Cutting Box Strategy: an algorithmic framework for improving metaheuristics for continuous global optimization

  • Marcia Fampa
  • Wendel Melo
  • Fernanda M. P. Raupp
    • Categories Constrained Nonlinear Optimization, Stochastic Approaches Tags , , ,

    In this work, we present a new framework to increase effectiveness of metaheuristics in seeking good solutions for the general nonlinear optimization problem, called Cutting Box Strategy (CBS). CBS is based on progressive reduction of the search space through the use of intelligent multi-starts, where solutions already obtained cannot be revisited by the adopted metaheuristic. … Read more

    Multi-period fund performance evaluation: A dynamic network DEA approach with diversification and the directional distance function

  • Zhiping Chen
  • Qianhui Hu
  • Ruiyue Lin
    • Categories Finance and Economics

    When analyzing the relative performance of mutual funds, current data envelopment analysis (DEA) models with diversification only consider risks and returns over the entire investment process, which ignore the performance change in consecutive periods. This paper introduces a novel multi-period network DEA approach with diversification and the directional distance function. The new approach decomposes the … Read more

    Stochastic Approximations and Perturbations in Forward-Backward Splitting for Monotone Operators

  • Patrick L. Combettes
  • Jean-Christophe Pesquet
    • Categories Infinite Dimensional Optimization, Stochastic Programming Tags , , , , ,

    We investigate the asymptotic behavior of a stochastic version of the forward-backward splitting algorithm for finding a zero of the sum of a maximally monotone set-valued operator and a cocoercive operator in Hilbert spaces. Our general setting features stochastic approximations of the cocoercive operator and stochastic perturbations in the evaluation of the resolvents of the … Read more

    Uniform Convergence of Sample Average Approximation with Adaptive Importance Sampling

  • Mingbin Feng
  • Alvaro Maggiar
  • Jeremy Staum
  • Andreas Wächter
    • Categories Stochastic Programming Tags , , , ,

    We study sample average approximations under adaptive importance sampling. Based on a Banach-space-valued martingale strong law of large numbers, we establish uniform convergence of the sample average approximation to the function being approximated. In the optimization context, we obtain convergence of the optimal value and optimal solutions of the sample average approximation. CitationTechnical Report IEMS … Read more

    Discrete flow pooling problems in coal supply chains

  • Natashia Boland
  • Thomas Kalinowski
  • Fabian Rigterink
    • Categories (Mixed) Integer Nonlinear Programming, Constrained Nonlinear Optimization, Global Optimization Applications

    The pooling problem is a nonconvex nonlinear programming problem (NLP) with applications in the refining and petrochemical industries, but also the coal mining industry. The problem can be stated as follows: given a set of raw material suppliers (inputs) and qualities of the supplies, find a cost-minimising way of blending these raw materials in intermediate … Read more

    Error bounds for mixed integer nonlinear optimization problems

  • Oliver Stein
    • Categories (Mixed) Integer Nonlinear Programming Tags , , ,

    We introduce a-posteriori and a-priori error bounds for optimality and feasibility of a point generated as the rounding of an optimal point of the NLP relaxation of a mixed-integer nonlinear optimization problem. Our analysis mainly bases on the construction of a tractable approximation of the so-called grid relaxation retract. Under appropriate Lipschitz assumptions on the … Read more

    Pickup and delivery problem with time windows: a new compact two-index formulation

  • Maria Gabriela S. Furtado
  • Reinaldo Morabito
  • Pedro Munari
    • Categories Combinatorial Optimization, Integer Programming, Transportation

    We propose a formulation for the pickup and delivery problem with time windows, based on a novel modeling strategy that allows the assignment of vehicles to routes explicitly in two-index flow formulations. It leads to an effective compact formulation that can benefit OR practitioners interested in solving the problem by general-purpose optimization software. Computational experiments … Read more

    Evaluation complexity for nonlinear constrained optimization using unscaled KKT conditions and high-order models

  • Ernesto G. Birgin
  • José Mario Martínez
  • Sandra Augusta Santos
  • Philippe L. Toint
  • John L. Gardenghi
    • Categories Bound-constrained Optimization, Constrained Nonlinear Optimization Tags , , ,

    The evaluation complexity of general nonlinear, possibly nonconvex,constrained optimization is analyzed. It is shown that, under suitable smoothness conditions, an $\epsilon$-approximate first-order critical point of the problem can be computed in order $O(\epsilon^{1-2(p+1)/p})$ evaluations of the problem’s function and their first $p$ derivatives. This is achieved by using a two-phases algorithm inspired by Cartis, Gould, … Read more

    Global convergence of a derivative-free inexact restoration filter algorithm for nonlinear programming

  • Priscila Savulski Ferreira
  • Elizabeth Wegner Karas
  • Mael Sachine
  • Francisco N. C. Sobral
    • Categories Constrained Nonlinear Optimization Tags , , , , ,

    In this work we present an algorithm for solving constrained optimization problems that does not make explicit use of the objective function derivatives. The algorithm mixes an inexact restoration framework with filter techniques, where the forbidden regions can be given by the flat or slanting filter rule. Each iteration is decomposed in two independent phases: … Read more

    A special case of the generalized pooling problem arising in the mining industry

  • Natashia Boland
  • Thomas Kalinowski
  • Fabian Rigterink
  • Martin Savelsbergh
    • Categories Constrained Nonlinear Optimization, Global Optimization Applications

    Iron ore and coal are substantial contributors to Australia’s export economy. Both are blended products that are made-to-order according to customers’ desired product qualities. Mining companies have a great interest in meeting these target qualities since deviations generally result in contractually agreed penalties. This paper studies a variation of the generalized pooling problem (GPP) arising … Read more