1. Department of Robotics, Ritsumeikan University, Shiga, Japan
2. Information Engineering College, Zhejiang University of Technology, Hangzhou, People's Republic of China
3. Synthetic Chemicals Laboratory, R & D Center, Mitsui Chemicals, Inc., Chiba, Japan
4. Research Organization of Science and Technology, Ritsumeikan University, Shiga, Japan
5. Electrical Engineering Department, Graduate School of Science and Engineering, Kansai University, Osaka, Japan