直线电机轨道交通线路设计参数研究

介绍直线电机轨道交通线路设计参数的计算依据,并建立车线耦合动力学模型进行计算仿真予以验证,给出广州市轨道交通4号线工程线路设计参数的建议值。     

Rescheduling through stop-skipping in dense railway systems

Based on the analysis of the railway system in the Paris region in France, this paper presents a rescheduling problem in which stops on train lines can be skipped and services are retimed to recover when limited disturbances occur. Indeed, in such mass transit systems, minor disturbances tend to propagate and generate larger delays through the shared use of resources, if no action is quickly taken. An integrated Integer Linear Programming model is presented whose objective function minimizes both the recovery time and the waiting time of passengers. Additional criteria related to the weighted number of train stops that are skipped are included in the objective function. Rolling-stock constraints are also taken into account to propose a feasible plan. Computational experiments on real data are conducted to show the impact of rescheduling decisions depending on key parameters such as the duration of the disturbances and the minimal turning time between trains. The trade-off between the different criteria in the objective function is also illustrated and discussed.     

高等级公路线形安全性的模糊评价法

采用层次分析法确定线形指标权重的分配,用改进的德尔菲法建立了评价矩阵,结合模糊评判法,计算出高速公路线形安全性的状况,此法对选择公路线形指标具有重要意义.     

On Diophantine Equation X（ X ＋ 1 ） （ X ＋ 2） （ X ＋ 3） = 14Y（Y＋1）（Y＋2）（Y＋3）

The Diophantine equation X(X+1)(X+2)(X+3)=14Y(Y+1)(Y+2)(Y+3) still remains open.Using recurrence sequence,Maple software,Pell equation and quadraric residue,this paper proved it has only two positive integer solutions,i.e.,(X,Y)=(5,2),(7,3).     

基于物料分类的供应商选择及采购策略研究

针对当今供应商评价方法存在的不足,由企业采购物料的分类入手,对供应商进行相应的分类,为各类供应商构建不同的选择指标体系,再利用层次分析法来进行选优,定量地得到供应商相对于评价指标的综合值与综合排序,最后利用线性规划给出了物料采购任务在各个供应商之间的分配模型。     

预应力混凝土连续梁桥线形控制影响因素研究

文章结合沪宁城际高速铁路某预应力连续梁桥工程实例,采用有限元计算软件,分析了混凝土弹性模量、混凝土容重、预应力、温度、混凝土收缩徐变等因素对该桥主梁线形控制的影响,并提出了相应的控制措施。     

大跨度连续箱梁桥悬臂施工线形监控方法

文章基于佛山市桂澜大桥连续箱梁悬臂施工实例,阐述了大桥施工线形监控的内容及方法,并利用有限元模型对该桥各施工阶段的累计挠度和预拱度值等线形指标进行了计算分析。     

DCT直线型换挡动力学仿真（续1）

为了使汽车冲击度和离合器滑摩功能够满足换挡品质的要求,文章对装有双离合器自动变速器（DCT）的汽车进行了动力学仿真分析,建立其变速器动力传动系统模型。并针对变速器直线型换挡过程中冲击度和滑摩功难以同时达到最优的问题,采用遗传算法对离合器油压值进行优化控制,获得油压-时间的最优控制曲线,将优化后的控制曲线代入仿真模型,结果表明,冲击度和滑摩功均达到较为理想的状态。     

Designing optimal autonomous vehicle sharing and reservation systems: A linear programming approach

Autonomous vehicle (AV) technology holds great promise for improving the efficiency of traditional vehicle sharing systems. In this paper, we investigate a new vehicle sharing system using AVs, referred to as autonomous vehicle sharing and reservation (AVSR). In such a system, travelers can request AV trips ahead of time and the AVSR system operator will optimally arrange AV pickup and delivery schedules and AV trip chains based on these requests. A linear programming model is proposed to efficiently solve for optimal solutions for AV trip chains and required fleet size through constructed AVSR networks. Case studies show that AVSR can significantly increase vehicle use rate (VUR) and consequentially reduce vehicle ownership significantly. In the meantime, it is found that the actual vehicle miles traveled (VMT) in AVSR systems is not significantly more than that of conventional taxis, despite inevitable empty hauls for vehicle relocation in AVSR systems. The results imply huge potential benefits from AVSR systems on improving mobility and sustainability of our current transportation systems.     

基于先验信息的自适应核函数设计

针对多分量线性调频信号，提出一种新的自适应核函数，并给出了有效的核参数估计方法。相对于自适应高斯核函数而言，该核函数既能获得更好的交叉项抑制效果，又避免了较大的信号能量损失，因而是一种更好的核函数。计算机仿真结果验证了其有效性。