To Örebro University

The new era of semantic web has enabled users to extract semantically relevant data from the web. The backbone of the semantic web is a shared uniform structure which defines how web information is split up regardless of the implementation language or the syntax used to represent the data. This structure is known as an ontology.

As information on the web increases significantly in size, Web ontologies also tend to grow bigger to such an extent that they become too large to be used in their entirety by any single application. This has stimulated our work in the area of sub-ontology extraction where each user may extract optimized sub-ontologies from an existing base ontology.

Sub-ontologies are valid independent ontologies, known as materialized ontologies, that are specifically extracted to meet certain needs. Because of the size of the original ontology, the process of repeatedly iterating the millions of nodes and relationships to form an optimized sub-ontology can be very extensive. Therefore we have identified the need for a distributed approach to the extraction process. As ontologies are currently widely used, our proposed approach for distributed ontology extraction will play an important role in improving the efficiency of information retrieval.