Transportation

Solving Binary-Constrained Mixed Complementarity Problems Using Continuous Reformulations

  • Steven A. Gabriel
  • Martin Schmidt
  • Marina Leal
    • Categories (Mixed) Integer Nonlinear Programming, Complementarity and Variational Inequalities, Transportation Tags , , ,

    Mixed complementarity problems are of great importance in practice since they appear in various fields of applications like energy markets, optimal stopping, or traffic equilibrium problems. However, they are also very challenging due to their inherent, nonconvex structure. In addition, recent applications require the incorporation of integrality constraints. Since complementarity problems often model some kind … Read more

    Evaluating on-demand warehousing via dynamic facility location models

  • Kaan Unnu
  • Jennifer Pazour
    • Categories (Mixed) Integer Linear Programming, Supply Chain Management, Transportation Tags , , , , , ,

    On-demand warehousing platforms match companies with underutilized warehouse and distribution capabilities with customers who need extra space or distribution services. These new business models have unique advantages, in terms of reduced capacity and commitment granularity, but also have different cost structures compared to traditional ways of obtaining distribution capabilities. This research is the first quantitative … Read more

    Stochastic Last-mile Delivery with Crowd-shipping and Mobile Depots

  • Merve Bodur
  • Kianoush Mousavi
  • Matthew J. Roorda
    • Categories Stochastic Programming, Transportation Tags , , , , , ,

    This paper proposes a two-tier last-mile delivery model that optimally selects mobile depot locations in advance of full information about the availability of crowd-shippers, and then transfers packages to crowd-shippers for the final shipment to the customers. Uncertainty in crowd-shipper availability is incorporated by modeling the problem as a two-stage stochastic integer program. Enhanced decomposition … Read more

    Estimation of Marginal Cost to Serve Individual Customers

  • Jeffrey E. Arbogast
  • Chrysanthos E. Gounaris
  • Gildas Bonnier
  • Akang Wang
  • Zachary Wilson
    • Categories Supply Chain Management, Transportation Tags , , , ,

    This paper proposes a scenario sampling-based framework to estimate the expected incremental routing cost required so as to incorporate a target customer into an inherently stochastic supply chain network. Inspired from a real-life setting arising in the distribution of industrial gases, we demonstrate our framework and elucidate the quality of the marginal cost estimates it … Read more

    Substitution-based Equipment Balancing in Service Networks with Multiple Equipment Types

  • Natashia Boland
  • Alan L. Erera
  • Martin Savelsbergh
  • Yassine Ridouane
  • Yu Yang
    • Categories Applications - OR and Management Sciences, Transportation

    We investigate substitution-based equipment balancing for a package express carrier operating multiple equipment types in its service network. The weekly schedule of movements used to transport packages through the service network leads to changes in equipment inventory at the facilities in the network. We seek to reduce this change, i.e., the equipment imbalance associated with … Read more

    Dynamic programming for the time-dependent traveling salesman problem with time windows

  • Gonzalo Lera-Romero
  • Juan José Miranda-Bront
  • Francisco J. Soulignac
    • Categories Dynamic Programming, Transportation Tags , , , , ,

    The recent growth of direct-to-consumer deliveries has stressed the importance of last-mile logistics, becoming one of the critical factors in city planning. One of the key factors lies in the last-mile deliveries, reaching in some cases nearly 50% of the overall parcel delivery cost. Different variants of the the well-known Traveling Salesman Problem (TSP) arise … Read more

    Compact Formulations for Split Delivery Routing Problems

  • Pedro Munari
  • Martin Savelsbergh
    • Categories Branch and Cut Algorithms, Production and Logistics, Transportation Tags , , ,

    Split delivery routing problems are concerned with serving the demand of a set of customers with a fleet of capacitated vehicles at minimum cost, where a customer can be served by more than one vehicle if beneficial. They generalize traditional variants of routing problems and have applications in commercial as well as humanitarian logistics. Previously, … Read more

    Exact Methods for the Traveling Salesman Problem with Drone

  • Roberto Roberti
  • Mario Ruthmair
    • Categories (Mixed) Integer Linear Programming, Dynamic Programming, Transportation Tags , , , ,

    Efficiently handling last-mile deliveries becomes more and more important nowadays. Using drones to support classical vehicles allows improving delivery schedules as long as efficient solution methods to plan last-mile deliveries with drones are available. We study exact solution approaches for some variants of the traveling salesman problem with drone (TSP-D) in which a truck and … Read more

    Gamma-Robust Linear Complementarity Problems with Ellipsoidal Uncertainty Sets

  • Vanessa Krebs
  • Martin Schmidt
  • Michael Müller
    • Categories Complementarity and Variational Inequalities, Robust Optimization, Transportation Tags , , ,

    We study uncertain linear complementarity problems (LCPs), i.e., problems in which the LCP vector q or the LCP matrix M may contain uncertain parameters. To this end, we use the concept of Gamma-robust optimization applied to the gap function formulation of the LCP. Thus, this work builds upon [16]. There, we studied Gamma-robustified LCPs for … Read more

    Reformulations for integrated planning of railway traffic and network maintenance

  • Tomas Lidén
  • Hamish Waterer
    • Categories Transportation

    This paper addresses the scheduling problem of coordinating train services and network maintenance windows for a railway system. We present model reformulations, for a mixed integer linear optimization model, which give a mathematically stronger model and substantial improvements in solving performance – as demonstrated with computational experiments on a set of synthetic test instances. As … Read more