Orientador: Pablo Siqueira Meirelles / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-26T13:45:42Z (GMT). No. of bitstreams: 1 Alvarez-Jacobo_JustoEmilio_D.pdf: 7664743 bytes, checksum: 72e7ab67912a544a9178da02711121d9 (MD5) Previous issue date: 2013 / Resumo: Este trabalho apresenta o estudo e desenvolvimento de um Sistema de Percepção baseado na utilização de sensores telemétricos tipo LIDAR. Uma plataforma de escaneamento a laser em três dimensões LMS-3D é construída a fim da navegação autônoma de robôs. A área navegável é obtida a partir de mapas telemétricos, caracterizados com algoritmos de grades de ocupação (GO) (em duas dimensões com a terceira colorida e 3D) e com o cálculo de gradientes vetoriais. Dois tipos de áreas navegáveis são caracterizadas: (i) área de navegação primária representada por uma área livre dentro da GO; e (ii) área de navegação continua representada pela soma das áreas continuas e gradientes classificados com um determinado limiar. Este limiar indica se uma área é passível de navegação considerando as características do robô. A proposta foi avaliada experimentalmente em ambiente real, contemplou a detecção de obstáculos e a identificação de descontinuidades / Abstract: This thesis was proposed to demonstrate the study and development of a Perception System based on the utilization of a LIDAR telemetric sensors. It was proposed to create a LMS-3D three dimension laser scanning platform, in an attempt to promote the Autonomous Robot Navigation. The scanned area was obtained based on telemetric maps, which was characterized with Occupancy Grid algorithms (OG) (in two dimensions with the third colored and 3D) and Vector Gradients calculation. Two different navigation areas were characterized: (i) primary area of navigation, that represents the free area inside a OG, and (ii) continuous navigation area, that represents the navigated area composed by the sum of continuous areas and the gradients classified by a determined threshold, which indicates the possible navigated area, based on the robot characteristics. The proposition of this thesis was evaluated in a real environment and was able to identify the obstacles detection and also the discontinuance / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica

This thesis explores the balance between visual quality and the performance of a 3D object for computer games. Additionally, it aims to help new 3D artists to create assets that are both visually adequate and optimized for real-time rendering. It further investigates the differences in the judgement of the visual quality of thosethat know computer graphics, and thosenot familiar with it. Many explanations of 3D art optimization are often highly technical and challenging for graphic artists to grasp. Additionally, they regularly neglect the effects of optimization to the visual quality of the assets. By testing several 3D assets to measure their render time while using a survey to gather their visual assessments, it was discovered that 3D game art is very contextual. No definite or straightforward way was identified to find the balance between art quality and performance universally. Neither when it comes to performance nor visuals. However, some interesting findings regarding the judgment of visual quality were observed and presented. / Den här uppsatsen utforskar balansen mellan visuell kvalitéoch prestanda i 3D modeller för spel. Vidare eftersträvar den att utgöra ett stöd för nya 3D-modelleingskonstnärer för att skapa modeller som är både visuellt adekvata och optimerade för att renderas i realtid. Dessutom undersöks skillnaden mellan omdömet av den visuella kvalitén mellan de som är bekanta med 3D datorgrafik och de som inte är det. Många förklaringar gällande optimering av 3D grafik är högst tekniska och utgör en utmaning för grafiker att förståsig på och försummar dessutom ofta effekten av hur optimering påverkar resultatet rent visuallet. Genom att testa ett flertal 3D modeller, mäta tiden det tar för dem att renderas, samt omdömen gällande visuella intryck, drogs slutsatsen att bedömning av 3D modellering för spel är väldigt kontextuell. Inget definitivt och enkelt sätt att hitta balansen mellan visuella kvalitén upptäcktes. Varken gällande prestanda eller visuell kvalité. Däremot gjordes några intressanta upptäckter angående bedömningen av den visuella kvalitén som observerades och presenterades.

La planification chirurgicale repose sur l’anatomie du patient, et repose souvent sur l’analyse d’images médicales acquises avant la chirurgie. En particulier, c’est le cas pour les interventions de chirurgie pelvienne en pédiatrie, pour de nombreuses pathologies telles que des tumeurs et des malformations. Dans cette zone anatomique, en raison de sa forte vascularisation et innervation, une bonne planification chirurgicale est extrêmement importante pour éviter des lésions fonctionnelles des organes du patient, qui pourraient nuire a sa qualité de vie. En pratique clinique, la procédure standard repose sur l’analyse visuelle, coupe par coupe, des images de la région pelvienne. Cette tâche, même si elle est facilement accomplie par des radiologues experts, est très complexe et fastidieuse pour les chirurgiens, en raison de la complexité et de la variabilité des structures anatomiques et, par conséquent, de leurs images. De plus, en raison des variations anatomiques selon l’age du patient, toutes ces difficultés sont accentuées en pédiatrie et une compréhension anatomique claire est encore plus importante que pour les adultes. Pour ces raisons, il est important et utile d’être capable de fournir aux chirurgiens des modèles anatomiques 3D spécifiques aux patients, obtenus par traitement et analyse des images IRM.Dans cette thèse, nous proposons un ensemble de méthodes de segmentation d’images IRM de patients pédiatriques. Nous nous concentrons sur trois structures pelviennes importantes : les os du bassin, les vaisseaux sanguins et la vessie. Pour les os, nous proposons une méthode semi-automatique comportant une première étape de recalage de modèles osseux puis une étape de segmentation fine par modèles déformables. La principale contribution de la méthode proposée est l’introduction d’un ensemble de modèles osseux pour différentes tranches d’age, ce qui permet de prendre en compte la variabilité des os pendant la croissance. Pour les vaisseaux, nous proposons une méthode par patchs, apprentissage profond et transfert d’apprentissage, donc ne nécessitant que peu de donnes d’apprentissage. La principale contribution de ce travail est la conception d’une procédure semi-automatique pour l’extraction des patchs, qui permet a l’utilisateur de se focaliser uniquement sur les vaisseaux d’intérêt; et pour la planification chirurgicale. Pour la segmentation de la vessie, nous proposons d’utiliser une approche par modèles déformables, particulièrement robuste aux hétérogénéités de l’image et aux effets de volume partiel, souvent présents dans les images IRM pédiatriques. Toutes les méthodes proposées sont intégrées dans une plateforme logicielle libre pour le traitement d’images médicales, donnant aux chirurgiens des outils performants avec des interfacesutilisateur faciles a utiliser. De plus, nous mettons en place une stratégie de traitement et de portabilité pour la visualisation des modèles 3D du patient, permettant aux chirurgiens de générer, visualiser et partager ces modèles au sein de l’hôpital. En conclusion, les résultats obtenus avec les méthodes proposées sont quantitativement et qualitativement évalués de manière très positive par des chirurgiens pédiatriques, démontrant leurs potentialités pour l’utilisation en pratique clinique dans des procédures de planification chirurgicale. / Surgical planning relies on the patient’s anatomy, and it is often based on medical images acquired before the surgery. This is in particular the case for pelvic surgery on children, for various indications such as malformations or tumors. In this particular anatomical region, due to its high vascularization and innervation, a good surgical planning is extremely important to avoid potential functional damages to the patient’s organs that could strongly affect their quality of life. In clinical practice the standard procedure is still to visually analyze, slice by slice, the images of the pelvic region. This task, even if quite easily performed by the expert radiologists, is difficult and tedious for the surgeons due to the complexity and variability of the anatomical structures and hence their images. Moreover, due to specific anatomy depending on the age of the patient, all the difficulties of the surgical planning are emphasized in the case of children, and a clear anatomical understanding is even more important than for the adults. For these reasons, it is very important and challenging to provide the surgeons with patient-specific 3D reconstructions, obtained from the segmentation of MRI images. In this work we propose a set of segmentation tools for pelvic MRI images of pediatric patients. In particular, we focus on three important pelvic structures: the pelvic bones, the pelvic vessels and the urinary bladder. For pelvic bones, we propose a semi-automatic approach based on template registration and deformable models. The main contribution of the proposed method is the introduction of a set of bones templates for different age ranges, which allows us to take into account the bones variability during growth. For vessels segmentation, we propose a patch-based deep learning approach using transfer learning, thus requiring few training data. The main contribution of this work is the design of a semi-automatic strategy for patches extraction, which allows the user to focus only on the vessels of interest for surgical planning. For bladder segmentation, we propose to use a deformable model approach that is particularly robust to image inhomogeneities and partial volume effects, which are often present in pediatric MRI images. All the developed segmentation methods are integrated in an open-source platform for medical imaging, delivering powerful tools and user-friendly GUIs to the surgeons. Furthermore, we set up a processing and portability workflow for visualization of the 3D patient specific models, allowing surgeons to generate, visualize and share within the hospital the patient specific 3D models. Finally, the results obtained with the proposed methods are quantitatively and qualitatively evaluated by pediatric surgeons, which demonstrates their potentials for clinical use in surgical planning procedures.

Salt tectonics has important implications for hydrocarbon exploration in saltbearing basins since salt deformation can directly or indirectly form hydrocarbon traps, influence hydrocarbon migration, and can control deepwater depositional systems. In various basins around the globe, extensive research has been conducted on initiation of salt mobilization, subsequent deformation, and eventual cessation, mostly from subsurface two-dimensional (2D) sections. However, 3D seismic data has dominated the petroleum industry for the last 30 years. Despite the plethora of 3D seismic data acquired in salt-bearing basins, there has been hardly any published work on the 3D geometries of complex salt bodies. 3D salt mapping in the subsurface can reveal true distribution of salt bodies and their detailed intricacies of geometrical variations, aiding in the overall salt system interpretation. Using a large 3D seismic survey (3,350 km2), this study presents the first 3D salt mapping in the Gulf of Mexico, demonstrating how 3D visualization of the entire Louann Salt system within the Middle Jurassic to presentday stratigraphy can improve interpretation of salt feeder geometries, allochthonous salt canopies, initial salt distribution, and salt weld locations in the study area.

Realistic modeling of a 3D environment has grown in popularity due to the increasing realm of practical applications. Whether for practical navigation purposes, entertainment value, or architectural standardization, the ability to determine the dimensions of a room is becoming more and more important. One of the trickier, but critical, features within any multistory environment is the staircase. Staircases are difficult to model because of their uneven surface and various depth aspects. Coupling this need is a variety of ways to reach this goal. Unfortunately, many such methods rely upon specialized sensory equipment, multiple calibrated cameras, or other such impractical setups. Here, we propose a simpler approach. This paper outlines a method for extracting the slope dimensions of a staircase using a single monocular image. By relying on only a single image, we negate the need for extraneous accessories and glean as much information from common pictures. We do not hope to achieve the high level of accuracy seen from laser scanning methods but seek to produce a viable result that can both be helpful for current applications and serve as a building block that contributes to later development. When constructing our pipeline, we take into account several options. Each step can be achieved with different techniques which we evaluate and compare on either a qualitative or quantitative level. This leads to our final result which can accurately determine the slope of a staircase with an error rate of 31.1%. With a small amount of previous knowledge or preprocessing, this drops down to an average of 18.7% Overall, we deem this an acceptable and optimal result given the limited information and processing resources which the program was allowed to utilize.

Orientador: Cesar Augusto Moreira / Resumo: Uma barragem de rejeitos é constituída por uma barreira física, cuja função é a acumulação de produtos residuais do processo industrial de beneficiamento mineiro. Os métodos de projeto para barragens de rejeitos diferem das barragens de retenção de água pela construção do barramento em diferentes etapas. Deste modo, os problemas de estabilidade em uma barragem são de grande importância, principalmente quando se trata de barragens construídas para armazenamento destes rejeitos de mineração, uma vez que a possibilidade de falhas não apenas ameaça a segurança das pessoas e da propriedade industrial, mas também pode causar impactos ambientais substanciais. No Estado de Minas Gerais, aproximadamente 30 km a sudoeste do município de Caldas, está localizada a Mina Osamu Utsumi de responsabilidade das Indústrias Nucleares do Brasil (INB), a qual tem um sistema para contenção de rejeitos provenientes da exploração e processamento de urânio, atualmente desativado. O Sistema consiste em uma barragem de rocha e terra a qual apresenta a existência de surgências no maciço rochoso à jusante do barramento, cujo fluxo ocorre em sistema fraturado. O objetivo do trabalho é reconhecer possíveis zonas de fluxo no interior e na base da barragem por meio de um conjunto de ensaios geofísicos de eletrorresistividade adquiridos com a técnica de tomografia elétrica através de modelos de inversão 2D e modelamento 3D. Foram adquiridas 5 linhas de tomografia elétrica com espaçamento entre eletrodos de 6 m... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: A tailings dam is constituted by a barrier, whose function is the accumulation of residual products from the mining beneficiation industrial process. Project methods for tailings dams differ from water retention dams by the construction of the dam in different stages. Thus, the stability problems in a dam are of great importance, especially when it comes to dams built for the storage of these mining waste, since the possibility of failures not only threatens the safety of people and industrial property, but also cause negative and substantial effects to the local environment. The Osamu Utsumi uranium mine, administrated by the state company Industrias Nucleares do Brasil (INB), is located 30 km southwest of Caldas, in the State of Minas Gerais, and its contention system of tailings, generated by the exploration and processing of uranium ore, is currently out of operation. The system is composed of a rock-soil dam, which presents the existence of water upwellings downstream in the bedrock, with water flux confined in fractures. This research aims the recognition of possible flux zones into the base of the dam through geophysical surveys applying DC Resistivity, in addition to Electrical Resistivity Tomography technique in the generation of 2D inversion models and 3D modeling. The acquisition was composed of five lines of electrical resistivity tomography with 6 m of spacing between electrodes, using Schlumberger array. The results are presented by 2D and 3D geophysical models ... (Complete abstract click electronic access below) / Mestre

Cette thèse est centrée sur l'affichage et la manipulation en temps interactif au sein d'un navigateur Internet de modèles 3D issus de Systèmes d'Informations Géographiques (SIG). Ses principales contributions sont la visualisation de terrains 3D haute résolution, la simplification de maillages irréguliers sur GPU, et la création d'une nouvelle API navigateur permettant de réaliser des traitements lourds et efficaces (parallélisme GP/GPU) sans compromettre la sécurité. La première approche proposée pour la visualisation de modèles de terrain s'appuie sur les récents efforts des navigateurs pour devenir une plateforme versatile. Grâce aux nouvelles API 3D sans plugin, nous avons pu créer un client de visualisation de terrains "streamés" à travers HTTP. Celui-ci s'intègre parfaitement dans les écosystèmes Web-SIG actuels (desktop et mobile) par l'utilisation des protocoles standards du domaine (fournis par l'OGC, Open Geospatial Consortium). Ce prototype s'inscrit dans le cadre des partenariats industriels entre ATOS Worldline et ses clients SIG, et notamment l'IGN (institut national de l'information géographique et forestière) avec le Géoportail (http://www.geoportail.gouv.fr) et ses API cartographiques. La 3D dans les navigateurs possède ses propres défis, qui sont différents de ce que l'on connaît des applications lourdes : aux problèmes de transfert de données s'ajoutent les restrictions et contraintes du JavaScript. Ces contraintes, détaillées dans le paragraphe suivant, nous ont poussé à repenser les algorithmes de référence de visualisation de terrain afin de prendre en compte les spécificités dues aux navigateurs. Ainsi, nous avons su profiter de la latence du réseau pour gérer dynamiquement les liaisons entre les parties du maillage sans impacter significativement la vitesse du rendu. Au-delà de la visualisation 3D, et bien que le langage JavaScript autorise le parallélisme de tâches, le parallélisme de données reste quasi inexistant au sein des navigateurs Web. Ce constat, couplé à la faiblesse de traitement du JavaScript, constituait un frein majeur dans notre objectif de définir une plateforme SIG complète et performante intégrée au navigateur. C'est pour cette raison que nous avons conçu et développé, à travers les WebCLWorkers, une API Web de calcul GP/GPU haute performance répondant aux critères de simplicité et de sécurité inhérents au Web. Contrairement à l'existant, qui se base sur des codes déjà précompilés ou met de côté les performances, nous avons tenté de trouver le bon compromis pour avoir un langage proche du script mais sécurisé et performant, en utilisant les API OpenCL comme moteur d'exécution. Notre proposition d'API a intéressé la fondation Mozilla qui nous a ensuite demandé de participer à l'élaboration du standard WebCL dans la cadre du groupe Khronos, (aux côtés de Mozilla mais aussi de Samsung, Nokia, Google, AMD, etc.). Grâce aux nouvelles ressources de calcul ainsi obtenues, nous avons alors proposé un algorithme de simplification parallèle de maillages irréguliers. Alors que l'état de l'art repose essentiellement sur des grilles régulières pour le parallélisme (hors Web) ou sur la simplification via clusterisation et kd-tree, aucune solution ne permettait d'avoir à la fois une simplification parallèle et des modèles intermédiaires utilisables pour la visualisation progressive en utilisant des grilles irrégulières. Notre solution repose sur un algorithme en trois étapes utilisant des priorités implicites et des minima locaux afin de réaliser la simplification, et dont le degré de parallélisme est linéairement lié au nombre de points et de triangles du maillage à traiter [etc...]GP/GPU / This thesis focuses on displaying and manipulating 3D models from Geographic Information Systems (GIS) in interactive time directly in a web browser. Its main contributions are the visualization of high resolution 3D terrains, the simplification of irregular meshes on the GPU, and the creation of a new API for performing heavy and effective computing in the browser (parallelism GP/GPU) without compromising safety. The first approach proposed for the visualization of terrain models is built on recent browsers efforts to become a versatile platform. With the new 3D pluginless APIs, we have created a visualization client for terrain models “streamed” through HTTP. It fits perfectly into the current Web-GIS ecosystem (desktop and mobile) by the use of the standard protocols provided by OGC Open Geospatial Consortium. This prototype is part of an industrial partnership between ATOS Wordline and its GIS customer, and particularly the IGN (French National Geographic Institute) with the Geoportail application (http://www.geoportail.gouv.fr) and its mapping APIs. The 3D embedded in browsers brings its own challenges which are different from what we know in heavy applications: restrictions and constraints from JavaScript but also problems of data transfer. These constraints, detailed in the next paragraph, led us to rethink the standard algorithms for 3D visualization to take into account the browser specificities. Thus, we have taken advantage of network latency to dynamically manage the connections between the different parts of the mesh without significantly impacting the rendering speed. Beyond 3D visualization, and even if the JavaScript language allows task parallelism, data parallelism remains absent from Web browsers. This observation, added to the slowness of JavaScript processing, constituted a major obstacle in our goal to define a complete and powerful GIS platform integrated in the browser. That is why we have designed and developed the WebCLWorkers, a GP/GPU Web API for high performance computing that meets the criteria of simplicity and security inherent to the Web. We tried to find a trade-off for a language close to the script but secure and efficient, based on the OpenCL API at runtime. This approach is opposite to the existing ones, which are either based on precompiled code or disregard performances. Our API proposal interested the Mozilla Foundation which asked us to participate in the development of the WebCL standard by integrating the Khronos Group (Mozilla, Samsung, Nokia, Google, AMD, and so on). Exploiting these new computing resources, we then suggested an algorithm for parallel simplification of irregular meshes. While the state of the art was mainly based on regular grids for parallelism (and did not take into account Web browsers restrictions) or on simplification and kd-tree clustering, no solution could allow both parallel simplification and progressive visualization using irregular grids. Our solution is based on a three-step algorithm using implicit priorities and local minima to achieve simplification, and its degree of parallelism is linearly related to the number of points and triangles in the mesh to process. We have proposed in the thesis an innovative approach for 3D WebGIS pluglinless visualization, offering tools that bring to the browser a comfortable GP/GPU computing power, and designing a method for irregular meshes parallel simplification allowing to visualize level of details directly in Web browsers. Based on these initial results, it becomes possible to carry all the rich functionalities of desktop GIS clients to Web browsers, on PC as well as mobile phones and tablets

This thesis investigates how the color red can potentially affect the player’s perception of horror game environments. The test was conducted by asking participants to play through a horror level made in Unreal Engine 4 which used realistic-looking assets. The study was performed using a mixed methodology of A/B/C testing with surveys and interviews to gather the data. The A, B, and C versions of the test used the same game-level in all versions however the color of the lighting was different in all of them. Version A used white lights, version B used red lights, and version C used red flickering lights. The results revealed that the players found the version with the white lights to be the scariest and the version with the flickering lights to be the second scariest. This was most likely due to the order in which the players played the levels, the version with white being the first that the players played. The players indicated that the realistic colors in version A added to the sense of immersion, whereas the continuous red lights in version B were perceived by some players as overdone or unnatural and would have been better suited for localized areas associated with supernatural elements. The flickering lights were well received by players and associated with a higher potential for danger and jump scares

As virtual reality and interaction possibilities in game technology evolve and become more user-friendly, accessible and cheaper, this technology suddenly gets useful in occupational areas that traditionally have not used them, one being urban planning. By using a game engine and a virtual neighborhood that utilizes procedural generation the user has the option of having a cost-effective, replicable environment with great control from the user.  According to the Broken Windows Theory small differences in appearance can have a big impact on how an urban neighborhood will be perceived. Therefore it would be interesting to investigate how the perception of street scenes is affected by the different aesthetic properties of dirt, graffiti, broken windows, building height and greenery (trees and bushes). By implementing a virtual neighborhood that utilizes procedural generation the basic structure of the neighborhood can stay the same, while separately adjusting the specific properties that are being evaluated. Through surveys and interviews the results show that every one of the chosen properties are very significant except for building height. Generally the more trees that were present, the more safe the neighborhood felt, and the order of significance of dirt, graffiti and broken windows differed between the two evaluation methods. / Då virtual reality och interaktionsmöjligheterna inom spelteknologi utvecklas och blir mer användarvänliga, mer tillgängliga och billigare, blir denna teknik plötsligt användbar inom yrkesområden som traditionellt sett inte har använt dem, där ett exempel är stadsplanering. Genom att använda en spelmotor och en virtuell stadsdel som utnyttjar procedural generation får användaren en kostnadseffektiv, replikerbar miljö med stor kontroll från användaren. Enligt Broken Windows Theory så kan små skillnader i utseende ha en stor inverkan på hur en stadsdel kommer att uppfattas. Därför vore det intressant att undersöka hur synen på virtuella gatscener påverkas av olika estetiska egenskaper som smuts, graffiti, trasiga fönster, bygghöjd, och grönska (träd och buskar). Genom att implementera en virtuell stadsdel som utnyttjar procedural generation kan grundstrukturen vara densamma, medan man separat justerar de specifika egenskaperna som ska utvärderas. Genom enkäter och intervjuer visar resultaten att var och en av de valda egenskaperna är mycket betydande, med undantaget för byggnadshöjd. Generellt så kändes stadsdelen mer säker desto mer träd som fanns, och ordningen av signifikansen för smuts, graffiti, och trasiga fönster skiljde sig mellan enkäterna och intervjuerna.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18966号 / 工博第4008号 / 新制||工||1617(附属図書館) / 31917 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 小池 克明, 教授 石田 毅, 准教授 水戸 義忠 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM