中英典型交叉口通行能力对比分析及应用

为了缓解日益严重的交通问题,寻求解决道路通行能力低下问题的有效方法,以提高道路利用率.本文通过采集英国3个路口和中国北京10个路口视频数据进行通行能力和饱和流量对比,分析中英差异和原因.在此基础上,定量分析非机动车对北京市交叉口绿灯损失时间的影响,以定量分析非机动车对信号交叉口通行能力和饱和流量的影响.对比结果表明：由于非机动车及行人干扰,中国城市道路交叉口道路利用率要比英国整体低10到20个百分点,这为解决中国城市道路利用率低的问题提供指导方向.最后,通过官园桥的实例,验证该研究成果的科学意义和应用意义.     

数值模拟在船型方案优选中的应用

随着计算机和CFD技术水平的提高,数值模拟所需时间逐渐缩短、准确度逐步提高,利用数值模拟作为一种辅助手段进行方案择优已经逐渐流行。本文利用商用软件对广船国际提供的某油船三种线型进行了设计和结构吃水工况下的数值计算,包括阻力、自航计算,并且根据ITTC推荐规程做了实船尺度下的数据分析;以实船尺度下保持目标航速所需要的收到功率最小为评判标准,通过对该船三个方案线型不同吃水情况下计算结果的比较分析,评价了线型方案的优劣。通过数值模拟结果与物理试验结果的比较分析,验证了本文计算方法可靠性和准确性,也展示了数值模拟在船型方案择优过程中的作用,可以用于综合评价不同方案线型的船舶水动力性能。     

蒸汽调节阀手自动转换装置优化及试验

对汽轮机蒸汽调节阀手动自动转换装置进行优化改进和试验研究,提高了装置的使用寿命以及汽轮机运行安全性和可靠性,具有重要意义。     

模糊优选理论在选择桥梁方案中的应用

针对现行优选桥梁方案方法上的不足,如难以将定量指标与定性因素综合量化评价、受主观因素影响大、误选的可能性较大等。笔者根据模糊优选理论建立和求解桥梁方案优选模型,结合实例介绍该方法的具体运用。实例研究表明:运用模糊优选理论优选桥梁方案能有效减少主观因素的影响,优选结果准确,方法简便实用。     

工程施工计划优化决策支持系统

针对工程施工进度的合理安排和资源的最优利用,从项目施工管理的角度出发,通过计算机人机交互系统,综合运用运筹学、经济学、工程科学、决策管理等理论,提出了工程施工计划优化决策支持系统,阐述了其功能、结构及主要模型,并开发了相应软件。该系统为工程施工计划编制者和现场管理人员提供了一种辅助管理与决策环境,是施工企业进行决策的有效技术手段。     

柴油机组合进气道布置位置优化研究

针对某型柴油机切向/螺旋组合进气道进气系统进行了稳态流场的数值模拟,分析了组合气道的流动特性,为进气道位置优化提供了依据;在不改变原机气道形状的基础上,通过稳流试验确定了最终进气道位置的优化方案,证实了流动数值模拟在气道优化中的指导作用。     

杭昱高速公路昱岭关隧道设计与施工方案优化

对杭昱高速公路昱岭关隧道的设计和施工进行了总结，根据公路隧道新奥法设计原理及新奥法施工程序和基本原则，针对昱岭关隧道设计与施工特点，并根据开挖围岩稳定情况及监控量测结果，及时调整设计支护参数和施工方案，保证了隧道施工质量和施工安全，而且加快了施工进度，节约工程投资，取得了良好的效果。     

Future electricity demand from battery‐powered vehicles

An important decision faced by airline schedulers is how to adapt the flight schedule and aircraft assignment to unforeseen perturbations in an established schedule. In the face of unforeseen aircraft delays, schedulers have to decide which flights to delay, and when delays become excessive, which to cancel. Current scheduling models deal with simple decision problems of delay or cancellation, but not with both simultaneously. But in practice the optimal decision may involve results from the integration of both flight cancellations and delays. In Part I of this paper, a quadratic programming model for the integration decision problem is given. The model can formulate the integration of flight cancellations and delays as well as some special cases, such as the ferrying of surplus aircraft and the possibility of swapping different types of aircraft. In this paper, based on the special structure of the model, an effective algorithm is presented, sufficient computational experiments are conducted and some results are reported. These show that we can expect to obtain a sufficiently good solution in terms of reasonable CPU time.     

Economic conditions for minibus usage in a multimodal feeder network

The introduction of minibuses into the transit fleets of some cities makes it more important than ever to investigate the economic and operating conditions of these vehicles for various transit and paratransit services. A high performance transit system is of great interest, owing to its desirable characteristics. However, it is not feasible to establish and use such a system all over a city. It is therefore necessary to support a high performance transit system with other modes to extend its area of operation (owing to higher demand) and also to connect those areas that are not covered by the high performance system to it. This paper considers the use of minibuses in the design of metro line feeders and to characterize the economic domain in which it is efficient to use them in a feeder network. Based on results from ant colony optimization, the performance measures of minibuses are compared with those of conventional buses to help make decision makers aware of the use and role of these vehicles. The study contradicts the common belief that, since minibuses require similar driver costs to those of conventional buses, it is not economical to use them in a transit fleet; in fact, it is shown that minibuses can displace conventional buses in some situations in a feeder network.     

丙烯酸泡棉胶带在汽车结构优化方面的应用

丙烯酸泡棉胶带在优化汽车结构方面已经成为了一种越来越重要的方式。为了更好地提供在汽车优化结构设计方面的选择,文章介绍了丙烯酸泡棉胶带的发展及其性能特点,针对汽车结构设计的优化,通过对丙烯酸泡棉胶带固定方式和传统机械固定方式的比较和分析,同时也通过两者在提高整车密封性能和降低整车质量方面的比较和分析进一步说明丙烯酸泡棉胶带在汽车内外饰连接固定的方式和汽车结构设计的方面提供了更加优化、更加经济和更加环保的选择。