1. School of Undergraduate Studies, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Techno Jungang-Daero, Hyeonpung-Myeon, Dalseong-Gun, Daegu, 42988, Korea
2. Osaka City University Advanced Mathematical Institute (OCAMI), Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan