Manuscript received August 17, 2018; revised February 1, 2019; accepted March 4, 2019. Date of publication March 25, 2019; date of current version June 6, 2019. This work was supported in part by the National Natural Science Foundation of China under Grant 61503128, in part by the Science and Technology Plan Project of Hunan Province under Grant 2016TP1020, in part by the Scientific Research Fund of Hunan Provincial Education Department under Grant 16C0226 and Grant 18A333, in part by the Hengyang Guided Science and Technology Projects and Application-Oriented Special Disciplines under Grant Hengkefa [2018]60-31, in part by the Double First-Class University Project of Hunan Province under Grant Xiangjiaotong [2018]469, in part by the Hunan Province Special Funds of Central Government for Guiding Local Science and Technology Development under Grant 2018CT5001, and in part by the Subject Group Construction Project of Hengyang Normal University under Grant 18XKQ02. Recommended for publication by Associate Editor X. Fan upon evaluation of reviewers’ comments. (Corresponding author: Hui-Huang Zhao.) H.-H. Zhao is with the Department of Computer Science, College of Computer Science and Technology, Hengyang Normal University, Hengyang 421002, China (e-mail: happyday.huihuang@gmail.com).
