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Artykuły w czasopismach na temat "Reconstructions 2D et 3D"
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Ferretti, G. R., i A. Jankowski. "Tomodensitométrie volumique : reconstructions 2D et 3D". Revue des Maladies Respiratoires 27, nr 10 (grudzień 2010): 1267–74. http://dx.doi.org/10.1016/j.rmr.2010.10.009.
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Powell, Leila C., Scott T. Kay, Arif Babul i Andisheh Mahdavi. "Investigating the Relationship Between the Hot Gas and the Dark Matter Components of Galaxy Clusters." Proceedings of the International Astronomical Union 3, S244 (czerwiec 2007): 374–75. http://dx.doi.org/10.1017/s1743921307014342.
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AbstractVarious differences in galaxy cluster properties derived from X-ray and weak lensing observations have been highlighted in the literature. One such difference is the observation of mass concentrations in lensing maps which have no X-ray counterparts (e.g. Jee, White, Ford et al. 2005). We investigate this issue by identifying substructures in maps of projected total mass (analogous to weak lensing mass reconstructions) and maps of projected X-ray surface brightness for three simulated clusters. We then compare the 2D mass substructures with both 3D subhalo data and the 2D X-ray substructures. Here we present preliminary results from the first comparison, where we have assessed the impact of projecting the data on subhalo identification.
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Tang, Jinghua, Dianne W. Taylor i Kenneth A. Taylor. "Cryo-EM 3D Reconstruction of Skeletal Muscle α-Actinin". Microscopy and Microanalysis 6, S2 (sierpień 2000): 248–49. http://dx.doi.org/10.1017/s1431927600033730.
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α-Actinin is a member of the spectrin superfamily of actin crosslinking proteins. The molecule is an antiparallel homodimer with a polypeptide chain weight of 94-103 kDa. Each chain can be divided into three domains: the N-terminal 250 amino acids forms an actin binding domain, the central domain consisting of four spectrin-like, triple-helical repeats and the Cterminal which contains two EF hand motifs (Baron et al, 1987).Two models have been proposed for the alignment of the triple helical repeats in the α-actinin structure, an aligned model (Baron et al., 1987) and a staggered model (Taylor and Taylor, 1993). In order to resolve the controversy, we proceeded with the cryo-EM 3D reconstruction from 2D crystal grown on a positively charged lipid monolayer. From rabbit erector spinae aactinin, we obtain better ordered 2D crystals from which we have calculated a 3D reconstruction to ∼15 Å resolution.
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Narasimhadhan, A. V., i Kasi Rajgopal. "FDK-Type Algorithms with No Backprojection Weight for Circular and Helical Scan CT". International Journal of Biomedical Imaging 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/969432.
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We develop two Feldkamp-type reconstruction algorithms with no backprojection weight for circular and helical trajectory with planar detector geometry. Advances in solid-state electronic detector technologies lend importance to CT systems with the equispaced linear array, the planar (flat panel) detectors, and the corresponding algorithms. We derive two exact Hilbert filtered backprojection (FBP) reconstruction algorithms with no backprojection weight for 2D fan-beam equispace linear array detector geometry (complement of the equi-angular curved array detector). Based on these algorithms, the Feldkamp-type algorithms with no backprojection weight for 3D reconstruction are developed using the standard heuristic extension of the divergent beam FBP algorithm. The simulation results show that the axial intensity drop in the reconstructed image using the FDK algorithms with no backprojection weight with circular trajectory is similar to that obtained by using Hu's and T-FDK, algorithms. Further, we present efficient algorithms to reduce the axial intensity drop encountered in the standard FDK reconstructions in circular cone-beam CT. The proposed algorithms consist of mainly two steps: reconstruction of the object using FDK algorithm with no backprojection weight and estimation of the missing term. The efficient algorithms are compared with the FDK algorithm, Hu's algorithm, T-FDK, and Zhu et al.'s algorithm in terms of axial intensity drop and noise. Simulation shows that the efficient algorithms give similar performance in axial intensity drop as that of Zhu et al.'s algorithm while one of the efficient algorithms outperforms Zhu et al.'s algorithm in terms of computational complexity.
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Orthuber, E., i J. Avbelj. "3D BUILDING RECONSTRUCTION FROM LIDAR POINT CLOUDS BY ADAPTIVE DUAL CONTOURING". ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences II-3/W4 (11.03.2015): 157–64. http://dx.doi.org/10.5194/isprsannals-ii-3-w4-157-2015.
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This paper presents a novel workflow for data-driven building reconstruction from Light Detection and Ranging (LiDAR) point clouds. The method comprises building extraction, a detailed roof segmentation using region growing with adaptive thresholds, segment boundary creation, and a structural 3D building reconstruction approach using adaptive 2.5D Dual Contouring. First, a 2D-grid is overlain on the segmented point cloud. Second, in each grid cell 3D vertices of the building model are estimated from the corresponding LiDAR points. Then, the number of 3D vertices is reduced in a quad-tree collapsing procedure, and the remaining vertices are connected according to their adjacency in the grid. Roof segments are represented by a Triangular Irregular Network (TIN) and are connected to each other by common vertices or - at height discrepancies - by vertical walls. Resulting 3D building models show a very high accuracy and level of detail, including roof superstructures such as dormers. The workflow is tested and evaluated for two data sets, using the evaluation method and test data of the “ISPRS Test Project on Urban Classification and 3D Building Reconstruction” (Rottensteiner et al., 2012). Results show that the proposed method is comparable with the state of the art approaches, and outperforms them regarding undersegmentation and completeness of the scene reconstruction.
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Saidi, Mohamed. "L’intérêt de la segmentation en 2D et la reconstruction en 3D d’un processus tumoral de la hanche". Morphologie 100, nr 330 (wrzesień 2016): 151. http://dx.doi.org/10.1016/j.morpho.2016.07.157.
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Baba, Assia, i Mohamed Saidi. "L’intérêt de la segmentation en 2D et la reconstruction en 3D dans les différentes pathologies médico-chirurgicales". Morphologie 102, nr 338 (wrzesień 2018): 163. http://dx.doi.org/10.1016/j.morpho.2018.07.061.
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Sorzano, C. O. S., J. Vargas, J. Otón, J. M. de la Rosa-Trevín, J. L. Vilas, M. Kazemi, R. Melero i in. "A Survey of the Use of Iterative Reconstruction Algorithms in Electron Microscopy". BioMed Research International 2017 (2017): 1–17. http://dx.doi.org/10.1155/2017/6482567.
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One of the key steps in Electron Microscopy is the tomographic reconstruction of a three-dimensional (3D) map of the specimen being studied from a set of two-dimensional (2D) projections acquired at the microscope. This tomographic reconstruction may be performed with different reconstruction algorithms that can be grouped into several large families: direct Fourier inversion methods, back-projection methods, Radon methods, or iterative algorithms. In this review, we focus on the latter family of algorithms, explaining the mathematical rationale behind the different algorithms in this family as they have been introduced in the field of Electron Microscopy. We cover their use in Single Particle Analysis (SPA) as well as in Electron Tomography (ET).
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Naldi, Giovanni, Barbara Avuzzi, Simona Fantini, Mauro Carrara, Ester Orlandi, Elisa Massafra i Stefano Tomatis. "A SEGMENTATION PROBLEM IN QUANTITATIVE ASSESSMENT OF ORGAN DISPOSITION IN RADIOTHERAPY". Image Analysis & Stereology 30, nr 3 (1.11.2011): 179. http://dx.doi.org/10.5566/ias.v30.p179-186.
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Radiotherapeutic treatment of cancer is best conducted if the prescription dose is given to the tumor while surrounding normal tissues are maximally spared. With the aim to meet these requirements the complexity of radiotherapy techniques have steadily increased under a strong technological impulse, especially in the last decades. One problem involves the rate of the particular disposition of the structures of interest in a patient. Recently the authors (Tomatis et al., 2010; 2011) have proposed a computational approach in order to represent quantitatively the geometrical features of organs at risk, summarized in characteristics of distance, shape and orientation of such organs in respect to the target. A basic problem to solve before to compute the risk index, is the segmentation of the organs involved in the radiotherapy planning. Here we described a 3D segmentation method by using the clinical computed tomography (CT) data of the patients. Our algorithm is based on different steps, a preprocessing phase where a nonlinear diffusion filter is applied; a level set based method for extract 2D countours; a postprocessing reconstruction of 3D volume from 2D segmented slices. Some comparisons with manually traced segmentation by clinical experts are provided.
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Jovicevic, Jovan, i Alan Bewick. "A study of the initial stages of the electrochemical deposition of metals on foreign substrates: Lead and thallium on copper and silver surfaces: General discussion". Facta universitatis - series: Physics, Chemistry and Technology 3, nr 2 (2005): 183–203. http://dx.doi.org/10.2298/fupct0502183j.
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The basic applicability of the UPD theory of Gerischer et al. has been confirmed in the case of lead and thallium deposition on copper and silver single crystals, but it was shown also that this is only one of the important factors. It was established that the effect of substrate structure on the mechanism of the UPD monolayer formation plays an important role in the addition to the effect of electronegativity difference between the substrate and depositing atoms. An effect of changing the concentration of depositing metal and specifically adsorbing anion were found and attributed to the changes in the electronegativity of the substrate and underpotential layer as a result of changing the electrode potential. It was conclusively proven by the analysis of the peaked current-time transients obtained by potential step measurements and the very sharp voltammetry peaks, that first order 2D phase transformations are possible in UPD systems. It was also found that the L.S.V. peaks reflecting such processes must not be expected to be free from the influence of slow kinetics. It was established that the 2D crystalline metal-like phases with the closest-packed epitaxial structure exist as a stable, final product in UPD. Moreover, the possibility of higher order 2D transformations in UPD has been given strong support by the evidence of gradual monolayer density change with increasing driving force. Lead UPD on vitreous carbon was found to be the result of substrate reconstruction induced by the repeated deposition and dissolution leading to surface condition changes favoring deposition of the first layer. UPD monolayers on copper and silver surfaces always preceded OPD and had a profound effect on its nucleation overpotential (making it very small indeed) or even changing its character from 3D into 2D (in the case of vitreous carbon substrate). It was also shown that lead and thallium OPD on copper and silver single crystals starts off by charge transfer controlled instantaneous 3D nucleation and subsequent growth of 3D centers. Finally, the results obtained in the experiments performed have shown that electrochemical techniques can prove very suitable in the study of 2D phase transformation kinetics and that their further employment in this field should prove particularly rewarding.
Rozprawy doktorskie na temat "Reconstructions 2D et 3D"
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Rolland, Franck Montanvert Annick. "Représentation tridimensionnelle et reconstruction 3D à partir de coupes 2D". S.l. : Université Grenoble 1, 2008. http://tel.archives-ouvertes.fr/tel-00339648.
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Rolland, Franck. "Représentation tridimensionnelle et reconstruction 3D à partir de coupes 2D". Phd thesis, Grenoble 1, 1991. http://tel.archives-ouvertes.fr/tel-00339648.
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L'objectif des travaux présentés dans ce mémoire est la représentation de formes tridimensionnelles ainsi que la reconstruction tridimensionnelle a partir de coupes sériées. Après avoir défini le cadre exact de la reconstruction tridimensionnelle a partir de coupes sériées, le premier chapitre analyse les différentes étapes et les méthodes généralement employées pour effectuer cette reconstruction. Les chapitre 2 et 3 s'attachent a la description et a la représentation de formes tant bidimensionnelles que tridimensionnelles. Le chapitre 3 developpe ainsi une methode de squelettisation tridimensionnelle permettant d'obtenir un squelette filaire. Le chapitre 4 est consacre a la description de deux méthodes de reconstruction tridimensionnelle opérant par inférence de formes. La methode utilisant l'inférence structurelle de graphes de la ligne médiane est ensuite développée. Elle passe par une nécessaire étape, chapitre 5, de mise en correspondance de graphes de la ligne médiane. Différentes méthodes de mise en correspondance sont présentées, finalement la methode procédant par recherche de cliques dans un graphe est développée. La construction du graphe de mise en correspondance est tout d'abord présentée, ensuite la recherche de cliques est abordée a l'aide de méthodes heuristiques de parcours (recuit simule et algorithmes génétiques). Le chapitre 6 développe le processus d'inférence de graphes de la ligne médiane mis en œuvre, il permet d'inférer des coupes intermediaires qui sont empilées pour finalement donner le volume tridimensionnel recherche. Le chapitre 7 est consacre a la présentation des divers résultats et de leurs conséquences, il présenté aussi d'autres applications possibles des différentes techniques developpees
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MIGEON, BRUNO. "Reconstruction 2d et 3d d'os longs des membres par traitement d'images echographiques". Orléans, 1993. http://www.theses.fr/1993ORLE2025.
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L'objet de cette these est la reconstruction 3d des os longs des membres a partir de coupes paralleles successives reconstruites par tomographie ultrasonore. L'originalite du travail au niveau de la reconstruction 2d reside dans le developpement de methodes de tomographie ultrasonore en mode reflexion par traitement d'images radiales (acquises avec des sondes echographiques classiques). Pour cela un systeme d'acquisition permettant d'obtenir plusieurs images radiales par plan de coupe et pour plusieurs plans de coupes paralleles successifs a ete realise. Le traitement des images permet la segmentation des structures recherchees et l'extraction de leurs contours, moyennant la resolution d'un certain nombre de problemes et de cas particuliers. La reconstruction 3d consiste a donner un sens a la scene volumique obtenue en etablissant des liens de connexion entre les differents contours extraits, afin de comprendre la scene comme un ensemble d'objets distincts. Il est ensuite possible de faire une representation 3d par facettes planes via une etape de triangulation, et meme par listes de voxels grace a une methode originale d'interpolation de contours. La visualisation 3d permet ensuite de representer les structures sous n'importe quel angle de vue par des techniques classiques, avec rendu realiste grace a l'utilisation d'un modele d'ombrage
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Triki-Bchir, Olfa. "Modélisation, reconstruction et animation de personnages virtuels 3D à partir de dessins manuels 2D". Phd thesis, Université René Descartes - Paris V, 2005. http://tel.archives-ouvertes.fr/tel-00273248.
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La production de dessins animés 2D, qui suit actuellement un schéma mis en place dans les années 1920, fait intervenir un très nombre de compétences humaines et de métiers différents. Par opposition à ce mode de travail traditionnel, la production de films de synthèse 3D, en exploitant les technologies et outils les plus récents de modélisation et d'animation 3D, s'affranchit pour une bonne part de cette composante artisanale et vient concurrencer l'industrie du dessin animé tradtionnel en termes de délais et de coûts de fabrication.Les défis à relever par l'industrie du dessin animé 2D se formulent donc en termes de:
1. Réutilisation des contenus selon le paradigme Create once, render many,
2. Facilité d'échange et de transmission des contenus, ce qui nécessite de disposer d'un unique format de représentation,
3. Production efficace et économique des contenus, requérant une animation automatisée par ordinateur.
Dans ce contexte compétitif, ce travail de thèse, réalisé dans le cadre du projet industriel TOON financé par la société Quadraxis avec le support de l' Agence Nationale de Valorisation de la Recherche (Oséo-ANVAR), a pour objectif de contribuer au développement d'une plate-forme de reconstruction, déformation et animation de modèles 3D pour les dessins animés 2D.
Un état de l'art des méthodes et outils contribuant à la reconstruction de modèles 3D et à leur animation est présenté et discuté au regard des contraintes spécifiques des règles de création des dessins animés 2D et de la chaîne de fabrication traditionnelle. Ayant identifié les verrous technologiques à lever, nos contributions ont porté sur :
* l'élaboration d'une méthode de reconstruction de personnages virtuels 3D à partir de dessins 2D,
* la mise au point d'une procédure de reconstruction surfacique par NURBS dotée d'une capacité de déformation interactive 2D/3D,
* la conception d'un module de modélisation 3D pour surfaces maillées, compatible avec le standard d'animation MPEG-4/AFX.
Les développements réalisés, intégrés dans un prototype de la plate-forme TOON, montrent un gain en temps de 20% sur l'ensemble de la chaîne de production tout en garantissant une complète interopérabilité des applications via le standard MPEG-4.
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Horna, Sébastien. "Reconstruction géométrique et topologique de complexes architecturaux 3D à partir de plans numériques 2D". Poitiers, 2008. http://theses.edel.univ-poitiers.fr/theses/2008/Horna-Sebastien/2008-Horna-Sebastien-These.pdf.
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L’intérieur des bâtiments est souvent modélisé en 3D pour diverses applications de modélisation ou de simulation. Par exemple, plusieurs méthodes permettent d’étudier l’éclairage, les transferts de chaleur, la propagation d’ondes. Ces applications nécessitent dans la plupart des cas une représentation volumique de l’environnement avec des relations d’adjacence et d’incidence entre les éléments. Malheureusement, les données correspondant au bâtiment sont en général seulement disponibles en 2D et les besoins des applications 3D varient d’une utilisation à l’autre. Pour résoudre ce problème, nous proposons une description formelle d’un ensemble de contraintes de cohérence dédiées à la modélisation d’intérieur de bâtiments. Dans cette thèse nous montrons comment cette représentation est utilisée pour : (i) reconstruire un modèle 3D à partir de plans d’architecte numériques 2D ; (ii) détecter automatiquement les incohérences géométriques, topologiques et sémantiques ; (iii) développer des opérations automatiques et semi-automatiques pour corriger les plans 2D. Toutes les contraintes de cohérence sont définies en 2D et 3D et reposent sur le modèle topologique des cartes généralisées. Ces opérations sont utilisées pour éditer les scènes 2D et 3D afin d’affiner ou de modifier les modèles. Enfin, nous expliquons comment ce modèle est utilisé pour une application de visualisation par lancé de rayonsVirtual architectural (indoor) scenes are often modelled in 3D for various types of simulation systems. For instance, some authors propose methods dedicated to lighting, heat transfer, acoustic or radio wave propagation simulations. These methods rely in most cases on a volumetric representation of the environment, with adjacency and incidence relationships. Unfortunately, many buildings data are only given by 2D plans and the 3D needs varies from one application to another. To solve these problems, we propose a formal representation of consistency constraints dedicated to building interiors and associated with a topological model. We show that such a representation can be used for : (i) reconstructing a 3D model from 2D architectural plans ; (ii) detecting automatically geometrical, topological and semantical inconsistencies ; (iii) designing automatic and semi-automatic operations to correct and enrich a 2D plan. All our constraints are homogeneously defined in 2D and 3D, implemented with generalized maps and used in modeling operations. We explain how this model can be successfully used with various ray-tracing methods
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Triki, Bchir Olfa. "Modélisation, reconstruction et animation de personnages virtuels 3D à partir de dessins manuels 2D". Paris 5, 2005. http://www.theses.fr/2005PA05S015.
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La production de dessins animés 2D qui suit actuellement un schéma mis en place dans les années 1920 fait intervenir un très grand nombre de compétences humaines. Par opposition à ce mode de travail traditionnel, la production de films 3D, en exploitant les technologies et outils les plus récents de modélisation et d'animation 3D, s'affranchit en bonne partie de cette composante artisanale et vient concurrencer l'industrie du dessin animé 2D en termes de temps et coûts de fabrication. Les enjeux à relever par l'industrie du dessin animé 2D se posent donc en termes de : 1. Réutilisation des contenus selon le célèbre paradigme du “Create once, render many”, 2. Facilité d'échange et transmission des contenus ce qui nécessite de disposer d'un unique format de représentation, 3. Production efficace et économique des contenus requérant alors une animation automatisée par ordinateur. Dans ce contexte compétitif, cette thèse, réalisée dans le cadre du projet industriel TOON financé par la société Quadraxis avec le support de l'Agence Nationale pour la Valorisation de la Recherche (ANVAR), a pour objectif de contribuer au développement d'une plate-forme de reconstruction, déformation et animation de modèles 3D pour les dessins animés 2D. Un état de l'art des méthodes et outils contribuant à la reconstruction de modèles 3D et à leur animation est présenté et discuté au regard des contraintes spécifiques des règles de création des dessins animés 2D et de la chaîne de fabrication 2D. Ayant identifié les verrous technologiques à lever, nos contributions ont porté sur : – L'élaboration d'une de reconstruction des personnages virtuels 3D àpartir de dessins 2D, – La mise au point d'une méthode de modélisation 3D par surfaces maillées, compatible avec le standard MPEG-4/AFX, Les développements réalisés, intégrés dans un premier prototype de la plate-forme TOON, montrent un gain en temps de 20% dans la chaîne de production et une complète interopérabilité des applications via le standard MPEG-4.
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Rekik, Wafa. "Fusion de données temporelles, ou 2D+t, et spatiales, ou 3D, pour la reconstruction de scènes 3D+t et traitement d'images sphériques : applications à la biologie cellulaire". Paris 6, 2007. http://www.theses.fr/2007PA066655.
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Dans certaines applications en vision, nous disposons de données volumiques (3D) et des séquences planaires (2D+t). Les données 3D définissent la géométrie en trois dimensions de la scène observée. Elles comportent donc des informations purement spatiales. Les séquences 2D+t sont porteuses d'informations temporelles et partiellement spatiales puisqu'elles décrivent en deux dimensions la dynamique des objets en mouvement. La fusion de ces données permet de restituer une séquence volumique (3D+t) de la scène filmée. Ces travaux s'articulent en deux volets. Le premier volet concerne une étude méthodologique de la reconstruction 3D+t par compensation du mouvent. Nous proposons deux familles d'approches : avec ou sans modèle a priori sur les structures observées dans les données. Le modèle a priori étudiée concernent des objets de géométrie sphérique. Le second volet décrit le traitement d'image multi-dimensionnels (2D, 3D, 2D+t, 3D+t) toujours dans le contexte de forme sphérique. Nous proposons alors diverses applications comme le suivi temporel sur les séquences 2D+t, la visualisation, la segmentation des données 2D ou 3D,. . . Une application possible est donnée en imagerie biologique dans le cadre de la simulation de parois cellulaires, contexte dans lequel nous observons dans diverses modalités des objets sphéroïdes.
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Lopez-Hernandez, Juan. "Imagerie Cardiaque Multimodalités 2D et 3D :application à la Coronarographie/Tomoscintigraphie/TEP-CT". Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2006. http://tel.archives-ouvertes.fr/tel-00118991.
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La coronarographie et la tomoscintigraphie (SPECT, de l'anglais "Single Photon Emission ComputedTomography") sont deux techniques d'imagerie utilisées couramment pour diagnostiquer les maladies
cardiovasculaires. La première modalité est constituée de séquences d'images à rayon X visualisant chacune,
dans un même plan, les artères coronaires situées sur la face avant et la face arrière du coeur. Les images à
rayons X fournissent des informations anatomiques liées à l'arbre artériel et mettent en évidence d'éventuels
rétrécissements des artères (sténoses). La modalité SPECT (imagerie nucléaire) fournit une représentation 3D
de la perfusion du volume myocardique. Cette information fonctionnelle permet la visualisation de régions
myocardiques souffrant de défauts d'irrigations. Le but du travail présenté est de superposer, en 3D, les
informations fonctionnelles et anatomiques pour établir un lien visuel entre des lésions artérielles et leurs
conséquences en termes de défauts d'irrigation. Dans la représentation 3D choisie pour faciliter le diagnostic, la
structure d'un arbre artériel schématique, comprenant les sténoses, est placée sur le volume de perfusion. Les
données initiales sont constituées d'une liste de points représentatifs de l'arbre artériel (points d'arrivée et de
départs de segments d'artères, bifurcations, sténoses, etc.) marqués par le coronarographiste dans les images à
rayons X des différentes incidences. Le volume de perfusion est ensuite projeté sous les incidences des images
de coronarographie. Un algorithme de recalage superposant les images à rayons X et les projections SPECT
correspondantes fournit les paramètres des transformations géométriques ramenant les points marqués dans les
images à rayons X dans une position équivalente dans les images SPECT. Un algorithme de reconstruction 3D
permet ensuite de placer les points artériels et les sténoses sur le volume de perfusion et de former un arbre
schématique servant de repère au clinicien. Une base de données formée de 28 patients a été utilisée pour
effectuer 40 superpositions 3D de données anatomo-fonctionnelles. Ces reconstructions ont montré que la
représentation 3D est suffisamment précise pour permettre d'établir visuellement un lien entre sténoses et
défauts de perfusions. Nos algorithmes de superpositions 3D ont ensuite été complétés pour remplacer la
modalité SPECT par les données de l'examen bimodal TEP/CT (Tomographie par Emission de
Positons/Tomodensitométrie). Les données d'un cas clinique trimodal TEP/CT/coronarographie ont été utilisées
pour vérifier l'adéquation de nos algorithmes à la nouvelle modalité d'imagerie.
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Garnero, Line. "Reconstruction d'images tomographiques à partir d'un ensemble limite de projections". Paris 11, 1987. http://www.theses.fr/1987PA112012.
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Nous proposons dans cette thèse deux méthodes de reconstitution d'images tomographiques à partir d'un nombre limité de projections couvrant un angle de vue limité. Ces circonstances se rencontrent aussi bien en Imagerie Médicale, que dans d'autres domaines comme la microscopie électronique. Ces méthodes utilisent des informations a priori sur l'objet afin de retrouver les données manquantes. Nous avons appliqué une de ces méthodes aussi bien à reconstructions bidimensionnelles, que directement tridimensionnelles, et nous l'avons aussi utilisée dans deux cas concrets relevant du domaine des contrôles non destructifs et de la microimagerie plasma laser. Nous présentons aussi une étude des artéfacts paraissant sur les images tomographiques de Médecine Nucléaire à la suite de mauvaises conditions d'acquisition.
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Merabet, Lucas. "Etude d’algorithmes de reconstruction ultrasonore dans le domaine de Fourier pour l’imagerie rapide 2D et 3D en contrôle non- destructif". Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLET060.
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Ce travail de thèse s’intéresse à l’imagerie ultrasonore multi-éléments pour le Contrôle Non-Destructif (CND), et vise à accélérer l’imagerie échographique en 2D et 3D. Les méthodes étudiées s’inspirent des algorithmes de reconstruction dans le domaine de Fourier (f-k) en imagerie sismique. La littérature montre que ces méthodes offrent un avantage numérique par rapport à celles dans le domaine temporel basées sur un principe de focalisation en émission/réception. D’autre part, l’essor des traducteurs multi-éléments a permis d’explorer de nouveaux modes d’émission, comme les ondes planes en imagerie médicale ultra-rapide. Dans cette thèse, on se propose de combiner les algorithmes rapides du domaine f-k avec des émissions planes pour calculer des images aussi rapidement que possible. Ces algorithmes sont adaptés pour traiter des configurations d’inspection usuelles en CND. Une analyse des complexités algorithmiques, des temps de calcul et de la qualité des reconstructions est menée en 2D. La comparaison avec la méthode temporelle Plane Wave Imaging (PWI) démontre un avantage certain pour l’imagerie f-k. Ces avantages sont confirmés en 3D où l’on démontre que cette dernière améliore la qualité d’image tout en réduisant le temps de calcul d’un facteur allant jusqu’à 300 par rapport à PWI. Enfin, la méthode f-k est généralisée à l’imagerie multimodale pour la caractérisation de fissures. La théorie est d’abord présentée, puis on montre qu’il est possible d’améliorer la qualité des reconstructions grâce à un fenêtrage des fréquences spatiales de l’image. Ce filtre spectral élimine des artéfacts d’imagerie liés à des échos de géométrie, améliorant ainsi le contraste des imagesThis research work deals with ultrasound imaging with transducer arrays for Non Destructive Testing (NDT), and aims at speeding up the formation of 2D and 3D images. The methods studied in this manuscript are inspired from reconstruction algorithms in the Fourier frequency-wavenumber (f-k) domain introduced in seismic imaging in the 70’s. The literature shows that f-k methods offer a numerical advantage over the more conventional time-domain focusing algorithms. On the other hand, the rise of transducer arrays has allowed for the exploration of new emission modes, such as plane wave emissions in ultra-fast medical imaging. In this thesis, we propose to combine fast f-k algorithms with plane wave emissions to form 2D and 3D images as fast as possible. These algorithms are adapted to deal with realistic NDT inspection configurations. Analyses of algorithmic complexities, computation times, and image qualities are carried out in 2D, and a comparison with the time-domain Plane Wave Imaging (PWI) shows a clear advantage for f-k methods. This is confirmed in 3D, where we show that Fourier domain algorithms improve image quality while reducing computation times by a factor up to 300 compared to PWI. Finally, the f-k methods are generalized to multi-modal imaging to characterize cracks. The theory, which accounts for mode conversions and reflections at the specimen interfaces, is first presented, and we then demonstrate that it is possible to improve the reconstruction quality thanks to spectral windowing in the image frequency-domain. This spectral filter cancels undesired artifacts caused by interface echoes, and improves the image contrast
Części książek na temat "Reconstructions 2D et 3D"
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Levaillant, Jean-Marc, F. Lamazou, B. Benoit i E. Faivre. "Place de l’échographie 2D-3D dans le bilan de l’infertilité". W Physiologie, pathologie et thérapie de la reproduction chez l’humain, 225–47. Paris: Springer Paris, 2011. http://dx.doi.org/10.1007/978-2-8178-0061-5_20.
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Behuet, Sabrina, Sebastian Bludau, Olga Kedo, Christian Schiffer, Timo Dickscheid, Andrea Brandstetter, Philippe Massicotte, Mona Omidyeganeh, Alan Evans i Katrin Amunts. "A High-Resolution Model of the Human Entorhinal Cortex in the ‘BigBrain’ – Use Case for Machine Learning and 3D Analyses". W Lecture Notes in Computer Science, 3–21. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-82427-3_1.
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AbstractThe ‘BigBrain’ is a high-resolution data set of the human brain that enables three-dimensional (3D) analyses with a 20 µm spatial resolution at nearly cellular level. We use this data set to explore pre-α (cell) islands of layer 2 in the entorhinal cortex (EC), which are early affected in Alzheimer’s disease and have therefore been the focus of research for many years. They appear mostly in a round and elongated shape as shown in microscopic studies. Some studies suggested that islands may be interconnected based on analyses of their shape and size in two-dimensional (2D) space. Here, we characterized morphological features (shape, size, and distribution) of pre-α islands in the ‘BigBrain’, based on 3D-reconstructions of gapless series of cell-body-stained sections. The EC was annotated manually, and a machine-learning tool was trained to identify and segment islands with subsequent visualization using high-performance computing (HPC). Islands were visualized as 3D surfaces and their geometry was analyzed. Their morphology was complex: they appeared to be composed of interconnected islands of different types found in 2D histological sections of EC, with various shapes in 3D. Differences in the rostral-to-caudal part of EC were identified by specific distribution and size of islands, with implications for connectivity and function of the EC. 3D compactness analysis found more round and complex islands than elongated ones. The present study represents a use case for studying large microscopic data sets. It provides reference data for studies, e.g. investigating neurodegenerative diseases, where specific alterations in layer 2 were previously reported.
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Vincent, Chassin, Lacornerie Thomas, Porcheron Denis, Lu Jun, Ma Lin i Li Xiaobo. "Chapitre III • Systèmes d’imagerie « 2D × 2D » et « 3D » fixés au sol et au plafond". W Systèmes d'imagerie intégrés ou associés aux appareils de radiothérapie, 55–78. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-2299-7-003.
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Vincent, Chassin, Lacornerie Thomas, Porcheron Denis, Lu Jun, Ma Lin i Li Xiaobo. "Chapitre III • Systèmes d’imagerie « 2D × 2D » et « 3D » fixés au sol et au plafond". W Systèmes d'imagerie intégrés ou associés aux appareils de radiothérapie, 55–78. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-2299-7.c003.
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Pietroni, Eva. "Experiencing Past, Present, and Future Urban Environments Through Digital Representation, Storytelling, and Simulation". W Digital Cities, 106–25. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190498900.003.0006.
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Digital technologies can have a great impact on the methodological and epistemological research regarding urban contexts, not only for the documentation and reconstruction of the built heritage but also in the simulation and transmission of intangible values. 3D representation is a powerful tool for communication and also for interpretation. It has perceptive and cognitive impact while also providing a visual interface toward making multiple and deeper connections of meaning and contents. The chapter analyzes the approaches commonly adopted in 3D reconstruction of urban contexts. Methodologies, technologies, software, and data are examined, together with possible outputs (2D or 3D GIS, computer-graphic movies, real time or augmented-reality applications) while offering new perspectives. A study case is presented of the Matera Città Narrata project, whose aim was the creation of a multi-channel digital platform able to support public tourism of this World Heritage Site. It includes, for instance, 3D reconstructions of the urban context evolution through eight chronological phases. It also tells the stories behind those ancient sites, provides real fragments of life, as well as myths, events, characters, and memories.
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Pasha, S. "The sagittal curvature of the spine can be a leading cause of scoliosis in pediatric spine". W Studies in Health Technology and Informatics. IOS Press, 2021. http://dx.doi.org/10.3233/shti210424.
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The etiology of the adolescent idiopathic scoliosis (AIS) remains unknown. Variations in the sagittal profile of the spine between the early stage scoliotic and non-scoliotic pediatric patients have been shown. However, no quantitative study has shown the link between the sagittal profile and 3D deformity of the spine. 126 right thoracic scoliosis with spinal and 3D reconstructions were included. A 2D finite element model was developed for each of the sagittal curve types without any deformity in the frontal or axial planes. Physiological loadings were determined from the literature and were applied in the finite element model. The 3D deformation patterns of the models were compared to the 3D spinal patterns of the AIS with the same sagittal type. A significant correlation was found between the 3D deformity of the scoliotic curves and the numerical finite element simulation of the corresponding sagittal profile as determined by pattern correlation, p<0.001. The sagittal curve deformation patterns corresponded to the spinal deformities in the patients with the same sagittal curvature. Finite element models of the spines, representing different sagittal types in 126 AIS patients showed that deformation pattern of the sagittal types changes as a function of the spine curvature and associates with the patterns of 3D spinal deformity in AIS patients with the same sagittal curves. This finding provided evidence that the sagittal curve of the spine can determine the deformity patterns in AIS.
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Pucci, Marina. "Archaeological Research in Pre-Classical Syria and the Canon of Ancient Near Eastern Art and Archaeology". W Testing the Canon of Ancient Near Eastern Art and Archaeology, 66–89. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190673161.003.0003.
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Since the late nineteenth century, developments in academia, politics, and cultural policies have repeatedly transformed archaeological research in Syria and, in turn, the Syrian canon. After reviewing the birth and development of archaeological research in Syria, this chapter presents a survey of exhibitions and publications. A shift is observed from aesthetically motivated assessments of pre-classical Syrian culture in relation to Mesopotamian and Anatolian monuments and chronologies, to a view of Syria as a multicentered entity with its own complex identity and material diversity. Building upon recent perspectives that emphasize archaeological context over formal artistic characteristics, this chapter concludes with a discussion of some non-canonical objects and also proposes that 3D site reconstructions support a better understanding of the conceptualization and various agencies surrounding an object in its ancient context. Ultimately, an archaeologically contextualized canon could serve as a model for a more nuanced picture of the ancient Near East. 3D modeling, ‘Ain et-Tell, archaeology, bēt ḫilāni, Ebla, exhibitions, Mari, museums, Qatna, Syria
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Wickens, Christopher D., i Polly Baker. "Cognitive Issues in Virtual Reality". W Virtual Environments and Advanced Interface Design. Oxford University Press, 1995. http://dx.doi.org/10.1093/oso/9780195075557.003.0024.
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Virtual reality involves the creation of multisensory experience of an environment (its space and events) through artificial, electronic means; but that environment incorporates a sufficient number of features of the non-artificial world that it is experienced as “reality.” The cognitive issues of virtual reality are those that are involved in knowing and understanding about the virtual environment (cognitive: to perceive and to know). The knowledge we are concerned with in this chapter is both short term (Where am I in the environment? What do I see? Where do I go and how do I get there?), and long term (What can and do I learn about the environment as I see and explore it?). Given the recent interest in virtual reality as a concept (Rheingold, 1991; Wexelblat, 1993; Durlach and Mavor, 1994), it is important to consider that virtual reality is not, in fact, a unified thing, but can be broken down into a set of five features, any one of which can be present or absent to create a greater sense of reality. These features consist of the following five points. 1. Three-dimensional (perspective and/or stereoscopic) viewing vs. two-dimensional planar viewing. (Sedgwick, 1986; Wickens et al., 1989). Thus, the geography student who views a 3D representation of the environment has a more realistic view than one who views a 2D contour map. 2. Dynamic vs. static display. A video or movie is more real than a series of static images of the same material. 3. Closed-loop (interactive or learner-centered) vs. open-loop interaction. A more realistic closed-loop mode is one in which the learner has control over what aspect of the learning “world” is viewed or visited. That is, the learner is an active navigator as well as an observer. 4. Inside-out (ego-referenced) vs. outside-in (world-referenced) frame-of-reference. The more realistic inside-out frame-of-reference is one in which the image of the world on the display is viewed from the perspective of the point of ego-reference of the user (that point which is being manipulated by the control). This is often characterized as the property of “immersion.” Thus, the explorer of a virtual undersea environment will view that world from a perspective akin to that of a camera placed on the explorer’s head;
Streszczenia konferencji na temat "Reconstructions 2D et 3D"
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Cote, P., R. Lagabrielle i V. Gautier. "2D and 3D reconstructions using pseudo-rays". W 54th EAEG Meeting. European Association of Geoscientists & Engineers, 1992. http://dx.doi.org/10.3997/2214-4609.201410505.
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Lubin, Pierre, Stéphane Abadie, Stéphane Vincent i Jean-Paul Caltagirone. "Etude du déferlement par modélisation numérique 2D et 3D". W Journées Nationales Génie Côtier - Génie Civil. Editions Paralia, 2002. http://dx.doi.org/10.5150/jngcgc.2002.010-l.
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Yan, Hua, Hui Dou, Guannan Chen i Li Yao. "3D temperature field reconstruction based on the interpolation of 2D acoustic reconstructions". W Fifth International Conference on Machine Vision (ICMV 12), redaktorzy Yulin Wang, Liansheng Tan i Jianhong Zhou. SPIE, 2013. http://dx.doi.org/10.1117/12.2020948.
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Cavalcanti, Marcelo G., John W. Haller i Michael W. Vannier. "Assessment of landmark measurements of craniofacial images from 2D and 3D reconstructions of spiral CT". W Medical Imaging '98, redaktorzy Yongmin Kim i Seong K. Mun. SPIE, 1998. http://dx.doi.org/10.1117/12.312522.
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Mironenko, M. "Verification module for 3D reconstructions of historical and cultural heritage objects in virtual and augmented reality. The problem of combining 2D and 3D materials". W Historical research in the context of data science: Information resources, analytical methods and digital technologies. LLC MAKS Press, 2020. http://dx.doi.org/10.29003/m1834.978-5-317-06529-4/366-370.
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The issues of preparation and selection of historical sources for their integration into the verification module are considered. Examples of using the module for different types of sources are presented. The features of the development of a virtual interface for such tasks are described using the example of pictorial historical sources of the 19th century. The issues of integration of narrative sources into virtual space were also touched upon.
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Kasula, Bhavani V., Leslie Mercado, Pietro Asinari i Michael R. von Spakovsky. "3D Microstructure Reconstructions of Solid Oxide and Proton Exchange Membrane Fuel Cell Electrodes With Applications to Numerical Simulations of Reacting Mixture Flows Using LBM". W ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42937.
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Computational modeling of fuel cell electrode-catalyst layers is an important tool in understanding the different electrochemical reactions and transport phenomena occurring within fuel cell electrodes. Proper modeling of this layer is required for an accurate prediction of cell behavior which in turn can be used for the development of more efficient fuel cells. In macroscopic CFD approaches such layers are typically modeled as infinitely thin interfaces populated by sources and sinks or as very thin homogeneous porous layers. However, these layers are neither infinitely thin nor homogeneous and, thus, modeling in this fashion leads to a loss of information about the microstructure and its varying effects on the reacting mixture flows which pass through and into the structure. Thus, the utility of relying only on such macroscopic representations limits the general applicability of these macroscopic models as tools for design and for predicting fuel cell performance over a wide range of conditions. Furthermore, such macroscopic models cannot aid in the design of the electrode-catalyst layer itself. In order to address this latter point, a microscopic/mesoscopic modeling approach can be used, e.g., the Lattice Boltzmann Method (LBM), which models the reacting mixture flow through the porous microstructure of the electrode-catalyst layer. However, to do so requires reconstructing the porous geometry of this layer which can be done by using 2D microscopic images of cross-sections of the layer to generate 3D geometries from, for example, stochastic models which are relatively cost efficient and lead to similar structures with approximately the same characteristics of porosity, catalyst loading, three-phase boundaries, etc. as the original structure. Two such 3D reconstruction methods, i.e. one based on the granulometry law (one-point statistics) and the other on two-point statistics, are applied to a 2D SEM (scanning electron microscope) image of an SOFC electrode-catalyst layer and to the 2D SEM and TEM (transmission electron microscope) images for such a layer in a PEMFC. Results for these reconstructions are presented as are results for reacting mixture flow simulations through the two different reconstructed 3D SOFC structures using a 3D LBM approach. The development and application of a 3D LBM model for two-phase reacting mixture flows in PEMFC electrode-catalyst layer structures is in progress and will be reported in a future paper.
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Gong, Yifang, i Ruixian Cai. "3D Mean-Stream-Line Method: A New Engineering Approach to the Inverse Problem of 3D Cascade". W ASME 1989 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1989. http://dx.doi.org/10.1115/89-gt-48.
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The Mean-Stream-Line Method proposed by Wu and Brown (1952) for 2D cascade is developed and extended to solve the 3D inverse problem of turbomachine flow. The equations suitable to the 3D case are derived and the well-posed design conditions are discussed within the scope of the annular wall constraint of turbomachines mentioned by Cai (1983). A computer code has been programmed for this method and computation results compare well with 3D incompressible potential analytical solutions. These solutions, discovered by Cai et al. (1984), are similar to turbomachine flow. A comparison of computation results between this method and the conventional 3D potential function method is also presented. However, in solving the inverse problem, the 3D Mean-Stream-Line Method is much more simple and faster than all other methods already available. In addition, some ideas to solve direct and hybrid problems are also suggested.
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Menon, Prahlad G., Nikola Teslovich, Chia-Yuan Chen, Fotis Sotiropoulos, Akif Undar i Kerem Pekkan. "Device Specific Aortic Outflow Cannula Jets Studied Using 2D PIV and High-Performance 3D CFD Simulation". W ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80454.
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In the US, approximately 1 in 100 children are born with a clinically significant congenital heart defect (CHD). The palliative repair of these defects requires complex biventricular and univentricular surgical operations in newborns often smaller than 2 kg. However, recovery after neonatal intervention remains suboptimal 1. A major component of these surgeries is the cardiopulmonary by-pass (CPB) procedure which if prolonged can potentially lead to neurological complications and developmental defects in a young patient. During CPB, tiny aortic cannulae (2–3 mm inner diameter), with micro-scale blood-wetting features transport relatively large blood volumes (0.3 to 1.0 L/min) resulting in high blood flow velocities. Our recent 3D computational fluid dynamics (CFD) simulations of jet flows in device specific cannulae 2 have indicated that the turbulent jet wake at high physiological neonatal extracorporeal life support (ECLS) circuit blood flow rates can potentially have damaging hemolytic effects, when evaluated in a cuboidal flow domain, as well as in in-silico aortic insertion configurations. Such severe flow conditions can result in platelet activation, vascular injuries and blood damage. Despite these risks, cannulation methods have received little attention compared to the effort expended to assure the safety and efficacy of the mechanical circulatory support blood pumps. Qui et al 3 report that cannula problems are the second most frequently reported mechanical complication in ECLS therapy for respiratory cases and the third most frequent complication in cardiac cases. The purpose of this study is to quantitatively evaluate the jet wake region of two popular 8FR pediatric cannulae, DLP Medtronic 77008 and RMI FEM II – 008 – AT (inner diameter ∼1850 microns), using stereo particle image velocimetry (PIV) to validate numerically computed flow fields.
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Jiang, Zhen, Wei Chen i Craig Burkhart. "A Hybrid Approach to 3D Porous Microstructure Reconstruction via Gaussian Random Field". W ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/detc2012-71173.
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Obtaining an accurate three-dimensional (3D) structure of a porous microstructure is important for assessing the material properties based on finite element analysis. While directly obtaining 3D images of the microstructure is impractical under many circumstances, two sets of methods have been developed in the literature to generate (reconstruct) 3D microstructure from its 2D images: one characterizes the microstructure based on certain statistical descriptors, typically two-point correlation function and cluster correlation function, and then performs an optimization process to build a 3D structure that matches those statistical descriptors; the other method models the microstructure using stochastic models like a Gaussian random field (GRF) and generates a 3D structure directly from the function. The former obtains a relatively accurate 3D microstructure, but the optimization process can be very computationally intensive, especially for problems with a large image size; the latter generates a 3D microstructure quickly but sacrifices the accuracy. A hybrid optimization approach of modeling the 3D porous microstructure of random isotropic two-phase materials is proposed in this paper, which combines the two sets of methods and hence maintains the accuracy of the correlation-based method with improved efficiency. The proposed technique is verified for 3D reconstructions based on silica polymer composite images with different volume fractions. A comparison of the reconstructed microstructures and the optimization histories for both the original correlation-based method and our hybrid approach demonstrates the improved efficiency of the approach.
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Dauch, Thilo Ferdinand, Samuel Braun, Lars Wieth, Geoffroy Chaussonnet, Marc Christoph Keller, Rainer Koch i Hans-Jörg Bauer. "Computational Prediction of Primary Breakup in Fuel Spray Nozzles for Aero-Engine Combustors". W ILASS2017 - 28th European Conference on Liquid Atomization and Spray Systems. Valencia: Universitat Politècnica València, 2017. http://dx.doi.org/10.4995/ilass2017.2017.4693.
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Primary breakup of liquid fuel in the vicinity of fuel spray nozzles as utilized in aero-engine combustors is numericallyinvestigated. As grid based methods exhibit a variety of disadvantages when it comes to the prediction of multi- phase flows, the ”Smoothed Particle Hydrodynamics“ (SPH)-method is employed. The eligibility of the method to analyze breakup of fuel has been demonstrated in recent publications by Braun et al, Dauch et al and Koch et al [1, 2, 3, 4]. In the current paper a methodology for the investigation of the two-phase flow in the vicinity of fuel spray nozzles at typical operating conditions is proposed. Due to lower costs in terms of computing time, 2D predictions are desired. However, atomization of fluids is inherently three dimensional. Hence, differences between 2D and 3D predictions are to be expected. In course of this study, predictions in 2D and based on a 3D sector are presented.Differences in terms of gaseous flow, ligament shape and mixing are assessed.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4693
Raporty organizacyjne na temat "Reconstructions 2D et 3D"
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Chapman, Ray, Phu Luong, Sung-Chan Kim i Earl Hayter. Development of three-dimensional wetting and drying algorithm for the Geophysical Scale Transport Multi-Block Hydrodynamic Sediment and Water Quality Transport Modeling System (GSMB). Engineer Research and Development Center (U.S.), lipiec 2021. http://dx.doi.org/10.21079/11681/41085.
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The Environmental Laboratory (EL) and the Coastal and Hydraulics Laboratory (CHL) have jointly completed a number of large-scale hydrodynamic, sediment and water quality transport studies. EL and CHL have successfully executed these studies utilizing the Geophysical Scale Transport Modeling System (GSMB). The model framework of GSMB is composed of multiple process models as shown in Figure 1. Figure 1 shows that the United States Army Corps of Engineers (USACE) accepted wave, hydrodynamic, sediment and water quality transport models are directly and indirectly linked within the GSMB framework. The components of GSMB are the two-dimensional (2D) deep-water wave action model (WAM) (Komen et al. 1994, Jensen et al. 2012), data from meteorological model (MET) (e.g., Saha et al. 2010 - http://journals.ametsoc.org/doi/pdf/10.1175/2010BAMS3001.1), shallow water wave models (STWAVE) (Smith et al. 1999), Coastal Modeling System wave (CMS-WAVE) (Lin et al. 2008), the large-scale, unstructured two-dimensional Advanced Circulation (2D ADCIRC) hydrodynamic model (http://www.adcirc.org), and the regional scale models, Curvilinear Hydrodynamics in three dimensions-Multi-Block (CH3D-MB) (Luong and Chapman 2009), which is the multi-block (MB) version of Curvilinear Hydrodynamics in three-dimensions-Waterways Experiments Station (CH3D-WES) (Chapman et al. 1996, Chapman et al. 2009), MB CH3D-SEDZLJ sediment transport model (Hayter et al. 2012), and CE-QUAL Management - ICM water quality model (Bunch et al. 2003, Cerco and Cole 1994). Task 1 of the DOER project, “Modeling Transport in Wetting/Drying and Vegetated Regions,” is to implement and test three-dimensional (3D) wetting and drying (W/D) within GSMB. This technical note describes the methods and results of Task 1. The original W/D routines were restricted to a single vertical layer or depth-averaged simulations. In order to retain the required 3D or multi-layer capability of MB-CH3D, a multi-block version with variable block layers was developed (Chapman and Luong 2009). This approach requires a combination of grid decomposition, MB, and Message Passing Interface (MPI) communication (Snir et al. 1998). The MB single layer W/D has demonstrated itself as an effective tool in hyper-tide environments, such as Cook Inlet, Alaska (Hayter et al. 2012). The code modifications, implementation, and testing of a fully 3D W/D are described in the following sections of this technical note.