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A graphical method for exploring spatiotemporal point distributions / Yukio Sadahiro in Cartography and Geographic Information Science, vol 29 n° 2 (April 2002)  

Public [article]  inCartography and Geographic Information Science > vol 29 n° 2 (April 2002) . - pp 67 - 84 Titre : A graphical method for exploring spatiotemporal point distributions Type de document : Article/Communication Auteurs : Yukio Sadahiro, Auteur Année de publication : 2002 Article en page(s) : pp 67 - 84 Langues : Anglais (eng) Descripteur : [Termes IGN] analyse de données [Termes IGN] analyse spatio-temporelle [Termes IGN] diagramme [Termes IGN] distribution spatiale [Termes IGN] données spatiotemporelles [Termes IGN] point [Termes IGN] représentation graphique [Vedettes matières IGN] Géovisualisation Résumé : (Auteur) A spatiotemporal point distribution is a set of points defined by the combination of a spatial region and a time period. It is used for representing a set of discrete events, such as traffic accidents, and a set of points that characterize line and polygon objects such as the turning points of insect movement. Analysis of a spatiotemporal point distribution is more difficult than an ordinary spatial point distribution because it has to be treated in a three or fourdimensional spatiotemporal region, where data visualization and analysis have not been fully explored. This paper proposes a new method for representing the spatiotemporal point distribution, which is useful for exploratory analysis. The method summarizes the information extracted from the point distribution, and thus helps us find important and interesting patterns in the distribution. It consists of two steps: conversion of a spatiotemporal point distribution into a surface, and graphic representation of the surface. Along with a theoretical description of the method, technical details including a computational algorithm are discussed. To test the validity of the method, an expansion of convenience stores in Tokyo, Japan, is analyzed. Numéro de notice : A2002-142 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304002782053332 En ligne : https://doi.org/10.1559/152304002782053332 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22057 [article]

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032-02021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Interactivity types in geographic visualization / J.W. Crampton in Cartography and Geographic Information Science, vol 29 n° 2 (April 2002)  

Public [article]  inCartography and Geographic Information Science > vol 29 n° 2 (April 2002) . - pp 85 - 98 Titre : Interactivity types in geographic visualization Type de document : Article/Communication Auteurs : J.W. Crampton, Auteur Année de publication : 2002 Article en page(s) : pp 85 - 98 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG [Termes IGN] carte interactive [Termes IGN] cartographie thématique [Termes IGN] interactivité [Termes IGN] représentation des données [Termes IGN] système d'information géographique [Termes IGN] visualisation Résumé : (Auteur) This paper introduces and discusses types of interactivity that can be used in digital mapping environments. The interactivity types are placed in the framework of geographic visualization (GVis) in order to extend the GVis emphasis on exploratory, interactive and private functions of spatial displays. After defining interactivity in general, four categories of interactivity are proposed: with (1) the Data; (2) the Data Representation; (3) the Temporal Dimension; and (4) Contextualizing Interaction. Three benefits of this typology are discussed. First, interactivity types can be combined to build an interactive environment. More powerful interactive mapping environments not only employ more interactivity types, but combine types from different categories. Second, the typology allows cartographers to compare and critique different mapping and GIS environments and gives cartography educators and students a mechanism for understanding the different types of interactivity, as well as a set of concepts for imagining and creating new interactive environments. Third, a typology of interactivity gives interface designers a mechanism with which to identify needs and measure interface effectiveness. In order to examine these issues in practice, two common interactive mapping environments are briefly examined to determine the interactivity types employed, and a measurable difference of interactive potential is obtained. Numéro de notice : A2002-143 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304002782053314 En ligne : https://doi.org/10.1559/152304002782053314 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22058 [article]

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032-02021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Artificial neural networks as a method of spatial interpolation for digital elevation models / D.A. Merwin in Cartography and Geographic Information Science, vol 29 n° 2 (April 2002)  

Public [article]  inCartography and Geographic Information Science > vol 29 n° 2 (April 2002) . - pp 99 - 110 Titre : Artificial neural networks as a method of spatial interpolation for digital elevation models Type de document : Article/Communication Auteurs : D.A. Merwin, Auteur ; R.G. Cromley, Auteur ; Daniel L. Civco, Auteur Année de publication : 2002 Article en page(s) : pp 99 - 110 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes IGN] interpolation inversement proportionnelle à la distance [Termes IGN] interpolation spatiale [Termes IGN] modèle numérique de surface [Termes IGN] réseau neuronal artificiel [Termes IGN] valeur efficace Résumé : (Auteur) This paper examines the performance of artificial neural networks (ANNs) as a method of spatial interpolation, when presented with irregular and regular samples of elevation data. The results of the ANN interpolation are compared with results obtained by kriging. Tests of spatial bias in the systematic errors contained in each of the neural network-derived DEMs were conducted using four attributes: slope, aspect, average direction and average distance from the nearest sampled value. Based on RMS and other evaluation measures, the accuracy of estimated DEMs from regular and irregular sample distributions using neural networks is lower than the accuracy level derived from kriging. The accuracy level of the ANN interpolators also decreases as the range of elevation values in DEMs increases. As reported in the literature, ANNs are approximate interpolators, and the pattern of under-prediction and over-prediction of elevation values in this study revealed that all estimated values fell within the range of sample elevations. Neural networks cannot predict values outside the range of elevation values contained in the sample, a property shared by other interpolators such as inverse weighted distance. Numéro de notice : A2002-144 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1559/152304002782053323 En ligne : https://doi.org/10.1559/152304002782053323 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22059 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-02021	RAB	Revue	Centre de documentation	En réserve L003	Disponible