针对铁路12306用户订单取消行为的研究

通过对铁路12306用户频繁出现取消交易操作现象及其产生原因的分析,提出了相关的解决方案,旨在维护正常的售票秩序,提高用户满意度.并以Z66为例进行方法应用分析,验证了本方法的有效性.     

基于Logsum 差异和嵌套Logit 模型的 交通出行者效益测算研究

交通政策,项目投资及管理措施等会对交通系统出行者的行为方式产生影响, 进而影响系统出行者的经济效益,因此需要科学估计和合理测算.从交通经济领域效益估 算的常用方法着手,在对传统基于rule-of-half 的效益测算方法进行分析的基础上,重点 探讨基于Logsum差异的效益测算方法.构建出行决策的3 层嵌套Logit 模型,从目的地- 方式-路径选择角度建立出行者的效用表达式及方式选择模型,提出基于嵌套Logit 模 型和Logsum差异的效益测算方法;结合案例和情景分析验证方法的应用,并与传统测算 方法进行比较.结果表明,当自变量相对基准情况有较大变化时,rule-of-half 方法和 Logsum 方法的计算结果会有较大差异,在需求非线性变化情况下,基于Logsum 差异的 测算结果更为合理.     

配电系统用户端无功补偿器的开发研究

介绍了一种配电系统用户端无功补偿器的技术方案，对其工作条件及运行性能进行了研究，并给出了研究结果。     

A route-based solution algorithm for dynamic user equilibrium assignments

The aim of this study is to establish a method to calculate good quality user equilibrium assignments under time varying conditions. For this purpose, it introduces a dynamic network loading method that can maintain correct flow propagation as well as flow conservation, and it shows a novel route-based solution algorithm. This novel algorithm turns out to be convenient and logically plausible compared to the conventional [Frank, M., Wolfe, P., 1956. An algorithm for quadratic programming. Naval Research Logistics Quarterly 3, 95–110] algorithm, because the former does not require evaluation of an objective function and it finds solutions maintaining correct flow propagation in the time-varying network conditions. The application of novel dynamic network loading method and solution algorithm to test networks shows that we can find high quality dynamic user equilibrium assignment. This is illustrated in an example network using the deterministic queuing model for a link performance function and associating costs and flows in a predictive way in discrete time.     

Computing dynamic user equilibria for large-scale transportation networks

In this paper, we present an approach for determining dynamic user equilibria. The method is suitable for disaggregated microscopic and mesoscopic simulation-based models. It is a modification of the convex-simplex method, which disposes with the line search step, and controls the subset of travelers to be re-routed at each step while updating the link travel times after each assignment. To guarantee finite termination, a suitable stopping criterion is adopted. The proposed method is implemented within TRANSIMS, the Transportation Analysis and Simulation System, as a two-stage process that employs a combined use of link performance functions and a microsimulator in order to design a framework suitable for application to real transportation systems. To demonstrate this capability, we apply the developed methodology to a large-scale network, Bignet, which is part of the transportation city network of Portland, Oregon; and a medium-scale network, Blacksburg, Virginia; and provide some comparative analyses. Our results exhibit that an improved distribution of travelers is obtained while consuming less than 17–33% of the effort required by the current version of TRANSIMS.     

一种联合式自适应多用户检测算法

自适应多用户检测器没有充分利用多用户信号特点，为此，提出联合式自适应算法，以接收信号作为参考信号，而自适应滤波器的输入信号变为各用户扩频序列的采样值，分析和仿真结果表明。该类自适应多用户检测器具有更高的收敛速度和抗远近效应的能力。     

基于出行时间预算的SUE交通分配

基于均匀分布的路段容量,分析了降级路网中路段和路径出行时间的随机变动,假定出行者根据以往的出行经验获取路径出行时间的可变性,并以出行时间预算的形式将这种可变性纳入到其路径选择过程中,进而定义路径出行时间预算为路径出行时间均值与出行时间安全边际之和.在此基础上,采用变分不等式技术构建了基于出行时间预算的多用户类型弹性需求随机用户均衡交通分配模型,并证明了模型解的等价性.     

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本文考虑了在市场竞争条件下的不同客运方式之间的客流分配，以及在同一种方式中不同服务方式之间的客流分配问题，建立了随机用户平衡配流模型。在此基础上，同时考虑了乘客与客运部门两方面的利益，构造了一个三层规划模型以得到在市场竞争条件下制定客运价格的优化策略模型。既保证乘客的出行费用最优，又能使总的客运需求在不同的运输方式之间合理的分配。     

Multiclass fuzzy user equilibrium with endogenous membership functions and risk‐taking behaviors

Over the last decades, several approaches have been proposed in the literature to incorporate users' perceptions of travel costs, their bounded rationality, and risk‐taking behaviors into network equilibrium modeling for traffic assignment problem. While theoretically advanced, these models often suffer from high complexity and computational cost and often involve parameters that are difficult to estimate. This study proposes an alternative approach where users' imprecise perceptions of travel times are endogenously constructed as fuzzy sets based on the probability distributions of random link travel times. Two decision rules are proposed accordingly to account for users' heterogeneous risk‐taking behaviors, that is, optimistic and pessimistic rules. The proposed approach, namely, the multiclass fuzzy user equilibrium, can be formulated as a link‐based variational inequality model. The model can be solved efficiently, and parameters involved can be either easily estimated or treated as factors for calibration against observed traffic flow data. Numerical examples show that the proposed model can be solved efficiently even for a large‐scale network of Mashhad, Iran, with 2538 links and 7157 origin–destination pairs. The example also illustrates the calibration capability of the proposed model, highlighting that the model is able to produce much more accurate flow estimates compared with the Wardropian user equilibrium model. Copyright © 2016 John Wiley & Sons, Ltd.     

Modeling and solving discrete network design problem with stochastic user equilibrium

In this paper, we address the discrete network design problem, which determines the addition of new roads to existing transportation network to optimize the transportation system performance. Road users are assumed to follow the traffic assignment principle of stochastic user equilibrium. A mixed‐integer nonlinear nonconvex problem is developed to model this discrete network design problem with stochastic user equilibrium. The original problem is relaxed into a convex mixed‐integer nonlinear program, whose solution provides a lower bound of the original problem. The relaxed problem is then embedded into two proposed global optimization solution algorithms to obtain the global optimal solution of the problem. Copyright © 2016 John Wiley & Sons, Ltd.