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Fractal or Scaling Analysis of Natural Cities Extracted from Open Geographic Data SourcesHUANG, KUAN-YU January 2015 (has links)
A city consists of many elements such as humans, buildings, and roads. The complexity of cities is difficult to measure using Euclidean geometry. In this study, we use fractal geometry (scaling analysis) to measure the complexity of urban areas. We observe urban development from different perspectives using the bottom-up approach. In a bottom-up approach, we observe an urban region from a basic to higher level from our daily life perspective to an overall view. Furthermore, an urban environment is not constant, but it is complex; cities with greater complexity are more prosperous. There are many disciplines that analyze changes in the Earth’s surface, such as urban planning, detection of melting ice, and deforestation management. Moreover, these disciplines can take advantage of remote sensing for research. This study not only uses satellite imaging to analyze urban areas but also uses check-in and points of interest (POI) data. It uses straightforward means to observe an urban environment using the bottom-up approach and measure its complexity using fractal geometry. Web 2.0, which has many volunteers who share their information on different platforms, was one of the most important tools in this study. We can easily obtain rough data from various platforms such as the Stanford Large Network Dataset Collection (SLNDC), the Earth Observation Group (EOG), and CloudMade. The check-in data in this thesis were downloaded from SLNDC, the POI data were obtained from CloudMade, and the nighttime lights imaging data were collected from EOG. In this study, we used these three types of data to derive natural cities representing city regions using a bottom-up approach. Natural cities were derived from open geographic data without human manipulation. After refining data, we used rough data to derive natural cities. This study used a triangulated irregular network to derive natural cities from check-in and POI data. In this study, we focus on the four largest US natural cities regions: Chicago, New York, San Francisco, and Los Angeles. The result is that the New York City region is the most complex area in the United States. Box-counting fractal dimension, lacunarity, and ht-index (head/tail breaks index) can be used to explain this. Box-counting fractal dimension is used to represent the New York City region as the most prosperous of the four city regions. Lacunarity indicates the New York City region as the most compact area in the United States. Ht-index shows the New York City region having the highest hierarchy of the four city regions. This conforms to central place theory: higher-level cities have better service than lower-level cities. In addition, ht-index cannot represent hierarchy clearly when data distribution does not fit a long-tail distribution exactly. However, the ht-index is the only method that can analyze the complexity of natural cities without using images.
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Χρήση αλγορίθμων μηχανικής μάθησης για την ταυτοποίηση κοινών σημείων ενδιαφέροντος σε ετερογενή σύνολα δεδομένων από μέσα κοινωνικής δικτύωσηςΚαλαβρουζιώτης, Βασίλειος 02 April 2014 (has links)
Στην εργασία αυτή ασχολούμαστε με την αξιοποίηση των δεδομένων από διαφορετικά κοινωνικά δίκτυα (πιο συγκεκριμένα από Foursquare και Facebook) με σκοπό να ταυτοποιήσουμε τις ίδιες τοποθεσίες (ή αλλιώς σημεία ενδιαφέροντος) που έχουν εισαχθεί σε αυτά τα δίκτυα. Το πρόβλημα της ταυτοποίησης είναι σημαντικό να λυθεί διότι έτσι θα μπορούσε να αποκτηθεί μια καλύτερη εικόνα για τις αλληλεπιδράσεις των χρηστών με το φυσικό περιβάλλον με τη χρήση των μέσων κοινωνικής δικτύωσης (social data). Αυτό σημαίνει ταυτόχρονα και καλύτερη ανάλυση και αξιοποίηση αυτών δεδομένων, αφού θα έχουμε αναγνωρίσει μεγάλο μέρος των κοινών σημείων ενδιαφέροντος από ετερογενή σύνολα δεδομένων από τα μέσα κοινωνικής δικτύωσης.
Μια λύση στο πρόβλημα είναι η χρήση των αλγορίθμων μηχανικής μάθησης, που θα αποφασίζουν αν ένα ζεύγος σημείων αντιπροσωπεύει το ίδιο σημείο ενδιαφέροντος. / In this paper we deal with the exploitation of data from different social networks (more specifically from Foursquare and Facebook) in order to identify the same locations (or landmarks ) introduced in these networks . The problem of identification is important to solve it so he could get a better picture of the user interactions with the natural environment through the use of social media (social data). This means simultaneously and better analysis and use of such data , since we recognize much of the common points of interest from heterogeneous datasets from social media .
One solution to this problem is the use of machine learning algorithms , which will decide whether a pair of points represents the same point of interest .
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SB-Index : um índice espacial baseado em bitmap para data warehouse geográficoSiqueira, Thiago Luís Lopes 26 August 2009 (has links)
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Previous issue date: 2009-08-26 / Universidade Federal de Minas Gerais / Geographic Data Warehouses (GDW) became one of the main technologies used in decision-making processes and spatial analysis since they provide the integration of Data Warehouses, On-Line Analytical Processing and Geographic Information Systems. As a result, a GDW enables spatial analyses together with agile and flexible multidimensional analytical queries over huge volumes of data. On the other hand, there is a challenge in a GDW concerning the query performance, which consists of retrieving data related to ad-hoc spatial query windows and avoiding the high cost of star-joins. Clearly, mechanisms to provide efficient query processing, as index structures, are essential. In this master s thesis, a novel index for GDW is introduced, namely the SB-index, which is based on the Bitmap Join Index and the Minimum Bounding Rectangle. The SB-index inherits the Bitmap Index legacy techniques and introduces them in GDW, as well as it enables support for predefined spatial attribute hierarchies. The SB-index validation was performed through experimental performance tests. Comparisons among the SB-index approach, the star-join aided by R-tree and the star-join aided by GiST indicated that the SB-index significantly improves the elapsed time in query processing from 76% up to 96% with regard to queries defined over the spatial predicates of intersection, enclosure and containment and applied to roll-up and drill-down operations. In addition, the impact of the increase in data volume on the performance was analyzed. The increase did not impair the performance of the SB-index, which highly improved the elapsed time in query processing. Moreover, in this master s thesis there is an experimental investigation on how does the spatial data redundancy affect query response time and storage requirements in a GDW? . Redundant and non-redundant GDW schemas were compared, concluding that redundancy is related to high performance losses. Then, aiming at improving query performance, the SB-index performance was evaluated on the redundant GDW schema. The results pointed out that SB-index significantly improves the elapsed time in query processing from 25% up to 99%. Finally, a specific enhancement of the SB-index was developed in order to deal with spatial data redundancy. With this enhancement, the minimum performance gain observed became 80%. / O Data Warehouse Geográfico (DWG) tornou-se uma das principais tecnologias de suporte à decisão, pois promove a integração de data warehouses, On-Line Analytical Processing e Sistemas de Informações Geográficas. Por isso, um DWG viabiliza a análise espacial aliada à execução de consultas analíticas multidimensionais envolvendo enormes volumes de dados. Por outro lado, existe um desafio relativo ao desempenho no processamento de consultas, que envolvem janelas de consulta espaciais ad-hoc e várias junções entre tabelas. Claramente, mecanismos para aumentar o desempenho do processamento de consultas, como as estruturas de indexação, são essenciais. Nesta dissertação, propõe-se um novo índice para DWG chamado SB-index, baseado no Índice Bitmap de Junção e no Retângulo Envolvente Mínimo. O SB-index herda todo o legado de técnicas do Índice Bitmap e o introduz no DWG. Além disso, ele provê suporte a hierarquias de atributos espaciais predefinidas. Este índice foi validado por meio de testes experimentais de desempenho. Comparações entre o SB-index, a junção estrela auxiliada pela R-tree e a junção-estrela auxiliada por GiST indicaram que o SB-index diminui significativamente o tempo de resposta do processamento de consultas roll-up e drill-down relacionadas aos predicados espaciais intersecta , está contido e contém , promovendo ganhos de 76% a 96%. Mostrou-se ainda que a variação do volume de dados não prejudica o desempenho do SB-index. Esta dissertação também investiga a seguinte questão: como a redundância de dados espaciais afeta um DWG? . Foram comparados os esquemas de DWG redundante e não-redundante. Observou-se que a redundância de dados espaciais acarreta prejuízos ao tempo de resposta das consultas e aos requisitos de armazenamento do DWG. Então, visando melhorar o desempenho do processamento de consultas, introduziu-se o SB-index no esquema de DWG redundante. Os ganhos de desempenho obtidos a partir desta ação variaram de 25% a 99%. Por fim, foi proposta uma melhoria sobre o SB-index a fim de lidar especificamente com a questão da redundância de dados espaciais. A partir desta melhoria, o ganho mínimo de desempenho tornou-se 80%.
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Processamento de consultas SOLAP drill-across e com junção espacial em data warehouses geográficos / Processing of drill-across and spatial join SOLAP queries over geographic data warehousesJaqueline Joice Brito 28 November 2012 (has links)
Um data warehouse geográco (DWG) é um banco de dados multidimensional, orientado a assunto, integrado, histórico, não-volátil e geralmente organizado em níveis de agregação. Além disso, também armazena dados espaciais em uma ou mais dimensões ou em pelo menos uma medida numérica. Visando oferecer suporte à tomada de decisão, é possível realizar em DWGs consultas SOLAP (spatial online analytical processing ), isto é, consultas analíticas multidimensionais (e.g., drill-down, roll-up, drill-across ) com predicados espaciais (e.g., intersecta, contém, está contido) denidos para range queries e junções espaciais. Um desafio no processamento dessas consultas é recuperar, de forma eficiente, dados espaciais e convencionais em DWGs muito volumosos. Na literatura, existem poucos índices voltados à indexação de DWGs, e ainda assim nenhum desses índices dedica-se a indexar consultas SOLAP drill-across e com junção espacial. Esta dissertação visa suprir essa limitação, por meio da proposta de estratégias para o processamento dessas consultas complexas. Para o processamento de consultas SOLAP drill-across foram propostas duas estratégias, Divide e Única, além da especicação de um conjunto de diretrizes que deve ser seguido para o projeto de um esquema de DWG que possibilite a execução dessas consultas e da especicação de classes de consultas. Para o processamento de consultas SOLAP com junção espacial foi proposta a estratégia SJB, além da identicação de quais características o esquema de DWG deve possuir para possibilitar a execução dessas consultas e da especicação do formato dessas consultas. A validação das estratégias propostas foi realizada por meio de testes de desempenho considerando diferentes congurações, sendo que os resultados obtidos foram contrastados com a execução de consultas do tipo junção estrela e o uso de visões materializadas. Os resultados mostraram que as estratégias propostas são muito eficientes. No processamento de consultas SOLAP drill-across, as estratégias Divide e Única mostraram uma redução no tempo de 82,7% a 98,6% com relação à junção estrela e ao uso de visões materializadas. No processamento de consultas SOLAP com junção espacial, a estratégia SJB garantiu uma melhora de desempenho na grande maioria das consultas executadas. Para essas consultas, o ganho de desempenho variou de 0,3% até 99,2% / A geographic data warehouse (GDW) is a special kind of multidimensional database. It is subject-oriented, integrated, historical, non-volatile and usually organized in levels of aggregation. Furthermore, a GDW also stores spatial data in one or more dimensions or at least in one numerical measure. Aiming at decision support, GDWs allow SOLAP (spatial online analytical processing) queries, i.e., multidimensional analytical queries (e.g., drill-down, roll-up, drill-across) extended with spatial predicates (e.g., intersects, contains, is contained) dened for range and spatial join queries. A challenging issue related to the processing of these complex queries is how to recover spatial and conventional data stored in huge GDWs eciently. In the literature, there are few access methods dedicated to index GDWs, and none of these methods focus on drill-across and spatial join SOLAP queries. In this master\'s thesis, we propose novel strategies for processing these complex queries. We introduce two strategies for processing SOLAP drill-across queries (namely, Divide and Unique), dene a set of guidelines for the design of a GDW schema that enables the execution of these queries, and determine a set of classes of these queries to be issued over a GDW schema that follows the proposed guidelines. As for the processing of spatial join SOLAP queries, we propose the SJB strategy, and also identify the characteristics of a DWG schema that enables the execution of these queries as well as dene the format of these queries. We validated the proposed strategies through performance tests that compared them with the star join computation and the use of materialized views. The obtained results showed that our strategies are very ecient. Regarding the SOLAP drill-across queries, the Divide and Unique strategies showed a time reduction that ranged from 82,7% to 98,6% with respect to star join computation and the use of materialized views. Regarding the SOLAP spatial join queries, the SJB strategy guaranteed best results for most of the analyzed queries. For these queries, the performance gain of the SJB strategy ranged from 0,3% to 99,2% over the star join computation and the use of materialized view
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Proposta de um modelo genérico de um SBDE que permita a interoperabilidade entre sistemas / Proposal for a generic model of a SBDE aiming interoperability between systemsFrancisco Roza de Moraes 21 August 2017 (has links)
Os constantes avanços técnico-científicos, nas diversas áreas da engenharia, ocasionaram grandes mudanças nos inúmeros métodos de abordagem do cotidiano e também, realizaram papel fundamental, na aproximação de novos usuários, com ou sem conhecimentos específicos, à utilização das novas técnicas. Na Cartografia, por exemplo, esses avanços e a aproximação de novos usuários, com diferentes necessidades de uso, possibilitaram o desenvolvimento de modernos modos de abordagem para problemas do dia a dia. A criação da estruturação de dados digitais geográficos permitiu o desenvolvimento de novas ferramentas computacionais que, como os Sistemas de Informação Geográficas, agilizaram as etapas referentes aos processos de pesquisas relacionados a utilização de dados geográficos. Contudo, para uma correta utilização das novas ferramentas, os conjuntos de dados geográficos, devem apresentar-se de modo estruturado, seguindo normas e técnicas bem elaboradas sobre esse assunto. Um esforço que, por muitas vezes, não ocorre por parte dos usuários finais que acabada por comprometer toda a eficiência do sistema eletrônico. Este trabalho aborda assim, os benefícios envolvidos na utilização de padrões e técnicas de desenvolvimento de softwares bem definidas e eficientes; as instituições internacionais responsáveis por estabelecerem as regras base e os esforços necessários para o desenvolvimento com qualidade de uma aplicação que utilize banco de dados espaciais. / The constant technical and scientific advances, in various areas of engineering, have led to changes in the many methods of everyday approach and played a fundamental role in attracting new users, with or without specific knowledge, to the use of these new techniques. In cartography, in special, these advances and the approximation of new users, with different skill levels, enabled the development of modern methods for resolution of problems. The creation of data structure for geographic applications allowed the development of new computational tools that, as the Geographic Information Systems, helped the development related to the research processes with geographic data. However, for a correct use of these new tools, spatial databases must be developed in a structured way, following well-developed standards and techniques. An effort that, for many times, does not occur on the part of the end users that end up compromising all the efficiency of the computational system. This work present: The benefits involved in the use of standards and techniques for developing efficient software; showing the international institutions responsible for establishing the base rules and the necessary efforts for the development with quality of an application that uses spatial databases.
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Espacialização dos acidentes de trânsito em Uberlândia (MG): técnicas de geoprocessamento como instrumento de análise - 2000 a 2004 / Spacialization of the traffic accidents in Uberlândia (MG): geoprocessing techniques as analysis instrument - 2000 a 2004Andrea Rispoli Bernardino 03 May 2007 (has links)
Os números de ocorrências em acidentes de trânsito são assustadores. Avalia-se que o custo dos acidentes aproxime de 1% do PIB em países pobres e 2% nas nações desenvolvidas. Em termos globais, são gastos U$ 518 bilhões anuais. No Brasil, estudos apontam que houve uma queda de 20 mil vítimas fatais de acidentes de trânsito, de 1987 para 1998, apresentando, atualmente, em torno de 30 mil mortes/ano no trânsito. Essa redução pode ser em parte justificada pelo Código de Trânsito Brasileiro, que entrou em vigor em 22 de janeiro de 1998. Considerado como um desafio pelos órgãos gestores do planejamento urbano viário, a redução das ocorrências de acidentes de trânsito torna-se um tema discutido, incessantemente, na administração pública. Diante dessa leitura urbana, este estudo propõe conhecer as características dos acidentes de trânsito ocorridos na área urbana da cidade de Uberlândia entre os anos de 2000 e 2004, bem como espacializar as vias, os trechos e os cruzamentos com maior número de acidentes, com o intuito de identificá-los por meio de técnicas disponíveis em BRASIL (2002) e Gold (1998), que, adaptadas ao banco de dados disponíveis pela SETTRAN, determinaram quais são as vias, os trechos e os cruzamentos críticos. Por meio desses procedimentos, apresenta-se a identificação de vinte vias, vinte trechos e vinte cruzamentos que foram palco dos maiores números de acidentes ocorridos no trânsito e dos números mais altos de UPS dos acidentes de trânsito entre os anos de 2000 e 2004. Analisando a situação crítica dos segmentos analisados, as vias descritas a seguir foram consideradas importantes, por estarem enumeradas em todas as seleções hierarquizadas e agrupadas, bem como os trechos e os cruzamentos, sendo as Av. João Naves de Ávila e Av. Rondon Pacheco, seguidas da Av. Afonso Pena e Av. Floriano Peixoto. Para os trechos críticos, estas aparecem como sendo as vias principais e suas interseções mais significativas estão localizadas na área central e vias que dão acesso ao \"shopping center\". Quanto aos cruzamentos, as vias que fazem as interseções com as ora citadas possibilitam conflitos, que, pela alta freqüência dos acidentes de trânsito em um mesmo local, foram estabelecidos os pontos críticos pela significância que os números dos acidentes de trânsito apresentam e de suas especificações do local identificado. Para a redução das relações de conflitos no trânsito, bem como a prevenção de um grande número de ocorrências de acidentes de trânsito, devem ser consideradas medidas de educação que levem os cidadãos a atitudes e comportamentos de convivência ao utilizar o ambiente viário comum aos pedestres e veículos. Assim, o alcance deste objetivo é salutar, pois empenha-se na busca de estratégias que possam otimizar os recursos disponíveis e estabelecer parcerias que garantam a efetividade das estratégias definidas, afugentando esse mal que assola a cidade sem pedir licença / The numbers of traffic accidents occurrences are frightful. It is evaluated that the cost of the accidents is near to 1% of the GIP in poor countries and 2% in the developed nations. In global terms, U$ 518 billion/year are expensed. In Brazil, studies point that there was a fall in 20 thousand of fatal victims in traffic accidents between 1987 and 1998. Currently, we had around 30 thousand deaths/year in the traffic. This reduction can be partly justified for the Brazilian Transit Code, which works since 22 January 1998. Considered a challenge for the managing agencies of the road urban planning, the reduction of the traffic accidents occurrences become a subject incessantly discussed in the public administration. In front of this urban reading, this study proposes to know the characteristics of the traffic accidents occurred in the urban area of the Uberlândia-MG, considering the period 2004-2004, as well to space the streets, the stretches and the crossings with more accidents, intending to identify this streets through techniques available in BRAZIL (2002) and Gold (1998). This procedure was adapted from the available data base by SETTRAN and they had determined which are the critical streets, stretches and crossings in question. By these procedures, we present the identification of twenty streets, twenty stretches and twenty crossings where happens the biggest numbers of transit accidents and the highest numbers of UPS of the traffic accidents between 2000 and 2004. Considering the critical situation of the analyzed segments, the following described streets had been considered important because they are enumerated in all of the ranked and grouped selections, as well as the stretches and the crossings. The streets are: João Naves de Ávila Avenue, Rondon Pacheco Avenue, followed by Afonso Pena Avenue and Floriano Peixoto Avenue. For the critical stretches, these are the main streets and its more significant intersections are located in the central area and streets with access to the \"Shopping Center\". About the crossings, the streets intersected with those streets make possible the conflicts. On account of the high frequency of the traffic accidents in a same local, we established the critical points with basis in the significance that the numbers of the traffic accidents present and specifications presented by the identified place. For the reduction of the conflict relations in traffic, as well for to prevent a great number of traffic accidents occurrences, we considered education measures that take the citizens to attitudes and behaviors of social living when they use a street common to the pedestrians and vehicles. Thus, the reach of this objective is special, once it is pledged in the search of strategies that can optimize the available resources and establish partnerships for guarantee the effectiveness of the defined strategies, driving away this mad which devastates the city
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Anotação automática de dados geográficos baseada em bancos de dados abertos e interligados. / Automatic annotation of spatial data based on open and interconnected databases.HENRIQUES, Hamon Barros. 07 May 2018 (has links)
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Previous issue date: 2015-08-31 / Recentemente, infraestruturas de dados espaciais (IDE) têm se popularizado como uma
importante solução para facilitar a interoperabilidade de dados geográficos oferecidos por
diferentes organizações. Um importante desafio que precisa ser superado por estas infraestruturas consiste em permitir que seus clientes possam localizar facilmente os dados e serviços que se encontram disponíveis. Atualmente, esta tarefa é implementada a partir de serviços de catálogo. Embora tais serviços tenham representado um importante avanço para a recuperação de dados geográficos, estes ainda possuem limitações importantes. Algumas destas limitações surgem porque os serviços de catálogo resolvem suas consultas com base nas informações contidas em seus registros de metadados, que normalmente descrevem as características do serviço como um todo. Além disso, muitos catálogos atuais resolvem consultas com restrições temáticas apenas com base em palavras-chaves, e não possuem meios formais para descrever a semântica dos recursos disponíveis. Para resolver a falta de semântica, esta dissertação apresenta uma solução para a anotação semântica automática das camadas e dos seus respectivos atributos disponibilizados em uma IDE. Com isso, motores de busca, que utilizam ontologias como insumo para a resolução de suas consultas, irão encontrar os dados geográficosqueestãorelacionadossemanticamenteaumdeterminadotema
pesquisado. Também foi descrita nesta pesquisa uma avaliação do desempenho da solução proposta sobre uma amostra de serviços Web Feature Service. / Recently, Spatial Data Infrastructure (SDI) has become popular as an important solution
for easing the interoperability if geographic data offered by different organizations. An important challenge that must be overcome by such infrastructures consists in allowing their users to easily locating the available data and services. Presently, this task is implemented by means of catalog services. Although such services represent an important advance for retrieval of geographic data, they still have serious limitations. Some of these limitations arise because the catalog service resolves their queries based on information contained in their metadata records, which normally describes the characteristics of the service as a whole. In addition, many current catalogs solve queries with thematic restrictions based only on keywords, and have no formal means for describing the semantics of available resources. To resolve the lack of semantics, this dissertation presents a solution for automatic semantic annotation of feature types and their attributes available in an IDE.With this, search engines, which use ontologies as input for solving their queries will find the geographic data that are semantically related to a particular topic searched. Also has described in this research an evaluation of the performance of the proposed solution on a sample of Web Feature Service services.
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Prise en compte des dépendances entre données thématiques utilisateur et données topographiques lors d’un changement de niveau de détail / Taking into account the dependences between user thematic data and topographic data when the level of detail is changedJaara, Kusay 10 March 2015 (has links)
Avec l'importante disponibilité de données topographiques de référence, la création des données géographiques n'est plus réservée aux professionnels de l'information géographique. De plus en plus d'utilisateurs saisissent leurs propres données, que nous appelons données thématiques, en s'appuyant sur ces données de référence qui jouent alors le rôle de données support. Les données thématiques ainsi saisies font sens en tant que telles, mais surtout de par leurs relations avec les données topographiques. La non prise en compte des relations entre données thématiques et topographiques lors de traitements modifiant les unes ou les autres peut engendrer des incohérences, notamment pour les traitements liés au changement de niveau de détail. L'objectif de la thèse est de définir une méthodologie pour préserver la cohérence entre les données thématiques et topographiques lors d'un changement de niveau de détail. Nous nous concentrons sur l'adaptation des données thématiques suite à une modification des données topographiques, processus que nous appelons migration des données thématiques. Nous proposons d'abord un modèle pour la migration de données thématiques ponctuelles sur réseau composé de : (1) un modèle pour décrire le référencement des données thématiques sur les données topographiques par des relations spatiales (2) une méthode de relocalisation basée sur ces relations. L'approche consiste à identifier les relations finales attendues en fonction des relations initiales et des changements sur les données topographiques entre les états initial et final. La relocalisation est alors effectuée grâce à une méthode multicritère de manière à respecter au mieux les relations attendues. Une mise en œuvre est présentée sur des cas d'étude jouets et sur un cas réel fourni par un service de l'Etat gestionnaire de réseau routier. Nous discutons enfin l'extension du modèle proposé pour traiter la prise en compte des relations pour d'autres applications que la migration de données thématiques / With the large availability of reference topographic data, creating geographic data is not exclusive to experts of geographic information any more. More and more users rely on reference data to create their own data, hereafter called thematic data. Reference data then play the role of support for thematic data. Thematic data make sense by themselves, but even more by their relations with topographic data. Not taking into account the relations between thematic and topographic data during processes that modify the former or the latter may cause inconsistencies, especially for processes that are related to changing the level of detail. The objective of this thesis is to define a methodology to preserve the consistency between thematic and topographic when the level of detail is modified. This thesis focuses on the adaptation of thematic data after a modification of topographic data: we call this process thematic data migration. We first propose a model for the migration of punctual thematic data hosted by a network. This model is composed of: (1) a model to describe the referencing of thematic data on topographic data using spatial relations (2) a method to re-locate thematic data based on these relations. The approach consists in identifying the expected final relations according to the initial relations and the modifications of topographic data between the initial and the final state. The thematic data are then re-located using a multi-criteria method in order to satisfy, as much as possible, the expected relations. An implementation is presented on toy problems and on a real use case provided by a French public authority in charge of road network management. The extension of the proposed model to take into account the relations for other applications than thematic data migration is also discussed
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Révision automatique des connaissances guidant l'exploration informée d'arbres d'états : application au contexte de la généralisation de données géographiques / Automatic revision of knowledge guiding informed search tree exploration : application to the context of geographic data generalisationTaillandier, Patrick 02 December 2008 (has links)
Cette thèse traite de la révision automatique des connaissances contenues dans les systèmes fonctionnant par exploration informée d'arbres d'états. Ces systèmes, de par leur performance, sont employés dans de nombreux domaines applicatifs. En particulier, des travaux ont proposés d’utiliser cette approche dans le cadre de l'automatisation de la généralisation de données géographiques. La généralisation de données géographique s'intéresse à la dérivation, à partir de données géographiques détaillées, de données moins détaillées adaptées à un besoin particulier (e.g. changement d'échelle). Son automatisation, enjeu majeur pour les agences cartographiques telles que l'Institut Géographique National (IGN), est particulièrement complexe. Les performances des systèmes basés sur l’exploration informée d'arbres d'états sont directement dépendantes de la qualité de leurs connaissances (heuristiques). Or, la définition et la mise à jour de ces dernières s'avèrent généralement fastidieuses. Dans le cadre de cette thèse, nous proposons une approche de révision hors ligne des connaissances basée sur le traçage du système et sur l'analyse de ces traces. Ces traces sont ainsi utilisées par un module de révision qui est chargé d'explorer l'espace des connaissances possibles et d'en modifier en conséquence les connaissances du système. Des outils de diagnostic en ligne de la qualité des connaissances permettent de déterminer quand déclencher le processus de révision hors ligne des connaissances. Pour chaque méthode et approche que nous présentons, une mise en oeuvre est détaillée et expérimentée dans le cadre de l'automatisation de la généralisation de données géographiques / This work deals with automatic knowledge revision in systems based on an informed tree search strategy. Because of their efficiency, these systems are used in numerous fields. In particular, some literature work uses this approach for the automation of geographic data generalisation. Geographic data generalisation is the process that derives data adapted to specific needs (e.g. map scale) from too detailed geographic data. Its automation, which is a major issue for national mapping agencies like Institut Géographique National (IGN), is particularly complex. The performances of systems based on informed tree search are directly dependant on their knowledge (heuristics) quality. Unfortunately, most of the time, knowledge definition and update are fastidious. In this work, we propose an offline knowledge revision approach based on the system logging and on the analysis of these logs. Thus, the logs are used by a revision module which is in charge of the system knowledge revision by knowledge space exploration. Tools for online knowledge quality diagnosis allow to determine when the offline knowledge process should be activated. For each method and each approach presented, an implementation is proposed in the context of geographic data generalisation
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[en] A SOFTWARE ARCHITECTURE FOR AUTOMATED CATALOGUING OF GEOGRAPHIC DATA / [pt] UMA ARQUITETURA DE SOFTWARE PARA CATALOGAÇÃO AUTOMÁTICA DE DADOS GEOGRÁFICOSLUIZ ANDRE PORTES PAES LEME 12 September 2006 (has links)
[pt] Dados geográficos estão disponíveis em quantidade e
variedade
crescentes à medida que evoluem as tecnologias de
informática. Para torná-los
úteis, é necessário que mecanismos de busca de dados
possam identificar
dados apropriados a determinado propósito. Tais
mecanismos, comumente,
utilizam catálogos de metadados que descrevem cada dado
geográfico.
Entretanto, a geração de metadados é um processo que pode
consumir muito
tempo e estar sujeito a muitos erros, caso seja feito
manualmente. Essa
dissertação apresenta uma arquitetura de software e
tecnologias correlatas
para aplicações de catalogação automática de dados
geográficos. / [en] The amount and variety of geographic data increase as
technology
evolves. To make them useful it is necessary to implement
search engines
capable of identifying appropriate data. Such engines are
usually based on
metadata catalogs which describe the geographic data.
However, the metadata
generation process is time consuming and is not fail safe
if it is carried out
manually. This dissertation presents a software
architecture, and related
technologies, for the construction of automated
cataloguing applications of
geographic data.
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