1. National Laboratory for Scientific Computing, Petrópolis, Rio de Janeiro, Brazil
2. Computation Institute, Argonne National Laboratory/University of Chicago, Chicago, IL, USA
3. Computer and Systems Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
4. National Center for Supercomputing Applications, University of Illinois, Urbana, IL, USA
5. Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil