Supported by National Key Basic Research Program(2004CB318000);National Natural Science Foundation of China(60573154,61227802 and 61379082)
It is well known that a triangle can be divided by mid-point refinement into four sub-triangles with the same shape. Similarly, a tetrahedron can be parted into eight subtetrahedra, which are generally not uniform in ...
Supported partially by the National Natural Science Foundation of China (Grant Nos. 60673032, 60773179);the National Basic Research Program of China (Grant No. 2004CB318000);the Scientific Starting Foundation of Hangzhou Dianzi University
Spirals are curves with one-signed, monotone increasing or decreasing curvature. They are commonly useful in a variety of applications, either for aesthetic or for engineering requirements. In this paper we propose a ...