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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.
1

System Design and Analysis for Creating a 3D Virtual Street Scene for Autonomous Vehicles Using Geometric Proxies from a Single Video Camera

Wong, Timothy 01 June 2019 (has links) (PDF)
Self-driving vehicles use a variety of sensors to understand the environment they are in. In order to do so, they must accurately measure the distances and positions of the objects around them. A common representation of the environment around the vehicle is a 3D point cloud, or a set of 3D data points which represent the positions of objects in the real world relative to the car. However, while accurate and useful, these point clouds require large amounts of memory compared to other representations such as lightweight polygonal meshes. In addition, 3D point clouds can be difficult for a human to visually understand as the data points do not always form a naturally coherent object. This paper introduces a system to lower the memory consumption needed for the graphical representation of a virtual street environment. At this time, the proposed system takes in as input a single front-facing video. The system uses the video to retrieve still images of a scene which are then segmented to distinguish the different relevant objects, such as cars and stop signs. The system generates a corresponding virtual street scene and these key objects are visualized in the virtual world as low poly, or low resolution, models of the respective objects. This virtual 3D street environment is created to allow a remote operator to visualize the world that the car is traveling through. At this time, the virtual street includes geometric proxies for parallel parked cars in the form of lightweight polygonal meshes. These meshes are predefined, taking up less memory than a point cloud, which can be costly to transmit from the remote vehicle and potentially difficult for a remote human operator to understand. This paper contributes a design and analysis of an initial system for generating and placing these geometric proxies of parked cars in a virtual street environment from one input video. We discuss the limitations and measure the error for this system as well as reflect on future improvements.
2

Formulação do método dos elementos de contorno para análise de chapas com enrijecedores / Formulation of the boundary elements method for analysis of stiffned plates

Wutzow, Wilson Wesley 23 May 2003 (has links)
Neste trabalho, a formulação linear do método dos elementos de contorno - MEC, para elasticidade bidimensional, é empregada para estudo de domínios enrijecidos sendo os enrijecedores abordados de duas formas, a primeira muito conhecida trata-se da técnica de sub-região ou acoplamento MEC/MEC e a segunda também pelo mesmo tipo de acoplamento, mas agora condensando-se as variáveis do contorno para a linha central do enrijecedor. Esta técnica juntamente com a integração completamente analítica dos termos da equação Somigliana proporcionam bons resultados eliminando perturbações em enrijecedores finos. Com o intuito de obter melhores resultados aplica-se ainda a técnica de suavização do contorno por mínimos quadrados. Aspectos gráficos são abordados na criação do pré e pós processador, sendo o pré-processador um interpretador de arquivos de formato dxf e o pós-processador destinado a representação gráfica dos resultados através de mapas e isolinhas de tensão, deformação e deslocamentos. / In this work, the boundary element method - BEM, for two-dimensional elasticity, is used to analyse reinforced domains. The rigidity stiffener contribution are taking into account by two different ways: the first one by the sub-region technique or BEM/BEM coupling, and the second one, also based on BEM/BEM coupling, but now considering the variables defined along the central line of the stiffer. Analytical expressions were found to perform the integrals along boundary and interface elements, providing very good results characterized by the elimination of some perturbations that might occur when using stiffener with small rigidity. In order to obtains better and smooth results the least square method was used. Pre- and post-processors were developed and implemented for visualization of the input data and the final results. The pre-processor was written as a dxf reader program, while the post-processor as a counter map stress, strain and displacement iso-lines.
3

Programming paradigms, information types and graphical representations : empirical investigations of novice program comprehension

Good, Judith January 1999 (has links)
This thesis describes research into the role of various factors in novice program comprehension, including the underlying programming paradigm, the representational features of the programming language, and the various types of information which can be derived from the program. The main postulate of the thesis is that there is no unique method for understanding programs, and that program comprehension will be influenced by, among other things, the way in which programs are represented, both semantically and syntactically. This idea has implications for the learning of programming, particularly in terms of how theses concepts should be embodied. The thesis is focused around three empirical studies. The first study, based on th so-called "information types" studies, challenged the idea that program comprehension is an invariant process over languages, and suggested that programming language will have a differential effect on comprehension, as evidenced by the types of information which novices are able to extract from a program. Despite the use of a markedly different language from earliier studies, the results were broadly similar. However, it was suggested that there are other factors additional to programming notation which intervene in the comprehension process, and which cannot be discounted. Furthermore, the study highlighted the need to tie the hypotheses about information extraction more closely to the programming paradigm. The second study introduced a graphical component into the investigation, and looked at the way in which visual representations of programs combine with programming paradigm to influence comprehension. The mis-match conjecture, which suggests that tasks requiring information which is highlighted by a notation will be facilitated relative to tasks where the information must be inferred, was applied to programming paradigm. The study showed that the mis-match effect can be overridden by other factors, most notably subjects' prior experience and the programming culture in which they are taught. The third study combined the methodologies of the first two studies to look at the mis-match conjecture within the wider context of information types. Using graphical representations of the control flow and data flow paradigms, it showed that, despite a bias toward one paradigm based on prior experience and culture, programming paradigm does influence the way in which the program is understood, resulting in improved performance on tasks requiring information which the paradigm is hypothesised to highlight. Furthermore, this effect extends to groups of information which could be said to be theoretically related to the information being highlighted. The thesis also proposes a new and more precise methodology for the analysis of students' accounts of their comprehension of a program, a form a data which is typically derived from the information types studies. It then shows how an analysis of this qualitative data can be used to provide further support for the quantitative results. Finally, the thesis suggests how the core results could be used to develop computer based support environments for novice visual programming, and provides other suggestions for further work.
4

Representação geométrica de intervalos / Graphical approach to intervals

Franciosi, Beatriz Regina Tavares January 1999 (has links)
Neste trabalho e apresentada uma nova abordagem para a representação gráfica de intervalos. Segundo esta abordagem é possível realizar a análise visual de intervalos a partir da associação entre propriedades geométricas do piano cartesiano e de conjuntos de intervalos representados como pontos desse piano. Esta nova abordagem possibilita a representação da interpretação dual de intervalos, assim como a analise visual de relacionamentos em (IR, <=) e (IR, C). Neste contexto, a representação gráfica do conjunto de intervalos degenerados, representado pela reta y = x, constitui um caso especial desta representação,"o. Por sua vez, a relação (IR, representada pelo semiplano superior a reta y = x, denotado piano IR. A interpretação visual de operações intervalares é obtida diretamente através da aplicação da representação gráfica proposta. Além disto, operandos e operadores podem ser estudados diretamente a partir desta representação. Foram desenvolvidos experimentos de analise visual de intervalos utilizando a abordagem proposta e resultados bastante promissores foram obtidos. Estes experimentos possibilitaram a identificação de novas propriedades de intervalos assim como interpretações não usuais para operações intervalares. Esta representação pode ser utilizada também para observar o comportamento de seqüências de intervalos gerados a partir de programas baseado na aplicação da aritmética intervalar. Nesta caso, pode ser observado como os intervalos desta seqüência variam com relação ao seu ponto médio e o raio, assim como a relação entre eles. Esta representação foi utilizada com sucesso para obter a solução geométrica da equação intervalar afim e efetuando sua validação. Finalmente, analisamos a contribuição efetiva deste trabalho no contexto da aritmética intervalar. / This thesis presents a framework enabling the visual analysis of intervals, obtained by mapping geometric properties of the cartesian plane into interval sets to obtain a graphical representation. This new approach makes possible a dual interval representation and the immediate visual analysis of several relationships in (IR, <=) and (IR, C). In this sense, the set of degenerated intervals is a special case of this approach as they are represented by the straight line y=x. In turn, the order relation in (IR, C) is represented through the half-plane above the straight line y = x, denoted IR plane. Applying this framework, the visual interpretation of most interval operations is obtained directly from the graphical representation of the operands and the operations being studied. On the other hand, some experiments on interval visual analysis were developed with good final results. Thus, new properties and unusual interpretations for known operations can be developed with rather small effort. Moreover, this representation can be easily embedded into a running algorithm, to observe convergence and behavior of interval iterations, as one can easily see how intervals change with respect to midpoint and radius, as well as with respect to each other. The validation of this new approach was carried through the geometric solution of linear interval equations. This result was analyzed in order to verify the effective contribution of this geometrical representation in the context of interval arithmetic.
5

Representação geométrica de intervalos / Graphical approach to intervals

Franciosi, Beatriz Regina Tavares January 1999 (has links)
Neste trabalho e apresentada uma nova abordagem para a representação gráfica de intervalos. Segundo esta abordagem é possível realizar a análise visual de intervalos a partir da associação entre propriedades geométricas do piano cartesiano e de conjuntos de intervalos representados como pontos desse piano. Esta nova abordagem possibilita a representação da interpretação dual de intervalos, assim como a analise visual de relacionamentos em (IR, <=) e (IR, C). Neste contexto, a representação gráfica do conjunto de intervalos degenerados, representado pela reta y = x, constitui um caso especial desta representação,"o. Por sua vez, a relação (IR, representada pelo semiplano superior a reta y = x, denotado piano IR. A interpretação visual de operações intervalares é obtida diretamente através da aplicação da representação gráfica proposta. Além disto, operandos e operadores podem ser estudados diretamente a partir desta representação. Foram desenvolvidos experimentos de analise visual de intervalos utilizando a abordagem proposta e resultados bastante promissores foram obtidos. Estes experimentos possibilitaram a identificação de novas propriedades de intervalos assim como interpretações não usuais para operações intervalares. Esta representação pode ser utilizada também para observar o comportamento de seqüências de intervalos gerados a partir de programas baseado na aplicação da aritmética intervalar. Nesta caso, pode ser observado como os intervalos desta seqüência variam com relação ao seu ponto médio e o raio, assim como a relação entre eles. Esta representação foi utilizada com sucesso para obter a solução geométrica da equação intervalar afim e efetuando sua validação. Finalmente, analisamos a contribuição efetiva deste trabalho no contexto da aritmética intervalar. / This thesis presents a framework enabling the visual analysis of intervals, obtained by mapping geometric properties of the cartesian plane into interval sets to obtain a graphical representation. This new approach makes possible a dual interval representation and the immediate visual analysis of several relationships in (IR, <=) and (IR, C). In this sense, the set of degenerated intervals is a special case of this approach as they are represented by the straight line y=x. In turn, the order relation in (IR, C) is represented through the half-plane above the straight line y = x, denoted IR plane. Applying this framework, the visual interpretation of most interval operations is obtained directly from the graphical representation of the operands and the operations being studied. On the other hand, some experiments on interval visual analysis were developed with good final results. Thus, new properties and unusual interpretations for known operations can be developed with rather small effort. Moreover, this representation can be easily embedded into a running algorithm, to observe convergence and behavior of interval iterations, as one can easily see how intervals change with respect to midpoint and radius, as well as with respect to each other. The validation of this new approach was carried through the geometric solution of linear interval equations. This result was analyzed in order to verify the effective contribution of this geometrical representation in the context of interval arithmetic.
6

Formulação do método dos elementos de contorno para análise de chapas com enrijecedores / Formulation of the boundary elements method for analysis of stiffned plates

Wilson Wesley Wutzow 23 May 2003 (has links)
Neste trabalho, a formulação linear do método dos elementos de contorno - MEC, para elasticidade bidimensional, é empregada para estudo de domínios enrijecidos sendo os enrijecedores abordados de duas formas, a primeira muito conhecida trata-se da técnica de sub-região ou acoplamento MEC/MEC e a segunda também pelo mesmo tipo de acoplamento, mas agora condensando-se as variáveis do contorno para a linha central do enrijecedor. Esta técnica juntamente com a integração completamente analítica dos termos da equação Somigliana proporcionam bons resultados eliminando perturbações em enrijecedores finos. Com o intuito de obter melhores resultados aplica-se ainda a técnica de suavização do contorno por mínimos quadrados. Aspectos gráficos são abordados na criação do pré e pós processador, sendo o pré-processador um interpretador de arquivos de formato dxf e o pós-processador destinado a representação gráfica dos resultados através de mapas e isolinhas de tensão, deformação e deslocamentos. / In this work, the boundary element method - BEM, for two-dimensional elasticity, is used to analyse reinforced domains. The rigidity stiffener contribution are taking into account by two different ways: the first one by the sub-region technique or BEM/BEM coupling, and the second one, also based on BEM/BEM coupling, but now considering the variables defined along the central line of the stiffer. Analytical expressions were found to perform the integrals along boundary and interface elements, providing very good results characterized by the elimination of some perturbations that might occur when using stiffener with small rigidity. In order to obtains better and smooth results the least square method was used. Pre- and post-processors were developed and implemented for visualization of the input data and the final results. The pre-processor was written as a dxf reader program, while the post-processor as a counter map stress, strain and displacement iso-lines.
7

Representação geométrica de intervalos / Graphical approach to intervals

Franciosi, Beatriz Regina Tavares January 1999 (has links)
Neste trabalho e apresentada uma nova abordagem para a representação gráfica de intervalos. Segundo esta abordagem é possível realizar a análise visual de intervalos a partir da associação entre propriedades geométricas do piano cartesiano e de conjuntos de intervalos representados como pontos desse piano. Esta nova abordagem possibilita a representação da interpretação dual de intervalos, assim como a analise visual de relacionamentos em (IR, <=) e (IR, C). Neste contexto, a representação gráfica do conjunto de intervalos degenerados, representado pela reta y = x, constitui um caso especial desta representação,"o. Por sua vez, a relação (IR, representada pelo semiplano superior a reta y = x, denotado piano IR. A interpretação visual de operações intervalares é obtida diretamente através da aplicação da representação gráfica proposta. Além disto, operandos e operadores podem ser estudados diretamente a partir desta representação. Foram desenvolvidos experimentos de analise visual de intervalos utilizando a abordagem proposta e resultados bastante promissores foram obtidos. Estes experimentos possibilitaram a identificação de novas propriedades de intervalos assim como interpretações não usuais para operações intervalares. Esta representação pode ser utilizada também para observar o comportamento de seqüências de intervalos gerados a partir de programas baseado na aplicação da aritmética intervalar. Nesta caso, pode ser observado como os intervalos desta seqüência variam com relação ao seu ponto médio e o raio, assim como a relação entre eles. Esta representação foi utilizada com sucesso para obter a solução geométrica da equação intervalar afim e efetuando sua validação. Finalmente, analisamos a contribuição efetiva deste trabalho no contexto da aritmética intervalar. / This thesis presents a framework enabling the visual analysis of intervals, obtained by mapping geometric properties of the cartesian plane into interval sets to obtain a graphical representation. This new approach makes possible a dual interval representation and the immediate visual analysis of several relationships in (IR, <=) and (IR, C). In this sense, the set of degenerated intervals is a special case of this approach as they are represented by the straight line y=x. In turn, the order relation in (IR, C) is represented through the half-plane above the straight line y = x, denoted IR plane. Applying this framework, the visual interpretation of most interval operations is obtained directly from the graphical representation of the operands and the operations being studied. On the other hand, some experiments on interval visual analysis were developed with good final results. Thus, new properties and unusual interpretations for known operations can be developed with rather small effort. Moreover, this representation can be easily embedded into a running algorithm, to observe convergence and behavior of interval iterations, as one can easily see how intervals change with respect to midpoint and radius, as well as with respect to each other. The validation of this new approach was carried through the geometric solution of linear interval equations. This result was analyzed in order to verify the effective contribution of this geometrical representation in the context of interval arithmetic.
8

[en] HOW TO REPRESENT THE PRODUCT DESIGN: ORDINARY AND COMPUTER GRAPHICS WAYS / [pt] A REPRESENTAÇÃO DO PROJETO DE PRODUTO: MEIOS TRADICIONAIS E O USO DA COMPUTAÇÃO GRÁFICA

HELENA CAVALCANTI DE ALBUQUERQUE 27 November 2003 (has links)
[pt] Representações gráficas bidimensionais - tais como o desenho - e modelos tridimensionais físicos (maquetes, mock- ups ou protótipos) são recursos tradicionalmente utilizados por designers para comunicar a idéia de um projeto. Com a crescente inserção do computador no cotidiano e o desenvolvimento do CAD (Computer Aided Design), as áreas projetuais ganharam mais um recurso de representação gráfica: o desenho auxiliado por computador. Diante deste panorama, esta pesquisa procurou investigar junto a alunos e professores do curso de Desenho Industrial com Habilitação em Projeto de Produto do Departamento de Artes e Design da PUC-Rio como se dá a representação e apresentação de seus projetos. A partir da análise do discurso dos entrevistados verificou-se a necessidade de se investigar não só como as diferentes habilidades e processos de representação bidimensional e tridimensional da idéia são utilizadas em paralelo, tais como a habilidade em desenhar à mão, a elaboração de modelos físicos, e a modelagem digital, mas também de se dar o devido destaque ao questionamento, por parte dos entrevistados, da estrutura curricular atual do curso, e sua demanda por novas frentes de atuação da disciplina de Computação Gráfica, de forma a permitir maior capacitação profissional aos alunos de projeto de produto. / [en] Two-dimensional graphic representation - such as drawings - and physical three-dimensional models - such as mock-ups and prototypes - are resources traditionally used by designers to communicate the idea of a project. With the growth of computer use and the development of CAD (Computer Aided Design), project areas gained one more graphic representation resource. Considering this scenario, this research work has investigated how Product Design students at Pontificia Universidade Católica in Rio de Janeiro do the representation and presentation of their projects. The research was based on interviews with teachers and students and concluded that both human varied capabilities and two- dimensional or three-dimensional representation are relevant - hand drawing ability, drawing practice, physical models manufacturing and digital modeling are equally important. It was also verified that there is a strong aspiration between the interviewees for a revision of the present course structure and for the development of new areas of Computer Graphics utilization, so that the Product Design students can achieve a better level of professional capability.
9

Chemical sense marks : expanding the boundaries of registrability frequent concerns when applying for registration at the office for harmonisation in the internal market (trade marks and designs) (OHIM)

Covarrubia, Patricia January 2010 (has links)
The harmonisation of the European Trade Mark laws and the introduction of unconventional marks under this regime have encouraged interested parties to seek registration of chemical senses (scent and taste) as trade marks. This thesis studies the current state of affairs of these types of marks. It discusses in general, the panorama that these types of marks have when registrability is at issue. The purpose of this research is therefore to scrutinise the trade mark legal system, including a discussion of the origins and rationale underlying it, to try to understand the burdens presented when registering chemical sense marks. The starting point of this thesis is that the European Regulation and the Directive of the Trade Mark law open the door to the protection of chemical senses under the Trade Mark law regime. Yet, despite some early successful registration, their fate is still burdened with uncertainty and therefore the rationale for this study is to try to find whether chemical sense marks are truly marks and therefore protectable under the trade mark system. The approach chosen addresses the examination of all requirements for a sign to be protected under the trade mark system. The reason is that protection of chemical senses might be granted if such marks are recognised as signs, are graphically represented and are capable of distinguishing products of one undertaking from those of another undertaking. By examining the aforementioned requirements, the study reveals that while chemical senses marks might be seen as marks, they find that registration is not quite feasible. The thesis emphasises that graphic representation is only one of the many issues that chemical sense marks are confronted with. Issues such as distinctiveness, the need to keep free and functionality remain problematic. Moreover, the scope of protection afforded to chemical sense marks are yet untested. Case law will ascertain that the intent behind the trade mark regime to grant registration to chemical senses is unresolved. Still, the significant interest in chemical senses as trade marks appears to be not softening by this notion.
10

As unidades ambientais da bacia do rio Buquira - SP: um estudo integrado / Mapping of the environmental units of Buquira\'s River Basin in the State of São Paulo

Lameira, Wanja Janayna de Miranda 02 June 2009 (has links)
O século XX marca um período de intensas mudanças nos métodos e nas práticas científicas, face aos novos desafios vividos pela sociedade contemporânea, como a industrialização, crescimento demográfico, expansão urbana e a perda da biodiversidade. Esta nova tendência do cenário mundial faz com que a compreensão do espaço deixe de ser meramente descritiva e independente da participação da sociedade. No âmbito da Geografia, um dos caminhos adotados para tratar estas questões é o conceito de Paisagem fundamentado na teoria dos Geossistemas como orientação viável para o desenvolvimento de pesquisas fundamentais (acadêmicas) e experimentais (aplicadas). No Brasil, uma área que chama atenção pela intensa concentração populacional e a quase extinção da cobertura vegetal é a região do Vale do Rio Paraíba do Sul, face seu histórico de ocupação que, ao longo do tempo, lhe atribuiu um papel singular no cenário econômico nacional. Diante destas premissas, o objetivo da pesquisa foi identificar e caracterizar as unidades ambientais da Bacia do Rio Buquira no Estado de São Paulo, relacionando os aspectos da sociedade e da natureza mediante a elaboração de mapas analíticos que desembocaram num mapa de síntese, como uma etapa no processo do conhecimento. / The XXth Century marks a period of intense change in the methods and scientific practices, meet the new challenges faced by contemporary society, such as industrialization, demographic increasing, urban expansion and loss of biodiversity. In this new trend of world scenario makes understanding of space is no longer seen only in a descriptive way and independent of participation of society. In the scope of Science one theme may allow a reflection about Environmental from the analysis of social organizations allied to a healthy environment is the Geography has the use of landscape concept on the theory of Geossistemas as viable guide for the development of fundamental research (academic) and experimental (applied). In Brazil, an area need care when you think the environmental problems is the Paraiba do Sul River Basin because its history of occupation, which has experienced several economic cycles that gives a major economic role in the national scene in the opposite way, presents a compromising environmental quality. Due to these reasons this work has objective the identification and characterization of environmental units of Buquira`s River Basin in the State of São Paulo, related the social and natural aspects to the space through the development of analytic maps that ran into a synthesis maps one as a step in the knowledge process.

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