1. Hangzhou Dianzi University, School of Mechanical Engineering, Er Hao Da Jie 1158, Xiasha, Hangzhou 310018, China
2. Center for Applied Mathematics and Bioinformatics, Gulf University for Science and Technology, West Mishref 32093, Kuwait
3. Section of Mathematics, Dept. of Civil Engineering, Democritus Univ. of Thrace, Xanthi 67100, Greece
4. General Department, National & Kapodistrian University of Athens, Euripus Campus 34400, Greece