Authors
Toshihiro Ashino
Dept of Regional Development Studies, TOYO University, 1-1-1 Izumino, Itakura-machi, Ohra-gun, Gunma 374-0193 Japan
Nobuto Oka
Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 Japan
