1. School of Computer Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia
2. Faculty of Computer and Information Technology, University of Shabwah, Shabwah, Yemen
3. Grupo de Tecnología del Habla y Aprendizaje Automático (THAU Group), Information Processing and Telecommunications Center, E.T.S.I. de Telecomunicación, Universidad Politécnica de Madrid, Madrid, Spain
4. Department of Network and Computer Security, State University of New York Polytechnic Institute, Utica, NY, USA