新冠疫情影响下居民共享出行方式选择行为研究

为分析新冠疫情对共享出行方式选择行为的影响，针对传统出行、网约车、合乘、汽车分时租赁及共享自行车的多方式交通系统设计SP(Stated Preference)问卷；对于疫情前和疫情期间的出行方式选择分别构建基于面板数据的混合Logit模型，比较解释变量的影响差异，分析感知疫情严重程度和方式选择惯性的联合影响；基于弹性分析预测疫情背景下不同管控政策对应的出行方式分担率。结果表明：感知疫情严重程度对合乘和分时租赁影响显著，方式选择惯性对网约车、分时租赁及共享自行车影响显著；当感知疫情严重程度降低至30%~50%时，1.6~3.0倍的停车费调整策略可将私家车分担率降低至疫情前，此时，低密接的分时租赁具有主要替代作用；当感知疫情严重程度在60%以上时，提高合乘出行安全程度至1.4~3.6倍可恢复其分担率。     

带软时间窗的混合车队车辆路线问题的模型和算法研究

将典型的车辆路线问题扩展为综合考虑了客户具有间窗约束和中央仓库拥有多种类型配送车辆的情况。在构造了问题的数学模型后,着重阐述了求解本问题的TS算法设计过程。最后结合适应性记忆过程给出了TS算法的伪代码描述和一个算法。     

RESEARCH ON BUILT ENVIRONMENT FORM IN CITY AND TOWN

IntroductionIt is recognized that a vigorous period ofworldwide urbanization will be continued in 2 1 stcentury.Due to the impact of industrialization andglobalization of economy,many developing citiesand towns,which were full of regional and nation-al characteristics,are in the fading process. Peopleare often confused by the stereotyped environmentform and don't know where they are. The GeniusLoci has lost.Built environment,which is embodied mainlyby the city space and cityscape,is formed a…     

集佳公路采用动力触探法进行碎石上路基压实质量检测

简介动力触探法的仪器设备和原理。探讨利用动力触探法进行碎石土路基检测。介绍集佳段利用该方法进行碎石土路基质量评定的经验。     

网联车对抗神经网络跟驰模型

针对当前混行交通流场景下网联车对前车速度变化的实时性、安全性和车队稳定性较差的状况,提出一种由生成模型和辨别模型构成的网联车生成式对抗网络车辆跟驰模型(GANVFM).其中,生成模型提取跟驰参数中的前车速度、跟驰车速和相对车距计算生成加速度;辨别模型对生成模型生成的加速度参数进行相似度计算,并通过更新函数加以更新.采用...     

公路高边坡设计方案比选研究

针对现实工程中遇到的高边坡进行支护设计,分别对植草、框架植草和增加护坡道宽度进行分析计算,通过对不同方案从技术、稳定、经济和施工等因素进行分析,得出最优化的方案,为工程中类似的边坡治理提供借鉴和参考.     

适用于土石混填路基的智能压实技术应用研究

土石混填料为山区公路路基填筑最主要的原料,由于土石混填料级配差、不稳定等特点,难以控制土石混填路基压实质量.智能压实技术本质上是根据监测的振动响应获得智能压实测量值,识别或评估压实质量,并实现碾压过程的动态监控.针对土石混填路基压实质量常规评价指标的不足,文中研究适用于土石混填路基的智能压实测量值指标,依托某高速公路土...     

Modeling heterogeneous parking choice behavior on university campuses

Studies on campus parking indicate more severe problems and a wider range of characteristics than commercial parking because of limited parking places, special conditions, specific policies and enclosed space on university campuses. Heterogeneous characteristics are usually ignored in analyses of campus parking behavior. In this paper, a mixed logit model is applied to analyze parking choice behavior on a campus using data collected from a stated-preference survey of Tongji University, Shanghai, China. The heterogeneity of individuals with various sociodemographic characteristics is evaluated by interaction terms and random parameters. Comparison between the proposed approach and the conditional logit model shows that the results of the mixed logit model are more interpretable because they are not limited by the independence from irrelevant alternatives assumption. Key factors that have considerable effects on campus parking choices are identified and analyzed. Important regularities are also concluded from elasticity analyses. Finally, the campus is divided into two areas according to the walking distance to a new parking lot, and the modeling results show that area-specific policies should be established because the two areas have quite distinct parking choice features.     

Timetable optimization models and methods for minimizing passenger waiting time at public transit terminals

This paper focuses on developing mathematical optimization models for the train timetabling problem with respect to dynamic travel demand and capacity constraints. The train scheduling models presented in this paper aim to minimize passenger waiting times at public transit terminals. Linear and non-linear formulations of the problem are presented. The non-linear formulation is then improved through introducing service frequency variables. Heuristic rules are suggested and embedded in the improved non-linear formulation to reduce the computational time effort needed to find the upper bound. The effectiveness of the proposed train timetabling models is illustrated through the application to an underground urban rail line in the city of Tehran. The results demonstrate the effectiveness of the proposed demand-oriented train timetabling models, in terms of decreasing passenger waiting times. Compared to the baseline and regular timetables, total waiting time is reduced by 6.36% and 10.55% respectively, through the proposed mathematical optimization models.     

柴油-甲缩醛混合燃料喷雾的粒子动态分析研究

为研究代用燃料甲缩醛的喷雾机理,采用基于相位多普勒原理的粒子动态分析仪(PDA),研究了不同百分比的柴油-甲缩醛混合燃料喷雾的粒度场、速度场。试验结果表明,柴油添加甲缩醛后,雾化得到改善,喷雾轴线上的粒子轴向速度提高,但三者径向速度相差不大。