1. Department of Applied Science for Electronics and Materials, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
2. Department of Control and Information Systems Engineering, National Institute of Technology, Kurume College, Kurume, Fukuoka 830-8555, Japan
3. Department of Basic Sciences, Faculty of Engineering, Kyushu Institute of Technology, Kitakyushu, Fukuoka 804-8550, Japan