Search results for "Modèle"
showing 10 items of 311 documents
Modeling by the finite element method of acoustic radiation in waveguides lined with locally or non locally reacting absorbent materials in the prese…
2011
Our concern in this work is the problem of acoustic propagation in guides lined with locally or non locally reacting materials with the presence of mean fluid flow. In several industrial systems such as aircraft jet engines, mufflers exhaust and ventilation systems, noise is mostly channeled outside by guides of more or less complex geometries. A study of waveguides makes it possible to predict and understand the physical phenomena such as refraction, convection, absorption and wave attenuation. In waveguides studies, guides are often considered infinitely long to get rid of some phenomena (reflection for example) at their ends. Solving the problem of acoustic propagation in infinite guides…
Study of TiO2 nanostructures grown in a MOCVD reactor in presence of metallic catalysts. Valorization of these TiO2 nanostructures
2017
Within the Nanoform Theme, Ax Nanosciences, ICB, we realize the growth of 1D, 2D and 3D hybrid nanostructures based on TiO2 by MOCVD. Our work deals with the theoretical aspect of the formation of these nanostructures (growth and kinetic models, structure and texture) and the study of photoelectric, optical and physicochemical properties as well as the development of applications of these structures in physics (random laser), photocatalysis, energy (solar cells). Under certain perfectly controlled conditions, we obtain original TiO2 structures not yet described in the literature: membranes, rods , canals, crucibles, COHN (COaxiales Heterostructures Nanowires). Our previous work made it poss…
PESACA : Post-édition semi-automatique à partir d’un corpus agroalimentaire
2022
Le projet PESACA vise, à travers l’entraînement d’un modèle de post-édition, à améliorer la qualité des sorties de systèmes de traduction automatique neuronale en français langue de spécialité, en prenant comme cas d’usage pilote le domaine agroalimentaire. Il s’inscrit dans la circulation des savoirs et des idées spécialisés puisque le modèle visé enrichira les processus et les mécanismes de transfert linguistique, en intégrant des données linguistiques issues de discours spécialisés rédigés en langue naturelle française
Trois algorithmes intelligents pour la numérisation 3D automatique d'objets inconnus
2013
National audience; Ce papier propose trois approches itératives et intelligentes de planification de vue pour la numérisation 3D d'objets sans connaissance a priori de leurs formes. La première méthode est une approche simple et naïve basée sur la génération d'un ensemble de points de vues par échantillonnage régulier de l'enveloppe englobante des données acquises. La deuxième méthode est basée sur une analyse de l'orientation des différentes parties acquises. La troisième méthode vise à explorer les parties de l'objet qui figurent dans la limite du champ de visibilité et est basée sur un couplage de la visibilité angulaire avec la visibilité réelle par lancer de rayons. Les résultats de nu…
Retrievals of soil moisture and optical depth from CAROLS
2011
International audience; We propose in this paper to evaluate a method to retrieve soil moisture (SM) and vegetation optical thickness, in areas of unknown roughness and unknown vegetation water content in view of operational applications, by using airborne Tb measurements acquired in South-West of France. Results are compared to in situ measurements, manual and automatic ones included in SMOSmania network, in the South-West of France.
Etude des effets collisionnels dans les molécules tétraédriques. Applications au méthane perturbé par l'argon
1996
This thesis is devoted to the study of relaxational and collisional line-broadening processes in the first vibrational polyads of tetrahedral molecules. In a first part, the particular internal dynamics of such molecules is discussed. The second chapter reviews the literature on phenomena induced by intermolecular interactions involving this type of molecules. More theoretical aspects are developed in the second part. The so-called tetrahedral tensorial formalism adapted to the construction of Hamiltonians and transition moments of tetrahedral molecules is described. Main features of the infrared line-shapes theories and of semi-classical line-broadening and line-shifting calculations are a…
Un réexamen du modèle de gains de Mincer
1986
A re-appraisal of mincer's earnings model Starting from rough measures of formal schooling and on the job training, the earning model proposed by J. Mincer (1974) suceed to explain a substantial proportion of the variance of individual earning. The explanatory power of the model can be significantly boosted by increasing the quality of the variables. In spite of the robustness of the model, the interpretation of the results is to be taken cautiously. These results can be derived from alternative theoretical hypothesis and namely to the one known as the filter hypothesis. It is shown that a specification of the earnings function consistent with the filter hypothesis is proced to be empirical…
Un modèle développemental des capacités d’élaboration: la redescription des représentations
2021
International audience
Distribution models and environmental changes : Application to echinoid faunas in the Southern Ocean and ecoregionalization
2018
Current environmental changes, which impact marine environments, cover major scientific and societal issues, especially as these environmental changes are expected to accelerate along the 21st century. Understanding and forecasting the response of marine biodiversity to these changes is a pregnant scientific issue. Biogeographic and macroecological approaches provide a scientific framework for that purpose. They allow describing and understanding species distribution patterns at large spatial scale as well as estimating their potential shift with regards to environmental change. This is particularly true in the Southern Ocean, where the effects of climate change are already occurring and wh…
Inférence de la résistance du paysage au flux de gènes à l'aide de modèles gravitaires intégrant des variables intra-populationnelles
2021
International audience; Modéliser les mouvements de dispersion nécessite d'associer aux éléments paysagers des valeurs de coût caractérisant leur résistance aux déplacements. En landscape genetics, l'inférence de ces valeurs se fait à partir de mesures de différenciation génétique entre populations. Bien que l'hétérogénéité spatiale des tailles de populations puisse aussi influencer de façon significative la différenciation génétique, les variables intra-populationnelles sont rarement prises en compte dans ce type d'inférence. Nous avons étudié à quel point la prise en compte de ces variables pouvait améliorer l'inférence des coûts. Pour cela, nous avons simulé des flux de gènes entre 60 po…