Submitted on: 07 March 2013.
Revised on: 17 April 2013.
Accepted on: 08 June 2013.
___________________INTERNATIONAL REGIONAL SCIENCE REVIEW
http://reply.papertrans.cn/2/144/14375/14375-32.png
Submitted on: 20 January 2015.
Revised on: 23 February 2015.
Accepted on: 23 April 2015.
___________________INTERNATIONAL REGIONAL SCIENCE REVIEW
http://reply.papertrans.cn/2/144/14375/14375-34.png
http://reply.papertrans.cn/2/144/14375/14375-35.png
Submitted on: 21 June 2013.
Revised on: 19 October 2013.
Accepted on: 21 November 2013.
___________________INTERNATIONAL REGIONAL SCIENCE REVIEW