基于单调链法的凸壳三角剖分算法研究

在分析应用相关定义的基础上，该文提出了一种基于单调链法的凸壳三角剖分方法。这种算法的计算复杂度优于标准的Delaunay算法，有效性也比许多凸多边形算法要突出，是一种行之有效的快速算法。将它用于网格重新剖分处理，在矢量图形网格的简化、优化、压缩以及传输中都具有现实的应用意义。     

Genetic Algorithms to the Nesting Problem in the Leather Manufacturing Industry

The nesting problem in the leather manufacturing is the problem of placing a set of irregularly shaped pieces (called stencils) on a set of irregularly shaped surfaces (called leathers sheets). This paper presents a novel and promising processing approach. After the profile of leather sheets and stencils is obtained with digitizer, the discretization makes the processing independent of the specific geometrical information. The constraints of profile are regarded thoroughly. A heuristic bottom-left placement strategy is employed to sequentially locate stencils on sheets. The optimal placement sequence and rotation are deterimined by genetic algorithms (GA). A natural concise encoding method is developed to satisfy all the possible requirements of the leather nesting problem. The experimental results show that the proposed algorithm can not only be applied to the normal two-dimensional nesting problem, but also especially suitable for the placement of multiple twodimensional irregular stencils on multiple two-dimensional irregular sheets.     

Multi-strategies in Case Based Design Knowledge Management on Web

Design knowledge management is very important toimprove the design process performance. The casebased design (CBD) is a methodology to followmankind's problem solving strategy, one of its aims isto realize the design knowledge reuse. This methodhas been used in many fields, but there are still somedifficulties that hindered its application. The first isabout the difficulty in the formalization of a designcase, especially representation of some experiencesthat was the weakness in former researches. The     

新公差概念的探讨

机件的尺寸精度和几何精度是保证机件功能要求及互换性的关键因素。如何控制机件的这两种精度,本文提出了两种控制方法:边界控制法——综合控制和独立控制法——分别控制,并对此作了详细的分析。尤其是对状态、尺寸、边界三者及其相互关系发表了新的观点。文章最后以表格的形式对两种控制方法的差异和经济效益作了分析比较。     

Human Body Modeling and Posture Simulating Based on 3D Surface Scan Data

This paper presents a new approach for modeling the human body by considering the motion state and the shape of whole body. The body model consists of a skeleton kinematic model and a surface model. The former is used to determine the posture of the body, and the latter is used to generate the body shape according to the given posture. The body surface is reconstructed with multi-segment B-spline surfaces based on the 3D scan data from a real human body. Using only a few joints parameters and the original surface scan data, the various body postures and the shape can be generated easily. The model has a strong potential of being used for ergonomic design, garment design, virtual reality environment, as well as creating human animation, etc.