conic quadratic optimization

Conic Mixed-Binary Sets: Convex Hull Characterizations and Applications

  • Fatma Kılınç-Karzan
  • Simge Küçükyavuz
  • Dabeen Lee
    • Categories (Mixed) Integer Nonlinear Programming Tags , , , , , , ,

    We consider a general conic mixed-binary set where each homogeneous conic constraint involves an affine function of independent continuous variables and an epigraph variable associated with a nonnegative function, $f_j$, of common binary variables. Sets of this form naturally arise as substructures in a number of applications including mean-risk optimization, chance-constrained problems, portfolio optimization, lot-sizing … Read more

    Outlier detection in time series via mixed-integer conic quadratic optimization

  • Andrés Gómez
    • Categories (Mixed) Integer Nonlinear Programming, Statistics Tags , , , , ,

    We consider the problem of estimating the true values of a Wiener process given noisy observations corrupted by outliers. The problem considered is closely related to the Trimmed Least Squares estimation problem, a robust estimation procedure well-studied from a statistical standpoint but poorly understood from an optimization perspective. In this paper we show how to … Read more

    Sparse and Smooth Signal Estimation: Convexification of L0 Formulations

  • Alper Atamturk
  • Andrés Gómez
  • Shaoning Han
    • Categories (Mixed) Integer Nonlinear Programming Tags , , , ,

    Signal estimation problems with smoothness and sparsity priors can be naturally modeled as quadratic optimization with L0-“norm” constraints. Since such problems are non-convex and hard-to-solve, the standard approach is, instead, to tackle their convex surrogates based on L1-norm relaxations. In this paper, we propose new iterative conic quadratic relaxations that exploit not only the L0-“norm” … Read more

    Strong formulations for conic quadratic optimization with indicator variables

  • Andrés Gómez
    • Categories (Mixed) Integer Nonlinear Programming Tags , , ,

    We study the convex hull of the mixed-integer set given by a conic quadratic inequality and indicator variables. Conic quadratic terms are often used to encode uncertainties, while the indicator variables are used to model fixed costs or enforce sparsity in the solutions. We provide the convex hull description of the set under consideration when … Read more

    Maximizing a class of utility functions over the vertices of a polytope

  • Alper Atamturk
  • Andrés Gómez
    • Categories (Mixed) Integer Nonlinear Programming, Robust Optimization, Stochastic Programming Tags , , , , , , , ,

    Given a polytope X, a monotone concave univariate function g, and two vectors c and d, we study the discrete optimization problem of finding a vertex of X that maximizes the utility function c’x + g(d’x). This problem has numerous applications in combinatorial optimization with a probabilistic objective, including estimation of project duration with stochastic … Read more