1. Faculty of Engineering and Carbon Institute of Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano-shi 380-8553, Japan
2. Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Chudong-ro 92, Bongdong-eup, Wanju-gun, Jeonbuk 565-905, Republic of Korea
3. School of Polymer Science and Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, Republic of Korea