1. Smart Cities Research Center (Ci2), Instituto Politécnico de Tomar, Campus de Tomar, Tomar, Portugal
2. Department of Social Sciences, College of Science and Technology, Universidade NOVA de Lisboa, Lisbon, Portugal
3. Department of Mathematics and Physics, Instituto Politécnico de Tomar, Tomar, Portugal
4. Mathematics, King Abdulaziz University, Jeddah, Egypt