Ontology-based Knowledge Of Digital Library Navigation Research

With the development of computer technology and the popularity of the internet, digital libraries have become an important platform for learners to learn. Though there are many learning resources in digital libraries, learners generally only through traditional keyword-based search methods to search for learning resources. However, many digital library users do not have the professional knowledge, so there are lots of problems in determining the value of knowledge, explicating knowledge needs, accessing to knowledge. Sometimes, students are difficult to obtain accurate keywords to search for information. Therefore, we use ontology technology to recognize digital library resources and build a knowledge navigation system. Knowledge navigation system is an important part of the application in the digital library, in which undergraduates, graduate students and the teachers are the main users. They use the navigation system to understand the curriculum development, study courses, search for papers and so on. When learners do not understand some concept, they can click this concept to study by the guidance of the smart navigation.Firstly, this paper introduces the basic knowledge of digital library, semantic web and ontology. Then based on the analysis to three traditional resources organization ways: classification, thesauri, metadata, ontology method is proposed in order to improve the efficiency of digital library knowledge organization, promote the application of digital library development and innovation and realize the sharing and reusing of knowledge. This study focused on using protégétools to create upper subject ontology and database course ontology, saving resources as instances of ontology, using Jena tool to put ontology into database and using the SPARQL language for data querying, and then achieve tree navigation. Knowledge navigation interface displays learning contents in the form of a clarity trees. It provides a complete knowledge system, allowing users to overlook the whole contents to understand the overall situation of a particular field. Learners will reach a different navigation tree along the tree branches by clicking on the relevant concepts to access learning resources.Currently, digital libraries generally use fixed navigation mode, in which the resources of organizations generally use the traditional classification, thesaurus and metadata. Different resources of digital library usually own their independent resource organization manner, learning resources directly stored in database, which should not be updated and maintained easily. Different learning environments build their own learning resources, which can not achieve the cross-platform resources share, wasting a lot of manpower and material resources. Using ontology technology in digital library can add dynamically new learning resources and facilitate the share and reuse of knowledge. Ontology-based navigation system can help learners clarify the interrelationship between the learning concepts. In this navigation system, learners do not need background of the knowledge, they can easily access to relevant learning resources. This navigation system can enhance the utilization of digital library learning resources.