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Triangulation method for area-line geometry-type changes in map generalisation / H. Selvi in Cartographic journal (the), vol 47 n° 2 (May 2010)
[article]
Titre : Triangulation method for area-line geometry-type changes in map generalisation Type de document : Article/Communication Auteurs : H. Selvi, Auteur ; O. Bildirici, Auteur ; M. Yerci, Auteur Année de publication : 2010 Article en page(s) : pp 157 - 163 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] axe médian
[Termes IGN] données vectorielles
[Termes IGN] généralisation cartographique automatisée
[Termes IGN] modèle topologique spaghetti
[Termes IGN] système d'information géographique
[Termes IGN] triangulation de Delaunay
[Termes IGN] Visual Basic
[Vedettes matières IGN] GénéralisationRésumé : (Auteur) Changes in object geometry-type such as area to line are necessary in terms of the requirements of cartographic generalisation, and also for the creation of the network topology in geographical information systems. Geometry-type changes that reduce dimension include area-line, area-point and line-point changes. This study focuses on area-line changes. Since the area objects have different shapes, there is no unique solution that works in all possible situations. Well-known methods for area-line changes include triangulation, water lining, straight skeletons, etc. In this paper, an approach based on triangulation is introduced for creating road centerlines from blocks of parcels. Spaghetti large-scale map data are taken into consideration in this approach in which blocks of parcels are captured as polygons and roads are represented by the space between them. In order to implement this approach, a subprogram (script) is developed under the NETCAD software package - a Turkish CAD-GIS software package - with the Visual Basic scripting language. This subprogram also includes post-processing routines for the relevant node creation at road crossings, and delivers acceptable results for the centerlines; however, the post-processing needs to be improved. Numéro de notice : A2010-261 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/000870409X12584524218965 Date de publication en ligne : 18/07/2013 En ligne : https://doi.org/10.1179/000870409X12584524218965 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30455
in Cartographic journal (the) > vol 47 n° 2 (May 2010) . - pp 157 - 163[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 030-2010021 RAB Revue Centre de documentation En réserve L003 Disponible Visualisation of origins, destinations and flows with OD maps / J. Wood in Cartographic journal (the), vol 47 n° 2 (May 2010)
[article]
Titre : Visualisation of origins, destinations and flows with OD maps Type de document : Article/Communication Auteurs : J. Wood, Auteur ; A. Slingsby, Auteur ; Jason Dykes, Auteur Année de publication : 2010 Article en page(s) : pp 117 - 129 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] arc
[Termes IGN] cartographie des flux
[Termes IGN] cartographie dynamique
[Termes IGN] généralisation cartographique automatisée
[Termes IGN] matrice
[Termes IGN] migration humaine
[Termes IGN] trajectographie (positionnement)
[Termes IGN] visualisation cartographique
[Termes IGN] visualisation de donnéesRésumé : (Auteur) We present a new technique for the visual exploration of origins (O) and destinations (D) arranged in geographic space. Previous attempts to map the flows between origins and destinations have suffered from problems of occlusion usually requiring some form of generalisation, such as aggregation or flow density estimation before they can be visualized. This can lead to loss of detail or the introduction of arbitrary artefacts in the visual representation. Here, we propose mapping OD vectors as cells rather than lines, comparable with the process of constructing OD matrices, but unlike the OD matrix, we preserve the spatial layout of all origin and destination locations by constructing a gridded two-level spatial treemap. The result is a set of spatially ordered small multiples upon which any arbitrary geographic data may be projected. Using a hash grid spatial data structure, we explore the characteristics of the technique through a software prototype that allows interactive query and visualisation of 105-106 simulated and recorded OD vectors. The technique is illustrated using US county to county migration and commuting statistics. Copyright British Cartographic Society Numéro de notice : A2010-258 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/000870410X12658023467367 Date de publication en ligne : 18/07/2013 En ligne : https://doi.org/10.1179/000870410X12658023467367 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30452
in Cartographic journal (the) > vol 47 n° 2 (May 2010) . - pp 117 - 129[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 030-2010021 RAB Revue Centre de documentation En réserve L003 Disponible Algorithms for constrained k-nearest neighbor queries over moving object trajectories / Yunjun Gao in Geoinformatica, vol 14 n° 2 (April 2010)
[article]
Titre : Algorithms for constrained k-nearest neighbor queries over moving object trajectories Type de document : Article/Communication Auteurs : Yunjun Gao, Auteur ; B. Zheng, Auteur ; G. Chen, Auteur ; Qi Li, Auteur Année de publication : 2010 Article en page(s) : pp 241 - 276 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] arbre-R
[Termes IGN] base de données d'objets mobiles
[Termes IGN] base de données spatiotemporelles
[Termes IGN] classification barycentrique
[Termes IGN] objet mobile
[Termes IGN] processus spatial
[Termes IGN] programmation par contraintes
[Termes IGN] requête spatialeRésumé : (Auteur) An important query for spatio-temporal databases is to find nearest trajectories of moving objects. Existing work on this topic focuses on the closest trajectories in the whole data space. In this paper, we introduce and solve constrained k-nearest neighbor (CkNN) queries and historical continuous CkNN (HCCkNN) queries on R-tree-like structures storing historical information about moving object trajectories. Given a trajectory set D, a query object (point or trajectory) q, a temporal extent T, and a constrained region CR, (i) a CkNN query over trajectories retrieves from D within T, the k (? 1) trajectories that lie closest to q and intersect (or are enclosed by) CR; and (ii) an HCCkNN query on trajectories retrieves the constrained k nearest neighbors (CkNNs) of q at any time instance of T. We propose a suite of algorithms for processing CkNN queries and HCCkNN queries respectively, with different properties and advantages. In particular, we thoroughly investigate two types of CkNN queries, i.e., CkNNP and CkNNT, which are defined with respect to stationary query points and moving query trajectories, respectively; and two types of HCCkNN queries, namely, HCCkNNP and HCCkNNT, which are continuous counterparts of CkNNP and CkNNT, respectively. Our methods utilize an existing data-partitioning index for trajectory data (i.e., TB-tree) to achieve low I/O and CPU cost. Extensive experiments with both real and synthetic datasets demonstrate the performance of the proposed algorithms in terms of efficiency and scalability. Copyright Springer Numéro de notice : A2010-067 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-009-0084-5 Date de publication en ligne : 28/04/2009 En ligne : https://doi.org/10.1007/s10707-009-0084-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30263
in Geoinformatica > vol 14 n° 2 (April 2010) . - pp 241 - 276[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 057-2010021 RAB Revue Centre de documentation En réserve L003 Disponible Estimating crown base height for Scots pine by means of the 3D geometry of airborne laser scanning data / Jari Vauhkonen in International Journal of Remote Sensing IJRS, vol 31 n° 5 (March 2010)
[article]
Titre : Estimating crown base height for Scots pine by means of the 3D geometry of airborne laser scanning data Type de document : Article/Communication Auteurs : Jari Vauhkonen, Auteur Année de publication : 2010 Conférence : Silvilaser 2008, 8th international conference on Lidar applications in forest assessment and inventory 17/09/2008 19/09/2008 Edimbourg Royaume-Uni Proceedings Taylor&Francis Article en page(s) : pp 1213 - 1226 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] croissance des arbres
[Termes IGN] données laser
[Termes IGN] données localisées 3D
[Termes IGN] estimation statistique
[Termes IGN] géomètrie algorithmique
[Termes IGN] hauteur des arbres
[Termes IGN] houppier
[Termes IGN] lasergrammétrie
[Termes IGN] modélisation 3D
[Termes IGN] Pinus sylvestris
[Termes IGN] régression linéaire
[Termes IGN] sylviculture
[Termes IGN] télémétrie laser aéroporté
[Termes IGN] triangulation de DelaunayRésumé : (Auteur) Crown base height (CBH) is an important factor in relation to several characteristics of the tree stock. This paper introduces approaches for estimating tree-level CBH from airborne laser scanning (ALS) data that make use of features of computational geometry. For that purpose, the concepts of Delaunay triangulations and alpha shapes were applied and compared with approaches based on analysing return frequencies and predicting CBH by linear regression. These approaches were evaluated using test data on a total of 185 Scots pine trees, of which 136 were of sawlog size, that were detected and delineated from ALS data with a density of approximately 4 returns m-2. The results suggest that variables based on the frequencies of crown returns within predefined height bins are the most accurate for estimating CBH. By combining the best CBH estimate with the estimated tree height in linear regression, a root mean squared error (RMSE) of 1.4 m (14%) was achieved when all study trees were considered. The estimation was generally less accurate for the trees smaller than those of sawlog size. Although the accuracy of estimating CBH is lower using the three-dimensional (3D) geometry approaches presented here, they are considered to have potential for further development. Numéro de notice : A2010-252 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160903380615 En ligne : https://doi.org/10.1080/01431160903380615 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30446
in International Journal of Remote Sensing IJRS > vol 31 n° 5 (March 2010) . - pp 1213 - 1226[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-2010031 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Delineation and geometric modeling of road networks / C. Poullis in ISPRS Journal of photogrammetry and remote sensing, vol 65 n° 2 (March - April 2010)
[article]
Titre : Delineation and geometric modeling of road networks Type de document : Article/Communication Auteurs : C. Poullis, Auteur ; S. You, Auteur Année de publication : 2010 Article en page(s) : pp 165 - 181 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] arc
[Termes IGN] axe médian
[Termes IGN] données lidar
[Termes IGN] extraction automatique
[Termes IGN] filtre de Gabor
[Termes IGN] image satellite
[Termes IGN] photographie aérienne
[Termes IGN] regroupement de données
[Termes IGN] réseau routierRésumé : (Auteur) In this work we present a novel vision-based system for automatic detection and extraction of complex road networks from various sensor resources such as aerial photographs, satellite images, and LiDAR. Uniquely, the proposed system is an integrated solution that merges the power of perceptual grouping theory (Gabor filtering, tensor voting) and optimized segmentation techniques (global optimization using graph-cuts) into a unified framework to address the challenging problems of geospatial feature detection and classification. Firstly, the local precision of the Gabor filters is combined with the global context of the tensor voting to produce accurate classification of the geospatial features. In addition, the tensorial representation used for the encoding of the data eliminates the need for any thresholds, therefore removing any data dependencies. Secondly, a novel orientation-based segmentation is presented which incorporates the classification of the perceptual grouping, and results in segmentations with better defined boundaries and continuous linear segments. Finally, a set of gaussian-based filters are applied to automatically extract centerline information (magnitude, width and orientation). This information is then used for creating road segments and transforming them to their polygonal representations. Numéro de notice : A2010-091 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2009.10.004 En ligne : https://doi.org/10.1016/j.isprsjprs.2009.10.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30287
in ISPRS Journal of photogrammetry and remote sensing > vol 65 n° 2 (March - April 2010) . - pp 165 - 181[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2010021 SL Revue Centre de documentation Revues en salle Disponible Un graphe génératif pour la classification semi-supervisée / P. Gaillard in Ingénierie des systèmes d'information, ISI : Revue des sciences et technologies de l'information, RSTI, vol 15 n° 2 (mars - avril 2010)PermalinkSegmentation and reconstruction of polyhedral building roofs from aerial lidar points clouds / A. Sampath in IEEE Transactions on geoscience and remote sensing, vol 48 n° 3 Tome 2 (March 2010)PermalinkGeoGraphLab: a tool for exploring structural characteristics of transportation network / Eric Mermet (2010)PermalinkLimites, applications continues, espaces complets / D. Sondaz (2010)PermalinkModelling three-dimensional geoscientific datasets with the discrete Voronoi diagram / T. Van Der Putte (2010)PermalinkPermalinkSimulation des systèmes complexes en géographie / P. Langlois (2010)PermalinkPermalinkDéfinition des risques encourus par des pylônes électriques au moyen de l'évolution de l'érosion / G. Clasen Wosny in XYZ, n° 121 (décembre 2009 - février 2010)PermalinkDeveloping an adaptive topological tessellation for 3D modeling in geosciences / L. Hashemi Beni in Geomatica, vol 63 n° 4 (December 2009)Permalink