Submitted on: 27 March 2002.
Revised on: 25 April 2002.
Accepted on: 21 June 2002.
___________________ACM Transactions on the Web---ASSOC COMPUTING MACHINERY
Submitted on: 27 October 2022.
Revised on: 31 January 2023.
Accepted on: 14 March 2023.
___________________ACM Transactions on the Web---ASSOC COMPUTING MACHINERY
Submitted on: 06 April 2008.
Revised on: 09 June 2008.
Accepted on: 07 July 2008.
___________________ACM Transactions on the Web---ASSOC COMPUTING MACHINERY
Submitted on: 01 December 2015.
Revised on: 07 January 2016.
Accepted on: 04 February 2016.
___________________ACM Transactions on the Web---ASSOC COMPUTING MACHINERY
Submitted on: 14 February 2001.
Revised on: 04 April 2001.
Accepted on: 26 April 2001.
___________________ACM Transactions on the Web---ASSOC COMPUTING MACHINERY
http://reply.papertrans.cn/1/2/173/173-26.png
http://reply.papertrans.cn/1/2/173/173-27.png
http://reply.papertrans.cn/1/2/173/173-28.png
http://reply.papertrans.cn/1/2/173/173-29.png
Submitted on: 30 January 2006.
Revised on: 01 April 2006.
Accepted on: 04 May 2006.
___________________ACM Transactions on the Web---ASSOC COMPUTING MACHINERY