1. Division of Business Administration, Hanyang University, 171 Sa 3-dong Sangrok-gu, Ansan 426-791, Republic of Korea.
2. Ajou University, College of Social Science, San 5, Wongcheon-dong, Yeongtong-gu, Suwon, Korea 443-749.
3. (Corresponding Author) Division of Business Administration, Hanyang University, 171 Sa 3-dong Sangrok-gu, Ansan 426-791, Republic of Korea.