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Analysing spatio-temporal autocorrelation with LISTA-Viz / F. Hardisty in International journal of geographical information science IJGIS, vol 24 n° 10 (october 2010)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 24 n° 10 (october 2010) . - pp 1515 - 1526 Titre : Analysing spatio-temporal autocorrelation with LISTA-Viz Type de document : Article/Communication Auteurs : F. Hardisty, Auteur ; Alexander Klippel, Auteur Année de publication : 2010 Article en page(s) : pp 1515 - 1526 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] analyse spatio-temporelle [Termes IGN] autocorrélation [Termes IGN] corrélation [Termes IGN] données spatiotemporelles [Termes IGN] méthode de Monte-Carlo Résumé : (Auteur) Many interesting analysis problems (e.g. disease surveillance) would become more tractable if their spatio-temporal structure was better understood. Specifically, it would be helpful to be able to identify autocorrelation in space and time simultaneously. Some of the most commonly used measures of spatial association are LISA statistics, such as the Local Moran's I or the Getis-Ord Gi*; however, these have not been applied to the spatio-temporal case (including many time steps) because of computational limitations. We have implemented a spatio-temporal version of the Local Moran's I and claimed two advances: first, we exploit the fact that there are a limited number of topological relationships present in the data to make Monte Carlo's estimation of probability densities computationally practical, and thereby bypass the 'curse of dimensionality'. We term this approach 'spatial memoization'. Second, we developed a tool (LISTA-Viz) for interacting with the spatio-temporal structure uncovered by the statistics that contains a novel coordination strategy. The potential usefulness of the method and the associated tool are illustrated by an analysis of the 2009 H1N1 pandemic, with the finding that there was a critical spatio-temporal 'inflection point' at which the pandemic changed its character in the United States. Numéro de notice : A2010-464 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658816.2010.511717 En ligne : https://doi.org/10.1080/13658816.2010.511717 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30657 [article]

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079-2010062	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Colour-enhanced star plot glyphs : can salient shape characteristics be overcome? / Alexander Klippel in Cartographica, vol 44 n° 3 (September 2009)  

Public [article]  inCartographica > vol 44 n° 3 (September 2009) . - pp 217 - 232 Titre : Colour-enhanced star plot glyphs : can salient shape characteristics be overcome? Type de document : Article/Communication Auteurs : Alexander Klippel, Auteur ; F. Hardisty, Auteur ; R. Li, Auteur ; C. Weaver, Auteur Année de publication : 2009 Article en page(s) : pp 217 - 232 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Rédaction cartographique [Termes IGN] analyse discriminante [Termes IGN] classification [Termes IGN] couleur (rédaction cartographique) [Termes IGN] lisibilité perceptive [Termes IGN] variable visuelle Résumé : (Auteur) This article reports two experiments addressing the question of how the shape characteristics of star plot glyphs influence classification tasks and whether additional graphic features such as colour can be used to counterbalance the effects of shape characteristics. In a previous study we found that salient shapes of star plot glyphs, such as "has one spike," influence the classification of the data represented by the glyphs. The shape differences in star plot glyphs are induced by assigning variables to rays in different ways. The first two experiments showed shape influences; we then conducted two follow-up studies to shed more light on the influence of shape. First, to address the question of how the classification of star plot glyphs would be affected if they were stripped of their meaning, participants were asked to group star plot glyphs as shapes. The second study colour-coded the rays of star plot glyphs to focus attention on differences in salient shapes; for example, the general shape characteristic "has one spike" cannot be applied so easily if each spike is a different colour. The results show that colour-enhancing star plot glyphs improves processing speed and reduces the influence of salient shape characteristics. Copyright University of Toronto Press Numéro de notice : A2009-411 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.3138/carto.44.3.217 Date de publication en ligne : 02/10/2009 En ligne : https://doi.org/10.3138/carto.44.3.217 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30042 [article]

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031-09031	RAB	Revue	Centre de documentation	En réserve L003	Disponible

GeoJabber: enabling geo-collaborative visual analysis / F. Hardisty in Cartography and Geographic Information Science, vol 36 n° 3 (July 2009)  

Public [article]  inCartography and Geographic Information Science > vol 36 n° 3 (July 2009) . - pp 267 - 280 Titre : GeoJabber: enabling geo-collaborative visual analysis Type de document : Article/Communication Auteurs : F. Hardisty, Auteur Année de publication : 2009 Article en page(s) : pp 267 - 280 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse spatiale [Termes IGN] diffusion de données [Termes IGN] GeoViz Toolkit [Termes IGN] logiciel de visualisation [Termes IGN] logiciel libre [Termes IGN] synergiciel [Termes IGN] visualisation de données [Vedettes matières IGN] Géovisualisation Résumé : (Auteur) The GeoJabber concept, protocol, and working prototype software introduced here enable same-time, different-place collaborative geovisualization. The key problem this work addresses is how to turn geovisual software states into persistent textual representations that can be shared between users. In the current implementation, GeoJabber leverages three key Open Source technologies: the GeoViz Toolkit, the Jabber protocol, and XStream. GeoJabber is the first project to support same-time different-place geovisualization tool state sharing. As part of this effort, this paper presents a typology of sharable geovisualization software states, rooted in the concepts of data, display, and category. Copyright CaGISociety Numéro de notice : A2009-270 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304009788988332 En ligne : https://doi.org/10.1559/152304009788988332 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29900 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-09031	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Star plots: how shape characteristics influence classification tasks / Alexander Klippel in Cartography and Geographic Information Science, vol 36 n° 2 (April 2009)  

Public [article]  inCartography and Geographic Information Science > vol 36 n° 2 (April 2009) . - pp 149 - 163 Titre : Star plots: how shape characteristics influence classification tasks Type de document : Article/Communication Auteurs : Alexander Klippel, Auteur ; F. Hardisty, Auteur ; C. Weaver, Auteur Année de publication : 2009 Article en page(s) : pp 149 - 163 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie thématique [Termes IGN] analyse multivariée [Termes IGN] classification [Termes IGN] sémiologie graphique [Termes IGN] symbole graphique Résumé : (Auteur) Our research addresses the question of how to design interfaces for spatial analysis such that they support cognitive processes. In this paper, we specifically target the question of map symbol design for the analysis of multivariate data, which is a common problem in cartography and related fields. We focus on star plots and the largely unaddressed question of how to assign variables to rays in a star plot and which consequences specific shapes haveas the result of data characteristics and the assignment of variables to rayson interpretation and classification. We conducted an experiment with two conditions that were designed to shed light on the question: Does the shape of a star plot influence the interpretation (meaning) of the data it represents in a classification task? While previous research on multivariate point symbols has addressed this question for Chernoff faces, for example, few connections have been made to the shape of a star plot and its potential influence on meaning. We found that certain salient shape characteristics induced by variations along the horizontal and vertical axis increase the classification speed. However, we also found that salient shapes, such as has one spike, introduce a perceptual similarity that overrides the assumed similarities in the meaning of the represented data. Copyright CaGISociety Numéro de notice : A2009-164 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304009788188808 En ligne : https://doi.org/10.1559/152304009788188808 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29794 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-09021	RAB	Revue	Centre de documentation	En réserve L003	Disponible