1. Department of Chemical Engineering, Federal University of Rio Grande do Sul, R. Eng. Luiz Englert, s/n, Campus Central, Porto Alegre, Rio Grande do Sul, Brazil
2. Department of Computer Science, University of Kaiserslautern, 67663 Kaiserslautern, Germany
3. Department of Computer Science, University of Southern California, 1002 Childs Way, Los Angeles, California, United States