Institution: | (1) The Institute of Statistical Mathematics, 4-6-7 Minami-Azabu, Minato-ku, 106-8569 Tokyo, Japan;(2) Division of Mathematical Science, Department of Systems Innovation, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, 560-8531 Toyonaka, Osaka, Japan;(3) Present address: Faculty of Economics, Seikei University, Kichijoji-Kitamachi, 180-8633 Musasino, Tokyo, Japan;(4) Present address: Department of Mathematics, Faculty of Engineering, Kansai University, 564-8680 Suita, Osaka, Japan |