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Study on offshore seabed sediment classification based on particle size parameters using XGBoost algorithm / Fengfan Wang in Computers & geosciences, vol 149 (April 2021)  

Public [article]  inComputers & geosciences > vol 149 (April 2021) . - n° 104713 Titre : Study on offshore seabed sediment classification based on particle size parameters using XGBoost algorithm Type de document : Article/Communication Auteurs : Fengfan Wang, Auteur ; Jia Yu, Auteur ; Zhijie Liu, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 104713 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes descripteurs IGN] analyse spatiale [Termes descripteurs IGN] calcul matriciel [Termes descripteurs IGN] Chine [Termes descripteurs IGN] classification par forêts aléatoires [Termes descripteurs IGN] classification par séparateurs à vaste marge [Termes descripteurs IGN] diagramme [Termes descripteurs IGN] échantillon [Termes descripteurs IGN] Extreme Gradient Machine [Termes descripteurs IGN] fond marin [Termes descripteurs IGN] gravier [Termes descripteurs IGN] image à haute résolution [Termes descripteurs IGN] sédiment [Termes descripteurs IGN] texture Résumé : (auteur) Folk's textual classification scheme which is widely used for sediment study operates with the proportions of gravel, sand, silt and clay fractions conventionally. However, dealing with data from different sources usually needs to face missing values that may make the classification difficult. To solve this problem and discover other methods of analyzing the scheme, with samples of offshore seabed sediment, a two-stage model was established to predict a sample's class using the XGBoost algorithm as well as the grain size parameters as input features. The final model was evaluated with quantitative performance measures of recall, precision and F1 score, and by comparing sediment texture maps using the predicted and the actual data. The results show that the model performs well on extraction of sediment samples without gravel fraction, and prediction of classes that have independent characteristics of grain size parameters or samples not near the boundaries of classes in the ternary diagram. The predicted sediment texture is close to the actual and could be reliable due to errors with little impact on further applications. It is demonstrated that the model could be an auxiliary or alternative approach to offshore sediment texture mapping, as well as supplementary to the analysis of sedimentary environment. Numéro de notice : A2021-289 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1016/j.cageo.2021.104713 date de publication en ligne : 12/02/2021 En ligne : https://doi.org/10.1016/j.cageo.2021.104713 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97400 [article]

Group diagrams for representing trajectories / Maike Buchin in International journal of geographical information science IJGIS, vol 34 n° 12 (December 2020)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 34 n° 12 (December 2020) . - pp 2401 - 2433 Titre : Group diagrams for representing trajectories Type de document : Article/Communication Auteurs : Maike Buchin, Auteur ; Bernhard Kilgus, Auteur ; Andrea Kölzsch, Auteur Année de publication : 2020 Article en page(s) : pp 2401 - 2433 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes descripteurs IGN] analyse de groupement [Termes descripteurs IGN] analyse spatio-temporelle [Termes descripteurs IGN] approximation [Termes descripteurs IGN] diagramme [Termes descripteurs IGN] distance de Fréchet [Termes descripteurs IGN] données GPS [Termes descripteurs IGN] géomètrie algorithmique [Termes descripteurs IGN] itinéraire [Termes descripteurs IGN] migration animale [Termes descripteurs IGN] mouvement [Termes descripteurs IGN] objet mobile [Termes descripteurs IGN] trajectoire Résumé : (auteur) Given the trajectories of one or several moving groups, we propose a new framework, the group diagram (GD) for representing these. Specifically, we seek a minimal GD as a concise representation of the groups maintaining the spatio-temporal structure of the groups’ movement. A GD is specified by three input values, namely a distance threshold, a similarity measure and a minimality criterion. For several variants of the GD, we give a comprehensive analysis of their computational complexity and present efficient approximation algorithms for their computation. Furthermore, we experimentally evaluate our algorithms on GPS data of migrating geese. Applying the proposed methods on these data sets reveals how the GD concisely represents the movement of the groups. This representation can be used for further analysis and for the formulation of new hypotheses for further ecological research, such as differences in movement patterns of groups on different surfaces or the shift of migration routes over several years. We use different similarity measures to summarize the migration routes of (i) a goose family for one migration period and to summarize (ii) the migration routes of one individual for several migration periods or (iii) the migration routes of several independent individuals for one migration period. Numéro de notice : A2020-690 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2019.1684498 date de publication en ligne : 25/11/2019 En ligne : https://doi.org/10.1080/13658816.2019.1684498 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96227 [article]

Micro diagrams: visualization of categorical point data from location-based social media / Mathias Gröbe in Cartography and Geographic Information Science, Vol 47 n° 4 (July 2020)  

Public [article]  inCartography and Geographic Information Science > Vol 47 n° 4 (July 2020) . - pp 305-320 Titre : Micro diagrams: visualization of categorical point data from location-based social media Type de document : Article/Communication Auteurs : Mathias Gröbe, Auteur ; Dirk Burghardt, Auteur Année de publication : 2020 Article en page(s) : pp 305-320 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] analyse spatiale [Termes descripteurs IGN] diagramme [Termes descripteurs IGN] données localisées des bénévoles [Termes descripteurs IGN] réseau social [Vedettes matières IGN] Géovisualisation Résumé : (Auteur) Location-based social media data from different platforms such as Twitter and Flickr increasingly serve with their point-geocoded content as data sources for a variety of applications. The standard visualization method uses a derivation of point maps, which works well with a limited amount of data, but it suffers from weaknesses related to cluttering and overlapping, especially for sets of categories. We developed a new visualization method for categorical point data, called “Micro Diagrams”, which uses small diagrams to show the percentages of categories and the spatial distribution. The processing steps to derive the micro diagrams start with aggregating the points in a regular grid structure, which is followed by the selection of the diagram type that represents the numerical proportions and the application of a size scaling function to show the amounts of data. Various parameterization options are discussed and the influence of the color selection is analyzed. Finally, a case study combined with a user test presents the strengths and limits of the micro diagram method. Numéro de notice : A2020-189 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/15230406.2020.1733438 date de publication en ligne : 10/03/2020 En ligne : https://doi.org/10.1080/15230406.2020.1733438 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95154 [article]

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The impact of map type on the level of student map skills / Lenka Havelková in Cartographica, vol 53 n° 3 (Fall 2018)  

Public [article]  inCartographica > vol 53 n° 3 (Fall 2018) . - pp 149 - 170 Titre : The impact of map type on the level of student map skills Type de document : Article/Communication Auteurs : Lenka Havelková, Auteur ; Martin Hanus, Auteur Année de publication : 2018 Article en page(s) : pp 149 - 170 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie thématique [Termes descripteurs IGN] carte choroplèthe [Termes descripteurs IGN] cartographie des flux [Termes descripteurs IGN] conception cartographique [Termes descripteurs IGN] diagramme [Termes descripteurs IGN] enseignement secondaire [Termes descripteurs IGN] enseignement supérieur [Termes descripteurs IGN] lecture de carte [Termes descripteurs IGN] République Tchèque [Termes descripteurs IGN] sémiologie graphique [Termes descripteurs IGN] utilisateur civil Résumé : (Auteur) Thematic maps are becoming increasingly important in the current information age, and therefore they have become part of the everyday life of the wider public. Given the number of mapping methods used in thematic cartography, the question arises of what extent the utilized method influences a user’s map use level. For this reason, research has been undertaken with 392 students in the 17–20 age group with the aim of identifying and clarifying the influence of the mapping methods used (specifically choropleth mapping, diagram mapping, qualitative and quantitative line symbols, and area shading). The results have shown that the students were less successful with maps that used quantitative mapping methods than with maps using qualitative or both qualitative and quantitative mapping methods. The differences were most significant in the case of the cognitively demanding map interpretation skill, especially due to the students’ problematic understanding of the very essence of the quantitative methods. The different natures of the tested mapping methods also probably accounted for the identification of various factors explaining the differences in the levels of the work with the given thematic maps among the individual tested students. Numéro de notice : A2018-674 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3138/cart.53.3.2017-0014 date de publication en ligne : 01/10/2018 En ligne : https://doi.org/10.3138/cart.53.3.2017-0014 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91203 [article]

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Point grid map : a new type of thematic map for statistical data associated with geographic points / Mengjie Zhou in Cartography and Geographic Information Science, Vol 44 n° 5 (September 2017)  

Public [article]  inCartography and Geographic Information Science > Vol 44 n° 5 (September 2017) . - pp 374 - 389 Titre : Point grid map : a new type of thematic map for statistical data associated with geographic points Type de document : Article/Communication Auteurs : Mengjie Zhou, Auteur ; Jing Tian, Auteur ; Fuquan Xiong, Auteur ; Rui Wang, Auteur Année de publication : 2017 Article en page(s) : pp 374 - 389 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie thématique [Termes descripteurs IGN] cartographie statistique [Termes descripteurs IGN] diagramme [Termes descripteurs IGN] données socio-économiques [Termes descripteurs IGN] grille [Termes descripteurs IGN] point [Termes descripteurs IGN] représentation cartographique [Termes descripteurs IGN] symbole graphique Résumé : (Auteur) Social, economic, and environmental statistical data associated with geographic points are currently globally available in large amounts. When conventional thematic maps, such as proportional symbol maps or point diagram maps, are used to represent these data, the maps appear cluttered if the point data volumes are relatively large or cover a relatively dense region. To overcome these limitations, we propose a new type of thematic map for statistical data associated with geographic points: the point grid map. In a point grid map, an input point data set is transformed into a grid in which each point is represented by a square grid cell of equal size while preserving the relative position of each point, which leads to a clear and uncluttered appearance, and the grid cells can be shaded or patterned with symbols or diagrams according to the attributes of the points. We present an algorithm to construct a point grid map and test it with several simulated and real data sets. Furthermore, we present some variants of the point grid map. Numéro de notice : A2017-447 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/15230406.2016.1160797 En ligne : http://dx.doi.org/10.1080/15230406.2016.1160797 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86355 [article]

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Development of habitation maps for allergenic plants in Europe / Juliette Delannoy (2017) 

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Variation du niveau d’abstraction dans le cadre de l’opérateur de zoom sémantique / Géraldine Del Mondo in Revue internationale de géomatique, vol 25 n° 2 (juin - août 2015)  

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UML 2.5 / Pascal Roques (2015)

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UML @ Classroom / Martina Seidl (2015)  

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A new database visualization framework for the automatic construction of non-standard charts: re-creating the Chart of Napoleon’s russian campaign of 1812 / Wei Shi in Cartographica, vol 49 n° 4 (December 2014)  

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UML-based approach to developing a CityGML application domain extension / Linda Van Den Brink in Transactions in GIS, vol 17 n° 6 (December 2013)  

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Constrained free space diagrams: a tool for trajectory analysis / Kevin Buchin in International journal of geographical information science IJGIS, vol 24 n°7-8 (july 2010)  

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Semiology of graphics / Jacques Bertin (2010)

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Hierarchical lane-oriented 3D road-network model / Q. Zhu in International journal of geographical information science IJGIS, vol 22 n° 4-5 (april 2008)

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Ogive-based legends for choropleth mapping / R.G. Cromley in Cartography and Geographic Information Science, vol 33 n° 4 (October 2006)

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