1. Institute of Electronic Materials, High-Tech and Development Centre, Kim Il Sung University, PO Box 76, Pyongyang, Democratic People's Republic of Korea
2. Computational Materials Design (CMD), Faculty of Materials Science, Kim Il Sung University, PO Box 76, Pyongyang, Democratic People's Republic of Korea
3. Physics Department, O Jung Hub Chongjin University of Education, Chongjin, Hamgyong North Province, Democratic People's Republic of Korea