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891.
892.
Sibok Lee Raymond A. Krammes John Yen 《Transportation Research Part C: Emerging Technologies》1998,6(5-6)
This paper documents a fuzzy-logic-based incident detection algorithm for signalized urban diamond interchanges. The model is capable of detecting lane-blocking incidents whose effects are manifested by patterns of deterioration in traffic conditions that require adjustments in signal control strategies. As a component of a real-time traffic adaptive control system for signalized diamond interchanges, the algorithm feeds an incident report (i.e., the time, location, and severity of the incident) to the system's optimization manager, which uses that information to determine the appropriate signal control strategy.The performance of the model was studied using a simulation of an actual diamond interchange. The simulation study evaluated the model's performance in terms of detection rate, false alarm rate, and mean time to detect. The model's performance was encouraging, and the fuzzy-logic-based approach is considered promising. 相似文献
893.
介绍淮安三线船闸基坑降排水的方法,并对降水过程中水位监测结果进行分析,同时阐述了降水对周围建筑物影响并对相关处理方法进行探讨。 相似文献
894.
Rachel L. Milford Julian M. Allwood 《Transportation Research Part D: Transport and Environment》2010,15(2):61-72
This paper investigates the CO2 impact of current and future UK rail track and estimates the material, process and transport emissions associated with construction, maintenance and end-of-life activities for designs at high and low traffic loads. Analysis shows that for current track configurations, track with concrete sleepers has the lowest CO2 impact, followed by steel, hardwood and softwood. Several potential future rail track designs have been analysed including embedded rail and double and quadruple-headed rail. All future track designs have a lower impact than current designs, but this improvement is more marked at high traffic loads. Up to a 40% reduction in CO2 impact could be achieved if the UK rail network was to move from conventional track design to a double-headed embedded rail design. Key levers for reducing the CO2 impact of track are identified as service life extension, traffic load reduction and the selection of low impact track designs. 相似文献
895.
为了提升数字化造船的科学性,提出基于知识库的舰船智能化设计系统,采用实体—属性—联系的数学模型进行知识表达建立知识库的层次结构,根据支持度确定多维数据关联与分类规则,针对不同专业设定不同的支持度阈值,提高求解最优性,并以多知识库集成模型数据分析为主体,构建一个综合性能分析系统架构模式。仿真分析数据证明,该系统结合数据挖掘与联机数据分析,实现了综合的决策融合,增强了数据的分析能力。通过该系统将舰船设计研发相关的技术、流程、经验和数据等资源进行有效管理,可以有效提升数字化造船水平。 相似文献
896.
Tao Feng Junyi Zhang Akimasa Fujiwara Harry J.P. Timmermans 《Transportation Research Part D: Transport and Environment》2010,15(5):263-274
This paper presents an integrated model system for mobility maximization based on a quantified specification of environmental capacity, and evaluates policy interaction and effectiveness by simulating a number of policy scenarios. The system is designed to specify the maximum level of car ownership and number of trips by private and public modes subject to an environmental capacity constraint defined as the frontier emission under maximum system efficiency. Four types of hypothetical policies (population change, urban sprawl, land-use pattern and network improvement) are designed and the effects of 13 policy scenarios are simulated using data of Dalian City, China. Results reveal that the integrated model system reacts sensitively to policy interventions. The urban sprawl reflected in a changing residential distribution from central to suburban areas is most instrumental from the perspective of pollution alleviation. If the goal is to simultaneously reduce emissions while accommodating mobility, two combinational policy scenarios outperform all others. 相似文献
897.
Panagiotis Ch. Anastasopoulos Raymond J.G.M. Florax Samuel Labi Mathew G. Karlaftis 《Transportation Research Part A: Policy and Practice》2010,44(3):136-146
Highway agencies around the world strive to improve practices for infrastructure maintenance and rehabilitation, using project delivery policies that range from total ‘in-house’ responsibility to complete privatization, with a number of flexible contracting policies such as performance-based contracting, variants of design-build-maintain, and lane rentals among others between these two extremes. In this paper, we present a methodology that duly accounts for underlying spatial effects and estimates the expected cost savings of innovative contracting policies for highway maintenance and rehabilitation relative to in-house execution of these activities. Spatial econometric modeling is used to analyze highway contract data from 49 countries. We also investigate the marginal effects of key explanatory variables on contract cost savings using spatial multipliers. Our findings show that there are significant relationships between cost savings and contract characteristics, and that there is an apparent direct relationship between the average cost savings of contracts in a country and contract average cost savings and contract sizes in neighboring countries. 相似文献
898.
Aklesso Egbendewe-Mondzozo Lindsey M. Higgins W. Douglass Shaw 《Transportation Research Part A: Policy and Practice》2010,44(5):281-290
Red-light cameras placed at intersections have the potential to increase safety, but they are often viewed as an invasion of privacy. Preferences for these cameras were explored using a stated choice model that presents key attributes of camera placements. Stated choice models involve careful experimental design, akin to experimental control in laboratory settings. A variety of design approaches were used, settling on a composition of the choice sets people face in the survey. To illustrate the approach, an internet survey was used with a convenience sample containing a high percentage of college students. The results show that while not the case independently, as the number of cameras and fines for violators are simultaneously increased, the preferences for one particular red light cameras program are likely to improve. 相似文献
899.
Kazuyuki Iwata Toshi H. Arimura 《Transportation Research Part D: Transport and Environment》2009,14(3):157-167
This paper examines the vehicle type regulation that was introduced under the Automobile Nitrogen Oxides–Particulate Matter Law to mitigate air pollution in Japanese metropolitan areas. The vehicle type regulation effectively sets the timing for vehicle retirement by initial registration year and type. However, there was no consideration of cost or efficiency in choosing the timing of retirement. We solve an optimal problem to maximize the social net benefit under the current framework of the vehicle type regulation. The analysis finds that the net benefit can more than double if the optimal retirement timing is chosen. Further, we find that even a simple alteration of the retirement timing can increase the social net benefit by 13%. 相似文献
900.
上中路隧道、军工路隧道作为上海市城市中环线建设中两个重要的穿越黄浦江节点工程,均采用双管双层隧道方案。结合两个工程的设计,介绍了隧道出盾构工作井后两种不同的平面展线形式,同时分析了"燕尾型"展线与"鱼叉型"展线在各个方面的优缺点。 相似文献