1. Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843-2128, USA
2. Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, P.O. Box 534, SE-75121 Uppsala, Sweden
3. Department of Computer Science, University of Bonn, Germany
4. Fraunhofer IAIS, Schloss Birlinghoven, D-53754 Sankt Augustin, Germany
5. Department of Computer Science, Texas A&M University, College Station, Texas 77843-2128, USA
6. College of Electrical and Information Engineering, Hunan University, Changsha, China
7. Laboratory of Physical and Structural Biology, Program in Physical Biology, NICHD, National Institutes of Health, Bethesda, MD 20892, USA