Abstract :
Copyright and Reprint Permission: Abstracting is permitted with credit to the source. Libraries are permitted to photocopy beyond the limit of US copyright law for private use of patrons those articles in this volume that carry a code at the bottom of the first page, provided the per-copy fee indicated in the code is paid through Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923. For other copying, reprint or republication permission, write to IEEE Copyrights Manager, IEEE Operatons Center, 445 Hoes Lane, P.O.Box 1331, Piscataway, NJ 08855-1331. All rights reserved. Copyright (c) 2007 by the Institute of Electrical and Electronics Engineers.