A technique report, arXiv preprint ***Tong Wu**, [Xuefei Ning](https://nicsefc.ee.tsinghua.edu.cn/people/xuefei-ning/), [Wenshuo Li](https://nicsefc.ee.tsinghua.edu.cn/people/wilson-lee/), [Ranran Huang](https://nicsefc.ee.tsinghua.edu.cn/people/ranran-huang/), [Huazhong Yang](https://scholar.google.com/citations?user=3m8I0XAAAAAJ&hl=en), [Yu Wang](http://nicsefc.ee.tsinghua.edu.cn/people/yu-wang/)*
A technique report, my first undergraduate research project. ***Tong Wu**, [Jiansheng Chen](https://jschenthu.weebly.com/), [Yiqing Huang](https://scholar.google.com.hk/citations?user=MGMKjMoAAAAJ&hl=zh-CN), [Yu Wang](http://nicsefc.ee.tsinghua.edu.cn/people/yu-wang/)*