Applications – OR and Management Sciences

Two-stage and one-group two-dimensional guillotine cutting problems with defects: a CP-based algorithm and ILP formulations

  • Mateus Martin
  • Reinaldo Morabito
  • Pedro Munari
    • Categories Applications - OR and Management Sciences Tags , , , , , ,

    We address two variants of the two-dimensional guillotine cutting problem that appear in different manufacturing settings that cut defective objects. Real-world applications include the production of flat glass in the glass industry and the cutting of wooden boards with knotholes in the furniture industry. These variants assume that there are several defects in the object, … Read more

    Three-dimensional guillotine cutting problems with constrained patterns: MILP formulations and a bottom-up algorithm

  • Mateus Martin
  • Reinaldo Morabito
  • Pedro Munari
  • José Fernando Oliveira
  • Elsa Silva
    • Categories Applications - OR and Management Sciences

    In this paper, we address the Constrained Three-dimensional Guillotine Cutting Problem (C3GCP), which consists of cutting a larger cuboid block (object) to produce a limited number of smaller cuboid pieces (items) using orthogonal guillotine cuts only. This way, all cuts must be parallel to the object’s walls and generate two cuboid sub-blocks, and there is … Read more

    Vessel Deployment with Limited Information: Distributionally Robust Chance Constrained Models

  • Yue Zhao
  • Zhi Chen
  • Andrew Lim
  • Zhenzhen Zhang
    • Categories Robust Optimization, Transportation Tags , , , , ,

    This paper studies the fundamental vessel deployment problem in the liner shipping industry, which decides the numbers of mixed-type ships and their sailing frequencies on fixed routes to provide sufficient vessel capacity for fulfilling stochastic shipping demands with high probability. In reality, it is usually difficult (if not impossible) to acquire a precise joint distribution … Read more

    Scheduling the Brazilian OR Conference

  • Teobaldo Bulhões
  • Puca Huachi V. Penna
  • Anand Subramanian
  • Rubens Correia
    • Categories Meta Heuristics, Scheduling Tags , ,

    In this paper, we show how to efficiently schedule the Brazilian OR conference using a matheuristic approach. The event has traditionally around 300 presentations across a period of 3 to 4 days, and building a schedule for the technical sessions is an arduous task. The proposed algorithm integrates the concepts of iterated local search and … Read more

    Copositive Duality for Discrete Energy Markets

  • Cheng Guo
  • Merve Bodur
  • Joshua Taylor
    • Categories Applications - OR and Management Sciences Tags , , , ,

    Optimization problems with discrete decisions are nonconvex and thus lack strong duality, which limits the usefulness of tools such as shadow prices. It was shown in Burer (2009) that mixed-binary quadratic programs can be written as completely positive programs, which are convex. We apply this perspective by writing unit commitment in power systems as a … Read more

    Fairness over Time in Dynamic Resource Allocation with an Application in Healthcare

  • Andrea Lodi
  • Philippe Olivier
  • Gilles Pesant
  • Sriram Sankaranarayanan
    • Categories Branch and Cut Algorithms, Facility Planning and Design, Scheduling

    Decision making problems are typically concerned with maximizing efficiency. In contrast, we address problems where there are multiple stakeholders and a centralized decision maker who is obliged to decide in a fair manner. Different decisions give different utility to each stakeholder. In cases where these decisions are made repeatedly, we provide efficient mathematical programming formulations … Read more

    Multi-period Workload Balancing in Last-Mile Urban Delivery

  • Martin Savelsbergh
  • Yang Wang
  • Shengnan Wu
  • Lei Zhao
    • Categories Applications - OR and Management Sciences, Transportation Tags , , ,

    In the daily dispatching of urban deliveries, a delivery manager has to consider workload balance among the couriers to maintain workforce morale. We consider two types of workload: incentive workload, which relates to the delivery quantity and affects a courier’s income, and effort workload, which relates to the delivery time and affects a courier’s health. … Read more

    A Robust Approach for Modeling Limited Observability in Bilevel Optimization

  • Yasmine Beck
  • Martin Schmidt
    • Categories Finance and Economics, Robust Optimization Tags , , , ,

    In bilevel optimization, hierarchical optimization problems are considered in which two players – the leader and the follower – act and react in a non-cooperative and sequential manner. In many real-world applications, the leader may face a follower whose reaction deviates from the one expected by the leader due to some kind of bounded rationality. … Read more

    Solving Multiplicative Programs by Binary-encoding the Multiplication Operation

  • Hadi Charkhgard
  • Fabian Rigterink
  • Payman Ghasemi Saghand
  • Vahid Mahmoodian
    • Categories Applications - OR and Management Sciences, Game Theory Tags ,

    Multiplicative programs in the form of maximization and/or minimization have numerous applications in conservation planning, game theory, and multi-objective optimization settings. In practice, multiplicative programs are challenging to solve because of their multiplicative objective function (a product of continuous or integer variables). These challenges are twofold: 1. As the number of factors in the objective … Read more

    Model-Free Assortment Pricing with Transaction Data

  • Ningyuan Chen
  • Andre Augusto Cire
  • Ming Hu
  • Saman Lagzi
    • Categories Applications - OR and Management Sciences, Approximation Algorithms, Robust Optimization

    We study a problem in which a firm sets prices for products based on the transaction data, i.e., which product past customers chose from an assortment and what were the historical prices that they observed. Our approach does not impose a model on the distribution of the customers’ valuations and only assumes, instead, that purchase … Read more