Submitted on: 30 September 2014.
Revised on: 20 January 2015.
Accepted on: 13 February 2015.
___________________Acta Technica Napocensis Series-Applied Mathematics Mechanics and Engineering
http://reply.papertrans.cn/1/5/482/482-32.png
Submitted on: 12 June 2007.
Revised on: 18 September 2007.
Accepted on: 18 October 2007.
___________________Acta Technica Napocensis Series-Applied Mathematics Mechanics and Engineering
http://reply.papertrans.cn/1/5/482/482-34.png
Submitted on: 09 March 2013.
Revised on: 21 June 2013.
Accepted on: 14 August 2013.
___________________Acta Technica Napocensis Series-Applied Mathematics Mechanics and Engineering
Submitted on: 20 October 2020.
Revised on: 07 February 2021.
Accepted on: 29 March 2021.
___________________Acta Technica Napocensis Series-Applied Mathematics Mechanics and Engineering