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Utilizing the density of inventory samples to define a hybrid lattice for species distribution models: DISTRIB‐II for 135 eastern U.S. trees / Matthew P. Peters in Ecology and evolution, vol 9 n° 15 (August 2019)  

Public [article]  inEcology and evolution > vol 9 n° 15 (August 2019) . - pp 8876 - 8899 Titre : Utilizing the density of inventory samples to define a hybrid lattice for species distribution models: DISTRIB‐II for 135 eastern U.S. trees Type de document : Article/Communication Auteurs : Matthew P. Peters, Auteur ; Louis R. Iverson, Auteur ; Anantha M. Prasad, Auteur ; Stephen N. Matthews, Auteur Année de publication : 2019 Article en page(s) : pp 8876 - 8899 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] arbre (flore) [Termes IGN] densité [Termes IGN] distribution spatiale [Termes IGN] données météorologiques [Termes IGN] inventaire forestier étranger (données) [Termes IGN] modèle mathématique [Termes IGN] placette d'échantillonnage [Vedettes matières IGN] Inventaire forestier Résumé : (auteur) Species distribution models (SDMs) provide useful information about potential presence or absence, and environmental conditions suitable for a species; and high‐resolution models across large extents are desirable. A primary feature of SDMs is the underlying spatial resolution, which can be chosen for many reasons, though we propose that a hybrid lattice, in which grid cell sizes vary with the density of forest inventory plots, provides benefits over uniform grids. We examine how the spatial grain size affected overall model performance for the Random Forest‐based SDM, DISTRIB, which was updated with recent forest inventories, climate, and soil data, and used a hybrid lattice derived from inventory densities. Modeled habitat suitability was compared between a uniform grid of 10 × 10 and a hybrid lattice of 10 × 10 and 20 × 20 km grids to assess potential improvements. The resulting DISTRIB‐II models for 125 eastern U.S. tree species provide information on individual habitat suitability that can be mapped and statistically analyzed to understand current and potential changes. Model performance metrics were comparable among the hybrid lattice and 10‐km grids; however, the hybrid lattice models generally had higher overall model reliability scores and were likely more representative of the inventory data. Our efforts to update DISTRIB models with current information aims to produce a more representative depiction of recent conditions by accounting for the spatial density of forest inventory data and using the latest climate data. Additionally, we developed an approach that leverages a hybrid lattice to maximize the spatial information within the models and recommend that similar modeling efforts be used to evaluate the spatial density of response and predictor data and derive a modeling grid that best represents the environment. Numéro de notice : A2019-374 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1002/ece3.5445 Date de publication en ligne : 17/07/2019 En ligne : https://doi.org/10.1002/ece3.5445 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93415 [article]

Modelling distribution of archaeological settlement evidence based on heterogeneous spatial and temporal data / Peter Demján in Journal of archaeological science, vol 69 (May 2016)  

Public [article]  inJournal of archaeological science > vol 69 (May 2016) . - pp 100 - 109 Titre : Modelling distribution of archaeological settlement evidence based on heterogeneous spatial and temporal data Type de document : Article/Communication Auteurs : Peter Demján, Auteur ; Dagmar Dreslerová, Auteur Année de publication : 2016 Article en page(s) : pp 100 - 109 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] Bohème [Termes IGN] densité [Termes IGN] données spatiotemporelles [Termes IGN] préhistoire [Termes IGN] République Tchèque [Termes IGN] site archéologique Résumé : (auteur) We analyse variations in prehistoric agricultural settlement behaviour both in space and time to detect main turning points and shifts in settlement patterns in Bohemia, western Czech Republic. We propose a theoretical framework to address our research question and a new evidence density estimation (EDE) method combining and extending existing approaches to produce probabilistic maps and temporal frequency distribution (TFD) curves. This method takes into account heterogeneous spatial and temporal accuracy of archaeological data, and it models settlement structure where respective sites have a specific area and a given interval of duration. We determined minimal sampling densities of archaeological data enabling the method to predict prehistoric settlement at a statistically significant level. The EDE method is universally applicable for all datasets with sampling densities of more than 0.05 archaeological actions per km2 for chrono-typologically dated evidence and 0.035 actions per km2 for radiocarbon or similar dates. The results show that changes in spatial extent, density and clustering of settlement activities occur repeatedly throughout the whole agricultural prehistory and shed new light on settlement behaviour of past populations. Numéro de notice : A2016--144 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1016/j.jas.2016.04.003 En ligne : https://doi.org/10.1016/j.jas.2016.04.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85893 [article]

Adaptive generation of variable-scale network maps for small displays based on line density distribution / Zhilin Li in Geoinformatica, vol 19 n° 2 (April - June 2015)  

Public [article]  inGeoinformatica > vol 19 n° 2 (April - June 2015) . - pp 277 - 295 Titre : Adaptive generation of variable-scale network maps for small displays based on line density distribution Type de document : Article/Communication Auteurs : Zhilin Li, Auteur ; Peng Ti, Auteur Année de publication : 2015 Article en page(s) : pp 277 - 295 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] analyse de données [Termes IGN] carte thématique [Termes IGN] densité [Termes IGN] échelle des données [Termes IGN] échelle variable [Termes IGN] généralisation cartographique automatisée [Termes IGN] lisibilité perceptive [Termes IGN] petit écran Résumé : (auteur) This paper presents an integrated strategy for adaptive generation of variable-scale network maps for different small displays. It is based on the line density distribution and comprised of three steps, i.e. (a) to estimate the line density by a grid-based method, (b) to adaptively generate variable-scale maps based on density distribution for given display sizes and (c) to improve the map readability by map generalization. The proposed strategy has been tested by using two real-life network datasets, with a statistical analysis and a perceptual evaluation. Experimental results show that this strategy is able to better exploit the limited map space so as to significantly improve map clarity and readability and at the same time to preserve map recognition ability compared to its original shape. Numéro de notice : A2015-489 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-014-0212-8 Date de publication en ligne : 03/06/2014 En ligne : https://doi.org/10.1007/s10707-014-0212-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77282 [article]

Stacked space-time densities: a geovisualisation approach to explore dynamics of space use over time / Urška Demšar in Geoinformatica, vol 19 n° 1 (January - March 2015)  

Public [article]  inGeoinformatica > vol 19 n° 1 (January - March 2015) . - pp 85 - 115 Titre : Stacked space-time densities: a geovisualisation approach to explore dynamics of space use over time Type de document : Article/Communication Auteurs : Urška Demšar, Auteur ; Kevin Buchin, Auteur ; E. Emiel Van Loon, Auteur ; Judy Shamoun-Baranes, Auteur Année de publication : 2015 Article en page(s) : pp 85 - 115 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] agrégation spatiale [Termes IGN] agrégation temporelle [Termes IGN] analyse spatio-temporelle [Termes IGN] Aves [Termes IGN] cube espace-temps [Termes IGN] densité [Termes IGN] distance de propagation [Termes IGN] données spatiotemporelles [Termes IGN] estimation par noyau [Termes IGN] migration animale [Termes IGN] positionnement cinématique [Vedettes matières IGN] Géovisualisation Résumé : (auteur) Recent developments and ubiquitous use of global positioning devices have revolutionised movement ecology. Scientists are able to collect increasingly larger movement datasets at increasingly smaller spatial and temporal resolutions. These data consist of trajectories in space and time, represented as time series of measured locations for each tagged animal. Such data are analysed and visualised using methods for estimation of home range or utilisation distribution, which are often based on 2D kernel density in geographic space. These methods have been developed for much sparser and smaller datasets obtained through very high frequency (VHF) radio telemetry. They focus on the spatial distribution of measurement locations and ignore time and sequentiality of measurements. We present an alternative geovisualisation method for spatio-temporal aggregation of trajectories of tagged animals: stacked space-time densities. The method was developed to visually portray temporal changes in animal use of space using a volumetric display in a space-time cube. We describe the algorithm for calculation of stacked densities using four different decay functions, normally used in space use studies: linear decay, bisquare decay, Gaussian decay and Brownian decay. We present a case study, where we visualise trajectories of lesser black backed gulls, collected over 30 days. We demonstrate how the method can be used to evaluate temporal site fidelity of each bird through identification of two different temporal movement patterns in the stacked density volume: spatio-temporal hot spots and spatial-only hot spots. Numéro de notice : A2015-486 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-014-0207-5 Date de publication en ligne : 03/04/2014 En ligne : https://doi.org/10.1007/s10707-014-0207-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77249 [article]

Geospatial analysis of urban landscape patterns in three major cities of Southeast Asia / Ronald C. Estoque in Tsukuba geoenvironmental sciences, vol 10 (december 2014)    

Public [article]  inTsukuba geoenvironmental sciences > vol 10 (december 2014) . - pp 3 - 10 Titre : Geospatial analysis of urban landscape patterns in three major cities of Southeast Asia Type de document : Article/Communication Auteurs : Ronald C. Estoque, Auteur ; Yuji Murayama, Auteur ; Courage Kamusoko, Auteur ; Akio Yamashita, Auteur Année de publication : 2014 Article en page(s) : pp 3 - 10 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse comparative [Termes IGN] Bangkok (Thaïlande) [Termes IGN] connexité (topologie) [Termes IGN] densité [Termes IGN] image Landsat [Termes IGN] Jakarta (Indonésie) [Termes IGN] Manille (Philippines) [Termes IGN] paysage urbain [Termes IGN] plan de déplacement urbain [Termes IGN] urbanisation [Termes IGN] utilisation du sol Résumé : (auteur) Using a geospatial approach that integrates gradient analysis and landscape metrics, this study examines and compares the urban landscape patterns of three major cities of Southeast Asia, namely Bangkok, Jakarta, and Manila. Landsat-8 imageries for 2013 and 2014 were used to classify the urban land-use/cover of the three cities. Furthermore, various class-level landscape metrics were computed to facilitate spatial analysis. The results reveal that the proportional extent or density and physical connectedness of built-up lands in the three cities are inversely related to the gradient of the distance from the city center. In contrast, the fragmentation of built-up lands is directly related to the gradient of the distance from the city center. In the comparison of the three cities, the density of the urban development of Manila is relatively higher than that of Bangkok, but more especially that of Jakarta. The urban landscape of Jakarta is relatively more fragmented or dispersed than that of Bangkok, but more especially that of Manila. In terms of physical connectedness, Manila’s urban landscape is relatively more aggregated than that of Bangkok, but more especially that of Jakarta. The study results show that the gradient analysis and landscape metrics integrated approach can be used to examine and compare the spatial patterns of various complex urban landscapes. Numéro de notice : 15895 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans En ligne : http://hdl.handle.net/2241/00123143 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79051 [article]

Documents numériques

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Crime analysis through spatial areal aggregated density patterns / P. Phillips in Geoinformatica, vol 15 n° 1 (January 2011)  

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Space-time density of trajectories : exploring spatio-temporal patterns in movement data / Urška Demšar in International journal of geographical information science IJGIS, vol 24 n° 10 (october 2010)  

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Selective omission of road features based on mesh density for automatic map generalization / J. Chen in International journal of geographical information science IJGIS, vol 23 n° 7-8 (july 2009)  

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Mapping tropical forest structure in south-eastern Madagascar using remote sensing and artificial neural networks / J.C. Ingram in Remote sensing of environment, vol 94 n° 4 (28/02/2005)  

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A minimum energy condition for the inverse gravimetric problem / Olivier Jamet (2005)  

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Zur Parametrisierung radialsymmetrischer Dichtemodelle für die Erde / H. Wziontek (2005)

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The discrete dynamics of small-scale spatial events: agent-based models of mobility in carnivals and street parades / Michael Batty in International journal of geographical information science IJGIS, vol 17 n° 7 (october 2003)  

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Figure de la Terre / F. Chambat (1996)

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Méthodes d'estimations de surfaces à partir d'une image numérique / J. Couronne (1988)

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Density distributions for the equipotential ellipsoid / Helmut Moritz (1968)

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