© The Author(s) (Published by EDP Open) Posted on April 16, 2014 by SCG DR Copyright Holders: © The Author(s) (Published by EDP Open) a Self-archiving policy Conditions Accepted version: √ Open Access Journal Published version: √ Open Access Journal Remarks: Copyright on any article in the [journal] is retained by the author(s) under the Creative Commons license, which permits unrestricted use, distribution, and reproduction provided the original work is properly cited. Verification Date: 04.04.2014
