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Sweep-line algorithm for constrained Delaunay triangulation / V. Domiter in International journal of geographical information science IJGIS, vol 22 n° 4-5 (april 2008)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 22 n° 4-5 (april 2008) . - pp 449 - 462 Titre : Sweep-line algorithm for constrained Delaunay triangulation Type de document : Article/Communication Auteurs : V. Domiter, Auteur ; B. Zalik, Auteur Année de publication : 2008 Article en page(s) : pp 449 - 462 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique [Termes IGN] contrainte géométrique [Termes IGN] isoligne [Termes IGN] triangulation de Delaunay Résumé : (Auteur) This paper introduces a new algorithm for constrained Delaunay triangulation, which is built upon sets of points and constraining edges. It has various applications in geographical information system (GIS), for example, iso-lines triangulation or the triangulation of polygons in land cadastre. The presented algorithm uses a sweep-line paradigm combined with Lawson's legalisation. An advancing front moves by following the sweep-line. It separates the triangulated and non-triangulated regions of interest. Our algorithm simultaneously triangulates points and constraining edges and thus avoids consuming location of those triangles containing constraining edges, as used by other approaches. The implementation of the algorithm is also considerably simplified by introducing two additional artificial points. Experiments show that the presented algorithm is among the fastest constrained Delaunay triangulation algorithms available at the moment. Copyright Taylor & Francis Numéro de notice : A2008-149 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/13658810701492241 En ligne : https://doi.org/10.1080/13658810701492241 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29144 [article]

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079-08032	RAB	Revue	Centre de documentation	En réserve L003	Disponible

K-guarding of polyhedral terrain / B. Kaucic in International journal of geographical information science IJGIS, vol 18 n° 7 (november 2004)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 18 n° 7 (november 2004) . - pp 709 - 718 Titre : K-guarding of polyhedral terrain Type de document : Article/Communication Auteurs : B. Kaucic, Auteur ; B. Zalik, Auteur Année de publication : 2004 Article en page(s) : pp 709 - 718 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG [Termes IGN] méthode heuristique [Termes IGN] polyèdre [Termes IGN] visibilité Résumé : (Auteur) Site visibility analysis is an important research topic with many applications in Geographical Information Systems. This paper introduces a new paradigm in terrain guarding, called k-guarding. K-guarding is a generalization of the classic guarding problem where, instead of only one guard, each surface patch is guarded by at least k guards. Afterwards, two optimization problems based on k-guarding are defined : an optimum k-guarding, and a constrained k-guarding. There are three heuristic approaches - k-greedy add, k-stingy drop, and k-reverse greedy -that are proposed as a solution to the above-mentioned optimization problems. The first two are known approaches adapted to k-guarding, while k-reverse greedy is a new, original heuristic. The heuristics are compared using actual topographic surfaces. It is shown that our approach (k-reverse greedy) gives on average the best near optimum solutions. The most surprising finding of the experiments is that the combination of heuristics introduced here yields even better results. Numéro de notice : A2004-398 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810410001705299 En ligne : https://doi.org/10.1080/13658810410001705299 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26925 [article]

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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]

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079-03051	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-03052	RAB	Revue	Centre de documentation	En réserve L003	Disponible