Robert Chandler Chiou Peng Lam Huaizhong Li AD2US: An Automated Approach to Generating Usage Scenarios from UML Activity Diagrams. 9-16 2005 conf/apsec/2005 APSEC http://doi.ieeecomputersociety.org/10.1109/APSEC.2005.25 db/conf/apsec/apsec2005.html#ChandlerLL05