He received his B.S., M.S. and Ph.D. degree in electrical engineering and computer science from the Korea Advanced Institute of Science and Technology (KAIST) in 1999,2001 and 2007 respectively. Previously he worked at University of California, Irvine as a post doctoral researcher. His research interests include operating system, distributed system, world wide web, peer-to-peer algorithm/network, overlay multicast and online social network. He is a member of IEEE, USENIX, and IEICE.