IG-HOON LEE1,3, SANG-GOO LEE1 AND JUNHO SHIM2,+
1School of Computer Science and Engineering
Seoul National University
Seoul, 151-742 Korea
E-mail: {ihlee; sglee}@europa.snu.ac.kr
2Department of Computer Science
Sookmyung Women’s University
Seoul, 140-742 Korea
E-mail: jshim@sookmyung.ac.kr