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Variable-scale topological data structures suitable for progressive data transfer: the gap-face tree and gap-edge forest / Peter J. M. Van Oosterom in Cartography and Geographic Information Science, vol 32 n° 4 (October 2005)
Titre : Variable-scale topological data structures suitable for progressive data transfer: the gap-face tree and gap-edge forest Type de document : Article/Communication Auteurs : Peter J. M. Van Oosterom, Auteur Année de publication : 2005 Article en page(s) : pp 331 - 346 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] arbre (mathématique)
[Termes IGN] architecture client-serveur
[Termes IGN] échelle variable
[Termes IGN] généralisation cartographique automatisée
[Termes IGN] modèle topologique de données
[Termes IGN] transmission de donnéesRésumé : (Auteur) This paper presents the first data structure for a variable scale representation of an area partitioning without redundancy of geometry. At the highest level of detail, the areas are represented using a topological structure based on faces and edges; there is no redundancy of geometry in this structure as the shared boundaries (edges) between neighbour areas are stored only once. Each edge is represented by a Binary Line Generalization (BLG)-tree, which enables selection of the proper representation for a given scale. Further, there is also no geometry redundancy between the different levels of detail. An edge at a higher importance level (less detail) does not contain copies of the lower-level edges or coordinates (more detail), but it is represented by efficiently combining their corresponding BLG trees. Which edges have to be combined follows from the generalization computation, and this is stored in a data structure. This data structure turns out to be a set of trees, which will be called the (Generalized Area Partitioning) GAP-edge forest. With regard to faces, the generalization result can be captured in a single tree structure for the parent-child relationships - the GAP face-tree. At the client side there are no geometric computations necessary to compute the polygon representations of the faces, merely following the topological references is sufficient. Finally, the presented data structure is also suitable for progressive transfer of vector maps, assuming that the client maintains a local copy of the GAP-face tree and the GAP-edge forest. Numéro de notice : A2005-536 Affiliation des auteurs : non IGN Thématique : FORET/GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1559/152304005775194782 En ligne : https://doi.org/10.1559/152304005775194782 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27672
in Cartography and Geographic Information Science > vol 32 n° 4 (October 2005) . - pp 331 - 346[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 032-05041 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : Building displacement over a ductile truss Type de document : Article/Communication Auteurs : M. Bader, Auteur ; Mathieu Barrault Année de publication : 2005 Article en page(s) : pp 915 - 936 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] algorithme STA
[Termes IGN] contrainte d'intégrité
[Termes IGN] déplacement d'objet géographique
[Termes IGN] généralisation cartographique automatisée
[Termes IGN] graphe
[Termes IGN] intégrité des données
[Termes IGN] itération
[Termes IGN] objet cartographique
[Termes IGN] optimisation (mathématiques)
[Vedettes matières IGN] GénéralisationRésumé : (Auteur) Displacement, an operation of cartographic generalization, resolves congestion and overlap of map features that is caused by enlargement of map symbols to ensure readability at reduced scales. Algorithms for displacement must honour spatial context, avoid creating secondary spatial conflicts, and retain spatial patterns and relations such as alignments and relative distances that characterize the original map features. We present an algorithm for displacement of buildings based on optimization. While existing approaches directly displace the individual buildings, our algorithm first forms a truss of elastic beams to capture important spatial patterns and preserve them during displacement. The algorithm proceeds in two phases. The first phase analyses spatial relationships to construct a truss as a weighted graph. The truss is initially based on the minimum spanning tree connecting the building centroids, with beam stiffness determined by spatial relationships. The second phase iteratively deforms the truss to minimize energy until a user-defined distance is achieved. At each iteration, it computes forces on the truss, calculates truss deformations, and adjusts all build positions simultaneously. A prototype has been implemented to demonstrate the feasibility of the approach. The results are cartographically pleasing ; in particular, spatial relationships between buildings are preserved. Numéro de notice : A2005-407 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810500161237 En ligne : https://doi.org/10.1080/13658810500161237 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27543
in International journal of geographical information science IJGIS > vol 19 n° 8 - 9 (september 2005) . - pp 915 - 936[article]Exemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-05081 RAB Revue Centre de documentation En réserve L003 Disponible 079-05082 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : Les SIG à l'assaut de la complexité Type de document : Article/Communication Auteurs : Françoise de Blomac, Auteur Année de publication : 2005 Article en page(s) : pp 9 - 11 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique
[Termes IGN] accessibilité
[Termes IGN] aménagement urbain
[Termes IGN] analyse spatiale
[Termes IGN] complexité
[Termes IGN] données localisées 3D
[Termes IGN] flux
[Termes IGN] formalisation
[Termes IGN] grande échelle
[Termes IGN] graphe planaire
[Termes IGN] mobilité humaine
[Termes IGN] représentation mentale spatiale
[Termes IGN] représentation spatiale
[Termes IGN] système d'information géographique
[Termes IGN] système multi-agentsRésumé : (Auteur) Le colloque Sageo, organisé fin juin à Avignon a rassemblé plus de 100 chercheurs en géomatique et en analyse spatiale. Thèses et programmes de recherche menés à plusieurs laboratoires s'attaquent à tous les aspects de l'information géographique : télédétection, réseaux de transports, représentation spatiale, gestion des risques... De plus en plus de travaux associent informaticiens et géographes. Ensemble, ils poussent les SIG à leur extrême limite et remettent en cause leur structuration habituelle sous forme de couches, afin de mieux rendre compte de la complexité du monde. Ils ouvrent ainsi des pistes intéressantes, même si elles sont parfois loin d'être abouties. Numéro de notice : A2005-350 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27486
in SIG la lettre > n° 69 (septembre 2005) . - pp 9 - 11[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 286-05071 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : Visualizing demographic trajectories with self-organizing maps Type de document : Article/Communication Auteurs : A. Skupin, Auteur ; R. Hagelman, Auteur Année de publication : 2005 Article en page(s) : pp 159 - 179 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse diachronique
[Termes IGN] analyse spatiale
[Termes IGN] carte de Kohonen
[Termes IGN] données démographiques
[Termes IGN] données multidimensionnelles
[Termes IGN] données socio-économiques
[Termes IGN] graphe
[Termes IGN] noeud
[Termes IGN] représentation spatiale
[Termes IGN] réseau neuronal artificiel
[Termes IGN] système d'information géographique
[Termes IGN] trajectoire (véhicule non spatial)
[Termes IGN] visualisation de données
[Vedettes matières IGN] GéovisualisationRésumé : (Auteur) In recent years, the proliferation of multi-temporal census data products and the increased capabilities of geospatial analysis and visualization techniques have encouraged longitudinal analyses of socioeconomic census data. Traditional cartographic methods for illustrating socioeconomic change tend to rely either on comparison of multiple temporal snapshots or on explicit representation of the magnitude of change occurring between different time periods. This paper proposes to add another perspective to the visualization of temporal change, by linking multi-temporal observations to a geometric configuration that is not based on geographic space, but on a spatialized representation of n-dimensional attribute space. The presented methodology aims at providing a cognitively plausible representation of changes occurring inside census areas by representing their attribute space trajectories as line features traversing a two-dimensional display space. First, the self-organizing map (SOM) method is used to transform n-dimensional data such that the resulting two-dimensional configuration can be represented with standard GIS data structures. Then, individual census observations are mapped onto the neural network and linked as temporal vertices to represent attribute space trajectories as directed graphs. This method is demonstrated for a data set containing 254 counties and 32 demographic variables. Various transformations and visual results are presented and discussed in the paper, from the visualization of individual component planes and trajectory clusters to the mapping of different attributes onto temporal trajectories. Numéro de notice : A2005-225 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-005-6670-2 En ligne : https://doi.org/10.1007/s10707-005-6670-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27362
in Geoinformatica > vol 9 n° 2 (June - August 2005) . - pp 159 - 179[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 057-05021 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : A layered stereo matching algorithm using segmentation and global visibility constraints Type de document : Article/Communication Auteurs : M. Bleyer, Auteur ; M. Gelautz, Auteur Année de publication : 2005 Article en page(s) : pp 128 - 150 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] algorithme de décalage moyen
[Termes IGN] algorithme glouton
[Termes IGN] appariement de données localisées
[Termes IGN] compensation par moindres carrés
[Termes IGN] couche thématique
[Termes IGN] détection de partie cachée
[Termes IGN] extraction de couche
[Termes IGN] fenêtre (informatique)
[Termes IGN] graphe planaire
[Termes IGN] programmation par contraintes
[Termes IGN] segmentation d'image
[Termes IGN] visibilité
[Termes IGN] visualisation 3D
[Termes IGN] zone tamponRésumé : (Auteur) This work describes a stereo algorithm that takes advantage of image segmentation, assuming that disparity varies smoothly inside a segment of homogeneous colour and depth discontinuities coincide with segment borders. Image segmentation allows our method to generate correct disparity estimates in large untextured regions and precisely localize depth boundaries. The disparity inside a segment is represented by a planar equation. To derive the plane model, an initial disparity map is generated. We use a window-based approach that exploits the results of segmentation. The size of the match window is chosen adaptively. A segment's planar model is then derived by robust least squared error fitting using the initial disparity map. In a layer extraction step, disparity segments that are found to be similar according to a plane dissimilarity measurement are combined to form a single robust layer. We apply a modified mean-shift algorithm to extract clusters of similar disparity segments. Segments of the same cluster build a layer, the plane parameters of which are computed from its spatial extent using the initial disparity map. We then optimize the assignment of segments to layers using a global cost function. The quality of the disparity map is measured by warping the reference image to the second view and comparing it with the real image. Z-buffering enforces visibility and allows the explicit detection of occlusions. The cost function measures the colour dissimilarity between the warped and real views, and penalizes occlusions and neighbouring segments that are assigned to different layers. Since the problem of finding the assignment of segments to layers that minimizes this cost function is NP-complete, an efficient greedy algorithm is applied to find a local minimum. Layer extraction and assignment are alternately applied. Qualitative and quantitative results obtained for benchmark image pairs show that the proposed algorithm outperforms most state-of-the-art matching algorithms currently listed on the Middlebury stereo evaluation website. The technique achieves particularly good results in areas with depth discontinuities and related occlusions, where missing stereo information is substituted from surrounding regions. Furthermore, we apply the algorithm to a self-recorded image set and show 3D visualizations of the derived results. Numéro de notice : A2005-229 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2005.02.008 En ligne : https://doi.org/10.1016/j.isprsjprs.2005.02.008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27366
in ISPRS Journal of photogrammetry and remote sensing > vol 59 n° 3 (May 2005) . - pp 128 - 150[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 081-05011 SL Revue Centre de documentation Revues en salle Disponible PermalinkPermalinkPermalinkPermalinkPermalinkModélisation des réseaux de transport intermodal : vers une plus grande précision de l'accessibilité, Volume 1. Mémoire / Z. Chen (2005)
PermalinkPermalinkPlate-forme AFIA, Nice, 30 mai - 3 juin 2005, 2. Journée thématique Raisonner le web sémantique avec des graphes / Michel Leclère (2005)
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