http://reply.papertrans.cn/3/293/29245/29245-31.png
Submitted on: 19 October 2014.
Revised on: 28 November 2014.
Accepted on: 12 December 2014.
NULL
Submitted on: 20 October 2004.
Revised on: 15 November 2004.
Accepted on: 25 November 2004.
NULL
http://reply.papertrans.cn/3/293/29245/29245-34.png
http://reply.papertrans.cn/3/293/29245/29245-35.png
Submitted on: 13 April 2009.
Revised on: 15 May 2009.
Accepted on: 30 May 2009.
TechTrends---SPRINGER INT PUBL AG