http://reply.papertrans.cn/2/134/13367/13367-31.png
Submitted on: 14 January 2012.
Revised on: 06 April 2012.
Accepted on: 26 May 2012.
___________________INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
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Submitted on: 07 December 2012.
Revised on: 26 March 2013.
Accepted on: 24 April 2013.
___________________INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
http://reply.papertrans.cn/2/134/13367/13367-35.png
http://reply.papertrans.cn/2/134/13367/13367-36.png