1、 references:
https://blog.csdn.net/hjimce/article/details/50187029
https://www.computer.org/csdl/proceedings/cvpr/2014/5118/00/5118a580-abs.html
http://www.cnblogs.com/edwardbi/p/5647522.html
2、some details for improvement
a)when training svms,batch is not made from 32 Positive and 96 Negative