Supermodularity, Curvature, and Convex Relaxations in a Class of Quadratic Binary Optimization Problems

  • Bismark Singh
    • Categories Combinatorial Optimization, Convex and Nonsmooth Optimization Tags , , ,

    We study the combinatorial structure of a quadratic set function $F(S)$ arising from a class of binary optimization models within the family of undesirable facility location problems. Despite strong empirical evidence of nested optimal solutions in previously studied real-world instances, we show that $F(S)$ is, in general, neither submodular nor supermodular. To quantify deviation from … Read more

    Stochastic Mixed-Integer Programming: A Survey

  • Ward Romeijnders
  • Yihang Zhang
  • Suvrajeet Sen
    • Categories Stochastic Programming Tags ,

    The goal of this survey is to provide a road-map for exploring the growing area of stochastic mixed-integer programming (SMIP) models and algorithms. We provide a comprehensive overview of existing decomposition algorithms for two-stage SMIPs, including Dantzig-Wolfe decomposition, dual decomposition, Lagrangian cuts, and decomposition approaches using parametric cutting planes and scaled cuts. Moreover, we explicitly … Read more

    Structure-Preserving Symmetry Presolving for Mixed-Binary Linear Problems

  • Annika Jaeger
  • Marc E. Pfetsch
    • Categories (Mixed) Integer Linear Programming, 0-1 Programming Tags , ,

    This paper investigates a presolving method for handling symmetries in mixed-binary programs, based on inequalities computed from so-called Schreier-Sims tables. We show that an iterative application of this method together with merging variables will produce an instance for which the symmetry group is trivial. We then prove that the problem structure can be preserved for … Read more

    An alternating optimization approach for robust optimal control in chromatography

  • Dominik H. Cebulla
  • Andrea Gilch
  • Jan Hendrik Rolfes
  • Christian Kirches
  • Frauke Liers
    • Categories Optimization of Systems modeled by PDEs, Robust Optimization Tags , ,

    Chromatographic separation plays a vital role in various areas, as this technique can deliver high-quality products both in lab- and industrial-scale processes. Economical and also ecological benefits can be expected when optimizing such processes with mathematical methods. However, even small perturbations in the operating conditions can result in significantly altered results, which may lead to … Read more

    The Decentralized Trust-Region Method with Second-Order Approximations

  • Hong Wang
    • Categories Parallel Algorithms Tags , ,

    This paper presents a novel decentralized trust-region framework that systematically incorporates second-order information to solve general nonlinear optimization problems in multi-agent networks. Our approach constructs local quadratic models that simultaneously capture objective curvature and enforce consensus through penalty terms, while supporting multiple Hessian approximation strategies including exact Hessians, limited-memory quasi-Newton methods, diagonal preconditioners, and matrix-free … Read more

    Min-Max Optimization Is Strictly Easier Than Variational Inequalities

  • Henry Shugart
  • Jason M. Altschuler
    • Categories Convex Optimization

    Classically, a mainstream approach for solving a convex-concave min-max problem is to instead solve the variational inequality problem arising from its first-order optimality conditions. Is it possible to solve min-max problems faster by bypassing this reduction? This paper initiates this investigation. We show that the answer is yes in the textbook setting of unconstrained quadratic … Read more

    Extended-Krylov-subspace methods for trust-region and norm-regularization subproblems

  • Hussam Al Daas
  • Nicholas I. M. Gould
    • Categories Constrained Nonlinear Optimization, Nonlinear Optimization, Unconstrained Optimization Tags , , ,

    We consider an effective new method for solving trust-region and norm-regularization problems that arise as subproblems in many optimization applications. We show that the solutions to such subproblems lie on a manifold of approximately very low rank as a function of their controlling parameters (trust-region radius or regularization weight). Based on this, we build a … Read more

    A One-Extra Player Reduction of GNEPs to NEPs

  • Henri Lefebvre
  • David Salas
  • Martin Schmidt
    • Categories Convex Optimization, Game Theory, Integer Programming Tags , , , ,

    It is common opinion that generalized Nash equilibrium problems are harder than Nash equilibrium problems. In this work, we show that by adding a new player, it is possible to reduce many generalized problems to standard equilibrium problems. The reduction holds for linear problems and smooth convex problems verifying a Slater-type condition. We also derive … Read more

    generalizing the successive shortest path algorithm to solve the multi-objective assignment problem

  • Antonio Sedeño-Noda
    • Categories Multi-Criteria Optimization, Network Optimization, Other Topics Tags , ,

    We introduce a novel characterization of the efficient solutions to the Multi-objective Assignment Problem (MAP), relying solely on Network Flow theory. This result establishes that the set of efficient assignments restricted to the first $k$ origin-destination pairs in the associated bipartite graph can be derived incrementally from the efficient solutions corresponding to the first $k-1$ … Read more

    Column Generation for Generalized Min-Cost Flows with Losses

  • Jonas Alker
  • Marc E. Pfetsch
    • Categories Combinatorial Optimization, Linear Programming, Network Optimization Tags ,

    The generalized flow problem deals with flows through a network with losses or gains along the arcs. Motivated by energy networks, this paper concentrates on the case with losses along cycles. Such networks can become extremely large, mostly because they are considered over large time horizons. We therefore develop a column generation approach for a … Read more