Location of charging stations in electric car sharing systems

Electric vehicles are a prime candidate for use within an urban car sharing system, both from an economic and environmental perspective. However, their relatively short range necessitates frequent and rather time-consuming recharging throughout the day. Thus, charging stations must be built throughout the system’s operational area where cars can be charged between uses. In this … Read more

Tighter MIP Models for Barge Container Ship Routing

This paper addresses the problem of optimal planning of a line for a barge container shipping company. Given estimated weekly splittable demands between pairs of ports and bounds for the turnaround time, our goal is to determine the subset of ports to be called and the amount of containers to be shipped between each pair … Read more

An Effective Dynamic Programming Algorithm for the Minimum-Cost Maximal Knapsack Packing

Given a set of n items with profits and weights and a knapsack capacity C, we study the problem of finding a maximal knapsack packing that minimizes the profit of selected items. We propose for the first time an effective dynamic programming (DP) algorithm which has O(nC) time complexity and O(n+C) space complexity. We demonstrate … Read more

A dual-ascent-based branch-and-bound framework for the prize-collecting Steiner tree and related problems

In this work we present a branch-and-bound (B&B) framework for the asymmetric prize-collecting Steiner tree problem (APCSTP). Several well-known network design problems can be transformed to the APCSTP, including the Steiner tree problem (STP), prize-collecting Steiner tree problem (PCSTP), maximum-weight connected subgraph problem (MWCS) and the node-weighted Steiner tree problem (NWSTP). The main component of … Read more

A polyhedral study of the diameter constrained minimum spanning tree problem

This paper provides a study of integer linear programming formulations for the diameter constrained spanning tree problem (DMSTP) in the natural space of edge design variables. After presenting a straightforward model based on the well known jump inequalities a new stronger family of circular-jump inequalities is introduced. These inequalities are further generalized in two ways: … Read more

A Branch-and-Cut-and-Price Algorithm for Vertex-Biconnectivity Augmentation

In this paper, the first approach for solving the vertex-biconnectivity augmentation problem (V2AUG) to optimality is proposed. Given a spanning subgraph of an edge-weighted graph, we search for the cheapest subset of edges to augment this subgraph in order to make it vertex-biconnected. The problem is reduced to the augmentation of the corresponding block-cut tree, … Read more