1. Business School, Georgian-American University, 8 Aleksidze Street, Tbilisi 0193, Georgia
2. Department of Stochastic Analysis and Mathematical Modeling, Institute of Cybernetics of Georgian Technical University, 5 Anjaparidze Street, Tbilisi 0186, Georgia
3. Department of Probability Theory and Mathematical Statistic, Razmadze Mathematical Institute of Tbilisi State University, 2 Aleksidze Street, Tbilisi 0193, Georgia