1. Department of Mechanical Engineering and Intelligent Systems, The University of Electro-Communications (UEC), 1-5-1 Chofugaoka, Chofu-shi, Tokyo 182-8585, Japan,
2. Department of Mechanical Design Engineering, Hanbat National University, San 16-1, Duckmyoung-Dong, Yuseong-Gu, Daejeon 305-719, Korea
3. Department of Mechanical Engineering and Intelligent Systems, The University of Electro-Communications (UEC), 1-5-1 Chofugaoka, Chofu-shi, Tokyo 182-8585, Japan