1. Financial Mathematics and Actuarial Science (FMAS)- Research Group, Department of Mathematics, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
2. Department of Applied Mathematics, National University of Science and Technology Politehnica Bucharest, Bucharest, Romania
3. Fundamental Sciences Applied in Engineering -- Research Center (SFAI), National University of Science and Technology Politehnica Bucharest, Bucharest, Romania
4. Academy of Romanian Scientists, Bucharest, Romania