Article history: Received 19 August 2014 Received in revised form 19 September 2014 Accepted 29 September 2014 Available online 3 November 2014

Article history: Received 8 August 2014 Received in revised form 12 September 2014 Accepted 25 September 2014 Available online 2 November 2014

Article history: Received 29 June 2014 Received in revised form 22 November 2014 Accepted 2 December 2014 Available online 5 December 2014 Editor: M. Doser

Article history: Received 15 April 2014 Received in revised form 29 September 2014 Accepted 28 October 2014 Available online 4 November 2014

Article history: Received 29 June 2014 Received in revised form 22 November 2014 Accepted 2 December 2014 Available online 5 December 2014 Editor: M. Doser

Article history: Received 19 February 2014 Received in revised form 28 October 2014 Accepted 28 October 2014 Available online 4 November 2014

Article history: Received 10 March 2014 Received in revised form 12 November 2014 Accepted 1 December 2014 Available online 9 December 2014

Article history: Received 19 August 2014 Received in revised form 19 September 2014 Accepted 29 November 2014 Available online 15 December 2014

Article history: Received 24 April 2014 Received in revised form 14 September 2014 Accepted 23 November 2014 Available online 3 December 2014

Article history: Received 3 August 2014 Received in revised form 27 September 2014 Accepted 24 October 2014 Available online 3 November 2014