Research On System Of Service Web-Oriented E-government

Electronic government based on Internet is becoming the new government mode. For the heterogeneous and autonomy of different business system, linking and cooperative working is difficult. Ontology-Driven Service Web-Oriented Multilayered Architecture (ODSOMA) architecture is proposed which integrates dispersive and loosely coupled sub-systems into a uniform application system. The main results are as follows.(1) Service-oriented application integration. A behavior based transition model is employed to describe web services, extending the original description, so that reusing is supported. Through a deep study of the automatic service composition based on PDL, the shortcoming of the approach is presented and a novel automatic service composition based on "virtual service" is proposed. Importing "virtual service" can resolve the selecting problem in the PDL based automatic service composition systems, so that it can achieve the composition tasks much better.(2) Mobile Agent based orchestration of the service composition system. There are a lot of advantages of mobile agent to achieve the composite service. It not only supports the innovation of the composition process, but also decreases the bandwidth distinctively. The latter is very important to support the service composition in a pervasive environment, because the bandwidth is relatively small and the connection is not stable. The formal definitions of Agent and the composition process are proposed. And section 4 also gives the matching rules from the process to the task of Agent and the algorithms from the Agent's task to its physical behaviors.(3) Heterogeneous message transformation based on previous knowledge. Although the heterogeneous applications are wrapped as web services, only the syntax heterogeneities are resolved while the semantic conflicts still exist. A transformation mechanism for resolving the heterogeneous messages is proposed in this paper. During the execution of the process of web services, the converting engine can automatically pick up useful messages from the intermediate results of previous services and convert them into the desired format, so that they can be composed into the request message to invoke the following web services.(4) Security model based on identity authentication and access control. This thesis also presents a detailed study of the network security of the E-government. And then, combined with the security requirements of E-government WebFilter, an integrative platform for identity authentication and access control of E-government is proposed. The design pattern, function and components of the platform are given in detail, the key technology of the platform and the methodology of how to achieve are described too. Actually, this platform builds a safe way for transforming data between client and server, and it also give an effective mechanism for the safety of the other Internet based applications.