[1] corresponding author = producer (a owner of the paper: denoted by * & email on the coverpage)
[2] co-corresponding authors (denoted by * & emails on the coverpage)
[3] 1st author = director
[4] co-1st authors (denoted by "equally contribute" in the coverpage)
w/kahng : co-1st authors & co-corresponding authors
w/jjang: single 1st author & co-corresponding authors
