Acknowledgements

The LAPACK library, <URL:http://www.netlib.org/lapack/>, was used for solving the eigenvalue problems and the GFD-DENNOU library, <URL:http://www.gfd-dennou.org/index.html.en>, was used for drawing the figures. This manuscript was made by the following tools for document translator:

• RDtool Version 0.6.20 (November 6, 2005) Copyright 2004, 2005, Ruby's., <URL:http://raa.ruby-lang.org/project/rdtool>
• RTtool Version 1.0.1 (October 28, 2005) Copyright 2005, Ruby's., <URL:http://raa.ruby-lang.org/project/rttool/>

Acknowledgements