1. Department of Mathematics and Computer Science; Kagoshima University Graduate School of Science and Technology; Kagoshima Japan
2. Department of Data Science; National Cerebral and Cardiovascular Center; Saita Japan
3. Department of Biostatistics and Center for Biostatistics in AIDS Research; Harvard T.H. Chan School of Public Health; Boston MA U.S.A
4. Department of Information and Computer Technology, Faculty of Engineering; Tokyo University of Science; Tokyo Japan