1. Chonnam National University Medical School, Hwasun, Korea.
2. Department of Preventive Medicine, Chonnam National University Medical School, Hwasun, Korea.
3. Department of Preventive Medicine & Institute of Wonkwang Medical Science, Wonkwang University School of Medicine, Iksan, Korea.
4. Department of Preventive Medicine, Chosun University Medical School, Gwangju, Korea.
5. Department of Preventive Medicine, Chungnam National University Medical School, Daejeon, Korea.