作者机构:[1]Department of Computer Science, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA, [2]Department of Computer Science and Technology, Ocean University of China, Qingdao 266100, P. R. China
相关基金:The work of Y. Wang was supported in part by the US National Science Foundation (NSF) under Grant Nos. CNS-0721666, CNS-0915331, and CNS-1050398. The work of Y. Liu was partially supported by the National Natural Science Foundation of China (NSFC) under Grant No. 61074092 and by the Shandong Provincial Natural Science Foundation, China under Grant No. Q2008E01. The work of Z. Guo was partially supported by the NSFC under Grant Nos. 61170258 and 6093301. This work was partially done when Y. Liu visited the De- partment of Computer Science, University of North Caro- lina at Charlotte, with a scholarship from the China Scholarship Council.