关于铁路货车提速对车辆的影响分析及检修意见

随着我国经济科技的不断发展,我国铁路事业也上升到新的台阶。新形势和货车的提速对车辆提出了更高的要求。本文从货车提速基本现状出发,分析新速度下的货车运载面对的问题,扎根基础,简述分析铁路货车提速对车辆的影响并提出可行性检修意见。本文通过查阅文献和相关实例,提出积极应对高速环境下车辆的安全隐患,因地制宜选择先进的检修技术,规范化管理检修工作,避免不良事件发生,从而加速行业良性建设,是保障铁路货车的安全工作重要组成部分。

A model for end-of-life vehicles management based on green manufacturing

Like any industrial product, the vehicles also do have end of their service lives and ultimately result in end-of-life vehicle (ELV) at a certain stage of the vehicle life. The concern of this paper is to make a general review on ELV management process and present a model for ELV management on the basis of green manufacturing so as to reduce the environmental impact and minimize the resources loss due to the ELVs. The various phases of vehicle life cycle starting from design, manufacturing and utilization, occurrence of ELV and then the storage, depollution, dismantling and finally the shredding and post shredder material processing phases of ELV for the resources recovery, all of these phases need to be considered to give totality to the model, which makes end-of-life vehicles management more benign for environment, and more efficient for the usage of resources.

Connectivity of sparse vehicular ad hoc networks with channel randomness

In this paper, we investigate the connectivity of vehicular ad hoc networks in free-flow traffic situation with channel randonmess. In order to illustrate the realistic environment, we consider that vehicles are distributed in free-flow highway according to a Poisson point process, and signal propagation between connected vehicles is subjected to log-normal shadowing effects. We obtain the distribution of the space headway between successive vehicles and the distribution of signal coverage, which allows us to use the equivalent M/G/z~ queue theory to model the connectivity of VANETs in the form of average broadcast percolation distance and average number of connected nodes. Then, extensive simulation studies are conducted to evaluate the obtained results. The analytical model presented here is able to describe the impact of various system parameters, including traffic parameters and signal propagation parameters on the con- nectivity. We use our analytical results, along with the common signal propagation data, to understand impact of channel randomness on the connectivity of VANETs.

基于边缘智能的城市下穿隧道车辆行车安全预测

针对传统预测方法对城市下穿隧道进行行车安全预测时,没有全面分析车辆行车安全的影响因素,存在行车安全预测精度低和预测结果不稳定的问题,本文提出了基于边缘智能的城市下穿隧道车辆行车安全预测方法。首先,构建一个边缘智能深度学习模型,对行车数据进行获取和处理,分析行车安全的影响因素。然后,根据分析结果,对城市隧道不同交通流状态下行车时的交通冲突进行了预测。最后,通过仿真对比了该方法与两种传统机器学习算法的预测性能。结果表明,本文方法能够预测交通事故发生的风险性,对城市下穿隧道行车安全预测的精度在90%以上,较传统方法具有更高的准确度。

不同交通流状态下桥梁气动导数的风洞试验研究

为了考虑实际运营车辆对桥梁气动导数的影响,根据车辆密度模拟了三种交通流状态,基于强迫振动装置,分别对每个交通流和无车状态下的桥梁气动导数进行风洞试验研究,讨论了不同攻角下不同车流的车辆对桥梁气动导数的影响,探究了车辆对气动导数影响的百分比以及气动导数变化量的变化规律。研究结果表明:不同攻角下不同车流的车辆均对直接导数A*2、H*4和交叉导数A*4、H*2影响显著,A*2、A*3变化量随着折减风速有一定的变化规律。虽然不同攻角下不同车流的车辆对气动导数的影响程度及影响规律不同,并且车流的繁忙程度对大多数气动导数的影响规律不明显,但是车辆对桥梁气动导数的影响不容忽略。