Дисертації з теми "Modèle voxel"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Modèle voxel.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-39 дисертацій для дослідження на тему "Modèle voxel".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Parvathaneni, Keerthi Krishna. "Characterization and multiscale modeling of textile reinforced composite materials considering manufacturing defects." Electronic Thesis or Diss., Ecole nationale supérieure Mines-Télécom Lille Douai, 2020. http://www.theses.fr/2020MTLD0016.
Анотація:
L’influence des porosités induites par les procédés de fabrication sur les propriétés mécaniques des composites textiles a été étudiée à la fois par caractérisation expérimentale et par modélisation multi-échelle. En particulier, les porosités ont été caractérisés en termes de fraction volumique, taille, forme et distribution, et les effets de chaque caractéristique sur les propriétés mécaniques des composites textiles ont été analysés. De nombreuses plaques de composites textiles ont été fabriquées par le procédé Resin Transfer Molding (RTM). Ainsi, un renfort textile en verre interlock 3D a été imprégné par une résine époxy injectée sous une pression constante pour générer différents types de porosités. Des essais mécaniques ont été réalisés pour examiner la dépendance du module et de la résistance en traction des composites par rapport au taux de porosité total, intra-toron et inter-toron et également par rapport aux caractéristiques géométriques des porosités. Des analyses au microscope électronique ont été effectuées pour obtenir des informations locales sur les fibres (diamètre et distribution) et les porosités intra-toron (rayon, rapport d’aspect et distribution). A partir de ces résultats, un nouvel algorithme a été développé pour générer le Volume Elémentaire Représentatif (VER) qui est statistiquement équivalent au composite contenant les porosités. De plus, l’effet de la morphologie, du diamètre et de la distribution spatiale des porosités (homogène, aléatoire et concentré) sur les propriétés homogénéisées des torons a également été étudié par la méthode des éléments finis. La tomographie par rayons X a été utilisée pour extraire la géométrie méso-échelle réelle en trois dimensions et les porosités intra-toron. Ensuite, ces données ont été utilisées pour créer un modèle numérique à l’échelle mésoscopique (VER) et prédire les propriétés élastiques des composites avec porosités. Une étude paramétrique utilisant une méthode numérique multi-échelle a été effectuée pour étudier l’effet de chaque caractéristique des porosités, c.-à-d. le taux volumique, la taille, la forme, la distribution et la localisation sur les propriétés élastiques de composites. Ainsi, la méthode multi-échelle proposée permet d’établir une corrélation entre les porosités à différentes échelles et les propriétés mécaniques des composites textilesThe influence of void-type manufacturing defects on the mechanical properties of textile composites was investigated both by experimental characterization and by multiscale modeling. In particular, voids characteristics such as not only void volume fraction but also its size, shape, and distribution have been characterized for textile composites and their effect on the mechanical properties have been analyzed. Several textile composite plates were fabricated by the resin transfer molding (RTM) process where 3D interlock glass textile reinforcement was impregnated by epoxy resin under a constant injection pressure to generate different types of voids. A series of mechanical tests were performed to examine the dependency of tensile modulus and strength of composites on the total void volume fraction, intra & inter-yarn void volume fraction, and their geometrical characteristics. Microscopy observations were performed to obtain the local information about fibers (diameter and distribution), and intra-yarn voids (radius, aspect ratio and distribution). Based on these results, a novel algorithm was proposed to generate the statistically equivalent representative volume element (RVE) containing voids. Moreover, the effect of void morphology, diameter and spatial distribution (homogeneous, random and clustering) on the homogenized properties of the yarns was also investigated by the finite element method. X-ray micro-computed tomography was employed to extract the real meso-scale geometry and inter-yarn voids. Subsequently, this data was utilized to create a numerical model at meso-scale RVE and used to predict the elastic properties of composites containing voids. A parametric study using a multiscale numerical method was proposed to investigate the effect of each void characteristic, i.e. volume fraction, size, shape, distribution, and location on the elastic properties of composites. Thus, the proposed multiscale method allows establishing a correlation between the void defects at different scales and the mechanical properties of textile composites
2
Feron, Maryse. "Étude des mécanismes neurophysiologiques de l'instabilité posturale dans la sclérose latérale amyotrophique à partir d'un modèle biomécanique de l'initiation de la marche." Thesis, Paris 10, 2016. http://www.theses.fr/2016PA100187/document.
Анотація:
L'instabilité posturale est souvent observée chez les patients atteints de la sclérose latérale amyotrophique (SLA). Cependant, les mécanismes neuronaux impliqués dans cette instabilité posturale demeurent largement inconnus. Comparés aux patients SLA sans instabilité postural, les patients atteints de SLA avec instabilité posturale présentent des APA altérés avec un déplacement postérieur du centre de pression du pied diminué (CP) et une durée des APA augmentée, la longueur et la vitesse du premier pas sont réduites, enfin, le contrôle postural dynamique est déficitaire avec une diminution spectaculaire de l'indice de freinage. A l'inverse, nous n’observons aucune modification des phases d’anticipation et d’exécution du pas chez les patients SLA sans instabilité posturale comparés aux sujets témoins. Le faible recul du CP au cours de la phase d’anticipation est corrélé positivement de façon significative à l’atrophie de la substance grise du PCC, SPL, PPN et le CN ; et la durée augmentée de la phase d’anticipation est corrélée négativement de façon significative à l’atrophie de la matière grise du AMS et du cervelet. Les réductions de la vitesse et de la longueur du premier pas sont liées de façon significative à l’atrophie de la matière grise dans le PMC, le PPN et le vermis cérébelleux, enfin, l’absence de freinage actif est corrélée à une diminution du volume de la matière grise du CUN. Ces résultats suggèrent que l'instabilité posturale des patients atteints de SLA est causée, au moins en partie, par le dysfonctionnement des régions et des réseaux connus pour être impliqués dans l'initiation de la marche et dans le contrôle de l’équilibrePostural instability is frequently reported in Amyotrophic Lateral Sclerosis (SLA) patients. However, the neural mechanisms that contribute to postural instability in SLA patients remain largely unknown. In comparison to both SLA patients without postural instability and controls, SLA patients with postural instability presented an altered anticipatory postural adjustment (APA) phase with a decreased posterior displacement of the center of foot pressure (CP) and a increased APA duration, decreased length and velocity of the first step and deficit of the dynamic postural control with a dramatic decreased braking index. Conversely, the gait initiation was not significantly modified in SLA patients without postural instability in comparison to controls. The reduced posterior CP displacement during the APA was significantly related to reduced grey matter volume of the left PCC, left SPL, right PPN and caudate nucleus, and the increased APA duration to the reduced grey matter volume of the left AMS and right cerebellum. The reduced velocity of the first step was significantly related to a decreased grey matter volume within the left PMC, right PPN and cerebellar vermis and the reduced braking index to decreased grey matter volume of the right CUN. These results suggest that postural instability of SLA patients result, at least partly, from dysfunction of brain regions and networks known to be involved in gait initiation and balance controls in human
3
Heide, Dr Bernd. "A Method For Modifying Segmented Human Voxel Models." Universitätsbibliothek Chemnitz, 2002. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200200823.
Анотація:
A method for modifying segmented human voxel models is depicted. The method is a practical approach to set up voxel models for dose calculations in medical physics. It could also be applied in other fields requiring human voxel models. The basic strategy of the method is: 1. Generate triangulated surfaces from voxel representations of the objects (organs, bones, or tissues) of a segmented human voxel model. 2. Perform surface deformations and/or rearrangements. 3. Reconstruct voxel representations from the triangulated surfaces and put them back into the segmented human voxel model. The voxel volume of the modified organs can be adjusted up to the volume of half a voxel. The practicability of the method is demonstrated by means of the spleen of a leukaemia patientEs wird eine praktische Methode zum Verändern von segmentierten menschlichen Voxel-Modellen dargelegt. Die Methode kann in der Medizinphysik im Zusammenhang mit Strahlendosisberechnungen angewendet werden. Sie kann jedoch auch in anderen Gebieten benutzt werden, bei denen menschliche Voxel-Modelle zur Anwendung kommen. Die grundlegende Strategie der Methode besteht aus den folgenden Schritten: 1. Erzeugung triangulierter Oberflächen aus Objekten (Organen, Knochen, Geweben) eines segmentierten menschlichen Voxel-Modells. 2. Durchführung interaktiver Oberflächendeformationen und/oder Verschiebungen. 3. Re-Überführung der triangulierten Oberflächen in Voxel-Darstellungen der Organe und Rückschreibung in das segmentierte menschliche Voxel-Modell. Das Voxel-Volumen der modifizierten Organe kann mindestens bis auf ein halbes Voxel genau eingestellt werden. Die Anwendbarkeit der Methode wird anhand der Milz einer Leukämie-Patientin demonstriert
4
Vogel, Helena [Verfasser]. "Modelle zur Leistungsverschlechterung von Turboluftstrahltriebwerken / Helena Vogel." München : Verlag Dr. Hut, 2019. http://d-nb.info/1178899020/34.
5
Mazzolini, Ryan. "Procedurally generating surface detail for 3D models using voxel-based cellular automata." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/20502.
Анотація:
Procedural generation is used extensively in the field of computer graphics to automate content generation and speed up development. One particular area often automated is the generation of additional colour and structural detail for existing 3D models. This empowers artists by providing a tool-set that enhances their existing work-ow and saves time. 3D surface structures are traditionally represented by polygon mesh-based models augmented by 2D mapping techniques. These methods can approximate features, such as caves and overhangs, however they are complex and difficult to modify. As an alternative, a grid of voxels can model 3D shapes and surfaces, similar to how 2D pixels form an image. The regular form of voxel-based models is easier to alter, at the cost of additional computational overhead. One technique for generating and altering voxel content is by using Cellular Automata (CA). CAs are able to produce complex structures from simple rules and also easily map to higher dimensions, such as voxel datasets. However, creating CA rule-sets can be difficult and tedious. This is especially true when creating multidimensional CA. In our work we use a grammar system to create surface detail CA. The grammar we develop is similar to formal grammars used in procedural generation, such as L-systems and shape grammars. Our system is composed of three main sections: a model converter, grammar and CA executor. The model converter changes polygon-mesh models to and from a voxel-based model. The grammar provides a simple language to create CA that can consider 3D neighbourhoods and query parameters, such as colour or structure. Finally, the CA executor interprets the produced grammars into surface-oriented CAs. The final output of this system is a polygon-mesh model, altered by the CA, which is usable for graphics applications. We test the system by replicating a number of CA use-cases with our grammar system. From the results, we conclude that our grammar system is capable of creating a wide range of 3D detail CA. However, the high resolution of resulting meshes and slow processing times make the process more suited to o_-line processing and pre-production.
6
Dawa, Hazem. "Modélisation surfacique par voxels d'une structure osseuse. Application à la simulation d'ostéotomies faciales." Toulouse 3, 1997. http://www.theses.fr/1997TOU30080.
Анотація:
Cette etude consiste tout d'abord, en la definition d'une structure de donnees permettant la representation (visage de patient), connue sous la forme des donnees volumiques issues de couches scanner. Sont ensuite definies et presentees les procedures a appliquer a cette structure de donnees, afin d'assurer les traitements classiques sur une structure osseuse : visualisation, transformations geometriques, operations booleennes. La premiere partie est consacree a l'aspect modelisation et visualisation de l'etude. Il s'agit d'un expose des principales techniques de representation utilisees dans ce domaines, et regroupees dans les deux methodes : volumique et surfacique. Nous justifions ensuite le choix d'une representation surfacique par voxels exterieurs, sur les criteres de capacite de memoire et de temps de traitement. En effet, les structures osseuses considerees sont definies par un tres grande quantite de donnees, et nous nous placons dans le cas (le plus courant) ou les ressources disponibles -capacite de memoire et puissance de calcul- sont moyennes voire faibles. Les manipulations de la structure osseuse sont presentees dans la deuxieme partie. Guides par l'application simulation d'osteotomies faciales, nous presentons les procedures a appliquer a la structure de donnees permettant de realiser les differentes transformations souhaitees par le chirurgien sur le massif osseux. La troisieme partie est orientee vers la simulation des osteotomies faciales. On y considere la representation de la partie cutanee du visage, ainsi que l'estimation des deformation entrainees par les deplacements osseux.
7
Falk, Thorsten [Verfasser], and Olaf [Akademischer Betreuer] Ronneberger. "From voxels to models : towards quantification in 3-D confocal microscopy." Freiburg : Universität, 2016. http://d-nb.info/1119898862/34.
8
Côté, Jean-Francois. "Un modèle d'architecture 3D par voxels pour simuler les paramètres structuraux des couverts forestiers de conifères." Mémoire, Université de Sherbrooke, 2006. http://savoirs.usherbrooke.ca/handle/11143/2443.
Анотація:
La qualité des mesures indirectes de la structure du couvert végétal repose principalement sur la connaissance de l'architecture des couverts végétaux. Nous avons développé des modèles d'architecture du couvert forestier selon plusieurs niveaux de détails afin d'aider l'interprétation des images de télédétection. C'est le cas pour le modèle VoxTreK (Voxel Tree with 3D-Kites) qui utilise les données géométriques recueillies sur le terrain pour reproduire l'architecture du couvert au niveau de détail des branches. Ce modèle est conçu pour son utilisation par les modèles de réflectance en télédétection. Toutefois, la photographie hémisphérique est utilisée dans cette étude comme complément aux approches de télédétection satellitaire ou aéroportée pour sa capacité à déceler un plus grand détail de la structure du couvert. L'objectif principal est de déterminer les apports du modèle d'architecture par voxels VoxTreK dans l'estimation des paramètres structuraux à l'aide de la photographie hémisphérique."--résumé abrégé par UMI.
9
LOPEZ, COELLO LIMBANO IVAN 784713, and COELLO LIMBANO IVAN LOPEZ. "Cálculo con GEANT4 de valores S en maniquí hembra/macho tipo voxel de modelo murino (MOBY) para el 67Ga." Tesis de maestría, Universidad Autónoma del Estado de México, 2018. http://hdl.handle.net/20.500.11799/98794.
Анотація:
La medicina nuclear y radioterapia, aunque ya están bien establecidas siguen evolucionando rápidamente gracias al uso de modelos animales que ayudan a de_nir una dosimetría más precisa en los procedimientos de imagen molecular y dosimetría interna. Modelos de animales pequeños como el ratón han sido ampliamente usados en protocolos experimentales que involucran el uso de radiaciones ionizantes. Los estudios de dosimetría en animales pequeños son usados principalmente en la terapia preclínica de radionúclidos para evaluar la toxicidad de los nuevos radiofármacos antes de comenzar a ser aplicados en humanos. Entendiendo la respuesta de dosis, los efectos de la radiación y la toxicidad del radiofármaco hacen que estos estudios sean muy importantes ya que pueden ser trasladados a estudios preclínicos en humanos. La evaluación de la e_cacia terapéutica es esencial y debe basarse en una dosimetría precisa la cual a su vez está basada en modelos geométricos realistas que describen adecuadamente el transporte de radiación. El propósito de este trabajo fue determinar el impacto que tienen las diferencias anatómicas de las hembras y machosde murinos de la cepa CD-1 en la dosimetría interna , esto se logró a través de la simulación Monte Carlo con el código de transporte Geant4, la plataforma de manejo de imágenes GATE y un maniquí especi_co por genero creado con el software MOBY. Dos modelos fueron creados con diferentes masas para calcular los valores S del radioisotopo 67Ga. La simulación fue validada calculando valores S para 18F y comparando estos valores con los reportados en otros trabajos.
10
Kenned, Florêncio da Costa Roberto. "Radiografias digitais sintéticas utilizando modelos computacionais de exposição do tipo Fantomas de Voxels EGS4." Universidade Federal de Pernambuco, 2008. https://repositorio.ufpe.br/handle/123456789/9725.
Анотація:
Made available in DSpace on 2014-06-12T23:15:51Z (GMT). No. of bitstreams: 2
arquivo8635_1.pdf: 1894928 bytes, checksum: 40ee3795d9c5ac34908d1e84d005d489 (MD5)
license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)
Previous issue date: 2008As imagens radiográficas quando digitalizadas podem ser agrupadas em arquivos para gerar um modelo antropomórfico de elementos de volume, chamados fantomas tal como o MAX (Male Adult voXel) e o FAX (Female Adult voXel). Estes fantomas acoplados a um código Monte Carlo, que simula o transporte de radiação na matéria como o EGS4 (Elétron Gama Shower-versão 4), e um algoritmo de uma fonte radioativa constituem um Modelo Computacional de Exposição (MCE). Este modelo além de possuir o código e a fonte radioativa, possui sub-pastas com os fantomas MAX/FAX e um código do usuário (USERCODE). Nas pastas dos fantomas MAX/FAX encontram-se arquivos importantes para execução do MCE, tais como: mspectra.dat, o pegs4.dat,o max/fax.data,o max/fax.bone.data e o expo.input que contém dados operacionais do usuário e construído com a utilização do software FANTOMAS. Na pasta USERCODE foi declarada no arquivo max/fax.code.mor uma matriz, específica para este trabalho, chamada de RADDIGITAL que é preenchida pela transferência, feita pelo software DIP (Digital Image Processing), de valores de energia (em keV) dos arquivos EnergiaPorVoxel.dat oriundos da execução do MCE. A compilação de toda massa de dados (código EGS4, fantomas MAX/FAX com seus arquivos e os arquivos da pasta USERCODE gerou os arquivos Max.for e Fax.for que recompilados e vinculados geraram os arquivos Max.exe e Fax.exe que executam os MCE. A execução dos MCE geraram arquivos externos com informações de energia depositada nos voxels. Com estes arquivos, com o fantoma segmentado e utilizando o software DIP pode-se construir fantomas de saída com base em energia depositada por voxel e com base em valores de dose efetiva. Para se obter nos fantomas baseados na dose efetiva foi criado internamente no software DIP um vetor contendo os fatores de ponderação tecidual à radiação, aqui chamados de wDIP, calculado neste trabalho com base nos dados de radiosenssibilidade da ICRP 60. Desta forma, foram obtidos os fantomas contendo informações das frações de dose efetiva dos órgãos e tecidos radiosenssíveis. Assim foi possível ajustar, por exemplo, a energia máxima para 255 no fantoma de saída, chamados de fantomas sintéticos, para se ter uma distribuição de energia resultando numa distribuição de tons de cinza similar à observada nas radiografias convencionais e nas imagens de 8 bits. Os fantomas sintéticos são uma pilha cujas vistas radiográficas sagitais, coronais e transversais, em qualquer profundidade, foram chamadas de radiografias digitais sintéticas, onde utilizou-se técnicas de realce de imagens digitais no domínio espacial com a utilização do software DIP. A utilidade clínica destes fantomas pode diminuir os erros relacionados com a excessiva repetição de exames radiográficos convencionais e reduzir assim a dose recebida pelos pacientes
11
Heckmann, Lotta Verfasser], Barbara [Akademischer Betreuer] Drossel, and Michael [Akademischer Betreuer] [Vogel. "Thermodynamik und Phasenverhalten einfacher Modelle für Wasser / Lotta Heckmann. Betreuer: Barbara Drossel ; Michael Vogel." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2013. http://d-nb.info/1108094864/34.
12
Heckmann, Lotta [Verfasser], Barbara Akademischer Betreuer] Drossel, and Michael [Akademischer Betreuer] [Vogel. "Thermodynamik und Phasenverhalten einfacher Modelle für Wasser / Lotta Heckmann. Betreuer: Barbara Drossel ; Michael Vogel." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2013. http://nbn-resolving.de/urn:nbn:de:tuda-tuprints-37923.
13
Van, Zyl Joe. "Objective determination of vowel intelligibility of a cochlear implant model." Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-03082009-174318/.
14
Gao, Jing [Verfasser], Thomas [Akademischer Betreuer] Weiland, Irina [Akademischer Betreuer] Munteanu, and Reiner [Akademischer Betreuer] Anderl. "Generation of Postured Voxel-based Human Models Used for Electromagnetic Applications / Jing Gao. Betreuer: Thomas Weiland ; Irina Munteanu ; Reiner Anderl." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2012. http://d-nb.info/1106113713/34.
15
Feldmann, Stefan [Verfasser], Birgit [Akademischer Betreuer] Vogel-Heuser, Helmut [Gutachter] Krcmar, Birgit [Gutachter] Vogel-Heuser, and Gertrude [Gutachter] Kappel. "Diagnosis and Handling of Inconsistencies in Heterogeneous Models of Automated Production Systems / Stefan Feldmann ; Gutachter: Helmut Krcmar, Birgit Vogel-Heuser, Gertrude Kappel ; Betreuer: Birgit Vogel-Heuser." München : Universitätsbibliothek der TU München, 2019. http://d-nb.info/119840244X/34.
16
Brída, Ján. "Voxelizace 3D modelů a jejich zpracování s využitím GPU." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2017. http://www.nusl.cz/ntk/nusl-363786.
Анотація:
This thesis focuses on the analysis of the latest techniques for surface and solid binary voxelization of 3D models. It briefly describes current trends in this problematics and identifies a suitable method with an aim to parallelize the given solution on GPUs. It concretely explains the implementation process of the selected algorithm described in the paper Fast Parallel Surface and Solid Voxelization on GPUs , which produces a sparse voxel octree. The results are very close to those of the original authors. A new solution for extracting a smooth isosurface from this structure based on Marching Cubes is presented as well, providing up to 98 % reduction of the traversed cubes in higher resolutions. The resulting implementation is a framework usable for further voxel scene processing.
17
SANTOS, Adriano Márcio dos. "Desenvolvimento de um modelo computacional para cálculos de dose absorvida em órgãos e tecidos do corpo humano nas situações de exposições acidentais." Universidade Federal de Pernambuco, 2006. https://repositorio.ufpe.br/handle/123456789/9664.
Анотація:
Made available in DSpace on 2014-06-12T23:15:41Z (GMT). No. of bitstreams: 2
arquivo9084_1.pdf: 2082722 bytes, checksum: 16498a33dff006a2b3ac65bb3600d937 (MD5)
license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)
Previous issue date: 2006A exposição a um campo de radiação pode ser de natureza medica, ambiental, ocupacional ou acidental, mas em todos os casos, o principal objetivo é a determinação da dose absorvida no corpo inteiro ou a distribuição da dose absorvida em órgãos e tecidos específicos. Nos anos recentes, as estimativas de dose absorvida no corpo humano se tornaram mais precisas devido aos avanços da tecnologia moderna nas áreas de instrumentação e desenvolvimento de computadores. Além dos dosímetros e métodos biodosimétricos, existem os modelos computacionais de exposição baseados nos métodos Monte Carlo (MC) para o cálculo da dose absorvida em órgãos e tecidos. Para simular corretamente os processos de transporte da radiação no corpo humano, o código computacional MC pode ser acoplado a um fantoma antropomórfico de voxels, que atualmente pode ser considerado como a melhor representação da natureza do corpo humano para o propósito de determinação da dose absorvida. Neste trabalho, um modelo computacional de exposição foi desenvolvido pelo acoplamento do código Monte Carlo EGS4 ao fantoma de voxels MAX, que foi adequadamente modificado para permitir especialmente a avaliação da dose absorvida em humanos expostos a fontes externas de radiação em situações acidentais. Para adaptar facilmente o modelo de exposição MAX/EGS4 as situações acidentais, uma fonte pontual generalizada foi desenvolvida para ser colocada em posições arbitrárias com respeito ao corpo humano. As propriedades funcionais desta fonte pontual generalizada foram verificadas com um fantoma Alderson-Rando (AR). O fantoma físico AR foi digitalizado por um tomógrafo computadorizado e as imagens segmentadas do fantoma AR virtual foram subseqüentemente conectadas ao código MC EGS4. Os dados das exposições experimentais do fantoma físico AR foram comparados aos resultados obtidos de correspondentes simulações de exposições do fantoma AR virtual com o código MC EGS4. Aplicações do modelo de exposição acidental MAX/EGS4 foram demonstradas neste estudo para dois acidentes radiológicos selecionados que aconteceram em Yanango (Peru) e Nesvizh (Belarus). De acordo com as informações relatadas nos correspondentes relatórios da IAEA (International Atomic Energy Agency), as condições de exposição dos dois acidentes foram simuladas com o modelo de exposição MAX/EGS4, e no caso do acidente em Nesvizh (Belarus) incluiu uma modificação na postura do fantoma MAX. Os resultados mostraram que o modelo de exposição MAX/EGS4 pode ser ajustado corretamente para condições de irradiações específicas, e doses absorvidas em tecidos e órgãos radiossensíveis resultantes de exposições acidentais podem ser determinadas com precisão suficiente, condição crucial para o tratamento médico de indivíduos expostos
18
Hypeš, Tomáš. "Procedurální generování voxelových modelů." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2019. http://www.nusl.cz/ntk/nusl-403194.
Анотація:
This thesis deals with procedural generation techniques and its use in the creation of voxel models. The techniques that have been used are Perlin Noise, Voronoi diagram, L-systems etc. This knowledge is then used to create a world generator for computer game with open world. This game provides players with the ability to modify this world and use its creativity, for example, in building construction. The game, however, will not give to the player all options for free, but for example for build, he or she will first have to find and mine the material. The game has been written in programming language C++ with the use of libraries Boost, SDL and OpenGL.
19
Côté, Jean-Francois. "Un modèle d'architecture 3D par voxels pour simuler les paramètres structuraux des couverts forestiers de conifères." [S.l. : s.n.], 2006.
20
WAGNER, GUSTAVO NUNES. "INTERACTIVE VISUALIZATION OF MASSIVE ENGINEERING MODELS IN THE OIL & GAS INDUSTRY USING THE FAR VOXELS ALGORITHM." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10718@1.
Анотація:
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORProjetos recentes de Estruturas Offshore criaram a necessidade de prototipação virtual de modelos de CAD massivos. Esses modelos tipicamente têm centenas de milhões de triângulos e, por essa razão, não podem ser enviados diretamente para as placas gráficas atuais que podem renderizar interativamente apenas alguns milhões de triângulos. Existem várias abordagens para lidar com esse problema incluindo uma nova estratégia de uso de impostores baseada na visualização de Voxels. Essa estratégia é promissora, já que lida bem com níveis de detalhe, oclusão e armazenamento em memória secundária. Esta dissertação apresenta uma variação do algoritmo de Voxels Distantes (Far Voxels), que é implementada e testada sobre modelos de CAD típicos. Finalmente, a partir desses testes, a dissertação apresenta algumas conclusões e sugestões para trabalhos futuros.
Current projects of Offshore Structures require virtual prototyping of huge CAD models. These models usually have hundreds of millions of triangles and for this reason they cannot be sent directly to current graphical boards that can render interactively only a few millions of triangles. There are many different approaches to deal with this problem including a new impostor strategy based on Voxel visualization. This strategy is promising because it deals well with level of detail, occlusion and out of core model storage. This dissertation presents a variant of the Far Voxels algorithm. This variant is implemented and tested against typical CAD models. Finally, from these tests, the dissertation presents some conclusions and suggestions for future work.
21
Birck, Alan Rodrigues. "Drivers de Customer Equity e vendas futuras : uma aplicação do modelo de Vogel, Evanschitzky, Ramasesham no B2B." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/101506.
Анотація:
Em um ambiente em que o marketing busca formas de avaliar os impactos de suas ações, Vogel, Evanschitzky e Ramaseshan (2008) sugerem que o uso do customer equity (CE), como uma medida do comportamento futuro de clientes de uma empresa, é um ativo estratégico que exige um gerenciamento efetivo com monitoramento tanto para detectar sinais de erosão neste valor, como para adequar programas para melhorá-lo. Vogel et al. (2008) associaram os condutores de CE, proposto por Rust, Zeithaml e Lemon (2000) e vendas futuras, contribuindo, em especial, com um modelo que inclui um construto de lealdade e foca na predição de vendas futuras, dado que valor de vida do cliente (CLV) é um difícil conceito para ser medido e está fora do alcance da maior parte das empresas. Diante da contribuição que essa técnica traz tanto para o avanço acadêmico da área de marketing metrics quanto para a prática empresarial, esta dissertação tem como enfoque a aplicação do modelo de Vogel et al. (2008), no B2B. Suas principais contribuições são: primeiro, adaptar e utilizar o modelo no contexto de serviços no B2B, estendendo a sua verificação a um universo mais amplo; segundo, testar se o modelo adaptado poderia produzir resultados tão consistentes quanto os encontrados pelos autores; terceiro, sugerir recomendações para a aplicação do modelo em outros segmentos. Para realização do estudo foram selecionadas duas empresas de segmentos diferentes que possuem outras companhias como clientes, uma delas do ramo de serviços ao varejo e outra uma distribuidora de medicamentos que permitiram acesso a um total de 253 de seus clientes. Para a empresa de serviços ao varejo identificou-se resultados em direção e magnitude semelhante ao estudo de Vogel et al. (2008), sugerindo que o modelo poderia ser aplicado no universo B2B; para a distribuidora, entretanto, os achados não demonstraram associação entre as variáveis, sinalizando uma fragilidade do modelo na predição de vendas futuras. Os resultados sugerem que o modelo adaptado poderia ser empregado no B2B, porém não é robusto. Desta forma apenas pode ser aplicado apenas sob condições específicas que precisam ser verificadas antes da aplicação.In an environment where marketing seeks ways to assess the impacts of their actions , Vogel , and Evanschitzky Ramaseshan (2008) suggest that the use of customer equity (CE), as a measure of future customer behavior of a company, is a strategic asset that requires effective management with both monitoring for signs of erosion in this figure , as to tailor programs to improve it . Vogel et al. (2008) associated drivers from EC , proposed by Rust , Zeithaml and Lemon (2000) and future sales, contributing in particular to a model that includes a construct of loyalty and focuses on the prediction of future sales, since customer lifetime value (CLV) is a difficult concept to be measured and is beyond the reach of most companies . Given the contribution that this technique brings both academic advancement in the area of marketing metrics and for business practice, this dissertation focus on the application of Vogel et al. (2008), in the B2B. His main contributions are: first , to adapt and use the model in the context of B2B services, extending the verification to a broader universe; Second, to test whether the adapted model could produce results as consistent as those found by the authors; thirdly, to suggest recommendations for the application of the model in other segments. To conduct the study, two companies from different segments that have other companies as clients were selected , one of them in the service industry to retail and a distributor for drugstores that allowed access to a total of 253 clients. For services company was identified similar results, in direction and magnitude, toward the study of Vogel et al. (2008) , suggesting that the model could be applied in the B2B universe; for the distributor , however, the findings did not show association between the variables, indicating a weakness of the model in predicting future sales. The results suggest that the adapted model could be employed in B2B, but it is not robust. Thus, it can be applied only under specific conditions that must be verified before application.
22
Vogel, Tobias [Verfasser]. "Wissensbasiertes und prozessorientiertes Innovationsmanagement WPIM : Innovationsszenarien, Anforderungen, Modell und Methode, Implementierung und Evaluierung anhand der Innovationsfähigkeit fertigender Unternehmen / Tobias Vogel." Hagen : Fernuniversität Hagen, 2012. http://d-nb.info/1026249368/34.
23
Vogel, Florian [Verfasser], Nelia [Akademischer Betreuer] Wanderka, John [Akademischer Betreuer] Banhart, and Uwe [Akademischer Betreuer] Glatzel. "Charakterisierung der hierarchischen Mikrostruktur einer Ni-Al-Ti Modell-Legierung / Florian Vogel. Gutachter: John Banhart ; Uwe Glatzel. Betreuer: Nelia Wanderka." Berlin : Technische Universität Berlin, 2014. http://d-nb.info/1066163456/34.
24
Vogel, Frank-Robert [Verfasser]. "Projektsteuerung öffentlicher Hochbauprojekte : parametergestütztes Modell der Projektsteuerung mit dem Ziel der Einhaltung des vorgegebenen Budgetrahmens abgeleitet von realisierten öffentlichen Hochbauprojekten / Frank-Robert Vogel." Kassel : Kassel University Press, 2009. http://d-nb.info/1007023007/34.
25
ALVES, Marcelo Severo. "Desenvolvimento de um sistema computacional para edição de objetos 3D e análise de resultados dosimétricos." reponame:Repositório Institucional da UFPE, 2013. https://repositorio.ufpe.br/handle/123456789/10140.
Анотація:
Submitted by Amanda Silva (amanda.osilva2@ufpe.br) on 2015-03-03T14:06:42Z
No. of bitstreams: 2
Dissertação Marcelo Severo Alves.pdf: 9562145 bytes, checksum: 1265a897d4ccbb05cc57588d6306c571 (MD5)
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)Made available in DSpace on 2015-03-03T14:06:42Z (GMT). No. of bitstreams: 2 Dissertação Marcelo Severo Alves.pdf: 9562145 bytes, checksum: 1265a897d4ccbb05cc57588d6306c571 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013
Neste trabalho é apresentado um sistema computacional para edição de objetos 3D usados para modelagem de fantomas de malhas poligonais a serem acoplados a um Modelo Computacional de Exposição (MCE). Um MCE é composto por um fantoma computacional antropomórfico, um código Monte Carlo (MC) e um algoritmo simulador de uma fonte radioativa. O sistema computacional é composto, fundamentalmente, por aplicativos de código livres para edição dos objetos 3D, execução do MCE do tipo fantoma de voxel/EGSnrc e conversão entre imagens baseadas em voxels para malhas, e vice-versa, além de análise gráfica. O fantoma de voxel base utilizado foi o MASH3, do Departamento de Energia Nuclear da Universidade Federal de Pernambuco (DEN-UFPE), e os objetos 3D são propriedades do Grupo de Pesquisa em Dosimetria Numérica do Recife/PE (GDN). Ao MCE MASH3/EGSnrc foi acoplado um algoritmo representativo de uma fonte de 192Ir para simular um tratamento de braquiterapia de um câncer na porção média do esôfago. Para visualizar os objetos 3D e analisar os dados simulados foi desenvolvido o M3dDose, um aplicativo escrito na linguagem C# utilizando-se da tecnologia Windows Presentation Foundation (WPF), por meio do ambiente de desenvolvimento integrado Microsoft Visual Studio 2010. Para ilustrar as habilidades implementadas no M3dDose, é exibido um tumor no fantoma de malhas vetoriais e o resultado obtido por meio das avaliações dosimétricas realizadas no fantoma de voxels, além do mapeamento da dose na região tumoral, aqui referenciado como Mapa de dose Digital (MdD). Desta forma, utilizando-se de um aplicativo próprio desenvolvido para esta finalidade, o M3dDose, associado a alguns softwares livres como o Binvox, Blender, Fiji, Viewvox, EGSnrc e o DIP, propriedade do GDN, compôs-se um sistema computacional para edição e análise de resultados dosimétricos, em computadores equipados com o sistema operacional Windows.
26
Cordier, Nicolas. "Approches multi-atlas fondées sur l'appariement de blocs de voxels pour la segmentation et la synthèse d'images par résonance magnétique de tumeurs cérébrales." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4111/document.
Анотація:
Cette thèse s'intéresse au développement de méthodes automatiques pour la segmentation et la synthèse d'images par résonance magnétique de tumeurs cérébrales. La principale perspective clinique de la segmentation des gliomes est le suivi de la vitesse d'expansion diamétrique dans le but d'adapter les solutions thérapeutiques. A cette fin, la thèse formalise au moyen de modèles graphiques probabilistes des approches de segmentation multi-atlas fondées sur l'appariement de blocs de voxels. Un premier modèle probabiliste prolonge à la segmentation automatique de régions cérébrales pathologiques les approches multi-atlas classiques de segmentation de structures anatomiques. Une approximation de l'étape de marginalisation remplace la notion de fenêtre de recherche locale par un tamisage par atlas et par étiquette. Un modèle de détection de gliomes fondé sur un a priori spatial et des critères de pré-sélection de blocs de voxels permettent d'obtenir des temps de calcul compétitifs malgré un appariement non local. Ce travail est validé et comparé à l'état de l'art sur des bases de données publiques. Un second modèle probabiliste, symétrique au modèle de segmentation, simule des images par résonance magnétique de cas pathologiques, à partir d'une unique segmentation. Une heuristique permet d'estimer le maximum a posteriori et l'incertitude du modèle de synthèse d'image. Un appariement itératif des blocs de voxels renforce la cohérence spatiale des images simulées. Le réalisme des images simulées est évalué avec de vraies IRM et des simulations de l'état de l'art. Le raccordement d'un modèle de croissance de tumeur permet de créer des bases d'images annotées synthétiquesThis thesis focuses on the development of automatic methods for the segmentation and synthesis of brain tumor Magnetic Resonance images. The main clinical perspective of glioma segmentation is growth velocity monitoring for patient therapy management. To this end, the thesis builds on the formalization of multi-atlas patch-based segmentation with probabilistic graphical models. A probabilistic model first extends classical multi-atlas approaches used for the segmentation of healthy brains structures to the automatic segmentation of pathological cerebral regions. An approximation of the marginalization step replaces the concept of local search windows with a stratification with respect to both atlases and labels. A glioma detection model based on a spatially-varying prior and patch pre-selection criteria are introduced to obtain competitive running times despite patch matching being non local. This work is validated and compared to state-of-the-art algorithms on publicly available datasets. A second probabilistic model mirrors the segmentation model in order to synthesize realistic MRI of pathological cases, based on a single label map. A heuristic method allows to solve for the maximum a posteriori and to estimate uncertainty of the image synthesis model. Iterating patch matching reinforces the spatial coherence of synthetic images. The realism of our synthetic images is assessed against real MRI, and against outputs of the state-of-the-art method. The junction of a tumor growth model to the proposed synthesis approach allows to generate databases of annotated synthetic cases
27
Robert-Ribes, Jordi. "Modèles d'intégration audiovisuelle de signaux linguistiques : de la perception humaine a la reconnaissance automatique des voyelles." Grenoble INPG, 1995. http://www.theses.fr/1995INPG0032.
Анотація:
Cette these concerne l'etude des modeles d'integration des informations auditives et visuelles en vue d'obtenir un modele plausible et fonctionnel pour la reconnaissance audiovisuelle des voyelles du francais. Nous passerons en revue les donnees de la litterature sur l'integration audiovisuelle en perception de parole. Nous presenterons ensuite quatre modeles et nous les classifierons selon des principes inspires a la fois de la psychologie experimentale et de la litterature sur la fusion de capteurs. Notre contrainte de plausibilite (conformite aux donnees experimentales) permettra d'eliminer deux modeles. Les deux modeles restants seront compares par rapport a nos propres resultats de perception audiovisuelle des voyelles ainsi que selon leurs performances fonctionnelles. Le resultat de cette comparaison nous montrera qu'un modele qui projette les deux entrees (auditive et visuelle) dans un espace intermediaire de nature motrice, est a la fois le plus conforme aux donnees experimentales et le plus performant pour la reconnaissance audiovisuelle des voyelles dans du bruit acoustique
28
Rinne, Vidar. "A Zoomable 3D User Interface using Uniform Grids and Scene Graphs." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-13360.
Анотація:
Zoomable user interfaces (ZUIs) have been studied for a long time and many applications are built upon them. Most applications, however, only use two dimensions to express the content. This report presents a solution using all three dimensions where the base features are built as a framework with uniform grids and scene graphs as primary data structures. The purpose of these data structures is to improve performance while maintaining flexibility when creating and handling three-dimensional objects. A 3D-ZUI is able to represent the view of the world and its objects in a more lifelike manner. It is possible to interact with the objects much in the same way as in real world. By developing a prototype framework as well as some example applications, the usefulness of 3D-ZUIs is illustrated. Since the framework relies on abstraction and object-oriented principles it is easy to maintain and extend it as needed. The currently implemented data structures are well motivated for a large scale 3D-ZUI in terms of accelerated collision detection and picking and they also provide a flexible base when developing applications. It is possible to further improve performance of the framework, for example by supporting different types of culling and levels of detail
29
Majid, Rajaa. "Modélisation articulatoire du conduit vocal : exploration et exploitation : fonctions de macro-sensibilité paramétriques et voyelles du français." Grenoble INPG, 1986. http://www.theses.fr/1986INPG0131.
30
Castelli, Eric. "Caractérisation acoustique des voyelles nasales du français : mesures, modélisation et simulation temporelle." Grenoble INPG, 1989. http://www.theses.fr/1989INPG0055.
31
Gavaldà, Ferré Núria. "Index of idiolectal similitude for the phonological module of English applied to forensic speech comparison." Doctoral thesis, Universitat Pompeu Fabra, 2013. http://hdl.handle.net/10803/123775.
Анотація:
The framework of the present PhD dissertation is the area that results from the overlap between the field of variationist sociolinguistics and forensic linguistics, which mainly concerns the study of variation between different individuals –inter-speaker variation– and variation within a single individual –intra-speaker variation– for forensic purposes. The primary objective of the present dissertation is twofold. On the one hand, it proposes a protocol for the creation of an Index of Idiolectal Similitude (IIS) for the phonological module of English that can effectively determine whether two oral samples show inter-speaker variation –which would indicate that the samples have been produced by two different individuals– or intra-speaker variation –which would allow to conclude that the samples have been produced by the same individual. On the other hand, the analysis of the fourteen variables proposed in a corpus that contains data on sixteen speakers and that is stratified according to measurement time –as a result of a real time study–, language contact and gender, provides an important contribution to the Base Rate knowledge, which constitutes one of the main challenges of current forensic linguistics.
Results show that inter-speaker variation is generally higher than intra-speaker variation, and that a speaker’s idiolectal style remains relatively stable over time. Therefore, the IIS is presented as an innovative quantitative tool which, together with other quantitative and qualitative techniques that the linguist acting as expert witness may have at their disposition, can help reach a conclusion regarding the probability of two samples having been produced or not by the same speaker.Aquesta tesi doctoral s’emmarca dins l’àrea comú on es troben els camps de la sociolingüística de la variació i la lingüística forense, en la qual es troba l’estudi de la variació entre diferents individus –variació inter-parlant– i la variació en del mateix individu –variació intra-parlant– amb finalitats forenses. La investigació té dos objectius principals. D’una banda, es proposa el protocol per a la creació d’un Índex de Similitud Idiolectal (ISI) per al mòdul fonològic de l’anglès que pot determinar de manera efectiva si dues mostres orals mostren variació inter-parlant –que indicaria que les mostres haurien estat produïdes per dos individus diferents– o variació intra-parlant –la qual cosa portaria a concloure que les mostres haurien estat produïdes pel mateix individu. D’altra banda, l’anàlisi de les catorze variables proposades en un corpus que conté setze parlants i que està estratificat per temps de mesura –com a resultat d’un estudi en temps real–, contacte de llengües i gènere biològic, comporta una contribució important a la referència de distribució poblacional (Base Rate Knowledge) que constitueix un dels grans reptes de la lingüística forense actual. Els resultats mostren que la variació inter-parlant és generalment més alta que la intra-parlant, i que l’estil idiolectal d’un individu es manté relativament estable malgrat el pas del temps. Per tant, l’ISI es presenta com una eina quantitativa innovadora que, juntament amb altres tècniques quantitatives i qualitatives que el lingüista forense pot tenir a la seva disposició, pot ajudar a prendre una decisió sobre la probabilitat que dues mostres hagin estat produïdes o no pel mateix parlant.
32
Staněk, Miroslav. "Určování stresu z řečového signálu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-255289.
Анотація:
Předložená disertační práce se zabývá vývojem algoritmů pro detekci stresu z řečového signálu. Inovativnost této práce se vyznačuje dvěma typy analýzy řečového signálu, a to za použití samohláskových polygonů a analýzy hlasivkových pulsů. Obě tyto základní analýzy mohou sloužit k detekci stresu v řečovém signálu, což bylo dokázáno sérií provedených experimentů. Nejlepších výsledků bylo dosaženo pomocí tzv. Closing-To-Opening phase ratio příznaku v Top-To-Bottom kritériu v kombinaci s vhodným klasifikátorem. Detekce stresu založená na této analýze může být definována jako jazykově i fonémově nezávislá, což bylo rovněž dokázáno získanými výsledky, které dosahují v některých případech až 95% úspěšnosti. Všechny experimenty byly provedeny na vytvořené české databázi obsahující reálný stres, a některé experimenty byly také provedeny pro anglickou stresovou databázi SUSAS.
33
Manivannan, M. "Resculpting In Voxel Modeling." Thesis, 1999. https://etd.iisc.ac.in/handle/2005/1522.
34
Manivannan, M. "Resculpting In Voxel Modeling." Thesis, 1999. http://etd.iisc.ernet.in/handle/2005/1522.
35
Chen, Lu-Kang, and 陳陸剛. "Layer Manufacturing Assistant Software for Voxel-based Models." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/8k387t.
Анотація:
碩士國立臺灣海洋大學
資訊工程學系
104
Along with the emerging of Industry 4.0, 3D printing is getting more attention in industries and academic society. Companies and laboratories use 3D printers to produce prototypes and products. Numerous research projects focus on the development of essential 3D printing technologies. Thus 3D printing plays an important role in modelling, prototyping, and manufacturing. The process of 3D printing starts at constructing a geometric model and exports the model to an STL file. Then, the model description is converted into machine codes. At the following stage, we send the machine codes to a 3D printer to manufacture the model. There are lots of software which can be used to construct geometric models, e.g. Blender, Tinkercad, and Sculptris. However, these tools are usually complicated and hard to learn for ordinary people with limited or no background knowledge. As a result, the complexity of geometric modelling tools becomes a hinder of 3D printing. In this thesis, we present a voxel-based 3D printing system to solve the problems. In terms of modeling, there are many ways to construct a geometric model. In surface modeling methods, a model is represented by vertices, edges, and faces. Constructive Solid Geometry (CSG) modelling utilizes basic components, logic expressions, and set operators to design a model. Freeform surface modeling employs parametric surface patches to form a model and manipulates the control points to modify the model’s shape. In a voxel-based modeling system, a model is constructed with voxels. Unlike the afore-mentioned geometric modelling strategies, voxel-based modelling fabricates a model by adding, deleting, and moving voxels directly. It can also use logic and morphological operations as well as geometric transformations to build a model or reshape an existing one. According to its regularity and discrete nature, voxel-based modelling is easier to learn and use. Besides, it enables us to define material for voxels and to compute the various geometric information, for examples the gravity center, the mass and volume of the model. Therefore, we dedicate our efforts on developing a 3D printing assistant program in this research. Our system consists of the following steps. At first, it fetches the target voxel-based model from a disk file. Then it divides the model into slices in the z-direction. The resultant slices resemble 2D images. At the following step, these images are processed to generate printing roads and filling patterns. Finally, the computed printing roads and filling patterns are converted into different G-codes and are kept in a disk file. In the proposed system, the target geometric model is composed of voxels. We can generate the model by using our voxel-based modelling system or import it and convert it into a voxel model. For example, a polygonal model can be transformed into a voxel model through voxelization, and a segmented volume data can be converted directly by binarization. In order to widen the applications of the proposed system, we incorporate the concept of distance field in our system. As a result, we are able to change the thickness of the model’s walls to produce a hollow model or a solid model. Furthermore, we combine projection mapping algorithms with distance field computation to achieve different carving effects. Therefore, troughs and crests can be created on the model’s surface. In this research, an innovative modelling method is developed to produce water-marking in the target model. To preview 3D printing processes and to prevent printing errors, we also develop a 3D printing simulator to perform 3D printing result in a virtual volume space.
36
Gao, Jing. "Generation of Postured Voxel-based Human Models Used for Electromagnetic Applications." Phd thesis, 2012. http://tuprints.ulb.tu-darmstadt.de/2866/1/PhD_Dissertation_Jing_Gao.pdf.
Анотація:
The main contribution of this dissertation is the development of a poser program package, which can deform a voxel-based human body model named HUGO to allow the genera-tion of common postures that people often use in normal life. To illustrate the usefulness of this poser program, two electromagnetic applications are presented. As a low frequency application example in electrical engineering, the first one simulates and analyzes the step voltage due to a lightning strike in detail with the help of two postured human body models. The second one studies the influence of human’s posture on specific absorption rate (SAR) calculation as a high frequency electromagnetic application example.
With the development of medical technique, computer graphics and computational elec-tromagnetics, high resolution and anatomically realistic whole-body voxel-based human models have been recently developed and widely used in computation of induced elec-tromagnetic fields and SAR in the human body. However, voxel models’ unchangeable posture strongly limits related researches when simulating a realistic scenario in which people have a lot of different postures. In this dissertation, a poser program package, which is an improved version of the well known free form deformation (FFD) technique in computer graphics, was developed to overcome this problem. The poser program can import and render the original voxel dataset, set rotation angles of different joints with a simplified human model, generate postured human models, and export the postured hu-man models as new voxel dataset files. With its help, the original voxel-based human model can be deformed smoothly, continuity of internal tissues and organs can be main-tained, and masses of different tissues and organs can be conserved at a reasonable level. In order to generate a postured human model with correctly anatomic structure, a segmen-tation approach was developed to separate arms away from the trunk. Deformation of the knee joint was dealt with separately to avoid unreasonable deformation of the femur and tibia, and to realize movement and rotation of the patella when the knee joint is bent.
As a typical application of the postured human models, internal electromagnetic fields in the walking and standing human body shocked by the step voltage caused by broken power line or lightning strike were simulated. In order to get a much longer stable time step than the value specified by the Courant limit for stability, the reduced c technique was applied for the first time to these electro-quasistatic simulations, after a thorough study. At last, because human’s posture can significantly affect the way in which the hu-man body absorbs electromagnetic radiation, whole body averaged SAR and localized SAR distribution of a sitting human model were calculated and compared to that of the standing human model for various incidence angles of the electromagnetic wave and for different environmental conditions.
37
Tseng, Hong-Hsi, and 曾泓熹. "Improving Japanese Acoustic Models by Sentence-end Vowel Models and Bidakuon Allophones." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/39620393105515921213.
Анотація:
碩士國立清華大學
資訊系統與應用研究所
99
Sentence-end vowel devoicing and bidakuon allophones are common problems in Japanese speech recognition. This thesis proposes the use of specialized models for sentence-end vowel phones to overcome the devoicing problem and an automatic transcription correction framework for bidakuon allophones. In this study, Mel-frequency cepstral coefficients (MFCC) and log energy are used as features for training speech recognition models. Sentence-end vowel models are adopted for each sentence during the training phase in order to improve the recognition performance at the end of the sentence. On the other hand, we use an automatic transcription correction framework to resolve the bidakuon allophone problem by an iterative correction method. The iterative correction method is based on thresholds trained from the ranking scores. The transcription is corrected gradually towards the actual pronunciation recorded in the training data. We use three types of performance measure to evaluate the effectiveness of the proposed methods. They are confidence measure based on phone model ranking, free-mola decoding, and sentence recognition. The experimental results show that using both of the proposed methods can effectively enhance the recognition performance of the baseline system.
38
Vogel, Eberhard [Verfasser]. "Flußgleichungen für das Kondo-Modell / vorgelegt von Eberhard Vogel." 2005. http://d-nb.info/977222446/34.
39
Hsu, Shih-Jung, and 許時榮. "In Vivo Measurement of 3-D Kinematics of the Cervical Spine Using Fluoroscopy with Voxel-Based Bone Models." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/33355355365500684200.
Анотація:
碩士臺灣大學
醫學工程學研究所
95
The human spine is a complex structure. It protects spinal cord and transfer weight of head and trunk to pelvis. The spinal injury could affect nerve system, even cause paraplegia. Therefore, accurate 3-dimensional dynamic measurement of human spine kinematics could be helpful for spinal research, operation, and clinical management. However, present measurement techniques such as skin marker, medical imaging or in vitro studies have different kind of limitation. Therefore, the goal of this study is to combine 3-dimensional computer bone model and 2-dimensional fluoroscopic image to reconstruct the vertebra position, In order to provide an accurate, in vivo, non-invasive, 3-dimensional, dynamic measurement technique for human cervical spine. A fluoroscopy system was used to capture the cervical spine movement. Computed tomography was also used to reconstruct the bone model and digitally reconstructed radiography (DRR). Similarity measurement was used to compare the DRR and fluoroscopic image to find the model position and orientation using optimization. The validation experiment used 4 fresh connected porcine cervical spine cadavers (C1-7), bent into 4 different statuses, and fixed them with crystal balls using paraffin. The relation between crystal balls and vertebrae were defined by the computed tomography. Direct linear transformation and bi-plane fluoroscopy was used to locate the position of crystal balls and vertebrae. Static and dynamic images were captured by the bi-plane fluoroscopy. And the gold standard was provided by computed tomography. The registration accuracy of single plane and bi-plane fluoroscopy were determined. 2 optimization technique was compared and provide an solution for overlapping image. 4 normal subjects were participated in our study. The dynamic motion of flexion/extension, rotation, side bending were measured. 2 digitally cameras was also used for the movement of head. The contribution of each vertebra, coupled motion, and the finite helical axis were plotted. In the future, the method we develop will be adopted in other joint components and be extended in studying various kinds of diseases. Thus, the application of our method is helpful for the progress in the fields of orthopedic, rehabilitation, physical therapy, occupational therapy, sports medicine, computer-aid surgery, and implements designs, etc…