robust optimization

Robust Network Design for Potential-Based Flows with Controllable Elements

  • Kristina Rolsing
  • Johannes Thürauf
    • Categories (Mixed) Integer Nonlinear Programming, Bilevel Optimization, Robust Optimization Tags , , , ,

    We study adjustable robust network design for potential-based flows with controllable elements under load uncertainty. The resulting problem combines discrete here-and-now expansion decisions with wait-and-see operational decisions governed by nonconvex flow constraints. Moreover, controllable elements introduce adjustable integer decisions, which are algorithmically challenging. We equivalently characterize robust feasibility and robust optimality of a fixed network … Read more

    PyROS: The Pyomo Robust Optimization Solver

  • Jason A. F. Sherman
  • Natalie M. Isenberg
  • John D. Siirola
  • Chrysanthos E. Gounaris
    • Categories Nonlinear Optimization, Optimization Software and Modeling Systems, Robust Optimization Tags , , , ,

    We present PyROS, a Python-based meta-solver that automates a generalized cutting-set algorithm for the solution of nonconvex two-stage robust optimization (RO) problems with uncertain equality constraints. Freely available through the open-source optimization software package Pyomo, PyROS is designed to operate on a user-provided deterministic model and uncertainty set, such that a solution to the RO … Read more

    Distributionally Robust Optimization with General Uncertainty Structure

  • Judith Brugman
  • Dimitris Bertsimas
  • Johan Van Leeuwaarden
  • Dick den Hertog
    • Categories Nonlinear Optimization, Robust Optimization, Stochastic Programming Tags , , , , , ,

    We develop an exact solution framework for a broad class of Distributionally Robust Optimization (DRO) problems with general uncertainty structure. Within the class of moment- and confidence-set-based ambiguity sets, existing exact methods are largely limited to max-of-affine functions under ambiguity sets with strictly nested confidence sets. To enlarge this scope while preserving tractability, we introduce … Read more

    Robust Bilevel Optimization with a Wait-and-See Follower: A Column-and-Constraint Generation Approach

  • Henri Lefebvre
  • Johannes Thürauf
    • Categories Bilevel Optimization, Robust Optimization Tags , , , ,

    We study optimistic robust bilevel problems with uncertainty in the follower’s problem, where the follower adopts a so-called wait-and-see approach. In this setting, the leader decides without knowledge of the specific realization of the uncertainty. Then, the uncertainty realizes in a worst-case manner, and afterward the follower makes her own decisions. For this challenging problem … Read more

    Globalized Adversarial Regret Optimization: Robust Decisions with Uncalibrated Predictions

  • Jannis Kurtz
  • Bart Paul Gerard van Parys
    • Categories Robust Optimization, Stochastic Programming Tags , ,

    Optimization problems routinely depend on uncertain parameters that must be predicted before a decision is made. Classical robust and regret formulations are designed to handle erroneous predictions and can provide statistical error bounds in simple settings. However, when predictions lack rigorous error bounds (as is typical of modern machine learning methods) classical robust models often … Read more

    Modeling Adversarial Wildfires for Power Grid Disruption

  • Matthew Brun
  • Xu Andy Sun
  • Jean-Paul Watson
    • Categories (Mixed) Integer Nonlinear Programming, Energy, Second-Order Cone Programming Tags , , , ,

    Electric power infrastructure faces increasing risk of damage and disruption due to wildfire. Operators of power grids in wildfire-prone regions must consider the potential impacts of unpredictable fires. However, traditional wildfire models do not effectively describe worst-case, or even high-impact, fire behavior. To address this issue, we propose a mixed-integer conic program to characterize an … Read more

    Branch-and-Cut for Mixed-Integer Linear Decision-Dependent Robust Optimization

  • Henri Lefebvre
  • Martin Schmidt
  • Simon Stevens
  • Johannes Thürauf
    • Categories Bilevel Optimization, Branch and Cut Algorithms, Robust Optimization Tags , , , , ,

    Decision-dependent robust optimization (DDRO) problems are usually tackled by reformulating them using a strong-duality theorem for the uncertainty set model. If the uncertainty set is, however, described by a mixed-integer linear model, dualization techniques cannot be applied and the literature on solution methods is very scarce. In this paper, we exploit the equivalence of DDRO … Read more

    Linear Model Extraction via Factual and Counterfactual Queries

  • Daan Otto
  • Jannis Kurtz
  • Dick den Hertog
  • Ş. İlker Birbil
    • Categories Data Science Algorithms, Data Science Theory, Optimization in Data Science Tags , ,

    In model extraction attacks, the goal is to reveal the parameters of a black-box machine learning model by querying the model for a selected set of data points. Due to an increasing demand for explanations, this may involve counterfactual queries besides the typically considered factual queries. In this work, we consider linear models and three … Read more

    Exact and Heuristic Methods for Gamma-Robust Min-Max Problems

  • Yasmine Beck
    • Categories Bilevel Optimization, Combinatorial Optimization, Robust Optimization Tags , , , ,

    Bilevel optimization is a powerful tool for modeling hierarchical decision-making processes, which arise in various real-world applications. Due to their nested structure, however, bilevel problems are intrinsically hard to solve—even if all variables are continuous and all parameters of the problem are exactly known. Further challenges arise if mixed-integer aspects and problems under uncertainty are … Read more