Research And Implementation Of Cooperative Design Platform Based On Real-time Interacting With Diagrams And Text In Internet Environment

The develop trend of CSCW and cooperative design platform brings up the concept of a cooperative design platform based on real-time interacting with diagrams and text in internet environment. In this paper the concept was defined and its basic designing requirements are given. The involved key technologies -system hierarchy, user interface, consistency maintenance, concurrent control, access control and record management are studied. The different solutions of them are compared and their applicability in cooperative design platform based on real-time interacting with diagrams and text in internet environment is demonstrated.To solve the problem of concurrency control of shared objects in a real-time groupware system with a synchronized and centralized structure, a concurrent control algorithm based on time stamps and operation transposition is given. It realizes the objects consistence between different users and enhances the success rate of operations of users who have lower speed of access to the network.To solve the problem of communication between clients, in this paper, a communication model based on communication agent is given and implemented, which can be applied in the cooperative design platform with B-S structure and using of Java Applet. The model implements the interactive communication between clients by the delivery of KQML compatible messages between server and applet. The delivery is based on TCP/IP and JAVA Socket API. The model divides information communication from information process, which offers a strong logic, a good feasibility and a great extensibility. It is a new method on solving the problem of message communication between cooperative users. Based on above researches, we implement a prototype interactive system of diagram and text RITIS (Real-time Image and Text Interactive System), which consists of server part and client part and support real-time interacting with diagram and text on the internet. It takes the mixed form of centralized structure and peer-to-peer structure, offers a multi-user interface of WYSIWIS, has strict consistence maintenance and concurrent control mechanism and integrates the record manage management and access control into the real-time interacting and delivers messages between users by using of communication agents, which has a practicable performance. The system is a quest for developing cooperative platform based on Web with JAVA Applet, and it can be extended to the interface of other branches of CSCW application.