Commuting travel behavior focusing on the role of shared transportation in the wake of the COVID-19 pandemic and the Tokyo Olympics

To maintain life in the face of the COVID-19, people's lifestyles and travel behaviors must change. Accordingly, such changes have also occurred in the travel behavior for commuting purposes, especially during periods of severe congestion. The most typical example is the decrease in commuting travel due to telecommunication and other factors. Additionally, with the development of the sharing economy in recent years, the introduction of shared transportation has been rapidly expanding in the transportation sector, which may contribute to alleviating traffic congestion and other problems in the COVID-19 situation. In this study, we focused on the changes in travel behavior for commuting purposes during the COVID-19 period, including the time of the Tokyo Olympics, when traffic congestion was expected. The survey was conducted using a web-based questionnaire. In addition, to further promote changes in the travel behavior during the COVID-19 period, we analyzed the possibility of changes in the use of shared transportation arising from nudge effects of information provision and incentives. The results showed that the changes in commuting travel behavior were related to the awareness of COVID-19. Certain issues, such as a lack of ports and the widespread use of shared transportation need to be identified and resolved. Meanwhile, it was shown that the role of shared transportation for commuting purposes could be further improved by incentives and real-time information presentation about shared transportation.     

Predicting downgrade crash frequency with the random-parameters negative binomial model: Insights into the impacts of geometric variables on downgrade crashes in Wyoming

Road deaths, injuries and property damage place a huge burden on the economy of most nations. Wyoming has a high crash rate on mountain passes. The crash rates observed in the state is as a result of many factors mainly related to the challenging mountainous terrain in the state, which places extra burden on drivers in terms of requiring higher levels of alertness and driving skill. This study was conducted to investigate factors leading to crashes on Wyoming downgrades, with a focus on geometric variables. Traditionally, crash frequency analysis is conducted using count models such as Poisson or negative binomial models. However, factors that affect crash frequency are known to vary across observations. The use of a methodology that fails to take into account heterogeneity in observed and unobserved effects relating to roadway characteristics can lead to biased and inconsistent estimates. Inferences made from such parameter estimates may be misleading. This study employed the random-parameters negative binomial regression models to evaluate the impact of geometric variables on crash frequency. Five separate models were estimated for total, fatal/injury, property damage only (PDO), truck, and non-truck crash frequencies. Several geometric and traffic variables were found to influence the frequency of crashes on downgrades. These included segment length, vertical grade, shoulder width, lane width, presence of downgrade warning sign, vertical curve length, presence of a passing lane, percentage of trucks, number of lanes and AADT. The results suggest that segment length, lane width, presence of a passing lane, presence of a downgrade warning sign, vertical grade, and percentage of trucks are best modeled as random parameters. The findings of this study will provide transportation agencies with a better understanding of the impact of geometric variables on downgrade crashes.     

邢台至冀晋界段高速公路勘察设计要点

邢台-汾阳高速公路邢台-冀晋界段地形地质条件及邢台市周边城市路网规划布局复杂。文章通过对不良地质、工程物探、特殊土的勘察,解决了长大纵坡交通安全问题,路基防护、排水、取土等技术问题,体现出资源节约、环境美化、安全舒适、经久耐用、便于养护、经济合理的设计宗旨。     

Evaluating the use of an urban consolidation centre and electric vehicles in central London

The paper focuses on the role that can be played by urban consolidation centres (UCCs) in reducing freight traffic and its environmental impacts in towns and cities. It is based on the before and after evaluation of a trial led by a major stationery and office supplies company in which urban freight deliveries in central London made from a depot in the suburbs using diesel vehicles were replaced with the use of an urban micro-consolidation centre located in the delivery area together with the use of electrically-assisted cargo tricycles and electric vans. The results show that the total distance travelled and the CO₂eq emissions per parcel delivered fell by 20% and 54% respectively as a result of this delivery system. However, the evaluation has also indicated that the distance travelled per parcel rose substantially in the City of London delivery area as a result of the electric vehicles having far smaller load limits in both weight and volume compared with diesel vans. But, at the same time, the trial system was able to virtually eliminate CO₂eq emissions per parcel delivered in the City of London. The trial proved successful from the company's perspective in transport, environmental and financial terms. The company therefore decided to continue the operation beyond the end of the trial with it being officially launched during 2010.     

包头市城乡客运一体化规划研究

城乡客运一体化是城乡一体化的重要支撑、保障与体现。文章分析了城乡客运一体化的内涵,重点辨析了城乡旅客运输的不同形式及特点,并在深入挖掘包头市城乡社会经济及旅客运输特点和发展需求的基础上,提出城乡客运一体化规划目标和实施方案,以及规划实施的保障措施。     

Impact of COVID-19 on the Japanese travel market and the travel market of overseas visitors to Japan,and subsequent recovery

The spread of COVID-19 hit both the Japanese travel market and the foreign travel market to Japan, forcing travel-related businesses to shrink, temporarily suspend operations, or close down their businesses. However, Japanese people's desire to travel after the slowdown of COVID-19 remains and the desire of people from Asia, Europe, the United States, and Australia to travel to Japan is also high. The Japanese Government provides loans and other support measures to enable travel-related business operators to survive through the COVID-19 crisis. They advance measures to increase the benefit of accommodation facilities and tourism areas in preparation for the recovery period of travel demand. Although the situation is unpredictable as the mutation of the virus continues, under the assumption that the vaccination will progress worldwide and travel restrictions will be relaxed in the near future, this study examines the path and issues for the recovery of Japanese travel demand and foreign travel demand for overseas visitors to Japan.     

Development of an on-line model to predict the in-cylinder residual gas fraction by using the measured intake/exhaust and cylinder pressures

The in-cylinder RGF (residual gas fraction) of internal combustion engines for new combustion concepts, such as CAI (controlled auto ignition) or HCCI (homogenous charged compression ignition), is a major parameter that affects the combustion characteristics. Thus, measurement or prediction of the cycle-by-cycle RGF and investigation into the relation between the RGF and the combustion phenomena are critical issues. However, on-line prediction of the cycle-by-cycle RGF during engine testing is not always practical due to the requirement of expensive, fast response exhaust-gas analyzers and/or theoretical models that are just too slow for application. In this study, an on-line model that can predict the RGF of each engine cycle and cylinder during the experiment in the test cell has been developed. This enhanced model can predict the in-cylinder charge conditions of each engine cycle during the test in three seconds by using the measured dynamic pressures of the intake, exhaust, and cylinder as the boundary conditions. A Fortran77 code was generated to solve the 1-D MOC (method of characteristics). This code was linked to Labview DAQ as a form of DLL (dynamic link library) to obtain three boundary pressures for each cycle. The model was verified at various speeds and valve timings under the CAI mode by comparing the results with those of the commercial code, GT-Power.     

农村牧区公路建设资金使用中存在的问题与对策

随着经济的不断发展,国家把农村基础设施建设纳入到重要的民生工程中,不断加大投资补助力度,加快发展步伐。但由于近几年来受美欧债务危机影响,国内物价上涨速度过快,致使农村公路建设成本不断增加,资金筹集的多元化,导致在使用中出现许多问题。因此,采取有效措施,加强和规范建设资金管理迫在眉睫。文章结合内蒙古自治区农村牧区公路建设资金在使用和管理中存在的问题,提出解决思路和对策。     

A combined use of phase plane and handling diagram method to study the influence of tyre and vehicle characteristics on stability

This paper deals with in-curve vehicle lateral behaviour and is aimed to find out which vehicle physical characteristics affect significantly its stability. Two different analytical methods, one numerical (phase plane) and the other graphical (handling diagram) are discussed. The numerical model refers to the complete quadricycle, while the graphical one refers to a bicycle model. Both models take into account lateral load transfers and nonlinear Pacejka tyre–road interactions. The influence of centre of mass longitudinal position, tyre cornering stiffness and front/rear roll stiffness ratio on vehicle stability are analysed. The presented results are in good agreement with theoretical expectations about the above parameters influence, and show how some physical characteristics behave as saddle-node bifurcation parameters.     

Examining the influence of network,land use,and demographic characteristics to estimate the number of bicycle-vehicle crashes on urban roads

The focus of this paper is to examine the influence of network, land use, and demographic characteristics on the number of bicycle-vehicle crashes, and to develop area-level bicycle-vehicle crash estimation models (safety performance functions) for urban roads. Mecklenburg County in the State of North Carolina was considered as the study area. The reported bicycle-vehicle crash data, from 2010 to 2015, along with the network, land use, and demographic characteristics data were obtained from the local agencies. Data within a one-mile buffer of 119 selected locations was then captured. Data for 99 selected locations were used for the modeling purpose, while data for the remaining 20 selected locations were used for validating the models. Six alternate models were developed, considering various combinations of explanatory variables that are not correlated with each other. As the bicycle-vehicle crash dataset used in this research was observed to be over-dispersed (variance greater than the mean), Negative Binomial log-link distribution-based models were developed. The validation dataset was used to compare the estimated number of bicycle-vehicle crashes from each model with the actual number of bicycle-vehicle crashes. The results obtained from the analysis and modeling suggest that bicyclists are more often involved in crashes while traveling on segments with no bicycle lane, the traffic light, 45 mph as the speed limit, and in commercial activity, research activity, institutional, multi-family residential (densely populated), and heavy industrial areas. The computed Moran's Index values indicate weak to no spatial correlation between the residuals of each model. However, the residuals seem to depend on the area type and the number of bicycle-vehicle crashes.     

港口仓储类上市公司募集资金投向研究

归纳港口仓储类上市公司募集资金投向的基本情况，从募集资金的投向和使用效率的角度对上市公司募集资金的使用进行比较研究，总结出港口仓储行业募集资金的投向特点，并在提高募集资金使用效率方面提出建议。     

高陡地形泡沫混凝土轻质路堤承载特性分析

以贵州省铜仁市G354石阡香树园至河坝公路改扩建工程中采用泡沫混凝土换填路堤为实例,运用Midas/GTS软件对高陡地形泡沫混凝土路堤置换全过程进行数值分析,对置换过程中路堤的应力应变特性及不同设计方案工后沉降进行研究。结果表明:使用泡沫混凝土进行高陡地形路堤置换对控制路堤工后沉降的效果显著,能有效防止地基表面及路面不均匀沉降的发生。     

采用改进的集总平均经验模态分解法的内燃机气门拍击激励与燃烧激励分离的研究

提出了一种改进的集总平均经验模态分解(M-EEMD)方法,并阐述了其基本原理。通过仿真试验,证实了M-EEMD不仅能够很好地解决经验模态分解(EMD)中模态混叠问题,而且能够抑制集总平均经验模态分解(EEMD)的噪声残余和模态分裂等问题。作为实例,对一个4缸4冲程内燃机气缸盖罩的振动信号进行M-EEMD分解,并对分解得到的IMF分量进行时频分析。结果表明M-EEMD能够成功地将内燃机气门拍击引起的机械激励成分与燃烧激励成分分离。     

事故多发点鉴别本质及基于BP神经网络的鉴别方法研究

首先对常规事故多发点鉴别方法进行了分析和评述,并通过实例揭示了多发点的鉴别本质。在此基础上,建立了基于三层BP神经网络的城市干道路段事故多发点鉴别模型。该模型考虑了交通事故7个方面的影响因素,并能将常规鉴别方法不易识别出的多发点鉴别出来。其次,应用哈尔滨市市区430个干道路段上1999年至2004年发生的13764起交通事故数据及关联因素数据,对神经网络的权值和偏置值进行了标定,并应用该模型进行了事故多发路段鉴别。最后,分别应用了事故次数概率分布法、矩阵法和质量控制法对430个路段进行了多发点鉴别,并对鉴别结果进行了对比分析。     

PID控制在电控汽油机λ闭环控制中的应用及相关参数的标定

先对PID控制的基本原理进行说明 ,然后阐述PI控制在电控汽油机λ闭环控制中的应用 ,最后以采用M3.8.2系统的某 3缸机为例 ,说明λ闭环控制参数的匹配标定 ,同时给出台架匹配结果。     

潼西改扩建工程路堤地震动力响应分析

为分析在地震荷载作用下路堤的动力响应,以潼西改扩建工程为依托,运用MIDAS/GTS有限元程序建立潼西高速公路改扩建工程数值计算分析模型,分析了公路路面的水平和竖向位移响应和路堤边坡面动力响应。结果表明:在地震荷载作用下,距旧路中心距离越近,最大水平和竖向位移越小;新旧路基结合部产生明显的相对水平位移,路面发生断裂破坏的概率最大;同一地震荷载作用下,不同高程路堤的加速度的放大系数并不相同,随着高程的增加,放大系数整体上逐渐变大;当路堤坡顶观测点出现水平位移峰值时,坡面其它各观测点同样出现水平位移峰值,坡顶观测点的水平位移和加速度峰值并不同步,水平位移峰值滞后于加速度峰值。     

超声声速法检测柴油机蠕铁气缸盖蠕化质量

阐述了超声声速法检测柴油机蠕铁气缸盖蠕化质量的基本原理 ,蠕化率与声速的关系 ,并对影响声速的其他因素进行了分析 ,实现了用超声声速法对柴油机蠕化气缸盖蠕化质量进行快速检测。     

中标企业挪用专用资金的原因分析和后果影响

分析了专款专用的公路建设资金被中标施工企业挤占挪用的原因,以及挤占挪用后对建设项目所造成的不良后果和给社会带来的负面影响。