Robust Optimization

A Robust Location-Allocation Model for Optimizing a Multi-Echelon Blood Supply Chain Network Under Uncertainty

  • Masoud Asadpour Ahmadchali
  • Mahdi Ebrahimzadeh Afrouzi
    • Categories Robust Optimization, Supply Chain Management Tags , , , , ,

    Designing and planning blood supply chains is very complicated due to its uncertain nature, such as uncertain blood demand, high vulnerability to disruptions, irregular donation, and blood perishability. In this vein, this paper seeks to optimize a multi-echelon blood supply chain network under uncertainty by designing a robust location-allocation model. The magnitude of the earthquake … Read more

    Set-based Robust Optimization of Uncertain Multiobjective Problems via Epigraphical Reformulations

  • Gabriele Eichfelder
  • Ernest Quintana
    • Categories Multi-Criteria Optimization, Robust Optimization Tags , , ,

    In this paper, we study a method for finding robust solutions to multiobjective optimization problems under uncertainty. We follow the set-based minmax approach for handling the uncertainties which leads to a certain set optimization problem with the strict upper type set relation. We introduce, under some assumptions, a reformulation using instead the strict lower type … Read more

    On Generalization and Regularization via Wasserstein Distributionally Robust Optimization

  • Jonathan Yu-Meng Li
    • Categories Robust Optimization, Stochastic Programming Tags , , ,

    Wasserstein distributionally robust optimization (DRO) has found success in operations research and machine learning applications as a powerful means to obtain solutions with favourable out-of-sample performances. Two compelling explanations for the success are the generalization bounds derived from Wasserstein DRO and the equivalency between Wasserstein DRO and the regularization scheme commonly applied in machine learning. … Read more

    A Brief Introduction to Robust Bilevel Optimization

  • Yasmine Beck
  • Ivana Ljubić
  • Martin Schmidt
    • Categories Robust Optimization Tags , ,

    Bilevel optimization is a powerful tool for modeling hierarchical decision making processes. However, the resulting problems are challenging to solve – both in theory and practice. Fortunately, there have been significant algorithmic advances in the field so that we can solve much larger and also more complicated problems today compared to what was possible to … Read more

    Distributionally Robust Optimal Allocation with Costly Verification

  • Halil İbrahim Bayrak
  • Çağıl Koçyiğit
  • Daniel Kuhn
  • Mustafa C. Pinar
    • Categories Robust Optimization Tags , ,

    We consider the mechanism design problem of a principal allocating a single good to one of several agents without monetary transfers. Each agent desires the good and uses it to create value for the principal. We designate this value as the agent’s private type. Even though the principal does not know the agents’ types, she … Read more

    General Polyhedral Approximation of Two-Stage Robust Linear Programming

  • LukasGrunau
  • Tim Niemann
  • Sebastian Stiller
    • Categories Approximation Algorithms, Combinatorial Optimization, Robust Optimization Tags , , , ,

    \(\) We consider two-stage robust linear programs with uncertain righthand side. We develop a General Polyhedral Approximation (GPA), in which the uncertainty set $\mathcal{U}$ is substituted by a finite set of polytopes derived from the vertex set of an arbitrary polytope that dominates $\mathcal{U}$. The union of the polytopes need not contain $\mathcal{U}$. We analyse … Read more

    Exact Approaches for Convex Adjustable Robust Optimization

  • Henri Lefebvre
  • Enrico Malaguti
  • Michele Monaci
    • Categories Robust Optimization, Stochastic Programming Tags ,

    Adjustable Robust Optimization (ARO) is a paradigm for facing uncertainty in a decision problem, in case some recourse actions are allowed after the actual value of all input parameters is revealed. While several approaches have been introduced for the linear case, little is known regarding exact methods for the convex case. In this work, we … Read more

    Machine Learning for K-adaptability in Two-stage Robust Optimization

  • Esther Julien
  • Krzysztof Postek
  • Ş. İlker Birbil
    • Categories Robust Optimization Tags , , , , ,

    Two-stage robust optimization problems constitute one of the hardest optimization problem classes.One of the solution approaches to this class of problems is K-adaptability. This approach simultaneously seeks the best partitioning of the uncertainty set of scenarios into K subsets, and optimizesdecisions corresponding to each of these subsets. In general case, it is solved using the … Read more

    Wasserstein Regularization for 0-1 Loss

  • Rui Gao
    • Categories Data Science Theory, Robust Optimization, Stochastic Programming

    Wasserstein distributionally robust optimization (DRO) finds robust solutions by hedging against data perturbation specified by distributions in a Wasserstein ball. The robustness is linked to the regularization effect, which has been studied for continuous losses in various settings. However, existing results cannot be simply applied to the 0-1 loss, which is frequently seen in uncertainty … Read more

    Decision-making with Side Information: A Causal Transport Robust Approach

  • Jincheng Yang
  • Luhao Zhang
  • Ningyuan Chen
  • Rui Gao
  • Ming Hu
    • Categories Optimization in Data Science, Robust Optimization, Stochastic Programming Tags , , ,

    We consider stochastic optimization with side information where, prior to decision making, covariate data are available to inform better decisions. In particular, we propose to consider a distributionally robust formulation based on causal transport distance. Compared with divergence and Wasserstein metric, the causal transport distance is better at capturing the information structure revealed from the conditional distribution … Read more