Shuzo Murakami (Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohokuku, Yokohama 223-8522 Japan), Shinsuke Kato (Institute of Industrial Science, The University of Tokyo, Tokyo, Japan), Ryozo Ooka (Institute of Industrial Science, The University of Tokyo, Tokyo, Japan) and Yasuyuki Shiraishi (Faculty of Environmental Engineering, The University of Kitakyushu, Kitakyushu, Japan)
