1. Institute for Cognitive Neurodynamics, School of Science, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, P. R. China
2. School of Information Science and Engineering, East China University of Science and Technology, Meilong 130, Shanghai 200237, P. R. China
3. Research Institute for Electronic Science, Hokkaido University, N12 W7 Kita-ku, Sapporo, Hokkaido, Japan 001-0012, Japan