1. Department of Mechanical Engineering, Graduate School of Engineering Science, Yokohama National University, Yokohama, Kanagawa, Japan
2. Department of System Innovation, Osaka University, Toyonaka, Osaka, Japan
3. Department of Control and System Engineering, Tokyo Institute of Technology, Meguro, Tokyo, Japan
4. Department of Electrical Engineering and Information Science, National Institute of Technology, Kure College, Kure, Hiroshima, Japan
5. Division of Systems Research Faculty of Engineering, Yokohama National University, Yokohama, Kanagawa, Japan