Hyung-Do Choi received his MS and Ph.D. degrees in material science from Korea University, Seoul, Rep. of Korea, in 1989 and 1996, respectively. Since 1997, he has been with the Electronics and Telecommunications Research Institute, Rep. of Korea. He has performed research on the biological effects of RF radiation and has developed RF radiation protection standards and regulations. His current research interests include spectrum management, microwave tomography, and EMC countermeasures.