Submitted on: 08 October 2008.
Revised on: 20 December 2008.
Accepted on: 01 February 2009.
___________________JOURNAL OF THE KOREAN MATHEMATICAL SOCIETY
Submitted on: 12 December 2007.
Revised on: 09 March 2008.
Accepted on: 19 March 2008.
___________________JOURNAL OF THE KOREAN MATHEMATICAL SOCIETY
http://reply.papertrans.cn/2/198/19783/19783-23.png
http://reply.papertrans.cn/2/198/19783/19783-24.png
http://reply.papertrans.cn/2/198/19783/19783-25.png
Submitted on: 14 September 2002.
Revised on: 29 November 2002.
Accepted on: 27 January 2003.
___________________JOURNAL OF THE KOREAN MATHEMATICAL SOCIETY
http://reply.papertrans.cn/2/198/19783/19783-27.png
Submitted on: 23 November 1999.
Revised on: 18 January 2000.
Accepted on: 11 February 2000.
___________________JOURNAL OF THE KOREAN MATHEMATICAL SOCIETY
http://reply.papertrans.cn/2/198/19783/19783-29.png
Submitted on: 24 June 2012.
Revised on: 06 August 2012.
Accepted on: 14 September 2012.
___________________JOURNAL OF THE KOREAN MATHEMATICAL SOCIETY