Affiliation: | 1.School of Liberal Arts, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul, 01811, Republic of Korea ;2.Department of Mathematical Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-Gu, Seoul, 08826, Republic of Korea ;3.Department of Mathematics, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul, 06978, Republic of Korea ;4.Department of Mathematics Education, Kyungnam University, Changwon-si, Gyeongsangnam-do, 51767, Republic of Korea ; |