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[article]
Titre : On visibility and empty-region graphs Type de document : Article/Communication Auteurs : Sagi Katz, Auteur ; Ayellet Tal, Auteur Année de publication : 2017 Article en page(s) : pp 45 - 52 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] graphe
[Termes IGN] semis de points
[Termes IGN] traitement de données localisées
[Termes IGN] triangulation de Delaunay
[Termes IGN] visibilitéRésumé : (auteur) Empty-region graphs are well-studied in Computer Graphics, Geometric Modeling, Computational Geometry, as well as in Robotics and Computer Vision. The vertices of these graphs are points in space, and two vertices are connected by an arc if there exists an empty region of a certain shape and size between them. In most of the graphs discussed in the literature, the empty region is assumed to be a circle or the union/intersection of circles. In this paper we propose a new type of empty-region graphs—the γ-visibility graph. This graph can accommodate a variety of shapes of empty regions and may be defined in any dimension. Interestingly, we will show that commonly-used shapes are a special case of our graph. In this sense, our graph generalizes some empty-region graphs. Though this paper is mostly theoretical, it may have practical implication—the numerous applications that make use of empty-region graphs would be able to select the best shape that suits the problem at hand. Numéro de notice : A2017-564 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.cag.2017.05.007 En ligne : https://doi.org/10.1016/j.cag.2017.05.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86646
in Computers and graphics > vol 66 (August 2017) . - pp 45 - 52[article]Constrained Palette-Space Exploration / Nicolas Mellado in ACM Transactions on Graphics, TOG, Vol 36 n° 4 (July 2017)
[article]
Titre : Constrained Palette-Space Exploration Type de document : Article/Communication Auteurs : Nicolas Mellado, Auteur ; David Vanderhaeghe, Auteur ; Charlotte Hoarau , Auteur ; Sidonie Christophe , Auteur ; Mathieu Brédif , Auteur ; Loïc Barthe, Auteur Année de publication : 2017 Projets : 1-Pas de projet / Conférence : SIGGRAPH 2017, ACM conference 30/07/2017 03/08/2017 Los Angeles Californie - Etats-Unis Article en page(s) : 14 p. Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] cartologie
[Termes IGN] chromatopsie
[Termes IGN] graphe
[Termes IGN] interpolation
[Termes IGN] palette de couleurs
[Termes IGN] personne malvoyante
[Termes IGN] programmation par contraintes
[Vedettes matières IGN] GéovisualisationRésumé : (Auteur) Color palettes are widely used by artists to define colors of artworks and explore color designs. In general, artists select the colors of a palette by following a set of rules, e.g. contrast or relative luminance. Existing interactive palette exploration tools explore palette spaces following limited constraints defined as geometric configurations in color space e.g. harmony rules on the color wheel. Palette search algorithms sample palettes from color relations learned from an input dataset, however they cannot provide interactive user edits and palette refinement. We introduce in this work a new versatile formulation enabling the creation of constraint-based interactive palette exploration systems. Our technical contribution is a graph-based palette representation, from which we define palette exploration as a minimization problem that can be solved efficiently and provide real-time feedback. Based on our formulation, we introduce two interactive palette exploration strategies: constrained palette exploration, and for the first time, constrained palette interpolation. We demonstrate the performances of our approach on various application cases and evaluate how it helps users finding trade-offs between concurrent constraints. Numéro de notice : A2017-404 Affiliation des auteurs : LASTIG COGIT+Ext (2012-2019) Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1145/3072959.3073650 Date de publication en ligne : 20/07/2017 En ligne : https://doi.org/10.1145/3072959.3073650 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86220
in ACM Transactions on Graphics, TOG > Vol 36 n° 4 (July 2017) . - 14 p.[article]Documents numériques
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A2017-404_Constrained Palette-Space ExplorationAdobe Acrobat PDF Graph mapping: Multi-scale community visualization of massive graph data / David Jonker in Information visualization, vol 16 n° 3 (July 2017)
[article]
Titre : Graph mapping: Multi-scale community visualization of massive graph data Type de document : Article/Communication Auteurs : David Jonker, Auteur ; Scott Langevin, Auteur ; David Giesbrecht, Auteur ; et al., Auteur Année de publication : 2017 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] graphe
[Termes IGN] regroupement de données
[Termes IGN] traitement réparti
[Termes IGN] visualisation multiéchelle
[Vedettes matières IGN] GéovisualisationRésumé : (auteur) Graph visualizations increase the perception of entity relationships in a network. However, as graph size and density increases, readability rapidly diminishes. In this article, we present an end-to-end, tile-based visual analytic approach called graph mapping that utilizes cluster computing to turn large-scale graph (node–link) data into interactive visualizations in modern web browsers. Our approach is designed for end-user analysis of community structure and relationships at macro- and micro scales. We also present the results of several experiments using alternate methods for qualitatively improving comprehensibility of hierarchical community detection visualizations by proposing constraints to state-of-the-art modularity maximization algorithms. Numéro de notice : A2017-758 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1177/1473871616661195 En ligne : https://doi.org/10.1177/1473871616661195 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89117
in Information visualization > vol 16 n° 3 (July 2017)[article]Popularity-aware collective keyword queries in road networks / Sen Zhao in Geoinformatica, vol 21 n° 3 (July - September 2017)
[article]
Titre : Popularity-aware collective keyword queries in road networks Type de document : Article/Communication Auteurs : Sen Zhao, Auteur ; Xiang Cheng, Auteur ; Sen Su, Auteur ; Kai Shuang, Auteur Année de publication : 2017 Article en page(s) : pp 485 - 518 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web
[Termes IGN] graphe
[Termes IGN] langage de requête
[Termes IGN] langage naturel (informatique)
[Termes IGN] point d'intérêt
[Termes IGN] positionnement automatique
[Termes IGN] requête (informatique)
[Termes IGN] réseau routierRésumé : (Auteur) This paper addresses a popularity-aware collective keyword (PAC-K) query in road networks. Given a road network with POIs (Points of Interest), which is modeled as a road network graph, where each node locating in a two-dimensional space represents a road intersection or a POI, and each edge with weight represents a road segment, the PACK query aims to find a group of popular POIs (i.e., a popular region) that cover the query’s keywords and satisfy the distance requirements from each node to the query node and between each pair of nodes, such that the sum of rating scores over these nodes for the query keywords is maximized. We show the problem of answering the PACK query is NP-Hard. To solve this problem, we present exact and heuristic solutions on small and large road networks, respectively. In particular, to improve query performance, we propose a rating score scaling technique to reduce the search space and a redundant computation reducing technique to reduce the excessive redundant computations in query processing. Extensive performance studies using two real datasets confirm the efficiency, accuracy, and scalability of the proposed solutions. Numéro de notice : A2017-378 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-017-0299-9 En ligne : https://doi.org/10.1007/s10707-017-0299-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85810
in Geoinformatica > vol 21 n° 3 (July - September 2017) . - pp 485 - 518[article]Effectiveness of Natura 2000 network in Romanian Alpine Biogeographical Region: an assessment based on forest landscape connectivity / Mihaita Iulian Niculae in Annals of forest research, vol 60 n° 1 (January - June 2017)
[article]
Titre : Effectiveness of Natura 2000 network in Romanian Alpine Biogeographical Region: an assessment based on forest landscape connectivity Type de document : Article/Communication Auteurs : Mihaita Iulian Niculae, Auteur ; Sorin Avram, Auteur ; Gabriel Ovidiu Vanau, Auteur ; Maria Patroescu, Auteur Année de publication : 2017 Article en page(s) : pp 19 - 32 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] connexité (topologie)
[Termes IGN] corridor biologique
[Termes IGN] forêt tempérée
[Termes IGN] graphe
[Termes IGN] politique de conservation (biodiversité)
[Termes IGN] Roumanie
[Termes IGN] site Natura 2000
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) Maintaining and increasing landscape connectivity, especially of forest landscapes, are some of the main concerns regarding biodiversity conservation. The connectivity of protected areas for different species represents an indicator for evaluating the effectiveness of the Natura 2000 network. Our research aims to evaluate the connectivity of forest landscapes in the Romanian Alpine Biogeographical Region (ABR) for various terrestrial species. We analysed the distribution of forest patches and Sites of Community Importance (SCI), as part of Natura 2000 network, in the Romanian ABR. We evaluated the connectivity of forest patches for terrestrial species with different dispersal distances, identifying those patches with significant contribution to maintain the forest landscape connectivity, through the graph theory approach. To quantify the importance of each node, we evaluated the dPCconnector fraction derived from the dPC index. Of the 125 SCIs in the Romanian ABR, 71 protected areas have over 1000 ha, four of them have more than 100,000 ha. The total protected surfaces cover ~35% of the Romanian ABR, and the forest surfaces, protected in SCIs, cover 26% of the total Romanian ABR. Regarding the connectivity scores, we found that the forest surfaces across the ABR are well connected (0.89 or 1 for different dispersal distances) in comparison with the Natura 2000 forest patches. The forest patches are well connected especially for the species with large dispersal distance in both cases (d = 25 km). For the species characterized by a small dispersion distance, the connectivity is lower (0.46) in the case of protected forests. Our results evidence that the connectivity objective of the forest surfaces protected through the Nature 2000 network is not totally achieved. Furthermore new protected areas are needed where the forest are still present for increasing landscape connectivity for species. Numéro de notice : A2017-610 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.15287/afr.2016.793 En ligne : http://doi.org/10.15287/afr.2016.793 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86918
in Annals of forest research > vol 60 n° 1 (January - June 2017) . - pp 19 - 32[article]A spatial anomaly points and regions detection method using multi-constrained graphs and local density / Yan Shi in Transactions in GIS, vol 21 n° 2 (April 2017)PermalinkEtude et méthodes d'intégration et d'interaction de données 3D complexes type "nuages de points" vers un web SIG / Victor Lambert (2017)PermalinkFusion of graph embedding and sparse representation for feature extraction and classification of hyperspectral imagery / Fulin Luo in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 1 (January 2017)PermalinkPermalinkA taxonomy and survey of dynamic graph visualization / Fabian Beck in Computer graphics forum, vol 36 n° 1 (January 2017)PermalinkExtracting building patterns with multilevel graph partition and building grouping / Shihong Du in ISPRS Journal of photogrammetry and remote sensing, vol 122 (December 2016)PermalinkmR-V: Line simplification through mnemonic rasterization / Emmanuel Stefanakis in Geomatica, vol 70 n° 4 (December 2016)PermalinkThe D-FCM partitioned D-BSP tree for massive point cloud data access and rendering / Yi Zhang in ISPRS Journal of photogrammetry and remote sensing, vol 120 (october 2016)PermalinkA Topology-inferred graph-based heuristic algorithm for map simplification / QiuLei Guo in Transactions in GIS, vol 20 n° 5 (October 2016)PermalinkLocation K-anonymity in indoor spaces / Joon-Seok Kim in Geoinformatica, vol 20 n° 3 (July - September 2016)Permalink