Meikang Qiu Jing Deng Edwin Hsing-Mean Sha Failure Rate Minimization with Multiple Function Unit Scheduling for Heterogeneous WSNs. 5213-5217 2008 GLOBECOM http://dx.doi.org/10.1109/GLOCOM.2008.ECP.996 conf/globecom/2008 db/conf/globecom/globecom2008.html#QiuDS08