共查询到17条相似文献,搜索用时 46 毫秒
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利用数据包络分析(DEA)方法进行效率计算时,若有新增参评样本则下阶段计算时旧样本的效率计算结果可能会随之改变,针对此问题,引入反向传播神经网络(BPNN),基于含偏好序的DEA-CCR模型效率计算结果进行训练,构建DEA-BPNN效率计算模型,在不影响旧样本阶段计算结果的前提上计算新增样本效率。以杭深线厦深段高速列车运行图为例,根据运行线技术指标,利用DEA-BPNN高速列车运行线效率计算模型对2021年第1季度和第2季度厦深段运行图的本线高速列车进行效率计算,研究结果表明,第1季度厦深段本线列车平均效率为0.946,而第2季度本线列车平均效率达到了1.048,说明2021年第2季度厦深达速调图后运行线效率相较上一季度有较大提升。 相似文献
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本文从列车速度、服务水平、鲁棒性、弹性及列车运行水平5个方面,构建列车运行图质量评价指标体系,通过AHP计算各指标权重,构建广义模糊软集模型确定列车运行图综合得分系数,实现列车运行图编制质量评估。为了对算法效果进行验证,以徐盐、连淮铁路网络中京沪高铁南京南至徐州东段、徐兰高铁徐州东至商丘郑徐场段、青盐铁路青岛北至连云港段三条线路为例进行运行图质量评价。结果表明,京沪高铁南京南至徐州东段的运行图综合质量最好,青盐铁路青岛北至连云港段运行图综合质量最差。 相似文献
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为保证列车折返接续过程鲁棒性较高、提高线路通过能力,针对具备开行快慢车条件的城市轨道交通线路,在传统列车运行图编制的基础上同时排列列车折返进路,建立混合整数非线性规划模型,输出具体体现折返进路的列车运行图。借助遗传算法对小规模算例进行求解验证,以期为相关工作提供参考。 相似文献
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随着我国高速铁路的建设,高速铁路逐渐成为人们出行的主流交通方式之一。高速列车停站方案在很大程度上反映了高速铁路的服务水平和铁路运输能力的配置,为了满足旅客的出行需求,对高速列车停站方案进行研究和优化具有重要意义。本文在列车停站方案定义和可达性涵义的基础上提出了高速列车停站方案可达性的涵义,将停站方案可达分为直达可达和换乘可达并分别给出度量指标和计算方法,建立以旅客直达可达性和换乘可达性综合最优为优化目标的高速列车停站方案优化模型,并以京沪高铁"北京南—上海虹桥"区段列车的停站方案为实例,利用模拟退化算法对其进行优化。 相似文献
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从以可靠性为中心的维修管理理论体系(简称RCM)出发,对上海地铁列车可用率进行优化。首先找出影响列车可用率的主要因素,从而改变各系统维修策略来提高列车可用率,达到提高用户满意度的目的。 相似文献
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为了探讨超声波成像技术在铁路列车车轴缺陷检测方面的应用,提高检测的准确性和效率,分析超声波检测技术,对超声波成像技术在列车车轴缺陷检测领域的应用进行阐述,并提出一种基于卷积自编码器的自动检测模型。试验结果证明,超声波检测技术在铁路列车车轴缺陷检测中具有巨大潜力,能够显著提高检测的准确性和效率,进一步提升铁路运输的安全性和可靠性。 相似文献
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管道应力分析主要包括3方面内容:正确建立模型、真实地描述边界条件、正确地分析计算结果。所谓建立模型就是将所分析管系的力学模型按一定形式离散化,简化为程序所要求的数学模型,模型的真实与否是做好应力分析的前提条件。 相似文献
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管道应力分析主要包括3方面内容:正确建立模型、真实地描述边界条件、正确地分析计算结果。所谓建立模型就是将所分析管系的力学模型按一定形式离散化,简化为程序所要求的数学模型,模型的真实与否是做好应力分析的前提条件。 相似文献
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This paper analyzes the observed decision-making behavior of a sample of individuals impacted by Hurricane Irma in 2017 (n = 645) by applying advanced methods based in discrete choice theory. Our first contribution is identifying population segments with distinct behavior by constructing a latent class choice model for the choice whether to evacuate or not. We find two latent segments distinguished by demographics and risk perception that tend to be either evacuation-keen or evacuation-reluctant and respond differently to mandatory evacuation orders.Evacuees subsequently face a multi-dimensional choice composed of concurrent decisions of their departure day, departure time of day, destination, shelter type, transportation mode, and route. While these concurrent decisions are often analyzed in isolation, our second contribution is the development of a portfolio choice model (PCM), which captures decision-dimensional dependency (if present) without requiring choices to be correlated or sequential. A PCM reframes the choice set as a bundle of concurrent decision dimensions, allowing for flexible and simple parameter estimation. Estimated models reveal subtle yet intuitive relations, creating new policy implications based on dimensional variables, secondary interactions, demographics, and risk-perception variables. For example, we find joint preferences for early-nighttime evacuations (i.e., evacuations more than three days before landfall and between 6:00 pm and 5:59 am) and early-highway evacuations (i.e., evacuations more than three days before landfall and on a route composed of at least 50% highways). These results indicate that transportation agencies should have the capabilities and resources to manage significant nighttime traffic along highways well before hurricane landfall. 相似文献
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Abstract Estimating missing values is known as data imputation. Previous research has shown that genetic algorithms (GAs) designed locally weighted regression (LWR) and time delay neural network (TDNN) models can generate more accurate hourly volume imputations for a period of 12 successive hours than traditional methods used by highway agencies. It would be interesting and important to further refine the models for imputing larger missing intervals. Therefore, a large number of genetically designed LWR and TDNN models are developed in this study and used to impute up to a week-long missing interval (168 hours) for sample traffic counts obtained from various groups of roads in Alberta, Canada. It is found that road type and functional class have considerable influences on reliable imputations. The reliable imputation durations range from 4–5 days for traffic counts with most unstable patterns to over 10 days for those with most stable patterns. The study results clearly show that calibrated GA-designed models can provide reliable imputations for missing data with ‘block patterns’, and demonstrate their further potentials in traffic data programs. 相似文献
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文章结合湖南雪峰山隧道工程,讨论了通风网络理论及其在公路隧道中的应用,通过推导交通通风力的计算公式,介绍了通风网络中风机、自然风等各压力源的处理办法。 相似文献