带有压力补偿模块的容积式阀位指示器

文章分析了造成容积式阀位指示器在船舶液压阀门遥控系统中应用产生误差的因素,介绍了一种新颖的带有压力补偿模块的容积式阀位指示器.这种阀位指示器可在系统工作压力高、控制管路长的工况下有效提高阀位指示器的测量精度,可广泛应用于大型船舶液压阀门遥控系统.     

欧标EN1992-1-1:2004与中国规范JTS 151—2011的异同

众多的海外设计项目要求设计者了解和掌握欧美的设计标准,通过项目设计实践,总结了欧洲设计标准体系之一的混凝土结构设计规范：EN1992-1-1:2004与我国标准JTS 151—2011 在设计原则与方法、材料特性、荷载系数、荷载组合、承载力计算等方面的异同点,供同行参考。     

基于深度学习的驾驶员状态识别

提出了基于驾驶员脸部及周围信息的驾驶员状态检测方法。文章通过实车摄像头采集了驾驶员驾驶状态视频数据,利用Dlib和OpenCV库对采集的驾驶员图像进行脸部检测,基于驾驶员脸部数据建立了深度学习数据集,然后基于该数据集设计了一种卷积神经网络模型FaceNet,利用PyTorch深度学习框架在数据集上对模型进行训练,最终得到了有较高准确率的驾驶员状态检测模型,其可识别抽烟、睡觉、左手打电话和右手打电话四种驾驶员状态。     

Contents Index Volume 35 and 36

Active safety systems would benefit from tyre force and friction potential information. Different sensor concepts, including, among others, the EU–funded Apollo–project developed tyre sensor based on optical position detection, are being studied. The sensor can measure tyre carcass deflections with respect to the rim. The carcass deflections can be used to calculate tyre forces and they may be exploited in the estimation of friction potential. The waveforms of the sensor signal are illustrated. The vertical and lateral force estimations are presented with unavoidable compensation parts. The tyre sensor measurements were compared to the measurement–vehicle results and good correlations achieved. Continuing activities are concerned with the estimation of friction potential and the detection of aquaplaning.     

唐前咏书文学简论

唐前咏书文学以赋为主,诗、散文少许。凡标明＂体＂、＂势＂、＂状＂的咏书文都是赋,＂赞＂和＂铭＂应为诗。程式化倾向,铺陈描写,多用比喻,侧重表现书法的动态美、力感和生命感,语言华丽富赡,是咏书文学的共同特点。唐前咏书文学作为一种新的题材,开启了唐代以后咏书文学的先河,在文学发展史上具有相当重要的地位。     

考虑沥青路面材料参数空间差异性的解析计算及影响分析

复杂服役环境下沥青路面的材料参数存在明显的空间差异性，具体表现为沿深度的模量梯度分布与非连续层间接触以及横观各向同性，实现其解析计算对现有的沥青路面力学响应分析及结构设计方法具有重要的参考价值。为此，从弹性力学基本方程出发，基于状态空间法，推导了具有指数模量梯度的横观各向同性弹性层状体系通解；在此基础上，基于波传递方法，将状态向量转换为波向量，并结合边界条件和层间条件，建立了考虑沥青路面材料参数差异性的多层路面结构解析解；然后借助MATLAB平台编制了数值计算程序，采用文献对比、BISAR程序以及有限元软件ABAQUS验证了该解析解的精度与效率；最后结合典型数值算例，阐述了该解析解在沥青Top-Down开裂和传统路面疲劳损伤分析中的应用。理论推导和数值计算结果表明：该解析解摆脱了弹性力学问题求解对应力函数的依赖性，并且借助波传播方法，避免了求解中正指数过大对求解精度的影响，并使得边界条件和不同层间接触关系的描述更加便捷；沥青路面材料参数的空间差异性不可忽视，沥青面层连续模量梯度会造成更大的路表拉应力和最大剪应力，进而加剧沥青路面的Top-Down开裂；而横观各向同性和层间接触状态间存在耦合效应，从而会加剧沥青路面的疲劳损伤。     

桥面物理除冰雪加热功率与环境因素关系分析

为解决化学融雪剂腐蚀桥梁结构和污染环境的问题，提出桥面敷设加热电缆方式除冰雪技术方案，以30m预应力混凝土T梁桥、沥青混凝土桥面为分析对象，进行了瞬态热分析和稳态热分析，系统研究了在桥面加热升温和稳态融雪节段加热功率与环境温度和环境风速的关系。经分析可知桥面加热过程可分为滞后、升温和稳态三个阶段，得出了一些有意义的结论，可为桥面敷设加热电缆除冰雪设计提供理论参考。     

基于卡尔曼滤波算法的电机转速精确估计

从无刷直流电机入手建立数学模型，利用卡尔曼Kalman（EKF）滤波原理算法，对无刷直流电机的转速进行精确估计，然后在Matlab环境下仿真，验证卡尔曼滤波算法对电机转速估计的精确性。     

Women’s mode and trip structure choices in daily activity-travel: a developing country perspective

ABSTRACT

In this paper, we analyze the travel patterns of Iranian women, where typical patriarchal views and specific social and cultural norms may differ from the patterns of those in western societies. In addition to inherent psycho-physical gender differences, women in Iran can face special constraints forcing them not to be involved in all activity-travel patterns that people in developed countries usually undertake. We pay special attention to the role of marital and employment status on women’s activity-travel patterns. To this end, we develop a joint mode and daily activity pattern (DAP) discrete choice model, which is a two-level mixed nested Logit. The upper nest of the proposed model embodies women’s DAP choices, and the lower nest belongs to the mode choices. In this paper, we try to show how different factors in a patriarchal Muslim society like Iran affect or restrict women’s type and structure of activity-travel patterns.