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Bayesian belief networks as a versatile method for assessing uncertainty in land-change modeling / Carsten Krüger in International journal of geographical information science IJGIS, vol 29 n° 1 (January 2015)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 29 n° 1 (January 2015) . - pp 111 - 131 Titre : Bayesian belief networks as a versatile method for assessing uncertainty in land-change modeling Type de document : Article/Communication Auteurs : Carsten Krüger, Auteur ; Tobia Lakes, Auteur Année de publication : 2015 Article en page(s) : pp 111 - 131 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] aide à la décision [Termes IGN] Amazonie [Termes IGN] Brésil [Termes IGN] changement d'occupation du sol [Termes IGN] changement d'utilisation du sol [Termes IGN] déboisement [Termes IGN] incertitude des données [Termes IGN] modèle conceptuel de données spatio-temporelles [Termes IGN] réseau bayesien [Termes IGN] théorie de Dempster-Shafer Résumé : (auteur) Land-use and land-cover change modeling helps us to understand the driving factors and impacts of human-induced land changes better, and depict likely future development paths. Uncertainty associated with various steps in the modeling process substantially influences the reliability of the results, but until now it has only rarely been addressed. In this study, we explore uncertainty in land-change modeling using a probabilistic approach based on Bayesian belief networks. We apply this approach to a case study of deforestation in the Brazilian Amazon and identify three modeling steps as sources of uncertainty: model structure, variable selection, and data preprocessing. For these three steps, we quantify the uncertainty and the respective impact on the outcome accuracy. The results indicate remarkable uncertainties in each of the steps. We demonstrate that a higher uncertainty in the land-change modeling process does not necessarily lead to a lower accuracy of the modeling outcome. Moreover, we show that the different uncertainty sources only slightly influence the ratio between quantity disagreement and allocation disagreement for the modeling outcome. We conclude that uncertainty is inherent in land-change modeling, and that future studies should address this uncertainty more explicitly to improve the robustness of modeling outcomes for science and decision-making. Numéro de notice : A2015-532 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2014.949265 En ligne : http://www.tandfonline.com/doi/full/10.1080/13658816.2014.949265 Format de la ressource électronique : URL bulletin Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77763 [article]

Spatial chromatic model in high-dimensional spaces and the uniqueness of chromatic code: a new perspective of geographic entity–space relationship / Weining Zhu in International journal of geographical information science IJGIS, vol 29 n° 1 (January 2015)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 29 n° 1 (January 2015) . - pp 28 - 45 Titre : Spatial chromatic model in high-dimensional spaces and the uniqueness of chromatic code: a new perspective of geographic entity–space relationship Type de document : Article/Communication Auteurs : Weining Zhu, Auteur Année de publication : 2015 Article en page(s) : pp 28 - 45 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG [Termes IGN] espace objet [Termes IGN] hétérogénéité spatiale [Termes IGN] modèle entité-association [Termes IGN] mosaïquage d'images [Termes IGN] tessellation Résumé : (Auteur) The abstraction, representation, and computation of entity–space relationship are keystones of geographic information science (GIS). The newly proposed spatial chromatic tessellation (SCT) provides a novel model to explore this relationship. SCT has demonstrated a variety of potential applications in GIS, such as reasoning spatial topology, point pattern analysis, and Voronoi diagrams. This study aims to theoretically investigate SCT by focusing on two aspects: (1) extending SCT to higher dimensional spaces. Results show that cells missing in lower dimensional spaces are hidden in higher dimensional spaces; (2) exploring the uniqueness of chromatic codes, particularly the chromatic codes of 2-cell and 3-cell clusters: their codes are proved to be unique. In a mathematical perspective, the observed phenomena from the above two aspects bring some new thoughts into the first law of geography and spatial heterogeneity. Based on these new understandings of entity–space relationship, SCT is replaced by spatial chromatic model (SCM) in which spaces are created by entities themselves rather than by partitioning the space preexisted. This makes a change from an absolute geographic space to a relative geographic space. Numéro de notice : A2015-574 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2014.931586 En ligne : http://www.tandfonline.com/doi/full/10.1080/13658816.2014.931586 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77836 [article]

A novel approach for generating routable road maps from vehicle GPS traces / Jing Wang in International journal of geographical information science IJGIS, vol 29 n° 1 (January 2015)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 29 n° 1 (January 2015) . - pp 69 - 91 Titre : A novel approach for generating routable road maps from vehicle GPS traces Type de document : Article/Communication Auteurs : Jing Wang, Auteur ; Xiaoping Rui, Auteur ; Xianfeng Song, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 69 - 91 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] données GPS [Termes IGN] PostGIS [Termes IGN] PostgreSQL [Termes IGN] Python (langage de programmation) [Termes IGN] récupération de données [Termes IGN] réseau routier [Termes IGN] trafic routier Résumé : (Auteur) Public vehicles and personal navigation assistants have become increasingly equipped with single-frequency global positioning system (GPS) receivers or loggers. These commonly used terminals offer an inexpensive way for acquiring large volumes of GPS traces, which contain information pertaining to road position and traffic rules. Using this new type of spatial data resource, we propose a novel approach for generating high-quality routable road maps. In this approach, a simplified road network graph model uses circular boundaries to separate all GPS traces into road intersections and road segments and builds road networks that maintain their identical geometric topologies through the entry/exit points at the original boundaries. One difficulty inherent to this type of approach is how to best determine the appropriate spatial coverage for road intersections. Conflict points among GPS traces that have large intersection angles usually occur within the physical areas of road intersections, particularly those involving left turns. Therefore, we determined a proper circle boundary for individual road intersections by conducting a spatial analysis of such feature points. This approach was implemented using Python and PostgreSQL/PostGIS and was tested in Huaibei City, China. Based on a comparison with human-interpreted results, the automatically generated routable road map was demonstrated to be of high quality and displayed detailed road networks with turning at various at-grade intersections, interchanges and U-turns. Numéro de notice : A2015-575 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2014.944527 En ligne : http://www.tandfonline.com/doi/full/10.1080/13658816.2014.944527 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77837 [article]

The fractal nature of maps and mapping / Bin Jiang in International journal of geographical information science IJGIS, vol 29 n° 1 (January 2015)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 29 n° 1 (January 2015) . - pp 159 - 174 Titre : The fractal nature of maps and mapping Type de document : Article/Communication Auteurs : Bin Jiang, Auteur Année de publication : 2015 Article en page(s) : pp 159 - 174 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] cartographie statistique [Termes IGN] échelle cartographique [Termes IGN] généralisation cartographique automatisée [Termes IGN] objet fractal [Vedettes matières IGN] Cartologie Résumé : (Auteur) A fractal can be simply understood as a set or pattern in which there are far more small things than large ones, for example, far more small geographic features than large ones on the earth surface, or far more large-scale maps than small-scale maps for a geographic region. This article attempts to argue and provide evidence for the fractal nature of maps and mapping. It is the underlying fractal structure of geographic features, either natural or man-made, that make reality mappable, large-scale maps generalizable, and cities imageable. The fractal nature is also what underlies the beauty of maps. After introducing some key fractal concepts such as recursion, self-similarity, scaling ratio, and scaling exponent, this article demonstrates that fractal thought is rooted in long-standing map-making practices such as series maps subdivision, visual hierarchy, and Töpfer’s radical law. Drawing on previous studies on head/tail breaks, mapping can be considered a head/tail breaks process; that is to divide things around an average, according to their geometric, topological and/or semantic properties, into the head (for those above the average) and the tail (for those below the average), and recursively continue the dividing process for the head for map generalization, statistical mapping, and cognitive mapping. Given the fractal nature of maps and mapping, cartography should be considered a perfect combination of science and art, and scaling must be formulated as a law of cartography or that of geography in general. Numéro de notice : A2015-576 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2014.953165 En ligne : http://www.tandfonline.com/doi/full/10.1080/13658816.2014.953165 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77838 [article]