1. Graduate School of Public Policy and Information Technology, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea
2. Department of Computer Engineering, Inje University, Gimhae 50834, Republic of Korea
3. Department of Software, Soongsil University, Seoul 07027, Republic of Korea
4. ITM Division, Department of Industrial Engineering, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea