Edward Lam

Optimal Multi-Agent Pickup and Delivery Using Branch-and-Cut-and-Price

  • Edward Lam
    • Categories Branch and Cut Algorithms, Integer Programming, Transportation

    Given a set of agents and a set of pickup-delivery requests located on a two-dimensional map, the Multi-Agent Pickup and Delivery problem assigns the requests to the agents such that every agent moves from its start location to the locations of its assigned requests and finally to its end location without colliding into any other … Read more

    Branch-and-cut-and-price for the Cardinality-constrained Multi-cycle Problem in Kidney Exchange

  • Edward Lam
  • Vicky Mak-Hau
    • Categories Biomedical Applications, Branch and Cut Algorithms, Graphs and Matroids Tags , , , , , , ,

    The establishment of kidney exchange programs has dramatically improved rates for kidney transplants by matching donors to compatible patients who would otherwise fail to receive a kidney for transplant. Rather than simply swapping kidneys between two patient-donor pairs, having multiple patient-donors pairs simultaneously donate kidneys in a cyclic manner enables all participants to receive a … Read more

    Branch-and-Cut-and-Price for Multi-Agent Pathfinding

  • Daniel Harabor
  • Edward Lam
  • Pierre Le Bodic
  • Peter J. Stuckey
    • Categories 0-1 Programming, Branch and Cut Algorithms, Transportation Tags , , , ,

    There are currently two broad strategies for optimal Multi-agent Pathfinding (MAPF): (1) search-based methods, which model and solve MAPF directly, and (2) compilation-based solvers, which reduce MAPF to instances of well-known combinatorial problems, and thus, can benefit from advances in solver techniques. In this work, we present an optimal algorithm, BCP, that hybridizes both approaches … Read more