This thesis considers two NP hard generalized network design problems, where the nodes of a graph are partitioned into clusters and exactly one node from each cluster must be connected. The objective of both problems is to identify for a given graph a subgraph with minimal total edge costs and satisfying certain constraints. The Generalized Minimum Spanning Tree (GMST) problem extends the classical Minimum Spanning Tree problem by seeking a connected cycle-free subgraph containing exactly one… CONTINUE READING