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Privacy-aware visualization of volunteered geographic information (VGI) to analyze spatial activity: A benchmark implementation / Alexander Dunkel in ISPRS International journal of geo-information, vol 9 n° 10 (October 2020)  

Public [article]  inISPRS International journal of geo-information > vol 9 n° 10 (October 2020) . - 20 p. Titre : Privacy-aware visualization of volunteered geographic information (VGI) to analyze spatial activity: A benchmark implementation Type de document : Article/Communication Auteurs : Alexander Dunkel, Auteur ; Marc Löchner, Auteur ; Dirk Burghardt, Auteur Année de publication : 2020 Article en page(s) : 20 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes descripteurs IGN] analyse spatiale [Termes descripteurs IGN] base de données d'images [Termes descripteurs IGN] chaîne de traitement [Termes descripteurs IGN] confidentialité [Termes descripteurs IGN] données localisées des bénévoles [Termes descripteurs IGN] protection de la vie privée [Termes descripteurs IGN] réseau social [Termes descripteurs IGN] ressources naturelles [Termes descripteurs IGN] réutilisation des données [Termes descripteurs IGN] visualisation de données Résumé : (auteur) Through volunteering data, people can help assess information on various aspects of their surrounding environment. Particularly in natural resource management, Volunteered Geographic Information (VGI) is increasingly recognized as a significant resource, for example, supporting visitation pattern analysis to evaluate collective values and improve natural well-being. In recent years, however, user privacy has become an increasingly important consideration. Potential conflicts often emerge from the fact that VGI can be re-used in contexts not originally considered by volunteers. Addressing these privacy conflicts is particularly problematic in natural resource management, where visualizations are often explorative, with multifaceted and sometimes initially unknown sets of analysis outcomes. In this paper, we present an integrated and component-based approach to privacy-aware visualization of VGI, specifically suited for application to natural resource management. As a key component, HyperLogLog (HLL)—a data abstraction format—is used to allow estimation of results, instead of more accurate measurements. While HLL alone cannot preserve privacy, it can be combined with existing approaches to improve privacy while, at the same time, maintaining some flexibility of analysis. Together, these components make it possible to gradually reduce privacy risks for volunteers at various steps of the analytical process. A specific use case demonstration is provided, based on a global, publicly-available dataset that contains 100 million photos shared by 581,099 users under Creative Commons licenses. Both the data processing pipeline and resulting dataset are made available, allowing transparent benchmarking of the privacy–utility tradeoffs. Numéro de notice : A2020-664 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi9100607 date de publication en ligne : 20/10/2020 En ligne : https://doi.org/10.3390/ijgi9100607 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96141 [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 International Encyclopedia of Geography: People, The Earth, Environment, and Technology, ch. Map Generalization / William A Mackaness (2017)  

Public Titre de série : The International Encyclopedia of Geography: People, The Earth, Environment, and Technology, ch Titre : Map Generalization Type de document : Chapitre/Contribution Auteurs : William A Mackaness, Auteur ; Dirk Burghardt, Auteur ; Cécile Duchêne , Auteur Editeur : New York, Londres, Hoboken (New Jersey), ... : John Wiley & Sons Année de publication : 2017 Note générale : bibliographie Langues : Anglais (eng) Résumé : (auteur) Map generalization is concerned with the optimal display of geographic information in map form. It involves the careful selection of data and the use of a range of abstraction techniques that seek to give emphasis to what is important, while still including sufficient contextualizing information. If geographic phenomena are stored at fine levels of detail, the goal of automated map generalization is to derive maps at coarser (smaller) scales. Traditionally, the focus has been on paper maps, but increasingly map generalization services are available via the web, and accessible to users with relatively little cartographic knowledge who wish to integrate data from multiple sources (including their own). These high levels of automation require us to make explicit the relationships and behaviors among geographic phenomena, in order that we can reason about the complex decision‐making process that is cartographic design. Numéro de notice : H2017-029 Affiliation des auteurs : LaSTIG COGIT+Ext (2012-2019) Thématique : GEOMATIQUE Nature : Chapître / contribution nature-HAL : ChOuvrScient DOI : 10.1002/9781118786352.wbieg1015 date de publication en ligne : 06/03/2017 En ligne : https://doi.org/10.1002/9781118786352.wbieg1015 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91924

Automatic delineation of built-up area at urban block level from topographic maps / Sebastian Muhs in Computers, Environment and Urban Systems, vol 58 (July 2016)  

Public [article]  inComputers, Environment and Urban Systems > vol 58 (July 2016) . - pp 71 - 84 Titre : Automatic delineation of built-up area at urban block level from topographic maps Type de document : Article/Communication Auteurs : Sebastian Muhs, Auteur ; Hendrik Herold, Auteur ; Gotthard Meinel, Auteur ; Dirk Burghardt, Auteur ; Odette Kretschmer, Auteur Année de publication : 2016 Article en page(s) : pp 71 - 84 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes descripteurs IGN] analyse d'image numérique [Termes descripteurs IGN] base de données historiques [Termes descripteurs IGN] carte topographique [Termes descripteurs IGN] détection du bâti [Termes descripteurs IGN] extraction semi-automatique [Termes descripteurs IGN] îlot urbain [Termes descripteurs IGN] vision par ordinateur [Termes descripteurs IGN] zone urbaine Résumé : (auteur) To comprehensively study and better understand urban dynamic processes — such as densification, growth and sprawl, or shrinkage — spatio-temporal databases that allow to track changes of geographic objects like buildings and urban blocks are essential. While comprehensive databases exist for contemporary data, they usually lack a historic dimension. The manual constitution of historic geographic data, be it based on historic maps or aerial images, is a time consuming and laborious process, however. Therefore, we present an approach to semi-automatically extract this data from binary topographic maps with regard to built-up areas at urban block level. The suitability of topographic maps for historic urban analysis has been proven in previous research. To overcome the challenges that are inherent in scanned topographic maps in regard to digital image interpretation we designed a modular process. Among others, these challenges include fused and (multi-)fragmented map objects caused by the overlap of competing content layers in one single binary map. After a preliminary separation of individual map object layers from the map content, the process follows a two-stage top-down approach. At first, the map is organized into street blocks, which after that are re-delineated in regard to built-up area. In doing so, we achieve correctness values ranging from 0.97 to 0.93 for three study sites in Germany. With an increasing number of projects that provide historic topographic maps as georeferenced digital data, our process represents a promising approach to efficiently prepare these historic data for integration into a spatio-temporal database with minimal user intervention. Numéro de notice : A2016-404 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.compenvurbsys.2016.04.001 En ligne : http://dx.doi.org/10.1016/j.compenvurbsys.2016.04.001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81221 [article]

Automated generalisation within NMAS in 2016 / Jantien E. Stoter (2016)  

Public contenu dans EuroSDR contributions to ISPRS Congress XXIII, 12 - 19 July 2016, Special Session 12 – EuroSDR Prague, Czech Republic / European Spatial Data Research EuroSDR (02/2017)   23th ISPRS international congress, 4. Commission IV / Lena Halounova (2016)   Titre : Automated generalisation within NMAS in 2016 Type de document : Article/Communication Auteurs : Jantien E. Stoter, Auteur ; Vincent Van Altena, Auteur ; Marc Post, Auteur ; Dirk Burghardt, Auteur ; Cécile Duchêne , Auteur Editeur : International Society for Photogrammetry and Remote Sensing ISPRS Année de publication : 2016 Collection : International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences, ISSN 1682-1750 num. XLI-B4 Importance : pp 647 - 652 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] base de données multi-représentation [Termes descripteurs IGN] chaîne de traitement [Termes descripteurs IGN] état de l'art [Termes descripteurs IGN] généralisation cartographique automatisée [Termes descripteurs IGN] organisme cartographique national [Vedettes matières IGN] Généralisation Résumé : (auteur) Producing maps and geo-data at different scales is traditionally one of the main tasks of National (and regional) Mapping Agencies (NMAs). The derivation of low-scale maps (i.e. with less detail) from large-scale maps (with more detail), i.e. generalisation, used to be a manual task of cartographers. With the need for more up-to-date data as well as the development of automated generalisation solutions in both research and industry, NMAs are implementing automated generalisation production lines. To exchange experiences and identify remaining issues, a workshop was organised end 2015 by the Commission on Generalisation and Multirepresentation of the International Cartographic Association and the Commission on Modelling and Processing of the European Spatial Data Research. This paper reports about the workshop outcomes. It shows that, most NMAs have implemented a certain form of automation in their workflows, varying from generalisation of certain features while still maintaining a manual workflow; semiautomated editing and generalisation to a fully automated procedure. Numéro de notice : C2016-015 Affiliation des auteurs : IGN+Ext (2012-2019) Thématique : GEOMATIQUE Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.5194/isprs-archives-XLI-B4-647-2016 date de publication en ligne : 14/06/2016 En ligne : http://doi.org/10.5194/isprs-archives-XLI-B4-647-2016 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84320

Thematic workshop on building an ontology of generalisation for on-demand mapping / William A Mackaness (2015)    

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Abstracting geographic information in a data rich world, ch. 1. Map generalisation: fundamental to the modelling and understanding of geographic space / William A Mackaness (2014)  

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Abstracting geographic information in a data rich world, ch. 11. Generalisation in practice within national mapping agencies / Cécile Duchêne (2014)  

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Abstracting geographic information in a data rich world, ch. 12. Conclusion: major achievements and research challenges in generalisation / Dirk Burghardt (2014)  

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Abstracting geographic information in a data rich world / Dirk Burghardt (2014)

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Content zooming and information exploration for web and mobile maps. Adaptation of real-time map generalisation to the information seeking strategies of web and mobile users / Pia Bereuter in Revue internationale de géomatique, vol 23 n° 3 - 4 (septembre 2013 - février 2014)

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Cartography from pole to pole [ICC 2013] / Manfred F. Buchroithner (2013)

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Proceedings of the 26th International Cartographic Conference, ICC '13 [ICC 2013] / Manfred F. Buchroithner (2013)  

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Relation modelling within multiple representation databases and generalisation services / Dirk Burghardt in Cartographic journal (the), vol 47 n° 3 (August 2010)  

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State-of-the-art of automated generalisation in commercial software / Jantien E. Stoter (2010) 

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