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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)
[article]
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 DelaunayRésumé : (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
in International journal of geographical information science IJGIS > vol 22 n° 4-5 (april 2008) . - pp 449 - 462[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-08031 RAB Revue Centre de documentation En réserve L003 Disponible 079-08032 RAB Revue Centre de documentation En réserve L003 Disponible Approximating the visible region of a point on a terrain / B. Ben-Moshe in Geoinformatica, vol 12 n° 1 (March - May 2008)
[article]
Titre : Approximating the visible region of a point on a terrain Type de document : Article/Communication Auteurs : B. Ben-Moshe, Auteur ; P. Carmi, Auteur ; M.J. Katz, Auteur Année de publication : 2008 Article en page(s) : pp 21 - 36 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] approximation
[Termes IGN] interpolation
[Termes IGN] Triangulated Irregular Network
[Termes IGN] visibilitéRésumé : (Auteur) Given a terrain and a point p on or above it, we wish to compute the region Rp that is visible from p. We present a generic radar-like algorithm for computing an approximation of Rp. The algorithm interpolates the visible region between two consecutive rays (emanating from p) whenever the rays are close enough; that is, whenever the difference between the sets of visible segments along the cross sections in the directions specified by the rays is below some threshold. Thus the density of the sampling by rays is sensitive to the shape of the visible region. We suggest a specific way to measure the resemblance (difference) and to interpolate the visible region between two consecutive rays. We also present an alternative algorithm, which uses circles of increasing radii centered at p instead of rays emanating from p. Both algorithms compute a representation of the (approximated) visible region that is especially suitable for is-visible-from-p queries, i.e., given a query point q on the terrain determine whether q is visible from p. Finally, we report on the experiments that we performed with these algorithms and with their corresponding fixed versions, using a natural error measure. Our main conclusion is that the radar-like algorithm is significantly better than the others. Copyright Springer Numéro de notice : A2008-068 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-006-0017-5 En ligne : https://doi.org/10.1007/s10707-006-0017-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29063
in Geoinformatica > vol 12 n° 1 (March - May 2008) . - pp 21 - 36[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 057-08011 RAB Revue Centre de documentation En réserve L003 Disponible A multi-parameter approach to automated building grouping and generalization / Hongxiang Yan in Geoinformatica, vol 12 n° 1 (March - May 2008)
[article]
Titre : A multi-parameter approach to automated building grouping and generalization Type de document : Article/Communication Auteurs : Hongxiang Yan, Auteur ; Robert Weibel, Auteur ; B. Yang, Auteur Année de publication : 2008 Article en page(s) : pp 73 - 89 Langues : Anglais (eng) Descripteur : [Termes IGN] détection du bâti
[Termes IGN] diagramme de Voronoï
[Termes IGN] généralisation cartographique automatisée
[Termes IGN] généralisation du bâti
[Termes IGN] triangulation de Delaunay
[Vedettes matières IGN] GénéralisationRésumé : (Auteur) This paper presents an approach to automated building grouping and generalization. Three principles of Gestalt theories, i.e. proximity, similarity, and common directions, are employed as guidelines, and six parameters, i.e. minimum distance, area of visible scope, area ratio, edge number ratio, smallest minimum bounding rectangle (SMBR), directional Voronoi diagram (DVD), are selected to describe spatial patterns, distributions and relations of buildings. Based on these principles and parameters, an approach to building grouping and generalization is developed. First, buildings are triangulated based on Delaunay triangulation rules, by which topological adjacency relations between buildings are obtained and the six parameters are calculated and recorded. Every two topologically adjacent buildings form a potential group. Three criteria from previous experience and Gestalt principles are employed to tell whether a 2-building group is ‘strong,’ ‘average’ or ‘weak.’ The ‘weak’ groups are deleted from the group array. Secondly, the retained groups with common buildings are organized to form intermediate groups according to their relations. After this step, the intermediate groups with common buildings are aggregated or separated and the final groups are formed. Finally, appropriate operators/algorithms are selected for each group and the generalized buildings are achieved. This approach is fully automatic. As our experiments show, it can be used primarily in the generalization of buildings arranged in blocks. Copyright Springer Numéro de notice : A2008-070 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-007-0020-5 En ligne : https://doi.org/10.1007/s10707-007-0020-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29065
in Geoinformatica > vol 12 n° 1 (March - May 2008) . - pp 73 - 89[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 057-08011 RAB Revue Centre de documentation En réserve L003 Disponible Identifying factors of geographic event conceptualisation / Alexander Klippel in International journal of geographical information science IJGIS, vol 22 n° 1-2 (february 2008)
[article]
Titre : Identifying factors of geographic event conceptualisation Type de document : Article/Communication Auteurs : Alexander Klippel, Auteur ; Michael F. Worboys, Auteur ; Matt Duckham, Auteur Année de publication : 2008 Article en page(s) : pp 183 - 204 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] analyse spatio-temporelle
[Termes IGN] graphe
[Termes IGN] modélisation spatio-temporelle
[Termes IGN] ontologie
[Termes IGN] relation topologique
[Termes IGN] variable régionalisée
[Termes IGN] voisinage (relation topologique)Résumé : (Auteur) The present paper examines whether the formal topological characterisation of spatial relations between moving geographic regions provides an adequate basis for the human conceptualisation of motion events for those regions. The paper focuses on gradual changes in topological relationships caused by continuous transformations of the regions (specifically, translations). Using a series of experiments, the conceptualisation and perception of conceptual neighborhoods is investigated. In particular, the role of conceptual neighborhoods in characterising motion events is scrutinised. The experiments employ a grouping paradigm and a custom-made tool for presenting animated icons. The analysis examines whether paths through a conceptual neighborhood graph sufficiently characterise the conceptualisation of the movement of two regions. The results of the experiments show that changes in topological relations—as detailed by paths through a conceptual neighborhood graph—are not sufficient to characterise the cognitive conceptualisation of moving regions. The similarity ratings show clear effects of perceptually and conceptually induced groupings such as identity (which region is moving), reference (whether a larger or a smaller region is moving), and dynamics (whether both regions are moving at the same time). Copyright Taylor & Francis Numéro de notice : A2008-107 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810701405607 En ligne : https://doi.org/10.1080/13658810701405607 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29102
in International journal of geographical information science IJGIS > vol 22 n° 1-2 (february 2008) . - pp 183 - 204[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-08011 RAB Revue Centre de documentation En réserve L003 Disponible 079-08012 RAB Revue Centre de documentation En réserve L003 Disponible Web service approaches for providing enriched data structures to generalisation operators / Moritz Neun in International journal of geographical information science IJGIS, vol 22 n° 1-2 (february 2008)
[article]
Titre : Web service approaches for providing enriched data structures to generalisation operators Type de document : Article/Communication Auteurs : Moritz Neun, Auteur ; Robert Weibel, Auteur ; Dirk Burghardt, Auteur Année de publication : 2008 Article en page(s) : pp 133 - 165 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] approche hiérarchique
[Termes IGN] base de connaissances
[Termes IGN] généralisation cartographique automatisée
[Termes IGN] grammaire de graphes
[Termes IGN] graphe
[Termes IGN] opérateur de généralisation
[Termes IGN] service web
[Termes IGN] structure de données localisées
[Vedettes matières IGN] GénéralisationRésumé : (Auteur) Web service technologies can be used to establish an interoperable framework between different generalisation systems. In a previous article three categories of generalisation web services were identified, including support services, operator services and processing services. This paper focuses on the category of support services. In a service-based generalisation system, the purpose of support services is to assist the generalisation process by providing auxiliary measures, procedures and data structures that allow the representation of structural cartographic knowledge. The structural knowledge of the spatial and semantic context and the modelling of structural and spatial relationships is critical for the understanding of the role of cartographic features and thus for automated generalisation. Support services should extract and model this knowledge from the raw data and make it available to other generalisation operators. On the one hand the structural knowledge can be expressed by enriching map features with additional geometries or attributes. On the other hand, there exist various hierarchical and non-hierarchical relationships between map features, many of which can be represented by graph data structures. After a brief introduction to the interoperable web service framework, this paper proposes a taxonomy of generalisation support services and discusses its elements. It is then shown how the complex output of such services can be represented for use with web services and stored in a reusable fashion. Finally, the utilisation of support services is illustrated on four implementation examples of support services that also highlight the interactions with the generalisation operators that use these auxiliary services. Copyright Taylor & Francis Numéro de notice : A2008-105 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810701348997 En ligne : https://www.tandfonline.com/doi/full/10.1080/13658810701348997 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29100
in International journal of geographical information science IJGIS > vol 22 n° 1-2 (february 2008) . - pp 133 - 165[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-08011 RAB Revue Centre de documentation En réserve L003 Disponible 079-08012 RAB Revue Centre de documentation En réserve L003 Disponible La géomatique au service de la caractérisation automatique des réseaux hydrographiques / Adrien Paget in Physio-Géo, vol 2 (janvier 2008)PermalinkPermalinkPermalinkPermalinkPermalinkDiagnosis in systems based on an informed tree search strategy: application to cartographic generalisation / Patrick Taillandier (2008)PermalinkEtude et développement d'un outil de mise en correspondance / Marie Feisthauer (2008)PermalinkPermalinkKnowledge revision in systems based on an informed tree search strategy: application to cartographic generalisation / Patrick Taillandier (2008)PermalinkRévision automatique des connaissances guidant l'exploration informée d'arbres d'états / Patrick Taillandier (2008)Permalink