地铁轨道安装方面的设计优化

以郑州地铁1号线一期工程的轨道配合施工为例,从钢轨数量计算、铺轨基地选择、轨道专业与人防门专业接口、立柱式检查坑道床等方面分析轨道施工过程中出现的问题,指出地铁轨道专业在设计阶段存在的不足,并提出地铁轨道优化设计的建议。     

大准铁路TDCS系统升级方案研究

结合大准铁路复线改造工程的进展,对列车调度指挥系统由TDCS升级到CTC的必要性、工程实施模式、具体实施方案、后续的维护管理等进行了深入细致地研究,提出了实现运输生产秩序不受影响,工程实施平稳、无缝过渡的具体实施方案。     

盾构施工筹划原则及影响因素分析

以北京地铁4号线11合同段(灵境胡同-新街口)四站三区间的盾构施工筹划为例,重点分析影响盾构施工筹划的因素;以方案比较的方法,介绍了确定三区间总体筹划方案的详细过程.     

直线电机列车-高架桥系统动力相互作用分析

采用模态综合技术,建立直线电机轨道交通系统的车桥动力相互作用分析模型,对直线感应电机轨道交通系统的电磁力的产生及其对列车、高架桥梁的动力作用进行理论分析和研究,指出这是进一步研究城铁高架桥梁的动力响应以及直线电机列车在桥上的运行安全问题的一种可能途径。     

针对自适应巡航的驾驶人风格辨识

车辆进入自适应巡航工况下行驶时,不同风格的驾驶人会对自适应巡航控制系统(Adaptive Cruise Control,ACC)有不同的需求。文章首先通过对不同驾驶人在9种跟随试验下获取的实验数据分析,选取表征驾驶人风格的驾驶特征参数;其次对所有驾驶人驾驶特征参数利用K-mean算法聚类分析,将驾驶人三类,并利用BP神经网络建立辨识模型对驾驶人风格进行辨识。结果表明;文章提出的方法可以较高的准确率对驾驶人风格进行分类,提高自适应巡航系统适应驾驶人的能力。     

基于深度学习的智能车辆视觉里程计技术发展综述

针对基于模型的视觉里程计在光照条件恶劣的情况下存在鲁棒性差、回环检测准确率低、动态场景中精度不够、无法对场景进行语义理解等问题,利用深度学习可以弥补其不足。首先,简略介绍了基于模型的里程计的研究现状,然后对比了常用的智能车数据集,将基于深度学习的视觉里程计分为有监督学习、无监督学习和模型法与深度学习结合3种,从网络结构、输入和输出特征、鲁棒性等方面进行分析,最后,讨论了基于深度学习的智能车辆视觉里程计研究热点,从视觉里程计在动态场景的鲁棒性优化、多传感器融合、场景语义分割3个方面对智能车辆视觉里程计技术的发展趋势进行了展望。     

外加电流补偿方法静电场抑制效果研究

在深入研究外加电流补偿方法基础上,分析了补偿阳极位置、补偿阳极输出电流对静电场抑制效果的影响,结合船模试验验证了分析结论.试验结果表明,补偿阳极位置应尽量靠近螺旋桨,才能保证补偿电流对静电场的抑制效果;补偿阳极输出电流增加到一定程度时,静电场抑制效果最佳.     

利用CIVIL 3D进行海港工程疏浚设计方法研究

本文在南方某海港工程港池航道工程设计中引入BIM正向设计,利用CIVIL3D建立了地形曲面和地质曲面模型,建立采样线,对地形曲面、设计曲面、地质曲面进行采样;用断面法进行疏浚工程量计算,用程序自带网格施工图及其他软件等多种方法进行校核以验证计算准确性;通过材质定义,计算不同土类疏浚量并在断面图中表示;在设计完成后,按其自带的出图功能生成断面图组,批量对其表达形式、格式、显示内容进行统一调整,提高设计工作效率及准确性。可为类似工程引进BIM进行正向设计提供参考。     

Micro-Grinding Performance of Hard-Brittle Chip Materials in Precision Micro-Grinding Microgroove

The micro-structure on hard-brittle chip materials (HBCMs) surface can produce predominant functions and features. The micro-grinding with diamond wheel micro-tip is an efficient method to machine microstructure on HBCMs. However, different HBCMs and crystal orientation may have a significant influence on the micro-grinding performance. In this paper, the micro-grinding performance along different crystal orientation of HBCMs is investigated. First, a dressed 600^# diamond grinding wheel is used to micro-grind micro-structure on HBCMs. Then, the experiment of micro-grinding force test is completed. Finally, the quality of microgroove, the grinding ratio and the micro-grinding force are investigated and they are related to the crystal orientation of HBCMs. It is shown that the stronger resistance to the micro-crack propagation has the best quality of microgroove and the smallest grinding ratio. Moreover, the hardest single-crystal SiC has the best machinability and the micro-grinding force is 38.9%, 10.8% and 46.8% less than the one of sapphire, single-crystal Si and quartz glass, respectively. The direction to micro-grind easily is the crystal orientation 〈10\(\overline 1 \)0〉 for single-crystal SiC and sapphire. In addition, the micro-grinding force increases with the increase of the micro-grinding depth and feed rate and decreases with the increase of the grinding wheel speed.     

Lattice-based group signature with verifier-local revocation

Among several post quantum primitives proposed in the past few decades, lattice-based cryptography is considered as the most promising one, due to its underlying rich combinatorial structure, and the worst-case to average-case reductions. The first lattice-based group signature scheme with verifier-local revocation(VLR) is treated as the first quantum-resistant scheme supported member revocation, and was put forward by Langlois et al. This VLR group signature(VLR-GS) has group public key size of O(nm log N log q), and a signature size of O(tm log N log q log β). Nguyen et al. constructed a simple efficient group signature from lattice, with significant advantages in bit-size of both the group public key and the signature. Based on their work, we present a VLR-GS scheme with group public key size of O(nm log q) and signature size of O(tm log q). Our group signature has notable advantages: support of membership revocation, and short in both the public key size and the signature size.