zhaoqingpan@nuist.edu.cn
leegend_chen@outlook.com
wenjieyan@scse.hebut.edu.cn
© 2015 Zhaoqing Pan, Liming Chen, Wenjie Yan, published by Bulgarian Academy of Sciences, Institute of Information and Communication TechnologiesThis work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.