地下连续墙墙幅缺口加固处理

该文分析了某地下连续墙墙幅缺口产生的原因,提出了施工解决的方法。通过基坑开挖过程中信息监测数据的分析,证明了处理方法的有效性和正确性,可供今后类似工程的施工作参考。     

行人穿越机动车流的平均临界间隙分析方法

通过研究行人穿越机动车流的平均临界间隙．对所观测的行人穿越间隙数据进行归纳分析,得出可接受穿越间隙的正态分布函数N（4.86,1．72）,并通过三种不同的方法逐一计算出平均临界间隙,可为今后的行人延误时间、通行能力以及与车辆之间的冲突分析研究提供解决方案。     

窄间隙焊缝跟踪电弧传感方法及特性研究

为了推广应用高效高质量的窄间隙电弧焊方法，迫切需要解决焊缝跟踪问题。针对新型高速旋转电弧焊接工艺，建立了一种窄间隙焊缝跟踪电弧传感检测方法及系统，并分析了电弧传感器的工作特性。试验结果表明：通过计算电弧旋转中心前点两侧一定区域内电弧电流（或电压）信号的积分差，旋转电弧传感系统能够有效地检测出焊缝偏差，其传感检测灵敏度受电弧电信号积分域和被检电信号种类（电弧电流或电压）等影响。     

Measuring the technology gap and logistics performance of individual countries by using a meta-DEA–AR model

This study presents an alternative approach to evaluate the efficiency of the logistics performance index (LPI) of individual countries. This study considers the differences among technology groups by classifying and comparing the countries as high-income Organization for Economic Co-operation and Development (OECD), high-income non-OECD, upper-middle-income, lower-middle-income, and low-income countries. The meta-frontier data envelopment analysis with assurance regions (Meta-DEA–AR) model is proposed to evaluate LPI scores and differences accurately among groups. For conformity with the ranking of original World Bank LPI, the assurance region of each logistics indicator is obtained by a regression model. The results show that the LPI rankings obtained by the proposed model are very comparable to those of World Bank LPI. Without distorting the rankings, the results offer several managerial suggestions for those countries with inefficiency in their LPIs.     

Pedestrian gap acceptance for mid-block street crossing

Abstract

This paper investigates pedestrians' traffic gap acceptance for mid-block street crossing in urban areas. A field survey was carried out at an uncontrolled mid-block location in Athens, Greece. Pedestrians' decisions and traffic conditions were videotaped in terms of the size of traffic gaps rejected or accepted, waiting times and crossing attempts and vehicle speeds. A lognormal regression model was developed to examine pedestrian gap acceptance. It was found that gap acceptance was better explained by the distance from the incoming vehicle, rather than its speed. Other significant effects included illegal parking, presence of other pedestrians and incoming vehicles’ size. A binary logistic regression model was developed to examine the effect of traffic gaps and other parameters on pedestrians' decisions to cross the street or not. The results reveal that this decision is affected by the distance from the incoming vehicles and the waiting times of pedestrians.     

交叉口右转机动车穿越决策BP仿真模型及灵敏度分析

机非相互穿越模型是信号交叉口混合交通微观仿真系统中反映机动车和自行车相互影响的核心模型. 为了描述交叉口处机动车穿越自行车流的决策行为,分析了两相位信号交叉口右转机动车穿越邻道直行自行车的微观行为,提出了基于BP神经网络的机动车穿越决策模型. 以北京2个交叉口调查数据为基础,对该模型验证并与Logistic模型比较,结果表明BP模型优于Logistic模型且具有较好的预测精度. 根据所建模型的映射关系计算出系统输出对输入参数的一阶灵敏度矩阵,灵敏度分析结果表明,自行车提供给机动车的穿越间隙是影响机动车穿越决策行为的决定性因素,且间隙在2.76s～2.96s变动时对机动车穿越决策行为影响最大.     

无信号控制路口通行能力仿真分析

在无信号灯控制路口处,按照可接受间隙理论,分析主路不同流量下对次路通行能力的影响,并对不同主路车流进行比较,找到对次路造成阻碍作用的主路车流之间的定量关系,分析当次路对向车流量变化时,这种定量关系变化趋势,从而为设置信号灯提供依据.     

道路车辆不良汇入驾驶行为的模型构建

针对当前国内关于不良汇入驾驶行为模型研究的空白,从概率统计和博弈论角度量化分析该行为。基于哈尔滨市高峰和平峰时段的定点视频调查数据,分析了汽车不良汇入驾驶行为的基本统计特性,给出了累计频率分布模型。研究结果表明当临界汇入间隙时间不足4S时,车辆汇入行为可界定为不良行为。进而,引入双人混合战略模型,从纳什均衡角度分析了支路汇入主路不良行为的发生概率。     

带壳有隙TNT炸药包的水下爆炸

裸炸药和有壳炸药空中爆炸的对比研究相当多,并且有了一致的结论;但对于水下带壳药包的爆炸少有研究,水中兵器水下爆炸破坏力都采用裸药的533公式.本文研究了这样的问题,并也研究了当柱形装药与壳体间留有间隙的情况.结论是水下爆炸时采用裸药的公式来计算一次冲击波峰值压力会带来一定的偏差,并且留有间隙虽然削弱了一次冲击波能量,但并不见得明显地增大了气泡脉动能量.     

中国产业国际竞争力问题探讨

在经济全球化趋势下,国家之间的竞争突出的表现在由产业国际竞争力所体现的经济实力的较量。提升产业国际竞争力,是各个国家都在思考的问题。分析了中国产业国际竞争力不足和影响制约中国产业国际竞争力的内在与外在因素,提出了应对措施。