Open access
Submitted: 15 December 2011 Published: 03 April 2013
DOI: 10.5772/51877
From the Edited Volume
Edited by Francisco Manuel Braz Fernandes
Submitted: 15 December 2011 Published: 03 April 2013
© 2013 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.