1. Division of Mechanical Systems, Department of Mechanical and Systems Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2201, Japan
2. Associate Professor Division of Mechanical Systems, Department of Mechanical and Systems Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2201, Japan; JST PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan e-mail:
3. The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan