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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Développement de nouveaux plans d'expériences uniformes adaptés à la simulation numérique en grande dimension

Santiago, Jenny 04 February 2013 (has links)
Cette thèse propose une méthodologie pour des études en simulation numérique en grande dimension. Elle se décline en différentes étapes : construction de plan d'expériences approprié, analyse de sensibilité et modélisation par surface de réponse. Les plans d'expériences adaptés à la simulation numérique sont les "Space Filling Designs", qui visent à répartir uniformément les points dans l'espace des variables d'entrée. Nous proposons l'algorithme WSP pour construire ces plans, rapidement, avec de bons critères d'uniformité, même en grande dimension. Ces travaux proposent la construction d'un plan polyvalent, qui sera utilisé pour les différentes étapes de l'étude : de l'analyse de sensibilité aux surfaces de réponse. L'analyse de sensibilité sera réalisée avec une approche innovante sur les points de ce plan, pour détecter le sous-ensemble de variables d'entrée réellement influentes. Basée sur le principe de la méthode de Morris, cette approche permet de hiérarchiser les variables d'entrée selon leurs effets. Le plan initial est ensuite "replié" dans le sous-espace des variables d'entrée les plus influentes, ce qui nécessite au préalable une étude pour vérifier l'uniformité de la répartition des points dans l'espace réduit et ainsi détecter d'éventuels amas et/ou lacunes. Ainsi, après réparation, ce plan est utilisé pour l'étape ultime : étude de surfaces de réponse. Nous avons alors choisi d'utiliser l'approche des Support Vector Regression, indépendante de la dimension et rapide dans sa mise en place. Obtenant des résultats comparables à l'approche classique (Krigeage), cette technique semble prometteuse pour étudier des phénomènes complexes en grande dimension. / This thesis proposes a methodology of study in numeric simulation for high dimensions. There are several steps in this methodology : setting up an experimental design, performing sensitivity analysis, then using response surface for modelling. In numeric simulation, we use a Space Filling Design that scatters the points in the entire domain. The construction of an experimental design in high dimensions must be efficient, with good uniformity properties. Moreover, this construction must be fast. We propose using the WSP algorithm to construct such an experimental design. This design is then used in all steps of the methodology, making it a versatile design, from sensitivity analysis to modelling. A sensitivity analysis allows identifying the influent factors. Adapting the Morris method principle, this approach classifies the inputs into three groups according to their effects. Then, the experimental design is folded over in the subspace of the influent inputs. This action can modify the uniformity properties of the experimental design by creating possible gaps and clusters. So, it is necessary to repair it by removing clusters and filling gaps. We propose a step-by-step approach to offer suitable repairing for each experimental design. Then, the repaired design is used for the final step: modelling from the response surface. We consider a Support Vector Machines method because dimension does not affect the construction. Easy to construct and with good results, similar to the results obtained by Kriging, the Support Vector Regression method is an alternative method for the study of complex phenomena in high dimensions.
122

Segmentation d'images de documents manuscrits composites : application aux documents de chimie / Heterogenous handwritten document image segmentation : application to chemistry document

Ghanmi, Nabil 30 September 2016 (has links)
Cette thèse traite de la segmentation structurelle de documents issus de cahiers de chimie. Ce travail est utile pour les chimistes en vue de prendre connaissance des conditions des expériences réalisées. Les documents traités sont manuscrits, hétérogènes et multi-scripteurs. Bien que leur structure physique soit relativement simple, une succession de trois régions représentant : la formule chimique de l’expérience, le tableau des produits utilisés et un ou plusieurs paragraphes textuels décrivant le déroulement de l’expérience, les lignes limitrophes des régions portent souvent à confusion, ajouté à cela des irrégularités dans la disposition des cellules du tableau, rendant le travail de séparation un vrai défi. La méthodologie proposée tient compte de ces difficultés en opérant une segmentation à plusieurs niveaux de granularité, et en traitant la segmentation comme un problème de classification. D’abord, l’image du document est segmentée en structures linéaires à l’aide d’un lissage horizontal approprié. Le seuil horizontal combiné avec une tolérance verticale avantage le regroupement des éléments fragmentés de la formule sans trop fusionner le texte. Ces structures linéaires sont classées en Texte ou Graphique en s’appuyant sur des descripteurs structurels spécifiques, caractéristiques des deux classes. Ensuite, la segmentation est poursuivie sur les lignes textuelles pour séparer les lignes du tableau de celles de la description. Nous avons proposé pour cette classification un modèle CAC qui permet de déterminer la séquence optimale d’étiquettes associées à la séquence des lignes d’un document. Le choix de ce type de modèle a été motivé par sa capacité à absorber la variabilité des lignes et à exploiter les informations contextuelles. Enfin, pour le problème de la segmentation de tableaux en cellules, nous avons proposé une méthode hybride qui fait coopérer deux niveaux d’analyse : structurel et syntaxique. Le premier s’appuie sur la présence des lignes graphiques et de l’alignement de texte et d’espaces ; et le deuxième tend à exploiter la cohérence de la syntaxe très réglementée du contenu des cellules. Nous avons proposé, dans ce cadre, une approche contextuelle pour localiser les champs numériques dans le tableau, avec reconnaissance des chiffres isolés et connectés. La thèse étant effectuée dans le cadre d’une convention CIFRE, en collaboration avec la société eNovalys, nous avons implémenté et testé les différentes étapes du système sur une base conséquente de documents de chimie / This thesis deals with chemistry document segmentation and structure analysis. This work aims to help chemists by providing the information on the experiments which have already been carried out. The documents are handwritten, heterogeneous and multi-writers. Although their physical structure is relatively simple, since it consists of a succession of three regions representing: the chemical formula of the experiment, a table of the used products and one or more text blocks describing the experimental procedure, several difficulties are encountered. In fact, the lines located at the region boundaries and the imperfections of the table layout make the separation task a real challenge. The proposed methodology takes into account these difficulties by performing segmentation at several levels and treating the region separation as a classification problem. First, the document image is segmented into linear structures using an appropriate horizontal smoothing. The horizontal threshold combined with a vertical overlapping tolerance favor the consolidation of fragmented elements of the formula without too merge the text. These linear structures are classified in text or graphic based on discriminant structural features. Then, the segmentation is continued on text lines to separate the rows of the table from the lines of the raw text locks. We proposed for this classification, a CRF model for determining the optimal labelling of the line sequence. The choice of this kind of model has been motivated by its ability to absorb the variability of lines and to exploit contextual information. For the segmentation of table into cells, we proposed a hybrid method that includes two levels of analysis: structural and syntactic. The first relies on the presence of graphic lines and the alignment of both text and spaces. The second tends to exploit the coherence of the cell content syntax. We proposed, in this context, a Recognition-based approach using contextual knowledge to detect the numeric fields present in the table. The thesis was carried out in the framework of CIFRE, in collaboration with the eNovalys campany.We have implemented and tested all the steps of the proposed system on a consequent dataset of chemistry documents
123

Análise da correlação entre tipos histológicos de carcinoma basocelular encontrados nas biópsias pré-operatórias e respectivas peças cirúrgicas / Correlation between histological types of basal cell carcinoma found in preoperative biopsies and respective surgical specimens

Messina, Maria Cristina de Lorenzo 11 May 2005 (has links)
O carcinoma basocelular (CBC) é tumor constituído por diferentes tipos histológicos, que demonstram diverso potencial de agressividade. Sabe-se que a correlação entre os tipos histológicos de CBC encontrados no material de biópsia pré-operatória e no material da peça cirúrgica excisional não é total. Na literatura esta correlação varia de 42,7 a 80,0% quando analisados os tipos histológicos predominantes (THP). No presente estudo foi feita análise retrospectiva de 70 casos de CBC primário submetidos a biópsia préoperatória e cirurgia excisional. A amostra foi analisada estatisticamente quanto ao gênero e idade dos doentes e localização anatômica dos CBC, demonstrando ser comparável aos demais estudos da literatura. Também foram avaliados o tamanho médio tumoral e o tipo de reconstrução utilizado. A média do maior eixo dos CBC foi de 20 mm e 54% dos casos necessitaram reconstrução complexa, como retalhos e enxertos, mostrando ser amostra representativa de tumores de médio a grande porte. A avaliação histológica foi feita de modo padronizado, determinando tanto o THP quanto os tipos histológicos acessórios (THA) encontrados no material das biópsias pré-operatórias e nas peças cirúrgicas excisionais. Houve 78,3% de correlação entre THP da biópsia e peça cirúrgica, 87,0% de correlação entre THP e/ou THA da biópsia e THP da peça cirúrgica e 92,7% de correlação entre tipos agressivos ou não agressivos. Conclui-se que a biópsia préoperatória é útil para predizer o THP de CBC da peça cirúrgica excisional na maioria dos casos. No entanto, é importante ressaltar que, quando descrito apenas o THP encontrado na biópsia, ocorre 21,7% de falha no diagnóstico. Quando descritos THP e THA encontrados na biópsia a falha diagnóstica cai para 13%. Quando a intenção da biópsia for a determinação da presença de tipos de CBC agressivos ou não, a falha no diagnóstico é de apenas 7,3% / Basal cell carcinoma (BCC) is a tumor presenting many histological types, each one possessing a specific aggressivity potential. It\'s known that correlation between histological types found in preoperative biopsy specimens and excisional surgery specimens is not total. When correlation between predominant histological types (PHT) is analyzed, concordance value varies from 42,7 to 80,0% in the literature. In the present study 70 primary BCC submitted to preoperative biopsy and excisional surgery were retrospectively analyzed. The sample was statistically analyzed in terms of patients\' gender and age and anatomical location of the tumour and was found to be similar to other reports in the literature. Average size of tumors and type of surgical reconstruction employed were also evaluated. Average size of the largest tumour axis was 20 mm and 54% of the cases needed complex reconstructions, such as flaps and grafts, demonstrating that the sample was represented by medium to large sized tumors. Histological evaluation was made in a patterned way, determining PHT and accessory histological types (AHT) in both preoperative biopsies and excisional surgery specimens. Results obtained were: 78.3% correlation between biopsy PHT and excisional surgery PHT, 87.0% correlation between biopsy PHT and/or AHT and excisional surgery PHT and 92.7% correlation when BCC were classified as \"aggressive\" or \"non aggressive\" . Conclusion: preoperative biopsy is useful to predict BCC\'s PHT of excisional surgery specimen in most cases. However, it\'s important to note that when biopsy findings are limited to the description of the PHT , there is a 21.7% diagnostic failure. When both PHT and AHT found in biopsy are described, diagnostic failure falls to 13%. When the intention is determining the presence of aggressive or non aggressive types of BCC, diagnostic failure is only 7.3%
124

Radiative properties computational modeling of porous cellular materials / Modélisation informatique de matières cellulaires poreuses

Cunsolo, Salvatore 23 January 2018 (has links)
Les transferts thermiques par rayonnement dans des mousses sont modélisés à partir de la morphologie du matériau et des propriétés de sa phase solide. Dans ce travail de thèse, une attention particulière est portée sur les modèles radiatifs de Monte Carlo. Les différentes approches d’homogénéisation telles que « Homogeneous Phase » (HPA) and « Multi Phase » (MPA) sont discutées et comparées. Des développements novateurs sont proposés pour améliorer la précision des résultats. Nos avancées permettent de générer numériquement trois types de mousses périodiques couvrant un large domaine de matériaux cellulaires: mousse à pores fermés à haute porosité, mousse à cellules ouvertes à basse et haute porosité. Pour ces dernières, des comparaisons morphologiques avec des données expérimentales tomographiques, montrent des résultats satisfaisants et tendent à valider nos modèles de génération. Des mousses dont la phase solide est opaque ont tout d’abord été étudiées. Nos simulations ont permis de trouver de nouvelles lois analytiques précises permettant d’estimer les propriétés radiatives de ces matériaux à partir de données morphologiques. Ensuite, nous avons considéré des mousses, dont la phase solide est semi transparente. La modélisation du transfert radiatif au sein de ces milieux cellulaires est plus complexe. Les méthodes de modélisation des propriétés radiatives de la littérature, HPA et MPA, sont testées. Des simulations de Monte carlo directes dans les matériaux ont permis de mettre en exergue les limites de ces modèles. Des modèles novateurs ont été proposés afin d’ améliorer la précision des simulations. Ils sont basés sur une méthode hybride directe-inverse et une modification de l’équation de transfert radiatif classique. Ces nouveaux modèles (HPA+ et MPA+) ont été testés sur un ensemble varié de morphologies générées numériquement. Les modèles améliorés sont systématiquement plus précis que les modèles existants / Cellular media such as plastic, ceramic and metal foams present specific characteristics that make them interesting for a number of applications related to thermal engineering. Their ability to minimize natural convection makes them ideal candidates for insulation applications, while the high specific surface and permeability to fluid of open cell foams makes them interesting heat transfer enhancers. In addition, their permeability to light makes them an ideal candidate for thermal radiation based applications, such as porous burners or solar energy collectors. In many of these application, thermal radiation heat transfer can have a significant influence on the heat transfer process. Both accurate radiation models and accurate morphological models of the structure of the foam are required. This work provides an original contribution on both these accounts. A discussion of the literature on numerical methods for radiation heat transfer in cellular media is presented, with focus on Monte Carlo methods. Homogeneous Phase (HPA) and Multi Phase (MPA) methods are discussed. Further efforts are required to accurately model and digitally replicate of foam morphologies. Our goal is to digitally generate three commonly occurring types of foam structures, covering a large range of real materials: high-porosity open cell foams, high-porosity closed cell foams, low-porosity open-cell structures. For high-porosity open cell foams, the automated parametric digital generation technique was validated against a dataset consisting of raw morphological data obtained by tomographic analysis. The generation capabilities were then applied to parametrically investigate the influence of morphological parameters on the radiative properties (namely, the extinction coefficient) of an opaque open-cell foam. Highly accurate analytical relationships were subsequently deduced and validated by comparison with results obtained from tomography samples. Modeling radiation in foams with a semi-transparent solid phase is substantially more complex. A Direct Monte-Carlo Homogenization reference technique is proposed, that allows to simulate radiation within arbitrary cavities and calculate macroscopic radiative quantities based on a Representative Elementary Volume (REV) of cellular material. The technique is validated against full scale Monte Carlo simulations. Improvements of the existing Homogeneous Phase and Multi Phase approach are proposed, through extensive use of inverse methods and the addition of one equation to take into account specific phenomena taking place in the semi-transparent solid phase. The resulting Improved Homogenized Approaches are extensively tested by comparing them with Direct Monte Carlo Homogenization simulations and existing homogenized models, on a varied set of morphologies making full use of the previously developed digital generation techniques. The improved models consistently outperform existing homogenized models.
125

A transmission-error-based gear dynamic model : Applications to single- and multi-mesh transmissions / Modèle dynamique d'engrenages basé sur l'erreur de transmission : Applications à des transmissions simple et multi-étages

Sainte-Marie, Nina 09 December 2016 (has links)
Les spectres de bruit mesurés en cabine d’hélicoptère montrent que la boîte de transmission principale (BTP) est un des principaux contributeurs au bruit perçu par les usagers. Elle génère en effet plusieurs raies émergeant fortement du bruit large bande et dont les fréquences se situent dans la plage de sensibilité maximale de l’oreille humaine. Dans un contexte d’amélioration permanente du confort acoustique des usagers, un modèle numérique est développé pour prédire le comportement dynamique des BTP. Les équations du mouvement sont écrites sur la base de fonctions du temps représentatives des excitations générées par l’engrènement (raideur d’engrènement et erreurs de transmission). Plusieurs éléments de validation sont présentés pour confirmer la pertinence de la formulation proposée. Différents résultats numériques et expérimentaux de la littérature sont utilisés à des fins de comparaison, montrant que le modèle s’applique aux systèmes à simple étage de réduction, par engrenage cylindrique ou spiro-conique. La validation est ensuite étendue aux systèmes à deux étages de réduction et les résultats confirment que la formulation basée sur les erreurs de transmission permet de tenir compte des corrections de profil. Finalement, le modèle est utilisé pour diverses applications. Premièrement, l’influence des erreurs de pas sur le comportement dynamique de transmissions par engrenages est discutée, ainsi que l’influence combinée du niveau de chargement appliqué. Dans un second temps, la relation entre l’erreur de transmission dynamique et différents coefficients dynamiques est étudiée. Le contenu spectral de la réponse au niveau des roulements est ensuite analysé pour des systèmes à deux engrènements cylindriques et l’influence de différents paramètres est discutée. Enfin, une application est réalisée sur un système comprenant un engrenage cylindrique et un engrenage spiro-conique. Les phénomènes de couplage entre les étages successifs sont mis en évidence ainsi que la contribution des deux engrènements au contenu spectral de la réponse aux roulements. / Noise measurements have shown that helicopters main gearboxes highly contribute to the overall cabin noise. Gear mesh vibrations propagate through the shafts to the rolling element bearings and the casing which becomes a source of radiated noise. The latter is characterized by high-amplitude tones emerging from broadband noise whose frequencies lie in the range of maximum human ear sensitivity. In the context of continuous improvement in the acoustic comfort of helicopter passengers, it is therefore necessary to analyse and optimize gearbox vibrations in order to reduce casing noise radiations. The research work presented in this memoir is focused on the development of a numerical model dedicated to the prediction of gear system dynamic behaviour, comprising several gear stages and different types of gears. This model relies on classic beam and lumped parameter elements along with specific two-node gear elements for both cylindrical (spur, helical) and spiral-bevel gears. The equations of motion are developed based on time-varying functions representative of mesh excitations which comprise: (a) mesh stiffness functions, (b) quasi-static transmission error under load, and (c) kinematic (or no-load) transmission error. A number of comparisons with benchmark numerical and experimental results from the literature are presented which demonstrate that the proposed approach is sound as far as single-stage systems with spur, helical or spiral-bevel gears are considered. Validations are then extended to double-stage gears and, here again, it is confirmed that the proposed transmission error based formulation is accurate and can account for tooth shape modifications. In the second part of the memoir, several examples of application are presented and commented upon. First, the combined influence of tooth pitch errors and load on the dynamic behaviour of gear transmissions is tackled. An extended three-dimensional model and a reduced torsional version are then confronted in order to investigate the dependency between dynamic transmission errors and mesh force / root stress dynamic factors. Further investigations on bearing dynamic response in two-stage spur gear systems are conducted and the particular contributions of profile modifications are analysed. Finally, a system combining a cylindrical gear and a spiral-bevel gear is considered and particular attention is paid to the dynamic couplings between the various meshes and their influence on bearing dynamic responses.
126

Os saberes dos professores de educação infantil em relação à construção numérica: formação de professores em um grupo cooperativo

Garcia, Marinete da Fontoura 21 September 2006 (has links)
Made available in DSpace on 2016-04-27T16:57:53Z (GMT). No. of bitstreams: 1 dissertacao_marinete_fontoura_garcia.pdf: 592464 bytes, checksum: c714eb2a28776b300b99c76808bc6186 (MD5) Previous issue date: 2006-09-21 / This work treats of the formation in service of teachers of Infantile Education and yours know in relation to the process of numeric construction. Organized starting from reflections and observations produced through discussions in a group of studies with professionals of a same school unit, did it stop in the following subject: How are the teachers that participate in a cooperative group, going building new you know and new forms of to understand and to work with the numeric construction, developing a posture of investigating teacher?. The qualitative approach of research was used, initially with the application of individual interviews, following by the formation of a group of studies, that checked to the work a cooperation nature between the participant teachers and the researcher; this felt through studies, choice, application and reflection of teaching activities Leaning in researchers' investigations that studied the numeric construction, it tries to evidence, through the reports presented in the interviews and in the discussions of the cooperative group (involving teachers of Infantile Education that they teach in the municipal net of a municipal district of Great São Paulo), as they feels the pedagogic practice in relation to the numeric construction and in that measured that practice can change through the teachers' participation in a cooperative group. In this group, the teachers discussed texts, they investigated their own students, they promoted discussions and they analyzed the results of the investigations to the light of the theoretical referential. Results of researches and studies already accomplished, about the numeric construction, they are little published and, through the interviews, it was verified that the teachers, doesn't tend access to such studies, they don't consider the children's hypotheses concerning the numbers. Like this, the work has as purpose to contribute with the teachers' pedagogic practice, presenting and developing relative subjects to the axis Mathematics in Infantile Education / Este trabalho trata da formação em serviço de Professoras de Educação Infantil e seus saberes em relação ao processo de construção numérica. Organizado a partir de reflexões e observações produzidas por meio de discussões em um grupo de estudos com profissionais de uma mesma unidade escolar, deteve-se na seguinte questão: Como as professoras, que participam de um grupo cooperativo, vão construindo novos saberes e novas formas de compreender e lidar com a construção numérica, desenvolvendo uma postura de professora investigadora? . Foi utilizada a abordagem qualitativa de pesquisa, inicialmente com a aplicação de entrevistas individuais, seguida da formação de um grupo de estudos, que conferiu ao trabalho uma natureza de cooperação entre as professoras participantes e a pesquisadora; isto se deu por meio de estudos, escolha, aplicação e reflexão de atividades de ensino Apoiado em investigações de pesquisadores que estudaram a construção numérica, procura evidenciar, por meio dos relatos apresentados nas entrevistas e nas discussões do grupo cooperativo (envolvendo professoras de Educação Infantil que lecionam na rede municipal de um município da Grande São Paulo), como se dá a prática pedagógica em relação à construção numérica e em que medida essa prática pode mudar por meio da participação das professoras em um grupo cooperativo. Neste grupo, as professoras discutiram textos, investigaram seus próprios alunos, promoveram discussões e analisaram os resultados das investigações à luz dos referenciais teóricos. Resultados de pesquisas e estudos já realizados, sobre a construção numérica, são pouco divulgados e, por meio das entrevistas, verificou-se que as professoras, não tendo acesso a tais estudos, não consideram as hipóteses das crianças acerca dos números. Assim, o trabalho tem como finalidade contribuir com a prática pedagógica das professoras, apresentando e desenvolvendo questões relativas ao eixo Matemática em Educação Infantil
127

Desenvolvimento de um aplicativo em CAD para auxiliar o processo de fabricação em produtos de caldeiraria para hidrelétricas / Development of a CAD application to improve the manufacturing process of hydroelectric weld parts

Prado, Victor 14 December 2004 (has links)
O planejamento da fabricação de peças de caldeiraria para hidrelétricas tais como caixa espiral, tubo de sucção e conduto forçado, necessita de bons conhecimentos em caldeiraria e muita experiência na área devido à complexidade dos cálculos, tornando-se uma tarefa trabalhosa e com muitas possibilidades de erros. A seqüência de operações, no entanto, é altamente repetitiva facilitando o desenvolvimento de um sistema computacional de apoio. O trabalho proposto a seguir tem como objetivo apresentar um sistema desenvolvido como um aplicativo em software CAD para auxiliar as tarefas de projetar e fabricar caixa espiral, tubo de sucção e conduto forçado. O sistema colocou o conhecimento técnico da engenharia industrial de hidrogeradores de uma empresa de bens de capital ao alcance de projetistas desta área, de forma a aumentar a produtividade nestas, e em outras atividades similares, minimizando as possibilidades de erro e padronizando os procedimentos de cálculos. Os resultados foram, entre outros, diminuição do tempo de geração das informações para o processo de fabricação, tais como croquis de delineamento e desenhos de montagem, acima de 90% e perda zero de peças na fabricação. / The manufacturing process of hydroelectric weld parts, such as spiral cases, draft tubes and penstocks, demands good knowledge and experience in the area due to the calculations needed, revealing to be a difficult work with a high risk of errors. However, the operation sequence is highly repetitive which enables the development of a computational support system. This thesis has the purpose to present a system developed as an application in CAD software to aid the projecting and manufacturing activities of the spiral boxes, draft tubes and penstocks. Such system was disposed to the technical body of an industrial engineering department maintained by a heavy equipment company which manufactures hydro generators, so professionals were able to increase their productivity, being the system also used in similar areas, minimizing possibilities of mistakes and standardizing calculations procedures. Results were, among others, decrease of time needed to develop process information, such as sketch outlines and assembly drawings, above 90% and zero losses on parts production.
128

Desenvolvimento de um aplicativo em CAD para auxiliar o processo de fabricação em produtos de caldeiraria para hidrelétricas / Development of a CAD application to improve the manufacturing process of hydroelectric weld parts

Victor Prado 14 December 2004 (has links)
O planejamento da fabricação de peças de caldeiraria para hidrelétricas tais como caixa espiral, tubo de sucção e conduto forçado, necessita de bons conhecimentos em caldeiraria e muita experiência na área devido à complexidade dos cálculos, tornando-se uma tarefa trabalhosa e com muitas possibilidades de erros. A seqüência de operações, no entanto, é altamente repetitiva facilitando o desenvolvimento de um sistema computacional de apoio. O trabalho proposto a seguir tem como objetivo apresentar um sistema desenvolvido como um aplicativo em software CAD para auxiliar as tarefas de projetar e fabricar caixa espiral, tubo de sucção e conduto forçado. O sistema colocou o conhecimento técnico da engenharia industrial de hidrogeradores de uma empresa de bens de capital ao alcance de projetistas desta área, de forma a aumentar a produtividade nestas, e em outras atividades similares, minimizando as possibilidades de erro e padronizando os procedimentos de cálculos. Os resultados foram, entre outros, diminuição do tempo de geração das informações para o processo de fabricação, tais como croquis de delineamento e desenhos de montagem, acima de 90% e perda zero de peças na fabricação. / The manufacturing process of hydroelectric weld parts, such as spiral cases, draft tubes and penstocks, demands good knowledge and experience in the area due to the calculations needed, revealing to be a difficult work with a high risk of errors. However, the operation sequence is highly repetitive which enables the development of a computational support system. This thesis has the purpose to present a system developed as an application in CAD software to aid the projecting and manufacturing activities of the spiral boxes, draft tubes and penstocks. Such system was disposed to the technical body of an industrial engineering department maintained by a heavy equipment company which manufactures hydro generators, so professionals were able to increase their productivity, being the system also used in similar areas, minimizing possibilities of mistakes and standardizing calculations procedures. Results were, among others, decrease of time needed to develop process information, such as sketch outlines and assembly drawings, above 90% and zero losses on parts production.
129

Análise da correlação entre tipos histológicos de carcinoma basocelular encontrados nas biópsias pré-operatórias e respectivas peças cirúrgicas / Correlation between histological types of basal cell carcinoma found in preoperative biopsies and respective surgical specimens

Maria Cristina de Lorenzo Messina 11 May 2005 (has links)
O carcinoma basocelular (CBC) é tumor constituído por diferentes tipos histológicos, que demonstram diverso potencial de agressividade. Sabe-se que a correlação entre os tipos histológicos de CBC encontrados no material de biópsia pré-operatória e no material da peça cirúrgica excisional não é total. Na literatura esta correlação varia de 42,7 a 80,0% quando analisados os tipos histológicos predominantes (THP). No presente estudo foi feita análise retrospectiva de 70 casos de CBC primário submetidos a biópsia préoperatória e cirurgia excisional. A amostra foi analisada estatisticamente quanto ao gênero e idade dos doentes e localização anatômica dos CBC, demonstrando ser comparável aos demais estudos da literatura. Também foram avaliados o tamanho médio tumoral e o tipo de reconstrução utilizado. A média do maior eixo dos CBC foi de 20 mm e 54% dos casos necessitaram reconstrução complexa, como retalhos e enxertos, mostrando ser amostra representativa de tumores de médio a grande porte. A avaliação histológica foi feita de modo padronizado, determinando tanto o THP quanto os tipos histológicos acessórios (THA) encontrados no material das biópsias pré-operatórias e nas peças cirúrgicas excisionais. Houve 78,3% de correlação entre THP da biópsia e peça cirúrgica, 87,0% de correlação entre THP e/ou THA da biópsia e THP da peça cirúrgica e 92,7% de correlação entre tipos agressivos ou não agressivos. Conclui-se que a biópsia préoperatória é útil para predizer o THP de CBC da peça cirúrgica excisional na maioria dos casos. No entanto, é importante ressaltar que, quando descrito apenas o THP encontrado na biópsia, ocorre 21,7% de falha no diagnóstico. Quando descritos THP e THA encontrados na biópsia a falha diagnóstica cai para 13%. Quando a intenção da biópsia for a determinação da presença de tipos de CBC agressivos ou não, a falha no diagnóstico é de apenas 7,3% / Basal cell carcinoma (BCC) is a tumor presenting many histological types, each one possessing a specific aggressivity potential. It\'s known that correlation between histological types found in preoperative biopsy specimens and excisional surgery specimens is not total. When correlation between predominant histological types (PHT) is analyzed, concordance value varies from 42,7 to 80,0% in the literature. In the present study 70 primary BCC submitted to preoperative biopsy and excisional surgery were retrospectively analyzed. The sample was statistically analyzed in terms of patients\' gender and age and anatomical location of the tumour and was found to be similar to other reports in the literature. Average size of tumors and type of surgical reconstruction employed were also evaluated. Average size of the largest tumour axis was 20 mm and 54% of the cases needed complex reconstructions, such as flaps and grafts, demonstrating that the sample was represented by medium to large sized tumors. Histological evaluation was made in a patterned way, determining PHT and accessory histological types (AHT) in both preoperative biopsies and excisional surgery specimens. Results obtained were: 78.3% correlation between biopsy PHT and excisional surgery PHT, 87.0% correlation between biopsy PHT and/or AHT and excisional surgery PHT and 92.7% correlation when BCC were classified as \"aggressive\" or \"non aggressive\" . Conclusion: preoperative biopsy is useful to predict BCC\'s PHT of excisional surgery specimen in most cases. However, it\'s important to note that when biopsy findings are limited to the description of the PHT , there is a 21.7% diagnostic failure. When both PHT and AHT found in biopsy are described, diagnostic failure falls to 13%. When the intention is determining the presence of aggressive or non aggressive types of BCC, diagnostic failure is only 7.3%
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Modélisation multi-échelle du comportement hydro-méchanique des roches argileuses / Multi-scale modelling of the hydro-mechanical behaviour of argillaceuous rocks

Van Den Eijnden, Bram 13 July 2015 (has links)
Les études de faisabilité concernant le stockage géologique profond des déchets radioactifs ont conduit un intérêt accru concernant la modélisation géomécanique de la roche hte. En France, une roche hte potentielle est l'argilite du Callovo-Oxfordien du site de Meuse/Haute Marne. Etant donné que le principe de stockage géologique profond repose fortement sur la capacité de confinement de la formation hte, sa faible perméabilité est d'une importance clé. La perméabilité étant dépendante de la microstructure du matériau et de son évolution sous chargement, le comportement couplé hydro-mécanique de l'argilite est important. En effet, des modifications mécaniques sont induites par le creusement de la galerie d'entreposage, générant une zone endommagée (EDZ), pouvant conduire une modification de la perméabilité dans le voisinage de la galerie. Dans les matériaux microstructure complexe comme l'argilite du Callovo-Oxfordien, le comportement macroscopique trouve son origine dans l'interaction des constituants micro-mécaniques. En plus du couplage entre le comportement hydraulique et mécanique, un couplage entre les échelles micro et macro existe. Par le biais de l'élaboration d'un cadre d'homogénéisation du couplage hydro-mécanique, une approche de modélisation deuxéchelles est développée dans ce travail, dans laquelle la relation constitutive macroscopique découle directement du comportement à l'échelle microscopique. Un modèle existant du couplage hydro-mécanique, reposant sur l'identification de grains et d'espaces poreux intergranulaires à l'échelle micro est adopté comme point de départ. Ce modèle repose sur une homogénéisation numérique du comportement à la petite échelle afin d'obtenir à l'échelle macroscopique la réponse en contrainte et de transport du fluide interstitiel. Ce modèle est basé sur un VER périodique qui permet de déduire le comportement macroscopique local de l'argilite. En réponse, en un point d'intégration macro donné, à un incrément de la déformation et du gradient de pression, la réponse du VER permet d'exprimer l'incrément de contrainte et de flux associé, constituant de fait un équivalent numérique de la relation constitutive. Les problèmes aux conditions limites macro et micro sont traités simultanément par la méthode élément fini. Pour obtenir les opérateurs tangents consistants à l'échelle macro, la méthode d'homogénéisation par condensation statique des opérateurs tangeants micro est étendu au cas avec couplage hydro-mécanique. L'implémentation du modèle double échelle et la mise en uvre des développements théoriques d'homogénéisation ont été effectués dans le code élément fini Lagamine (Université de Liège). Pour la modélisation de la localisation de la déformation à l'échelle macro, qui, dans un formalisme de milieu continu classique, souffre de la dépendance au maillage, l'approche double-échelle a été utilisée dans un formalisme de milieu enrichi de type milieu de second gradient pour matériau poreux saturé. Les capacités du modèle homogénéisé numériquement, utilisé dans un cadre de milieu de second gradient, sont ensuite démontrées par des simulations d'essais dométriques et d'essais de compression biaxiaux. L'approche se confirme être un moyen puissant pour modéliser l'anisotropie initiale et induite du comportement mécanique et du comportement hydraulique. Pour la modélisation du comportement de l'argilite du Callovo-Oxfordien, des VER sont construits en tenant compte des travaux de caractérisation de la géométrie des inclusions microscopiques et des résultats expérimentaux d'essais macroscopiques.La loi de comportement homogénéisée numériquement ainsi calibrée est utilisée dans des simulations de creusement de galerie jusqu'à des niveaux d'endommagement générant une localisation de la déformation.Ces calculs montrent à la fois la pertinence et l'applicabilité du concept double échelle pour l'évaluation du comportement hydromécanique des EDZ dans un contexte du stockage des déchets radioactifs. / Feasibility studies for deep geological radioactive waste disposal facilities have led to an increased interest in the geomechanical modelling of its host rock. In France, a potential host rock is the Callovo-Oxfordian claystone. The low permeability of this material is of key importance, as the principal of deep geological disposal strongly relies on the sealing capacity of the host formation. The permeability being coupled to the mechanical material state, hydromechanical coupled behaviour of the claystone becomes important when mechanical alterations are induced by gallery excavation in the so-called excavation damaged zone (EDZ). In materials with microstructure such as the Callovo-Oxfordian claystone [Robinet et al., 2012], the macroscopic behaviour has its origin in the interaction of its mi- cromechanical constituents. In addition to the coupling between hydraulic and mech- anical behaviour, a coupling between the micro (material microstructure) and macro will be made. By means of the development of a framework of computational homo- genization for hydromechanical coupling, a doublescale modelling approach is formu- lated, for which the macroscale constitutive relations are derived from the microscale by homogenization. An existing model for the modelling of hydromechanical coupling based on the distinct definition of grains and intergranular pore space [Frey, 2010] is adopted and modified to enable the application of first order computational homogenization for obtaining macroscale stress and fluid transport responses. This model is used to constitute a periodic representative elementary volume (REV) that allows the rep- resentation of the local macroscopic behaviour of the claystone. As a response to deformation loading, the behaviour of the REV represents the numerical equivalent of a constitutive relation at the macroscale. For the required consistent tangent operators, the framework of computational homogenization by static condensation [Kouznetsova et al., 2001] is extended to hy- dromechanical coupling. The theoretical developments of this extension are imple- mented in the finite element code Lagamine (Li` ege) as an independent constitutive relation. For the modelling of localization of deformation, which in classical FE meth- ods suffers from the well-known mesh dependency, the doublescale approach of hy- dromechanical coupling is combined with a local second gradient model [Collin et al., 2006] to control the internal length scale of localized deformation. By accepting the periodic boundary conditions as a regularization of the microscale deformation, the use of the multiscale model in combination with the local second gradient model can be used for modelling localization phenomena in HM-coupled settings with material softening. The modelling capacities of the approach are demonstrated by means of simula- tions of oedometer tests and biaxial compression tests. The approach is demonstrated to be a powerful way to model anisotropy in the mechanical as well as the hydraulic behaviour of the material both in the initial material state and as an effect of hy- dromechanical alterations. For the application to the modelling of Callovo-Oxfordian claystone, microstructural REVs are calibrated to geometrical characteristics of the inclusion that form the microstructure under consideration and to macroscale ex- perimental results of the mechanical behaviour. The calibrated constitutive relation is used in the simulation of gallery excavation processes. These computations give a proof of concept of the doublescale assessment of the hydromechanical behaviour of the excavation damaged zones around galleries in the context of nuclear waste disposal.

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