富水性软弱Ⅵ级围岩段隧道开挖支护施工技术

某项目工程地质和水文地质条件复杂,变化明显,尤其是区间隧道围岩级别由Ⅱ级过渡到Ⅵ级,施工方法变化频繁.安全、快速通过富水性软弱Ⅵ级围岩段是隧道施工中的重点和难点.通过分析该段落的具体地质特点,提出相应对策和施工任务;在此基础上,探讨了开挖支护技术施工要点.     

基于改进GM（1,1）的长江干线水位预测方法研究

针对长江干线水位预测建模复杂、数据不全的问题,利用长江干线真实历史水位观测数据,基于灰色系统GM（1,1）模型,研究贫数据下长江干线水位预测.根据灰色系统中数据越近越有价值跟拟合曲线为指数曲线的特点,通过重新构造生成序列和重新定义初始边界条件对GM（1,1）模型进行优化并对最终结果进行分析,得出优化后的模型能更准确的预测水位的结论.     

基于驾驶模拟实验的层级式驾驶行为安全模型研究综述

针对驾驶行为的研究,从理论层面总结了国内外驾驶行为模型的演变发展过程,进而从应用层面上介绍了各种干预因素(分车载设备因素和非车载设备因素2类)对驾驶行为的影响.由于目前利用驾驶模拟器研究干预因素对驾驶行为的影响存在行为分析单一化、缺乏系统性的缺陷,据此提出了基于驾驶模拟实验的层级式驾驶行为安全模型,根据驾驶环境的复杂度及驾驶员涉及交通事故的可能性将驾驶行为按低、中、高3个风险层级分类,分别为基本车辆控制行为、在复杂交通环境中的动态决策行为以及在紧急交通状况中的避祸行为.利用该模型可以对干预因素影响下的驾驶行为安全进行系统全面的分析和评估.     

基于驾驶人分心影响程度的驾驶分心任务评级

为了进行驾驶分心任务评级,以选择反应判断检测和处置判断检测为试验平台,分析分心任务对驾驶人的影响.对13名被试驾驶人施加分心任务,包括视线遮挡、交谈、回忆、数学计算及部分任务的组合,并将各种分心状态下的反应时间及操作错误次数与无分心任务时进行对比.研究表明,在无驾驶操作的情况下,视线偏离1 s和交谈所产生的分心对驾驶人反应时间和操作准确度影响的差异不显著;认知分心任务比视觉分心任务产生更高的精神负荷;视觉分心与认知分心形成的复合分心任务对驾驶人的反应时间和操作准确度影响最大;基于对驾驶人的影响程度,可将常见分心试验任务大致划分为5个等级,依次为:无分心,视觉分心1 s/交谈,回忆,视觉分心3 s/计算,复合分心.     

盐邵船闸高水位系船设施应急改造研究

南水北调东线工程正式运行后,盐邵船闸上游长期处于高水位,闸室系船设施不能满足大型船舶高水位系缆要求。文中分析了过闸大型船舶的尺度、系缆特点,对船闸闸室结构安全进行验算,研究优化闸室高水位系船设施应急改造方案,取得了良好的使用效果。     

Data mining using regularized adaptive B‐splines regression with penalization for multi‐regime traffic stream models

This paper presents a new data mining method that integrates adaptive B‐spline regression and traffic flow theory to develop multi‐regime traffic stream models (TSMs). Parameter estimation is implemented adaptively and optimally through a constrained bi‐level programming method. The slave programming determines positions of knots and coefficients of the B‐spline by minimizing the error of B‐spline regression. The master programming model determines the number of knots through a regularized function, which balances model accuracy and model complexity. This bi‐level programming method produces the best fitting to speed–density observations under specific order of splines and possesses great flexibility to accommodate the exhibited nonlinearity in speed–density relationships. Jam density can be estimated naturally using spline TSM, which is sometimes hardly obtainable in many other TSM. Derivative continuity up to one order lower than the highest spline degree can be preserved, a desirable property in some application. A five‐regime B‐spline model is found to exist for generalized speed–density relationships to accommodate five traffic operating conditions: free flow, transition, synchronized flow, stop and go traffic, and jam condition. A typical two‐regime B‐spline form is also explicitly given, depending only on free‐flow speed, optimal speed, optimal density, and jam density. Copyright © 2013 John Wiley & Sons, Ltd.     

Traffic signal timing problems with environmental and equity considerations

Traffic signal timings in a road network can not only affect total user travel time and total amount of traffic emissions in the network but also create an inequity problem in terms of the change in travel costs of users traveling between different locations. This paper proposes a multi‐objective bi‐level programming model for design of sustainable and equitable traffic signal timings for a congested signal‐controlled road network. The upper level of the proposed model is a multi‐objective programming problem with an equity constraint that maximizes the reserve capacity of the network and minimizes the total amount of traffic emissions. The lower level is a deterministic network user equilibrium problem that considers the vehicle delays at signalized intersections of the network. To solve the proposed model, an approach for normalizing incommensurable objective functions is presented, and a heuristic solution algorithm that combines a penalty function approach and a simulated annealing method is developed. Two numerical examples are presented to show the effects of reserve capacity improvement and green time proportion on network flow distribution and transportation system performance and the importance of incorporating environmental and equity objectives in the traffic signal timing problems. Copyright © 2013 John Wiley & Sons, Ltd.     

自适应公交优先控制交叉口平均延误分析

以自适应公交信号优先控制交叉口为研究对象,提出了全新自适应公交信号优先控制交叉口车辆平均延误计算模型。并运用仿真测试平台,对该信号控制交叉口车辆平均延误进行了仿真分析。仿真结果表明：较常规信号控制方法,自适应公交信号优先配时虽然有助于减少公交行车延误,但是对道路交通系统中的其他车辆通行会造成很大的干扰,对整个交叉口通行能力的影响不一定是正面的。车辆平均延误分析对公交优先策略的具体实行方式、城市交叉口信号控制算法优化及其服务水平的提升具有良好的指导作用和借鉴意义。     

铝合金-铝-钢复合过渡接头修换工艺探讨

文章详细分析了铝合金-铝-钢复合过渡接头焊接后在铝钢复合面产生开裂的原因,并结合某型高速船的建造,提出了针对开裂问题所采取的修换措施和焊接注意事项,为今后该类船舶在维修过程中,提供了宝贵的经验和参考依据.     

黄河大河家至寺沟峡河段设计最低通航水位的推求

黄河大河家—寺沟峡河段受在建的大河家水电站和已建的寺沟峡水电站综合调节作用,河段水文条件变化复杂,要对该河段进行经济合理的整治开发必须以确定合理的设计最低通航水位为保证。结合枢纽的运行特征,建立一维数学模型对本河段设计最低通航水位进行研究,从而得到合理的设计最低通航水位。