无人机测控信道衰落特性及其抑制方式

分析了无人机测控信道模型以及由小规模衰落带来的非频率选择性衰落、频率选择性 衰落与时间选择性衰落的产生机理及特性,并针对这3种衰落进行了抑制方法分析,指出O FDM、交织与编码以及空间分集是无人机测控中值得重点研究的抗衰落技术。     

增程式电动汽车产业浅析

新能源汽车是未来汽车产业转型发展的重要方向。我国新能源汽车前期发展取得了突出的成绩,产销量位居世界首位。但目前产业发展正面临新形势,未来一段时期内将由“政策驱动”转向“政策+市场双驱动”。到2021年购置补贴完全退出后的后补贴时代,如何保障新能源汽车产业的健康、可持续发展,值得人们共同思考,开发什么类型的产品才能更好地满足消费者的需求,值得行业企业考虑。     

一种基于微波雷达回波信号的车型分类方法

车辆类型识别方法是智能交通系统的关键技术之一。利用深度学习的高维特征泛化学习能力,将改进的LeNet-5卷积神经网络用于基于交通微波雷达的大小车型分类识别。首先,以雷达触发前的N帧信号为基础,对雷达的回波信号进行分析并构建数据集;然后,分析LeNet-5卷积神经网络的特点;最后提出一种改进的LeNet-5卷积神经网络。实验结果表明,与传统的支持向量机方法相比,所提方法能够智能学习大小车的雷达时频信号特征,大小车型识别准确率达到97%以上,可为交通场景下的车型识别研究提供新的技术途径。     

时变路网无能力约束车辆路径优化

讨论了一类时变路网下的无能力约束车辆配送路径优化问题,建立了基于时变路网的以配送总耗时最短为优化目标的无能力约束车辆配送路径优化模型。提出了基于实时Dijkstra算法的模型求解方法。数值算例表明考虑路网时变特性得到的优化配送方案将更加符合配送实际。     

针对车辆AEB系统失效和误作用场景的研究

本文基于预期功能安全,采用功能分解方法,总结出部分车辆自动紧急制动(AEB)系统失效和误作用场景,并从中选取典型场景作为测试场景,开展不同车型的实车道路试验,总结出AEB系统的缺陷与隐患分类.希望此类研究能为AEB系统失效和误作用测试标准的制定提供参考.     

多轴轮式车辆操纵稳定性试验研究

汽车操纵稳定性试验和评价方法不能完全适用于多轴车辆,制定和完善多轴车辆的操纵稳定性试验方法具有现实意义。针对某前四轮转向四轴车辆,制定了操纵稳定性试验方案,进行了定半径稳态回转试验、蛇行试验和转向盘转角脉冲输入试验,对该车稳态与瞬态转向特性进行了评价,为多轴车辆操纵稳定性试验与评价的科学化与规范化奠定了基础。     

E-Shopping Patterns of Chinese and US Millennials

A conceptually based taxonomy of 22 distinct forms of e-shopping vehicles is proposed. A modification of the UTAUT and UTAUT2 models is introduced to explain how vehicles are interrelated in regard to consumer reliance upon them for their e-purchasing. A survey of over 1,000 millennial university students, 697 Chinese and 306 US, revealed strong support in both samples for the hypothesized six dimensional pattern underlying consumer vehicular reliance. Further, differences between Chinese and US samples lay not in the nature of the dimensions, but rather in the strength of reliance upon each dimension. Thus, the study demonstrates the utility of the concept/measure of shopper vehicular reliance, VPR (Vehicle Purchasing Reliance) for both practitioners and scientists. In cross-national comparisons, observed differences between samples in strength of reliance supported four of five hypotheses predicated on previously established national distinctions a) in trust and b) in the cultural value of individualism-collectivism.     

Assessing greenhouse gas emissions from electric vehicle operation in Australia using temporal vehicle charging and electricity emission characteristics

ABSTRACT

Significant interest exists in the potential for electric vehicles (EVs) to be a source of greenhouse gas (GHG) abatement. In order to establish the extent to which EVs will deliver abatement, however, a realistic understanding of the electricity and transport sector GHG emissions impacts arising from different approaches to integrating EVs into the power system is required. A key issue in this regard is the extent to which GHG emissions are a function of where and when EV charging will be enabled (or disabled) by the provision of recharging infrastructure and implementation of charging management strategies by the electricity industry. This article presents an investigation of the GHG emissions arising from electricity and gasoline consumption by plug-in hybrid EVs under a range of standard EV-power system integration scenarios. An assessment framework is presented, and GHG emissions from EV use are assessed for the New South Wales (NSW) and South Australian (SA) pools of the Australian National Electricity Market (NEM) using retrospective electricity system generation data for 2011. Results highlight that there is a range of possible outcomes depending on the integration scenario and emissions accounting approach used. This range illustrates value of a temporally explicit assessment approach in capturing the temporal alignment of electricity sector emission intensity and EV charging. Results also show the importance of a clean electricity generation mix in order for EVs to provide a GHG abatement benefit beyond what would be achieved by a hybrid (but non-plug-in) vehicle. The extent to which overnight charging in NSW is observed to produce higher emissions relative to unmanaged charging also illustrates a possible trade-off between GHG emissions and benefits for electricity industry from EV charging at times of low demand.     

某物流配送中心运输车辆噪声对居民的影响

一些企业在生产过程中排放的噪声级较高,干扰了周围居民的正常生活,导致居民对噪声污染的投诉越来越多。为了明确某企业噪声对周围居民区的影响范围和程度,通过测定某物流配送中心运输车辆及其周边敏感点的噪声值,采用导则推荐的模型,预测了运输车辆对敏感点的等效声级(Leq)和最大A声级(Lmax),从实测和预测2个途径,明确该物流配送中心运输车辆噪声对周围敏感点的影响,分析各敏感点噪声的超标情况。将等效声级预测结果与实测结果相比较,预测结果稍大于实测结果,两者相差1~2dB(A),表明预测结果可信。根据敏感点噪声超标情况,提出了运输车辆噪声控制对策,以减少该物流配送中心车辆噪声对居民的影响。     

西方经验背景下的俄罗斯报废汽车回收利用

俄罗斯是以汽车作为主要交通工具的国家之一。但长期以来,俄罗斯的老旧汽车回收始终处于粗放的自发状态。造成了环境污染和资源浪费。借鉴学习他国经验,建立自己的报废汽车回收利用体系,成为俄罗斯政府和社会的迫切任务。近年来,俄罗斯在这一领域取得了显著进展。