共查询到18条相似文献,搜索用时 46 毫秒
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针对传统数学规划方法处理BRT网络系统优化存在的局限性,提出了一类直达乘客量最大化的BRT网络规划问题并建立了数学模型。设计了该优化模型的禁忌算法。多次仿真实验结果表明模型合理,算法有效。 相似文献
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为提高需求响应公交(DRT)系统的运行效率,针对目前DRT线路与线路之间运营相对独立的现实问题,提出一种面向多车协同的DRT网络化运营新模式,通过多个车辆间的协同调度,实现其路径与时刻表的同步优化。在此模式下,以最小化系统成本为目标,考虑乘客出行时间偏好等约束条件,构建DRT网络化运营优化模型。针对模型求解难点,设计了改进的变邻域搜索算法,通过构造不同规模算例验证算法的有效性,并应用实际案例进行分析。结果表明:相较于传统非网络化运营模式,采用网络化运营策略可以显著降低系统总成本,节约最高可达42.67%,同时可以有效缩短车辆的运行时间61.9%,能够为DRT运营优化问题提供参考。 相似文献
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以往对需求响应型公交的研究中,鲜有考虑到时变路网、碳排放等因素对车辆调度的影响,需要对现有研究的局限性进行改进。针对当前“双碳”背景下存在传统燃油公交与电动公交混合运行的现状,结合两者特性分别给出约束条件、成本和碳排放测算方法,建立包含延误时间、碳排放和运营成本作为优化目标的调度优化模型,并提出了自适应遗传-萤火虫算法用以求解该模型。实验结果表明:a)所提算法改善了传统遗传算法中易陷入局部最优的问题,在基于仿真路网的实验中能使目标函数减少9.1%,平均车辆使用数、平均途经节点数和平均行驶里程数分别减少了0.3辆、4.9个和104.57 km,提高了求解精度;b)模型考虑碳排放影响最高能减少9%的碳排放量,运营成本降低2.9%;c)动态阻抗下的车辆调度方案既贴近实际情况,又能同时降低7.5%的碳排放以及节约5%的运营成本;d)电动公交的引入能得到显著的碳减排效果,但由此带来的成本上升也是不容忽视的。 相似文献
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基于ZigBee的城市智能公交网络系统 总被引:5,自引:0,他引:5
提出一种新型的智能公交系统。该系统基于分布式ZigBee网络,能够以较低的成本实现全部线路车辆的定位和预报功能,同时具有高可靠性和易扩展性。ZigBee是一种新兴的自动路由短距无线网络通信技术,但由于其管理网络范围有限,无法直接用于整个城市公交线路。本文以划分区域和边界路由的方式解决了上述问题,给出了区域化的网络结构和系统的软硬件设计方案。 相似文献
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针对目前高铁票价单一、客运收益率低、区段客流不均衡等问题,提出基于客流分配的高铁票价调整策略。首先,分析影响旅客出行选择行为的相关因素,构建包含经济性、快速性、便捷性和舒适性四项指标的广义出行费用函数;然后,建立兼顾高铁客运管理部门收益最大化和旅客出行费用最小化的双层规划模型,其中上层规划通过制定票价调整策略实现高铁客运收益最大化,下层规划以旅客广义出行费用最小为目标,利用区段不同车次间的竞合关系构建随机用户均衡(SUE)分配模型,同时采用基于改进Logit分配模型的相继平均法(MSA)进行求解;最后,结合案例验证了所提票价调整策略能够有效地平衡区段客流,降低旅客出行成本并在一定程度上提高客运收益。结果分析表明该票价调整策略能够为铁路客运管理部门优化票价体系、制定票价调整方案提供决策支持与方法指导。 相似文献
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为解决目前交通分配模型仅限于某种方式内,并缺少考虑方式划分与交通分配相互影响的问题,描述了多方式复合城市交通网络。网络中涵盖了公交车和小汽车两个子系统,出行总量满足弹性需求,并根据两个子系统效用函数进行随机用户平衡分配,同时子系统内各路径流量分配也满足随机用户平衡,从而建立了两层次三随机用户平衡的多方式复合城市交通网络弹性需求随机用户平衡分配模型。证明了模型解的等价性及唯一性;提出了综合对角化算法和MSA算法的组合求解算法。最后,设计了一个算例以验证模型有效性,计算结果为:公交车出行量为814.1人次/h,占总出行量3997.8人次/h的20.36%,小汽车出行量占79.64%。表明该模型在计算网络中各路段流量的同时,也可得出各交通方式的比重。 相似文献
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孙超 《计算机应用与软件》2025,(1):49-54+101
针对多OD需求响应型公交线路优化问题,综合考虑服务时间窗、运营费用、乘客选择,构建线路优化双层规划模型;上层模型以运营总成本最小为目标,下层采用用户均衡交通分配模型;设计贪心算法求解模型可行解,采用混合粒子群算法针对可行解求出相对最优解。用小型案例证明,求解方法能够求出更加符合公交实际运营的方案,求解算法质量方面,与遗传算法求出的结果相比,总运营里程数减少了3公里,总运营费用减少了146.9元,运算时间减少了17 s,能有效优化公交线路方案。 相似文献
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The length of journey towards a bus stop or railway station greatly influences passenger satisfaction and, thus, the utilization of public transport offers. In this context, we investigate the maximum covering location problem in networks (MCLPN) where stops (or stations) are to be located in a given railway or bus network, such that the number of passengers reaching a stop within their particular coverage radius is maximized. Up to now, no specialized solution procedure directly addressing MCLPN exists, instead it is mainly referred to the well-known maximum covering location problem (MCLP), which, however, neglects the underlaying information of the given network structure. This paper exploits the network information, introduces a fast and efficient two-stage dynamic programming based heuristic specifically tailored to MCLPN, and compares it to existing procedures for MCLP. The results show that our heuristic delivers near optimal solutions, i.e., 87% of our test instances are solved to optimality, within a few seconds of computational time. 相似文献
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Yibing Lv Tiesong Hu Guangmin Wang Zhongping Wan 《Computers & Mathematics with Applications》2008,55(12):2823-2829
A neural network model is presented for solving nonlinear bilevel programming problem, which is a NP-hard problem. The proposed neural network is proved to be Lyapunov stable and capable of generating approximal optimal solution to the nonlinear bilevel programming problem. The asymptotic properties of the neural network are analyzed and the condition for asymptotic stability, solution feasibility and solution optimality are derived. The transient behavior of the neural network is simulated and the validity of the network is verified with numerical examples. 相似文献
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针对目前我国城市公交查询系统存在的不足,提出了一种便于乘客进行路线选择的最少换乘算法,并探讨了以换乘次数最少为目标的公交查询方案。该方案通过可视化界面,为乘客提供公交站点、车次、线路设置等信息;当乘客在输入车次或站点后,系统自动为乘客提供相应的线路信息和最佳乘车方案。试验结果证明该方案是可行的、有效的。面对今后越来越复杂化的城市交通,该自动查询系统和最佳乘车方案将为城市交通网络的发展奠定一定的基础。 相似文献
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求解二层规划的混合微粒群算法 总被引:1,自引:0,他引:1
对于二层规划问题有许多经典的求解方法,如极点搜索法、分支定界法和罚函数法等。文中给出了基于微粒群算法的二层规划的一种新的求解方法。提出了分别先用单纯形法和内部映射牛顿法的子空间置信域法求解下层规划,然后用微粒群算法求解上层规划的求解方法,这两种混合微粒群算法分别用于求解线性二层规划和非线性二层规划。并结合实例的对比分析,说明了这两种混合微粒群算法求解二层规划的可行性和有效性。 相似文献
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Within the framework of any bilevel decision problem, a leader’s decision is influenced by the reaction of his or her follower. When multiple followers who may have had a share in decision variables, objectives and constraints are involved in a bilevel decision problem, the leader’s decision will be affected, not only by the reactions of these followers, but also by the relationships among these followers. This paper firstly identifies nine different kinds of relationships (S1 to S9) amongst followers by establishing a general framework for bilevel multi-follower decision problems. For each of the nine a corresponding bilevel multi-follower decision model is then developed. Also, this paper particularly proposes related theories focusing on an uncooperative decision problem (i.e., S1 model), as this model is the most basic one for bilevel multi-follower decision problems over the nine kinds of relationships. Moreover, this paper extends the Kuhn-Tucker approach for driving an optimal solution from the uncooperative decision model. Finally, a real case study of a road network problem illustrates the application of the uncooperative bilevel decision model and the proposed extended Kuhn-Tucker approach. 相似文献
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Mir Ehsan Hesam Sadati Deniz Aksen Necati Aras 《International Transactions in Operational Research》2020,27(2):835-866
The protection of critical facilities has been attracting increasing attention in the past two decades. Critical facilities involve physical assets such as bridges, railways, power plants, hospitals, and transportation hubs among others. In this study we introduce a bilevel optimization problem for the determination of the most critical depots in a vehicle routing context. The problem is modeled as an attacker–defender game (Stackelberg game) from the perspective of an adversary agent (the attacker) who aims to inflict maximum disruption on a routing network. We refer to this problem as the r‐interdiction selective multi‐depot vehicle routing problem (RI‐SMDVRP). The attacker is the decision maker in the upper level problem (ULP) who chooses r depots to interdict with certainty. The defender is the decision maker in the lower level problem (LLP) who optimizes the vehicle routes in the wake of the attack. The defender has to satisfy all customer demand either using the remaining depots or through outsourcing to a third party logistics service provider. The ULP is solved through exhaustive enumeration, which is viable when the cardinality of interdictions does not exceed five among nine depots. For the LLP we implement a tabu search heuristic adapted to the selective multi‐depot VRP. Our results are obtained on a set of RI‐SMDVRP instances synthetically constructed from standard MDVRP test instances. 相似文献
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We consider a continuous multi-facility location-allocation problem that aims to minimize the sum of weighted farthest Euclidean distances between (closed convex) polygonal and/or circular demand regions, and facilities they are assigned to. We show that the single facility version of the problem has a straightforward second-order cone programming formulation and can therefore be efficiently solved to optimality. To solve large size instances, we adapt a multi-dimensional direct search descent algorithm to our problem which is not guaranteed to find the optimal solution. In a special case with circular and rectangular demand regions, this algorithm, if converges, finds the optimal solution. We also apply a simple subgradient method to the problem. Furthermore, we review the algorithms proposed for the problem in the literature and compare all these algorithms in terms of both solution quality and time. Finally, we consider the multi-facility version of the problem and model it as a mixed integer second-order cone programming problem. As this formulation is weak, we use the alternate location-allocation heuristic to solve large size instances. 相似文献
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In this paper, a constraint set swelling homotopy (CSSH) algorithm for solving the single-level non-convex programming problem with designing piecewise linear contractual function which is equivalent to the principal-agent model with integral operator is proposed, and the existence and global convergence is proven under some mild conditions. As a comparison, a piecewise constant contract is also designed for solving the single-level non-convex programming problem with the corresponding discrete distributions. And some numerical tests are done by the proposed homotopy algorithm as well as by using fmincon in Matlab, LOQO and MINOS. The numerical results show that the CSSH algorithm is robust, feasible and effective. 相似文献