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Semisupervised classification of remote sensing images with active queries / Jordi Munoz-Mari in IEEE Transactions on geoscience and remote sensing, vol 50 n° 10 Tome 1 (October 2012)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 50 n° 10 Tome 1 (October 2012) . - pp 3751 - 3763 Titre : Semisupervised classification of remote sensing images with active queries Type de document : Article/Communication Auteurs : Jordi Munoz-Mari, Auteur ; Devis Tuia, Auteur ; G. Camps-Valls, Auteur Année de publication : 2012 Article en page(s) : pp 3751 - 3763 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes descripteurs IGN] analyse de groupement [Termes descripteurs IGN] apprentissage (cognition) [Termes descripteurs IGN] carte d'occupation du sol [Termes descripteurs IGN] carte de confiance [Termes descripteurs IGN] classification semi-dirigée [Termes descripteurs IGN] image multibande [Termes descripteurs IGN] occupation du sol [Termes descripteurs IGN] requête spatiale [Termes descripteurs IGN] télédétection spatiale Résumé : (Auteur) We propose a semiautomatic procedure to generate land cover maps from remote sensing images. The proposed algorithm starts by building a hierarchical clustering tree, and exploits the most coherent pixels with respect to the available class information. For a given amount of labeled pixels, the algorithm returns both classification and confidence maps. Since the quality of the map depends of the number and informativeness of the labeled pixels, active learning methods are used to select the most informative samples to increase confidence in class membership. Experiments on four different data sets, accounting for hyperspectral and multispectral images at different spatial resolutions, confirm the effectiveness of the proposed approach, and how active learning techniques reduce the uncertainty of the classification maps. Specifically, more accurate results with fewer labeled samples are obtained. Inclusion of spatial information in the classifiers drastically improves the classification accuracy, leading to faster convergence curves and tighter confidence intervals. In conclusion, the presented algorithm provides efficient image classification and, at the same time, yields a confidence map that may be very useful in many Earth observation applications. Numéro de notice : A2012-524 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2185504 date de publication en ligne : 08/03/2012 En ligne : https://doi.org/10.1109/TGRS.2012.2185504 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31970 [article]

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Topological operators: a relaxed query processing approach / Alberto Belussi in Geoinformatica, vol 16 n° 1 (January 2012)  

Public [article]  inGeoinformatica > vol 16 n° 1 (January 2012) . - pp 67 - 110 Titre : Topological operators: a relaxed query processing approach Type de document : Article/Communication Auteurs : Alberto Belussi, Auteur ; Barbara Catania, Auteur ; P. Podesta, Auteur Année de publication : 2012 Article en page(s) : pp 67 - 110 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes descripteurs IGN] opérateur spatial [Termes descripteurs IGN] relation topologique [Termes descripteurs IGN] requête spatiale Résumé : (Auteur) Relaxation and approximation techniques have been proposed as approaches for improving the quality of query results, in terms of completeness and accuracy, in environments where the user may not be able to specify the query in a complete and exact way, since data are quite heterogeneous or she may not know all the characteristics of data at hand. This problem, mainly addressed for relational and XML data, is nowadays quite relevant also for geo-spatial data, due to their increasing usage in highly critical decisional processes. Among geo-spatial queries, those based on spatial and more precisely topological relations are currently used in an increasing number of applications. As far as we know, no approach has been proposed so far for relaxing queries based on topological predicates when they return an empty or insufficient answer, in order to improve result quality and user satisfaction. In this paper, we consider this problem and we present a general relaxation strategy for, possibly multi-domain, topological selection and join queries. Two specific semantics are also provided: the first applies the minimum amount of relaxation in order to get an acceptable answer; the second relaxes the given query of a certain fixed amount, depending on the considered topological predicate. Index-based processing algorithms, for efficiently executing relaxed queries based on the proposed semantics, are also presented and a specific topological similarity function, to be used for relaxation purposes, is proposed. Experimental results show that the overhead given by query relaxation is acceptable. Numéro de notice : A2012-082 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-011-0124-9 date de publication en ligne : 10/05/2011 En ligne : https://doi.org/10.1007/s10707-011-0124-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31530 [article]

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PostGIS pour les néophytes (6ème partie) : Le langage PL/PgSQL / Anonyme in Géomatique expert, n° 82 (01/09/2011)

Public [article]  inGéomatique expert > n° 82 (01/09/2011) . - pp 18 - 23 Titre : PostGIS pour les néophytes (6ème partie) : Le langage PL/PgSQL Type de document : Article/Communication Auteurs : Anonyme, Auteur Année de publication : 2011 Article en page(s) : pp 18 - 23 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes descripteurs IGN] distance de Hausdorff [Termes descripteurs IGN] PL/SQL [Termes descripteurs IGN] PostGIS [Termes descripteurs IGN] PostgreSQL [Termes descripteurs IGN] requête spatiale Résumé : (Auteur) Ce nouveau volet constitue une introduction à la programmation PostGreSQL/PostGIS : comment créer des fonctions complexes qui ne sont pas fournies avec la cartouche spatiale et les utiliser pour réaliser des requêtes élaborées ? Numéro de notice : A2011-369 Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31148 [article]

Voir aussi

• PostGIS pour les néophytes (7ème partie) : les fonctions 3D et 2D+M en version 1.5 / Anonyme in Géomatique expert, n° 83 (01/11/2011)
• PostGIS pour les néophytes (5ème partie) / Anonyme in Géomatique expert, n° 81 (01/07/2011)

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A new GIScience application for visualized natural resources management and decision support / Y. Yang in Transactions in GIS, vol 15 supplement s1 (July 2011)  

Public [article]  inTransactions in GIS > vol 15 supplement s1 (July 2011) . - pp 109 - 124 Titre : A new GIScience application for visualized natural resources management and decision support Type de document : Article/Communication Auteurs : Y. Yang, Auteur ; Y. Lin, Auteur Année de publication : 2011 Article en page(s) : pp 109 - 124 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG [Termes descripteurs IGN] consommation [Termes descripteurs IGN] eau souterraine [Termes descripteurs IGN] impact sur l'environnement [Termes descripteurs IGN] interface graphique [Termes descripteurs IGN] outil d'aide à la décision [Termes descripteurs IGN] requête spatiale [Termes descripteurs IGN] ressources en eau [Termes descripteurs IGN] risque naturel [Termes descripteurs IGN] WebSIG Résumé : (Auteur) This article presents two decision support plug-ins in free GIS software: ArcGIS Explorer Desktop. The ubiquitous WebGIS Analysis Toolkit for Extensive Resources (uWATER) focuses on providing GIS analysis functions: spatial and attribute queries in the public services tool for users with limited access to commercial GIS software. The interface of uWATER is general enough to support decision-making in numerous management issues in natural resources, economics and agriculture. The uWATER-Pumping Assessment (uWATER-PA) toolkit, on the other hand, is an extended package targeting the specific environmental issue of groundwater pumping impacts. The uWATER-PA package is an excellent alternative to evaluating complex groundwater pumping assessment issues before investing significant time, labor, and funds in monitoring and detailed scientific study. It incorporates simulation of the physics of groundwater flow and user interaction into GIS software. A graphical user interface makes both data entry and interpretation of results intuitive to non-technical individuals. Results are presented as colored drawdown maps and can be saved in GIS format for future dissemination. The impact of drawdown on existing wells can be characterized and mapped, through the use of uWATER's spatial query capabilities and the drawdown maps generated by uWATER-PA. Numéro de notice : A2011-253 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2011.01267.x date de publication en ligne : 09/06/2011 En ligne : https://doi.org/10.1111/j.1467-9671.2011.01267.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31031 [article]

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Query-aware location anonymization for road networks / C. Chow in Geoinformatica, vol 15 n° 3 (July 2011)  

Public [article]  inGeoinformatica > vol 15 n° 3 (July 2011) . - pp 571 - 607 Titre : Query-aware location anonymization for road networks Type de document : Article/Communication Auteurs : C. Chow, Auteur ; M. Mokbel, Auteur ; Jie Bao, Auteur ; X. Liu, Auteur Année de publication : 2011 Article en page(s) : pp 571 - 607 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes descripteurs IGN] espace euclidien [Termes descripteurs IGN] requête spatiale [Termes descripteurs IGN] réseau routier [Termes descripteurs IGN] service fondé sur la position Résumé : (Auteur) Recently, several techniques have been proposed to protect the user location privacy for location-based services in the Euclidean space. Applying these techniques directly to the road network environment would lead to privacy leakage and inefficient query processing. In this paper, we propose a new location anonymization algorithm that is designed specifically for the road network environment. Our algorithm relies on the commonly used concept of spatial cloaking, where a user location is cloaked into a set of connected road segments of a minimum total length L including at least K users. Our algorithm is “query-aware” as it takes into account the query execution cost at a database server and the query quality, i.e., the number of objects returned to users by the database server, during the location anonymization process. In particular, we develop a new cost function that balances between the query execution cost and the query quality. Then, we introduce two versions of our algorithm, namely, pure greedy and randomized greedy, that aim to minimize the developed cost function and satisfy the user specified privacy requirements. To accommodate intervals with a high workload, we introduce a shared execution paradigm that boosts the scalability of our location anonymization algorithm and the database server to support large numbers of queries received in a short time period. Extensive experimental results show that our algorithms are more efficient and scalable than the state-of-the-art technique, in terms of both query execution cost and query quality. The results also show that our algorithms have very strong resilience to two privacy attacks, namely, the replay attack and the center-of-cloaked-area attack. Numéro de notice : A2011-212 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-010-0117-0 date de publication en ligne : 06/11/2010 En ligne : https://doi.org/10.1007/s10707-010-0117-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30990 [article]

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The partial sequenced route query with traveling rules in road networks / H. Chen in Geoinformatica, vol 15 n° 3 (July 2011)  

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CartoMundi, collectio chartarum orbe terrae / Jean-Luc Arnaud in Géomatique expert, n° 80 (01/05/2011)

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Collaborative web-GIS design: a case study for road risk analysis and monitoring / Francesco Pirotti in Transactions in GIS, vol 15 n° 2 (April 2011)  

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PostGIS pour les néophytes (3ème partie) : Géométries, création de tables et opérateurs élémentaires / Anonyme in Géomatique expert, n° 79 (01/03/2011)

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Analyse spatiale de l'information géographique / R. Caloz (2011)

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Functional description of geoprocessing services as conjunctive datalog queries / D. Fitzner in Geoinformatica, vol 15 n° 1 (January 2011)  

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IRSJ : incremental refining spatial joins for interactive queries in GIS / W. Bae in Geoinformatica, vol 14 n° 4 (October 2010)  

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Exploiting geographic references of documents in a geographical information retrieval system using an ontology-based index / N. Brisaboa in Geoinformatica, vol 14 n° 3 (July 2010)  

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A knowledge infrastructure for intelligent query answering in Location-based Services / S Yu in Geoinformatica, vol 14 n° 3 (July 2010)  

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Ontologies and database management system technology for The National Map / N. Wiegand in Cartographica, vol 45 n° 2 (June 2010)  

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