Abstract
AbstractIn this paper we propose two cooperation schemes to compose new parallel variants of the Variable Neighborhood Search (VNS). On the one hand, a coarse-grained cooperation scheme is introduced which is well suited for being enhanced with a solution warehouse to store and manage the so far best found solutions and a self-adapting mechanism for the most important search parameters. This makes an a priori parameter tuning obsolete. On the other hand, a fine-grained scheme was designed to reproduce the successful properties of the sequential VNS. In combination with the use of parallel exploration threads all of the best solutions and 11 out of 20 new best solutions for the Multi Depot Vehicle Routing Problem with Time Windows were found.
Highlights
In recent years, cluster and grid architectures have become more and more popular
The aim of this paper is twofold: First, we propose a cooperative and adaptive algorithm based on the philosophy of the Variable Neighborhood Search (VNS)
In the coarse-grained cooperation scheme exactly one ascending move is performed per thread, i.e. at least 2 · a iterations are made between communications
Summary
Cluster and grid architectures have become more and more popular. These architectures enable the design and development of cooperating algorithms to solve complex problems in the field of combinatorial optimization more efficiently than their sequential counterparts. The aim of this paper is twofold: First, we propose a cooperative and adaptive algorithm based on the philosophy of the Variable Neighborhood Search (VNS) This metaheuristic described by Hansen and Mladenovic (1999) is applied to solve Multi. For the p-median problem, a cooperative implementation ofthe VNS was recently developed (e.g., Crainic, Gendreau, Hansen, and Mladenovic 2004 ; Garcia Lopez, Melian Batista, Moreno Perez, and Moreno Vega 2002). Some papers on the parallelization of algorithms for solving the capacitated vehicle routing problem have been published (e.g., Jozefowiez, Semet, and Taibi 1999, 2005; Ralphs 2004). The second approach called Replicated Parallel VNS (RPVNS) and described by Crainic, Gendreau, Hansen, and Mladenovic (2004) runs an independent VNS procedure on each processor.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
