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2020年初爆发新冠肺炎疫情,民航运输业受到了巨大的冲击,虽后续国内疫情得到了一定程度的控制,但国外疫情的泛滥,以至于2021年国内各地疫情的点状爆发,对民航客运生产仍持续造成不同程度的影响。鉴于民航客运生产与市场环境紧密相关,且根据国家卫健委的预判,疫情在今后较长一段时间内将长期存在。为了让民航客运生产运营单位在未来能够科学地评价有疫情存在的特殊市场需求,以及合理地规划和安排航班生产,本文提出一种遗传优化算法(GA)结合反向传播神经网络(BPN)的预测模型。实例应用的结果表明,GA-BPN模型相比传统BPN模型降低具备更高的预测精度,可为未来民航的生产规划提供一定程度科学地指导。 相似文献
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2019年12月份爆发的新型冠状病毒肺炎疫情蔓延全国。疫情期间,全国范围交通管控导致交通状态明显有别于正常状态。为此,本文从公路、铁路、水路、民航、城市交通等多种交通方式出发选取客运指标,利用合成指数方法构建人员流动指数。在省级层面构建省际人员流动指数和省内人员流动指数,分析疫情期间省际和省内人员流动指数特征,以及公路、铁路、水路、民航、城市交通等各项子指标的变化特征,旨在准确监控疫情期间客运交通状态,准确掌握各种交通方式受疫情影响程度,为特殊时期管理部门对旅客运输采取针对性管控提供依据。 相似文献
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我国客运需求增长与结构演变的发展趋势 总被引:1,自引:1,他引:0
未来十年,客运需求逐渐趋向多元化、快速化和个性化,主要表现为,铁路市场份额将稳中有升,民航市场份额将稳步上升;消费性客运需求、快速客运方式的市场需求、城市群地区的客运需求、私人交通需求在客运总需求中的比重呈现不断提高的趋势。 相似文献
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航空安全信息的统计分析可以为航班的风险控制与安全预警提供有效支持。本文在收集整理印尼2007—2017年民航事件信息,基于事件触发机制的思想对其产生原因进行研究分析,运用统计分析法总结印尼民航不安全事件发生的主要原因及类型,同时采用K-means聚类分析法对飞行事故的风险等级进行评估,以发生次数和受伤人数作为观测集,得出跑道外接地的事故风险等级为高,冲出跑道的事故风险等级为中。在此分析基础上,提出相关的改进建议,并对我国处在特殊地理位置和气候条件的机场提供改进的角度和思路,对于同类型不安全事件频发的航空公司起到警示和预防作用。 相似文献
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Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD). An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip. It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links. 相似文献
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本文阐述了混合动力列车的技术特点及其相应优势与劣势,同时介绍了其在国内外的研究动向,并对其应用前景进行了展望。尽管该类新型铁道车辆的续航能力、电池寿命以及成本等相关问题目前仍有待改善,但以其对城市环境的美化作用与优越的舒适驾乘性能,以及高效节能、绿色环保的显著优势,依然不失为一类充满前景的新型轨道交通运输方式。 相似文献
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This paper estimates the efficiencies and productivity changes of 12 international airports in the Asia-Pacific region based on data from 1998 to 2006. We apply stochastic frontier analysis (SFA) to compute efficiency estimates and use the Malmquist productivity index (MPI) to analyze productivity changes. We use the SFA model with a translog-type production function after testing the statistical hypotheses. According to the results of the SFA hypothesis tests, airports have experienced a technological regression; the deviations from the efficiency frontier are caused more by technical inefficiency than random noise. However, the inefficiency was found to decrease. The MPI reveals a declining trend resulting more from technological change than from efficiency change, with a decrease in inefficiency. Taken together, both the hypothesis tests and the MPI not only provide consistent conclusions, but also suggest that airports should concentrate on technological progress. 相似文献
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In India pedestrians usually cross the road at mid-block crosswalks due to ease of access to their destination or the development of adjacent land use types such as shopping, business areas, school and residential areas. The behaviour of pedestrian will change with respect to different land use type and this change in behaviour of pedestrian further reflects change in perceived level of service (LOS). So, it is important to evaluate the quality of service of such crossing facilities with respect to different land-use type under mixed traffic conditions. In this framework, pedestrian perceived LOS were collected with respect to different land-use type such as shopping, residential and business areas. The ordered probit (OP) model was developed by using NLOGIT software package, with number of vehicles encountered, road crossing difficulty as well as safety considered as primary factors along with pedestrian individual factors (gender and age), land-use type and roadway geometry. From the model results, it has been concluded that perceived safety, crossing difficulty, land-use condition, number of vehicles encountered, median width and number of lanes have significant effect on pedestrian perceived LOS at unprotected (un-signalized) mid-block crosswalks in mixed traffic scenario. The inferences of these results highlights the importance of land use planning in designing a new set of pedestrian access facilities for unprotected mid-block crosswalks under mixed traffic conditions. Also the study results would be useful for evaluating pedestrian accessibility taking into account different land-use type and planning required degree of segregation with vehicular movement at unprotected mid-block crosswalk locations. 相似文献
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管道风险分析指数评分法中重要步骤之一就是确定影响管道事故因素的权重,各个管道风险因素在整个管道事故中所占的权重是不相同的。针对目前管道风险分析指数评分法基本假设之一(各因素的分值范围都是0~100分),为了更加客观、准确、合理地反映各个风险因素对于管道事故的影响程度,提出并论述了依据层次分析法的数学逻辑性进行综合计算得出管道风险因素的权重,然后对评分法中各个因素的最高分值,根据其权重不同进行相应调整,从而增强评价者对风险因素的认识和评判能力,提高管道风险评价结果的准确性。 相似文献