1. Department of Systems Science, Graduate School of System Informatics, Kobe University, Rokkodai 1-1, Nada, Kobe 657-8501, Japan
2. Center of Optical Scattering Image Science, Kobe University, Rokkodai 1-1, Nada, Kobe 657-8501, Japan
3. Department of Applied Bioscience, Kanagawa Institute of Technology, Atsugi 243-0292, Japan