1. Department of Energy and Environment Science, Nagaoka University of Technology, Nagaoka 940-2188, Japan
2. Department of Electrical, Electronics and Information Engineering, Nagaoka University of Technology, Nagaoka 940-2188, Japan
3. Department of Materials Science and Technology, Nagaoka University of Technology, Nagaoka 940-2188, Japan
4. Department of Nuclear System Safety Engineering, Nagaoka University of Technology, Nagaoka 940-2188, Japan