Open access
Submitted: June 3rd, 2011 Published: March 21st, 2012
DOI: 10.5772/37455
From the Edited Volume
Edited by Hongyi Sun
Submitted: June 3rd, 2011 Published: March 21st, 2012
© 2012 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.