基于加权云模型的全电子联锁系统运营安全风险评估

结合现场实际情况,在系统层面对于全电子计算机联锁系统进行更加客观准确的运营安全评估,综合考虑系统的风险严重度及风险可能性,提出一种基于最优组合权重计算法的云模型安全评估方法。首先从人员、设备、环境、管理、维修5个方面建立安全风险评估体系,在专家评估的基础上运用最优组合权重法计算体系中的底层指标权重,再将权重代入评估云模型的计算中,分别得到系统的风险可能性和风险严重度评估值,综合得出系统的运营安全风险容忍等级。将该方法引入全电子联锁系统的运营安全评估中,通过对实际数据的计算,证实该方法能够克服以往评估方法的主观性和片面性,使得到的结果更加准确和直观,实现真正意义上的“综合”评估。     

道岔融雪控制系统典型问题分析与优化设计

随着各型号道岔融雪系统的推广应用,一些普遍存在的典型问题也逐渐暴露出来。在分析并总结问题的基础上,基于C#面向对象技术、单片机技术和CAN总线环网技术,从人机交互设计、生产效率与兼容性、系统性能、控制可靠性与兼容性四个方面进行了优化设计,研发完成了TYDR-B型道岔融雪系统。实验室仿真与现场应用的结果表明,优化设计方案能够很好地解决这些问题,取得了良好效果。     

Optimal vehicle trajectory planning in the context of cooperative merging on highways

One of the main triggers of traffic congestion on highways is vehicle merging at on-ramps. The development of automated procedures for cooperative vehicle merging is aimed to ensure safety and alleviate congestion problems. In this work, a longitudinal trajectory planning methodology is presented, developed to assist the merging of vehicles on highways; it achieves safe and traffic-efficient merging, while minimizing the engine effort and passenger discomfort through the minimization of acceleration and its first and second derivatives during the merging maneuver. The problem is formulated as a finite-horizon optimal control problem and is solved analytically. This enables the solution to be stored on-board, saving computational time and rendering the methodology suitable for practical applications. The tunable weights, used for taking into account the different optimization criteria, may serve as parameters to match the individual driver’s preferences. The proposed methodology is first developed for a pair of cooperating vehicles, a merging one and its putative leader. Moreover, an alternative solution procedure via a time-variant Linear-Quadratic Regulator approach is also presented. A Model Predictive Control (MPC) scheme is utilized to compensate possible disturbances in the trajectories of the cooperating vehicles, whereby the analytical optimal solution is applied repeatedly in real time, using updated measurements, until the merging procedure is actually finalized. Subsequently, the methodology is generalized for a set of vehicles inside the merging area. Various numerical simulations illustrate the validity and applicability of the method.     

A structured flexible transit system for low demand areas

Public transit structure is traditionally designed to contain fixed bus routes and predetermined bus stations. This paper presents an alternative flexible-route transit system, in which each bus is allowed to travel across a predetermined area to serve passengers, while these bus service areas collectively form a hybrid “grand” structure that resembles hub-and-spoke and grid networks. We analyze the agency and user cost components of this proposed system in idealized square cities and seek the optimum network layout, service area of each bus, and bus headway, to minimize the total system cost. We compare the performance of the proposed transit system with those of comparable systems (e.g., fixed-route transit network and taxi service), and show how each system is advantageous under certain passenger demand levels. It is found out that under low-to-moderate demand levels, the proposed flexible-route system tends to have the lowest system cost.     

Distributive Disturbance and Optimal Policy in Stochastic Control Model

IntroductionThe relationship between the output volatility,taxation and macroeconomic performance has receivedconsiderable attention in recent years[110].The find-ings provide some valuable views on how risk affectstax policy and economic growth.All of th…     

450吨冷镦机夹钳机构凸轮廓线的优化改进设计

通过对冷镦机夹钳机构中的凸轮机构失效原因的分析，提出了改进措施，并建立出凸轮廓线代化设计的数学模型和进行了优化设计计算，为旧机床的维修改造提供了一种有效手段。     

船舶上层建筑振动的最优控制分析

本文讨论了最优控制理论在船舶上层建筑振动控制中的应用。文中将船体和上层建筑简化为相应的船体梁和上层建筑梁模型，并将上层建筑梁的振动响应处理为支承激励下的响应。用模态分析法得到船体梁和上层建筑梁的动力特性（固有频率和固有振型），再用模态（振型）叠加法得到受控前上层建筑顶端的稳态动力响应，接着根据最优控制理论，设定目标函数，求解Riccati方程，得到主动控制力，将其作用在上层建筑梁的顶部，用模态（振型）叠加法得到受控后上层建筑梁顶部的稳态动力响应。以一条50000吨的油船为算例进行数值仿真，受控后上层建筑顶部的稳态振动位移减小了30％，可见最优控制在船舶上层建筑的振动控制中是可行的和有效的。     

双层保温层经济厚度的优化计算

通过对双层保温的总费用分析，并考虑到保温的国家标准和工程实际，建立了双层保温层经济厚度优化设计的数学模型，并采用最优化方法进行了编程求解，得到了每层的最佳经济厚度。导出的模型和编制的软件可帮助设计人员合理地选择保温材料并确定其经济厚度，有助于提高设计效率和设计质量。     

基于方法组合的轨道电路故障诊断模型

为了解决单一方法对25 Hz相敏轨道电路的故障诊断精度偏低等问题,提出基于最优权值的多方法组合故障诊断模型。首先通过模糊综合评判、灰色关联分析和BP(Back propagation)神经网络3种不同的诊断方法,对轨道电路进行初步故障诊断,然后根据各诊断方法的误判率计算出对应的最优权值,最后对各方法的诊断输出进行最优权值加权平均得到综合诊断的输出结果,确定故障类型。诊断结果表明:组合诊断模型有效地提高了轨道电路故障诊断的准确度,并证明了组合诊断模型的诊断准确度随着诊断方法的数量增加而提高。     

Relationships between fares, trip length and market competition

This paper analyses equilibrium fares that arise from Collusion, Cournot, Stackelberg, Bertrand and Sequential Price Competition when two profit maximising transport firms produce symmetrically differentiable services and have identical costs. Special focus is placed on how different equilibrium fares are linked to trip length. Higher operator costs and higher demand from the authorities regarding the quality of transport supply result in steeper relationships (larger rate of change) between all fares and travel distance. Also, a higher degree of substitutability between the services will in most cases make these relationships steeper. The competitive situation has less influence on fares, both absolutely and relatively, the longer routes the operators compete on.