About the Authors

Yan-Ming Lai

Affiliation Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan, 10617, R.O.C.

Pu-Jen Cheng

Affiliation Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan, 10617, R.O.C.

Cheng-Chi Lee

cclee@mail.fju.edu.tw

Affiliations Department of Library and Information Science, Fu Jen Catholic University, New Taipei, Taiwan, 24205, R.O.C., Department of Photonics and Communication Engineering, Asia University, Taichung, Taiwan 413, R.O.C.

Chia-Yi Ku

Affiliation Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan, 10617, R.O.C.

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: YML PJC CCL CYK. Performed the experiments: YML PJC CCL CYK. Analyzed the data: YML PJC CCL CYK. Contributed reagents/materials/analysis tools: YML PJC CCL CYK. Wrote the paper: YML PJC CCL CYK.