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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

Efficient Query Processing Over Large Road-Network Graphs

Rai, Niranjan 22 April 2022 (has links)
No description available.
2

Mapas e redes conceituais: uma proposta metodológica para a sua construção a partir de textos / Maps and conceptual networks: a methodological proposal for its construction from texts

Silva, Patricia Andrade da 07 November 2012 (has links)
A elaboração de textos por alunos em resposta a questões dissertativas dentro do contexto escolar parece ser a forma mais convencional de se tentar avaliar o que os alunos sabem. O texto que um indivíduo produz procura refletir de forma aproximada a sua estrutura de conhecimentos sobre determinado tema. A leitura e análise de textos são tarefas que exigem um tempo considerável no dia-a-dia de um professor ou pesquisador e, quando há o interesse em conhecer as ideias mais relevantes sobre determinado tema para um grupo de alunos, a tarefa é ainda mais trabalhosa. O principal objetivo desta pesquisa consiste em desenvolver uma metodologia que utiliza ferramentas computacionais para transformar textos escritos por alunos em estruturas gráficas como mapas e redes de conceitos. A utilidade desta metodologia aparece tanto no contexto da pesquisa em ensino quanto na própria prática docente, já que o produto final de sua aplicação pode permitir estabelecer inferências quanto à estrutura de conhecimentos de um grupo de alunos. A investigação ocorreu a partir de dados coletados em duas disciplinas distintas de cursos de graduação do IQ-USP. Os dados coletados referem-se a produções textuais de 42 estudantes em resposta a uma questão que fornecia alguns conceitos pré-estabelecidos. A partir das respostas dos alunos foram realizados testes: (i) com dois softwares de análise de textos para a quantificação das relações entre conceitos; (ii) para verificar a influência na quantificação das relações entre conceitos partindo-se do texto como foi escrito e das proposições extraídas do mesmo e (iii) para a obtenção de diferentes tipos de estruturas gráficas. A partir dos testes realizados, foi possível concluir que o programa Hamlet® é mais eficiente e prático do que o programa ALA-Reader® para os objetivos da presente pesquisa. Além disso, a matriz gerada pelo Hamlet® para quantificar as relações entre conceitos depende essencialmente da estrutura do texto em questão - texto original ou texto modificado. Os três tipos de estruturas gráficas construídos apresentam diferentes focos, porém, podem ser considerados complementares. As redes V+P se mostraram interessantes para análises centradas nos conceitos pré-estabelecidos e fornecidos na questão que originou os textos dos alunos. As redes a partir de corte percentual apresentaram-se como representações bastante úteis para investigações interessadas em fazer um recorte ou destacar os aspectos considerados mais relevantes pelos alunos sobre determinado tema. Os mapas conceituais construídos neste trabalho mostraram-se como representações extremamente valiosas para conhecer a aproximada estrutura de conhecimentos dos grupos de alunos, uma vez que explicitam a natureza das relações proposicionais entre os conceitos. A construção de mapas conceituais partindo-se tanto dos textos originais quanto dos textos modificados permitiu concluir que as estruturas gráficas obtidas dos dois modos se aproximam bastante uma da outra, apresentando alta semelhança. Esta semelhança sugere que a utilização do programa Hamlet® para a obtenção de matrizes que quantificam relações entre conceitos presentes em um texto na forma como foi escrito é eficiente quando comparada ao processo manual e mais demorado de se extraírem proposições de um texto para obter uma matriz. / The drafting of essays by students in response to essay questions in the school context seems to be the most conventional way to assess the students` knowledge. The essay produced by a student seeks to approximately reflect his/her knowledge structure about a certain domain. The reading and the analysis of essays are tasks that require a considerable time in a teacher\'s or researcher\'s routine and, when the interest on knowing the most important ideas about a certain topic is verified in a group of students, the task is even harder. The main objective of this research is to develop a methodology that uses computational tools in order to transform written essays in graphic structures such as concept maps and networks graphs. This methodology could be useful not only for teaching research purposes but also for teaching practice, since the final product of its application may lead to inferences about the knowledge structure of a group of students. The investigation developed herein was based on data collected from two distinct matters of undergraduate IQ-USP. That data refer to written essays of 42 students in response to an essay question provided of some pre-established concepts. From the students\' responses, tests were performed: (i) with two softwares for text analysis with a view of quantifying the relationships between concepts, (ii) to investigate the influence on the quantification of relationships between concepts, from the original text and from the propositions extracted from this original text and (iii) to obtain different types of graphic structures. From the tests that were done, it was possible to conclude that Hamlet® consists in a more efficient and convenient program than ALA-Reader® to the objectives of this research. Furthermore, the array generated by Hamlet® program to quantify the relationships between concepts depends essentially on the structure of the essay - either the original text or the modified text. The three types of graphic structures that were built present different focuses, however, these graphic structures may be considered complementaries. The (V+P) network graphs can be thought as interesting representations that focuses on pre-established concepts that were provided on the essay questions. Network graphs from cutting percentage can be thought as representations that are more useful for investigations interested in making a cut or in highlighting the most relevant aspects of a subject by the students. The concept maps constructed in this paper can be thought as extremely valuable representations to know the approximate knowledge structure of the students groups, since they make clear the nature of the propositional relationships between concepts. The construction of concept maps starting from the original texts and also from the modified texts proved that both graphic structures obtained are very close to each other, being highly similar. This similarity suggests that the use of the Hamlet® program to obtain arrays that quantify relationship between concepts found in an original text is more effective in comparison to manual and time-consuming process of extracting propositions from the original text to obtain an array.
3

Mapas e redes conceituais: uma proposta metodológica para a sua construção a partir de textos / Maps and conceptual networks: a methodological proposal for its construction from texts

Patricia Andrade da Silva 07 November 2012 (has links)
A elaboração de textos por alunos em resposta a questões dissertativas dentro do contexto escolar parece ser a forma mais convencional de se tentar avaliar o que os alunos sabem. O texto que um indivíduo produz procura refletir de forma aproximada a sua estrutura de conhecimentos sobre determinado tema. A leitura e análise de textos são tarefas que exigem um tempo considerável no dia-a-dia de um professor ou pesquisador e, quando há o interesse em conhecer as ideias mais relevantes sobre determinado tema para um grupo de alunos, a tarefa é ainda mais trabalhosa. O principal objetivo desta pesquisa consiste em desenvolver uma metodologia que utiliza ferramentas computacionais para transformar textos escritos por alunos em estruturas gráficas como mapas e redes de conceitos. A utilidade desta metodologia aparece tanto no contexto da pesquisa em ensino quanto na própria prática docente, já que o produto final de sua aplicação pode permitir estabelecer inferências quanto à estrutura de conhecimentos de um grupo de alunos. A investigação ocorreu a partir de dados coletados em duas disciplinas distintas de cursos de graduação do IQ-USP. Os dados coletados referem-se a produções textuais de 42 estudantes em resposta a uma questão que fornecia alguns conceitos pré-estabelecidos. A partir das respostas dos alunos foram realizados testes: (i) com dois softwares de análise de textos para a quantificação das relações entre conceitos; (ii) para verificar a influência na quantificação das relações entre conceitos partindo-se do texto como foi escrito e das proposições extraídas do mesmo e (iii) para a obtenção de diferentes tipos de estruturas gráficas. A partir dos testes realizados, foi possível concluir que o programa Hamlet® é mais eficiente e prático do que o programa ALA-Reader® para os objetivos da presente pesquisa. Além disso, a matriz gerada pelo Hamlet® para quantificar as relações entre conceitos depende essencialmente da estrutura do texto em questão - texto original ou texto modificado. Os três tipos de estruturas gráficas construídos apresentam diferentes focos, porém, podem ser considerados complementares. As redes V+P se mostraram interessantes para análises centradas nos conceitos pré-estabelecidos e fornecidos na questão que originou os textos dos alunos. As redes a partir de corte percentual apresentaram-se como representações bastante úteis para investigações interessadas em fazer um recorte ou destacar os aspectos considerados mais relevantes pelos alunos sobre determinado tema. Os mapas conceituais construídos neste trabalho mostraram-se como representações extremamente valiosas para conhecer a aproximada estrutura de conhecimentos dos grupos de alunos, uma vez que explicitam a natureza das relações proposicionais entre os conceitos. A construção de mapas conceituais partindo-se tanto dos textos originais quanto dos textos modificados permitiu concluir que as estruturas gráficas obtidas dos dois modos se aproximam bastante uma da outra, apresentando alta semelhança. Esta semelhança sugere que a utilização do programa Hamlet® para a obtenção de matrizes que quantificam relações entre conceitos presentes em um texto na forma como foi escrito é eficiente quando comparada ao processo manual e mais demorado de se extraírem proposições de um texto para obter uma matriz. / The drafting of essays by students in response to essay questions in the school context seems to be the most conventional way to assess the students` knowledge. The essay produced by a student seeks to approximately reflect his/her knowledge structure about a certain domain. The reading and the analysis of essays are tasks that require a considerable time in a teacher\'s or researcher\'s routine and, when the interest on knowing the most important ideas about a certain topic is verified in a group of students, the task is even harder. The main objective of this research is to develop a methodology that uses computational tools in order to transform written essays in graphic structures such as concept maps and networks graphs. This methodology could be useful not only for teaching research purposes but also for teaching practice, since the final product of its application may lead to inferences about the knowledge structure of a group of students. The investigation developed herein was based on data collected from two distinct matters of undergraduate IQ-USP. That data refer to written essays of 42 students in response to an essay question provided of some pre-established concepts. From the students\' responses, tests were performed: (i) with two softwares for text analysis with a view of quantifying the relationships between concepts, (ii) to investigate the influence on the quantification of relationships between concepts, from the original text and from the propositions extracted from this original text and (iii) to obtain different types of graphic structures. From the tests that were done, it was possible to conclude that Hamlet® consists in a more efficient and convenient program than ALA-Reader® to the objectives of this research. Furthermore, the array generated by Hamlet® program to quantify the relationships between concepts depends essentially on the structure of the essay - either the original text or the modified text. The three types of graphic structures that were built present different focuses, however, these graphic structures may be considered complementaries. The (V+P) network graphs can be thought as interesting representations that focuses on pre-established concepts that were provided on the essay questions. Network graphs from cutting percentage can be thought as representations that are more useful for investigations interested in making a cut or in highlighting the most relevant aspects of a subject by the students. The concept maps constructed in this paper can be thought as extremely valuable representations to know the approximate knowledge structure of the students groups, since they make clear the nature of the propositional relationships between concepts. The construction of concept maps starting from the original texts and also from the modified texts proved that both graphic structures obtained are very close to each other, being highly similar. This similarity suggests that the use of the Hamlet® program to obtain arrays that quantify relationship between concepts found in an original text is more effective in comparison to manual and time-consuming process of extracting propositions from the original text to obtain an array.
4

Arrangements 2D pour la Cartographie de l’Espace Public et des Transports / 2D Arrangements for Public Space Mapping and Transportation

Yirci, Murat 15 April 2016 (has links)
Cette thèse porte sur le développement facilité d'applications de cartographie et de transport, plus particulièrement sur la génération de réseaux piétonniers pour des applications telles que la navigation, le calcul d'itinéraires, l'analyse d'accessibilité et l'urbanisme. Afin d'atteindre ce but, nous proposons un modèle de données à deux couches qui cartographie l'espace public dans une hiérarchie d'objets géospatiaux sémantisés. A bas niveau, la géométrie 2D des objets géospatiaux est représentée par une partition planaire, modélisée par une structure topologique d'arrangement 2D. Cette représentation permet des traitements géométriques efficaces et efficients, ainsi qu'une maintenance et une validation aisée au fur et à mesure des éditions lorsque la géométrie ou la topologie d'un objet sont modifiées. A haut niveau, les aspects sémantiques et thématiques des objets géospatiaux sont modélisés et gérés. La hiérarchie entre ces objets est maintenue à travers un graphe dirigé acyclique dans lequel les feuilles correspondent à des primitives géométriques de l'arrangement 2D et les noeuds de plus haut niveau représentent les objets géospatiaux sémantiques plus ou moins aggrégés. Nous avons intégré le modèle de données proposé dans un framework SIG nommé StreetMaker en complément d'un ensemble d'algorithmes génériques et de capacités SIG basiques. Ce framework est alors assez riche pour générer automatiquement des graphes de réseau piétonnier. En effet, dans le cadre d'un projet d'analyse d'accessibilité, le flux de traitement proposé a permis de produire avec succès sur deux sites un graphe de réseau piétonnier à partir de données en entrées variées : des cartes vectorielles existantes, des données vectorielles créées semi-automatiquement et des objets vectoriels extraits d'un nuage de points lidar issu d'une acquisition de cartographie mobile.Alors que la modélisation 2D de la surface du sol est suffisante pour les applications SIG 2D, les applications SIG 3D nécessitent des modèles 3D de l'environnement. La modélisation 3D est un sujet très large mais, dans un premier pas vers cette modélisation 3D, nous nous sommes concentrés sur la modélisation semi-automatique d'objets de type cylindre généralisé (tels que les poteaux, les lampadaires, les troncs d'arbre, etc) à partir d'une seule image. Les méthodes et techniques développées sont présentées et discutées / This thesis addresses easy and effective development of mapping and transportation applications which especially focuses on the generation of pedestrian networks for applications like navigation, itinerary calculation, accessibility analysis and urban planning. In order to achieve this goal, we proposed a two layered data model which encodes the public space into a hierarchy of semantic geospatial objects. At the lower level, the 2D geometry of the geospatial objects are captured using a planar partition which is represented as a topological 2D arrangement. This representation of a planar partition allows efficient and effective geometry processing and easy maintenance and validation throughout the editions when the geometry or topology of an object is modified. At the upper layer, the semantic and thematic aspects of geospatial objects are modelled and managed. The hierarchy between these objects is maintained using a directed acyclic graph (DAG) in which the leaf nodes correspond to the geometric primitives of the 2D arrangement and the higher level nodes represent the aggregated semantic geospatial objects at different levels. We integrated the proposed data model into our GIS framework called StreetMaker together with a set of generic algorithms and basic GIS capabilities. This framework is then rich enough to generate pedestrian network graphs automatically. In fact, within an accessibility analysis project, the full proposed pipeline was successfully used on two sites to produce pedestrian network graphs from various types of input data: existing GIS vector maps, semi-automatically created vector data and vector objects extracted from Mobile Mapping lidar point clouds.While modelling 2D ground surfaces may be sufficient for 2D GIS applications, 3D GIS applications require 3D models of the environment. 3D modelling is a very broad topic but as a first step to such 3D models, we focused on the semi-automatic modelling of objects which can be modelled or approximated by generalized cylinders (such as poles, lampposts, tree trunks, etc.) from single images. The developed methods and techniques are presented and discussed
5

Network Based Tools and Indicators for Landscape Ecological Assessments, Planning, and Design

Zetterberg, Andreas January 2009 (has links)
<p>Land use change constitutes a primary driving force in shaping social-ecological systems world wide, and its effects reach far beyond the directly impacted areas. Graph based landscape ecological tools have become established as a promising way to efficiently explore and analyze the complex, spatial systems dynamics of ecological networks in physical landscapes. However, little attention has been paid to making these approaches operational within ecological assessments, physical planning, and design. This thesis presents a network based, landscape-ecological tool that can be implemented for effective use by practitioners within physical planning and design, and ecological assessments related to these activities. The tool is based on an ecological profile system, a common generalized network model of the ecological infrastructure, graph theoretic metrics, and a spatially explicit, geographically defined representation, deployable in a GIS. Graph theoretic metrics and analysis techniques are able to capture the spatio-temporal dynamics of complex systems, and the generalized network model places the graph theoretic toolbox in a geographically defined landscape. This provides completely new insights for physical planning, and environmental assessment activities. The design of the model is based on the experience gained through seven real-world cases, commissioned by different governmental organizations within Stockholm County. A participatory approach was used in these case studies, involving stakeholders of different backgrounds, in which the tool proved to be flexible and effective in the communication and negotiation of indicators, targets, and impacts. In addition to successful impact predictions for alternative planning scenarios, the tool was able to highlight critical ecological structures within the landscape, both from a system-centric, and a site-centric perspective. In already being deployed and used in planning, assessments, inventories, and monitoring by several of the involved organizations, the tool has proved to effectively meet some of the challenges of application in a multidisciplinary landscape.</p>
6

Network Based Tools and Indicators for Landscape Ecological Assessments, Planning, and Design

Zetterberg, Andreas January 2009 (has links)
Land use change constitutes a primary driving force in shaping social-ecological systems world wide, and its effects reach far beyond the directly impacted areas. Graph based landscape ecological tools have become established as a promising way to efficiently explore and analyze the complex, spatial systems dynamics of ecological networks in physical landscapes. However, little attention has been paid to making these approaches operational within ecological assessments, physical planning, and design. This thesis presents a network based, landscape-ecological tool that can be implemented for effective use by practitioners within physical planning and design, and ecological assessments related to these activities. The tool is based on an ecological profile system, a common generalized network model of the ecological infrastructure, graph theoretic metrics, and a spatially explicit, geographically defined representation, deployable in a GIS. Graph theoretic metrics and analysis techniques are able to capture the spatio-temporal dynamics of complex systems, and the generalized network model places the graph theoretic toolbox in a geographically defined landscape. This provides completely new insights for physical planning, and environmental assessment activities. The design of the model is based on the experience gained through seven real-world cases, commissioned by different governmental organizations within Stockholm County. A participatory approach was used in these case studies, involving stakeholders of different backgrounds, in which the tool proved to be flexible and effective in the communication and negotiation of indicators, targets, and impacts. In addition to successful impact predictions for alternative planning scenarios, the tool was able to highlight critical ecological structures within the landscape, both from a system-centric, and a site-centric perspective. In already being deployed and used in planning, assessments, inventories, and monitoring by several of the involved organizations, the tool has proved to effectively meet some of the challenges of application in a multidisciplinary landscape.

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