1. Graduate School of Sciences and Humanities, Nara Women’s University, Nara 630-8506, Japan
2. Department of Systems Science, Graduate School of Informatics, Kyoto University, Kyoto 606-8501, Japan
3. Department of Mathematical and Computing Science, Tokyo Institute of Technology, Meguro, Tokyo 152-8550, Japan
4. Institute for Physics of Intelligence & Department of Physics, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan