17 research outputs found

    Multi-objective Optimization For The Dynamic Multi-Pickup and Delivery Problem with Time Windows

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    The PDPTW is an optimization vehicles routing problem which must meet requests for transport between suppliers and customers satisfying precedence, capacity and time constraints. We present, in this paper, a genetic algorithm for multi-objective optimization of a dynamic multi pickup and delivery problem with time windows (Dynamic m-PDPTW). We propose a brief literature review of the PDPTW, present our approach based on Pareto dominance method and lower bounds, to give a satisfying solution to the Dynamic m-PDPTW minimizing the compromise between total travel cost and total tardiness time. Computational results indicate that the proposed algorithm gives good results with a total tardiness equal to zero with a tolerable cost.Comment: arXiv admin note: text overlap with arXiv:1101.339

    A Comparative Study of the PSO and GA for the m-MDPDPTW

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    The m-MDPDPTW is the multi-vehicles, multi-depots pick-up and delivery problem with time windows. It is an optimization vehicles routing problem which must meet requests for transport between suppliers and customers for the purpose of satisfying precedence, capacity and time constraints. This problem is a very important class of operational research, which is part of the category of NP-hard problems. Its resolution therefore requires the use of evolutionary algorithms such as Genetic Algorithms (GA) or Particle Swarm Optimization (PSO). We present, in this sense, a comparative study between two approaches based respectively on the GA and the PSO for the optimization of m-MDPDPTW. We propose, in this paper, a literature review of the Vehicle Routing Problem (VRP) and the Pick-up and Delivery Problem with Time Windows (PDPTW), present our approaches, whose objective is to give a satisfying solution to the m-MDPDPTW minimizing the total distance travelled. The performance of both approaches is evaluated using various sets instances from [10] PDPTW benchmark data problems. From our study, in the case of m-MDPDPTW problem, the proposed GA reached to better results compared with the PSO algorithm and can be considered the most appropriate model to solve our m-MDPDPTW problem

    Multi-Objective Optimization for the m-PDPTW: Aggregation Method With Use of Genetic Algorithm and Lower Bounds

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    The PDPTW is an optimization vehicles routing problem which must meet requests for transport between suppliers and customers in purpose to satisfy precedence, capacity and time constraints. We present, in this paper, a genetic algorithm for multi-objective optimization of a multi pickup and delivery problem with time windows (m-PDPTW), based on aggregation method and lower bounds. We propose in this sense a brief literature review of the PDPTW, present our approach to give a satisfying solution to the m-PDPTW minimizing the compromise between total travel cost and total tardiness time

    Heuristics optimization for the resolution of the m-PDPTW static and dynamic

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    De nos jours, le problème de transport de marchandise occupe une place importante dans la vie économique des sociétés modernes. Le problème de ramassage et de livraison (pick-up and delivery problem) est l’un des problèmes dont une grande partie des chercheurs s’y est intéressée.Il s’agit de déterminer un circuit de plusieurs véhicules, de façon à servir à coût minimal un ensemble de clients et de fournisseurs répartis dans un réseau, satisfaisant certaines contraintes relatives aux véhicules, à leurs capacités et à des précédences entre les nœuds. Les travaux de recherche développés dans cette thèse portent sur le PDPTW (Pickup and Delivery Problem with Time Windows) à plusieurs véhicules (m-PDPTW). Ce dernier a été traité dans les deux cas : statique et dynamique. Nous avons proposé plusieurs approches de résolution du m-PDPTW basées sur les algorithmes génétiques, l’optimisation multicritère et le calcul des bornes inférieures, et ceci pour minimiser un certain nombre de critères comme : le nombre de véhicules utilisés, la somme des retards ou le coût total de transport. Ces approches ont donné de bons résultats, principalement au niveau de la minimisation de la somme des retards où nous avons obtenu, dans plusieurs cas, un retard nul avec un coût de transport tolérableNowadays, the transport goods problem occupies an important place in the economic life of modern societies. The PDPTW (Pickup and delivery problem with Time Windows) is one which a large part of researchers was interested. This is an optimization vehicles routing problem which must meet requests for transport between suppliers and customers satisfying precedence and capacity.Researchers developed in this thesis concerns the resolution of the PDPTW with multiple vehicles (m-PDPTW). The latter was treated in two cases: static and dynamic.We have proposed some approaches to solving the m- PDPTW, based on genetic algorithms, multicriteria optimization and the lower bounds, and this to minimize a number of criteria such as: the vehicles number, the total travel cost, and the total tardiness time.Computational results indicate that the proposed approach gives good results with a total tardiness equal to zero with a tolerable cos

    Optimisation heuristique pour la résolution du m-PDPTW statique et dynamique

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    Nowadays, the transport goods problem occupies an important place in the economic life of modern societies. The PDPTW (Pickup and delivery problem with Time Windows) is one which a large part of researchers was interested. This is an optimization vehicles routing problem which must meet requests for transport between suppliers and customers satisfying precedence and capacity.Researchers developed in this thesis concerns the resolution of the PDPTW with multiple vehicles (m-PDPTW). The latter was treated in two cases: static and dynamic.We have proposed some approaches to solving the m- PDPTW, based on genetic algorithms, multicriteria optimization and the lower bounds, and this to minimize a number of criteria such as: the vehicles number, the total travel cost, and the total tardiness time.Computational results indicate that the proposed approach gives good results with a total tardiness equal to zero with a tolerable costDe nos jours, le problème de transport de marchandise occupe une place importante dans la vie économique des sociétés modernes. Le problème de ramassage et de livraison (pick-up and delivery problem) est l’un des problèmes dont une grande partie des chercheurs s’y est intéressée.Il s’agit de déterminer un circuit de plusieurs véhicules, de façon à servir à coût minimal un ensemble de clients et de fournisseurs répartis dans un réseau, satisfaisant certaines contraintes relatives aux véhicules, à leurs capacités et à des précédences entre les nœuds. Les travaux de recherche développés dans cette thèse portent sur le PDPTW (Pickup and Delivery Problem with Time Windows) à plusieurs véhicules (m-PDPTW). Ce dernier a été traité dans les deux cas : statique et dynamique. Nous avons proposé plusieurs approches de résolution du m-PDPTW basées sur les algorithmes génétiques, l’optimisation multicritère et le calcul des bornes inférieures, et ceci pour minimiser un certain nombre de critères comme : le nombre de véhicules utilisés, la somme des retards ou le coût total de transport. Ces approches ont donné de bons résultats, principalement au niveau de la minimisation de la somme des retards où nous avons obtenu, dans plusieurs cas, un retard nul avec un coût de transport tolérabl

    Experimental study of the rigidity and transparency to ionizing radiation of composite materials used in the enclosure under pressure of the Micromegas detector

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    Innovation in the field of nuclear imaging is necessarily followed by a radical change in the detection principle. The gas detector Micromegas (Mesh Micro Structure Gaseous) could be an interesting option, thanks to the stability and robustness of such a detector. Thus, it was necessary to study the implementation of the detector enclosure in composite materials. The focus of the present study was the robustness and gamma rays transparency of a set of composites. The studied composites were reinforced with vegetable fibers (alfa), and synthetic fibers. The mechanical properties of all composites specimen were evaluated by three-point bending test, whereas, gamma ray transparency was evaluated by the exposition of composites specimen to a mono-energetic gamma ray beam emitted by a Technetium 99-m source. Findings revealed that the biocomposite materials using alfa fiber and Polymethyl Methacrylate matrix are very promising as long as they present good robustness and high gamma ray transparency in diagnostic range. Keywords: Nuclear imaging, Micromegas detector, Composites, Robustness, Transparency to gamma radiations, Synthetic fibers, Vegetable fiber

    Optimisation heuristique pour la résolution du m-PDPTW statique et dynamique

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    De nos jours, le problème de transport de marchandise occupe une place importante dans la vie économique des sociétés modernes. Le problème de ramassage et de livraison (pick-up and delivery problem) est l un des problèmes dont une grande partie des chercheurs s y est intéressée.Il s agit de déterminer un circuit de plusieurs véhicules, de façon à servir à coût minimal un ensemble de clients et de fournisseurs répartis dans un réseau, satisfaisant certaines contraintes relatives aux véhicules, à leurs capacités et à des précédences entre les nœuds. Les travaux de recherche développés dans cette thèse portent sur le PDPTW (Pickup and Delivery Problem with Time Windows) à plusieurs véhicules (m-PDPTW). Ce dernier a été traité dans les deux cas : statique et dynamique. Nous avons proposé plusieurs approches de résolution du m-PDPTW basées sur les algorithmes génétiques, l optimisation multicritère et le calcul des bornes inférieures, et ceci pour minimiser un certain nombre de critères comme : le nombre de véhicules utilisés, la somme des retards ou le coût total de transport. Ces approches ont donné de bons résultats, principalement au niveau de la minimisation de la somme des retards où nous avons obtenu, dans plusieurs cas, un retard nul avec un coût de transport tolérableNowadays, the transport goods problem occupies an important place in the economic life of modern societies. The PDPTW (Pickup and delivery problem with Time Windows) is one which a large part of researchers was interested. This is an optimization vehicles routing problem which must meet requests for transport between suppliers and customers satisfying precedence and capacity.Researchers developed in this thesis concerns the resolution of the PDPTW with multiple vehicles (m-PDPTW). The latter was treated in two cases: static and dynamic.We have proposed some approaches to solving the m- PDPTW, based on genetic algorithms, multicriteria optimization and the lower bounds, and this to minimize a number of criteria such as: the vehicles number, the total travel cost, and the total tardiness time.Computational results indicate that the proposed approach gives good results with a total tardiness equal to zero with a tolerable costVILLENEUVE D'ASCQ-ECLI (590092307) / SudocSudocFranceF
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