1. Department of Preventive Medicine, Graduate School Kyung Hee University Seoul Korea
2. Department of Occupational and Environmental Medicine Kyung Hee University Hostpital Seoul Korea
3. Informatization Department Ewha Womans University Seoul Hospital Seoul Korea
4. Department of Internal Medicine Veterans Healthcare Service Medical Center Seoul Korea
5. Department of Family Medicine, College of Medicine Ewha Womans University Seoul Korea
6. Department of Occupational and Environment Medicine, College of Medicine Ewha Womans University Seoul Korea
7. Department of Anesthesiology and Pain Medicine Kyung Hee University Medical Center Seoul Korea
8. Department of Occupational and Environmental Medicine, School of Medicine Kyung Hee University Seoul Korea