Publications

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2016
Salmerón, J. M. G., P. Amaral, L. G. Casado, E. M. T. Hendrix, and J. Żilinskas. "On Regular Simplex Refinement in Copositivity Detection." XIII global optimization workshop GOW2016 4-8 September 2016. 2016. 163-166. Abstract
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2014
Gomes, Isabel, Jorge Santos, Luís Cavique, Nelson C. Martins, Manuel Vieira, Paula Amaral, Raquel Barreira, and Vitor H. Fernandes AMT (airline maintenance technicians) timetabling optimization- ESGI101 - Relatório Final- TAP-AMT. ESGI 101, FCT, UNL, 2014, 2014. Abstract
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2009
Amaral, P., L. M. Fernandes, J. Júdice, and H. D. Sherali. "On optimal zero-preserving corrections for inconsistent linear systems." Journal of Global Optimization. 45 (2009): 645-666. Abstract

This paper addresses the problem of finding an optimal correction of an inconsistent linear system, where only the nonzero coefficients of the constraint matrix are allowed to be perturbed for reconstructing a consistent system. Using the Frobenius norm as a measure of the distance to feasibility, a nonconvex minimization problem is formulated, whose objective function is a sum of fractional functions. A branch-and-bound algorithm for solving this nonconvex program is proposed, based on suitably overestimating the denominator function for computing lower bounds. Computational experience is presented to demonstrate the efficacy of this approach.

2008
Amaral, Paula, Joaquim Júdice, and Hanif D. Sherali. "A reformulation–linearization–convexification algorithm for optimal correction of an inconsistent system of linear constraints." Computers & Operations Research. 35 (2008): 1494-1509. Abstract
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