In this document, I outline a few challenging algorithmic problems arising in my research on optimal transportation. I have attempted to pose these problems in “discrete” language. It easily could be the case that they admit straightforward solutions— which is great news!—or that you can do little more than the obvious algorithm. Any and all guidance from members of the theory community is welc...

When solving hard multicommodity network flow problems using an LP-based approach, the number of commodities is a driving factor in speed at which LP can be solved, as it linear constraints and variables. The conventional approach to improve solve time relaxation Mixed Integer Programming (MIP) model that encodes such instance aggregate all have same origin or destination. However, bound result...

Multi-modal transportation is a logistics problem in which a set of goods have to be transported to different places, with the combination of at least two modes of transport, without a change of container for the goods. The goal of this paper is to describe TIMIPLAN, a system that solves multi-modal transportation problems in the context of a project for a big company. In this paper, we combine...

In this paper, we consider the problem of managing a fleet of trucks with different capacity to serve the requests of different customers that arise randomly over time. Customers make a request by demanding the transportation of a given quantity of goods from an origin to a destination, at a given time. It is well known that these problems arise in the dynamic resource allocation context, where...

A new polynomial formulation of variable step size linear multistep methods is presented, where each k-step method is characterized by a fixed set of k− 1 or k parameters. This construction includes all methods of maximal order (p = k for stiff, and p = k+1 for nonstiff problems). Supporting time step adaptivity by construction, the new formulation is not based on extending classical fixed step...