1. School of Materials Science, JAIST, Asahidai 1-1, Nomi, Ishikawa 923-1292, Japan
2. International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste, Italy
3. Research Center for Advanced Computing Infrastructure, JAIST, Asahidai 1-1, Nomi, Ishikawa 923-1292, Japan
4. School of Information Science, JAIST, Asahidai 1-1, Nomi, Ishikawa 923-1292, Japan