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Location-based anonymization: comparison and evaluation of the Voronoi-based aggregation system / William Lee Croft in International journal of geographical information science IJGIS, vol 30 n° 11-12 (November - December 2016)
[article]
Titre : Location-based anonymization: comparison and evaluation of the Voronoi-based aggregation system Type de document : Article/Communication Auteurs : William Lee Croft, Auteur ; Wei Shi, Auteur ; Jörg-Rüdiger Sack, Auteur ; Jean-Pierre Corriveau, Auteur Année de publication : 2016 Article en page(s) : pp 2253 - 2275 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique
[Termes IGN] anonymisation
[Termes IGN] diagramme de Voronoï
[Termes IGN] partitionnement
[Termes IGN] santé
[Termes IGN] service fondé sur la positionRésumé : (Auteur) Hospitals and health care organizations collect large amounts of detailed health care data that is in high demand by researchers. Thus, the possessors of such data are in need of methods that allow for this data to be released without compromising the confidentiality of the individuals to whom it pertains. As the geographic aspect of this data is becoming increasingly relevant for research being conducted, it is important for an anonymization process to pay due attention to the geographic attributes of such data. In this paper, a novel system for health care data anonymization is presented. At the core of the system is the aggregation of an initial regionalization guided by the use of a Voronoi diagram. We conduct a comparison with another location-based system of anonymization, GeoLeader. We show that our system is capable of producing results of a comparable quality with a much faster running time. Numéro de notice : A2016-753 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2016.1170836 En ligne : http://dx.doi.org/10.1080/13658816.2016.1170836 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82414
in International journal of geographical information science IJGIS > vol 30 n° 11-12 (November - December 2016) . - pp 2253 - 2275[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 079-2016061 RAB Revue Centre de documentation En réserve L003 Disponible Skeletal camera network embedded structure-from-motion for 3D scene reconstruction from UAV images / Zhihua Xua in ISPRS Journal of photogrammetry and remote sensing, vol 121 (November 2016)
[article]
Titre : Skeletal camera network embedded structure-from-motion for 3D scene reconstruction from UAV images Type de document : Article/Communication Auteurs : Zhihua Xua, Auteur ; Lixin Wud, Auteur ; Markus Gerke, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 113 - 127 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] appariement de points
[Termes IGN] connexité (topologie)
[Termes IGN] drone
[Termes IGN] prise de vue aérienne
[Termes IGN] reconstruction 3D
[Termes IGN] squelettisation
[Termes IGN] structure-from-motion
[Termes IGN] topologieRésumé : (Auteur) Structure-from-Motion (SfM) techniques have been widely used for 3D scene reconstruction from multi-view images. However, due to the large computational costs of SfM methods there is a major challenge in processing highly overlapping images, e.g. images from unmanned aerial vehicles (UAV). This paper embeds a novel skeletal camera network (SCN) into SfM to enable efficient 3D scene reconstruction from a large set of UAV images. First, the flight control data are used within a weighted graph to construct a topologically connected camera network (TCN) to determine the spatial connections between UAV images. Second, the TCN is refined using a novel hierarchical degree bounded maximum spanning tree to generate a SCN, which contains a subset of edges from the TCN and ensures that each image is involved in at least a 3-view configuration. Third, the SCN is embedded into the SfM to produce a novel SCN-SfM method, which allows performing tie-point matching only for the actually connected image pairs. The proposed method was applied in three experiments with images from two fixed-wing UAVs and an octocopter UAV, respectively. In addition, the SCN-SfM method was compared to three other methods for image connectivity determination. The comparison shows a significant reduction in the number of matched images if our method is used, which leads to less computational costs. At the same time the achieved scene completeness and geometric accuracy are comparable. Numéro de notice : A2016--016 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2016.08.013 En ligne : https://doi.org/10.1016/j.isprsjprs.2016.08.013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83878
in ISPRS Journal of photogrammetry and remote sensing > vol 121 (November 2016) . - pp 113 - 127[article]The 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)
[article]
Titre : The D-FCM partitioned D-BSP tree for massive point cloud data access and rendering Type de document : Article/Communication Auteurs : Yi Zhang, Auteur Année de publication : 2016 Article en page(s) : pp 25 - 36 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] analyse en composantes principales
[Termes IGN] arbre BSP
[Termes IGN] classification floue
[Termes IGN] densité des points
[Termes IGN] semis de points
[Termes IGN] traitement de semis de points
[Termes IGN] valeur propreRésumé : (Auteur) The spatial partitioning of massive point cloud data involves dividing the space into a multi-tree structure step by step, so as to achieve the purpose of fast access and to render the point cloud. The current methods are based on spatial regularity and equal division, which is not consistent with the irregular and non-uniform distribution of most point clouds. This paper presents a directional fuzzy c-means (D-FCM) method for irregular spatial partitioning. The distance metric is weighted by a direction coefficient, which is determined by the eigenvalue of the point cloud. The orientation of each node is adaptively calculated by principal component analysis of the point cloud, and Karhunen-Loeve (KL) transform is applied to the points coordinates in node. A binary space partitioning (BSP) tree structure is used to partition the point cloud data node by node, and a directional BSP (D-BSP) tree is formed. The D-BSP tree structure was tested with point clouds of 0.1 million to over 2 billion points (up to 60 GB). The experimental results showed that the D-BSP tree can ensure that the bounding boxes are close to the actual spatial distribution of the point cloud, it can completely expand along the spatial configuration of the point cloud without generating unnecessary partitioning, and it can achieve a higher rendering speed with less memory requirement. Numéro de notice : A2016-795 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2016.08.002 En ligne : https://doi.org/10.1016/j.isprsjprs.2016.08.002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82529
in ISPRS Journal of photogrammetry and remote sensing > vol 120 (october 2016) . - pp 25 - 36[article]A Topology-inferred graph-based heuristic algorithm for map simplification / QiuLei Guo in Transactions in GIS, vol 20 n° 5 (October 2016)
[article]
Titre : A Topology-inferred graph-based heuristic algorithm for map simplification Type de document : Article/Communication Auteurs : QiuLei Guo, Auteur ; Hassan A. Karimi, Auteur Année de publication : 2016 Article en page(s) : pp 775 – 789 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] algorithme de généralisation
[Termes IGN] carte heuristique
[Termes IGN] graphe
[Termes IGN] méthode heuristique
[Termes IGN] polyligne
[Termes IGN] relation topologique
[Termes IGN] temps réel
[Termes IGN] voisinage (relation topologique)
[Vedettes matières IGN] GénéralisationRésumé : (auteur) In this article, we present a heuristic map simplification algorithm based on a novel topology-inferred graph model. Compared with the existing algorithms, which only focus either on geometry simplification or on topological consistency, our algorithm simplifies the map composed of series of polylines and constraint points while maintaining the topological relationships in the map, maximizing the number of removal points, and minimizing error distance efficiently. Unlike some traditional geometry simplification algorithms, such as Douglas and Peucker's, which add points incrementally, we remove points sequentially based on a priority determined by heuristic functions. In the first stage, we build a graph to model the topology of points in the map from which we determine whether a point is removable or not. As map generalization is needed in different applications with different requirements, we present two heuristic functions to determine the priority of points removal for two different purposes: to save storage space and to reduce computation time. The time complexity of our algorithm is math formula which is efficient enough to be considered for real-time applications. Experiments on real maps were conducted and the results indicate that our algorithm produces high quality results; one heuristic function results in higher removal points saving storage space and the other improves the time performance significantly. Numéro de notice : A2016-999 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/tgis.12188 En ligne : http://dx.doi.org/10.1111/tgis.12188 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83779
in Transactions in GIS > vol 20 n° 5 (October 2016) . - pp 775 – 789[article]Building displacement based on the topological structure / Yageng Sun in Cartographic journal (the), Vol 53 n° 3 (August 2016)
[article]
Titre : Building displacement based on the topological structure Type de document : Article/Communication Auteurs : Yageng Sun, Auteur ; Qingsheng Guo, Auteur ; Yuangang Liu, Auteur ; et al., Auteur Année de publication : 2016 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] algorithme snake
[Termes IGN] déplacement d'objet géographique
[Termes IGN] généralisation automatique de données
[Termes IGN] optimisation (mathématiques)
[Termes IGN] partitionnement
[Termes IGN] pondération
[Termes IGN] relation spatiale
[Termes IGN] triangulation de Delaunay
[Vedettes matières IGN] GénéralisationRésumé : (auteur) Map data at smaller scales than their source can result in spatial conflict, whereby map symbols become too close, or overlaid. Server map generalisation operators may be applied to solve this problem, including displacement. In this paper, we show how an optimisation algorithm, the snake algorithm, was used to displace multiple objects in order to resolve spatial conflicts and maintain important spatial relationships between objects during displacement. Two principles based on the snake algorithm are proposed in this paper. First, the truss structure mirroring spatial proximity relationships between buildings and between building and road is formed based on the weighted proximity graph derived from constrained Delaunay triangulations (CDT) in each map partition. In the weighted proximity graph, each connecting line is determined as a snake and as an element unit to assemble the global stiffness matrix in snake algorithm. Second, a buffer method that calculates force between a building and a road (or other linear features) or between pair of buildings is adopted in the snake algorithm. This avoids the imbalance phenomenon caused by different force calculation methods during the displacement. The feasibility of the approach is demonstrated in obtaining real geographic data. Finally, the results are cartographically usable and in particular, the spatial relationships between objects are preserved. Numéro de notice : A2016-680 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/1743277414Y.0000000089 En ligne : http://dx.doi.org/10.1179/1743277414Y.0000000089 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81937
in Cartographic journal (the) > Vol 53 n° 3 (August 2016)[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 030-2016031 RAB Revue Centre de documentation En réserve L003 Disponible Improved progressive TIN densification filtering algorithm for airborne LiDAR data in forested areas / Xiaoqian Zhao in ISPRS Journal of photogrammetry and remote sensing, vol 117 (July 2016)PermalinkLocation K-anonymity in indoor spaces / Joon-Seok Kim in Geoinformatica, vol 20 n° 3 (July - September 2016)PermalinkSparse and low-rank graph for discriminant analysis of hyperspectral imagery / Wei Li in IEEE Transactions on geoscience and remote sensing, vol 54 n° 7 (July 2016)PermalinkSplitArea: an algorithm for weighted splitting of faces in the context of a planar partition / Martijn Meijers in International journal of geographical information science IJGIS, vol 30 n° 7- 8 (July - August 2016)PermalinkComment concevoir des continuités écologiques en milieu urbain ? / Eugénie Schwoertzig in Sciences, eaux & territoires, article hors série n° 26 (hors-série 2016)PermalinkQualitative spatial logics for buffered geometries / Heshan Du in Journal of Artificial Intelligence Research, vol 56 (May - August 2016)PermalinkHybrid terrain rendering based on the external edge primitive / E.G. Paredes in International journal of geographical information science IJGIS, vol 30 n° 5-6 (May - June 2016)PermalinkLeveraging efficient indexing schema to support multigraph query answering / Vijay Ingalalli in Ingénierie des systèmes d'information, ISI : Revue des sciences et technologies de l'information, RSTI, vol 21 n° 3 (mai - juin 2016)PermalinkReconstruction of itineraries from annotated text with an informed spanning tree algorithm / Ludovic Moncla in International journal of geographical information science IJGIS, vol 30 n° 5-6 (May - June 2016)PermalinkStorm event representation and analysis based on a directed spatiotemporal graph model / W. Liu in International journal of geographical information science IJGIS, vol 30 n° 5-6 (May - June 2016)Permalink