Note that both the location and the time description are rather vague

10 1 Introduction

Ontologies have been identified to be useful for the integration process [43]. Ontologies can be also be used to describe information sources. However, so far we have described the process of seeking concepts. If we look back to the vision of the Semantic Web described in section 1.1 we might also need use colloquial terms to search for locations (e.g., “Frankenwald”, a forest area in Germany) and time (e.g., summer vacation 2003). If we combine these we might get a complex query seeking for a concept@location in time, e.g., “Ac-commodation in Frankenwald during summer vacation 2003”. We note that both the location and the time description are rather vague. Therefore, we need means to represent and reason about vague spatial and temporal infor-mation as well.

Chapter 7 describes some implementation issues of the prototypical BUSTER system. It is a classical client/server system implemented in JAVA where the client can be either an browser-based applet or an application. A system demonstration is also included in this chapter. We describe simple terminological, spatial, and temporal queries and consider also possible com-

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