A new type of vehicle routing problem （VRP）, multiple vehicle routing problem integrated reverse logistics （MVRPRL）, is studied. In this problem, there is delivery or pickup （or both） and uncertain features in t...A new type of vehicle routing problem （VRP）, multiple vehicle routing problem integrated reverse logistics （MVRPRL）, is studied. In this problem, there is delivery or pickup （or both） and uncertain features in the demands of the clients. The deliveries of every client as uncertain parameters are expressed as triangular fuzzy numbers. In order to describe MVRPRL, a multi-objective fuzzy programming model with credibility measure theory is constructed. Then the simulationbased tabu search algorithm combining inter-route and intra-route neighborhoods and embedded restarts are designed to solve it. Computational results show that the tabu search algorithm developed is superior to sweep algorithms and that compared with handling each on separate routes, the transportation costs can be reduced by 43% through combining pickups with deliveries.展开更多
阐述了一种基于直接搜索模拟退火算法(direct simulated annealing,DSA)和有限元方法(finite element method,FEM)的复合材料层合结构的优化方法。对某型航空发动机机匣质量进行质量优化,优化目标为在保证机匣安全的前提下,尽可能减轻...阐述了一种基于直接搜索模拟退火算法(direct simulated annealing,DSA)和有限元方法(finite element method,FEM)的复合材料层合结构的优化方法。对某型航空发动机机匣质量进行质量优化,优化目标为在保证机匣安全的前提下,尽可能减轻机匣质量,优化变量为铺层数和铺层角度。本文详细阐述了DSA优化方法结合FEM的实施步骤,并提出了一种基于多铺层组的复合材料优化技术。结果表明:DSA优化算法非常有效地减轻了机匣的质量。展开更多
基金The National Natural Science Foundation of China(No.70772059)Youth Science and Technology Innovation Foundation of Nanjing Agriculture University(No.KJ06029)
文摘A new type of vehicle routing problem （VRP）, multiple vehicle routing problem integrated reverse logistics （MVRPRL）, is studied. In this problem, there is delivery or pickup （or both） and uncertain features in the demands of the clients. The deliveries of every client as uncertain parameters are expressed as triangular fuzzy numbers. In order to describe MVRPRL, a multi-objective fuzzy programming model with credibility measure theory is constructed. Then the simulationbased tabu search algorithm combining inter-route and intra-route neighborhoods and embedded restarts are designed to solve it. Computational results show that the tabu search algorithm developed is superior to sweep algorithms and that compared with handling each on separate routes, the transportation costs can be reduced by 43% through combining pickups with deliveries.
文摘阐述了一种基于直接搜索模拟退火算法(direct simulated annealing,DSA)和有限元方法(finite element method,FEM)的复合材料层合结构的优化方法。对某型航空发动机机匣质量进行质量优化,优化目标为在保证机匣安全的前提下,尽可能减轻机匣质量,优化变量为铺层数和铺层角度。本文详细阐述了DSA优化方法结合FEM的实施步骤,并提出了一种基于多铺层组的复合材料优化技术。结果表明:DSA优化算法非常有效地减轻了机匣的质量。
