阮幼林:To whom correspondence should be addressed. E-mail: manyl@126.com. Ruan Youlin, born in 1972. He received his Ph.D degree from Department of Computer Science of Huazhong University of Science and Technology in 2004. He also received his B.S. and M.S. degrees from Wuhan University in 1994 and 2001 respectively. Now, he is a visiting researcher of State Key Laboratory for Novel Software Technology of Nanjing University. His research interests include parallel computing, real time systems, design and optimization of algorithm.