1. Department of Automation; Shanghai Jiao Tong University; 2-509, SEIEE Buildings, 800 Dongchuan, RD. Shanghai CN 200240
2. Department of Mechanical and Aerospace Engineering; Tokyo Institute of Technology; Ishikawadai 1st bldg, 2-12-1 I1-52, Ohokayama Meguro-ku Tokyo, JP 152-8552