Acknowledgments
This work was partly supported by National Natural Science Foundation of China (Grant Nos. 11801559, 12031005).
Disclosure statement
No potential conflict of interest was reported by the author(s).
Additional information
Funding
Notes on contributors
Wei Ma
Wei Ma is Assistant Professor at Institute of Statistics and Big Data, Renmin University of China.
Li-Xin Zhang
Li-Xin Zhang is Professor at School of Mathematical Sciences, Zhejiang University.
Feifang Hu
Feifang Hu is Professor at Department of Statistics, George Washington University.