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Dépouillements

Can free (and Open Source) software and data be used to underpin a self-paced tutorial on spatial databases? / Claire Ellul in Transactions in GIS, vol 16 n° 4 (August 2012)  

Public [article]  inTransactions in GIS > vol 16 n° 4 (August 2012) . - pp 435 - 454 Titre : Can free (and Open Source) software and data be used to underpin a self-paced tutorial on spatial databases? Type de document : Article/Communication Auteurs : Claire Ellul, Auteur Année de publication : 2012 Article en page(s) : pp 435 - 454 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Formation [Termes IGN] apprentissage (cognition) [Termes IGN] données localisées libres [Termes IGN] logiciel libre [Termes IGN] OpenStreetMap [Termes IGN] pédagogie [Termes IGN] PostGIS [Termes IGN] PostgreSQL [Termes IGN] QGIS Résumé : (Auteur) University College London's Department of Civil, Environmental and Geomatic Engineering (CEGE) offers a number of Masters programmes in topics related to Geomatics, including Surveying, Hydrographic Surveying, Remote Sensing and Geographical Information Science. Data management, and in particular the technology and applications of Spatial Databases, forms a key part of the curriculum on these courses. Interest in Spatial Databases is, however, more widespread – especially with the increasing understanding of the relevance of geospatial techniques to fields as diverse as anthropology and architecture. This article describes the development and evaluation of a self-paced hands-on course on Databases and Spatial Databases for CEGE students, presented to students to complement and enhance in-class teaching. The article focuses on both pedagogical elements of self-paced learning and the suitability of Free and Open Source Software and Open Data (PostgreSQL/PostGIS, Quantum GIS, Open Street Map) for the Spatial Databases curriculum. The resulting material was evaluated by a cohort of 25 students in 2010, and their feedback (very positive) and the overall results provide an interesting insight into suitable methods to employ when teaching technical subjects to a cohort having differing background skill levels. Numéro de notice : A2012-361 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01321.x Date de publication en ligne : 02/08/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01321.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31807 [article]

Geospatial information integration for authoritative and crowd sourced road vector data / H. Du in Transactions in GIS, vol 16 n° 4 (August 2012)  

Public [article]  inTransactions in GIS > vol 16 n° 4 (August 2012) . - pp 455 - 476 Titre : Geospatial information integration for authoritative and crowd sourced road vector data Type de document : Article/Communication Auteurs : H. Du, Auteur ; Natasha Alechina, Auteur ; G. Hart, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 455 - 476 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] appariement de données localisées [Termes IGN] conflation [Termes IGN] données localisées de référence [Termes IGN] données localisées des bénévoles [Termes IGN] données routières [Termes IGN] données vectorielles [Termes IGN] intégration de données [Termes IGN] ontologie Résumé : (Auteur) This article describes results from a research project undertaken to explore the technical issues associated with integrating unstructured crowd sourced data with authoritative national mapping data. The ultimate objective is to develop methodologies to ensure the feature enrichment of authoritative data, using crowd sourced data. Users increasingly find that they wish to use data from both kinds of geographic data sources. Different techniques and methodologies can be developed to solve this problem. In our previous research, a position map matching algorithm was developed for integrating authoritative and crowd sourced road vector data, and showed promising results (Anand et al. 2010). However, especially when integrating different forms of data at the feature level, these techniques are often time consuming and are more computationally intensive than other techniques available. To tackle these problems, this project aims at developing a methodology for automated conflict resolution, linking and merging of geographical information from disparate authoritative and crowd-sourced data sources. This article describes research undertaken by the authors on the design, implementation, and evaluation of algorithms and procedures for producing a coherent ontology from disparate geospatial data sources. To integrate road vector data from disparate sources, the method presented in this article first converts input data sets to ontologies, and then merges these ontologies into a new ontology. This new ontology is then checked and modified to ensure that it is consistent. The developed methodology can deal with topological and geometry inconsistency and provide more flexibility for geospatial information merging. Numéro de notice : A2012-362 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE/SOCIETE NUMERIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01303.x Date de publication en ligne : 03/05/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01303.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31808 [article]

Assessing data completeness of VGI through an automated matching procedure for linear data / T. Koukoletsos in Transactions in GIS, vol 16 n° 4 (August 2012)  

Public [article]  inTransactions in GIS > vol 16 n° 4 (August 2012) . - pp 477 - 498 Titre : Assessing data completeness of VGI through an automated matching procedure for linear data Type de document : Article/Communication Auteurs : T. Koukoletsos, Auteur ; Muki M. Haklay, Auteur ; Claire Ellul, Auteur Année de publication : 2012 Article en page(s) : pp 477 - 498 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] analyse comparative [Termes IGN] appariement automatique [Termes IGN] contrainte géométrique [Termes IGN] données localisées de référence [Termes IGN] données localisées des bénévoles [Termes IGN] exhaustivité des données [Termes IGN] Grande-Bretagne [Termes IGN] objet géographique linéaire [Termes IGN] OpenStreetMap [Termes IGN] programmation par contraintes Résumé : (Auteur) New, free and fast growing spatial data sources have appeared online, based on Volunteered Geographic Information (VGI). OpenStreetMap (OSM) is one of the most representative projects of this trend. Its increasing popularity and density makes the study of its data quality an imperative. A common approach is to compare OSM with a reference dataset. In such cases, data matching is necessary for the comparison to be meaningful, and is usually performed manually at the data preparation stage. This article proposes an automated feature-based matching method specifically designed for VGI, based on a multi-stage approach that combines geometric and attribute constraints. It is applied to the OSM dataset using the official data from Ordnance Survey as the reference dataset. The results are then used to evaluate data completeness of OSM in several case studies in the UK. Numéro de notice : A2012-363 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE/SOCIETE NUMERIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01304.x Date de publication en ligne : 03/05/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01304.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31809 [article]

Exploring geomorphometry through user generated content: Comparing an unsupervised geomorphometric classification with terms attached to georeferenced images in Great Britain / C. Gschwend in Transactions in GIS, vol 16 n° 4 (August 2012)  

Public [article]  inTransactions in GIS > vol 16 n° 4 (August 2012) . - pp 499 - 522 Titre : Exploring geomorphometry through user generated content: Comparing an unsupervised geomorphometric classification with terms attached to georeferenced images in Great Britain Type de document : Article/Communication Auteurs : C. Gschwend, Auteur ; Ross S. Purves, Auteur Année de publication : 2012 Article en page(s) : pp 499 - 522 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] analyse comparative [Termes IGN] classification non dirigée [Termes IGN] données localisées de référence [Termes IGN] données localisées des bénévoles [Termes IGN] géomorphométrie [Termes IGN] Grande-Bretagne [Termes IGN] modèle numérique de surface [Termes IGN] relief Résumé : (Auteur) User generated content such as the georeferenced images and their associated tags found in Flickr provides us with opportunities to explore how the world is described in the non-scientific, everyday language used by contributors. Geomorphometry, the quantitative study of landforms, provides methods to classify Digital Elevation Models (DEMs) according to attributes such as slope and convexity. In this article we compare the terms used in Flickr and Geograph in Great Britian to describe georeferenced images to a quantitative, unsupervised classification of a DEM, using a well established method, and explore the variation of terms across geomorphometric classes and space. Anthropogenic terms are primarily associated with more gentle slopes, while terms which refer to objects such as mountains and waterfalls are typical of steeper slopes. Terms vary both across and within classes, and the source of the user generated content has an influence on the type of term used with Geograph, a collection which aims to document the geography of Great Britain, dominated by features which might be observed on a map. Numéro de notice : A2012-364 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/SOCIETE NUMERIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01307.x Date de publication en ligne : 03/05/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01307.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31810 [article]

Towards usability engineering for online editors of Volunteered Geographic Information: A perspective on learnability / Catherine E. Jones in Transactions in GIS, vol 16 n° 4 (August 2012)  

Public [article]  inTransactions in GIS > vol 16 n° 4 (August 2012) . - pp 523 - 544 Titre : Towards usability engineering for online editors of Volunteered Geographic Information: A perspective on learnability Type de document : Article/Communication Auteurs : Catherine E. Jones, Auteur ; Patrick Weber, Auteur Année de publication : 2012 Article en page(s) : pp 523 - 544 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] apprentissage (cognition) [Termes IGN] convivialité [Termes IGN] données localisées des bénévoles [Termes IGN] interface web [Termes IGN] logiciel d'éditique web [Termes IGN] OpenStreetMap [Termes IGN] optimisation (mathématiques) [Termes IGN] participation du public Résumé : (Auteur) This article presents one of the first systematic usability investigations for a Volunteered Geographic Information (VGI) editor. This research is motivated by the fact that although VGI is now widely consumed, contribution rates are lagging considerably. Compared to traditional GIS interfaces, with complex interfaces resulting in high cognitive loads and barriers to participation, VGI tools and interfaces need to be easy to use and learn to encourage and facilitate contributions. This article develops a case study of OpenStreetMap, one of the most successful VGI projects, and its default editor, Potlatch2. Ten participants with no prior experience of VGI contribution, were instructed to contribute data to OSM in a structured exercise, while being monitored using an eye tracker and audio/video screen capture software. Each participant was asked to Think Aloud, i.e. describe what they were thinking and doing as they completed the tasks. The results highlight significant usability issues impacting learnability, especially from the perspective of a new contributor: hidden functionality, lack of user feedback between interactions and the inefficient and inconsistent placement of functionality and map controls. The facilitation of VGI contributions clearly depends on designing targeted interfaces, optimized to the needs of specific levels of contributors with defined goals and expectations. Numéro de notice : A2012-365 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/SOCIETE NUMERIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01319.x En ligne : https://doi.org/10.1111/j.1467-9671.2012.01319.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31811 [article]

The annotation process in OpenStreetMap / P. Mooney in Transactions in GIS, vol 16 n° 4 (August 2012)  

Public [article]  inTransactions in GIS > vol 16 n° 4 (August 2012) . - pp 561 - 579 Titre : The annotation process in OpenStreetMap Type de document : Article/Communication Auteurs : P. Mooney, Auteur ; P. Corcoran, Auteur Année de publication : 2012 Article en page(s) : pp 561 - 579 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] analyse comparative [Termes IGN] attribut [Termes IGN] données localisées des bénévoles [Termes IGN] objet géographique [Termes IGN] ontologie [Termes IGN] OpenStreetMap Résumé : (Auteur) In this article we describe the analysis of 25,000 objects from the OpenStreetMap (OSM) databases of Ireland, United Kingdom, Germany, and Austria. The objects are selected as exhibiting the characteristics of “heavily edited” objects. We consider “heavily edited” objects as having 15 or more versions over the object's lifetime. Our results indicate that there are some serious issues arising from the way contributors tag or annotate objects in OSM. Values assigned to the “name” and “highway” attributes are often subject to frequent and unexpected change. However, this “tag flip-flopping” is not found to be strongly correlated with increasing numbers of contributors. We also show problems with usage of the OSM ontology/controlled vocabularly. The majority of errors occurring were caused by contributors choosing values from the ontology “by hand” and spelling these values incorrectly. These issues could have a potentially detrimental effect on the quality of OSM data while at the same time damaging the perception of OSM in the GIS community. The current state of tagging and annotation in OSM is not perfect. We feel that the problems identified are a combination of the flexibility of the tagging process in OSM and the lack of a strict mechanism for checking adherence to the OSM ontology for specific core attributes. More studies related to comparing the names of features in OSM to recognized ground-truth datasets are required. Numéro de notice : A2012-366 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/SOCIETE NUMERIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01306.x Date de publication en ligne : 03/05/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01306.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31812 [article]

Understanding design with VGI using an information relevance framework / C. Parker in Transactions in GIS, vol 16 n° 4 (August 2012)  

Public [article]  inTransactions in GIS > vol 16 n° 4 (August 2012) . - pp 545 - 560 Titre : Understanding design with VGI using an information relevance framework Type de document : Article/Communication Auteurs : C. Parker, Auteur ; A. May, Auteur ; V. Mitchell, Auteur Année de publication : 2012 Article en page(s) : pp 545 - 560 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] analyse des besoins [Termes IGN] base de données professionnelles [Termes IGN] conception orientée utilisateur [Termes IGN] données localisées des bénévoles [Termes IGN] utilisateur Résumé : (Auteur) Volunteered Geographic Information (VGI) has the potential to offer benefits to end-users over and above those of Professional Geographic Information (PGI). A multi-methods approach, consisting of participatory observation, focus groups and diary studies, was used to study how VGI and PGI were actually used by a target user group. A theoretical framework of information relevance was used to understand the attributes of information that were most important in relation to the characteristics of the users' activity and their community. The key finding was that the discussion amongst GIS designers should not be whether to choose VGI or PGI as the information data set, but to consider which combination of VGI and PGI relating to different geographic features and task characteristics would best meet the users' needs. VGI is likely to be most relevant to the user when a geographic feature is dynamic rather than static in nature, and can also provide a level of detail that is unlikely to arise through PGI. These findings have implications for how different forms of information are most effective for different usage situations. Above all, a case is presented for the implementation of User Centred Design (UCD) principles when integrating VGI and PGI together in a single mashup-based product. Numéro de notice : A2012-367 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/SOCIETE NUMERIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01302.x Date de publication en ligne : 02/08/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01302.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31813 [article]

Mapping collaboration in open source geospatial ecosystem / Jie Shao in Transactions in GIS, vol 16 n° 4 (August 2012)  

Public [article]  inTransactions in GIS > vol 16 n° 4 (August 2012) . - pp 581 - 597 Titre : Mapping collaboration in open source geospatial ecosystem Type de document : Article/Communication Auteurs : Jie Shao, Auteur ; M. Jackson, Auteur ; Jeremy Morley, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 581 - 597 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] analyse diachronique [Termes IGN] logiciel libre [Termes IGN] programmation informatique [Termes IGN] réseau social Résumé : (Auteur) Over the last decade, there has been a tremendous growth and exploitation of open source geospatial software and technologies. A combination of factors is driving this momentum, including the contributions made by hundreds of developers and the leading role played by the Open Source Geospatial Foundation (OSGeo), aiming primarily to support and promote the collaborative development of open source geospatial technologies and data. This article seeks to map out the social history of collaborative activities within the OSGeo ecosystem. We used the archival logs of developers' contributions, specifically looking for boundary spanning activities where contributions crossed multiple projects. The analysis and visualization of these activities allow us to have a better understanding of the role of boundary spanning in the resourcing of each project, the incubation mechanism advocated by OSGeo, and the significance of the social interrelatedness among projects. The data consisted of the subversion (SVN) commit history made by individual developers in the programming code repository. We applied several network analytical and visualization techniques to explore the data. Our findings indicate that more than one in seven developers spanned multiple projects which potentially had the effects of shaping the projects' directions, and increased knowledge flow and innovation. In addition, the OSGeo's incubation mechanism provided an important encouragement for boundary spanning and increased knowledge sharing. By studying the social history of contributions, further tools can be developed in future to assist tracking of the social history, and make developers mindful of the significance of the interdependence among projects and hence continuously contribute to the health of the OSGeo ecosystem. Numéro de notice : A2012-368 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01305.x Date de publication en ligne : 02/08/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01305.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31814 [article]