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Identification and utilization of land-use type importance for land-use data generalization / Wenxiu Gao in Cartographic journal (the), Vol 53 n° 1 (February 2016)  

Public [article]  inCartographic journal (the) > Vol 53 n° 1 (February 2016) . - pp 31 - 42 Titre : Identification and utilization of land-use type importance for land-use data generalization Type de document : Article/Communication Auteurs : Wenxiu Gao, Auteur ; Alfred Stein, Auteur ; Li Yang, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 31 - 42 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse spatiale [Termes IGN] attribut [Termes IGN] généralisation automatique de données [Termes IGN] identification automatique [Termes IGN] modèle déterministe [Termes IGN] seuillage d'image [Termes IGN] utilisation du sol [Vedettes matières IGN] Généralisation Résumé : (Auteur) A proper characterization of land-use types is critical for constructing generalization constraints to guide and control landuse data generalization. This paper focused on identification and utilization of their importance based upon land-use distributions and application themes. First, this importance was identified using a three-step method that links a diversity index, a multiple attribute decision model and a spatial association analysis. Second, with the importance, a mathematical function was designed to determine minimum area thresholds of land-use polygons as an example of generalization constraints. Third, the importance was used to assist in the selection of generalization operators and evaluation of generalization outcomes. Fourth, a land-use dataset at 1:10 000, describing the land use of a typical rural area in Hubei province of China, was generalized towards a 1:50 000 dataset to verify the effects of the presented method and function. Three additional tests were implemented to analyze the sensitivity of the importance of land-use types on setting the minimum area threshold and generalization operations. The outcome showed that the proposed methods and functions make land-use data generalization more adaptable for in-use datasets and applications. Numéro de notice : A2016-413 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/1743277413Y.0000000054 En ligne : http://dx.doi.org/10.1179/1743277413Y.0000000054 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81280 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
030-2016011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Improving representation of land-use maps derived from object-oriented image classification / Wenxiu Gao in Transactions in GIS, vol 17 n° 3 (June 2013)  

Public [article]  inTransactions in GIS > vol 17 n° 3 (June 2013) . - pp 387 - 405 Titre : Improving representation of land-use maps derived from object-oriented image classification Type de document : Article/Communication Auteurs : Wenxiu Gao, Auteur ; Alfred Stein, Auteur ; Li Yang, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 387 - 405 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] carte d'occupation du sol [Termes IGN] classification orientée objet [Termes IGN] création de zone intermédiaire [Termes IGN] généralisation cartographique [Termes IGN] lissage de données [Termes IGN] polygone [Termes IGN] précision sémantique [Termes IGN] représentation cartographique [Termes IGN] similitude [Termes IGN] système d'information géographique Résumé : (Auteur) Object-oriented (OO) image analysis provides an efficient way to generate vector-format land-cover and land-use maps from remotely sensed images. Such image-derived vector maps, however, are generally presented with congested and twisted polygons with step-like boundaries. They include unclassified polygons and polygons with geometric conflicts such as unreadable small areas and narrow corridors. The complex and poorly readable representations usually make such maps not comply well with the Gestalt principle of cartography. This article describes a framework designed to improve the representation by resolving these problematic polygons. It presents a polygon similarity model integrating semantic, geometric and spectral characteristics of the image-derived polygons to eliminate small and unclassified polygons. In addition, an outward-inward-buffering approach is presented to resolve the narrow-corridor conflicts of a polygon and improve its overall appearance. A case study demonstrates that the implementation of the framework reduces the number of the polygons by 32% and the length of the polygon boundaries by 20%. At the same time, it does not cause distinct changes the distribution of land-use types (less than 0.05%) and the overall accuracy (decreased only 0.02%) as compared with the original image-derived land-use maps. We conclude that the presented framework and models effectively improve the overall representation of image-derived maps without distinct changes in their semantic characteristics and accuracy. Numéro de notice : A2013-290 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01368.x Date de publication en ligne : 06/11/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01368.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32428 [article]

Detecting geometric conflicts for generalisation of polygonal maps / Wenxiu Gao in Cartographic journal (the), vol 49 n° 1 (February 2012)  

Public [article]  inCartographic journal (the) > vol 49 n° 1 (February 2012) . - pp 21 - 29 Titre : Detecting geometric conflicts for generalisation of polygonal maps Type de document : Article/Communication Auteurs : Wenxiu Gao, Auteur ; J. Gong, Auteur ; L. Yang, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 21 - 29 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] conflit d'espace [Termes IGN] généralisation cartographique automatisée [Termes IGN] polygone [Termes IGN] zone tampon [Vedettes matières IGN] Généralisation Résumé : (Auteur) Polygon generalisation is an essential process to produce multi-scale polygonal maps which are able to visualize categorical data at various levels of detail and with multiple themes. Detecting geometric conflicts, existing within an individual polygon and between polygons, is a primary step for polygon generalisation. This paper designs an inward-outward-buffering approach to detect narrow conflicts within an individual polygon. The approach not only detects the existence of narrow sections but also indicates their exact locations inside polygons. Another approach is presented to detect proximity conflicts in between polygons with two main steps. The first step associates buffering with an optimized proximity index to explore possible polygon clusters and spatial contexts around a problematic polygon. Based on the detected polygon clusters, the conflict regions are identified by combining outward-inward-buffering with topological operators. The tests with a real landuse dataset and two maps from other papers demonstrate that the presented approaches not only detect geometric conflict effectively, but also provide useful information for the selection of subsequent generalisation operators. Numéro de notice : A2012-169 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/1743277411Y.0000000016 Date de publication en ligne : 22/11/2013 En ligne : https://doi.org/10.1179/1743277411Y.0000000016 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31616 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
030-2012011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Robust Kalman filtering with constraints: a case study for integrated navigation / Y. Yang in Journal of geodesy, vol 84 n° 6 (June 2010)  

Public [article]  inJournal of geodesy > vol 84 n° 6 (June 2010) . - pp 373 - 381 Titre : Robust Kalman filtering with constraints: a case study for integrated navigation Type de document : Article/Communication Auteurs : Y. Yang, Auteur ; Wenxiu Gao, Auteur ; X. Zhang, Auteur Année de publication : 2010 Article en page(s) : pp 373 - 381 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] classification par maximum de vraisemblance [Termes IGN] données multicapteurs [Termes IGN] estimation statistique [Termes IGN] filtre de Kalman [Termes IGN] matrice de covariance [Termes IGN] méthode robuste [Termes IGN] positionnement cinématique [Termes IGN] positionnement intégré [Termes IGN] résidu Résumé : (Auteur) When certain constraints in the kinematic state parameters of a multi-sensor navigation system exist, they should be taken into account for the improvement of the positioning accuracy and reliability. In this paper, two types of robust estimators for integrated and two stages of Kalman filtering with state parameter constraints are derived based on the generalized maximum likelihood Lagrangian condition, respectively. The properties of the two estimators are discussed. The changes of the state estimates and their covariance matrices as well as the residual vector caused by the constraints are derived and analyzed. It is shown by a simulated example that the precision of the state estimates provided by the Kalman filtering with constraints is better than that provided by the Kalman filtering without considering the state parameter constraints; and the robust Kalman filtering with constraints further improves the reliability and robustness of the state estimates. Numéro de notice : A2010-281 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0374-6 Date de publication en ligne : 23/03/2010 En ligne : https://doi.org/10.1007/s00190-010-0374-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30475 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2010061	SL	Revue	Centre de documentation	Revues en salle	Disponible

Thematic knowledge for the generalization of land use data / Wenxiu Gao in Cartographic journal (the), vol 41 n° 3 (December 2004)  

Public [article]  inCartographic journal (the) > vol 41 n° 3 (December 2004) . - pp 245 - 252 Titre : Thematic knowledge for the generalization of land use data Type de document : Article/Communication Auteurs : Wenxiu Gao, Auteur ; J. Gong, Auteur ; Z. Li, Auteur Année de publication : 2004 Article en page(s) : pp 245 - 252 Langues : Anglais (eng) Descripteur : [Termes IGN] agriculture [Termes IGN] base de données thématiques [Termes IGN] carte topographique [Termes IGN] classification [Termes IGN] cognition [Termes IGN] connaissance thématique [Termes IGN] généralisation de base de données [Termes IGN] utilisation du sol [Vedettes matières IGN] Généralisation Résumé : (Auteur) Knowledge, especially the special knowledge about land use itself, is an indispensable component for guiding the whole process of land use data generalization. In this study, such knowledge is classified into two broad types, i.e. general knowledge and thematic knowledge. General knowledge covers the basic and common restrictions and specifications for generalization of geographic data. Thematic knowledge describes the special restrictions and specifications for a specific geographic data application. The paper emphasizes the use of thematic knowledge in detail for land use data generalization. Three main types of thematic knowledge are identified, i.e. nature-based, culture-based and application-specific. Such thematic knowledge is then represented using the so-called production-rule method to become generalization rules. These rules are built in a prototype system to guide the implementation of land use data generalization. Real-life data have been used for testing and very promising results have been obtained from this system. Numéro de notice : A2004-609 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/00087040X13959 En ligne : https://doi.org/10.1179/00087040X13959 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27125 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
030-04031	RAB	Revue	Centre de documentation	En réserve L003	Disponible