中文摘要：

Xiong Fu received his BS and PhD in computer science from the University of Science and Technology of China, China, in 2002 and 2007, respectively. He is currently an associate profes- sor in computer science at the Nanjing University of Posts ＆ Telecommunica- tions, China. His research interests in-clude parallel and distributed computing, and cloud computing.E-mail： fux @njupt.edu.cn Chen Zhou received her BS in com- puter science from the Nantong Univer- sity, Nantong, in 2013. She is a mas- ter candidate at Nanjing University of Posts ＆ Telecommunications, China. Her research interests include cloud computing, and computer networks.