Constrained Nonlinear Optimization

Disjunctive Cuts for Non-Convex Mixed Integer Quadratically Constrained Programs

  • Pierre Bonami
  • Jon Lee
  • Anureet Saxena
    • Categories (Mixed) Integer Nonlinear Programming, Constrained Nonlinear Optimization, Global Optimization Tags , , , ,

    This paper addresses the problem of generating strong convex relaxations of Mixed Integer Quadratically Constrained Programming (MIQCP) problems. MIQCP problems are very difficult because they combine two kinds of non-convexities: integer variables and non-convex quadratic constraints. To produce strong relaxations of MIQCP problems, we use techniques from disjunctive programming and the lift-and-project methodology. In particular, … Read more

    Rigorous enclosures of ellipsoids and directed Cholesky factorizations

  • Ferenc Domes
  • Arnold Neumaier
    • Categories Constrained Nonlinear Optimization Tags , , , , , , , , ,

    This paper discusses the rigorous enclosure of an ellipsoid by a rectangular box, its interval hull, providing a convenient preprocessing step for constrained optimization problems. A quadratic inequality constraint with a positive definite Hessian defines an ellipsoid. The Cholesky factorization can be used to transform a strictly convex quadratic constraint into a norm inequality, for … Read more

    A scaling algorithm for polynomial constraint satisfaction problems

  • Ferenc Domes
  • Arnold Neumaier
    • Categories Constrained Nonlinear Optimization Tags , ,

    Good scaling is an essential requirement for the good behavior of many numerical algorithms. In particular, for problems involving multivariate polynomials, a change of scale in one or more variable may have drastic effects on the robustness of subsequent calculations. This paper surveys scaling algorithms for systems of polynomials from the literature, and discusses some … Read more

    Formulation of Oligopolistic Competition in AC Power Networks: An NLP Approach

  • Miguel F. Anjos
  • Guillermo Bautista
  • Anthony Vannelli
    • Categories Applications - Science and Engineering, Constrained Nonlinear Optimization, Game Theory Tags , , , , ,

    In this paper, oligopolistic competition in a centralized power market is characterized by a multi-leader single-follower game, and formulated as a nonlinear programming (NLP) problem. An AC network is used to represent the transmission system and is modeled using rectangular coordinates. The follower is composed of a set of competitive suppliers, demands, and the system … Read more

    Numerical Study of Affine Supply Function Equilibrium in AC Network-Constrained Markets

  • Miguel F. Anjos
  • Guillermo Bautista
  • Anthony Vannelli
    • Categories Applications - Science and Engineering, Constrained Nonlinear Optimization, Game Theory Tags , , , , , , ,

    An affine supply function equilibrium (SFE) approach is used to discuss voltage constraints and reactive power issues in the modeling of strategic behavior. Generation companies (GenCos) can choose their bid parameters with no restrictions for both energy and spinning reserves. The strategic behavior of generators is formulated as a multi-leader single-follower game. Each GenCo is … Read more

    LANCELOt_simple, a simple interface to LANCELOT B

  • Nicholas I. M. Gould
  • Dominique Orban
  • Philippe L. Toint
    • Categories Constrained Nonlinear Optimization, Nonlinear Optimization, Optimization Software and Modeling Systems Tags , ,

    We describe LANCELOT_simple, an interface to the LANCELOT B nonlinear optimization package within the GALAHAD} library (Gould, Orban, Toint, 2003) which ignores problem structure. The result is an easy-to-use Fortran 90 subroutine, with a small number of intuitively interpretable arguments. However, since structure is ignored, the means of presenting problems to the solver limited and … Read more

    Two theoretical results for sequential semidefinite programming

  • Rodrigo Garcés
  • Walter Gómez
  • Florian Jarre
    • Categories Constrained Nonlinear Optimization, Linear, Cone and Semidefinite Programming, Optimization Software and Modeling Systems Tags , , , , , ,

    We examine the local convergence of a sequential semidefinite programming approach for solving nonlinear programs with nonlinear semidefiniteness constraints. Known convergence results are extended to slightly weaker second order sufficient conditions and the resulting subproblems are shown to have local convexity properties that imply a weak form of self-concordance of the barrier subproblems. Citation Preprint, … Read more

    Combining segment generation with direct step-and-shoot optimization in intensity-modulated radiation therapy

  • Fredrik Carlsson
    • Categories Biomedical Applications, Constrained Nonlinear Optimization Tags , , ,

    A method for generating a sequence of intensity-modulated radiation therapy step-and-shoot plans with increasing number of segments is presented. The objectives are to generate high-quality plans with few, large and regular segments, and to make the planning process more intuitive. The proposed method combines segment generation with direct step-and-shoot optimization, where leaf positions and segment … Read more

    On the solution of fuzzy bilevel programming problems

  • Stephan Dempe
  • Tatiana Starostina
    • Categories Constrained Nonlinear Optimization, Game Theory

    In this paper we formulate the fuzzy bilevel programming problem and describe one possible approach for formulating a crisp optimization problem being attached to it. Due to the nature of fuzzy bilevel programming this is a crisp bilevel programming problem. We compare our approach with one using multicriterial optimization and show, that both approaches are … Read more

    A Filter Active-Set Trust-Region Method

  • Michael P. Friedlander
  • Nicholas I. M. Gould
  • Sven Leyffer
  • Todd S. Munson
    • Categories Constrained Nonlinear Optimization, Nonlinear Optimization Tags , ,

    We develop a new active-set method for nonlinear programming problems that solves a regularized linear program to predict the active set and then fixes the active constraints to solve an equality-constrained quadratic program for fast convergence. Global convergence is promoted through the use of a filter. We show that the regularization parameter fulfills the same … Read more