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An object-oriented data model for complex objects in three-dimensional geographical information systems / Wei Shi in International journal of geographical information science IJGIS, vol 17 n° 5 (july - August 2003)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 17 n° 5 (july - August 2003) . - pp 411 - 430 Titre : An object-oriented data model for complex objects in three-dimensional geographical information systems Type de document : Article/Communication Auteurs : Wei Shi, Auteur ; B. Yang, Auteur ; Qi Li, Auteur Année de publication : 2003 Article en page(s) : pp 411 - 430 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] analyse spatiale [Termes IGN] modèle 3D de l'espace urbain [Termes IGN] modèle conceptuel de données [Termes IGN] modèle orienté objet [Termes IGN] modélisation 3D [Termes IGN] objet géographique 3D [Termes IGN] objet géographique complexe [Termes IGN] primitive géométrique [Termes IGN] primitive volumique [Termes IGN] requête spatiale [Termes IGN] SIG 3D [Termes IGN] ville [Termes IGN] visualisation 3D Résumé : (Auteur) Developing a three-dimensional (3D) data model for Geographic Information Systems (GIS) is an essential and complex issue. 3D modelling in GIS is becoming ever more important for the development of cyber cities and digital earth, which have recently become feasible. A competent 3D model forms an efficient foundation for 3D visualization, query and spatial analysis. As a development of the existing 3D models, this study proposes particular improvements in handling complex 3D objects. We present an object-oriented data model for handling complex 3D objects in GIS. First, the conceptual data model is developed based on the principle of object-oriented (00) data modelling. This model is designed based on the following three basic geometric elements: node, segment and triangle. Accordingly, the abstract geometric objects are defined: including points, lines, surfaces and volumes. Second, the corresponding 3D logical model is designed based on the defined abstract objects and the relationships between them. Third, a formal representation of the 3D spatial objects is described in detail. Fourth, a prototype 3D GIS is developed based on the proposed 3D data model. Finally, we describe the results of an experimental study to reconstruct 3D objects using this 3D GIS and a comparison with the performance of other 3D data models. The proposed model is able to handle complex objects, such as complex buildings and TV towers, which is an essential functionality for building large-scale cyber cities, such as for Hong Kong. The proposed data model proves to be very efficient, particularly in visualization and rendering. The experimental results show which the data volume of the proposed model is compacted and the visualization speed for 3D objects is improved, compared with the existing models. Numéro de notice : A2003-142 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1080/1365881031000086974 En ligne : https://doi.org/10.1080/1365881031000086974 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22438 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-03051	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-03052	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Comparing two sets of polygons / M. Gombosi in International journal of geographical information science IJGIS, vol 17 n° 5 (july - August 2003)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 17 n° 5 (july - August 2003) . - pp 431 - 443 Titre : Comparing two sets of polygons Type de document : Article/Communication Auteurs : M. Gombosi, Auteur ; B. Zalik, Auteur ; S. Krivograd, Auteur Année de publication : 2003 Article en page(s) : pp 431 - 443 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique [Termes IGN] analyse comparative [Termes IGN] cadastre [Termes IGN] polygone [Termes IGN] reconnaissance de formes Résumé : (Auteur) In this article, a new algorithm for determining differences between two sets of polygons is considered. It has been proven that it is enough to test only the polygon edges to perform the comparison. The algorithm works in two steps. First, the polygon edges are initialised into a data structure and equal edges are eliminated by a simple criterion. In the second part, the algorithm analyses the remaining edges and prepares a report about the detected differences. To speed-up the geometric search, the algorithm uses a combination of a uniform space subdivision and binary searching trees. It has been shown that the algorithm is numerically stable, and works well with a limited set of non-simple polygons from a land cadastre. The algorithm's time complexity is O(n log n), and space complexity O(n), where n is the common number of edges in both sets of polygons. This is been confirmed by experiments using data sets from the land cadastre. Numéro de notice : A2003-143 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/1365881031000072627 En ligne : https://doi.org/10.1080/1365881031000072627 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22439 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-03051	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-03052	RAB	Revue	Centre de documentation	En réserve L003	Disponible

A GIS-based spatial pattern analysis model for eco-region mapping and characterization / Y. Zhou in International journal of geographical information science IJGIS, vol 17 n° 5 (july - August 2003)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 17 n° 5 (july - August 2003) . - pp 445 - 462 Titre : A GIS-based spatial pattern analysis model for eco-region mapping and characterization Type de document : Article/Communication Auteurs : Y. Zhou, Auteur ; S. Narumalani, Auteur ; W.J. Waltman, Auteur ; et al., Auteur Année de publication : 2003 Article en page(s) : pp 445 - 462 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] analyse spatiale [Termes IGN] carte thématique [Termes IGN] délimitation [Termes IGN] écosystème [Termes IGN] Nebraska (Etats-Unis) [Termes IGN] polygone [Termes IGN] reconnaissance de formes Résumé : (Auteur) Growing concerns about global climate change, biodiversity maintenance, natural resources conservation, and long-term ecosystem sustainability have been responsible for the transformation of traditional single resource management approaches into integrated ecosystem management models. Eco-regions are large ecosystems of regional extent that contain smaller ecosystems of similar response potential and resource production capabilities. They can be used as a geographical framework for organizing and reporting resource information, setting bioecological recovery criteria, extrapolating site-level management, and monitoring global change. The objective of this research is to develop a quantitative, multivariate regionalization model that is capable of delineating eco-regions at multiple levels from remotely sensed information and other environmental and natural resources spatial data. The Spatial Pattern Analysis Model developed in this study uses a region-growing algorithm to generate spatially contiguous regions from primitive polygonal land units. The algorithm merges the most similar pair of neighbouring units at each iteration, based on satisfying certain similarity criteria until all units are grouped into one. This model was utilized to develop an eco-region map of Nebraska with three hierarchical levels. In the mapping process, the STATSGO data set was used to build the primitive map units. Environmental parameters included in the model were multi-temporal AVHRR data, soil rooting depth, organic matter content, available water capacity, and long-term annual averages of water balance and growing degree day totals. Numéro de notice : A2003-144 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1080/1365881031000086983 En ligne : https://doi.org/10.1080/1365881031000086983 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22440 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-03051	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-03052	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Modelling urban growth and landscape changes in the Atlanta metropolitan area / X. Yang in International journal of geographical information science IJGIS, vol 17 n° 5 (july - August 2003)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 17 n° 5 (july - August 2003) . - pp 463 - 488 Titre : Modelling urban growth and landscape changes in the Atlanta metropolitan area Type de document : Article/Communication Auteurs : X. Yang, Auteur ; C.P. Lo, Auteur Année de publication : 2003 Article en page(s) : pp 463 - 488 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Urbanisme [Termes IGN] Atlanta (Géorgie) [Termes IGN] croissance urbaine [Termes IGN] métropole [Termes IGN] modèle de simulation Résumé : (Auteur) We use an urban growth model, closely coupled with a land transition model, to simulate future urban growth in the Atlanta metropolitan area, one of the fastest growing metropolises in the United States during the past three decades. We calibrate the model with historical data that are extracted from a time series of satellite images. We design three specific scenarios to simulate the spatial consequences of urban growth under different environmental conditions. The first scenario is to simulate the continued growth trend by maintaining unchanged the current conditions. The second scenario is to project the growth trend by taking into consideration road development and environmental protection. The third scenario is to simulate the development trend by slowing down growth and changing growth pattern. The first two scenarios demonstrate that unchecked urban growth would result in the displacement of almost the entire natural vegetation and all of the open space in the metro area. In contrast, the result from the third scenario shows that much more greenness and open space, including buffer zones of large streams and lakes, could be preserved. Accordingly, the last scenario should be the most desirable for the future urban growth of Atlanta. We also examine the model's effectiveness as applied to the Atlanta area and suggest future research directions for more accurate simulations. Numéro de notice : A2003-145 Affiliation des auteurs : non IGN Thématique : URBANISME Nature : Article DOI : 10.1080/1365881031000086965 En ligne : https://doi.org/10.1080/1365881031000086965 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22441 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-03051	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-03052	RAB	Revue	Centre de documentation	En réserve L003	Disponible