1. Department of Industrial Engineering Pusan National University Street No. 63, 2, Geumjeong‐gu Busan 46241 Republic of Korea
2. College of Business Korea Advanced Institute of Science and Technology (KAIST) 85 Hoegi‐ro Dongdaemun‐gu Seoul 02455 Republic of Korea
3. Department of Industrial Engineering and Management Sciences Northwestern University 2145 Sheridan Road, Tech E284 Evanston Illinois 60208‐3109 USA
4. Department of Industrial Engineering Seoul National University 1 Gwanak‐ro Gwanak‐gu Seoul 08826 Republic of Korea