[Zheng, Kexin;Lv, Shaohe;Ma, Fang;Chen, Fei;Dou, Yong] Natl Univ Def Technol, Natl Lab Parallel & Distributed Proc, 109 Deya Rd, Changsha 410073, Hunan, Peoples R China.^[Jin, Chi] Univ South China, Sch Comp Sci & Technol, Changsha 410012, Hunan, Peoples R China.