1. Quality and Reliability Laboratory, Daewoo Electronics Co., Ltd., #412-2, Cheongcheon 2-Dong, Pupyong-Ku, Incheon, South Korea
2. Quality and Reliability Laboratory, Daewoo Electronics Co., Ltd., South Korea
3. Department of Industrial Information Engineering, The University of Suwon, San 2-2, South Korea
4. Department of Industrial Information System Engineering, Ajou University, San 5, South Korea