http://reply.papertrans.cn/3/243/24258/24258-31.png
http://reply.papertrans.cn/3/243/24258/24258-32.png
Submitted on: 28 January 2000.
Revised on: 06 March 2000.
Accepted on: 23 March 2000.
PERFORMANCE EVALUATION---ELSEVIER
http://reply.papertrans.cn/3/243/24258/24258-34.png
http://reply.papertrans.cn/3/243/24258/24258-35.png
Submitted on: 19 May 2001.
Revised on: 03 June 2001.
Accepted on: 28 June 2001.
PERFORMANCE EVALUATION