Connections in Networks: A Hybrid Approach

This paper extends our previous work by exploring the use of a hybrid solution method for solving the connection subgraph problem. We employ a two phase solution method, which drastically reduces the cost of testing for infeasibility and also helps prune the search space for MIP-based optimization. Overall, this provides a much more scalable solution than simply optimizing a MIP model of the problem with Cplex. We report results for semi-structured lattice instances as well as on real data used for the construction of a wildlife corridor for grizzly bears in the Northern Rockies region. In recent work [2], we investigated the connection subgraph problem, which seeks to identify a cost bounded connected subgraph of a given undirected graph connecting certain pre-specified terminal nodes, while maximizing the overall utility. Here costs and utilities are non-negative numbers assigned to each node of the graph, and the cost (or utility) of a subgraph is the sum of the costs (utilities, re...

• Type: Conference
• Year: 2008
• Where: CPAIOR
• Authors: Carla P. Gomes, Willem Jan van Hoeve, Ashish Sabharwal
• Keywords: Connection Subgraph Problem, CPAIOR 2008, Infeasible Instances, Operations Research, Solution Method