http://reply.papertrans.cn/2/118/11786/11786-31.png
http://reply.papertrans.cn/2/118/11786/11786-32.png
http://reply.papertrans.cn/2/118/11786/11786-33.png
Submitted on: 02 February 2012.
Revised on: 11 March 2012.
Accepted on: 21 March 2012.
___________________IEEE INSTRUMENTATION & MEASUREMENT MAGAZINE
http://reply.papertrans.cn/2/118/11786/11786-35.png
http://reply.papertrans.cn/2/118/11786/11786-36.png