Li Jinna was born in 1977. She received her B. S. degree of applied mathematics and M. S. degree of applied mathematics from Liaoning University and Northeastern University in 2001 and 2006, respectively. Now she is a Ph. D. candidate at Northeastern University. Her research interests include networked control systems, graph theory and robust control. E-mail: lijinna_721@126.com Zhang Qingling was born in 1956. He received the B. S. and M. S. degrees from the Mathematics Department and the Ph.D. degree from the Automatic Control Department of Northeastern University in 1982, 1986, and 1995, respectively. He is a professor and director for Ph.D. students in Northeastern University. His research interests include descriptor system, robust control and networked control systems.