Professor Na joined Xian Jiaotong University, China, in 2018 as a Foreign Expert to work in the field of simulation and optimization of arc, laser and laser arc hybrid welding process, in which the arc physics and multiple reflections in keyhole are linked with the weld pool dynamics and also with the metallurgical and mechanical design of thermal processed structures. Recently his research field has been extended to additive manufacturing such as Wire Arc Additive Manufacturing, Laser Metal Deposition and Selective Laser Melting. Professor Na graduated from Seoul National University for B.Sc., from KAIST for M.Sc. in Korea, and has got Dr.-Ing. Degree from IFS of TU Braunschweig, Germany in 1983. Since then he was working at KAIST, Korea until 2017. He was also working at various prestigious institutions such as BIAS and BAM in Germany, VTT in Finland and University of Woolongong in Australia as an international expert invited by Humboldt Foundation, Tekes and Australian Research Council respectively. He has published more than 300 peer-reviewed journal papers, more than 270 conference presentations including 7 plenary, 9 keynote and 16 invited speeches, and has registered 24 patents in Korea. Professor Na served as the President of Korean Welding and Joining Society and President of Asian Welding Federation, and was appointed Academician of Korean Academy of Science and Technology, Fellow of American Welding Society and Fellow of International Institute of Welding.