Mio Kobayashi [ Department of Materials Engineering, National Institute of Technology, Nagaoka College, 888 Nishikatagai, Nagaoka, Niigata 940-8532, Japan ]
Shunya Hayashi [ Department of Materials Engineering, National Institute of Technology, Nagaoka College, 888 Nishikatagai, Nagaoka, Niigata 940-8532, Japan ]
Yuji Tasaki [ Department of Materials Engineering, National Institute of Technology, Nagaoka College, 888 Nishikatagai, Nagaoka, Niigata 940-8532, Japan ]