1. Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
2. Department of Mathematical and Material Sciences, Faculty of Integrated Arts and Sciences, The University of Tokushima, Minamijosanjima, Tokushima 770-8502, Japan
3. SPring-8, Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198, Japan
4. Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan