Abstract
In the complicated design problems, the design variables are large and to search the solutions is difficult. Therefore, a optimization technique without increasing the design variables is desirable. In this paper, such two techniques are proposed for the structural optimization problem as one of the example of the complicated design problems. The first is the method processing the design space in the multi stage, and the second is the method using the quad-trees data structure. The validity of these techniques is made clear to the design problems of continuity structure.
