1. Institute for Datability Science, Osaka University, 13013 Suita, Osaka, Japan, (e-mail: trung@am.sanken.osaka-u.ac.jp)
2. Institute for Datability Science, Osaka University, 13013 Suita, Osaka, Japan, (e-mail: nagahara@ids.osaka-u.ac.jp)
3. Department of Advanced information Technology, Kyushu Daigaku, 12923 Fukuoka, Fukuoka, Japan, (e-mail: rin@kyudai.jp)