Zhengwei Qi Liang Liu Fuyuan Zhang Haibing Guan Hao Wang Ying Chen 171-178 2009 SERVICES I http://doi.ieeecomputersociety.org/10.1109/SERVICES-I.2009.61 conf/services/2009-1 db/conf/services/services2009-1.html#QiLZGWC09