A Hierarchical Consistency Model for Graphics Media in Flexible Collaboration-Transparent Systems

At first, graphics media are abstracted into high level and low level representation. The high level representation includes the design history and feature description. The low level includes topology, geometry and attribution. Secondly, the consistency conditions for different abstracted levels are established. The consistency conditions can be described as strong consistency or weak consistency. They also can be described as strong no-consistency or weak no-consistency. Thirdly, according to layered consistency conditions, different abstracted levels of graphics media are associated with suitable concurrent control methods respectively, which can be strict or relaxed. Fourthly, the strategy how to apply hierarchical consistency model into flexible collaboration transparent infrastructure are analyzed. Finally, we applied the model and methods in our test-bed for collaborative design of engineering graphics.