全文获取类型
收费全文 | 116篇 |
免费 | 9篇 |
专业分类
公路运输 | 31篇 |
综合类 | 22篇 |
水路运输 | 27篇 |
铁路运输 | 30篇 |
综合运输 | 15篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 5篇 |
2020年 | 5篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 3篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 9篇 |
2012年 | 14篇 |
2011年 | 8篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 3篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 3篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有125条查询结果,搜索用时 27 毫秒
101.
The complexities of urban transportation networks where multiple modes with different characteristics and needs travel in combination with constraints on space and funding make the sustainable management of these systems a challenge. In order to improve transit service, space (e.g., dedicated bus lanes) and time (e.g., transit signal priority strategies) Transit Preferential Treatments (TPT) are deployed to improve transit operations. The objective of this paper is to develop an analytical model that allows for a person-based evaluation of alternative TPTs when considered individually and in combination. In particular, the analytical model is developed to assess person delay and person discharge flow at any intersection that is part of a signalized arterial, where auto arrivals are in platoons. The performance of TPTs is evaluated using both the analytical model and through microsimulation tests on two intersections of San Pablo Avenue in Berkeley, CA. Space TPTs such as dedicated bus lanes and queue jumper lanes are beneficial in reducing bus person delay when provided in addition to the existing lanes; however, the effectiveness of time TPTs such as green extension depends on the level of auto demand in combination with signal settings. Changes in person discharge flow are not significant for any of the treatments tested with the exception of the bus lane substitution with and without green extension, which led to a significant decrease in person discharge flow. Increased bus frequency increases the effectiveness of transit signal priority in reducing total and bus person delay. The analytical model results produce ranking outcomes that are comparable with the microsimulation ones and therefore, the model may be used for a quantitative evaluation of TPTs without the need for data intensive and time consuming calibration efforts required for microsimulation models. The developed model can be used to guide infrastructure and investment decisions on where such TPTs should be implemented and under what conditions space TPTs should be combined with time TPTs to improve person mobility. 相似文献
102.
We propose a novel real-time network-wide traffic signal control scheme which is (1) applicable under modern data technologies, (2) flexible in response to variations of traffic flows due to its non-cyclic feature, (3) operable on a network-wide and real-time basis, and (4) capable of considering expected route flows in the form of long-term green time ratios for intersection movement. The proposed system has a two-level hierarchical architecture: (1) strategy level and (2) control level. Considering the optimal states for a long-term period found in the strategy level, the optimal signal timings for a short-term period are calculated in the control level which consists of two steps: (1) queue weight update and (2) signal optimization. Based on the ratio of the cumulative green time to the desired green time is the first step to update the queue weights, which are then used in the optimization to find signal timings for minimum total delay. A parametric queue weight function is developed, discussed and evaluated. Two numerical experiments were given. The first demonstrated that the proposed system performs effectively, and the second shows its capability in a real-world network. 相似文献
103.
104.
105.
106.
107.
针对编组站尾部作业压力大、事故隐患多等问题,本文阐述了在编组站自动调速系统中应用尾部监控系统的重要性和必要性,简单介绍了系统发展经历的阶段和实施步骤,概括说明了系统的组成结构及主要功能,同时展望了监控系统未来的发展以及其在编尾调速自动化和尾部安全作业生产应用中的广阔发展前景。 相似文献
108.
黄河口尾闾河道断面形态的萎缩调整规律研究 总被引:1,自引:0,他引:1
采用实测资料分析和理论探讨相结合的方法,研究了水沙过程变异条件下,黄河口尾闾河道断面形态萎缩调整规律。研究结果表明,1986年后,黄河口水沙过程发生显著变异,尾闾河道断面形态萎缩十分明显,平滩面积大幅度减小,平滩宽深比有所增大;2002年后,小浪底水库实施调水调沙运用,黄河口水沙过程变异有所缓解,尾闾河道断面形态萎缩有所恢复,平滩面积明显增大,平滩宽深比大幅度减小,断面形态朝着窄深方向调整。通过引入尾闾河道断面形态萎缩的判别指标,可解决治理尾闾河道萎缩缺乏控制标准的问题。 相似文献
109.
介绍了800MHz列尾远程无线跟踪管理系统原理、关键技术、系统构成,以及工作过程、特点和技术指标等内容。 相似文献
110.
基于多功能车辆总线的城市轨道交通车辆数据采集系统 总被引:1,自引:0,他引:1
为了在地铁车辆运行过程中能够有效地监测车辆的运行状态,设计了基于MVB(多功能车辆总线)的城市轨道交通车辆数据采集系统。简要说明了数据采集系统需要完成的主要功能,同时对各功能模块进行了详细的介绍。给出了系统各组成部分详细的硬件电路设计,并对车辆数据采集系统中数据处理的流程进行了详细设计。 相似文献