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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.
101

Influ?ncia da gipsita no surgimento de efloresc?ncia em telhas cer?micas

Monteiro, Celina Margarida de Oliveira Lima 22 May 2009 (has links)
Made available in DSpace on 2014-12-17T14:06:53Z (GMT). No. of bitstreams: 1 CelinaMOLMpdf.pdf: 4472262 bytes, checksum: 97155ddc7b087b9fcfe3f9151a0b8996 (MD5) Previous issue date: 2009-05-22 / The red ceramic industry is recognized as of major importance in Piau? State. The State capital, Teresina, is the greatest producer of this material ( production about 18 million peaces), which is used mainly for masonry sealing blocks. One of the most frequent problems in this kind of products is the efflorescence. This work has the main objective of studying the influence of gypsum addition on non-glazed tiles, by using the local industry production standards. The raw materials were characterized by FRX, DRX, TGA, DTA and AD. Extruded test specimens were made with the addition of 1, 3 and 5% of gypsum in the ceramic paste, burned at 850oC, 950oC and 1050oC and submitted to further technological tests and microestrutural analysis by the scanning electron microscope. In order to accelerate the aging of bodies of evidence, they were immersed in successive water baths and posterior drying. The reference ceramic paste showed tendency to efflorescence formation after drying and consolidated efflorescence after burning, but no affecting the technological results / A ind?stria de cer?mica vermelha ? refer?ncia no Estado do Piau?. Constitui o maior p?lo produtor localizado na capital, Teresina, com produ??o m?dia mensal de 18 milh?es de pe?as, principalmente, de telhas cer?micas. Uma das principais patologias observadas nesse tipo de produto ? o surgimento de efloresc?ncias. Este trabalho visa estudar a influ?ncia da gipsita no surgimento de efloresc?ncias em telhas cer?micas n?o esmaltadas, utilizando padr?es de produ??o da ind?stria local. As mat?rias-primas foram caracterizadas por fluoresc?ncia de raios-X, an?lise mineral?gica por difra??o de raios-X, ensaios t?rmicos e determina??o de sais sol?veis em sulfatos. Foram confeccionados corpos-de-prova por extrus?o, adicionando-se percentuais de 1%, 3% e 5% de gipsita ? massa cer?mica, queimados a 850oC, 950oC e 1050oC. Ap?s sinteriza??o, os corpos-de-prova foram submetidos a ensaios tecnol?gicos e caracteriza??o microestrutural. Para acelerar o envelhecimento, os corpos-de-prova foram submetidos a sucessivos banhos de imers?o em ?gua e posterior secagem. As amostras com adi??o de 1% e 3% de gipsita n?o apresentaram efloresc?ncia ap?s queima. As amostras com adi??o de 1% e 3% de gipsita conduzem a resultados tecnol?gicos satisfat?rios ap?s queima a 950oC, por?m a gipsita n?o reagente aflora ? superf?cie dos corpos-de-prova logo ap?s a primeira imers?o em ?gua.Os corpos-de-prova com 5% de gipsita apresentaram efloresc?ncia de secagem que se consolidou ap?s queima. Os resultados demonstram que o sulfato de c?lcio, oriundo da gipsita, provoca o surgimento de efloresc?ncia
102

Adaptive tiling algorithm based on highly correlated picture regions for the HEVC standard / Algoritmo de tiling adaptativo baseado em regiões altamente correlacionadas de um quadro para o padrão de codificação de vídeos de alta eficiência

Silva, Cauane Blumenberg January 2014 (has links)
Esta dissertação de mestrado propõe um algoritmo adaptativo que é capaz de dinamicamente definir partições tile para quadros intra- e inter-preditos com o objetivo de reduzir o impacto na eficiência de codificação. Tiles são novas ferramentas orientadas ao paralelismo que integram o padrão de codificação de vídeos de alta eficiência (HEVC – High Efficiency Video Coding standard), as quais dividem o quadro em regiões retangulares independentes que podem ser processadas paralelamente. Para viabilizar o paralelismo, os tiles quebram as dependências de codificação através de suas bordas, gerando impactos na eficiência de codificação. Este impacto pode ser ainda maior caso os limites dos tiles dividam regiões altamente correlacionadas do quadro, porque a maior parte das ferramentas de codificação usam informações de contexto durante o processo de codificação. Assim, o algoritmo proposto agrupa as regiões do quadro que são altamente correlacionadas dentro de um mesmo tile para reduzir o impacto na eficiência de codificação que é inerente ao uso de tiles. Para localizar as regiões altamente correlacionadas do quadro de uma maneira inteligente, as características da imagem e também as informações de codificação são analisadas, gerando mapas de particionamento que servem como parâmetro de entrada para o algoritmo. Baseado nesses mapas, o algoritmo localiza as quebras naturais de contexto presentes nos quadros do vídeo e define os limites dos tiles nessas regiões. Dessa maneira, as quebras de dependência causadas pelas bordas dos tiles coincidem com as quebras de contexto naturais do quadro, minimizando as perdas na eficiência de codificação causadas pelo uso dos tiles. O algoritmo proposto é capaz de reduzir mais de 0.4% e mais de 0.5% o impacto na eficiência de codificação causado pelos tiles em quadros intra-preditos e inter-preditos, respectivamente, quando comparado com tiles uniformes. / This Master Thesis proposes an adaptive algorithm that is able to dynamically choose suitable tile partitions for intra- and inter-predicted frames in order to reduce the impact on coding efficiency arising from such partitioning. Tiles are novel parallelismoriented tools that integrate the High Efficiency Video Coding (HEVC) standard, which divide the frame into independent rectangular regions that can be processed in parallel. To enable the parallelism, tiles break the coding dependencies across their boundaries leading to coding efficiency impacts. These impacts can be even higher if tile boundaries split highly correlated picture regions, because most of the coding tools use context information during the encoding process. Hence, the proposed algorithm clusters the highly correlated picture regions inside the same tile to reduce the inherent coding efficiency impact of using tiles. To wisely locate the highly correlated picture regions, image characteristics and encoding information are analyzed, generating partitioning maps that serve as the algorithm input. Based on these maps, the algorithm locates the natural context break of the picture and defines the tile boundaries on these key regions. This way, the dependency breaks caused by the tile boundaries match the natural context breaks of a picture, then minimizing the coding efficiency losses caused by the use of tiles. The proposed adaptive tiling algorithm, in some cases, provides over 0.4% and over 0.5% of BD-rate savings for intra- and inter-predicted frames respectively, when compared to uniform-spaced tiles, an approach which does not consider the picture context to define the tile partitions.
103

Adaptive tiling algorithm based on highly correlated picture regions for the HEVC standard / Algoritmo de tiling adaptativo baseado em regiões altamente correlacionadas de um quadro para o padrão de codificação de vídeos de alta eficiência

Silva, Cauane Blumenberg January 2014 (has links)
Esta dissertação de mestrado propõe um algoritmo adaptativo que é capaz de dinamicamente definir partições tile para quadros intra- e inter-preditos com o objetivo de reduzir o impacto na eficiência de codificação. Tiles são novas ferramentas orientadas ao paralelismo que integram o padrão de codificação de vídeos de alta eficiência (HEVC – High Efficiency Video Coding standard), as quais dividem o quadro em regiões retangulares independentes que podem ser processadas paralelamente. Para viabilizar o paralelismo, os tiles quebram as dependências de codificação através de suas bordas, gerando impactos na eficiência de codificação. Este impacto pode ser ainda maior caso os limites dos tiles dividam regiões altamente correlacionadas do quadro, porque a maior parte das ferramentas de codificação usam informações de contexto durante o processo de codificação. Assim, o algoritmo proposto agrupa as regiões do quadro que são altamente correlacionadas dentro de um mesmo tile para reduzir o impacto na eficiência de codificação que é inerente ao uso de tiles. Para localizar as regiões altamente correlacionadas do quadro de uma maneira inteligente, as características da imagem e também as informações de codificação são analisadas, gerando mapas de particionamento que servem como parâmetro de entrada para o algoritmo. Baseado nesses mapas, o algoritmo localiza as quebras naturais de contexto presentes nos quadros do vídeo e define os limites dos tiles nessas regiões. Dessa maneira, as quebras de dependência causadas pelas bordas dos tiles coincidem com as quebras de contexto naturais do quadro, minimizando as perdas na eficiência de codificação causadas pelo uso dos tiles. O algoritmo proposto é capaz de reduzir mais de 0.4% e mais de 0.5% o impacto na eficiência de codificação causado pelos tiles em quadros intra-preditos e inter-preditos, respectivamente, quando comparado com tiles uniformes. / This Master Thesis proposes an adaptive algorithm that is able to dynamically choose suitable tile partitions for intra- and inter-predicted frames in order to reduce the impact on coding efficiency arising from such partitioning. Tiles are novel parallelismoriented tools that integrate the High Efficiency Video Coding (HEVC) standard, which divide the frame into independent rectangular regions that can be processed in parallel. To enable the parallelism, tiles break the coding dependencies across their boundaries leading to coding efficiency impacts. These impacts can be even higher if tile boundaries split highly correlated picture regions, because most of the coding tools use context information during the encoding process. Hence, the proposed algorithm clusters the highly correlated picture regions inside the same tile to reduce the inherent coding efficiency impact of using tiles. To wisely locate the highly correlated picture regions, image characteristics and encoding information are analyzed, generating partitioning maps that serve as the algorithm input. Based on these maps, the algorithm locates the natural context break of the picture and defines the tile boundaries on these key regions. This way, the dependency breaks caused by the tile boundaries match the natural context breaks of a picture, then minimizing the coding efficiency losses caused by the use of tiles. The proposed adaptive tiling algorithm, in some cases, provides over 0.4% and over 0.5% of BD-rate savings for intra- and inter-predicted frames respectively, when compared to uniform-spaced tiles, an approach which does not consider the picture context to define the tile partitions.
104

Avoiding cracks between terrain segments in a visual terrain database

Holst, Hanna January 2004 (has links)
To be able to run a flight simulator a large area of terrain needs to be visualized. The simulator must update the screen in real-time to make the simulation work well. One way of managing large terrains is to tile the area into quadratic tiles to be able to work with different detailed representations of the terrain at different distances from the user. The tiles need to match with the adjacent tiles in the edge points to avoid cracks. When every tile can have a number of different levels of detail this means that the different levels of detail need to match too. This was previously done by having the same edge points in all levels of detail, giving an unnicessarily large polygon count in the less detailed levels. the method developed in this report uses different versions of borders with their own level of detail, adapting to different detail levels at the adjacent tile, reducing hte number of polygons.
105

Valorisation des fines de lavage de granulats : application à la construction en terre crue / Development of re-use ways for washing aggregates sludges : application to unfired earth construction

Flament, Cédric 12 December 2013 (has links)
Les fines de lavage de carrières sont à l’heure actuelle peu valorisées. Pourtant, leurs caractéristiques physiques font de ces fines une matière première intéressante pour le domaine de la construction. L’objectif de cette thèse est de développer la formulation de produits préfabriqués non porteurs à base de fines de lavage, en considérant ces fines comme de la terre crue. Deux catégories de produits préfabriqués sont visées : un produit dit « lourd » (brique de terre comprimée) et un produit « léger » (carreau). Pour la valorisation en BTC, une étude de compacité par essai Proctor a permis de cibler la teneur en eau de fabrication et la masse volumique sèche à obtenir. Les performances mécaniques des briques ont été améliorées par surcompactage, renforcement granulaire et traitement au liant hydraulique. L’étude de formulation du carreau a associé les fines de lavage et la chènevotte. La consistance des mélanges à l’état frais a été étudiée avec le consistomètre VEBE. Les performances mécaniques en flexion et en compression des mélanges fibrés ont été mesurées. De la chaux et un superplastifiant ont été ajoutés dans la formulation pour satisfaire aux conditions de tenue mécanique. Les deux voies de valorisation ont été validées par mesures des performances physico-mécaniques sur produits fabriqués à l’échelle industrielle. La formulation optimale de BTC valorise près de 80% de fines de lavage et se classe dans la catégorie BTC 40 de la norme expérimentale XP13-901 (brique faiblement capillaire et résistante à la projection en eau). La formulation optimale de carreau se compose de 60% de fines de lavage, et répond aux exigences mécaniques des carreaux de plâtre. / Currently, few re-use ways are developed with clay fines from washing units in quarries. However, these clayey fines represent interesting materials for construction domain. This research work aims to develop non-load bearing precast products and to re-use these fines without thermal treatment as for unfired clay products. Two types of precast products are wished: a “heavy” product (compressed earth brick) and a “light” product (tile hemp-clay).For the CEB re-use way, the level of compaction has to be high. Proctor tests have been done to define the moisture content and dry density to obtain. Mechanical performances of bricks have been increased by overcompaction, granular reinforcement and lime treatment.For the tile re-use way, mixes with quarry fines and hemp have been studied. The behaviour of fresh material has been studied with VEBE consistometer. Flexural and compression strengths have been measured on hardened mixes. Lime and water-reducing agent have been necessary for a good mechanical behaviour.The two re-use ways have been validated by measuring mechanical and physical performances of products manufactured at industrial scale. The optimal mix for CEB includes almost 80% of quarry fines. The CEB is classed in BTC40 category according to experimental standard XP13-901 (brick with a low water absorption level and resistant to water spray). The optimal mix for tile includes 60% of quarry fines and satisfies mechanical requirements for gypsum blocks.
106

Diagnostic, opacité et test de conformité pour des systèmes récursifs / Diagnosis, opacity and conformance testing for recursive tile systems

Chédor, Sébastien 07 January 2014 (has links)
L'une des façons les plus efficace de s'assurer du bon fonctionnement d'un système informatique est de les représenter par des modèles mathématiques. De nombreux travaux ont été réalisés en utilisant des automates finis comme modèles, nous essayons ici d'étendre ces travaux à des modèles infinis. Dans cette thèse, nous nous intéressons à quelques problèmes dans lesquels un système est observé de façon incomplète. Dans ce cas, il est impossible d'accéder à certaines informations internes. La diagnosticabilité d'une propriété donnée consiste à vérifier qu'à l'exécution du système, un observateur sera en mesure de déterminer avec certitude que la propriété est vérifiée par le système. L'opacité consiste, réciproquement, à déterminer qu'un doute existera toujours. Une autre application concerne la génération de cas de test. Une fois encore, on considère qu'un observateur n'accède qu'à une partie des événements se produisant dans le système (en général les entrées et les sorties). À partir d'une spécification, on produit automatiquement des cas de test, qui ont pour but de détecter des non-conformités (elles même formalisées de façon précise). Ces trois problèmes ont été étudiés pour des modèles finis. Dans cette thèse, nous étendons leur étude aux modèles récursifs, pour cela nous avons introduit notre propre modèle, les RTS, qui sont une généralisation des automates à pile, et d'autres modèles de la récursivité. Nous adaptons ensuite les techniques utilisées sur des modèles finis, qui servent à résoudre les problèmes qui nous intéressent. / An effective way to ensure the proper functioning of a computer system is to represent it by using mathematical models . Many studies have been conducted using finite automata as models, in this thesis we try to extend these works to infinite models. We focus on three problems in which a system is partially observed. In this case, it is impossible to access certain internal informations. Diagnosability of a given property consist in checking, that, during the execution of the system, an observer will be able to determine with certainty that the property is verified by the system. Conversely, the opacity consists in determining if a doubt will always exist. Another application is the generation of test cases. Once again, we consider that an observer accesses only some events of the system (typically the inputs and outputs): from a specification, we automatically generate test cases, which are designed to detect non-conformance. These three problems have been studied for finite models. In this thesis, we extend their study to recursive models. For this purpose, we have introduced a new model, the RTS, which are a generalization of pushdown automata and other models of recursion. In order to solve problems of interest, we adapt the techniques used in finite models.
107

Adaptive tiling algorithm based on highly correlated picture regions for the HEVC standard / Algoritmo de tiling adaptativo baseado em regiões altamente correlacionadas de um quadro para o padrão de codificação de vídeos de alta eficiência

Silva, Cauane Blumenberg January 2014 (has links)
Esta dissertação de mestrado propõe um algoritmo adaptativo que é capaz de dinamicamente definir partições tile para quadros intra- e inter-preditos com o objetivo de reduzir o impacto na eficiência de codificação. Tiles são novas ferramentas orientadas ao paralelismo que integram o padrão de codificação de vídeos de alta eficiência (HEVC – High Efficiency Video Coding standard), as quais dividem o quadro em regiões retangulares independentes que podem ser processadas paralelamente. Para viabilizar o paralelismo, os tiles quebram as dependências de codificação através de suas bordas, gerando impactos na eficiência de codificação. Este impacto pode ser ainda maior caso os limites dos tiles dividam regiões altamente correlacionadas do quadro, porque a maior parte das ferramentas de codificação usam informações de contexto durante o processo de codificação. Assim, o algoritmo proposto agrupa as regiões do quadro que são altamente correlacionadas dentro de um mesmo tile para reduzir o impacto na eficiência de codificação que é inerente ao uso de tiles. Para localizar as regiões altamente correlacionadas do quadro de uma maneira inteligente, as características da imagem e também as informações de codificação são analisadas, gerando mapas de particionamento que servem como parâmetro de entrada para o algoritmo. Baseado nesses mapas, o algoritmo localiza as quebras naturais de contexto presentes nos quadros do vídeo e define os limites dos tiles nessas regiões. Dessa maneira, as quebras de dependência causadas pelas bordas dos tiles coincidem com as quebras de contexto naturais do quadro, minimizando as perdas na eficiência de codificação causadas pelo uso dos tiles. O algoritmo proposto é capaz de reduzir mais de 0.4% e mais de 0.5% o impacto na eficiência de codificação causado pelos tiles em quadros intra-preditos e inter-preditos, respectivamente, quando comparado com tiles uniformes. / This Master Thesis proposes an adaptive algorithm that is able to dynamically choose suitable tile partitions for intra- and inter-predicted frames in order to reduce the impact on coding efficiency arising from such partitioning. Tiles are novel parallelismoriented tools that integrate the High Efficiency Video Coding (HEVC) standard, which divide the frame into independent rectangular regions that can be processed in parallel. To enable the parallelism, tiles break the coding dependencies across their boundaries leading to coding efficiency impacts. These impacts can be even higher if tile boundaries split highly correlated picture regions, because most of the coding tools use context information during the encoding process. Hence, the proposed algorithm clusters the highly correlated picture regions inside the same tile to reduce the inherent coding efficiency impact of using tiles. To wisely locate the highly correlated picture regions, image characteristics and encoding information are analyzed, generating partitioning maps that serve as the algorithm input. Based on these maps, the algorithm locates the natural context break of the picture and defines the tile boundaries on these key regions. This way, the dependency breaks caused by the tile boundaries match the natural context breaks of a picture, then minimizing the coding efficiency losses caused by the use of tiles. The proposed adaptive tiling algorithm, in some cases, provides over 0.4% and over 0.5% of BD-rate savings for intra- and inter-predicted frames respectively, when compared to uniform-spaced tiles, an approach which does not consider the picture context to define the tile partitions.
108

Light Performance Comparison betweenForward, Deferred and Tile-basedforward rendering

Poliakov, Vladislav January 2020 (has links)
Background. In this experiment forward, deferred and tile-based forward rendering techniques are implemented to research about the light-rendering performance of these rendering techniques. Nowadays most games and programs contains a graphical content and this graphical content is done by using different kind of rendering operations. These rendering operations is being developed and optimized by graphic programmers in order to show better performance. Forward rendering is the standard technique that pushes the geometry data through the whole rendering pipeline to build up the final image. Deferred rendering on the other hand is divided into two passes where the first pass rasterizes the geometry data into g-buffers and the second pass, also called lighting pass, uses the data from g-buffers and rasterizes the lightsources to build up the final image. Next rendering technique is tile-based forward rendering, is also divided into two passes. The first pass creates a frustum grid and performs light culling. The second pass rasterizes all the geometry data to the screen as the standard forward rendering technique. Objectives. The objective is to implement three rendering techniques in order to find the optimal technique for light-rendering in different environments. When the implementation process is done, analyze the result from tests to answer the research questions and come to a conclusion. Methods. The problem was answered by using method "Implementation and Experimentation". A render engine with three different rendering techniques was implemented using C++ and OpenGL API. The tests were implemented in the render engine and the duration of each test was five minutes. The data from the tests was used to create diagrams for result evaluation. Results. The results showed that standard forward rendering was stronger than tile based forward rendering and deferred rendering with few lights in the scene.When the light amount became large deferred rendering showed the best light performance results. Tile-based forward rendering wasn’t that strong as expected and the reason can possibly be the implementation method, since different culling procedures were performed on the CPU-side. During the tests of tile-based forward rendering there were 4 tiles used in the frustum grid since this amount showed highest performance compared to other tile-configurations. Conclusions. After all this research a conclusion was formed as following, in environments with limited amount of lightsources the optimal rendering technique was the standard forward rendering. In environments with large amount of lightsources deferred rendering should be used. If tile-based forward rendering is used, then it should be used with 4 tiles in the frustum grid. The hypothesis of this study wasn’t fully confirmed since only the suggestion with limited amount of lights were confirmed, the other parts were disproven. The tile-based forward rendering wasn’t strong enough and the reason for this is possibly that the implementation was on the CPU-side.
109

Bytový dům / Apartment house

Vavřincová, Jana January 2016 (has links)
The subjekt of my thesis is a project of a new apartment house. The building with 16 residential units and a garage for four cars has three aboveground floors and a flat roof. The walls will be made from clay blocks HELUZ. The project of the building is in accordance with the development plan of Příbram. Further emphasis is on layout, architectural, fire and thermal aspects of the individual structures. The thesis "Apartment House" has been prepared in the form of project documentation containing all terms required by regulations.
110

Fast High-order Integral Equation Solvers for Acoustic and Electromagnetic Scattering Problems

Alharthi, Noha 18 November 2019 (has links)
Acoustic and electromagnetic scattering from arbitrarily shaped structures can be numerically characterized by solving various surface integral equations (SIEs). One of the most effective techniques to solve SIEs is the Nyström method. Compared to other existing methods,the Nyström method is easier to implement especially when the geometrical discretization is non-conforming and higher-order representations of the geometry and unknowns are desired. However,singularities of the Green’s function are more difficult to”manage”since they are not ”smoothened” through the use of a testing function. This dissertation describes purely numerical schemes to account for different orders of singularities that appear in acoustic and electromagnetic SIEs when they are solved by a high-order Nyström method utilizing a mesh of curved discretization elements. These schemes make use of two sets of basis functions to smoothen singular integrals: the grid robust high-order Lagrange and the high-order Silvester-Lagrange interpolation basis functions. Numerical results comparing the convergence of two schemes are presented. Moreover, an extremely scalable implementation of fast multipole method (FMM) is developed to efficiently (and iteratively) solve the linear system resulting from the discretization of the acoustic SIEs by the Nyström method. The implementation results in O(N log N) complexity for high-frequency scattering problems. This FMM-accelerated solver can handle N =2 billion on a 200,000-core Cray XC40 with 85% strong scaling efficiency. Iterative solvers are often ineffective for ill-conditioned problems. Thus, a fast direct (LU)solver,which makes use of low-rank matrix approximations,is also developed. This solver relies on tile low rank (TLR) data compression format, as implemented in the hierarchical computations on many corearchitectures (HiCMA) library. This requires to taskify the underlying SIE kernels to expose fine-grained computations. The resulting asynchronous execution permit to weaken the artifactual synchronization points,while mitigating the overhead of data motion. We compare the obtained performance results of our TLRLU factorization against the state-of-the-art dense factorizations on shared memory systems. We achieve up to a fourfold performance speedup on a 3D acoustic problem with up to 150 K unknowns in double complex precision arithmetics.

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