isolation of a stable persistent carbene by Bertrand and co-workers in 1985. Such products display one s-type lone pair orbital and are thus good ligands. Earlier on, concern was also paid to a new family of compounds, first reported in 1961 by Ramirez and co-workers. They can be considered as divalent carbon(0) derivatives with two lone pairs at the central carbon, with a possibility of double coordination of two Lewis acids to this carbon. This feature was proposed by Kaska in 1973, and verified later by the isolation of di-metalated adducts. From 2006, these compounds were the centre of extensive theoretical investigations by Frenking, which led to the isolation of new members of this family by Fürstner and Bertrand. This family is now referred to as “carbones”, of general formula CL2 (L =PR3 or carbene).“Carbones” are still virtually unused in catalysis. Thus, we have decided to study these derivatives, especially in the field of gold catalysis, and to compare them with well-known ligands such as NHCs, phosphines and phosphites. Recently, we were able to synthesize their corresponding GaCl3 complexes and to rationalize their electronic properties through Gutmann’s rules for Lewis acid/Lewis base adducts. In addition, we obtained some ionic “dimers” and we explained their formation on the basis of ligand’s electronic properties. We have shown through these two approaches that carbones are far better donors than NHCs
Bernard, Maud. "Les habitats rocheux intertidaux sous l'influence d'activités anthropiques : structure, dynamique et enjeux de conservation". Electronic Thesis or Diss., Brest, 2012. http://www.theses.fr/2012BRES0010.
Texto completo da fonteRecreational and professional activities are intensifying on the rocky intertidal. The overturning of boulders and the trampling associated with human activities, have consequences on the structure and dynamic of rocky intertidal communities. Through the identification of species and descriptors that respond more to the disturbances “trampling of mediolittoral rock platforms” and “the overturning of low eulittoral boulders by hand-fishermen”, SMART indicators (Simple, Measurable, Achievable, Realistic, and Time limited indicator) can be created for the assessment of the conservation status of these habitats. The effects of trampling were tested with control approach. Experiments in situ underlined very complex interactions between species during the ecological processes of degradation of biocenoses. High thresholds of disturbance were also observed. They were particularly related to the protection played by structuring brown algae on other species. The study of boulder’s overturning highlighted a step of almost total mortality of fixed or low mobile organisms that live on upper or lower surfaces of boulders. Results also showed a low resilience of the habitat. The use of appropriate reference situations and of the most sensitive species to the boulder’s overturning, led to the creation of two ecological indicators. Declined to two different spatial scales, they may be applied routinely by scientists and managers of marine protected areas
Belattar, Adel. "Analyses multi-échelles du comportement et la durée de vie d'aciers inoxydables 304L sous sollicitations cycliques avec pré-écrouissage". Phd thesis, INSA de Rouen, 2013. http://tel.archives-ouvertes.fr/tel-00819298.
Texto completo da fonteNougué, Odrade. "Ecologie évolutive des limites de niche : cas de l’adaptation à la salinité de l'artémie". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS262/document.
Texto completo da fonteHutchinson defined the niche concept as the multidimensional space of environmental variables where the specie survives. During this work, I focused on several conceptual and operational limits of this concept. Basing our work on the adaptation to salinity of the genus Artemia – an extremophile branchipod – we studied: (i) mechanisms involved in the polymorphism maintenance in a large clonal population, which asked the question of the scaling in the use of the niche concept; (ii) impact of the gut microbiota on the adaptation to low salinities, which asked the question on the impact of biotic interactions on the niche; (iii) the effects of habitat quality and phenotypic plasticity on the tolerance to high salinities, which asked operational questions on the evaluation of theses factors and there impact on the niche. The work detailed in this manuscript is based on a large variety of methodologies and helped providing elements of answers to solve the problematic. First, we showed that the important diversity found in the large clonal population was structured by environmental variables such as salinity and temperature. Therefore, in the case of a large asexual population, the niche concept can apply to a group of genetically close individual that might share (depending on the reproduction mode) common ancestry. Then, we showed that the niche of the gut microbiota, associated with Artemia for algae digestion, constrained their host tolerance to low salinities. Thus, biotic interactions may have different effects (even conflicting sometimes) on the different axes of their host niche. Finally, we provided some methodological solutions to evaluate separately the impact of plasticity and habitat quality on the adaptation of Artemia to high salinities. In the end, we provided conceptual and/or operational solutions that strengthen the evolutionary ecology key concept of the niche
Mahajan, Swapnil. "Applications d'un alphabet structural pour l'analyse, la prédiction et la reconnaissance des repliements des protéines". Thesis, La Réunion, 2013. http://www.theses.fr/2013LARE0032.
Texto completo da fonteAnalysis of protein structures using structural alphabets has provided new insights into protein function and evolution. We have used a structural alphabet called proteins blocks (PBs) which efficiently approximates protein backbone and allows abstraction of 3D protein structures into 1D PB sequences. This thesis describes applications of PBs for protein structure analysis, prediction and fold recognition. First, PBs were used to provide a refined view of structurally variable regions (SVRs) in homologous proteins in terms of conformationally similar and dissimilar SVRs in which were compiled a database of structural alignments (DoSA). We also show that the inherent conformational variations in loop regions are not correlated to corresponding conformational differences in their homologues. Second, to further analyze sequence-structure relationships in terms of PBs and other structural features, we have set up a database of pentapeptides derived from protein structures. This served as a basis for the knowledge-based prediction of local protein structure in terms of PB sequences (PB-kPRED) and of local structure plasticity (PB-SVindex). We demonstrate the successful applications of PB-kPRED for fold recognition and explored possible identification of structural and functional hotspots in proteins using PB-SVindex. Finally, an algorithm for fold recognition using a structural alphabet (FoRSA) based on calculation of conditional probability of sequence-structure compatibility was developed. This new threading method has been successfully benchmarked on a test dataset from CASP10 targets. We further demonstrate the application of FoRSA for fast structural annotations of genomes
Belattar, Adel. "Analyses multi-échelles du comportement et la durée de vie d’aciers inoxydables 304L sous sollicitations cycliques avec pré-écrouissage". Thesis, Rouen, INSA, 2013. http://www.theses.fr/2013ISAM0004/document.
Texto completo da fonteThis study investigates the effects of loading history on the cyclic stress-strain curve and fatigue behavior of 304L stainless steel at room temperature. Tension-compression tests were performed ont the same specimen under controlled strain, using several loading sequences of increasing or decreasing amplitude. The results showed that fatigue life is significantly reduced by the previous loading history. A previously developed method for determining the effect of prehardening was evaluated. Microstructural analyses were also performed; the microstructures after preloading and their evolution during the fatigue cycles were characterized by TEM. The results of these analyses improve our understanding of the macroscopic properties of 304L stainless steel and can help us identify the causes of failure and lifetime reduction
Yin, Kexin. "Influence of clay fraction on the mechanical behavior of a soil-concrete interface". Thesis, Ecole centrale de Nantes, 2021. http://www.theses.fr/2021ECDN0015.
Texto completo da fonteIn geotechnical engineering, the soil-structure interface is an important aspect to take into account in soil structure interactions because it relates to the stability of the supported structure. In particular, the mechanical behaviour of the interface plays a key role in the design of civil engineering structures and their analysis over time. The interface is a thin zone of soil in contact with the structure where major stresses and strains develop in. To our knowledge, previous works on the characterization of the mechanical behaviour of the soil-structure interface mainly include typical soils (sand or clay) or natural soils, in contact with variable structural materials (concrete, steel, wood). However, natural soils are very complex, partly due to geological heterogeneities, and the mechanical response of typical soils do not always represent accurately intermediate soils between sand and clay. Previous studies on the mechanical behavior of those soils are significantly represented in the literature, especially in experimental research, however it is rather poorly documented on the interface between these soils and structural materials, whereas their response to mechanical loadings is different. Moreover, at the engineering scale, there is still a lack of understanding on how this interface behave along loaded pile within soils between sand and clay, numerically, and experimentally due to instrumentation restrictions along the pile. The objective of this thesis is to characterize the mechanical behaviour of the soil-structure interface for intermediate soils between sand and clay, both by experiments at the laboratory scale and by models at the engineering scale. Artificial mixtures of silica sand and kaolinite-rich clay are chosen to represent intermediate soils in this study. For this propose, the research is organized in a first and main experimental campaign that aims to investigate the effect of the clay content, from 0% (sand) to 100% (clay) on the mechanical behavior of a soil-concrete interface by a new interface direct shear device in the laboratory. A particular attention is given to the design of the setup, and to the investigation of four sample preparations to insure an optimize sample homogeneity. A second and numerical campaign is performed to input the results from the experimental campaign, to model the mechanical response of the interface between sand-clay soils and a lateral concrete loaded pile at the engineering scale. A new subroutine of a MATLAB finite element code is implemented to perform the numerical modelling of the interface’s response via the p-y curves. The characterization of the mechanical behaviour of the soil-structure interface at different clay and sand fractions allows to enlighten the role of soil microstructure at the soil-structure interface on the stability of civil engineering structures
Akpama, Holanyo Koffi. "Approche multi-échelles pour une prédiction fiable de la ductilité des matériaux métalliques". Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0025/document.
Texto completo da fonteThe main objective of this PhD thesis is to develop a numerical tool capable of predicting the ductility of polycrystalline materials. This tool is based on the coupling of the self-consistent multiscale approach with two plastic instability criteria: the bifurcation theory and the initial imperfection approach. The self-consistent scheme is used to derive the mechanical behavior of a polycrystalline aggregate (assumed to be representative of the studied material) from that of its microscopic constituents (the single crystals). The constitutive framework at the single crystal scale follows a finite strain rate-independent formulation. Two different versions of the Schmid law are successively used to model the plastic flow: the classical version and a regularized one. To solve the constitutive equations at the single crystal scale, two numerical algorithms have been developed: one is based on the usual return-mapping scheme and the other on the so-called ultimate scheme. The equations governing the self-consistent approach have been revisited. To solve these equations, a new numerical scheme has been developed, which is shown to be more efficient than the existing schemes commonly based on the fixed point method. Also, a robust numerical approach has been developed to couple the self-consistent model to the initial imperfection approach. The performance and the robustness of the different numerical schemes and algorithms developed have been highlighted through several simulation results. The impact of various parameters and modeling choices on the formability prediction of sheet metals has been extensively analyzed
Lorenz, Jacqueline. "Le dogger du berry : contribution a la connaissance des plates-formes carbonatees europeennes au jurassique". Paris 6, 1989. http://www.theses.fr/1989PA066323.
Texto completo da fonteCebrecos, Ruiz Alejandro. "Transmission, reflection and absorption in Sonic and Phononic Crystals". Doctoral thesis, Universitat Politècnica de València, 2015. http://hdl.handle.net/10251/56463.
Texto completo da fonte[ES] Los cristales fonónicos son materiales artificiales formados por una disposición periódica de inclusiones en un medio, pudiendo ambos ser de carácter sólido o fluido. Controlando la geometría y el contraste de impedancias entre los materiales constituyentes se pueden controlar las propiedades dispersivas de las ondas. Cuando una onda propagante se encuentra un medio con diferentes propiedades físicas puede ser transmitida y reflejada, en medios sin pérdidas, pero también absorbida, si la disipación es tenida en cuenta. La presente tesis está dedicada al estudio de diferentes efectos presentes en cristales sónicos y fonónicos relacionados con la transmisión, reflexión y absorción de ondas, así como el desarrollo de una técnica para la caracterización de sus propiedades dispersivas, descritas por la estructura de bandas. En primer lugar, se estudia el control de la propagación de ondas en transmisión en sistemas conservativos. Específicamente, nuestro interés se centra en mostrar cómo los cristales sónicos son capaces de modificar la dispersión espacial de las ondas propagantes, dando lugar al control del ensanchamiento de haces de sonido. Haciendo uso de las curvas de dispersión espacial extraídas del análisis de la estructura de bandas, se predice primero la difracción nula y negativa de ondas a frecuencias cercanas al borde de la banda, resultando en la colimación y focalización de haces acústicos en el interior y detrás de un cristal sónico 3D, y posteriormente se demuestra mediante medidas experimentales. La eficiencia de focalización de un cristal sónico 3D está limitada debido a las múltiples reflexiones existentes en el interior del cristal. Para superar esta limitación se consideran estructuras axisimétricas trabajando en el régimen de longitud de onda larga, como lentes de gradiente de índice. En este régimen, las reflexiones internas se reducen fuertemente y, en configuración axisimétrica, la adaptación de simetría con fuentes acústicas radiando haces de sonido incrementa la eficiencia drásticamente. Además, la teoría de homogenización puede ser empleada para modelar la estructura como un medio efectivo con propiedades físicas efectivas, permitiendo el estudio del frente de ondas en términos refractivos. Se mostrará el modelado, diseño y caracterización de un dispositivo de focalización eficiente basado en los conceptos anteriores. Considérese ahora una estructura periódica en la que uno de los parámetros de la red, sea el paso de red o el factor de llenado, cambia gradualmente a lo largo de la dirección de propagación. Los cristales chirp representan este concepto y son empleados aquí para demostrar un mecanismo novedoso de incremento de la intensidad de la onda sonora basado en un fenómeno conocido como reflexión "suave". Este incremento está relacionado con una ralentización progresiva de la onda conforme se propaga a través del material, asociado con la velocidad de grupo de la relación de dispersión local en los planos del cristal. Un modelo basado en la teoría de modos acoplados es propuesto para predecir e interpretar este efecto. Se observan dos fenómenos diferentes al considerar pérdidas en estructuras periódicas. Por un lado, si se considera la propagación de ondas sonoras en un array periódico de capas absorbentes, cuyo frente de ondas es paralelo a los planos del cristal, se produce una reducción anómala en la absorción combinada con un incremento simultáneo de la reflexión y transmisión a las frecuencias de Bragg, de forma contraria a la habitual reducción de la transmisión, característica de sistemas periódicos conservativos a estas frecuencias. En el caso de la misma estructura laminada en la que se cubre uno de sus lados mediante un reflector rígido, la incidencia de ondas sonoras desde un medio homogéneo, cuyo frente de ondas es perpendicular a los planos del cristal, produce un gran incremento de la fuerza de
[CAT] Els cristalls fonònics són materials artificials formats per una disposició d'inclusions en un medi, ambdós poden ser sòlids o fluids. Controlant la geometría i el contrast d'impedàncies dels seus materials constituents, és poden controlar les propietats dispersives de les ondes, permetent una gran varietatde fenòmens fonamentals interessants en el context de la propagació d'ones. Quan una ona propagant troba un medi amb pèrdues amb propietats físiques diferents es pot transmetre i reflectir, però també absorbida si la dissipació es té en compte. Aquests fenòmens fonamentals s'han explicat clàssicament en el context de medis homogenis, però també ha sigut un tema de creixent interés en el context d'estructures periòdiques en els últims anys. Aquesta tesi doctoral tracta de l'estudi de diferents efectes en cristalls fonònics i sònics lligats a la transmissió, reflexió i absorció d'ones, així com del desenvolupament d'una tècnica de caracterització de les propietats dispersives, descrites mitjançant la estructura de bandes. En primer lloc, s'estudia el control de la propagació ondulatori en transmissió en sistemes conservatius. Més específicament, el nostre interés és mostrar com els cristalls sonors poden modificar la dispersió espacial d'ones propagants donant lloc al control de l'amplària per difracció dels feixos sonors. Mitjançant les corbes dispersió espacial obtingudes de l'anàlisi de l'estructura de bandes, es prediu, en primer lloc, la difracció d'ones zero i negativa a freqüències próximes al final de banda. El resultat és la collimació i focalització de feixos sonors dins i darrere de cristalls de so. Després es mostra amb mesures experimentals. L'eficiència de focalització d'un cristall de so 3D està limitada per la gran dispersió d'ones dins del cristall, que és característic del règim difractiu. Per a superar aquesta limitació, estructures axisimètriques que treballen en el règim de llargues longituds d'ona, i es comporten com a lents de gradient d'índex. En aquest règim, la dispersió es redueix enormement i, en una configuració axisimètrica, a causa de l'acoblament de la simetría amb les fonts acústiques que radien feixos sonors, l'eficiència de radiació s'incrementa significativament. D'altra banda, la teoria d'homogeneïtzació es pot utilitzar per a modelar, dissenyar i caracteritzar un dispositiu eficient de focalització basat en aquests conceptes. Considerem ara una estructura periòdica en la qual un dels seus paràmetres de xarxa, com ara la constant de xarxa o el factor d'ompliment canvia gradualment al llarg de la direcció de propagació. Els cristalls chirped representen aquest concepte i s'utilitzen ací per a demostrar un mecanisme nou d'intensificació d'ones sonores basat en el fenòmen conegut com a reflexió "suau". La intensificació està relacionada amb la alentiment progressiva de l'ona conforme propaga al llarg del material, que està associada amb la velocitat de grup de la relació de dispersió local en els diferents plànols del cristall. Es proposa un model basat en la teoria de modes acoblats per a predir i interpretar este efecte. Dos fenòmens diferents cal destacar quan es tracta d'estructures periòdiques amb dissipació. Per un costat, al considerar la propagació d'ones sonores en el plànol en un array periòdic de capes absorbents, s'observa una disminució anòmala de l'absorció i es combina amb un augment simultani de reflexió i transmissió en les freqüències de Bragg que contrasta amb la usual disminució de transmissió, característica dels sistemes conservatius a eixes freqüències. Per a un medi similar de capes, amb un reflector rígid darrere, les ones fora del pla incidint l'estructura des de un medi homogeni, augmentaran considerablement la interacció. En altres paraules, el retràs temporal de les ones sonores dins del sistema periòdic augmentarà significativament produint un augmen
Cebrecos Ruiz, A. (2015). Transmission, reflection and absorption in Sonic and Phononic Crystals [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/56463
TESIS
Premiado
Chen, Da. "Nouveaux modèles de chemins minimaux pour l'extraction de structures tubulaires et la segmentation d'images". Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLED037/document.
Texto completo da fonteIn the fields of medical imaging and computer vision, segmentation plays a crucial role with the goal of separating the interesting components from one image or a sequence of image frames. It bridges the gaps between the low-level image processing and high level clinical and computer vision applications. Among the existing segmentation methods, minimal geodesics have important theoretical and practical advantages such as the global minimum of the geodesic energy and the well-established fast marching method for numerical solution. In this thesis, we focus on the Eikonal partial differential equation based geodesic methods to investigate accurate, fast and robust tubular structure extraction and image segmentation methods, by developing various local geodesic metrics for types of clinical and segmentation tasks. This thesis aims to applying different geodesic metrics based on the Eikonal framework to solve different image segmentation problems especially for tubularity segmentation and region-based active contours models, by making use of more information from the image feature and prior clinical knowledges. The designed geodesic metrics basically take advantages of the geodesic orientation or anisotropy, the image feature consistency, the geodesic curvature and the geodesic asymmetry property to deal with various difficulties suffered by the classical minimal geodesic models and the active contours models. The main contributions of this thesis lie at the deep study of the various geodesic metrics and their applications in medical imaging and image segmentation. Experiments on medical images and nature images show the effectiveness of the presented contributions
Antoine, Pierre-Cornélius. "Etude des dalles sur sols renforcés au moyen d'inclusions rigides ou non". Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209997.
Texto completo da fonteDoctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Thomas, Antoine. "Problèmes de réarrangement avec marqueurs génomiques dupliqués". Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2014. http://tel.archives-ouvertes.fr/tel-01067114.
Texto completo da fonteHliwa, Mohamed. "Traitement simplifie des interactions moleculaires en chimie quantique". Toulouse 3, 1988. http://www.theses.fr/1988TOU30038.
Texto completo da fonteLi, Jhen-Hau, e 李振豪. "Production Structure of Seafood Industry and its Trading Blocs". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/91181326976801814463.
Texto completo da fonte國立臺灣海洋大學
應用經濟研究所
98
With the rapid growth of the global output of seafood products, the global seafood trade resulting increases every year, accompanied by a high degree of trade between countries correlation form trade blocks of seafood trade phenomenon. Firstly, through the annual seafood capture and aquaculture production and trade data of the production structure and long-term trade trends, indicating the development of Overview and Features seafood. Secondly, the use of cluster analysis showed the phenomenon of seafood trade block. Finally, gravity models used in the empirical analysis of trade of seafood products, verification of trade blocks, production and other relevant variables, and significant influence. Empirical results show that: (1) seafood products trade in 1970 that the formation of trade blocks and blocks of clear distinction between the Pacific Ocean and the European block after 1990. Over the years, the Pacific countries in trade flows within the block appear year by year growth trend, as the European growth rate of relatively small. (2) larger bilateral economic, trade flows higher; with population growth, producing countries will supply the domestic market as the first priority, allows reduction of trade flows; (3) The exporter of seafood produce higher yields, mean the export supply capacity is stronger, helps the growth of trade flows; (4) the greater the distance between the two countries trade, the trade cost of higher trade flows reduce.
Jaubert, Claire. "Synthèse et caractérisation de polymères biodégradables à partir d'acides biliaires à des fins biomédicales". Thèse, 2006. http://hdl.handle.net/1866/17966.
Texto completo da fonte