1. Cyber-Physical Engineering Informatics Research Core (Cypher), Okayama University, Okayama 700-8530, Japan
2. Center for Advanced Intelligence Project, RIKEN, Chuo, Tokyo 103-0027, Japan
3. National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
4. Kyoto University Institute for Advanced Study, WPI-ASHBi, Kyoto University, Sakyo, Kyoto 606-8501, Japan