Sommaire de la publication

Sommaire de la publication

LĂ©tourneau, F., Y. BĂ©dard & B. Moulin, 1998, Perspectives d’utilisation du concept d’entrepĂ´t de donnĂ©es pour les gĂ©orĂ©pertoires sur Internet, Geomatica, Journal of the Canadian Institute of Geomatics, Vol. 52, No. 2, pp. 145-163

Résumé

L’hĂ©tĂ©rogĂ©nĂ©itĂ© des gĂ©orĂ©pertoires dans internet entraĂ®ne un certain nombre de problèmes pour l’usager qui dĂ©sire en consulter plusieurs afin de trouver l’information qu’il cherche. Cette hĂ©tĂ©rogĂ©nĂ©itĂ© se dĂ©taille ainsi: hĂ©tĂ©rogĂ©nĂ©itĂ© du contenu, de la structure et des rĂ©fĂ©rentiels spatiaux, disparitĂ©s sĂ©mantiques et absence d’outils d’aide Ă  la sĂ©lection des documents. Une solution envisagĂ©e pour rĂ©soudre ces problèmes consiste Ă  intĂ©grer le contenu des gĂ©orĂ©pertoires hĂ©tĂ©rogènes dans un entrepĂ´ts de donnĂ©es. Toutefois, nous ne connaissons pas la faisabilitĂ© conceptuelle, opĂ©rationnelle ou technique de cette approche. Nous avons donc analysĂ© le potentiel de l’approche entrepĂ´t de donnĂ©es pour produire un guichet unique pour un ensemble de gĂ©orĂ©pertoires dans Internet. Parallèlement Ă  cette Ă©tude, nous avons conçu le prototype SOS-DS (Système optimal de sĂ©lection des donnĂ©es spatiales) accessible via Internet. Ce prototype nous a permis de valider certains concepts de la recherche thĂ©orique ainsi que de proposer des mĂ©thodes de requĂŞte innovatrices pour exploiter Ă  fond les donnĂ©es de l’entrepĂ´t de donnĂ©es. Cet article prĂ©sente la dĂ©marche suivie ainsi que les principaux rĂ©sultats obtenus au cours de ce projet de recherche rĂ©alisĂ© par l’auteur principal, sous la supervision des coauteurs.

Abstract

The implementation by different organizations of Georeferenced Digital Libraries (GDL) on the World Wide Web creates several problems for users who must query these heterogeneous libraries for a given territory. They face differences in contents, structures, spatial reference systems, semantics, interfaces, etc. In addition, these GDLs usually do not provide on-line support for the users who want to select the best products according to his needs. Our solution to these problems is to import some metadata from these GDLs to process their data and to integrate the results in an homogeneous spatial data warehouse which serves as a « one-step » query engine. Such solution is known in computer sciences as « data warehousing » and is theoretically very promising. However, there was a high level of uncertainty with regard to such a solution: conceptually, operationally and technically. Consequently, we started a research and development project to further study these theoretical possibilities and to experiment the resulting concepts. This resulted in a prototype called SOSSD (System for the Optimal Selection of Spatial Data) developed by the main author for his M.Sc. with the two co-authors as advisors. This paper presents our theoretical approach as well as the results obteained with SOSSD, including the implementation od a spatial data warehouse on the web and the use of « fuzzy logic » to support the users in their queries.