Funding for this research was provided by:
National Natural Science Foundation of China (61272273)
Nanjing University of Posts and Telecommunications (XJKY14016, NY217009)
Education Department of Jiangxi Province (GJJ151076)
National Natural Science Foundation of China (61702280)
Article History
Received: 31 August 2017
Accepted: 25 January 2018
First Online: 13 February 2018