1. Department of Info.Sys.Eng., Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan
2. International Young Researcher Empowerment Center, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
3. Department of Media Architecture, 116-2 Kamedanakano, Hakodate, Hokkaido 041-8655, Japan
4. Graduate School of Infomation Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0814, Japan