Submitted on: 05 October 2006.
Revised on: 11 November 2006.
Accepted on: 05 December 2006.
___________________DESIGN ISSUES---MIT PRESS
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Submitted on: 02 January 2000.
Revised on: 30 January 2000.
Accepted on: 16 February 2000.
___________________DESIGN ISSUES---MIT PRESS
http://reply.papertrans.cn/1/74/7310/7310-34.png
http://reply.papertrans.cn/1/74/7310/7310-35.png
Submitted on: 15 March 2016.
Revised on: 01 May 2016.
Accepted on: 20 May 2016.
___________________DESIGN ISSUES---MIT PRESS