First Author:   Vatthanamixay Chansomphou Graduate School for Internatinal Development and Cooperation, Hiroshima University vatthanamixay@hiroshima-u.ac.jp   1-5-1 Kagamiyama Higashi-Hiroshima, 739-8529, Japan       Second Author: Masaru Ichihashi Graduate School for Internatinal Development and Cooperation, Hiroshima University ichi@hiroshima-u.ac.jp   1-5-1 Kagamiyama Higashi-Hiroshima, 739-8529, Japan