About the Authors

Hui Wang
Chen Chen
Hsieh Fushing


Affiliation Department of Statistics, University of California Davis, Davis, California, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: HF. Performed the experiments: HF HW CC. Analyzed the data: HF HW CC. Wrote the paper: HF HW CC.