| Computer Supported Cooperative Work (CSCW) is a new technology, which syncretizes human's cooperation behavior mode and computer technology. It makes all members of a team complete a common work based on computer technologies.When CSCW is introduced to design area, it is CSCD (Computer Supported Cooperative Design). CSCD is an important domain of CSCW. It studies how to organize and manage the work, the data and the design processes.Based on the relevant research home and abroad, the thesis emphasizes the framework of multi-agent cooperative work, the control policy based on work area object and the implementation means on AutoCAD. And a synchronous cooperative design system is implemented.The thesis introduces the relevant knowledge of CSCW briefly first, then it introduces the available development techniques, which include SCR, AutoLisp, ADS, Object ARX and VBA etc. I take emphasis on the Object ARX which was adopted in this system. According to the experience of development using Object ARX on AutoCAD, I illustrate the problems that should be noticed.I take emphases on some collaborative principles which aim at the means to avoid the collision of the concurrent operation. The reason of the collision is simultaneous access to the same resource of the system. There are three grade modes of sharing the resource, the show grade sharing(tighten coupling), the view grade sharing(middle coupling) and the object grade sharing(loose coupling).I analyse four common collaborative principles in detail in the thesis, then according to the facts of the enterprise, I bring forward the principle of the part of the work mission and the collaborative principle based on area object. The principle of the part of the work mission is that the completion of a complicated work demands many courses knowledge be used integrated. Everyone is limited by his knowledge, he can do only a part of the work, in other words, his activities are limited in a part area of the whole working space.The working area is a part of the whole working space, which is compartmentalized into several parts according to some principle, these parts are independent in a way. One part belongs to a user. The user can operate objects only in his own part, in other part he only can read. Thus a shared object can be operated by only one user, the collision is eliminated and the duty of each employee is made clear.Working area object is abstract conception, it should be mapped to the application conception in different applications. In AutoCAD, it can be mapped to the layer. The whole working space is mapped to the graph document which consists of layers. Any graph object must exist in a layer and no graph object can exist in more than one layers. So the layer meets the request of the working area object, we can use layer as working area object in AutoCAD.Three architectures of collaborative system are discussed in detail in the thesis, they are centralized architecture, decentralized architecture and combination architecture. In centralized architecture, the server takes the responsibility of managing and controlling the whole system, the client only takes charge of serving the user by receiving inputs and showing data; In decentralized architecture, there is no server, all management and control functions are distributed into client agents, every agent is equal to others, no one can control others, they transfer messages to others to inform what happened; In combination architecture, the management and control functions of the system are taken charge of by the server and the client agents together, the server manages the coherence of the data and other global data, the client agents take charge of receiving data from user, showing data to user and some other functions that can be performed at client machine such as examining the user's permission etc.The pure centralized architecture and pure decentralized architecture can't meet the need of collaborative work. The centralized architecture makes the server bottleneck, the decentr...
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