An adaptive relaxation-refinement scheme for multi-objective mixed-integer nonconvex optimization

  • Gabriele Eichfelder
  • Moritz Link
  • Stefan Volkwein
  • Leo Warnow
    • Categories (Mixed) Integer Nonlinear Programming, Multi-Criteria Optimization Tags , , , ,

    In this work, we present an algorithm for computing an enclosure for multi-objective mixed-integer nonconvex optimization problems. In contrast to existing solvers for this type of problem, this algorithm is not based on a branch-and-bound scheme but rather relies on a relax-and-refine approach. While this is an established technique in single-objective optimization, several adaptions to … Read more

    Forecasting Urban Traffic States with Sparse Data Using Hankel Temporal Matrix Factorization

  • Chun Cheng
    • Categories Data Science Algorithms, Data Science Applications, Transportation Tags , , , ,

    Forecasting urban traffic states is crucial to transportation network monitoring and management, playing an important role in the decision-making process. Despite the substantial progress that has been made in developing accurate, efficient, and reliable algorithms for traffic forecasting, most existing approaches fail to handle sparsity, high-dimensionality, and nonstationarity in traffic time series and seldom consider … Read more

    Properties of Two-Stage Stochastic Multi-Objective Linear Programs

  • Akshita Gupta
  • Susan R. Hunter
    • Categories Multi-Criteria Optimization, Other Topics, Stochastic Programming Tags , ,

    We consider a two-stage stochastic multi-objective linear program (TSSMOLP) which is a natural generalization of the well-studied two-stage stochastic linear program (TSSLP) allowing modelers to specify multiple objectives in each stage. The second-stage recourse decision is governed by an uncertain multi-objective linear program (MOLP) whose solution maps to an uncertain second-stage nondominated set. The TSSMOLP … Read more

    A new framework to generate Lagrangian cuts in multistage stochastic mixed-integer programming

  • Christian Füllner
  • Xu Andy Sun
  • Steffen Rebennack
    • Categories (Mixed) Integer Linear Programming, Stochastic Programming Tags , , , , ,

    Based on recent advances in Benders decomposition and two-stage stochastic integer programming we present a new generalized framework to generate Lagrangian cuts in multistage stochastic mixed-integer linear programming (MS-MILP). This framework can be incorporated into decomposition methods for MS-MILPs, such as the stochastic dual dynamic integer programming (SDDiP) algorithm. We show how different normalization techniques … Read more

    Immunity to Increasing Condition Numbers of Linear Superiorization versus Linear Programming

  • Jan Schröder
  • Yair Censor
  • Philipp Süss
  • Karl-Heinz Küfer
    • Categories Basic Sciences Applications, Constrained Nonlinear Optimization, Linear Programming Tags , , , , , , ,

    Given a family of linear constraints and a linear objective function one can consider whether to apply a Linear Programming (LP) algorithm or use a Linear Superiorization (LinSup) algorithm on this data. In the LP methodology one aims at finding a point that fulfills the constraints and has the minimal value of the objective function … Read more

    On Lipschitz regularization and Lagrangian cuts in multistage stochastic mixed-integer linear programming

  • Christian Füllner
  • Xu Andy Sun
  • Steffen Rebennack
    • Categories (Mixed) Integer Linear Programming, Stochastic Programming Tags , , , , ,

    We provide new theoretical insight on the generation of linear and non-convex cuts for value functions of multistage stochastic mixed-integer programs based on Lagrangian duality. First, we analyze in detail the impact that the introduction of copy constraints, and especially, the choice of the accompanying constraint set for the copy variable have on the properties … Read more

    On the Trade-Off Between Distributional Belief and Ambiguity: Conservatism, Finite-Sample Guarantees, and Asymptotic Properties

  • Man Yiu Tsang
  • Karmel S. Shehadeh
    • Categories Robust Optimization, Stochastic Programming Tags , , , ,

    We propose and analyze a new data-driven trade-off (TRO) approach for modeling uncertainty that serves as a middle ground between the optimistic approach, which adopts a distributional belief, and the pessimistic distributionally robust optimization approach, which hedges against distributional ambiguity. We equip the TRO model with a TRO ambiguity set characterized by a size parameter … Read more

    Application of the Lovász-Schrijver Operator to Compact Stable Set Integer Programs

  • Federico Battista
  • Fabrizio Rossi
  • Stefano Smriglio
    • Categories 0-1 Programming, Combinatorial Optimization, Semi-definite Programming Tags , ,

    The Lov\’asz theta function $\theta(G)$ provides a very good upper bound on the stability number of a graph $G$. It can be computed in polynomial time by solving a semidefinite program (SDP), which also turns out to be fairly tractable in practice. Consequently, $\theta(G)$ achieves a hard-to-beat trade-off between computational effort and strength of the … Read more

    Modified Line Search Sequential Quadratic Methods for Equality-Constrained Optimization with Unified Global and Local Convergence Guarantees

  • Albert S. Berahas
  • Raghu Bollapragada
  • Jiahao Shi
    • Categories Constrained Nonlinear Optimization, Nonlinear Optimization, Other Topics Tags , ,

    In this paper, we propose a method that has foundations in the line search sequential quadratic programming paradigm for solving general nonlinear equality constrained optimization problems. The method employs a carefully designed modified line search strategy that utilizes second-order information of both the objective and constraint functions, as required, to mitigate the Maratos effect. Contrary … Read more