JUN-SANG PARK1, SUNG-HO YOON1, SU-KANG LEE1, YOUNGJOON WON2 AND MYUNG-SUP KIM1,+
1Department of Computer and Information Science
Korea University
Sejong, 30019 Korea
E-mail: {junsang_park; sungho_yoon; sukanglee; tmskim}@korea.ac.kr
2Department of Information System
Hanyang University
Seoul, 04763 Korea
E-mail: youngjoon@hanyang.ac.kr