Management And Retrieval Of Web Services Based On Formal Concept Analysis

As the development of e-commerce and the Internet, Web service becomes one of the most promising Web-based application integrating technology in recent years. Much research work has been done in relevant areas of Web services, including the abstraction and description of Web services, semantics of Web services and interoperation of Web services on semantic level, community of Web services, service composition, service verification and testing, effective management and organization of Web services, service selection, matchmaking and alternate algorithms and QoS etc. Based on this research, in this paper, we give deeply study and discuss on the problem of effective management of Web services and retrieval of Web services and their alternates. We propose a conceptual management technique and relevant algorithms by applying Formal Concept Analysis (FCA) on Web Services. We prove theoretically the correctness of our algorithms and relative theories, and verify the effectiveness of our approach by experiments. The contributions of this thesis include:1. A novel structure, named service lattice, has been proposed using the underlying semantic relationship between Web services which is discovered by applying FCA to Web service repositories. And with the service lattice, we can manage Web services in an efficient way by grouping Web services conceptually in the lattice. At the same time, we develop the algorithms for generating formal concepts, building service lattice and incremental maintenance of service lattice. We conduct some experiments to verify the effectiveness of the algorithms.2. We propose the approach of retrieving Web services and their alternates on service lattice, including some useful concepts and algorithms. As we know, a good service management can support service retrieval effectively. In order to investigate the performance of our service lattice, we develop the service retrieval approach based on service lattice and the corresponding algorithms by using the relationship between the formal concepts in the lattice. We study especially the problem of retrieving alternate Web services, and develop the algorithms and method to implement the retrieval of alternate Web services on service lattice. The experimental results show that retrieval of (alternate) Web services based on service lattice has good efficiency and scalability.3. We propose Vector Service Lattice (VSL) , which enables service lattice tosupport vector based retrieval and extends service lattice by introducing k-item vector of service operations. And in order to build the VSL, we develop the algorithms for discovering the service operation vector concepts and the selection method of k-item set of service operations. We build a new vector model for service operation by adding the conceptual grouping information gained from VSL into the original weight vector of service operations. By computing the relationship between the extended service operation vectors and retrieval vector, we can retrieval of service operation in a fast way. By analyzing the experiment results, we find that our approach can improve the efficiency and accuracy of retrieving Web service at operation level.Our method of managing web service with FCA is the first time for service management by exploiting the underlying semantics of Web services. Both theoretical analysis and experimental results show the proposed methods are good at service management and retrieval. Our research has great importance both in theoretical and applied area.