First Author:   Hiromasa Takahashi Faculty of International Studies, Hiroshima City University htaka@intl.hiroshima-cu.ac.jp         Second Author: Akihiro Suzuki Faculty of Literature and Social Sciences, Yamagata University asuzuki@human.kj.yamagata-u.ac.jp         Third Author: Toru Takemoto Faculty of Economics, Meikai University takemoto@meikai.ac.jp