1. Department of Mathematics, Federal University of Technology – Paraná, Londrina, PR, Brazil
2. Department Exact Sciences, University of São Paulo, Piracicaba, SP, Brazil
3. Department of Statistics, Federal University of Pernambuco, Recife, PE, Brazil
4. Institute of Mathematical and Computer Sciences, University of São Paulo, São Carlos, SP, Brazil
5. Graduate Program in Environmental Engineering, Federal University of Technology – Paraná, Londrina, PR, Brazil