The parallel execution of branch and bound algorithms can result in seemingly unreasonable speedups or slowdowns. Almost never the speedup is equal to the increase in computing power. For synchronous parallel branch and bound, these effects have been studied extensively. For asynchronousparallelizations, only little is known. In this paper, we derive… (More)
In the last decade many models for parallel computation have been proposed and many parallel algorithms have been developed. However, few of these models have been realized and most of these algorithms are supposed to run on idealized, unrealistic parallel machines. The parallel machines constructed so far all use a simple model of parallel computation.… (More)
Many (parallel) branch and bound algorithms look very different from each other at first glance. They exploit, however, the same underlying computational model. This phenomenon can be used to define branch and bound algorithms in terms of a set of basic rules that are applied in a specific (predefined) order. In the sequential case, the specification of… (More)
In memory ofPaolo Camerini Local search is a well-known and a well·investigated solution approach for the traveling salesman problem. It is not obvious, however, how local search for the TSP has to be implemented efficiently when each city has to be visited within one or more given time windows.1bis is particularly true when parallel computer architectures… (More)
Dit proefschrift is goedgekeurd door de promotor: Acknowledgements The process of writing this thesis has been completed successfully thanks to numerous people. Especially, I would like to thank Steef van de Velde, who helped me to get acquainted with scientific research and who conducted joint research with me. I also would like to thank Gerard… (More)
In this paper we will describe a Multi-Agent System which is capable of finding a feasible solution of a specially structured linear programming problem. Emphasis is given to correctness issues and termination detection.