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Points of interest recommendation from GPS trajectories / Yaqiong Liu in International journal of geographical information science IJGIS, vol 29 n° 6 (June 2015)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 29 n° 6 (June 2015) . - pp 953-979 Titre : Points of interest recommendation from GPS trajectories Type de document : Article/Communication Auteurs : Yaqiong Liu, Auteur ; Hock Soon Seah, Auteur Année de publication : 2015 Article en page(s) : pp 953-979 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] analyse de groupement [Termes IGN] calcul d'itinéraire [Termes IGN] point d'intérêt [Termes IGN] positionnement par GPS [Termes IGN] regroupement de données [Termes IGN] trajet (mobilité) [Termes IGN] utilisateur nomade [Termes IGN] visualisation simultanée Résumé : (Auteur) Recently, points of interest (POIs) recommendation has evolved into a hot research topic with real-world applications. In this paper, we propose a novel semantics-enhanced density-based clustering algorithm SEM-DTBJ-Cluster, to extract semantic POIs from GPS trajectories. We then take into account three different factors (popularity, temporal and geographical features) that can influence the recommendation score of a POI. We characterize the impacts caused by popularity, temporal and geographical information, by using different scoring functions based on three developed recommendation models. Finally, we combine the three scoring functions together and obtain a unified framework PTG-Recommend for recommending candidate POIs for a mobile user. To the best of our knowledge, this work is the first that considers popularity, temporal and geographical information together. Experimental results on two real-world data sets strongly demonstrate that our framework is robust and effective, and outperforms the baseline recommendation methods in terms of precision and recall. Numéro de notice : A2015-597 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2015.1005094 En ligne : https://doi.org/10.1080/13658816.2015.1005094 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78011 [article]

A technique for simultaneous visualization and segmentation of hyperspectral data / Abhimitra Meka in IEEE Transactions on geoscience and remote sensing, vol 53 n° 4 (April 2015)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 53 n° 4 (April 2015) . - pp 1707 - 1717 Titre : A technique for simultaneous visualization and segmentation of hyperspectral data Type de document : Article/Communication Auteurs : Abhimitra Meka, Auteur ; Subhasis Chaudhuri, Auteur Année de publication : 2015 Article en page(s) : pp 1707 - 1717 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] image hyperspectrale [Termes IGN] optimisation (mathématiques) [Termes IGN] redondance de données [Termes IGN] segmentation d'image [Termes IGN] visualisation simultanée Résumé : (Auteur) In this paper, we propose an optimization-based method for simultaneous fusion and unsupervised segmentation of hyperspectral remote sensing images by exploiting redundancy in the data. The hyperspectral data set is visualized as a single image obtained by weighted addition of all spectral points at each pixel location in the data set. The weights are optimized to improve those statistical characteristics of the fused image, which invoke an enhanced response from a human observer. A piecewise-constant smoothness constraint is imposed on the weights instead of the fused image by minimization of its 3-D total-variation norm, thus preventing the fused image from blurring. The optimal recovery of the weight matrix additionally provides useful information in segmenting the hyperspectral data set spatially. We provide ample experimental results to substantiate the usefulness of the proposed method. Numéro de notice : A2015-170 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2014.2346653 Date de publication en ligne : 04/09/2014 En ligne : https://doi.org/04/09/201410.1109/TGRS.2014.2346653 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75886 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-2015041	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Out-of-core GPU-based change detection in massive 3D point clouds / Rico Richter in Transactions in GIS, vol 17 n° 5 (October 2013)  

Public [article]  inTransactions in GIS > vol 17 n° 5 (October 2013) . - pp 724 - 741 Titre : Out-of-core GPU-based change detection in massive 3D point clouds Type de document : Article/Communication Auteurs : Rico Richter, Auteur ; Jan Eric Kiprianidis, Auteur ; Jürgen Döllner, Auteur Année de publication : 2013 Article en page(s) : pp 724 - 741 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] attribut [Termes IGN] détection de changement [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] processeur graphique [Termes IGN] semis de points [Termes IGN] structure de données localisées [Termes IGN] visualisation 3D [Termes IGN] visualisation simultanée Résumé : (Auteur) If sites, cities, and landscapes are captured at different points in time using technology such as LiDAR, large collections of 3D point clouds result. Their efficient storage, processing, analysis, and presentation constitute a challenging task because of limited computation, memory, and time resources. In this work, we present an approach to detect changes in massive 3D point clouds based on an out-of-core spatial data structure that is designed to store data acquired at different points in time and to efficiently attribute 3D points with distance information. Based on this data structure, we present and evaluate different processing schemes optimized for performing the calculation on the CPU and GPU. In addition, we present a point-based rendering technique adapted for attributed 3D point clouds, to enable effective out-of-core real-time visualization of the computation results. Our approach enables conclusions to be drawn about temporal changes in large highly accurate 3D geodata sets of a captured area at reasonable preprocessing and rendering times. We evaluate our approach with two data sets from different points in time for the urban area of a city, describe its characteristics, and report on applications. Numéro de notice : A2013-579 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01362.x Date de publication en ligne : 05/12/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01362.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32715 [article]

Adjustment computation of HASM : a high-accuracy and high speed method / T. Yue in International journal of geographical information science IJGIS, vol 24 n°11-12 (december 2010)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 24 n°11-12 (december 2010) . - pp 1725 - 1743 Titre : Adjustment computation of HASM : a high-accuracy and high speed method Type de document : Article/Communication Auteurs : T. Yue, Auteur ; Shuo Wang, Auteur Année de publication : 2010 Article en page(s) : pp 1725 - 1743 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] compensation par modèles [Termes IGN] Kansou (Chine) [Termes IGN] modèle numérique de surface [Termes IGN] modélisation 2D [Termes IGN] Setchouan (Chine) [Termes IGN] surface (géométrie) [Termes IGN] test de performance [Termes IGN] traitement de données localisées [Termes IGN] Tsinghai (Chine) [Termes IGN] visualisation simultanée Résumé : (Auteur) We developed a method for high-accuracy surface modeling (HASM) in terms of the fundamental theorem of surfaces, which has theoretically found a solution for error problems. However, the computing speed of HASM was too slow to be widely applied in practice. Thus, adjustment computation of HASM (HASM-AC) is developed in this article. For comparatively testing HASM-AC accuracy, a mathematical surface is first selected so that the true value is able to be predetermined to avoid uncontrollable data errors. The numerical test indicates that HASM-AC has the highest accuracy and its accuracy is 20.67, 15.67, and 14.67 times higher than the inverse distance weighting (IDW), kriging, and spline, respectively. Then, a 0.4 km times 0.5 km rectangular area is used to test the effects of different spatial resolutions and sampling intervals on accuracy. This real-world test demonstrates that HASM-AC accuracy increases at a much better and stable pace as the spatial resolution becomes finer and sampling intervals get shorter, compared to the classic methods. Finally, the computing speed is tested in an area with 6000 times 6000 grid cells where Qinghai, Gansu, and Sichuan provinces meet. The computing speed of HASM-AC is 11, 8, and 563 times faster than IDW, spline, and kriging, respectively, which makes HASM-AC able to process data in a huge size and make real-time visualization realizable. In short, HASM-AC performs best in both the numerical and real-world tests. Numéro de notice : A2010-550 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810903569580 En ligne : https://doi.org/10.1080/13658810903569580 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30742 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-2010071	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-2010072	RAB	Revue	Centre de documentation	En réserve L003	Disponible

An inexpensive stereo-image capture tool for motion study / A.K. Chong in Photogrammetric record, vol 22 n° 119 (September - November 2007)  

Public [article]  inPhotogrammetric record > vol 22 n° 119 (September - November 2007) . - pp 226 - 237 Titre : An inexpensive stereo-image capture tool for motion study Type de document : Article/Communication Auteurs : A.K. Chong, Auteur Année de publication : 2007 Article en page(s) : pp 226 - 237 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] caméra vidéo [Termes IGN] coût [Termes IGN] données localisées [Termes IGN] image 3D [Termes IGN] image multi sources [Termes IGN] objet mobile [Termes IGN] photogrammétrie numérique [Termes IGN] précision des mesures [Termes IGN] vidéo numérique [Termes IGN] visualisation simultanée Résumé : (Auteur) This paper discusses the evaluation of a video stereo-image capture tool for photogrammetric applications. The ‘‘NuView Adapter’’, a commonly available video-image splitting device, and a digital video camera (DV) could be used to capture stereoscopic video footage for many photogrammetric applications in which low-cost near-simultaneous stereo-images are required for 3D viewing or for 3D spatial data capture. Relevant photogrammetric applications might include: aerial surveillance, human/animal motion study (tracking), bank/security surveillance and precise 3D animation. The device permits two distinct views (left and right perspective views) to enter a single lens DV. A single convergence control in the device allows the user to obtain a stereo view of near and far objects. The system is easy to operate and the stereo-images give a good visual 3D effect. Research was carried out to determine the quality of the stereo-image for 3D measurement. The investigation involved: (1) the calibration of a customised system for optimum close range photogrammetric application; and (2) a case study involving motion tracking. A semi-automated monodigitising photogrammetric technique was used to determine the accuracy of the system. The results show that this system could achieve a spatial data accuracy of better than 13 mm at an object distance of 9 m. The horizontal and vertical accuracies are similar to those obtained by the conventional stereoscopic camera technique using a ‘‘normal case’’ configuration with 86% overlap. Copyright RS&PS + Blackwell Publishing Numéro de notice : A2007-480 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/j.1477-9730.2007.00439.x En ligne : https://doi.org/10.1111/j.1477-9730.2007.00439.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28843 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
106-07031	RAB	Revue	Centre de documentation	En réserve L003	Disponible