1. Department of Mechanical Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Gyeongbuk, Pohang 790-784, Republic of Korea
2. Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Gyeongbuk, Pohang 790-784, Republic of Korea