Centre de documentation
scientifique

Simulating spatial dynamics and processes in a retail gasoline market: An agent-based modeling approach / Alison J. Heppenstall in Transactions in GIS, vol 17 n° 5 (October 2013)  

Public [article]  inTransactions in GIS > vol 17 n° 5 (October 2013) . - pp 661 - 682 Titre : Simulating spatial dynamics and processes in a retail gasoline market: An agent-based modeling approach Type de document : Article/Communication Auteurs : Alison J. Heppenstall, Auteur ; Kirk Harland, Auteur ; Andrew N. Ross, Auteur ; Dan Olner, Auteur Année de publication : 2013 Article en page(s) : pp 661 - 682 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] agent (intelligence artificielle) [Termes IGN] analyse spatiale [Termes IGN] consommation [Termes IGN] coût [Termes IGN] dynamique spatiale [Termes IGN] économie de marché [Termes IGN] modélisation spatiale [Termes IGN] pétrole [Termes IGN] processus spatial [Termes IGN] vente Résumé : (Auteur) Simulating the dynamics and processes within a spatially influenced retail market, such as the retail gasoline market, is a highly challenging research area. Current approaches are limited through their inability to model the impact of supplier or consumer behavior over both time and space. Agent-based models (ABMs) provide an alternative approach that overcomes these problems. We demonstrate how knowledge of retail pricing is extended by using a ‘hybrid’ model approach: an agent model for retailers and a spatial interaction model for consumers. This allows the issue of spatial competition between individual retailers to be examined in a way only accessible to agent-based models, allowing each model retailer autonomous control over optimizing their price. The hybrid model is shown to be successful at recreating spatial pricing dynamics at a national scale, simulating the effects of a rise in crude oil prices as well as accurately predicting which retailers were most susceptible to closure over a 10-year period. Numéro de notice : A2013-576 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/tgis.12027 Date de publication en ligne : 23/04/2013 En ligne : https://doi.org/10.1111/tgis.12027 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32712 [article]

Spatial approaches to modeling dispersion of communicable diseases : A review / L. Bian in Transactions in GIS, vol 17 n° 1 (February 2013)  

Public [article]  inTransactions in GIS > vol 17 n° 1 (February 2013) . - pp 1 - 17 Titre : Spatial approaches to modeling dispersion of communicable diseases : A review Type de document : Article/Communication Auteurs : L. Bian, Auteur Année de publication : 2013 Article en page(s) : pp 1 - 17 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] analyse comparative [Termes IGN] diffusion spatiale [Termes IGN] données spatiotemporelles [Termes IGN] épidémie [Termes IGN] modèle de dispersion [Termes IGN] processus spatial [Termes IGN] processus temporel [Termes IGN] système d'information géographique Résumé : (Auteur) The dispersion of communicable diseases in a population is intrinsically spatial. In the last several decades, a range of spatial approaches has been devised to model epidemiological processes; and they differ significantly from each other. A review of spatially oriented epidemiological models is necessary to assess advances in spatial approaches to modeling disease dispersion and to help identify those most appropriate for specific research goals. The most notable difference in the design of these spatially oriented models is the scale and mobility of the modeling unit. Using two criteria, this review identifies six types of spatially oriented models. These include: (1) population-based wave models, (2) sub-population models, (3) individual-based cellular automata models, (4) mobile sub-population models, (5) individual-based spatially implicit models, and (6) individual-based mobile models. Each model type is evaluated in terms of its design principles, assumptions, and intended applications. For the evaluation of design, four aspects of design principles are discussed: the modeling unit, the interaction between the modeling units, the spatial process, and the temporal process utilized in a design. Insights gained from this review can be useful for devising much-needed spatially and temporally oriented strategies to forecast, prevent, and control communicable diseases. Numéro de notice : A2013-037 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01329.x Date de publication en ligne : 23/07/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01329.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32175 [article]

Plant species coexistence at local scale in temperate swamp forest: test of habitat heterogeneity hypothesis / Jan Douda in Oecologia, vol 169 n° 2 (June 2012)

Public [article]  inOecologia > vol 169 n° 2 (June 2012) . - pp 523 - 534 Titre : Plant species coexistence at local scale in temperate swamp forest: test of habitat heterogeneity hypothesis Type de document : Article/Communication Auteurs : Jan Douda, Auteur ; Jana Doudova-Kochankova, Auteur ; Karel Boublík, Auteur ; Alena Drasnarova, Auteur Année de publication : 2012 Article en page(s) : pp 523 - 534 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] forêt marécageuse [Termes IGN] habitat (nature) [Termes IGN] habitat forestier [Termes IGN] hétérogénéité environnementale [Termes IGN] niveau local [Termes IGN] phytosociologie [Termes IGN] processus spatial [Vedettes matières IGN] Ecologie forestière Résumé : (auteur) It has been suggested that a heterogeneous environment enhances species richness and allows for the coexistence of species. However, there is increasing evidence that environmental heterogeneity can have no effect or even a negative effect on plant species richness and plant coexistence at a local scale. We examined whether plant species richness increases with local heterogeneity in the water table depth, microtopography, pH and light availability in a swamp forest community at three local spatial scales (grain: 0.6, 1.2 and 11.4 m). We also used the variance partitioning approach to assess the relative contributions of niche-based and other spatial processes to species occurrence. We found that heterogeneity in microtopography and light availability positively correlated with species richness, in accordance with the habitat heterogeneity hypothesis. However, we recorded different heterogeneity– diversity relationships for particular functional species groups. An increase in the richness of bryophytes and woody plant species was generally related to habitat heterogeneity at all measured spatial scales, whereas a low impact on herbaceous species richness was recorded only at the 11.4 m scale. The distribution of herbaceous plants was primarily explained by other spatial processes, such as dispersal, in contrast to the occurrence of bryophytes, which was better explained by environmental factors. Our results suggest that both niche-based and other spatial processes are important determinants of the plant composition and species turnover at local spatial scales in swamp forests. Numéro de notice : A2012-137 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81640 [article]

Algorithms for constrained k-nearest neighbor queries over moving object trajectories / Yunjun Gao in Geoinformatica, vol 14 n° 2 (April 2010)  

Public [article]  inGeoinformatica > vol 14 n° 2 (April 2010) . - pp 241 - 276 Titre : Algorithms for constrained k-nearest neighbor queries over moving object trajectories Type de document : Article/Communication Auteurs : Yunjun Gao, Auteur ; B. Zheng, Auteur ; G. Chen, Auteur ; Qi Li, Auteur Année de publication : 2010 Article en page(s) : pp 241 - 276 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] arbre-R [Termes IGN] base de données d'objets mobiles [Termes IGN] base de données spatiotemporelles [Termes IGN] classification barycentrique [Termes IGN] objet mobile [Termes IGN] processus spatial [Termes IGN] programmation par contraintes [Termes IGN] requête spatiale Résumé : (Auteur) An important query for spatio-temporal databases is to find nearest trajectories of moving objects. Existing work on this topic focuses on the closest trajectories in the whole data space. In this paper, we introduce and solve constrained k-nearest neighbor (CkNN) queries and historical continuous CkNN (HCCkNN) queries on R-tree-like structures storing historical information about moving object trajectories. Given a trajectory set D, a query object (point or trajectory) q, a temporal extent T, and a constrained region CR, (i) a CkNN query over trajectories retrieves from D within T, the k (? 1) trajectories that lie closest to q and intersect (or are enclosed by) CR; and (ii) an HCCkNN query on trajectories retrieves the constrained k nearest neighbors (CkNNs) of q at any time instance of T. We propose a suite of algorithms for processing CkNN queries and HCCkNN queries respectively, with different properties and advantages. In particular, we thoroughly investigate two types of CkNN queries, i.e., CkNNP and CkNNT, which are defined with respect to stationary query points and moving query trajectories, respectively; and two types of HCCkNN queries, namely, HCCkNNP and HCCkNNT, which are continuous counterparts of CkNNP and CkNNT, respectively. Our methods utilize an existing data-partitioning index for trajectory data (i.e., TB-tree) to achieve low I/O and CPU cost. Extensive experiments with both real and synthetic datasets demonstrate the performance of the proposed algorithms in terms of efficiency and scalability. Copyright Springer Numéro de notice : A2010-067 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-009-0084-5 Date de publication en ligne : 28/04/2009 En ligne : https://doi.org/10.1007/s10707-009-0084-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30263 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-2010021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Spatial econometrics: methods and models / Luc Anselin (1988)

Public Titre : Spatial econometrics: methods and models Type de document : Monographie Auteurs : Luc Anselin, Auteur Editeur : Dordrecht : Kluwer Academic Publishers Année de publication : 1988 Importance : 284 p. Format : 16 x 24 cm ISBN/ISSN/EAN : 978-90-247-3735-2 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Statistiques [Termes IGN] analyse spatiale [Termes IGN] économétrie [Termes IGN] géostatistique [Termes IGN] inférence statistique [Termes IGN] méthode du maximum de vraisemblance (estimation) [Termes IGN] processus spatial [Termes IGN] processus stochastique [Termes IGN] statistique mathématique Index. décimale : 23.60 Statistiques et probabilités Résumé : (auteur) Spatial econometrics deals with spatial dependence and spatial heterogeneity, critical aspects of the data used by regional scientists. These characteristics may cause standard econometric techniques to become inappropriate. In this book, I combine several recent research results to construct a comprehensive approach to the incorporation of spatial effects in econometrics. My primary focus is to demonstrate how these spatial effects can be considered as special cases of general frameworks in standard econometrics, and to outline how they necessitate a separate set of methods and techniques, encompassed within the field of spatial econometrics. My viewpoint differs from that taken in the discussion of spatial autocorrelation in spatial statistics - e.g., most recently by Cliff and Ord (1981) and Upton and Fingleton (1985) - in that I am mostly concerned with the relevance of spatial effects on model specification, estimation and other inference, in what I caIl a model-driven approach, as opposed to a data-driven approach in spatial statistics. I attempt to combine a rigorous econometric perspective with a comprehensive treatment of methodological issues in spatial analysis. Note de contenu : Introduction 1 - Foundations for econometric analysis for spatial processes 2 - Estimation and hypothesis testing 3 - Model validation Conclusion Numéro de notice : 21542 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/MATHEMATIQUE Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90487

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
21542-01	23.60	Livre	Centre de documentation	Mathématiques	Disponible