1. Department of Basic Sciences Universidad del Sinú Montería Colombia
2. School of Industrial Engineering Pontificia Universidad Católica de Valparaíso Valparaíso Chile
3. Department of Statistics Universidade de Brasília Brasília Brazil
4. Faculty of Administration, Accounting and Economics Universidade Federal de Goiás Goiânia Brazil
5. Institute of Applied Mathematics and Information Technology CNR Milan Italy