School of Economics and Management, Beijing University of Posts and Telecommunications, Beijing 100876, China;
School of Economics and Management, Beijing University of Posts and Telecommunications, Beijing 100876, China;
School of Economics and Management, Beijing University of Posts and Telecommunications, Beijing 100876, China;
Beijing Key Lab of Intelligent Telecommunication Software and Multimedia, School of Computer Science,Beijing University of Posts and Telecommunications, Beijing 100876, China;