Metadata Catalogs with Semantic Representations

摘要

Metadata catalogs store descriptive information about logical data items. These catalogs can then be queried to retrieve the particular logical data item that matches the criteria. However, the query has to be formulated in terms of the metadata attributes defined for the catalog. Our work explores the concept of virtual metadata, where catalogs can be queried using metadata attributes not originally defined in the catalog. We use semantic web standards, where new metadata attributes can be taken from shared ontologies and can include expressive axioms to define the new terms. We have implemented a virtual metadata catalog as an extension of the Metadata Catalog Service (MCS), using the Web Ontology Language (OWL) and a reasoning engine to map queries of temporal nature in several metadata catalogs.