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Finding spatial outliers in collective mobility patterns coupled with social ties / Monica Wachowicz in International journal of geographical information science IJGIS, vol 30 n° 9-10 (September - October 2016)
[article]
Titre : Finding spatial outliers in collective mobility patterns coupled with social ties Type de document : Article/Communication Auteurs : Monica Wachowicz, Auteur ; Tianyu Liu, Auteur Année de publication : 2016 Article en page(s) : pp 1806 - 1831 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] centroïde
[Termes IGN] contenu généré par les utilisateurs
[Termes IGN] données issues des réseaux sociaux
[Termes IGN] données massives
[Termes IGN] interface en langage naturel
[Termes IGN] mobilité humaine
[Termes IGN] statistiques d'appels détaillés
[Termes IGN] traitement de données localisées
[Termes IGN] traitement du langage naturel
[Termes IGN] Twitter
[Termes IGN] valeur aberranteRésumé : (Auteur) Currently the increase in the variety and volume of data sources is demanding new data analytical workflows for exploring them concurrently, especially if the goal is to detect spatial outliers. In this paper, we propose a data analytical workflow for exploring Call Detail Records in conjunction with geotagged tweets. The aim was to investigate how massive data point observations can be analyzed to detect spatial outliers in collective mobility patterns that are coupled with social ties. This workflow consists of analytical tasks that are developed based on the a-priori assumption of two isometric spaces where Natural Language Processing techniques are used to find spatial clusters from geotagged tweets in a Social Space which are later used to aggregate the Call Detail Records generated by antennas located in the Mobility Space. The dynamic weighted centroids that are given by the mean location of the number of calls per hour of all antennas that belong to a particular cluster are used to compute Standard Deviation Ellipses. The longer the period of time a weighted centroid stays outside of the 99.7% probability region of an ellipse, the highest the likelihood that they are spatial outliers. The workflow was implemented for the city of Dakar in Senegal. The results indicate that the further the hourly weighted centroids are skewed from the normal mean of an ellipse, the stronger the influence of a cluster is in finding spatial outliers. Furthermore, the longer the period of time the outliers stays outside of the 99.7% probability region of an ellipse, the highest the likelihood that the outliers are genuine and can be associated to extraordinary events such as natural disasters and national holidays. Numéro de notice : A2016-569 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/SOCIETE NUMERIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2016.1144887 En ligne : http://dx.doi.org/10.1080/13658816.2016.1144887 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81713
in International journal of geographical information science IJGIS > vol 30 n° 9-10 (September - October 2016) . - pp 1806 - 1831[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-2016051 RAB Revue Centre de documentation En réserve L003 Disponible Modeling spatiotemporal topological relationships between moving object trajectories along road networks based on region connection calculus / Linbing Ma in Cartography and Geographic Information Science, Vol 43 n° 4 (September 2016)
[article]
Titre : Modeling spatiotemporal topological relationships between moving object trajectories along road networks based on region connection calculus Type de document : Article/Communication Auteurs : Linbing Ma, Auteur ; Min Deng, Auteur ; Jing Wu, Auteur ; Qiliang Liu, Auteur Année de publication : 2016 Article en page(s) : pp 346 - 360 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] Canton (Kouangtoung)
[Termes IGN] itinéraire
[Termes IGN] modèle conceptuel de données spatio-temporelles
[Termes IGN] objet mobile
[Termes IGN] relation binaire
[Termes IGN] relation topologique
[Termes IGN] segment de droite
[Termes IGN] véhicule automobileMots-clés libres : region connection calculus Résumé : (Auteur) Considering the attempts to model spatiotemporal topological relationships between moving object trajectories, the conceptual and computational framework for moving objects along a road network has not received much attention. This paper aims to draw an improved model based on Region Connection Calculus (RCC) theory to represent the spatiotemporal topological relationships between moving object trajectories along road networks. This paper first uses a dimension reduction method based on a linear-reference transformation to model the moving object trajectories segments, and then defines new time–connection and space–connection relations between two trajectory segments. On this basis, the paper proposes an extension to the RCC-based spatiotemporal binary relationship set so that the combined semantics of the spatiotemporal predicates can be described completely. A case study was carried out using Floating Car Data in Guangzhou city. The computational results show that in a real application, the occurrence frequencies of the RCC-based binary relationships are distributed nonuniformly and the semantics of some binary relationships with the highest occurrence are coarse. Therefore, the partition of the spatiotemporal connection relations and the finer aspects of the spatiotemporal relationship model may require further research work. Numéro de notice : A2016-419 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/15230406.2015.1088798 En ligne : https://doi.org/10.1080/15230406.2015.1088798 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81317
in Cartography and Geographic Information Science > Vol 43 n° 4 (September 2016) . - pp 346 - 360[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 032-2016041 RAB Revue Centre de documentation En réserve L003 Disponible Satellite images analysis for shadow detection and building height estimation / Gregoris Liasis in ISPRS Journal of photogrammetry and remote sensing, vol 119 (September 2016)
[article]
Titre : Satellite images analysis for shadow detection and building height estimation Type de document : Article/Communication Auteurs : Gregoris Liasis, Auteur ; Stavros Stavrou, Auteur Année de publication : 2016 Article en page(s) : pp 437 - 450 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] contour
[Termes IGN] délimitation
[Termes IGN] détection d'ombre
[Termes IGN] filtre spectral
[Termes IGN] hauteur du bâti
[Termes IGN] image satellite
[Termes IGN] intensité lumineuse
[Termes IGN] ombre
[Termes IGN] scène urbaine
[Termes IGN] valeur radiométriqueRésumé : (Auteur) Satellite images can provide valuable information about the presented urban landscape scenes to remote sensing and telecommunication applications. Obtaining information from satellite images is difficult since all the objects and their surroundings are presented with feature complexity. The shadows cast by buildings in urban scenes can be processed and used for estimating building heights. Thus, a robust and accurate building shadow detection process is important. Region-based active contour models can be used for satellite image segmentation. However, spectral heterogeneity that usually exists in satellite images and the feature similarity representing the shadow and several non-shadow regions makes building shadow detection challenging. In this work, a new automated method for delineating building shadows is proposed. Initially, spectral and spatial features of the satellite image are utilized for designing a custom filter to enhance shadows and reduce intensity heterogeneity. An effective iterative procedure using intensity differences is developed for tuning and subsequently selecting the most appropriate filter settings, able to highlight the building shadows. The response of the filter is then used for automatically estimating the radiometric property of the shadows. The customized filter and the radiometric feature are utilized to form an optimized active contour model where the contours are biased to delineate shadow regions. Post-processing morphological operations are also developed and applied for removing misleading artefacts. Finally, building heights are approximated using shadow length and the predefined or estimated solar elevation angle. Qualitative and quantitative measures are used for evaluating the performance of the proposed method for both shadow detection and building height estimation. Numéro de notice : A2016-792 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2016.07.006 En ligne : http://dx.doi.org/10.1016/j.isprsjprs.2016.07.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82509
in ISPRS Journal of photogrammetry and remote sensing > vol 119 (September 2016) . - pp 437 - 450[article]A simulated annealing algorithm for zoning in planning using parallel computing / Inès Santé in Computers, Environment and Urban Systems, vol 59 (September 2016)
[article]
Titre : A simulated annealing algorithm for zoning in planning using parallel computing Type de document : Article/Communication Auteurs : Inès Santé, Auteur ; Francisco F. Rivera, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 95 - 106 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] algorithme du recuit simulé
[Termes IGN] Galice (Espagne)
[Termes IGN] optimisation (mathématiques)
[Termes IGN] parcelle cadastrale
[Termes IGN] partition d'image
[Termes IGN] polygone
[Termes IGN] processeur multicoeur
[Termes IGN] utilisation du solRésumé : (auteur) There is an increasing demand for tools that support land use planning processes, particularly the design of zoning maps, which is one of the most complex tasks in the field. In this task, different land use categories need to be allocated according to multiple criteria. The problem can be formalized in terms of a multiobjective problem. This paper generalizes and complements a previous work on this topic. It presents an algorithm based on a simulated annealing heuristic that optimizes the delimitation of land use categories on a cadastral parcel map according to suitability and compactness criteria. The relative importance of both criteria can be adapted to any particular case. Despite its high computational cost, the use of plot polygons was decided because it is realistic in terms of technical application and land use laws. Due to the computational costs of our proposal, parallel implementations are required, and several approaches for shared memory systems such as multicores are analysed in this paper. Results on a real case study conducted in the Spanish municipality of Guitiriz show that the parallel algorithm based on simulated annealing is a feasible method to design alternative zoning maps. Comparisons with results from experts are reported, and they show a high similarity. Results from our strategy outperform those by experts in terms of suitability and compactness. The parallel version of the code produces good results in terms of speed-up, which is crucial for taking advantage of the architecture of current multicore processors. Numéro de notice : A2016-407 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.compenvurbsys.2016.05.005 Date de publication en ligne : 10/06/2016 En ligne : http://dx.doi.org/10.1016/j.compenvurbsys.2016.05.005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81240
in Computers, Environment and Urban Systems > vol 59 (September 2016) . - pp 95 - 106[article]Assessment of vertical TEC mapping functions for space-based GNSS observations / Jiahao Zhong in GPS solutions, vol 20 n° 3 (July 2016)
[article]
Titre : Assessment of vertical TEC mapping functions for space-based GNSS observations Type de document : Article/Communication Auteurs : Jiahao Zhong, Auteur ; Jiuhou Lei, Auteur ; Xiankang Dou, Auteur ; Xinan Yue, Auteur Année de publication : 2016 Article en page(s) : pp 353 - 362 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] centroïde
[Termes IGN] coordonnées GNSS
[Termes IGN] hauteur de la couche ionosphérique
[Termes IGN] ionosphère
[Termes IGN] orbite basse
[Termes IGN] teneur totale en électrons
[Termes IGN] teneur verticale totale en électronsRésumé : (Auteur) The mapping function is commonly used to convert slant to vertical total electron content (TEC) based on the assumption that the ionospheric electrons concentrate in a layer. The height of the layer is called ionospheric effective height (IEH) or shell height. The mapping function and IEH are generally well understood for ground-based global navigation satellite system (GNSS) observations, but they are rarely studied for the low earth orbit (LEO) satellite-based TEC conversion. This study is to examine the applicability of three mapping functions for LEO-based GNSS observations. Two IEH calculating methods, namely the centroid method based on the definition of the centroid and the integral method based on one half of the total integral, are discussed. It is found that the IEHs increase linearly with the orbit altitudes ranging from 400 to 1400 km. Model simulations are used to compare the vertical TEC converted by these mapping functions and the vertical TEC directly calculated by the model. Our results illustrate that the F&K (Foelsche and Kirchengast) geometric mapping function together with the IEH from the centroid method is more suitable for the LEO-based TEC conversion, though the thin layer model along with the IEH of the integral method is more appropriate for the ground-based vertical TEC retrieval. Numéro de notice : A2016-629 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0444-6 En ligne : http://dx.doi.org/10.1007/s10291-015-0444-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81832
in GPS solutions > vol 20 n° 3 (July 2016) . - pp 353 - 362[article]A point-based methodology for the automatic positional accuracy assessment of geospatial databases / Juan J. Ruiz-Lendínez in Survey review, vol 48 n° 349 (July 2016)PermalinkUsing classification trees to predict forest structure types from LiDAR data / Chiara Torresan in Annals of forest research, vol 59 n° 2 (July - December 2016)PermalinkAn improved ANUDEM method combining topographic correction and DEM interpolation / Xianwei Zheng in Geocarto international, vol 31 n° 5 - 6 (May - June 2016)PermalinkBarycentre method for solving distance equations / X. Shuqiang in Survey review, vol 48 n° 348 (May 2016)PermalinkRobust approximation of the Medial Axis Transform of LiDAR point clouds as a tool for visualisation / Ravi Peters in Computers & geosciences, vol 90 part A (May 2016)PermalinkThe reliability of RANSAC method when estimating the parameters of geometric object / Tilen Urbančič in Geodetski vestnik, vol 60 n° 1 (March - May 2016)Permalinkµ-shapes: Delineating urban neighborhoods using volunteered geographic information / Matt Aadland in Journal of Spatial Information Science (JoSIS), n° 12 (March 2016)PermalinkPermalinkFusion of hyperspectral images and digital surface models for urban object extraction / Janja Avbelj (2016)PermalinkIndoor navigation of mobile robots based on visual memory and image-based visual servoing / Suman Raj Bista (2016)PermalinkPhotogrammetric computer vision / Wolfgang Förstner (2016)PermalinkA robust mosaicking procedure for high spatial resolution remote sensing images / Xinghua Li in ISPRS Journal of photogrammetry and remote sensing, vol 109 (November 2015)PermalinkMorphing linear features based on their entire structures / Min Deng in Transactions in GIS, vol 19 n° 5 (October 2015)PermalinkPolygonal clustering analysis using multilevel graph-partition / Wanyi Wang in Transactions in GIS, vol 19 n° 5 (October 2015)PermalinkSELF: Semantically Enriched Line simpliFication / Emmanuel Stefanakis in International journal of geographical information science IJGIS, vol 29 n° 10 (October 2015)PermalinkContextual Douglas-Peucker Simplification / Titus Tienaah in Geomatica, vol 69 n° 3 (september 2015)PermalinkIllustration 3D de la Méthode du Plan des Sommets pour la détermination du point au large / Yves Robin-Jouan in Navigation aérienne, maritime, spatiale, terrestre, vol 62 n° 248 (septembre 2015)PermalinkMatérialisation de cubes de données par des partitions d’ensembles de n-uplets / Frédéric Dumonceaux in Ingénierie des systèmes d'information, ISI : Revue des sciences et technologies de l'information, RSTI, vol 20 n° 5 (septembre - octobre 2015)PermalinkIntegrative representation and inference of qualitative locations about points, lines, and polygons / Shihong Du in International journal of geographical information science IJGIS, vol 29 n° 6 (June 2015)PermalinkSemi-automated building footprint extraction from orthophotos / Rheannon Brooks in Geomatica, vol 69 n° 2 (June 2015)Permalink