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An OD flow clustering method based on vector constraints: a case study for Beijing taxi origin-destination data / Xiaogang Guo in ISPRS International journal of geo-information, vol 9 n° 2 (February 2020)
[article]
Titre : An OD flow clustering method based on vector constraints: a case study for Beijing taxi origin-destination data Type de document : Article/Communication Auteurs : Xiaogang Guo, Auteur ; Zhijie Xu, Auteur ; Jianqin Zhang, Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] classification par nuées dynamiques
[Termes IGN] distance euclidienne
[Termes IGN] données de flux
[Termes IGN] données vectorielles
[Termes IGN] erreur moyenne quadratique
[Termes IGN] origine - destination
[Termes IGN] Pékin (Chine)
[Termes IGN] regroupement de données
[Termes IGN] taxi
[Termes IGN] trafic routier
[Termes IGN] zone urbaineRésumé : (auteur) Origin-destination (OD) flow pattern mining is an important research method of urban dynamics, in which OD flow clustering analysis discovers the activity patterns of urban residents and mine the coupling relationship of urban subspace and dynamic causes. The existing flow clustering methods are limited by the spatial constraints of OD points, rely on the spatial similarity of geographical points, and lack in-depth analysis of high-dimensional flow characteristics, and therefore it is difficult to find irregular flow clusters. In this paper, we propose an OD flow clustering method based on vector constraints (ODFCVC), which defines OD flow event point and OD flow vector to express the spatial location relationship and geometric flow behavior characteristics of OD flow. First, the OD flow vector coordinate system is normalized by the Euclidean distance-based OD flow event point spatial clustering, and then the OD flow clusters with similar flow patterns are mined using adjusted cosine similarity-based OD flow vector feature clustering. The transformation of OD data from point set space to vector space is realized by constraining the vector coordinate system and vector similarity through two-step clustering, which simplifies the calculation of high-dimensional similarity of OD flow and helps mining representative OD flow clusters in flow space. Due to the OD flow cluster property, the k-means algorithm is selected as the basic clustering logic in the two-step clustering method, and a sum of squared error perceptually important points algorithm considering silhouette coefficients (SSEPIP) is adopted to automatically extract the optimal cluster number without defining any parameters. Tested by origin-destination flow data in Beijing, China, new traffic flow communities based on traffic hubs are obtained by using the ODFCVC method, and irregular traffic flow clusters (including cluster mode, divergence mode, and convergence mode) with representative travel trends are found. Numéro de notice : A2020-114 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi9020128 Date de publication en ligne : 22/02/2020 En ligne : https://doi.org/10.3390/ijgi9020128 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94720
in ISPRS International journal of geo-information > vol 9 n° 2 (February 2020)[article]Multi-spectral image change detection based on single-band iterative weighting and fuzzy C-means clustering / Liyuan Ma in European journal of remote sensing, vol 53 n° 1 (2020)
[article]
Titre : Multi-spectral image change detection based on single-band iterative weighting and fuzzy C-means clustering Type de document : Article/Communication Auteurs : Liyuan Ma, Auteur ; Jia Zhenhong, Auteur ; Jie Yang, Auteur ; Nikola Kasabov, Auteur Année de publication : 2020 Article en page(s) : pp 1 -13 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] appariement d'images
[Termes IGN] bruit blanc
[Termes IGN] classification floue
[Termes IGN] classification non dirigée
[Termes IGN] coefficient de corrélation
[Termes IGN] détection de changement
[Termes IGN] distance euclidienne
[Termes IGN] image multibande
[Termes IGN] itération
[Termes IGN] masque
[Termes IGN] pondérationRésumé : (auteur) In the present study, an improved iteratively reweighted multivariate alteration detection (IR-MAD) algorithm was proposed to improve the contribution of weakly correlated bands in multi-spectral image change detection. In the proposed algorithm, each image band was given a different weight through single-band iterative weighting, improving the correlation between each pair of bands. This method was used to obtain the characteristic difference in the diagrams of the band that contain more variation information. After removing Gaussian noise from each feature-difference graph, the difference graphs of each band were fused into a change-intensity graph using the Euclidean distance formula. Finally, unsupervised fuzzy C-means (FCM) clustering was used to perform binary clustering on the fused difference graphs to obtain the change detection results. By comparing the original multivariate alteration detection (MAD) algorithm, the IR-MAD algorithm and the proposed IR-MAD algorithm, which used a mask to eliminate strong changes, the experimental results revealed that the multi-spectral change detection results of the proposed algorithm are closer to the actual value and had higher detection accuracy than the other algorithms. Numéro de notice : A2020-164 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/22797254.2019.1707124 Date de publication en ligne : 26/12/2020 En ligne : https://doi.org/10.1080/22797254.2019.1707124 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94831
in European journal of remote sensing > vol 53 n° 1 (2020) . - pp 1 -13[article]
Titre : Fast computation of distances in a tree Titre original : Calcul rapide de distances dans un arbre Type de document : Article/Communication Auteurs : Marc Pierrot-Deseilligny , Auteur Editeur : Saint-Mandé : Institut national de l'information géographique et forestière - IGN (2012-) Année de publication : 2020 Importance : 8 p. Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Algorithmique
[Termes IGN] arbre (mathématique)
[Termes IGN] distance (mathématique)Résumé : (Auteur) Computation of distances between two submits of a tree is an operation that occurs in some pattern recognition problem. When this operation has to be done thousands of times on millions of trees, the linear standard algorithms in OpN q for each pair may be a bottleneck to the global computation. This note present recursive spliting method with a complexity of OplogpN qq on each pair in worst case, and Op1q in average on all pair, once a pre-computation OpN logpN qq has been done on the whole tree. A commented C++ implementation is published as a companion to this note. Numéro de notice : P2020-004 Affiliation des auteurs : UGE-LASTIG (2020- ) Thématique : INFORMATIQUE/MATHEMATIQUE Nature : Preprint nature-HAL : Préprint DOI : sans Date de publication en ligne : 05/05/2020 En ligne : https://hal.science/hal-02563859 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95036 Documents numériques
en open access
Fast computation of distances in a tree - pdf preprintAdobe Acrobat PDF Embedding road networks and travel time into distance metrics for urban modelling / Henry Crosby in International journal of geographical information science IJGIS, Vol 33 n° 3-4 (March - April 2019)
[article]
Titre : Embedding road networks and travel time into distance metrics for urban modelling Type de document : Article/Communication Auteurs : Henry Crosby, Auteur ; theodore Damoulas, Auteur ; Stephen A. Jarvis, Auteur Année de publication : 2019 Article en page(s) : pp 512 - 536 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] covariance
[Termes IGN] distance euclidienne
[Termes IGN] durée de trajet
[Termes IGN] espace-temps
[Termes IGN] géostatistique
[Termes IGN] isométrie
[Termes IGN] krigeage
[Termes IGN] logement
[Termes IGN] modèle de simulation
[Termes IGN] réseau routier
[Termes IGN] trafic routier
[Termes IGN] urbanisme
[Termes IGN] variogrammeRésumé : (auteur) Urban environments are restricted by various physical, regulatory and customary barriers such as buildings, one-way systems and pedestrian crossings. These features create challenges for predictive modelling in urban space, as most proximity-based models rely on Euclidean (straight line) distance metrics which, given restrictions within the urban landscape, do not fully capture spatial urban processes. Here, we argue that road distance and travel time provide effective alternatives, and we develop a new low-dimensional Euclidean distance metric based on these distances using an isomap approach. The purpose of this is to produce a valid covariance matrix for Kriging. Our primary methodological contribution is the derivation of two symmetric dissimilarity matrices (B+ and B2+), with which it is possible to compute low-dimensional Euclidean metrics for the production of a positive definite covariance matrix with commonly utilised kernels. This new method is implemented into a Kriging predictor to estimate house prices on 3,669 properties in Coventry, UK. We find that a metric estimating a combination of road distance and travel time, in both R2 and R3, produces a superior house price predictor compared with alternative state-of-the-art methods, that is, a standard Euclidean metric in RN and a non-restricted road distance metric in R2 and R3. F Numéro de notice : A2019-024 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2018.1547386 Date de publication en ligne : 06/12/2018 En ligne : https://doi.org/10.1080/13658816.2018.1547386 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91952
in International journal of geographical information science IJGIS > Vol 33 n° 3-4 (March - April 2019) . - pp 512 - 536[article]Exemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-2019031 RAB Revue Centre de documentation En réserve L003 Disponible 079-2019032 RAB Revue Centre de documentation En réserve L003 Disponible Unsupervised detection of ruptures in spatial relationships in video sequences based on log‑likelihood ratio / Abdalbassir Abou-Elailah in Pattern Analysis and Applications, vol 21 n° 3 (August 2018)
[article]
Titre : Unsupervised detection of ruptures in spatial relationships in video sequences based on log‑likelihood ratio Type de document : Article/Communication Auteurs : Abdalbassir Abou-Elailah , Auteur ; Isabelle Bloch, Auteur ; Valérie Gouet-Brunet , Auteur Année de publication : 2018 Projets : 1-Pas de projet / Article en page(s) : pp 829 - 846 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] détection d'événement
[Termes IGN] distance (mathématique)
[Termes IGN] histogramme
[Termes IGN] modèle linéaire
[Termes IGN] primitive
[Termes IGN] relation spatiale
[Termes IGN] séquence d'imagesRésumé : (Auteur) In this work, we propose a new approach to automatically detect ruptures in spatial relationships in video sequences, based on low-level primitives, in unsupervised manner. The spatial relationships between two objects of interest are modeled using angle and distance histograms as examples. The evolution of the spatial relationships during time is estimated from the distances between two successive angle or distance histograms and then considered as a temporal signal. The evolution of a spatial relationship is modeled by a linear Gaussian model. Then, two hypotheses “without change” and “with change” are considered, and a log-likelihood ratio is computed. The distribution of the log-likelihood ratio, given that H0 is true, is estimated and used to compute the p value. The comparison of this p value to a significance level 훼, expressing the probability of false alarms, allows us to detect significant ruptures in spatial relationships during time. In addition, this approach is generalized to detect multiple object events such as merging, splitting, and other events that contain ruptures in their spatial relationships evolution. This work shows that the description of spatial relationships across time is a promising step toward event detection. Numéro de notice : A2017-776 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10044-017-0669-9 Date de publication en ligne : 18/11/2017 En ligne : https://doi.org/10.1007/s10044-017-0669-9 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88974
in Pattern Analysis and Applications > vol 21 n° 3 (August 2018) . - pp 829 - 846[article]Arpent : un prototype de haute exactitude pour les mesures de grande distance / Maylis Teyssendier de la Serve in XYZ, n° 154 (mars - mai 2018)PermalinkSafe separation distance score : a new metric for evaluating wildland firefighter safety zones using lidar / Michael J. Campbell in International journal of geographical information science IJGIS, vol 31 n° 7-8 (July - August 2017)PermalinkAn unsupervised two-stage clustering approach for forest structure classification based on X-band InSAR data — A case study in complex temperate forest stands / Sahra Abdullahi in International journal of applied Earth observation and geoinformation, vol 57 (May 2017)PermalinkContinuously generalizing buildings to built-up areas by aggregating and growing / Dongliang Peng (2017)PermalinkVisual analytics of delays and interaction in movement data / Maximilian Konzack in International journal of geographical information science IJGIS, vol 31 n° 1-2 (January - February 2017)PermalinkTrajectory Box Plot: a new pattern to summarize movements / Laurent Etienne in International journal of geographical information science IJGIS, vol 30 n° 5-6 (May - June 2016)PermalinkCorrection of terrestrial LiDAR intensity channel using Oren–Nayar reflectance model: An application to lithological differentiation / Dario Carrea in ISPRS Journal of photogrammetry and remote sensing, vol 113 (March 2016)PermalinkImpact de l’anisotropie du milieu dans les études de profilage géographique / Marie Trotta in Revue internationale de géomatique, vol 25 n° 4 (octobre - décembre 2015)PermalinkAn alternative method to constructing time cartograms for the visual representation of scheduled movement data / Rehmat Ullah in Journal of maps, vol 11 n° 4 ([01/08/2015])PermalinkVery high resolution image matching based on local features and k-means clustering / Amin Sedaghat in Photogrammetric record, vol 30 n° 150 (June - August 2015)Permalink