Liu Yuji is a professor in the School of Mathematics and Statistics, Guangdong University of Finance and Economics, Guangzhou, China. He received his Ph.D. degree from Beijing Institute of Technology, Beijing, China in 2004. From 2003 to 2006, he worked as a Full Professor in the Mathematics Department of Hunan Institute of Technology. His research focuses on functional differential equations, difference equations, time scales and fractional differential equations. He has published more than 60 academic papers in important international journals.