Xu Andy Sun

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

    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

    BattOpt: Optimal Facility Planning for Electric Vehicle Battery Recycling

  • Matthew Brun
  • Xu Andy Sun
    • Categories Energy, Global Optimization Applications, Stochastic Programming Tags , , ,

    The electric vehicle (EV) battery supply chain will face challenges in sourcing scarce, expensive minerals required for manufacturing and in disposing of hazardous retired batteries. Integrating recycling technology into the supply chain has the potential to alleviate these issues; however, players in the battery market must design investment plans for recycling facilities. In this paper, … Read more

    Optimal Planning for the Electrification of Bus Fleets in Public Transit Systems

  • Filipe Cabral
  • Xu Andy Sun
    • Categories Applications - OR and Management Sciences, Integer Programming, Transportation Tags , , ,

    Electric vehicles (EV) pave a promising way towards low-carbon transportation, but the transition to all EV fleets creates new challenges for the public transportation sector. Despite increasing adoption of electric buses, the main challenges presented by the battery electric bus technology include the lack of charging facilities, the reduced operating capacity per battery charge compared … Read more

    Robust Optimization with Continuous Decision-Dependent Uncertainty with Applications in Demand Response Portfolio Management

  • Hongfan(Kevin) Chen
  • Xu Andy Sun
  • Haoxiang Yang
    • Categories Applications - OR and Management Sciences, Robust Optimization Tags , ,

    We consider a robust optimization problem with continuous decision-dependent uncertainty (RO-CDDU), which has two new features: an uncertainty set linearly dependent on continuous decision variables and a convex piecewise-linear objective function. We prove that RO-CDDU is strongly NP-hard in general and reformulate it into an equivalent mixed-integer nonlinear program (MINLP) with a decomposable structure to … Read more