Numerous communication networks are emerging to serve the various demands and improve quality of service. Heterogeneous users have different requirements on metrics such as delay service efficiency. Besides, equipped with types amounts resources, how efficiently optimize usage limited resources more is key issue for networks. One powerful mathematical optimization mechanism solve above column g...

The Split Delivery Vehicle Routing Problem (SDVRP) allows customers to be assigned to multiple routes. A column generation procedure using a route-based formulation is developed for the SDVRP and computational results are given for thirty-two data sets from previous literature. The SDVRP route-based formulation appears tighter (stronger) linear relaxation than a comparable SDVRP flow formulatio...

We present a model for the vehicle and crew scheduling problem in urban public transport systems by combining models for vehicle and crew scheduling that cover a great variety of real world aspects, especially constraints for crews resulting from wage agreements and internal regulations. The main part of the model consists of a set partitioning formulation to cover the desired trips of the sche...

The Split Delivery Vehicle Routing Problem (SDVRP) allows customers to be assigned to multiple routes. A column generation procedure using a route-based formulation is developed for the SDVRP and computational results are given for thirty-two data sets from previous literature. The SDVRP route-based formulation appears tighter (stronger) linear relaxation than a comparable SDVRP flow formulatio...

We present a combined use of Genetic Algorithms (GAs) and column generation to approximately solve graph-coloring problems. The proposed method is divided in two phases. The constructive phase builds the initial pool of columns using a Constructive Genetic Algorithm (CGA). Each column forms an independent set. The second phase solves by column generation the set covering formulation. The column...