1. Department of Systems Design Engineering Seikei University 3‐3‐1 Kichijojikitamachi, Musashino‐shi Tokyo 180–8633 Japan
2. Graduate School of Science and Technology Niigata University 2–8050 Niigata 950–2181 Japan
3. Department of Health Sciences Niigata University School of Medicine 2–746 Asahimachi Niigata 951–8518 Japan