FIRST, Aihara Innovative Mathematical Modelling Project, JST, Kawaguchi, Japan. katori@sat.t.u-tokyo.ac.jp|FIRST, Aihara Innovative Mathematical Modelling Project, JST, Kawaguchi, Japan. katori@sat.t.u-tokyo.ac.jp|FIRST, Aihara Innovative Mathematical Modelling Project, JST, Kawaguchi, Japan. katori@sat.t.u-tokyo.ac.jp|FIRST, Aihara Innovative Mathematical Modelling Project, JST, Kawaguchi, Japan. katori@sat.t.u-tokyo.ac.jp|FIRST, Aihara Innovative Mathematical Modelling Project, JST, Kawaguchi, Japan. katori@sat.t.u-tokyo.ac.jp|FIRST, Aihara Innovative Mathematical Modelling Project, JST, Kawaguchi, Japan. katori@sat.t.u-tokyo.ac.jp