桥面防水涂料在烟黄高速公路中的施工简介

从高等级公路桥梁桥面防水的必要性入手,介绍了高分子聚合物防水涂料的性能要求及施工方法。     

自动变速器控制技术研究

自动变速器的控制技术影响到变速器使用性能,主要介绍了电子控制变速器的各种控制功能。     

港口门机司机绩效考核系统设计

针对某港口企业下属门机队现行绩效考核和管理相对落后的状况提出了有效的改进策略。基于门机作业实时记录,采用Microsoft SQL2005数据库、VC＋＋6．0和水晶报表技术设计了一套司机作业绩效考核软件,实现了对现场采集数据的转换和存储,并结合作业票数据考核门机司机的作业量,自动生成每月的机械队员工工资报表,同时,港口企业通过司机绩效考核软件完成对生产数据的科学、有效的管理。     

基于因子分析法的公路运输绩效评价研究

公路运输是国民经济的基础产业,提高公路运输绩效是发展国民经济的根本途径。在构建公路运输绩效评价指标体系的基础上,利用2003年的调研统计资料,用因子分析法对全国各省市的公路运输系统绩效进行综合评价,指出影响道路运输系统绩效的主要因素,将各省的公路运输系统绩效进行比较,探索影响排名的因素,明确提高公路运输绩效的方向。     

Environmental and transport effects of warehouse relocationing: evidence from Norway

Reducing traffic volumes and CO2-emissions from freight transport has proven difficult in many countries. Although the increasing suburbanization of warehouses is seen as a relevant land use trend, comprehensive analyses of their impact remain scarce. This study uses real data in modeling transport, costs, environmental and modal effects from warehouse relocations around Oslo and Trondheim (Norway). Results indicate that for Oslo, traffic performance (ton-km), CO2-emissions, and transport costs increase following warehouse suburbanization. For Trondheim, transport performance and CO2-emissions increase less, while transport costs decrease marginally. We conclude that specific case characteristics (geography and trade patterns) are important in determining the strength and direction of effects, and expect that common concomitant developments (warehouse centralization and consolidation) would lead to more pronounced results. Our findings confirm some, but challenge other, findings from the relatively scarcely literature available. Finally, the study's more general insights and observations can help advance similar analyses beyond Norway.     

Fully autonomous vehicles: analyzing transportation network performance and operating scenarios in the Greater Toronto Area,Canada

Fully autonomous vehicles (AVs) have the potential to considerably change urban mobility in the future. This study simulates potential AV operating scenarios in the Greater Toronto Area (GTA), Canada, and assesses transportation system performance on a regional level. For each scenario, the base capacities of certain types of road links are modified to simulate the theoretical increase in throughput enabled by AV driving behavior. Another scenario examines driverless parking operations in downtown Toronto. Simulation results indicate that the increased attractiveness of freeways relative to other routes leads to slightly increased average travel distance as vehicles divert to access higher capacity road links. Average travel time is found to decrease by up to one-fifth at the 90% AV market penetration level. Concurrently, localized increases in congestion suggest that proactive transportation planning will be needed to mitigate negative consequences of AV adoption, especially in relation to induced demand for personal automobile travel.     

Categorizing bicycling environments using GPS-based public bicycle speed data

A promising alternative transportation mode to address growing transportation and environmental issues is bicycle transportation, which is human-powered and emission-free. To increase the use of bicycles, it is fundamental to provide bicycle-friendly environments. The scientific assessment of a bicyclist’s perception of roadway environment, safety and comfort is of great interest. This study developed a methodology for categorizing bicycling environments defined by the bicyclist’s perceived level of safety and comfort. Second-by-second bicycle speed data were collected using global positioning systems (GPS) on public bicycles. A set of features representing the level of bicycling environments was extracted from the GPS-based bicycle speed and acceleration data. These data were used as inputs for the proposed categorization algorithm. A support vector machine (SVM), which is a well-known heuristic classifier, was adopted in this study. A promising rate of 81.6% for correct classification demonstrated the technical feasibility of the proposed algorithm. In addition, a framework for bicycle traffic monitoring based on data and outcomes derived from this study was discussed, which is a novel feature for traffic surveillance and monitoring.     

Multi-objective optimization for asphalt pavement maintenance plans at project level: Integrating performance,cost and environment

Traditionally, asphalt pavement maintenance mainly considers pavement performance and cost and largely ignores the environment while substantial amount of environmental burdens are released in the process. In this study, a multi-objective optimization model was developed integrating the three elements in order to optimize the asphalt pavement maintenance plans at the project level. Pavement performance element was decided as the multiplier of pavement serviceability index and traffic volume. Cost element was represented by the net present value, including components of agency cost, vehicle operation cost and salvage value. Environmental element, integrating energy consumption, global warming potential, acidification potential and respiratory effects potential, was measured by the life cycle assessment model. A hypothetic asphalt pavement maintenance case study was conducted using the developed multi-objective optimization model and harvested 103 sets of feasible combinations of maintenance plans, each of which is non-dominated by the others. Trade-offs analysis was performed among the three objectives and visualized in both two- and three-dimension forms. It is found there is an opportunity of reducing the cost and environmental impacts to 80.3% and 77.8% and increasing the pavement performance to 146.6% compared to the base case. However, they are mutually compromised and cannot be reached simultaneously. The developed model reveals the quantitatively interactive relationship of the three objectives and helps optimize the asphalt pavement maintenance plans.     

电动汽车锂离子电池试验的安全要素分析

实验室标准化试验的条件比装车使用严酷,在汽车动力锂离子电池试验的过程中,实验室的安全是不可忽视的问题.基于实践和探索,介绍关于试验安全的要素和分析思路并讨论防护措施.     

冻融循环对不同塑性路基土剪切强度的影响研究

为了研究冻融循环对不同塑性路基土剪切强度的影响,通过室内三轴试验和冻融循环试验对3种塑性指数的土样进行了研究。结果得到:当冻融循环次数增加时,剪切强度随着塑性指标的增加而有所增大;当塑性指数相同时,剪切强度随冻融次数增加与围压增加改变各不相同,与冻融循环次数成反比,与围压成正比。并且冻融循环6~7次后,3种塑性指数土样的剪切强度的变化均会趋于平缓。