1. Department of Computer Science and Information Engineering, Asia University, Taichung, Taiwan
2. Center for Distributed and Mobile Computing, University of Cincinnati, Cincinnati, OH, USA
3. Department of Computer Science, Digital Image Processing Laboratory, Islamia College Peshawar, Peshawar, Pakistan
4. School of Computing, Macquarie University, Sydney, NSW, Australia
5. TECNALIA, Basque Research and Technology Alliance (BRTA), Derio, Spain