Masayuki Matsumoto Tadao Tsurumaki Satoru Kitamura Dai Watanabe Kinji Mori Assurance Evaluation Technology of Train Control System for Achieving Expansion during Operation . 71-78 2002 conf/hase/2002 HASE http://doi.ieeecomputersociety.org/10.1109/HASE.2002.1173105 db/conf/hase/hase2002.html#MatsumotoTKWM02