1. Department of Mechanical and System Design Engineering Hongik University Seoul 04066 Republic of Korea
2. Strategic Technology Research Institute Korea Research Institute of Standards and Science Daejeon 34113 Republic of Korea
3. School of Electrical and Computer Engineering Purdue University West Lafayette IN 47907 USA
4. Optical Lens Materials Research Center Korea Photonics Technology Institute Gwangju 61007 Republic of Korea
5. Department of Electronic Engineering Jeonbuk National University Jeonju 54896 Republic of Korea
6. School of Mechanical Engineering Yonsei University Seoul 03722 Republic of Korea