1 Introduction
The Semantic Web is an evolving extension of the World Wide Web in which the semantics of information and services on the web is defined, making it possible for the web to understand and satisfy the requests of people and machines to use the web content [27]. A machine requires two essential factors in order to acquire such capabilities: first, a knowledge base that is similar to that possessed by humans; second, the ability to process it in a meaningful manner. This paper focuses mostly on the first point. WordNet is the knowledge base (KB) that is most widely used for Semantic Information Processing (SIP). WordNet developed at Princeton University is a lexical database of English based on psycholinguistics and it has been continuously expanded since 1985 [2]. WordNet has been put to use for SIP such as semantic document indexing [1], semantic document topic detection [3], query expansion [4], ontology extension [5], [22], information retrieval by semantic similarity [26], and knowledge integration [6].