1. a Panel Department , LG Display Company Ltd. , 1007, Deogeun-ri Wollong-myeon, Paju-si , Gyeonggi-do , 413-811 , Korea
2. b Department of Electronics Engineering , Daegu University , Gyeongbuk , 712-714 , Korea
3. c School of Electronic and Electrical Engineering, Kyungpook National University , Korea