HONG MIN, YOO-KUN CHO AND JI-MAN HONG+
School of Computer Science and Engineering
Seoul National University
Gwanak-gu, Seoul, 151-742 Korea
E-mail: {hmin; ykcho}@os.snu.ac.kr
+School of Computing
Soongsil University
Dongjak-gu, Seoul, 156-743 Korea
E-mail: jiman@ssu.ac.kr