基于特征子序列修正的公交刷卡滞后时间推算

针对一票制公共交通IC卡刷卡系统存在的滞后时间问题,提出基于特征子序列修正的时差匹配推算方法。依托GPS车辆到站信息序列和刷卡聚类序列,分析首末站和中途站站间运行时间分布的差异化特征,分别从两序列中提取大时间差和连续小时间差等特征子序列;利用两种子序列间一对一或一对多的对应关系分别进行初步搜索和二次修正,兼顾匹配过程的效率和精度。将推算流程应用于山西省大同市公共汽车系统,结果显示,抽样车辆的刷卡匹配率均达到99%以上,并且针对不同类型的公共汽车线路具有较强的适应性。     

双幅桁架组合梁空间受力研究

双幅桁架组合梁是通过横向联结系将A,B两个单幅桁架组合梁连接到一起组成新结构,为了了解该组合梁的受力性能、变形能力、破坏机理以及各个杆件的内力分布规律等,设计并制作试件,通过对试验梁A幅静力加载试验,分析其位移、沿截面高度纵向应变、混凝土板顶纵向应变、斜腹杆轴向应变以及横向联结系轴向应变随荷载的发展变化。通过ABAQUS有限元分析软件建立相同试件模型并且后处理,比较试验研究成果,验证模型的合理性。研究表明,施加单幅对称荷载时该组合梁具有良好的承载能力和变形能力;破坏形态为A幅弯曲破坏的同时伴随着受拉腹杆节点的冲剪破坏,B幅仅斜腹杆受轴力且影响较小;剪力滞系数在梁肋处达到峰值,说明梁肋处应力分布最不均匀,系数纵向影响范围只位于加载点附近,变形集中于中间区域;下弦杆除了承受轴向力,弯曲效应对杆件的受力影响较大,不容忽视。     

基于分子动力学的车流运行动态特性及其模型

车辆跟驰行为受前导车和道路环境等的影响,将车辆抽象成相互作用的分子,基于分子动力学构建相互作用势函数,建立基于相互作用势函数的分子跟驰模型.采集试验路段不同点位的交通流样本,从视频中获得所需数据,并对加速度波动特性进行分析.将车辆运行状态分为常态行驶,起动加速和减速停车3种,根据实测交通数据对3种车辆运行状态进行模型参数标定,同时对分子跟驰模型进行稳定性分析验证,结果表明,相对于经典GM模型,分子跟驰模型稳定性更好,对实际交通状态拟合程度更高.     

“三图四表”管理制度在轨交基坑施工中的应用

结合宁波轨交1号线一期工程TJ-Ⅷ标东环南路站工程,参建单位对基坑结构风险进行了静态分析与评估,并对基坑设计方案进行了优化。在基坑开挖过程中,通过"三图四表"管理制度对基坑开挖过程进行动态实时的控制,采取了一系列针对基坑变形的控制措施,顺利完成了该站主体基坑的开挖作业。可供欠固结土地区深基坑的设计和施工参考。     

Users’ perceptions and willingness to pay in interurban toll roads: identifying differences across regions from a nationwide survey in Spain

Users’ acceptability is considered one of the key drivers for the successful implementation of transport policy measures. This is especially crucial in the case of toll roads since they are financed through drivers’ contributions. Previous literature in this field has mainly focused on measuring users’ attitudes towards urban congestion pricing strategies. However limited research has been developed concerning interurban toll roads. Previous research shows that socioeconomic variables are not conclusive to explain users’ perceptions towards tolls. By contrast, other drivers such as regional differences seem to play a more important role, especially when charging conditions within the same nation greatly vary across regions. This paper analyzes regional differences in users’ attitudes within an asymmetrical distribution of the toll road network across regions. Based on a nationwide survey conducted to road users in interurban toll roads in Spain, we develop both a binomial logit and a censored regression (tobit) model to explore drivers’ perceptions and willingness to pay. The research concludes that users from regions with a more extensive tolled network generally show a more negative attitude towards charges, but not necessarily a lower willingness to pay. The paper also points out that an asymmetrical distribution of toll roads across regions may result in negative perceptions among those users perceiving to be unfairly treated when compared to citizens in other regions.     

Automatic outer surface extraction of femoral head in CT images

Computer-aided hip surgery planning and implant design applications require accurate segmentation of femoral head and proximal acetabulum. An accurate outer surface extraction of femoral head using marching cubes algorithm remains challenging due to deformed shapes and extremely narrow inter-bone regions. In this paper, we present an automatic and fast approach for segmentation of femoral head and proximal acetabulum which leads to accurate and compact representation of femoral head using marching cubes algorithm. At first, valley-emphasized images are constructed from original images so that valleys stand out in high relief. Otsu’s multiple thresholding technique is applied to seperate the images into bone and non-bone classes. Region growing method and threedimensional (3D) morphological operations are performed to fill holes in the bone. In the reclassification process, the bone regions are further segmented, and the boundaries of the bone regions are further refined based on Bayes decision rule. Finally, marching cubes algorithm is applied to reconstruct a 3D model and extract the outer surface of femoral head and proximal acetabulum. Experimental results show that this method is an accurate segmentation technique for femoral head and proximal acetabulum and it can be applied as a tool in medical practice.     

柳南高速公路改扩建工程设计方案探讨

文章结合柳州至南宁高速公路改扩建工程项目情况,分析了该改扩建项目的技术难点和重点,阐述了改扩建工程设计的总体思路,并提出了相应的改扩建工程设计方案。     

Simulation of mixed gas formation for a spray-wall complex guided LPG direct injection engine

To obtain an ultralean air-fuel ratio and to reduce engine-out NOX and HC emissions induced by the richer mixture near the spark plug, a spray and wall complex guided combustion system has been developed by utilizing the fuel characteristics of LPG. The new combustion system configuration is optimized by using a commercial CFD code, FIRE V2013, and the reliability of the system has been experimentally demonstrated by Plane Laser-Induced Fluorescence (PLIF). The mixture formation in the new combustion system under part load (2,000 rpm) is numerically simulated. With an injection timing of 40°CA BTDC, the LPG spray which is injected from two upper holes, reaches the ignition point, and the other part of the LPG spray which is injected from the bottom hole, is directed to the ignition point through the vertical vortices at the same time. At the ignition timing of about 20°CA BTDC, the two-part mixtures have been shown to form a stable and richer stratified mixture around the ignition point, and the maximum global air-fuel ratio reaches to 60: 1.     

���˹���������������ɢ��������ʵ֤����

国家体育场作为北京奥运会的主会场成功地承担了开闭幕式和田径赛事任务。本文研究了其停车场车辆的交通疏散问题,制定了疏散方案。首先,分析了国家体育场停车场和泊位布局及车辆疏散的具体条件。其次,通过给定环境的场景和参数设定,对具体的奥运场馆停车场车辆的疏散方案进行了仿真和评价。最后,利用奥运会开幕式的车辆疏散实测数据进行了对比分析,在仿真中要员和贵宾车辆的总疏散时间为26min,而奥运会开幕式车辆疏散实测结果表明,全部要员、贵宾疏散完毕,共用时27min,从而验证了车辆疏散方案的准确性和实用性。     

Effect of ABCA1-V771M polymorphism on plasma lipid levels and its relationship with coronary atherosclerotic heart disease

Objective To explore the risk association of ABCA1-V771M polymorphism with coronary heart disease (CHD) in Hart nationality in Northwest of China. Methods With case-control study, ABCA1-V771M polymorphism was detected in 204 unrelated Hart nationality people in Northwest of China, and all the subjects by coronary angiography were grouped into 106 cases and 98 controls. The genotypes and alleles frequency distribution of ABCA1-V771M polymorphisms were analyzed by PCR-RFLP analysis, and the clinical statistics of serum lipids were compared and its effects of ABCA1-V771M polymorphism on the plasma lipid levels and coronary atherosclerotic heart disease were analyzed. Results The genotypic frequencies of ABCA1-V771M polymorphism matched well under Hardy-Weinberg equilibrium (P>0.05), V and M allelic frequencies were 33.3% and 66.7%. In comparison with VV VM genotype carriers, MM genotypes carriers had much lower plasma levels of HDL-C (P<0. 001) and much higher plasma levels of TG (P<0. 05). M allelic frequency in CHD group was significantly higher than V allelic frequency (P<0. 05). M allele was related with more severity of atherosclerosis in the coronary artery than V allele (P<0.05). However, there was no obvious difference in the incidence of AMI among carriers with three genotypes of ABCA1-V771M polymorphism (P>0.05). Conclusion ABCA1-V771M polymorphism was not only associated with the plasma levels of HDL-C and TG, but also related to the susceptibility and severity of coronary atheroselerotic heart disease. Moreover, M771 allele appeared to be atherogenie among Han population in Northwest of China.