Modular Construction And Reuse Of Domain Ontology

As ontology becomes a wide range of applications in the computer field, the size and complexity of the ontology are also increasingly expanding. Because the current approaches to ontology construction are lack of a scientific, standardized, and common development process, it leads to the construction and reuse of ontology face the problems which are not conducive to understand, maintaining and sharing. To solve these problems, the modular construction and reuse of ontology become a current hotspot in Semantic Web and ontology engineering.The modular construction of ontology is dividing a complex field to be built into multiple independent and inter-related"sub domain"from top to down, according to certain principles. Then each sub domain is constructed independently and formated multiple"ontology modules". Combining the number of ontology modules according to appropriate principles and approaches, we get a modular ontologies.The idea of modular construction of ontology won't make the scientificity of the definition and structure of knowledge in the whole ontology be affected because of the developer's own limitations of knowledge.Currently, there are many theories and methods about the research of modular construction of ontology. The main ones are: (1) DDL (Distributed Description Logics), (2) C-OWL, (3)ε-Connections theory, (4) P-DL(Package-based Description Logics), (5)D3L(Distributed Dynamic Description Logics). By comparing the characteristics of various methods, and combined with the actual needs of the project, this paper proposes a method of constructing tourism domain ontologies based onε-Connections theory, and use the reasoner—pellet to carry out reasoning on more than one ontology, which based on the improved Tableau algorithm.As knowledge sharing is a very important feature of ontology. In order to better reflect the advantage of this feature in practical applications, this article makes a further study for the reuse of modular ontologies.Ontology reuse is starting from the analysis about user needs, constructing a new ontology on the base of the existing ontology and the existing ontology will appear as part of the new ontology. In other words, in the process of ontology construction, according to the needs of the ontology to be constructed, developers can make some or all knowledge which are associated with the domain knowledge in the exist ontology as a reusable module, and import this reusable module into the new ontology which is being constructed. The idea of ontology reuse make developers not define knowledge which has already been defined in the existing ontology repeatly, when they construct a new ontology.Although the current study for ontology reuse has made some progress, currently the object investigated of these reuse theory is almost focused on a single independent ontology. Because of the limitations of the independent ontology, we can see that, the current algorithm of ontology reuse can not satisfy the efficiency and accuracy at the same time. To resolve this contradiction, a new algorithm for the ontology reuse based on the theory of conservative extension——ERMMO is proposed, which regards the modular ontologies applying the method ofε-Connections as the research object. Besides, this paper verifies the correctness of the algorithm.The main works done in this paper are as follows:(1) Analysing and comparing several main types of modular theories and methods about ontology construction. By comparing and taking actual needs into account, this paper advances a method about building some modular ontologies for tourism domain based onε-Connections theory, and constructing some modular ontologies for tourism domain.(2) Using the reasoner—pellet to carry out reasoning on more than one ontology. Through experiments, we prove that the method about building some modular ontologies for tourism domain in this paper can reduce the complexity of constructing ontologies effectively and is conducive to the resuse of ontologies.(3) Based on the theory of conservative extension, this paper regards the modular ontologies applying the method ofε-Connections as the research object, proposes a new algorithm for the ontology reuse——ERMMO, and verifies the correctness of the algorithm. The ERMMO algorithm ensures high accuracy on the one hand, and on the other hand, greatly improves the efficiency of the algorithm, which based on the theory of conservative extension, and use for extracting a reuse module from a single ontology, at the same time.In conclusion, the current the studies about modular construction and reuse of the ontology have mostly remained at the theoretical level. Through a number of theorems and experiments, this paper verifis the feasibility and correctness of the algorithm proposed in it, which becomes the foundation for further study.