Text and Data Mining valid from 2015-06-04
Received: 2 February 2015
Accepted: 21 April 2015
First Online: 4 June 2015
Change Date: 27 August 2015
Change Type: Update
Change Details: The original version of this Article incorrectly named the author Shuxin Han as Sean Han. This has now been corrected in both the PDF and HTML versions of the Article.
: The authors declare no competing financial interests.