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- P. A. Pereira, F. A. C. C. Fontes, D. B. M. M. Fontes, Roberto Frias
- 2007

We report on the development of a Decision Support System (DSS) to plan the best assignment for the weekly promotion space of a TV station. Each product to promote has a given target audience that is best reached at specific time periods during the week. The DSS aims to maximize the total viewing for each product within its target audience while fulfilling… (More)

—This note proposes a model predictive control (MPC) algorithm for the solution of a robust control problem for continuous-time systems. Discontinuous feedback strategies are allowed in the solution of the min–max problems to be solved. The use of such strategies allows MPC to address a large class of nonlinear systems, including among others nonholo-nomic… (More)

A Biased Random Key Genetic Algorithm (BRKGA) is proposed to find solutions for the unit commitment problem. In this problem, one wishes to schedule energy production on a given set of thermal generation units in order to meet energy demands at minimum cost, while satisfying a set of technological and spinning reserve constraints. In the BRKGA, solutions… (More)

In this work we address the Hop-Constrained Minimum cost Flow Spanning Tree (HMFST) problem with nonlinear costs. The HMFST problem is an extension of the Hop-Constrained Minimum Spanning Tree problem since it considers flow requirements other than unit flows. We propose a hybrid heuristic, based on Ant Colony Optimization (ACO) and on Local Search (LS), to… (More)

Acknowledgements I would like to express my deep and sincere gratitude to my supervisor Professor Fernando A. C. C. Fontes for his advice, his supervision and his crucial contributions which made him a backbone of this research and thus of this thesis. Besides I am deeply grateful to Professor Maria do Rosário de Pinho, for her detailed and constructive… (More)

In this work we address the Singe-Source Uncapacitated Minimum Cost Network Flow Problem with concave cost functions. Given that this problem is of a combinatorial nature and also that the total costs are nonlinear, we propose a hybrid heuristic to solve it. In this type of algorithms one usually tries to manage two conflicting aspects of searching… (More)

There has been a longstanding interest in deriving conditions under which dynamic optimization problems are normal, that is, the necessary conditions of optimality (NCO) can be written with a nonzero multiplier associated with the objective function. This paper builds upon previous results on nondegenerate NCO for trajectory constrained optimal control… (More)

— There are certain optimal control problems with state constraints for which the standard versions of the necessary conditions of optimality are unable to provide information to select minimizers. In the recent years, there has been some literature on stronger forms of the maximum principle, the so-called nondegenerate necessary conditions, that are… (More)