Combining Multiple Ontologies Using ε-Connections

Nowadays, most of the web sites on the internet are consisted of HTML pages. The content of these pages is understandable for humanbeings, but hard for the machines. So to the machines, is not easy for them to handle the informations on the network automately, but in fact the rapid growth of the content on the network urgently requires the computers to be able to understand and deal with web content automatically. To solve this problem, Tim Berners-Lee proposed the vision of the Semantic WEB. The Semantic WEB is an extension of the existing WEB It is not only a platform which can resent the information, but also makes the information on it can be nderstanded and reasoned by the computer.Ontology is one of the bases of the semantic WEB. It uses the way that describing the concepts of web resources and the relationship between the concepts to make the computers can understand and reason the content on the web. Ontology is a clear specification of the conceptual model. The ontology makes the information from different development tools and application platforms can be communicated, shared and resused. Recently, the Semantic WEB and the ontology have received extensive attention, and have been widely used in the area of life science, software engineering, intelligent transportation, and social sciences.When the user’s query involving multiple ontologies, ontology connecting refers to combine some contologies, rather than combine the OWL files. As a way of ontology reusing, it not only can solve the problem of knowledge sharing, but also can provide new ideas and methods for building, maintaining and extending the ontology or knowledge base. Ontology connecting guarantees the operating flexibility and efficiency of reasoning and makes the ontology maintenance more convenient. Ontology connecting can be widely used in many fields like ontology engineering, software engineering and knowledge engineering.Ontology connecting can be roughly divided into two situations. One is that, first dividing the area we interested into some areas which are much somaller and buiding the ontologies respectively. And then connect these ontologies into a big ontology which can describe all the knowdge about the area. This is called Ontology Modularization. In this situation, determining the range of the whole knowledge and each type of knowledge belongs to which areas is the foundation of building the domain ontology. The other one is that, combining any two or more irrelevant small independently developed ontologies existed on the internet into a big module. Under such circumstances, any two ontologies can be connected into a larger modular ontology. It is much closer to the idea of ontology reusing.This paper mainly studies the second form of ontology connecting. On the Semantic WEB, information sources using ontologies to describe their information. People construct and reuse information by compositing these ontologies into an ontology library. In the ontology library, information can be parsed in a unified form. The first kind of ontology connection is for the moment before ontology to be built. It can guide us to build ontology properly. Actually, when we need to use ontology, what is first considered is whether the ontology already exists on the network can be used directly. If these ontologies can be directly connected and reused, it is closer to the idea of ontology reusing.The main tasks and contributions of the thesis are as follows:(1) The building of the China-ASEAN Expo Information Ontology. After studying the principles and methods of ontology building at home and abroad in-depth, according the information resources of China-ASEAN Expo (like the information on the website of the China-ASEAN Expo) and the ontology specification existed aleady, we build the China-ASEAN Expo Information Ontology (caexpo.owl). Basing on this ontology library, we use the description logic reasoning tools (FaCT++) to achieve ASEAN Expo information search service based on semantic.(2) The definition of the link property and the connection rules. Preliminary study of ε-connections theory and the theory of bridge rules, and bring it into the connecting of the multi-OWL2ontologies.ε-connections theory is a framework designed specifically for the abstract description logic system. It bases on the description logic and can be used to achieve OWL2ontology connection.(3) The realizing of multiple OWL2ontologies connecting. Using link property and connection rules, through the ontology edit tool-SWOOP, which bases on ε-connections, realize the target of connecting the China-ASEAN Expo Information Ontology, the business car ontology and the tourism ontology together.(4) The realizing of China-ASEAN Expo Information Retrieval Platform. In order to verify the research in this paper, we design and realize the China-ASEAN Expo Information Retrieval Platform initially. The platform can answer most of the user questions about China-ASEAN Expo.