Submitted on: 14 July 2000.
Revised on: 05 August 2000.
Accepted on: 14 September 2000.
___________________APPLIED ARTIFICIAL INTELLIGENCE
http://reply.papertrans.cn/1/22/2148/2148-32.png
http://reply.papertrans.cn/1/22/2148/2148-33.png
Submitted on: 04 December 2007.
Revised on: 19 March 2008.
Accepted on: 06 May 2008.
___________________APPLIED ARTIFICIAL INTELLIGENCE
http://reply.papertrans.cn/1/22/2148/2148-35.png
http://reply.papertrans.cn/1/22/2148/2148-36.png