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Analytical estimation of map readability / Lars Harrie in ISPRS International journal of geo-information, vol 4 n°2 (June 2015)  

Public [article]  inISPRS International journal of geo-information > vol 4 n°2 (June 2015) . - pp 418 - 446 Titre : Analytical estimation of map readability Type de document : Article/Communication Auteurs : Lars Harrie, Auteur ; Hanna Stigmar, Auteur ; Milan Djordjevic, Auteur Année de publication : 2015 Article en page(s) : pp 418 - 446 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] apprentissage dirigé [Termes descripteurs IGN] distribution spatiale [Termes descripteurs IGN] généralisation cartographique automatisée [Termes descripteurs IGN] lisibilité perceptive [Termes descripteurs IGN] régression multiple [Termes descripteurs IGN] séparateur à vaste marge [Termes descripteurs IGN] seuillage [Termes descripteurs IGN] test de performance [Termes descripteurs IGN] utilisateur [Vedettes matières IGN] Cartologie Résumé : (auteur) Readability is a major issue with all maps. In this study, we evaluated whether we can predict map readability using analytical measures, both single measures and composites of measures. A user test was conducted regarding the perceived readability of a number of test map samples. Evaluations were then performed to determine how well single measures and composites of measures could describe the map readability. The evaluation of single measures showed that the amount of information was most important, followed by the spatial distribution of information. The measures of object complexity and graphical resolution were not useful for explaining the map readability of our test data. The evaluations of composites of measures included three methods: threshold evaluation, multiple linear regression and support vector machine. We found that the use of composites of measures was better for describing map readability than single measures, but we could not identify any major differences in the results of the three composite methods. The results of this study can be used to recommend readability measures for triggering and controlling the map generalization process of online maps. Numéro de notice : A2015-701 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://www.mdpi.com/2220-9964/4/2/418 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78343 [article]

A structural-lexical measure of semantic similarity for geo-knowledge graphs / Andrea Ballatore in ISPRS International journal of geo-information, vol 4 n°2 (June 2015)  

Public [article]  inISPRS International journal of geo-information > vol 4 n°2 (June 2015) . - pp 471 - 492 Titre : A structural-lexical measure of semantic similarity for geo-knowledge graphs Type de document : Article/Communication Auteurs : Andrea Ballatore, Auteur ; Michela Bertolotto, Auteur ; David C. Wilson, Auteur Année de publication : 2015 Article en page(s) : pp 471 - 492 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes descripteurs IGN] graphe [Termes descripteurs IGN] noeud [Termes descripteurs IGN] ontologie [Termes descripteurs IGN] OpenStreetMap [Termes descripteurs IGN] similitude sémantique [Termes descripteurs IGN] web sémantique Résumé : (auteur) Graphs have become ubiquitous structures to encode geographic knowledge online. The Semantic Web’s linked open data, folksonomies, wiki websites and open gazetteers can be seen as geo-knowledge graphs, that is labeled graphs whose vertices represent geographic concepts and whose edges encode the relations between concepts. To compute the semantic similarity of concepts in such structures, this article defines the network-lexical similarity measure (NLS). This measure estimates similarity by combining two complementary sources of information: the network similarity of vertices and the semantic similarity of the lexical definitions. NLS is evaluated on the OpenStreetMap Semantic Network, a crowdsourced geo-knowledge graph that describes geographic concepts. The hybrid approach outperforms both network and lexical measures, obtaining very strong correlation with the similarity judgments of human subjects. Numéro de notice : A2015-707 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://www.mdpi.com/2220-9964/4/2/471 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78344 [article]

Characterizing the heterogeneity of the OpenStreetMap data and community / Ding Ma in ISPRS International journal of geo-information, vol 4 n°2 (June 2015)  

Public [article]  inISPRS International journal of geo-information > vol 4 n°2 (June 2015) . - pp 535 - 550 Titre : Characterizing the heterogeneity of the OpenStreetMap data and community Type de document : Article/Communication Auteurs : Ding Ma, Auteur ; Mats Sandberg, Auteur ; Bin Jiang, Auteur Année de publication : 2015 Article en page(s) : pp 535 - 550 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes descripteurs IGN] analyse de groupement [Termes descripteurs IGN] données localisées des bénévoles [Termes descripteurs IGN] données massives [Termes descripteurs IGN] OpenStreetMap Résumé : (auteur) OpenStreetMap (OSM) constitutes an unprecedented, free, geographical information source contributed by millions of individuals, resulting in a database of great volume and heterogeneity. In this study, we characterize the heterogeneity of the entire OSM database and historical archive in the context of big data. We consider all users, geographic elements and user contributions from an eight-year data archive, at a size of 692 GB. We rely on some nonlinear methods such as power law statistics and head/tail breaks to uncover and illustrate the underlying scaling properties. All three aspects (users, elements, and contributions) demonstrate striking power laws or heavy-tailed distributions. The heavy-tailed distributions imply that there are far more small elements than large ones, far more inactive users than active ones, and far more lightly edited elements than heavy-edited ones. Furthermore, about 500 users in the core group of the OSM are highly networked in terms of collaboration. Numéro de notice : A2015-708 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://www.mdpi.com/2220-9964/4/2/535 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78345 [article]

The spatiotemporal dynamics of forest–heathland communities over 60 years in Fontainebleau, France / Samira Mobaied in ISPRS International journal of geo-information, vol 4 n°2 (June 2015)  

Public [article]  inISPRS International journal of geo-information > vol 4 n°2 (June 2015) . - pp 957 - 973 Titre : The spatiotemporal dynamics of forest–heathland communities over 60 years in Fontainebleau, France Type de document : Article/Communication Auteurs : Samira Mobaied, Auteur ; Nathalie Machon, Auteur ; Arnault Lalanne, Auteur ; Bernard Riera, Auteur Année de publication : 2015 Article en page(s) : pp 957 - 973 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes descripteurs IGN] aire protégée [Termes descripteurs IGN] analyse spatio-temporelle [Termes descripteurs IGN] carte de la végétation [Termes descripteurs IGN] couvert végétal [Termes descripteurs IGN] Fontainebleau, forêt de [Termes descripteurs IGN] forêt tempérée [Termes descripteurs IGN] habitat forestier [Termes descripteurs IGN] lande [Termes descripteurs IGN] photographie aérienne [Termes descripteurs IGN] protection de la biodiversité [Termes descripteurs IGN] sol [Termes descripteurs IGN] vingtième siècle Résumé : (auteur) According to the EU Habitats Directive, heathlands are “natural habitats of community interest”. Heathland management aims at conserving these habitats threatened by various changes, including successional processes leading to forest vegetation. We investigate the dynamics of woody species to the detriment of heathland over a period of 60 years in the Fontainebleau forest and we examine the effects of soil types, soil depth and topography parameters on heathland stability. We assess changes in forest cover between 1946 and 2003 by comparing vegetation maps derived from aerial photographs coupled to GIS analyses. The results show the loss of more than 75% of heathland during 1946–2003 due to tree colonisation of abandoned heathland. We detected differences in the dynamics of colonisation between coniferous and deciduous trees. The colonisation of heathland by coniferous species was faster over the last 20 years of our study period. Tree encroachment was faster in north-facing areas and in areas of acidic luvisols. While this dynamic was very slow in acid sandstone soils, heathland stability was more important in shallow soils on flat and south facing areas. Our study has the potential to assist land managers in selecting those heathland areas that will be easier to conserve and/or to restore by focusing on areas and spatial conditions that prevent forest colonisation and hence favour the long-term stability of heathland. Numéro de notice : A2015-709 Thématique : FORET/GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://www.mdpi.com/2220-9964/4/2/957 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78346 [article]