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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.
31

Uso de Refinamento Adaptativo em Escultura Virtual para CriaÃÃo Livre de Detalhes em Malhas Triangulares / Use of Adaptive Refinement in Virtual Sculpting for Free Insertion of Details in Triangular Meshes

Artur Pereira Sampaio 26 March 2012 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / Modelar objetos e personagens virtuais pode ser uma tarefa tediosa e difÃcil em vÃrias situaÃÃes. Um sistema de modelagem ideal deve ser capaz de representar qualquer mudanÃa ou caracterÃstica desejada pelo usuÃrio da forma mais rÃpida e transparente possÃvel, abstraindo toda a complexidade topolÃgica e matemÃtica, permitindo ao modelador concentrar-se exclusivamente no ato de criar, em oposiÃÃo a ter de especificar a posiÃÃo de cada elemento de forma manual. Tal sistema, se por um lado pode oferecer menor controle na determinaÃÃo da posiÃÃo de cada vÃrtice, alÃm de poder ser mais caro computacionalmente em algumas situaÃÃes, por outro simplifica enormemente o trabalho do artista, tornando a modelagem acessÃvel a qualquer usuÃrio. O presente trabalho abordou o problema das tÃcnicas de sculpting tradicionais de adicionar detalhes em malhas triangulares, com resoluÃÃo adaptativa e de forma interativa, em regiÃes com baixa densidade de vÃrtices. O algoritmo proposto busca subdividir faces e arestas na regiÃo de interesse do artista de modo a garantir uma quantidade de vÃrtices suficiente para representar o detalhe pretendido, sem necessidade de qualquer informaÃÃo adicional por parte do usuÃrio. O sistema resultante à capaz de encurtar a distÃncia entre a modelagem tradicional e a virtual, superando alguns dos principais mÃtodos propostos no meio acadÃmico no que tange à localidade das subdivisÃes e a manutenÃÃo de uma malha de boa topologia e de boa qualidade geomÃtrica, com poucos vÃrtices de alta valÃncia, ainda que o modelo original seja fracamente refinado, tornando possÃvel a incorporaÃÃo de novos detalhes. / Modeling of virtual objects and characters can be tedious and difficult in many situations. A modeling system should be capable of representing any change or feature desired by the user as quickly and transparently as possible, allowing the modeler to focus on the act of creating, as opposed to having to specify the position of each vertex manually. Such a system, if on the one hand offers less control in determining the position of each vertex, being computationally more expensive in some situations, on the other hand greatly simplifies the work of the artist, allowing character modeling to be accessible to any user. This work addressed the problem of traditional sculpting techniques to add details on triangular meshes with adaptive resolution, in regions with low vertex density. The proposed algorithm splits faces and edges in the region of interest of the artist to ensure the existence of a sufficient number of vertices to represent the desired detail, without any additional input requested. The resulting system is capable of bridging the gap between traditional and virtual modeling, improving some of the main methods proposed in the literature regarding the location of the subdivisions. Moreover, it also helps to maintain a good mesh topology and geometric quality, with few vertices of high valence, even if the original mesh is poorly refined, allowing the incorporation of new details.
32

What technique is most appropriate for 3D modeling a chair for a movie production?

Axelsson, Veronica January 2013 (has links)
Making 3D models with polygon modeling is the most common technique used for a 3D animated movie production, but there are also other good modeling techniques to work with. The aim of this thesis is to examine which of three chosen modeling technique is most appropriate to use for modeling a chair for a 3D animated movie production. I made three models of the same chair design and compared the results. The modeling technique used is polygon modeling, NURBS modeling and digital sculpting. A few factors were considered when I judged which one of the three techniques that was most suitable: The model's geometry, the workflow and the rendering (material and lightning). The three chairs were rendered in the same scene with the same lightning and settings. The results showed that the model's geometry and how smooth it is to work with the modeling technique matter most for judging which technique is the most appropriate. In addition, the results show that how the light falls and reflects the surface depends on how the geometry was placed on the model rather than which of the other modeling techniques that was used.
33

Thermomechanical Hot Tool Cutting and Surface Quality in Robotic Foam Sculpting

Bain, Joseph David January 2011 (has links)
For several years, research work has been carried out at the University of Canterbury aimed at the development of a rapid prototyping and manufacturing process referred to as Robotic Foam Sculpting (RFS). This system uses a six-axis industrial robot and electrically-heated hot-wire and hot-blade tools to sculpt desired parts from blocks of polystyrene foam. The vision for this system is that it will be able to rapidly create large volume foam models at low cost, for a range of potential applications. Parts produced by the RFS system can potentially be used as investment casting patterns, cores for sculptures and architectural details, demonstration and testing models, wind tunnel test models, and many other potential applications. At the beginning of the work reported in this thesis, there was very little understanding of the nature of the surfaces produced by hot-tool cutting of foam, very little knowledge of the range of input cutting conditions that affected the surface quality, and almost no understanding of the relationships between the cutting strategy and the nature of the surfaces being produced. In addition, there was little evidence of published work on these subjects that was sufficiently robust to be applicable to the RFS system. This research was concerned with rectifying this gap in the existing knowledge. There were a number of different focal areas for this research. These included the surface texture of surfaces cut with hot tools, the effects of cutting strategy on the surface quality in single-pass cutting of foam, the effects of cutting strategy on the surface quality in multi-pass cutting, and the application of a current-control system to control the surface quality in real time during a cut. In each of the focal areas the goal was to develop a detailed understanding of the nature of the different aspects of surface quality, to map the factor interactions and dependencies that controlled these aspects of surface quality, to develop methods for predicting the expected surface quality based on cutting strategy (and vice versa) and to develop techniques for minimising the surface errors. The detailed investigation of the surface texture of surfaces produced with hot-tool cutting is presented in Chapter 4. This chapter explores the characteristic nature of foam surfaces, presents the development of a method of measuring the surface texture of foam, and investigates the usefulness of a range of standard texture parameters for assessing foam surface quality. It is concluded in this chapter that common texture parameters based on the relative heights of surface features are not capable of reliably discriminating between different foam surfaces, so a new texture parameter (the 10%-Height Contiguous Diameter) is developed and implemented. Using this parameter, it is possible to reliably predict the surface texture to be expected for a given set of cutting conditions. Investigations of the cutting strategy in single-pass cutting are presented in Chapter 5. This chapter identifies the two key aspects of surface quality in single-pass cutting, the kerfwidth and the surface barrelling. Experimental work is carried out to investigate the relationships between these errors and the cutting strategy, and the factors that influence each of them are identified. In addition, statistical models are developed for the kerf along the length of a cut so that the kerf can be predicted based on cutting conditions. This chapter also includes a study of the cutting force in single-pass cutting, and develops models that allow the prediction of the expected cutting force for a given cutting strategy. A detailed study of the cutting strategy for multi-pass cutting is presented in Chapter 6. This study identifies the most significant surface errors in multi-pass cutting and determines the causes of each of these errors and the factor interactions and dependencies that have to be considered when developing a multi-pass cutting strategy. Once again, statistical models that allow the prediction of these surface errors based on cutting strategy, or the evaluation of cutting strategy parameters to achieve a desired surface quality, are developed. The models for cutting force in single-pass cutting are applied to multi-pass cutting, and it is found that these models can accurately predict the force in multi-pass cutting as well. The characterisation of the acoustic output in hot-tool cutting forms the subject matter of Chapter 7. This study establishes that the magnitude of the acoustic output is proportional to the cutting force experienced during the cut, and is therefore potentially suitable for use as a trigger signal for feedback current control. This would allow an acoustic signal to be used instead of the current force signal, which has a number of drawbacks that will be discussed in Chapter 2, the Background Material chapter. The specific trigger signal identified as being of most use is the acoustic output in the 4 – 12 kHz band, where the presence of any non-zero acoustic output above background noise is a reliable and repeatable indicator of the presence of thermomechanical cutting. The work presented in this thesis provides a detailed, quantitative, evidence-based and reliable understanding of the nature of the cutting strategy in hot-tool cutting of foam. The key cutting strategy parameters and the important aspects of surface quality for different cutting types are identified, the relationships between all these parameters are mapped, and quantitative models are developed that allow the output metrics like the surface quality or the cutting force to be predicted with a high degree of accuracy based on the input cutting strategy conditions. Armed with this understanding, it is possible to determine the most suitable cutting strategy for sculpting a given part, and to assess whether a given part can be sculpted with the RFS system. As such, the research problem posed at the start of this thesis has been largely solved, and the stage is set for further research to optimise the cutting strategy for sculpting different parts and to correct the remaining drawbacks of the RFS system to complete the development of a commercially-useful manufacturing system.
34

Segmentação dos nódulos pulmonares através de interações baseadas em gestos / Segmentation of pulmonary nodules through interactions based on in gestures

SOUSA, Héber de Padua 29 January 2013 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-08-16T21:13:39Z No. of bitstreams: 1 HeberSousa.pdf: 2248069 bytes, checksum: e89eac1d4562ac1f2f53007d699f9c71 (MD5) / Made available in DSpace on 2017-08-16T21:13:39Z (GMT). No. of bitstreams: 1 HeberSousa.pdf: 2248069 bytes, checksum: e89eac1d4562ac1f2f53007d699f9c71 (MD5) Previous issue date: 2013-01-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Lung cancer is one of the most common of malignant tumors. It also has one of the highest rates of mortality among cancers. The reason for this is mainly linked to late diagnosis of the disease. For early detection of disease is very helpful to use medical images as support, the most important being, CT. With the acquisition of digital images is becoming more common to use computer systems for medical imaging. These systems assist in the clinical diagnosis, disease monitoring, and in some cases is used as a support for surgery. Because the search for new ways of human-computer interaction, natural interaction arises, which aims to provide a form of control with higher cognition. This control is usually performed using gestures. Interactions of gestures can be useful in controlling medical imaging systems and can ensure necessary sterility in operating rooms, because they are not required contacts manuals. Among the activities computer assisted important for the treatment of lung cancer, we have the segmentation of nodules. The segmentation of nodules can be performed automatically, semiautomatically or interactively. It is useful to speed up the diagnostic process, taking measurements, or observe the morphological appearance of the nodule. The objective of this study is to investigate the use of natural interaction interface for activities such as medical image visualization and segmentation of pulmonary nodules. The paper proposes the study of interaction techniques based on gestures to segment nodules in an interactive and semiautomatic. Finally, conducting experiments to evaluate the techniques proposed in the items ease of use, intuitiveness, accuracy and comfortability / O câncer de pulmão é um dos mais comuns dentre os tumores malignos. Ele também possui uma das taxas mais altas de mortalidade dentre os tipos de câncer. O motivo disso está ligado principalmente ao diagnóstico tardio da doença. Para a sua detecção precoce é muito útil a utilização de imagens médicas como apoio, sendo a mais importante, a tomografia computadorizada. Com a aquisição digital das imagens está cada vez mais comum a utilização de sistemas computacionais de visualização médica. Estes sistemas auxiliam no diagnóstico clínico, no acompanhamento de doenças, e em alguns casos é utilizado como apoio a cirurgias. Em virtude da busca por novos meios de interação humano-computador, surge a interação natural, que objetiva uma forma de controle mais próximo cognitivamente das ações realizadas, e geralmente é realizada através de gestos. Interações por gestos podem ser úteis no controle de sistemas de visualização médica e podem garantir a esterilização necessária em salas cirúrgicas, pois não são necessários contatos manuais. Dentre as atividades assistidas por computador importantes para o tratamento do câncer pulmonar, temos a segmentação de nódulos. A segmentação de nódulos pode ser realizada de forma automática, semiautomática ou interativamente. Elas são úteis para agilizar o processo de diagnóstico, realizar medições, ou observar o aspecto morfológico do nódulo. O objetivo do presente trabalho é investigar a utilização da interação natural como interface para atividades de visualização de imagens médicas e segmentação de nódulos pulmonares. Foi implementada uma série de ferramentas de segmentação, interativas e semiautomáticas, controladas a partir de gestos. Estes gestos foram desenvolvidos a partir de imagens capturadas por uma câmera especial chamada Kinect, que traduz a imagem em mapas de profundidade, podendo medir com precisão a distância de objetos na cena. Ao final do estudo, foi realizado experimentos para avaliar as técnicas propostas nos quesitos facilidade de uso, intuitividade, conforto e precisão.
35

Uso de Refinamento Adaptativo em Escultura Virtual para Criação Livre de Detalhes em Malhas Triangulares / Use of Adaptive Refinement in Virtual Sculpting for Free Insertion of Details in Triangular Meshes

Sampaio, Artur Pereira January 2011 (has links)
SAMPAIO, Artur Pereira. Uso de Refinamento Adaptativo em Escultura Virtual para Criação Livre de Detalhes em Malhas Triangulares. 2011. 58 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências, Departamento de Computação, Fortaleza-CE, 2012. / Submitted by guaracy araujo (guaraa3355@gmail.com) on 2016-06-02T19:35:28Z No. of bitstreams: 1 2011_dis_apsampaio.txt: 25433 bytes, checksum: 9015898966f69dfce3b6faa62e988c32 (MD5) / Approved for entry into archive by guaracy araujo (guaraa3355@gmail.com) on 2016-06-02T19:42:44Z (GMT) No. of bitstreams: 1 2011_dis_apsampaio.txt: 25433 bytes, checksum: 9015898966f69dfce3b6faa62e988c32 (MD5) / Made available in DSpace on 2016-06-02T19:42:44Z (GMT). No. of bitstreams: 1 2011_dis_apsampaio.txt: 25433 bytes, checksum: 9015898966f69dfce3b6faa62e988c32 (MD5) Previous issue date: 2011 / Modeling of virtual objects and characters can be tedious and difficult in many situations. A modeling system should be capable of representing any change or feature desired by the user as quickly and transparently as possible, allowing the modeler to focus on the act of creating, as opposed to having to specify the position of each vertex manually. Such a system, if on the one hand offers less control in determining the position of each vertex, being computationally more expensive in some situations, on the other hand greatly simplifies the work of the artist, allowing character modeling to be accessible to any user. This work addressed the problem of traditional sculpting techniques to add details on triangular meshes with adaptive resolution, in regions with low vertex density. The proposed algorithm splits faces and edges in the region of interest of the artist to ensure the existence of a sufficient number of vertices to represent the desired detail, without any additional input requested. The resulting system is capable of bridging the gap between traditional and virtual modeling, improving some of the main methods proposed in the literature regarding the location of the subdivisions. Moreover, it also helps to maintain a good mesh topology and geometric quality, with few vertices of high valence, even if the original mesh is poorly refined, allowing the incorporation of new details. / Modelar objetos e personagens virtuais pode ser uma tarefa tediosa e difícil em várias situações. Um sistema de modelagem ideal deve ser capaz de representar qualquer mudança ou característica desejada pelo usuário da forma mais rápida e transparente possível, abstraindo toda a complexidade topológica e matemática, permitindo ao modelador concentrar-se exclusivamente no ato de criar, em oposição a ter de especificar a posição de cada elemento de forma manual. Tal sistema, se por um lado pode oferecer menor controle na determinação da posição de cada vértice, além de poder ser mais caro computacionalmente em algumas situações, por outro simplifica enormemente o trabalho do artista, tornando a modelagem acessível a qualquer usuário. O presente trabalho abordou o problema das técnicas de sculpting tradicionais de adicionar detalhes em malhas triangulares, com resolução adaptativa e de forma interativa, em regiões com baixa densidade de vértices. O algoritmo proposto busca subdividir faces e arestas na região de interesse do artista de modo a garantir uma quantidade de vértices suficiente para representar o detalhe pretendido, sem necessidade de qualquer informação adicional por parte do usuário. O sistema resultante é capaz de encurtar a distância entre a modelagem tradicional e a virtual, superando alguns dos principais métodos propostos no meio acadêmico no que tange à localidade das subdivisões e a manutenção de uma malha de boa topologia e de boa qualidade geométrica, com poucos vértices de alta valência, ainda que o modelo original seja fracamente refinado, tornando possível a incorporação de novos detalhes.
36

Seeing the wood for the trees : the experience of genograms and family sculpting during clinical psychology masters training

Meese, Debra Gail 04 October 2006 (has links)
This study seeks to explore students’ subjective and collective experience of an experiential family therapy module within the Clinical Psychology Masters training programme. It looks at the perceptions of nine trainee therapists who used genograms and family sculpting to present their family of origin. The study takes place after the completion of the practical internship year with the purpose of exploring relevant emotional, cognitive, social and therapeutic effects of this module. A literature survey reveals that the use of genograms and family sculpting during training has received little research interest as most studies have primarily focused on their use during therapy with clients and in supervision. There is a scarcity of literature available that pertains directly to psychologists themselves and their wider social context. An exploratory review has been made to supplement the literature and pertains to experiential programmes in training in general and the psychologist’s self in training. The epistemology that directs this research falls within a postmodern frame. The experience is viewed from within the broad systems perspective. This approach acknowledges the dynamic and recursive interactions which occur between and within systems, and permits a broad perspective to be taken that is inclusive rather than exclusive. A qualitative research design was selected as it lends itself particularly well to the study of the ‘lived realities’ of people within their context and allows the information gained from the study to guide the research process. Semi-structured open-ended in-depth interviews were used as they allow for greater freedom and fewer restrictions regarding direction for the participant. A thematic analysis was carried out in order for the central themes of the experience to emerge. These themes were discussed extensively and integrated with the literature available. The multigenerational family presentation seems to create greater awareness of patterns and roles and these insights have a pervasive impact in many contexts. Understandably, the trainees feel emotionally overwhelmed as they become both observer and observed, viewing their interaction from a third-person perspective. This awareness of process results in a loss of spontaneous response and initial debilitation which is associated with feelings of loss and isolation. The self-exploratory behaviour gives rise to a reflexive reconstruction of self as a result of the access to new meanings regarding the dynamics and relationships within the family system, which enhances understanding of the complex interplay of systems, and ultimately facilitates the processes of integration, repair and resolution. / Dissertation (MA (Clinical Psychology))--University of Pretoria, 2007. / Psychology / unrestricted
37

BUNKERKUNST / BUNKER KUNST

Bělica, Ondřej January 2017 (has links)
Bunker Kunst is an experimental and co-working platform, exploring potential and contemporary role of formal borders, post-military landscape and Czechoslovakian fotress built before 2WW. The point is a resuscitation of post-war space, where tens thousand of concrete mementos are still present. Deadly border line is becoming an environment of freedom. The project consist of theoretical, studio and site-specific works and happenings. More than 40 volunteers, students and specialists have been participating. Live long freedom!
38

Sculpting: An Improved Inside-out Scheme for All Hexahedral Meshing

Walton, Kirk S. 01 April 2003 (has links) (PDF)
Generating all hexahedral meshes on arbitrary geometries has been an area of important research in recent history. Hexahedral meshes have advantages over tetrahedral meshes in structural mechanics because they provide more accurate results with fewer degrees of freedom. Many different approaches have been used to create all-hexahedral meshes. Grid-based, inside-out, or superposition meshing all refer to a similar meshing approach that is a very common mesh generation technique. Grid-based algorithms provide the ability to generate all hexahedral meshes by introducing a structured mesh that bounds the complete body modeled, marking hexahedra to define an interior and exterior mesh, manipulating the boundary region between interior and exterior regions of the structured mesh to fit the specific boundary of the body, and finally, discarding the exterior hexahedra from the given body. Such algorithms generally provide high quality meshes on the interior of the body yet distort element at the boundary in order to fill voids and match surfaces along these regions. The sculpting algorithm as presented here, addresses the difficulty in forming quality elements near boundary regions in two ways. The algorithm first finds more intelligent methods to define a structured mesh that conforms to the body to lessen large distortions to the boundary elements. Second, the algorithm uses collapsing templates to adjust the position of boundary elements to mimic the topology of the body prior to capturing the geometric boundary.
39

Grafisk stil i Battle Royale-spel: Realistisk och stiliserad stil / Graphic style in Battle Royale games: Realistic and stylized style

Stamenkovic, Andrija January 2021 (has links)
Denna undersökning utfördes för att ta reda på hur spelare upplever de grafiska stilarna i relation till Battle Royale-genren inom spel. De grafiska stilarna ifråga är realistisk och stiliserad stil. Två likadana 3D-modeller skapades med skillnaden att ena är realistisk medan den andra är stiliserad. Dessa användes i en intervju-undersökning 3D-modeller för att besvara frågan. Undersökningen visar att respondenterna upplever de grafiska stilarna annorlunda från varandra men att de ser på stiliserad stil som den mest genreanpassade stilen för Battle Royale-genren. Undersökningen visar även på en svag tendens bland yngre deltagare att se stiliserad stil som genreanpassad samt att manliga deltagare prioriterade att den grafiska stil ska hjälpa dem prestera bättre i spelet. Denna undersökning utfördes på en liten testgrupp och den kvalitativa metoden kan ses som subjektiv. Vidare forskning kan generalisera området med en kvantitativ undersökning.

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