Universal information retrieval system in semantic Web environment

Interoperability between different metadata schemas and data is an important issue for various semantic Web-related applications. A metadata schema described in XML schema can´t be used with other metadata schema in a semantically interoperable way. As part of an attempt to build a retrieval system that uses various metadata standards such as MPEG-7 and Dublin Core in a semantic Web environment, we first developed a method for automatically converting the XML schema into a RDF schema. Our approach is to develop a set of conversion rules for XML schema definitions into RDF schema definitions, rather than interpreting the semantics of metadata schemas. We observe that some schema descriptions cannot be expressed in RDF schema, because they are purely syntactic and/or structural constraints. However, we believe that this limitation does not hinder semantic level information retrieval with the metadata description in RDF and associated metadata schema in RDF schema.