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61.
路网可靠度模型的研究与拓展 总被引:10,自引:0,他引:10
回顾了路网可靠度模型的研究进展:包括不同的可靠度指标、模型以及算法。在分析传统可靠度模型优缺点的基础上,提出将随机网络平衡模型用于路网可靠度分析。 相似文献
62.
高速公路合流区上匝道混合车流通行能力经验计算法 总被引:2,自引:0,他引:2
研究高速公路合流区上匝道混合车流的通行能力的计算问题。利用已有的高速公路合流区外侧车道交通特征分析结论,推求在外侧车流不同车头时距分布特征下的上匝道混合车流汇合概率模型。运用回归技术和统计方法,建立了加速车道合流点分布概率的实测经验模型。对可接受间隙理论的原型进行了形式上的修正,最终建立高速公路合流区上匝道的混合车流通行能力经验模型,它是主路交通量、匝道交通量、加速车道长度、匝道混合车流比例以及各自的临界间隙和随车时距的函数。最后结合实例介绍经验模型的数值积分求解方法,并证实该经验计算方法具有较高的实效性和可操作性。 相似文献
63.
64.
随着运输结构调整的不断深入,"公转铁"运量持续增加,我国铁矿石运输发展对铁路货运增量具有重要意义.阐述我国铁矿石市场产需运现状,分析铁矿石铁路运输情况,针对当前铁路铁矿石运输存在的问题,提出我国铁路铁矿石运输发展对策措施,即:加强港口后方通道衔接,提高海铁联运比重;推进企业专用线建设,强化铁路"门到门"服务;积极推进"... 相似文献
65.
为提升昆明局集团公司卸车能力,满足全路货运装车需求,阐述卸车能力影响因素,从系统角度构建铁路三级服务卸车系统,包括运输通道子系统、枢纽作业子系统与货运站点作业子系统.针对昆明局集团公司卸车能力紧缺的现状,分析各级服务子系统的能力,提出相应的能力提升措施,并分析其效果.经研究可知,通过实施运输组织优化、车流径路调整、货运... 相似文献
66.
在崇明生态岛的建设背景下,亟待发展绿色交通。基于岛屿绿色交通案例分析,归纳总结了绿色交通发展经验;基于问卷调查,分析了崇明生态岛的交通需求;探讨提出了崇明生态岛绿色交通系统建设要求与规划策略,给出了绿色交通发展的实施建议。 相似文献
67.
Masaru Tsujimoto Takashi Uehiro Hiroshi Esaki Takeshi Kinoshita Ken Takagi Susumu Tanaka Hiroshi Yamaguchi Hideo Okamura Masuho Satou Yoshimasa Minami 《Journal of Marine Science and Technology》2009,14(1):89-103
To acquire the wind energy of the oceans, a sailing wind farm has been proposed. The wind farm considered is composed of a
semisubmersible floating structure, 11 windmills, four sails, six thrusters, and storage for hydrogen. To maximize the acquired
energy, an effective algorithm to search for optimum routes was developed. The algorithm is based on the fact that beam winds
yield a maximum of acquired energy. This feature reduces the computation time, and, consequently, efficient route optimization
becomes possible in a reasonable time. After setting an operational area for the wind farm, navigation simulations for a 1-year
period were carried out. A numerical weather forecast was used as well as the responses of the floating structure, such as
the speed of the structure, the output power of the windmills, and the time of course changes. In the simulation, the wind
farm evades rough seas to avoid structural damage, and an optimum route is searched for. The capacity factor of the system
was used to evaluate the efficiency of the optimized routes. From the simulations, the maximum capacity factor achieved was
42.6%. The dependency of the capacity factor on the initial position of the wind farm was also examined. It was shown that
offshore from Sanriku in northeastern Japan is an area suited to the operation of the wind farm. The effect of the initial
position on consecutive periods of operation is discussed. 相似文献
68.
Cooperative Adaptive Cruise Control (CACC) systems have the potential to increase roadway capacity and mitigate traffic congestion thanks to the short following distance enabled by inter-vehicle communication. However, due to limitations in acceleration and deceleration capabilities of CACC systems, deactivation and switch to ACC or human-driven mode will take place when conditions are outside the operational design domain. Given the lack of elaborate models on this interaction, existing CACC traffic flow models have not yet been able to reproduce realistic CACC vehicle behaviour and pay little attention to the influence of system deactivation on traffic flow at bottlenecks. This study aims to gain insights into the influence of CACC on highway operations at merging bottlenecks by using a realistic CACC model that captures driver-system interactions and string length limits. We conduct systematic traffic simulations for various CACC market penetration rates (MPR) to derive free-flow capacity and queue discharge rate of the merging section and compare these to the capacity of a homogeneous pipeline section. The results show that an increased CACC MPR can indeed increase the roadway capacity. However, the resulting capacity in the merging bottleneck is much lower than the pipeline capacity and capacity drop persists in bottleneck scenarios at all CACC MPR levels. It is also found that CACC increases flow heterogeneity due to the switch among different operation modes. A microscopic investigation of the CACC operational mode and trajectories reveals a close relation between CACC deactivation, traffic congestion and flow heterogeneity. 相似文献
69.
70.
邵怀高速公路边坡生态恢复植物种类选择——护坡植物层次分析法(AHP)优选试验研究 总被引:1,自引:0,他引:1
对适宜于邵怀高速公路边坡生态恢复的24种植物进行层次分析法(AHP)优选实验研究,旨在找出邵怀高速公路边坡生态恢复的最佳植物种类。研究结果表明:紫花苜蓿、狗牙根、马尾松、刺槐、多花木兰、紫穗槐、胡枝子等7种植物最适合邵怀高速公路边坡生态防护。 相似文献