车用儿童约束装置建模与仿真分析

文章使用多刚体系统动力学软件MADYMO对某类型CRS进行仿真分析,并通过台车试验验证所建模型的正确性,利用该模型对CRS的设计参数进行灵敏度分析,找出影响CRS安全性能的2个敏感参数,在材料特性和结构尺寸允许的范围内进行了改进,改进后模型的安全性能有了一定提高。为该类型CRS的改进提供参考,同时也为新型CRS的研制提供理论依据。     

广州市城市公共停车场发展政策研究

为从交通政策层面上积极推进广州市城市公共停车场的建设,引导其健康、有序发展,在分析了广州市现行停车政策现状及问题的基础上,从法律法规建设、相关鼓励政策、停车收费政策、投资模式等方面介绍了国内外城市公共停车场发展政策。最后,提出适合广州市公共停车场发展的政策建议,并强调停车发展政策只有由单纯以需求为导向的适应性政策转向有利于停车需求管理的引导性政策发展,才能适应城市交通可持续发展的要求。     

满足国Ⅲ排放的摩托车尾气净化催化剂

摩托车尾气净化催化剂能有效地将摩托车尾气中的HC、CO和NOx成分转化成CO2、H2O和N2,从而消除污染[1].     

A novel numerical method for the hydrodynamic analysis of floating bodies over a sloping bottom

Journal of Marine Science and Technology - A novel numerical method combining Eigenfunction matching method (EMM) and 3D Rankine source method is developed to investigate wave-body interaction over...     

融合导向的杭州公共交通机制政策研究

为促进城市公共交通内部各方式的衔接与融合,以杭州为例,从机制层面对其"四位一体"大公共交通系统内部的融合发展策略进行探讨.分析杭州现状公共交通系统在组织机制、运营管理等方面面临的问题与挑战,并借鉴新加坡、伦敦公共交通管理先进经验,提出通过建立部门协作和反馈机制来构建强有力的组织保障;建立"四位一体"公共交通系统内部的换乘优惠,优化各方式间的比价关系,推广多元融合票制,提升公共交通系统吸引力;针对各类线路差异化地制定补贴指标和融合导向的公交服务考核指标体系,提升公共交通系统的服务品质.     

Research on anti-counterfeiting quick response 2D barcode techniques based on digital watermark

In order to increase the watermarking capacity and improve the anti-counterfeiting performance of quick response (QR) two-dimensional (2D) barcode based on digital watermarking technique, this paper proposes a kind of graying algorithm for binary image to make transform domain watermarking methods possible. Based on the graying algorithm, the quantization-based watermarking scheme in discrete wavelet transform (DWT) domain is then designed. The experiments show that the proposed watermarking scheme for QR 2D barcode greatly improves anti-counterfeiting performance without loss of any barcode information.     

车道偏离预警模糊控制算法研究

车道偏离预警系统多采用固定的横向偏移量或者预计跨越车道时间作为预警的阈值,在实际应用中不能很好的适应每个驾驶员个体。提出了一种车道偏离预警模型,该模型是对轮胎距车道线距离和预计跨越车道时间这两个车辆状态信息建立模糊控制规则,通过Simulink模糊控制模块进行仿真,实现对车道偏离危险等级的确定。驾驶员只需选择一个适合自己的车道偏离预警风险等级即可,此车道偏离预警模型能够减少报警中虚报和漏报。     

基于Abaqus的汽车车门瞬态应力分析

为评估汽车车门在关闭过程中的强度性能,基于Abaqus对某汽车车门关闭的瞬态冲击应力进行了研究.提出了一种新型的锁机构建模方法,合理定义了系统的阻尼系数,从而获取了精确的应力结果.分析表明,瞬态应力分析可准确预测车门关闭过程中各时刻的应力,从而找到薄弱区域,为车门的强度耐久设计提供依据.     

Multi-resolution modeling and simulation for urban rail transit network planningEI北大核心

Research purposes: Simulation technology plays an important role in the urban rail transit network planning and analysis. With the enlargement of the urban rail network scale, the complexity and difficulty in the development of simulation system for urban rail transit network planning increase. To develop the simulation system with high efficiency, an approach to multi-resolution modeling and simulation of urban rail transit system is presented. Research conclusions: (1) An approach to build a multi-resolution simulation system of urban rail transit is presented, by building and integrating transit network architecture models and passenger models in different resolutions. (2) Ahierarchical model of rail transit network topology is built to resolve the problem of spatial consistency in multi-resolution modeling. (3) A polymerization based station simulation model is built to resolve the problem of state consistency. (4) To meet the needs of extensibility and flexibility of the simulation system, an agent-based integration method is applied to develop the simulation system of urbanrail transit network. (5) Arealized example on the application of the simulation model is introduced, which is used to analyze and evaluate a transit network planning.     

预应力混凝土箱梁施工

通过对梨树园蒲石河大桥箱梁的预制施工,全面总结了从箱梁立模、混凝土浇注到预应力钢束张拉、灌浆、封锚全过程的施工工艺,提供了相应的施工方法、混凝土配合比、振捣时间和预应力张拉等各种技术数据。