Research On Ontology-based Semantic Information Retrieval Model

With the popularization of Internet and the increase of information on the Web,how to retrieve the information we need efficiently from the massive information source is the key problem of information retrieval research.Now the existed search engines are founded based on key word match,which will always return much irrelevant information and can not meet users’demand of recall and precision.When the concept of Ontology being proposed latterly,a lot of research has been done on ontology.Ontology is a conceptual modeling technology on semantic level,with good conceptual level and ability of establishing rich and complex semantic relationships between concepts.In the semantic retrieval system,ontology is the necessary body of knowledge which the system uses to understand the semantic information.So ontology based information retrieval has become an important research topic.This thesis summarizes the domestic and international theory on research of ontology based information retrieval.Based on the logistics domain,this dissertation focus on the construction of the domain ontology,ontology-based semantic annotation of document information and semantic query expand method to users’queries using the domain ontology.Then,introduce a framework of ontology-based semantic information retrieval model,design and realize a prototype.The main works of this thesis are as following:(1)Build a logistics domain ontology Logistics Ontology by analyzing the knowledge of logistics domain and relevant literature,and the construction ideas and methods of domain ontology,more reasonable to achieve the representation of knowledge and organization of information on logistics domain,and continue to improve the ontology which is the support of semantic information search.(2)Based on the collected knowledge documents,realize the semantic annotation of documents according to the methods and processes,and build the semantic index of documents,then construct knowledge information database in order to lay a good foundation for semantic information retrieval system.(3)Research the relevant semantic retrieval technologies,including query expansion which is the technology of analyzing and processing the queries,then apply these methods to implement the model and specific system.Finally,design and develop a semantic information retrieval prototype system Logistics Search based on constructed Logistics Ontology.Experiment shows progress on overcoming the problem in keywords-based retrieval,Logistics Search provides users with good experience of logistics search.