Department of Statistics, Nanjing University of Finance and Economics, Nanjing, China.|School of Statistics and Mathematics, Zhongnan University of Economics and Law, Wuhan, China.|School of Statistics and Management, Shanghai University of Finance and Economics, Shanghai, China.|Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore.|Department of Mathematics, Hong Kong University of Science and Technology, Hong Kong.|Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore.|Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore.