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Ontology-based retrieval of geographic information / M. Lutz in International journal of geographical information science IJGIS, vol 20 n° 3 (march 2006)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 20 n° 3 (march 2006) . - pp 233 - 260 Titre : Ontology-based retrieval of geographic information Type de document : Article/Communication Auteurs : M. Lutz, Auteur ; E. Klien, Auteur Année de publication : 2006 Article en page(s) : pp 233 - 260 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Infrastructure de données [Termes IGN] accès aux données localisées [Termes IGN] catalogue de données localisées [Termes IGN] données localisées [Termes IGN] hétérogénéité sémantique [Termes IGN] interface graphique [Termes IGN] langage de requête [Termes IGN] langage naturel (informatique) [Termes IGN] ontologie [Termes IGN] recherche d'information géographique Résumé : (Auteur) Discovering and accessing suitable geographic information (GI) in the open and distributed environments of current Spatial Data Infrastructures (SDIs) is a crucial task. Catalogues provide searchable repositories of information descriptions, but the mechanisms to support GI retrieval are still insufficient. Problems of semantic heterogeneity caused by the ambiguity of natural language can arise during keyword-based search in catalogues and when formulating a query to access the discovered data. In this paper, we present an approach to ontology based GI retrieval that contributes to solving existing problems of semantic heterogeneity and hides most of the complexity of the required procedure from the requester. A query language and graphical user interface allow a requester to intuitively formulate a query using a well-known domain vocabulary. From this query, an ontology concept is derived, which is then used to search a catalogue for a data source that provides all the information required to answer the requester's query. If a suitable data source is discovered, the relevant data are accessed through a standardized interface. The approach is implemented through several components that can be used as an extension to standard SDIs. Numéro de notice : A2006-091 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810500287107 En ligne : https://doi.org/10.1080/13658810500287107 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27818 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-06031	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-06032	RAB	Revue	Centre de documentation	En réserve L003	Disponible

3D simulation of soft-objects / D.Y. Shen in International journal of geographical information science IJGIS, vol 20 n° 3 (march 2006)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 20 n° 3 (march 2006) . - pp 261 - 271 Titre : 3D simulation of soft-objects Type de document : Article/Communication Auteurs : D.Y. Shen, Auteur ; K. Takara, Auteur ; et al., Auteur Année de publication : 2006 Article en page(s) : pp 261 - 271 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] animation graphique [Termes IGN] effondrement de terrain [Termes IGN] érosion [Termes IGN] modélisation 3D [Termes IGN] objet géographique [Termes IGN] SIG 3D [Termes IGN] simulation 3D [Termes IGN] système d'information géographique [Termes IGN] voxel Résumé : (Auteur) In terms of geometry, existing approaches for 3D GIS modelling can be classified into three types: surface-based, volume-based, and hybrids. These approaches are suitable for representing rigid geo-objects, but so far there are no ideal GIS modelling methods for simulation of soft geo-objects such as flowing water and soil. In this study, a GIS flow element (FE) and GIS soft voxel (SV) were used for simulation of overland flow and soil erosion. The length of a GIS FE is directly proportional to the velocity of overland flow, while the inclination of a GIS FE represents the direction of overland flow. The GIS SV is generated by implicit functions, which can be utilized to create a smoothed surface. This study reveals that GIS FEs can realistically represent the dynamics and stochastics of soft geo-objects, while GIS SVs can simulate deformation of soft geo-objects. Moreover, both of these approaches can reflect geoscientific laws because the animation of 3D scenarios is controlled by geoscientific models. Numéro de notice : A2006-092 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/13658810500287149 En ligne : https://doi.org/10.1080/13658810500287149 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27819 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-06031	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-06032	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Dynamic simplification and visualization of large maps / N. Mustafa in International journal of geographical information science IJGIS, vol 20 n° 3 (march 2006)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 20 n° 3 (march 2006) . - pp 273 - 302 Titre : Dynamic simplification and visualization of large maps Type de document : Article/Communication Auteurs : N. Mustafa, Auteur Année de publication : 2006 Article en page(s) : pp 273 - 302 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] généralisation cartographique automatisée [Termes IGN] interactivité [Termes IGN] simplification de contour [Termes IGN] visualisation cartographique Résumé : (Auteur) In this paper, we present an algorithm that performs simplification of large geographical maps through a novel use of graphics hardware. Given a map as a collection of non-intersecting chains and a tolerance parameter for each chain, we produce a simplified map that resembles the original map, satisfying the condition that the distance between each point on the simplified chain and the original chain is within the given tolerance parameter, and that no two chains intersect. In conjunction with this, we also present an out-of-core system for interactive visualization of these maps. We represent the maps hierarchically and employ different pruning strategies to accelerate the rendering. Our algorithm uses a parallel approach to do rendering as well as fetching data from the disk in a synchronous manner. We have applied our algorithm to a gigabyte sized map dataset. The memory overhead of our algorithm (the amount of main memory it requires) is output sensitive and is typically tens of megabytes, much smaller than the actual data size. Numéro de notice : A2006-093 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1080/13658810500390794 En ligne : https://doi.org/10.1080/13658810500390794 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27820 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-06031	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-06032	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Indexing network-constrained trajectories for connectivity-based queries / X. Li in International journal of geographical information science IJGIS, vol 20 n° 3 (march 2006)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 20 n° 3 (march 2006) . - pp 303 - 328 Titre : Indexing network-constrained trajectories for connectivity-based queries Type de document : Article/Communication Auteurs : X. Li, Auteur ; H. Lin, Auteur Année de publication : 2006 Article en page(s) : pp 303 - 328 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] accès aux données localisées [Termes IGN] connexité (topologie) [Termes IGN] indexation spatiale [Termes IGN] objet mobile [Termes IGN] positionnement cinématique [Termes IGN] requête spatiotemporelle [Termes IGN] système d'information géographique Résumé : (Auteur) Recent advances in positioning and communication technologies have made it possible to collect trajectories of moving objects, and thus, corresponding applications that handle trajectories come into sight, e.g. applying vehicle trajectories to traffic studies, where various queries about trajectories are necessary. However, due to their special spatio-temporal query conditions, trajectory queries are different from existing GIS queries, and there is still a lack of efficient data-access methods to support queries about trajectories. In view of this, we develop a data-access method, named a Topology-based Mixed Index Structure (TMIS), to index network-constrained trajectories for connectivity-based queries. The TMIS indeed is not a novel index structure but a novel combination of simple and classical index structures linked by the topology of a network. The TMIS can support more query types through different combinations of simple and classical index structures and can be applied to a large network. Existing database management systems can be employed to implement the TMIS. In this paper, we first define network-constrained trajectories and connectivity-based queries, and then introduce the principles, architecture, algorithms, and query processing of the TMIS. Finally, we implement the TMIS and validate it through a series of analyses and experiments. Numéro de notice : A2006-094 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810500432570 En ligne : https://doi.org/10.1080/13658810500432570 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27821 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-06031	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-06032	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Understanding SDI: complexity and institutionalization / W.H. Erik De Man in International journal of geographical information science IJGIS, vol 20 n° 3 (march 2006)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 20 n° 3 (march 2006) . - pp 329 - 343 Titre : Understanding SDI: complexity and institutionalization Type de document : Article/Communication Auteurs : W.H. Erik De Man, Auteur Année de publication : 2006 Article en page(s) : pp 329 - 343 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Infrastructure de données [Termes IGN] accès aux données localisées [Termes IGN] complexité [Termes IGN] évaluation des données [Termes IGN] infrastructure européenne de données localisées [Termes IGN] partage de données localisées Résumé : (Auteur) Notwithstanding impressive developments in SDI in exchange, sharing, accessibility, and use of spatial data, its operational implementation appears sometimes problematic. This paper explores conditions and factors for effective and sustainable use of SDI and suggests that the inherent complexity of SDI requires a multi-faceted way of monitoring and evaluation rather than confinement to the limited scope of objective oriented performance only. Critical issues, challenges, and dilemmas can be identified while looking at SDI as facilitator of communication, as networked infrastructure, as socio-technical actor-network, as common-pool resource, and as community of practice. Finally, the paper suggests institutionalization of SDI within a spatial data community as a unifying concept towards effectiveness and sustainability of SDI initiatives while recognizing their inherent complexities. Institutionalization is the process in which the SDI will gain an institutional (structural) role within the spatial data community in which it is embedded and consequently contributes to effective exchange, sharing, accessibility, and use of spatial data. The paper also discusses some operational conditions to this end. Numéro de notice : A2006-095 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810500399688 En ligne : https://doi.org/10.1080/13658810500399688 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27822 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-06031	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-06032	RAB	Revue	Centre de documentation	En réserve L003	Disponible