1. 2) Ministry of the Environment: http://www.env.go.jp/recycle/circul/pamph/fig/e-guide.pdf, (accessed April 22, 2005)
2. 4) M. Kiuchi: Proc. of The 1st Symp. on PROTEUS Project, NEDO, Tokyo, Japan, (2004), 1.
3. 5) J. Ikeda and S. Inagaki: Proc. of The 1st Symp. on PROTEUS Project, NEDO, Tokyo, Japan, (2004), 21.