Research And Implementation Of Ontology-based Semantic Retrieval Of Educational Resources

With the popularity of the e-Learning, Learning Content Management System (LCMS) becomes a promising research area. It expects to provide standard-based content repositories that allow learners to capture, store, deliver, and manage learning resources. But the substantial impediment to the destination is the fact that the resources are disordered, isolated, and heterogeneous, and there is no common overarching context for the available resources. Additionally, finding the precise information is very difficult because of the lack of semantic description of learning resources. Thus, navigation through a large set of independent resources often leads to users' being lost. The challenge nowadays is to build a scalable learning resource management framework enabling the effective, accurate, semantic-based retrieval of learning resources, in a way that adapts to the characteristics and interests of the users.Semantic retrieval is the retrieval technique that combines information retrieval with user's artificial intelligence and natural language. It analyzes the retrieval requests of and information objects from the understanding of semantic content. It is the retrieval matching mechanism based on concept and its correlative relationship. For the requirement of e-Learning , Semantic Web is a suitable platform to implement various functions of e-Learning .In the semantic web, by adding semantic information for learning resources, making the machine can understand and deal with that automatically and providing intelligent services. In this way, additional semantic tagging of learning resources, which is help the implementation of the semantic link between the resources, support the retrieval of learning resources, improve recall and precision rates, and thus provide suitable learning resources for different users.Three classic traditional information retrieval models and the lack of semantic were introduced firstly, and then import the conception of semantic retrieval ontology-based. Then described the ontology conception, composition and status of semantic retrieval research in detail. Combination the characteristics of learning resources of e-Learning, Ontology-based resource retrieval model were composed with ontology construction, semantic retrieval algorithm and model proposed. Ontology construction was based on seven-step method, combination of CELTSC basic norms of educational resources and the relationship of topic, and described by OWL. Algorithm mainly expand the semantic of user queries, and semantic similarity calculating, was combined of concept similarity and property similarity .At last, developed a prototype system of ontology-based retrieval of learning resources.