(3)Domain information annotation. The aim of
annotation is to transfer the unstructured information
resource into structured information based on domain
ontolgies DB and annotations are saved into information
database or into files.
(4)Information retrieval. Information retrieval is
mainly concept-matched retrieval and rule-based
reasoning retrieval which has the capability of improving
the sharing and reusing of information resource.
Information retrieval is the key function of unstructured
information management system[7].
(5)Information maintenance. In this function, the
main goals are modifying, deleting and moving domain
ontologies and metadata information of information
resource, so that information resource may keep renewing
and evolving.