1. College of Artificial Intelligence, North China University of Science and Technology, China
2. Department of Computer Science, University of Sheffield, UK
3. Telecommunications Research Centre (TRC), University of Limerick, Limerick, Ireland
4. Department of Computer Systems, University of Plovdiv “Paisii Hilendarski”, Plovdiv, Bulgaria
5. Institute of Mathematics and Informatics-Bulgarian Academy of Sciences, Sofia, Bulgaria