共查询到17条相似文献,搜索用时 62 毫秒
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一种部分约束满足车辆路线问题及其求解算法 总被引:1,自引:0,他引:1
描述了一类过度约束车辆路线问题,其中可用车辆数较少而时间窗口等其它约束又不允许放松,因而导致不存在满足所有约束的可行解。此时问题求解可以转化为一类部分约束满足问题来处理,相应的优化目标是最小化未访问顾客的损失和。本给出了求解这类特殊问题的一种禁忌搜索算法设计,并通过规模不同的几个算例与其它常用方法进行了比较。最后分析了模型和算法的实用意义。 相似文献
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多车场有时间窗的多车型车辆调度及其禁忌算法研究 总被引:12,自引:0,他引:12
本文针对物流配送中的多车场车辆调度问题提出了两种多车场的处理方法,介绍了多车场车辆调度问题中容量、时间窗、多车型等多种约束的处理方法,并且根据具体约束情况设计了禁忌算法,对多车场有时间窗的多车型车辆调度问题加以实现,给出了一个具有代表性的算例试验结果和结果分析,通过试验表明了此方法对优化有时间窗的多车型车辆调度问题的有效性. 相似文献
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时间窗变动的车辆调度干扰管理模型与算法 总被引:1,自引:0,他引:1
针对客户时间窗变动对原物流配送车辆调度方案造成干扰的问题,运用干扰管理思想,分析干扰事件对路径、成本和服务时间三个方面的影响,对其干扰程度加以度量;以该干扰事件对原方案造成的广义费用偏离最小为目标,建立客户时间窗变动的干扰管理模型,通过判断客户时间窗变动对原方案是否产生影响进行干扰辨识,并基于该干扰辨识结果,设计基于禁忌搜索新的调度算法;算例不仅验证了模型和算法的有效性,而且,敏感性分析也验证了其对各种不同价值货物的适用性。实验结果表明,本文提出的干扰管理模型可以全面地刻画干扰对原方案的影响,干扰处理方法优于全局重调度方法,且能够在更短时间内生成满意的物流配送车辆调度调整方案。 相似文献
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《数学的实践与认识》2020,(3)
为了求解带容量约束的车辆路径问题,提出了一种混合教与学优化算法.该算法基于标准的教与学算法,结合基于禁忌搜索算法的局部优化方法,力求进一步强化标准教与学算法的寻优能力.最后通过引入标准数据集,进行了仿真实验并给出了实验分析,测试结果验证了构建的混合教与学优化算法相比其他三种优化算法搜索性能较强,与最优解偏差最小,能够有效地应对离散优化问题. 相似文献
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基于混合算法的实时订货信息下的车辆调度优化 总被引:2,自引:0,他引:2
实时订货信息下的车辆调度是随机性车辆调度中货物需求量、需求点均不确定的情况下的车辆调度.针对该问题,本文构建了配送总成本最小的目标函数,提出了采用混合算法求解的思路.即以局部搜索法求得初始解,采用遗传算法优化初始解,并在送货时间更新后,利用禁忌搜索法求解速度快的特点改进调度方案,得到订货信息不断更新的条件下的车辆调度方案.通过实例分析,本方法既可解决电子商务条件下实时订货的车辆调度问题,也具有求解结果可靠、求解过程快速的特点. 相似文献
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《数学的实践与认识》2015,(7)
针对传统车辆路径问题片面强调行驶里程最短的弊端,引入客户满意度目标,提出了基于客户满意度的车辆路径问题数学模型,并通过线性加权将多目标模型转化为单目标.使用蚁群算法求解模型,并在蚂蚁状态转移中引入时间窗宽度因素,以优先考虑那些具有时间紧迫性的客户.对Solomon案例的实验仿真,结果表明了模型的合理性和算法的高效性. 相似文献
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In real life distribution of goods, relatively long service times may make it difficult to serve all requests during regular working hours. These difficulties are even greater if the beginning of the service in each demand site must occur within a time window and violations of routing time restrictions are particularly undesirable. We address this situation by considering a variant of the vehicle routing problem with time windows for which, besides routing and scheduling decisions, a number of extra deliverymen can be assigned to each route in order to reduce service times. This problem appears, for example, in the distribution of beverage and tobacco in highly dense Brazilian urban areas. We present a mathematical programming formulation for the problem, as well as a tabu search and an ant colony optimization heuristics for obtaining minimum cost routes. The performance of the model and the heuristic approaches are evaluated using instances generated from a set of classic examples from the literature. 相似文献
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Arild Hoff Irina Gribkovskaia Gilbert Laporte Arne Løkketangen 《European Journal of Operational Research》2009
This paper considers the vehicle routing problem with pickups and deliveries (VRPPD) where the same customer may require both a delivery and a pickup. This is the case, for instance, of breweries that deliver beer or mineral water bottles to a set of customers and collect empty bottles from the same customers. It is possible to relax the customary practice of performing a pickup when delivering at a customer, and postpone the pickup until the vehicle has sufficient free capacity. In the case of breweries, these solutions will often consist of routes in which bottles are first delivered until the vehicle is partly unloaded, then both pickup and delivery are performed at the remaining customers, and finally empty bottles are picked up from the first visited customers. These customers are revisited in reverse order, thus giving rise to lasso shaped solutions. Another possibility is to relax the traditional problem even more and allow customers to be visited twice either in two different routes or at different times on the same route, giving rise to a general solution. This article develops a tabu search algorithm capable of producing lasso solutions. A general solution can be reached by first duplicating each customer and generating a Hamiltonian solution on the extended set of customers. Test results show that while general solutions outperform other solution shapes in term of cost, their computation can be time consuming. The best lasso solution generated within a given time limit is generally better than the best general solution produced with the same computing effort. 相似文献
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李全亮 《数学的实践与认识》2008,38(15)
对带时间窗的车辆路径问题(VRPTW)的求解分为两个过程,先由遗传算法求解出初步的可行解,由此生成信息素初始分布,而后采用蚂蚁算法找出问题的最优解或近似最优解.通过具体算例,从数值计算上探索了遗传算法和蚂蚁算法融合后的优化能力,获得了满意的效果. 相似文献
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