Omar Boucelma

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Despite various interoperability recommendations, heterogeneity of Geographic Information Systems (GIS) is still an issue. This led to an increasing need for a data integration system that allows transparent and uniform access to spatial data disseminated over a network. In this paper, we describe the internals of query processing in the VirGIS mediation(More)
The access and exploitation of integrated Web data repositories and applications is critical for life science. Biologists design protocols that typically rely on complex query pipelines accessing various biological Web resources (data sources and tools) to constitute data sets for analysis and mining. Web integration platforms are needed to allow biologists(More)
Geographic data have been collected for centuries and are available in a wide variety of formats and supports. VirGIS provides an integrated view of the data, and a geographical query language to access and manipulate integrated geographical data. Typical mediation approaches are data-driven and do not address the problem of integration of query(More)
XML has established itself as the standard for representing data in scientific and business applications, leading to several dialects and tools for XML data processing. In this paper we are interested in querying geographic data encoded in GML, the Geography Markup Language adopted by the OpenGIS consortium (OGC) for the description, transmission and(More)
In this paper, we propose a framework for dynamic Web services customization. The basic idea consists to automatically transform Web services configurations, published in services directories, into other ones better suited for client needs. The goal of this automatic transformation, based mainly on dynamic Web services composition, is twofold. On the one(More)
In recent times, the proliferation of spatial data on the Internet is beginning to allow a much larger audience to access and share data currently available in various Geographic Information Systems (GISs). Unfortunately, even if the user can potentially access a huge amount of data, often, she has not enough knowledge about the spatial domain she wants to(More)