共查询到20条相似文献，搜索用时 497 毫秒
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为缓解离港航班延误现状,减少航班延误带来的损失,研究了离港航班优化调度问题.建立了最小化航班延误成本、最小化航班位移量和最小化机位占用时间的多目标优化模型,将遗传算法与滑动时间窗相结合对模型进行求解,仿真结果表明,与先到先服务(FCFS)相比,航班延误损失减少35.5％,且延误损失在各航班之间的分配更加均衡,可见所提优... 相似文献
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文章与Logit模型相结合,提出了一种基于模糊路径选择的模型,让出行者在非饱和的路网结构中,根据各路段行程所需的模糊时间进行路径选择,使整个路网中各路径上用户均衡。该模型也适用于大规模路网中交通流平衡分配,算例结果验证了该模型的有效性和可行性。 相似文献
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Vehicles of different sizes are difficult to navigate in close vicinity. In this paper, we propose multi-vehicle coordination strategy by stochastic control and time scheduling to guarantee no collisions. We use contours and relative motions of vehicles to calculate collision time and use it in multi-vehicle scheduling and reduce computation burden. The proposed strategy enables the vehicles to add calculation delay when vehicles are moving towards the destinations. To avoid complicated control rule design for motion-restricted irregular vehicles, we propose stochastic control to provide satisfactory performance. By changing the frequency of control update, a modification is proposed to take congestion into account. Simulation examples are given to demonstrate the effectiveness of the proposed approach. 相似文献
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研究区域旅游流整体空间网络结构特性及区域内各城市在整体网络中的地位,可为区域旅游的空间布局与优化提供支撑。本文选取长江三角洲30城市重点旅行社推荐的一日游、二日游、三日游（及三日以上）旅游线路共4 500条,运用社会网络理论与方法,从单个城市旅游节点、节点城市间连线、整体空间网络三个方面分析长三角区域旅游流空间网络特征。结果显示：①长三角区内节点城市在区域旅游流空间网络中地位差异较大,核心城市的核心地位较为突出,区域旅游流空间网络存在明显的等级性,随着出游时间的增加,等级性更为明显,如杭州和苏州既是区域内核心的旅游目的地城市,也是重要的旅游中转地,在旅游线路组织方面占有重要地位;②局部旅游流活跃程度较高,如镇江-扬州、舟山-绍兴;③区域旅游流空间网络结构会由于旅游交通条件、大型旅游项目等各种要素的变化而处于动态发展过程中。 相似文献
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文章根据自主设计的一种高速公路汽车防碰撞预警系统,车载装置检测车辆运行状况,判断车辆运行是否异常或有故障,自动或手动发送信息预警,高速公路路边装置接收车载装置的信息,根据信息类型向该车辆行驶方向后面的路边装置发送信息,后面的路边装置将车辆前方的交通异常状况发送给车载装置。文章中构建Zigbee无线网络,设计无线通信协议,规范了车载装置与路边装置,路边装置相互之间,车载装置与入口测试启动装置,出口关闭装置,通信频率设置的通信协议,给出了程序流程图,经过测试满足高速公路汽车防碰撞预警系统的应用要求。 相似文献
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《Journal of The Franklin Institute》2023,360(7):4973-5000
In recent years, regional traffic congestion has become increasingly frequent, which seriously affects the safety and efficiency of urban vehicles. Therefore, traffic flow prediction methods based on artificial intelligence are widely used in traffic management. However, the existing traffic flow prediction methods need to collect raw data, which involves risks of vehicle privacy leakage. Federated learning, which shares model updates without exchanging local data, has gradually become an effective solution to achieve privacy protection. A federated learning traffic flow prediction model for regional transportation systems is proposed in this paper. At the same time, due to the emergence of highly intelligent automatic driving vehicles, a vehicle scheduling system, which can control the departure and routes of vehicles in urban regions is developed in the proposed approach. A road weight measurement method combined with real time traffic information is introduced to optimize the driving routes of vehicles to reduce the average travel time. Additionally, departure strategy, is another factor that has a great influence on traffic efficiency, but is usually ignored in the past, and is also carefully compared and studied in this paper. The numerical results illustrate that the proposed schemes can effectively improve the privacy protection ability of model updates, reduce the scheduling completion time by using the traffic flow prediction model, and realize the comparative research between departure strategies, which provides a reference for developing a safe and efficient regional transportation system. 相似文献
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Recent advances in wireless technologies have led to the development of intelligent, in-vehicle safety applications designed
to share information about the actions of nearby vehicles, potential road hazards, and ultimately predict dangerous scenarios
or imminent collisions. These vehicle safety communication (VSC) technologies rely on the creation of autonomous, self-organizing,
wireless communication networks connecting vehicles with roadside infrastructure and with each other. As the technical standards
and communication protocols for VSC technologies are still being developed, certain ethical implications of these new information
technologies emerge: Coupled with the predicted safety benefits of VSC applications is a potential rise in the ability to
surveil a driver engaging in her everyday activities on the public roads. This paper will explore how the introduction of
VSC technologies might disrupt the “contextual integrity” of personal information flows in the context of highway travel and
threaten one’s “privacy in public.” Since VSC technologies and their related protocols and standards are still in the developmental
stage, the paper will conclude by revealing how close attention to the ethical implications of the remaining design decisions
can inform and guide designers of VSC technologies to create innovate safety applications that increase public safety, but
without compromising the value of one’s privacy in public.
This work was supported by the National Science Foundation PORTIA Grant No. CNS-0331542, and could not have been completed
without the valuable guidance of Prof. Helen Nissenbaum (New York University) and Prof. Dan Boneh (Stanford University). I
am grateful to many other colleagues who generously contributed to this work with excellent comments and suggestions, including
Emily Clark and Steve Tengler at the VSCC, and Sam Howard-Spink, Joseph Reagle and Tim Weber at New York University. Drafts
were further sharpened through opportunities to present at colloquia and conferences sponsored by New York University’s Department
of Culture & Communication, the American Association for the Advancement of Science, the Society for Philosophy and Technology,
and Computer Ethics: Philosophical Enquiry. 相似文献
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本文以乘客出行需求和出行安全为最终目标,研究城市轨道交通在列车延误时,综合考虑线路运输条件、客流分布特点、站点客运组织条件、列车延误时间与地点等各项因素下,采取本线线路或邻线（换乘线路）行车调整（如越站、扣车、加车、变更行车交路等）,提出配套的客流组织措施（客流限流措施、服务补救等）进行综合保障,以提升运输服务水平。 相似文献
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This paper is concerned with event-triggered cooperative control of a platoon of connected vehicles via vehicular ad hoc networks (VANETs). To reduce communications among vehicles, we introduce a hybrid event-triggered transmission mechanism based on both time elapsed and state error. The effect of time-varying transmission delay and communication energy constraint can be also taken into account in the system modeling and design procedures. The on-board sensors use different power levels to transmit information resulting in different packet loss rates. The vehicular platoon system is proved to be exponentially mean-square stable under the hybrid event-triggering scheme and a constant time headway spacing policy. A framework for co-design of the hybrid event triggering scheme and the output feedback controller is given to guarantee platoon stability and spacing-error convergence along the stream. Numerical simulations are given to demonstrate the effectiveness of proposed method. 相似文献
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生态交通系统以人流物流为核心,讲究车、路、站、能源、管理等要素与人、经济、自然的协调,其目标是生态安全、绿色出行、和谐交通。居民以"慢行+公交"生态出行理念的实现,需从规划、技术上扩充步行、自行车与公共交通的生态位,同时采用限行、收费方式压缩轿车的生态位。效仿公交式的物流配送网络建设,既是对轴辐式配送网络的完善,也是货运从独立经营到共同配送的良性生态演化。客运与货运的生态位重叠,可通过时、空维数的部分分离来减缓竞争。 相似文献