The Steiner tree problem aims to determine a minimum edge-weighted tree spanning a given set of terminal vertices from a given graph. As a popular model for numerous practical applications, the problem has been the object of two important competitions (the 11th DIMACS Challenge in 2014 and the...

The generalized independent set problem (GIS) is a generalization of the classical maximum independent set problem and has various practical applications, such as forest harvesting and image/video processing. In this work, we present highly effective exact and heuristic algorithms for the GIS....

This paper presents an extraction and expansion approach for the graph coloring problem. The extraction phase transforms a large graph into a sequence of progressively smaller graphs by removing large independent sets from the graph. The expansion phase starts by generating an approximate...

Given an undirected graph G=(V,E) with a set V of vertices and a set E of edges, the graph coloring problem consists of partitioning all vertices into k independent sets and the number of used colors k is minimized. This paper presents a memetic algorithm (denoted by MACOL) for solving the...