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See detailGénération de maillages éléments finis d’ordre élevé
Johnen, Amaury ULg

Master's dissertation (2010)

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See detailGénération de maillages pour la creation de modèles biomécaniques du cerveau
D'Otreppe, Vinciane ULg; Boman, Romain ULg; Ponthot, Jean-Philippe ULg

in Raous, Michel; Pasquet, Philippe; Rey, Christian (Eds.) Neuvième Colloque National en Calcul des Structures (2009, May)

Nous présentons une méthode efficace et automatique pour générer des maillages éléments finis surfaciques de haute qualité et de bonne fidélité géométrique au départ d’images médicales segmentées. Cette ... [more ▼]

Nous présentons une méthode efficace et automatique pour générer des maillages éléments finis surfaciques de haute qualité et de bonne fidélité géométrique au départ d’images médicales segmentées. Cette méthode est basée sur l’algorithme du Marching Tetrahedra auquel nous avons adjoint des techniques permettant d’ajuster la topologie et les positions nodales du maillage afin de renforcer la qualité des éléments tout en respectant la géométrie de l’objet présent dans les images. Le but ultime de l’approche est la modélisation du cerveau lors d’interventions neurochirurgicales. [less ▲]

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See detailGénération de maillages surfaciques pour la création de modèles biomécaniques du cerveau
D'Otreppe, Vinciane ULg

Master's dissertation (2008)

Le planning préopératoire en neurochirurgie est réalisé à partir d'images structurelles et fonctionnelles du patient. Cependant l'intervention chirurgicale réalisée à partir de ce planning se fonde sur l ... [more ▼]

Le planning préopératoire en neurochirurgie est réalisé à partir d'images structurelles et fonctionnelles du patient. Cependant l'intervention chirurgicale réalisée à partir de ce planning se fonde sur l'hypothèse que les structures anatomiques ne bougent pas pendant l'opération. En réalité, pendant l'opération, le cerveau se déforme de sorte que les images préopératoires, sur lesquelles se base le neurochirurgien, ne correspondent plus à la réalité anatomique du patient. Un approche envisagée pour résoudre ce problème est de modéliser, par la méthode des éléments finis, le comportement mécanique du cerveau pendant l'opération. Ceci permettrait de fournir au chirurgien, tout au long de l'intervention, des images mises à jour de la même qualité que les images préopératoires. La création du maillage du modèle biomécanique du cerveau à partir d'images IRM préopératoires fait l'objet de ce travail. La première et majeure partie du travail est consacrée à l'élaboration d'un mailleur surfacique. L'extraction de la surface, définie soit à l'aide d'une fonction implicite, soit à l'aide d'une image tridimensionnelle, se fait au moyen de la méthode Marching Tetrahedra. Le maillage ainsi obtenu étant inadapté au calcul éléments finis, il est ensuite simplifié et amélioré de manière à obtenir un maillage de bonne qualité. Afin de découpler la taille des mailles générées de la distance inter-slices, une méthode d'interpolation entre images a également été implémentée. La seconde partie est l'intégration du mailleur surfacique créé dans l'embryon du système de neuronavigation en cours de développement à l'ULg. Par simplicité, le cerveau est considéré comme un milieu homogène et seul le phénomène du brain shift est modélisé. De plus, les images IRM sont supposées avoir été préalablement corrigées, segmentées et recalées. Les résultats obtenus après calcul éléments finis similaires à ceux trouvés dans la littérature. [less ▲]

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See detailGénération décomplexée : Regard sur la bande dessinée alternative en Belgique francophone
Dejasse, Erwin ULg

in La Bande dessinée alternative (2012)

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See detailGénération et contrôle de validité de nombres pseudo-aléatoires sur un ordinateur à mots de 16 bits
Claustriaux, Jean-Jacques ULg

in Revue de Statistique Appliquée (1976), 24(2), 75-88

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See detailGénération et transfert des crues extrêmes : le modèle FAITOU
Dubois, Jérôme; Pirotton, Michel ULg; Schleiss, Anton

Book published by EPFL - Communications du Laboratoire de Constructions Hydrauliques - Ecole Polytechnique Fédérale de Lausanne (EPFL), Ed. A. Schleiss (2002)

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See detailGénération innommable
Demoulin, Laurent ULg

in Textyles : Revue des Lettres Belges de Langue Française (1997), 14

Evocation de tendances romanesque ayant émergé dans les années 1980 et 1990 envisagées au moyen des notions discutables et discutées de "minimalisme" et de "postmodernité".

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See detailGénération non-intentionnelle de polluants: Le cas des dioxines
Focant, Jean-François ULg

Article for general public (2003)

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See detailGeneration of a F.E.M mesh from stereolithography (STL) files
Béchet, Eric ULg; Cuillère, Jean-Christophe; Trochu, François

Scientific conference (2000)

The aim of the method proposed here is to show the possibility of generating adaptive surface meshes suitable for the finite element method, directly from an approximated boundary representation of an ... [more ▼]

The aim of the method proposed here is to show the possibility of generating adaptive surface meshes suitable for the finite element method, directly from an approximated boundary representation of an object coming from a Computer Aided Design software. First, we describe this boundary representation, then, we will show how to obtain a conforming, size adapted, mesh. This size adaptation is made with consideration to the geometrical approximation as well as to the respect of an isotropic or anisotropic map, coming from an error estimator. This mesh can be used “as is” for a finite element computation (with shells elements), or be used as to initiate a volume meshing algorithm (Delaunay or advancing front), for 3D simulation. Finally, we will show than the non use of the parametric representation of the geometrical model allows us to do override some limitations of the traditional meshing software based on an exact representation of the geometry. [less ▲]

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See detailGeneration of a finite element MESH from stereolithography (STL) files
Béchet, Eric ULg; Cuilliere, Jean-Christophe; Trochu, François

in Computer-Aided Design (2002), 34(1), 1-17

The aim of the method proposed here is to show the possibility of generating adaptive surface meshes suitable for the finite element method, directly from an approximated boundary representation of an ... [more ▼]

The aim of the method proposed here is to show the possibility of generating adaptive surface meshes suitable for the finite element method, directly from an approximated boundary representation of an object created with CAD software. First, we describe the boundary representation, which is composed of a simple triangulation of the surface of the object. Then we will show how to obtain a conforming size-adapted mesh. The size adaptation is made considering geometrical approximation and with respect to an isotropic size map provided by an error estimator. The mesh can be used "as is" for a finite element computation (with shell elements), or can be used as a surface mesh to initiate a volume meshing algorithm (Delaunay or advancing front). The principle used to generate the mesh is based on the Delaunay method, which is associated with refinement algorithms, and smoothing. Finally, we will show that not using the parametric representation of the geometrical model allows us to override some of the limitations of conventional meshing software that is based on an exact representation of the geometry. (C) 2001 Published by Elsevier Science Ltd. [less ▲]

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See detailGeneration of a soluble recombinant trimeric form of bovine CD40L and its potential use as a vaccine adjuvant in cows
Pujol, Julien ULg; Bouillenne, Fabrice ULg; Farnir, Frédéric ULg et al

in Veterinary immunology and immunopathology (2015), 168(1), 1-13

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See detailGeneration of a transposon insertion mutant library for bovine herpesvirus 4 cloned as a bacterial artificial chromosome by in vitro MuA based DNA transposition system.
Donofrio, Gaetano; Martignani, Eugenio; Sartori, Chiara et al

in Journal of Virological Methods (2007), 141(1), 63-70

Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus with no clear disease association. Although the BoHV-4 genome has been sequenced, the function of the majority of putative genes is elusive. Several ... [more ▼]

Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus with no clear disease association. Although the BoHV-4 genome has been sequenced, the function of the majority of putative genes is elusive. Several features make BoHV-4 attractive as a backbone for use as a viral expression vector and/or as a model to study gamma herpesvirus biology and determining which genes are essential for its replication is a very important task. Starting from BoHV-4 genome cloned as infectious bacterial artificial chromosome (BAC-BoHV-4) in Escherichia coli. A random insertion mutant library for BoHV4 was generated by the use of MuA transposase-catalyzed in vitro transposition reaction. Viral mutant transfection and direct sequencing allow the rapid determination of which BoHV-4 genes are essential for viral growth in a permissive eukaryotic cell line. BoHV-4 functional analysis information is fundamental when the BoHV-4 genome is modified for vector purposes. [less ▲]

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See detailGeneration of accurate finite element models of nonlinear systems - Application to an aeroplane-like structure
Kerschen, Gaëtan ULg; Golinval, Jean-Claude ULg

in Nonlinear Dynamics (2005), 39(1-2), 129-142

Model updating and validation is currently a central issue in the fields of computational structural mechanics and dynamics. The vast majority of applications however concerns linear structures. On the ... [more ▼]

Model updating and validation is currently a central issue in the fields of computational structural mechanics and dynamics. The vast majority of applications however concerns linear structures. On the other hand, updating nonlinear models is something the structural dynamicist prefers to avoid mainly because tools such as modal analysis are no longer available. The objective of the present study is to propose a two-step methodology for dealing with nonlinear systems. Its most appealing feature is that it decouples the estimation of the linear and nonlinear parameters. A numerical application consisting of an aeroplane-like structure is used to assess the efficiency of the procedure. [less ▲]

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See detailGeneration of all Symmetric and all Total Angular Momentum Eigenstates in Remote Qubits
Maser, A.; Schilling, U.; Bastin, Thierry ULg et al

Poster (2010)

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See detailGeneration of all symmetric as well as all total angular momentum eigenstates in photonic or matter qubits
von Zanthier, J.; Maser, A.; Wiegner, R. et al

Conference (2011)

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See detailGeneration of analysis and consistent error fields using the Data Interpolating Variational Analysis (Diva)
Troupin, Charles ULg; Barth, Alexander ULg; Sirjacobs, Damien ULg et al

in Ocean Modelling (2012), 52-53

The Data Interpolating Variational Analysis (Diva) is a method designed to interpolate irregularly-spaced, noisy data onto any desired location, in most cases on regular grids. It is the combination of a ... [more ▼]

The Data Interpolating Variational Analysis (Diva) is a method designed to interpolate irregularly-spaced, noisy data onto any desired location, in most cases on regular grids. It is the combination of a particular methodology, based on the minimisation of a cost function, and a numerically efficient method, based on a finite-element solver. The cost function penalises the misfit between the observations and the reconstructed field, as well as the regularity or smoothness of the field. The intrinsic advantages of the method are its natural way to take into account topographic and dynamic constraints (coasts, advection, . . . ) and its capacity to handle large data sets, frequently encountered in oceanography. The method provides gridded fields in two dimensions, usually in horizontal layers. Three-dimension fields are obtained by stacking horizontal layers. In the present work, we summarize the background of the method and describe the possible methods to compute the error field associated to the analysis. In particular, we present new developments leading to a more consistent error estimation, by determining numerically the real covariance function in Diva, which is never formulated explicitly, contrarily to Optimal Interpolation. The real covariance function is obtained by two concurrent executions of Diva, the first providing the covariance for the second. With this improvement, the error field is now perfectly consistent with the inherent background covariance in all cases. A two-dimension application using salinity measurements in the Mediterranean Sea is presented. Applied on these measurements, Optimal Interpolation and Diva provided very similar gridded fields (correlation: 98.6%, RMS of the difference: 0.02). The method using the real covariance produces an error field similar to the one of OI, except in the coastal areas. [less ▲]

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See detailGeneration of arbitrary Dicke states in remote qubits using linear optics
Maser, A.; Thiel, C.; Schilling, U. et al

Conference (2008)

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