Ontology Of Place Names And Their Names Retrieval Services

With the rapid development of network technology, the World Wide Web has become the largest information repository of human. When facing the complicated network resource, how to retrieve the information required, has become the research focus of the network technology. Geographic Information Retrieval, which called GIR for short, is one of the important research directions of information retrieval technology. GIR returns the documents related to geographic information according to the query scope. Geographical knowledge base is the basic of GIR, which stores the knowledge of geographic entity including its names, types, attributes and relations. At present, the two main kinds of geographical knowledge base are gazetteer and address library, which are very useful to eliminate ambiguity of place name. However, they are the list of place name, lack expression of semantic information. Although they can achieve the reasoning of spatial relation according to the coverage record of entities'edge,-the efficiency is very low.Base on the disadvantages of gazetteer and address library,we research the model of place name organization supporting spatial reasoning, that is place-name ontology. Because place-name ontology is constructed on the basic of expressing semantic characters and spatial characters of place-name entities, it supports the expression of semantic information and improves the efficiency of spatial reasoning.It is necessary to explicitly express the relationships among concepts when constructing ontology. In the place-name ontology, we regard each place-name entity as one concept, whose spatial relations are also regarded as the relations of concept. In this paper, we express the location of place-name entity qualitatively in the coordinate frame of Beijing city firstly and define the concept of place-name entity, combining the types of place-name entities. And then select the landmarks which play important parts in city positioning of Beijing to compose the reference system of landmark and express the orientation relation using four-orientation model, topology relation and distance relation between the landmarks and the place-name entities. These relations form the relation collection of place-name entity. Finally, express the place-name entity in the form of the triples and construct the place-name ontology of Beijing city by using the software protege combined with OWL ontology language. On the basics of place-name ontology, we research the service frame of geographic information and design the prototype system of geographic information.