1. Course of Information Systems Engineering, National Institute of Technology, Tsuruoka College, 104 Sawada, Inooka, Tsuruoka-city 997-8511, Yamagata, Japan
2. School of Environment and Society, Tokyo Institute of Technology, 2-12-1 Okayama, Meguro, Tokyo 152-8550, Japan
3. School of Data Science, Nagoya City University, 1 Yamanohata, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Aichi, Japan
4. College of Business Administration, Ritsumeikan University, 2-150 Iwakura-cho, Ibaraki-city 567-8570, Osaka, Japan