1. School of Electrical Engineering, Chungbuk National University; 52 Naesudong-ro Cheongju 361-763 Republic of Korea
2. School of Information and Communication Engineering, Chungbuk National University; 52 Naesudong-ro Cheongju 361-763 Republic of Korea
3. Department of Biomedical Engineering; School of Medicine, Chungbuk National University; 52 Naesudong-ro Cheongju 361-763 Republic of Korea