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861.
张景 《浙江交通职业技术学院学报》2009,10(2):36-42
本文针对配送中心选址的因素进行分析,采用AHP法以及混合整数规划法对配送中心选址进行定性与定量结合的方法进行建模分析。首先由AHP法分析各因素得出最重要的三个因素:运输费用、物流服务需求量、交通条件;然后依照配送中心选址所产生费用最小化的原则来建立采用0~1整数变量的混合整数规划模型。此模型考虑了配送中心固定成本的分摊问题、0—1整数变量及五年规划期的最优,保证选址模型的可行性。提出一个较有效的配送中心选址的方法。 相似文献
862.
针对停车场限制的物流中心选址问题,建立了双层规划模型.上层规划以物流中心费用最小来确定物流中心的位置,下层规划建立了配送/采购车辆与城市道路交通组合分配模型,最后,采用遗传模拟退火算法对模型进行求解. 相似文献
863.
Robust Optimization of Hub-and-Spoke Airline Network Design Based on Multi-Objective Genetic Algorithm 总被引:1,自引:0,他引:1
Jia HUANG Qingyun WANG 《Journal of Transportation Systems Engineering and Information Technology》2009,9(3):86-92
In the process of designing hub network, the selection of hub airports is influenced by the change of the demand and cost. Under the condition of changing in demand, this may lead to large minimum cost deviation between the designed optimal network and real optimal network, respectively. To reduce the risk caused by the uncertainty in network optimization and get the optimal robust solution of hub network under the multi-possible conditions of demand and cost, a method based on multi-objective optimization genetic algorithm is proposed in this paper. The convergence of the algorithm has been proved, and the experimental results demonstrate the availability of the algorithm. First, multiple objective functions needing to be optimized simultaneously are formulated from different conditions of needs and cost, then a genetic algorithm is used to provide all possible routes of the network hub structure, and robust optimal network solution for multi-objective optimization is searched. The convergence of the search algorithms is proved to be effective by the numerical results. 相似文献
864.
���ڶ�Ŀ���Ż��ĵ�·����վ��ѡַ�о� 总被引:1,自引:0,他引:1
为了研究道路客运站场规划的站场选址优化,提出了一种基于多目标优化的道路客运站场选址方法。首先,将道路客运站场规划区域的道路网简化为有向赋权图,使选址优化问题转化为0-1规划问题;然后,以道路客运站场的建设投资、网络总运输成本以及乘客的总出行距离为优化目标,同时把道路客运的实际条件转化为优化目标的约束条件;最后,利用基于目标值排序组合选择的多目标遗传算法求解模型的Pareto最优解集合,并通过客运站场选址优化算例阐述了模型的求解过程。 相似文献
865.
对节点虚流量法进行了改进,严格扣除过渡区中虚流量贡献,使虚流流量的处理在理论上更严密,关键的溢出点位置计算更精细.提出在全部渗流区域的迭代算法,避免了以往算法在迭代过程抛弃虚单元、计算域网格发生变化的做法,从而使算法编程更简单,使用范围更广.算例验证了该算法的正确性和实用性. 相似文献
866.
基于高铁枢纽大规模建设的背景,从规划实践出发,对高铁枢纽社会停车场规模的影响因素进行分析。以济南东客站为例,采用类比法和停车周转率法两种方法,对高铁枢纽的社会停车场规模进行了计算,并给出了推荐值。 相似文献
867.
868.
Determining the number and location of depots for winter road maintenance (WRM) represents one of the important strategic decisions while planning WRM activities. However, most organizations dealing with WRM make empirically based decisions. Optimizing the number and location of WRM depots has the potential to achieve considerable cost savings, improve mobility and efficiency, as well as reduce environmental impacts. This paper presents two optimization models. The first model determines the location of WRM depots by minimizing the total distance travelled by maintenance vehicles. The second model determines the optimum number and location of WRM depots by minimizing total transportation costs and capital expenditure and operational expenditure of the depots. The models are then applied to the district road network in Serbia. Results show that their application could lead to significant reductions in WRM costs. 相似文献
869.
Integration of signal timing estimation model and dynamic traffic assignment in feedback loops: system design and case study 下载免费PDF全文
This paper presents an integrated framework for effective coupling of a signal timing estimation model and dynamic traffic assignment (DTA) in feedback loops. There are many challenges in effectively integrating signal timing tools with DTA software systems, such as data availability, exchange format, and system coupling. In this research, a tight coupling between a DTA model with various queue‐based simulation models and a quick estimation method Excel‐based signal control tool is achieved and tested. The presented framework design offers an automated solution for providing realistic signal timing parameters and intersection movement capacity allocation, especially for future year scenarios. The framework was used to design an open‐source data hub for multi‐resolution modeling in analysis, modeling and simulation applications, in which a typical regional planning model can be quickly converted to microscopic traffic simulation and signal optimization models. The coupling design and feedback loops are first demonstrated on a simple network, and we examine the theoretically important questions on the number of iterations required for reaching stable solutions in feedback loops. As shown in our experiment, the current coupled application becomes stable after about 30 iterations, when the capacity and signal timing parameters can quickly converge, while DTA's route switching model predominately determines and typically requires more iterations to reach a stable condition. A real‐world work zone case study illustrates how this application can be used to assess impacts of road construction or traffic incident events that disrupt normal traffic operations and cause route switching on multiple analysis levels. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
870.