Submitted on: 30 May 2001.
Revised on: 20 July 2001.
Accepted on: 29 August 2001.
___________________IEEE TRANSACTIONS ON EDUCATION
Submitted on: 15 February 1999.
Revised on: 19 March 1999.
Accepted on: 10 April 1999.
___________________IEEE TRANSACTIONS ON EDUCATION
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http://reply.papertrans.cn/2/120/11970/11970-25.png
Submitted on: 13 October 2017.
Revised on: 11 November 2017.
Accepted on: 04 December 2017.
___________________IEEE TRANSACTIONS ON EDUCATION
Submitted on: 19 April 2020.
Revised on: 04 June 2020.
Accepted on: 12 July 2020.
___________________IEEE TRANSACTIONS ON EDUCATION
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Submitted on: 15 May 2009.
Revised on: 06 July 2009.
Accepted on: 14 August 2009.
___________________IEEE TRANSACTIONS ON EDUCATION