1. Department of Convergence System Engineering Chungnam National University Daejeon 34134 Republic of Korea
2. Department of Materials Science and Engineering University of Pennsylvania Philadelphia PA 19104 USA
3. Department of Polymer Science and Engineering Pusan National University Busan 46241 Republic of Korea
4. Reliability Assessment Center Korea Research Institute of Chemical Technology Daejeon 34114 Republic of Korea
5. Department of Electrical, Electronics and Communication Engineering Education Chungnam National University Daejeon 34134 Republic of Korea