1、,支持网络化协同设计CAD的关键技术与实现方法分析,网络化协同cad设计的两大问题,一、设计的冲突二、文件的传输速度,解决方法,对于问题一A Study on Collaborative Design Considering Features of Design利用数据包络分析方法（DEA）计算设计的效率和权衡的方法(STM)发现并解决冲突。,DEA STM,在约束条件下，使效率达到最大,解决方法,对于问题二Geometric Simplification to Stream 3D Models for Collaborative Product Design利用三维流技术进行模型的简化、传输
2、及还原,解决方法,对于问题二,三维流技术,实现流技术的关键算法,三维模型的几何简化,在该文献中，提出了一种新的简化算法，来确定死亡顶点及崩溃边、崩溃方向,顶点分类,(the non-simple vertex here is either an interior edge one or a corner one).,Criterion 1A for example,Shortest edge -决定崩溃 崩溃方向-Error Function: Ei = | Ai A0 | where i = 1 or 2 (1) Where A0 refers to the surface area of
3、all triangles sharing at least one of the vertices of the selected edge, and Ai refers to the surface area of all triangles sharing the final vertex after vertex i is collapsed. Hence, the edge will be collapsed in the direction that will produce the smallest error value.,三维模型的几何简化,Simplification Fr
4、amework简化框架,最小几何误差 最大几何误差,参考文献,A Study on Collaborative Design Considering Features of Design Tomoyuki Miyashita and Hiroshi Yamakawa ASME Conf. Proc. IDETC/CIE2002 (2002) Volume 2: 28th Design Automation Conference Geometric Simplification to Stream 3D Models for Collaborative Product Design W. D. Li, W. F. Lu, and Y. L. Cai ASME Conf. Proc. IDETC/CIE2005 (2005) Volume 3: 25th Computers and Information in Engineering Conference, Parts A and B,
