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91.
沥青搅拌设备整机验收一般应针对主要作业性能指标进行。科学合理地确定验收项目及验收依据是验收工作的关键,根据实践经验,提出了一套切实有效的验收方法。 相似文献
92.
平地机施工时平整度的控制与施工工艺 总被引:1,自引:0,他引:1
以“二级公路”施工为分析点,对平地机的特点进行分析,对施工工艺加以总结,就如何提高平地机的使用效率,如何提高其施工过程的平整度,如何达到所规定的质量技术指标进行探讨。 相似文献
93.
中国和美国汽车保险比较——谈投保人对保险费率的影响 总被引:1,自引:0,他引:1
汽车保险是我国财产保险中份额最重的一项,随着中国汽车工业的迅猛发展,我国的汽车保险业也将迎来一个黄金期。但是与汽车王国美国相比较,我国汽车保险费率的厘定,更多地关注汽车本身,而忽略投保人这一主体因素,更多地关注人的因素,是加入WTO后的我国汽车保险人值得重视的一个话题。 相似文献
94.
现代轿车自动变速器技术分析 总被引:1,自引:0,他引:1
自动变速器作为现代汽车传动系统中一个十分重要的总成,对车辆诸多性能的提高起着重要的作用。世界轿车自动变速器技术的发展无疑反映了当今该项技术的潮流,自动变速器技术正朝着结构多挡化、性能高效化、换挡智能化和舒适化等方向发展。 相似文献
95.
96.
Neighborhood services,trip purpose,and tour-based travel 总被引:6,自引:0,他引:6
Communities are increasingly looking to land use planning strategies to reduce drive-alone travel. Many planning efforts aim to develop neighborhoods with higher levels of accessibility that will allow residents to shop closer to home and drive fewer miles. To better understand how accessible land use patterns relate to household travel behavior, this paper is divided into three sections. The first section describes the typical range of services available in areas with high neighborhood accessibility. It explains how trip-based travel analysis is limited because it does not consider the linked (chained) nature of most travel. The second section describes a framework that provides a more behavioral understanding of household travel. This framework highlights travel tours, the sequence of trips that begin and end at home, as the basic unit of analysis. The paper offers a typology of travel tours to account for different travel purposes; by doing so, this typology helps understand tours relative to the range of services typically offered in accessible neighborhoods. The final section empirically analyzes relationships between tour type and neighborhood access using detailed travel data from the Central Puget Sound region (Seattle, Washington). Households living in areas with higher levels of neighborhood access are found to complete more tours and make fewer stops per tour. They make more simple tours (out and back) for work and maintenance (personal, appointment, and shopping) trip purposes but there is no difference in the frequency of other types of tours. While they travel shorter distances for maintenance-type errands, a large portion of their maintenance travel is still pursued outside the neighborhood. These findings suggest that while higher levels of neighborhood access influences travel tours, it does not spur households to complete the bulk of their errands close to home. 相似文献
97.
Storage space allocation in container terminals 总被引:7,自引:0,他引:7
Chuqian Zhang Jiyin Liu Yat-wah Wan Katta G. Murty Richard J. Linn 《Transportation Research Part B: Methodological》2003,37(10):883-903
Container terminals are essential intermodal interfaces in the global transportation network. Efficient container handling at terminals is important in reducing transportation costs and keeping shipping schedules. In this paper, we study the storage space allocation problem in the storage yards of terminals. This problem is related to all the resources in terminal operations, including quay cranes, yard cranes, storage space, and internal trucks. We solve the problem using a rolling-horizon approach. For each planning horizon, the problem is decomposed into two levels and each level is formulated as a mathematical programming model. At the first level, the total number of containers to be placed in each storage block in each time period of the planning horizon is set to balance two types of workloads among blocks. The second level determines the number of containers associated with each vessel that constitutes the total number of containers in each block in each period, in order to minimize the total distance to transport the containers between their storage blocks and the vessel berthing locations. Numerical runs show that with short computation time the method significantly reduces the workload imbalance in the yard, avoiding possible bottlenecks in terminal operations. 相似文献
98.
Active Roll Control of Single Unit Heavy Road Vehicles 总被引:5,自引:0,他引:5
David J. M. Sampson David Cebon 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2003,40(4):229-270
Summary Strategies are investigated for controlling active anti-roll systems in single unit heavy road vehicles, so as to maximise roll stability. The achievable roll stability improvements that can be obtained by applying active anti-roll torques to truck suspensions are discussed. Active roll control strategies are developed, based on linear quadratic controllers. It is shown that an effective controller can be designed using the LQG approach, combined with the loop transfer recovery method to ensure adequate stability margins. A roll controller is designed for a torsionally flexible single unit vehicle, and the vehicle response to steady-state and transient cornering manoeuvres is simulated. It is concluded that roll stability can be improved by between 26% and 46% depending on the manoeuvre. Handling stability is also improved significantly. 相似文献
99.
This paper presents an attempt made to facilitate re‐scheduling of trains to minimize operational delays and accommodate uniform headways for off peak sub urban services subject to resource constraints such as locomotive availability, poor track conditions and stations without siding facilities. The paper describes the computer simulation model designed to optimize train schedules on single‐track rail lines. Using this simulation program it is possible to plan and optimize timetables for railway networks with train runs within short time periods for both single track and double track conditions. The paper describes the capabilities of presenting the results of the simulation runs. These include the time‐distance graph, the network with train movements, dialog boxes with information about selected trains. The programme is capable of changing the starting point, departure time, train destinations and adding or deleting a stop etc. from the user interface. Four objects of array variables are used in the simulation process to keep train and station data. Two object arrays are used for the train movements in up and down directions. The stations' data are stored in the other two object arrays. One of these arrays of stations contains all the stations of the line while the other one contains only the stations with siding facilities. A case study that covers a 61 km long single‐track line with 14 stations is presented to highlight the model capabilities. 相似文献
100.