共查询到20条相似文献,搜索用时 375 毫秒
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提出了应用于船舶初步设计的多目标优化策略和决策方法.详细介绍了集成模型分析和优化算法的多目标优化求解思路,并使用改进的非支配排序遗传算法获取优化问题的Pareto解集.针对多目标优化问题中各子目标之间存在相互冲突、不能同时达到最优的特性,采用多属性决策理论对设计空间进行计算分析,找出.Pareto前沿面上的最优解.以散货船的初步设计为实例,对多目标优化策略和决策方法进行了验证分析.结果表明优化策略和决策方法不仅是可靠的、实用的,而且能广泛应用于各类船舶初步设计的优化与决策分析中.该文为船舶的初步设计提供了一条新途径. 相似文献
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基于组合赋权TOPSIS法和粒子群的船舶概念优化设计 总被引:1,自引:1,他引:0
船舶概念设计阶段,需要初步给定多组船型参数方案并从中优选出客观合理的某一方案。本文建立以船舶造价、螺旋桨总效率、相对回转直径为目标的船舶概念设计优化数学模型。将Li提出的最小-最大适应度多目标粒子群优化算法应用于求解船舶概念设计多目标问题以获得Pareto解集。分析主观赋权和客观赋权的优劣,提出借鉴专家经验和信息熵权的主客观组合赋权TOPSIS法,借助Matlab软件对所求Pareto解集进行方案排序。算例表明,maximinPSO在求解35 000 DWT散货船概念设计多目标优化能获得均匀分布的Pareto前沿,基于组合赋权的TOPSIS策略能给出客观、合理的决策序列。该方法可应用于船舶优化等领域。 相似文献
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针对集装箱船配载优化中的Bay位优选问题,提出以倒箱量、重心横向偏移和初稳性高为目标,以箱位与Bay位的一致和Bay位重量为约束条件的数学模型,提出一种多目标离散粒子群算法(MODPSO)求解之,得到该算法优化后的Pareto解集和Pareto解迭代过程中的变化趋势图,为集装箱船配载问题提供多种方案以供备选,从而达到在提高集装箱船装载效率、节约装载成本和时间、使集装箱船获得稳定航行状态等目标间取得更好平衡的目的。 相似文献
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针对多学科多目标设计优化存在的耦合严重、计算效率低、难以获得体现设计者使用要求的最优解等问题,提出了基于自适应加权的多学科多目标设计优化方法,阐述了该方法的基本思想并给出了设计优化流程.该方法密切结合实际工程设计经验,将多目标优化问题转换为反映设计者使用要求的综合目标优化问题,采用自适应加权的优化策略建立优化模型进行优... 相似文献
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船体结构静动态协同优化设计(英文) 总被引:4,自引:0,他引:4
论文集成静态、模态和动力响应分析,建立了船体结构静、动态协同优化模型.在系统级优化模型中,以单学科最优解和多学科最优解之间的差异最小化为目标.该目标函数不仅消除了多个目标之间的量纲和数量级差异的影响,而且扩展了协同优化算法的应用范围,由原来的单目标优化扩展到了多目标优化.并与子系统级优化模型构成二级协同优化算法架构.采用多岛遗传算法进行优化求解.对集装箱船艉主甲板进行了静、动态优化设计,分析表明本文所采用的优化算法能应用于工程实际. 相似文献
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Kjetil Fagerholt 《Maritime Policy and Management》2000,27(2):145-153
In many ship scheduling problems, time windows are imposed at the loading and/ or discharging of the cargoes to be lifted. Up until now, all proposed solution methods to ship scheduling problems have treated the time window constraints as hard constraints. By transforming the time window constraints into soft constraints, some of the loading/discharging operations may be performed outside the time windows, penalized by an inconvenience cost for not meeting the time window. The motivation behind introducing soft time windows is that, by allowing controlled time window violations for some customers, it may be possible to obtain better routes and significant reductions in the transportation costs. The purpose of this paper is to evaluate the trade-off between transportation costs and the time window violations. Computational results based on data from a real ship scheduling problem are presented and used as a basis for the evaluation. 相似文献
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Kjetil Fagerholt 《Maritime Policy and Management》2013,40(2):145-153
In many ship scheduling problems, time windows are imposed at the loading and/ or discharging of the cargoes to be lifted. Up until now, all proposed solution methods to ship scheduling problems have treated the time window constraints as hard constraints. By transforming the time window constraints into soft constraints, some of the loading/discharging operations may be performed outside the time windows, penalized by an inconvenience cost for not meeting the time window. The motivation behind introducing soft time windows is that, by allowing controlled time window violations for some customers, it may be possible to obtain better routes and significant reductions in the transportation costs. The purpose of this paper is to evaluate the trade-off between transportation costs and the time window violations. Computational results based on data from a real ship scheduling problem are presented and used as a basis for the evaluation. 相似文献
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船舶航行性能优化是一个非常复杂的问题,它具有多个设计变量,多个约束和多个极点.传统的优化方法通常无法解决该问题.文中采用了一种传统的优化方法一复合形法(CA)和遗传算法(GA),模拟退火算法(SA)来计算船舶航行性能优化问题,比较了三种优化方法的输出结果并选取最好的那个解作为最终的优化结果.通过这种方法.可以以更高的概率获得真实的最优解.应该指出的是,这三种算法都作了某种程度上的改进.作者采用C++语言基于面向对象思想开发了计算软件-ShipPO.文中列出的所有船舶航行性能优化计算结果都是在ShipPO平台上计算出来的,结果表明采用三种优化方法计算一次船舶航行性能优化问题耗时并不太多.最终的结果表明ShipPO具有很强的寻找全局最优解的能力,它能够很好地满足工程需要. 相似文献
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This paper deals with a realistic multi-period liner ship fleet planning problem by incorporating stochastic dependency of the random and period-dependent container shipment demand. This problem is formulated as a multi-period stochastic programming model with a sequence of interrelated two-stage stochastic programming (2SSP) problems characterized ship fleet planning in each single period. A solution method integrating dual decomposition and Lagrangian relaxation method is designed for solving the developed model. Numerical experiments are carried out to assess applicability and performance of the proposed model and solution algorithm. The results further demonstrate importance of stochastic dependence of the uncertain container shipment demand. 相似文献
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Zbigniew Sekulski 《Marine Structures》2010,23(4):405-433
Ship structural design has become recently an ever more important and difficult task, because it should always take into account several estimation criteria which are a crucial element of shipyard management, as the hull structural strength is one of the most important factors of overall ship safety, and the total cost of structural materials used for the construction of a ship is a significant part of her total construction cost. Simultaneously, a complete definition of the optimal structural design requires a formulation of size-topology-shape-material optimization task unifying the optimization problems from these four areas and giving an effective solution of this problem. So far, a significant progress towards a solution of this problem has not been achieved. An objective of the underlying paper was to develop an evolutionary algorithm for multi-objective optimization of both topology and scantlings of structural elements of large spatial sections of ships. In the paper an evolutionary algorithm where selection takes place based on the scalar objective function is proposed and applied to solve the problem of structural elements weight and cleaned and painted surface area on a high-speed vehicle-passenger catamaran structure with several design variables, such as plate thickness, scantlings of longitudinal stiffeners and transverse frames, and spacing between longitudinal and transversal members. The results of numerical experiments with the use of the developed algorithm are presented. They show that the proposed genetic algorithm can be an efficient multi-objective optimization tool for simultaneous design of the topology and sizing of ship structures. 相似文献