Ontology-DTD matching algorithm for efficient XML query

XML queries are often expanded based on ontology for broad and in-depth search. But, queries generated from ontology itself are not specific to target documents. Accordingly, the overall search efficiency will deteriorate with those superfluous queries that are not succinct to the target. We suggest an ontology reduction algorithm where the target DTD is matched to ontology such that queries can be minimally expanded. The matched and reduced ontology is successively reusable for the document of a kind. This target-fitted query expansion method is expected to be more efficient than conventional methods in query processing.