共查询到18条相似文献,搜索用时 187 毫秒
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高铁隧道的变形量较小,但受随机噪声的干扰较大,使得监测得到的沉降曲线不能反映实际的沉降情况。鉴于此,文章提出了基于小波变换与卡尔曼滤波相结合的RLG降噪方法,该方法既有小波变换的去相关作用和多分辨分析功能,又有卡尔曼滤波对未知信号的线性无偏最小方差估计的特点。采用GM(1,1)预测模型对降噪后的数据进行分析,得到的结论是:基于小波变换与卡尔曼滤波相结合的GM(1,1)模型的精度较基于卡尔曼滤波的GM(1,1)模型的精度高,可有效地运用于高铁隧道沉降分析中。 相似文献
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靖西天然气管道是重要输气干线,准确预测需求负荷变化情况,确保管道安全、平稳、高效供气意义重大。文中以灰色理论为基础,利用管道历年气量数据建立灰色预测的GM(1,1)模型,采用后验差检验对预测模型进行检验,并对该管道未来用气需求量进行预测。计算结果显示:灰色GM(1,1)模型预测结果与实际结果具有较好的一致性,精度能够满足实际应用的要求,预测结果对靖西管道运行管理具有一定的借鉴作用。 相似文献
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灰色GM(1,1)模型在管道腐蚀预测中的应用 总被引:2,自引:0,他引:2
随着运营时间的增加,输气管道必然受到不同程度的腐蚀,如果不及时维修或更换,一旦发生泄漏引起爆裂,将会造成极大的损失。为了对输气管道的腐蚀程度进行预测,掌握输气管道腐蚀的基本规律,运用GM(1,1)模型对输气管道的腐蚀速度和腐蚀深度的原始数据进行了灰色动态拟合,建立了相应的灰色微分方程和灰色时间响应函数,应用于四川某气田输气管道未来6年的腐蚀情况预测。计算结果表明:建立的管道腐蚀预测模型GM(1,1)模型,与实测数据相比,误差较小,具有一定的实用价值,能为管道运营者采取相应防腐措施提供可靠的依据。 相似文献
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文章基于主成分分析的基本理论与模型,采用SPSS软件,对影响四川省公路客运量的相关因素进行主成分分析,克服多重共线性的问题,构建出四川省公路客运量预测模型。根据预测结果显示,该模型具有较高的精度,适用于影响因素指标较为明确的短期客运量预测,能够满足四川省目前公路客运量预测的需要,对四川地区的公路旅客运输发展也有着一定的指导作用,具有一定的科学性与有效性。 相似文献
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ABSTRACTThe purpose of maritime accident prediction is to reasonably forecast an accident occurring in the future. In determining the level of maritime traffic management safety, it is important to analyze development trends of existing traffic conditions. Common prediction methods for maritime accidents include regression analysis, grey system models (GM) and exponential smoothing. In this study, a brief introduction is provided that discusses the aforementioned prediction models, including the associated methods and characteristics of each analysis, which form the basis for an attempt to apply a residual error correction model designed to optimize the grey system model. Based on the results, in which the model is verified using two different types of maritime accident data (linear smooth type and random-fluctuation type, respectively), the prediction accuracy and the applicability were validated. A discussion is then presented on how to apply the Markov model as a way to optimize the grey system model. This method, which proved to be correct in terms of prediction accuracy and applicability, is explored through empirical analysis. Although the accuracy of the residual error correction model is usually higher than the accuracy of the original GM (1,1), the effect of the Markov correction model is not always superior to the original GM (1,1). In addition, the accuracy of the former model depends on the characteristics of the original data, the status partition and the determination method for the status transition matrix. 相似文献
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This paper describes a logit model of route choice for urban public transport and explains how the archived data from a smart card-based fare payment system can be used for the choice set generation and model estimation. It demonstrates the feasibility and simplicity of applying a trip-chaining method to infer passenger journeys from smart card transactions data. Not only origins and destinations of passenger journeys can be inferred but also the interchanges between the segments of a linked journey can be recognised. The attributes of the corresponding routes, such as in-vehicle travel time, transfer walking time and to get from alighting stop to trip destination, the need to change, and the time headway of the first transportation line, can be determined by the combination of smart card data with other data sources, such as a street map and timetable. The smart card data represent a large volume of revealed preference data that allows travellers' behaviour to be modelled with higher accuracy than by using traditional survey data. A multinomial route choice model is proposed and estimated by the maximum likelihood method, using urban public transport in ?ilina, the Slovak Republic, as a case study 相似文献
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Establishing how to utilize check-in counters at airport passenger terminals efficiently is a major concern facing airport operators and airlines. Inadequate terminal capacity and the inefficient utilization of facilities such as check-in counters are major factors causing congestion and delays at airport passenger terminals. However, such delays and congestion can be reduced by increasing the efficiency of check-in counter operations, based on an understanding of passengers' airport access behaviour. This paper presents an assignment model for check-in counter operations, based on passengers' airport arrival patterns. In setting up the model, passenger surveys are used to determine when passengers arrive at the airport terminals relative to their flight departure times. The model then uses passenger arrival distribution patterns to calculate the most appropriate number of check-in counters and the duration of time that each counter should be operated. This assignment model has been applied at the Seoul Gimpo International Airport in Korea. The model provides not only a practical system for the efficient operations of time-to-time check-in counter assignments, but also a valuable means of developing effective longer-term solutions to the problem of passenger terminal congestion and delays. It also offers airlines a means of operating check-in counters with greater cost effectiveness, thus leading to enhanced customer service. 相似文献
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Daniel A. Badoe 《运输规划与技术》2013,36(5):455-475
Abstract This paper develops alternatively structured trip frequency/generation models, and investigates their forecast performance. The first model presented is the simple linear model with a discussion of its theoretical shortcomings. Models that address, in a progressive fashion, the underlying shortcomings of the linear model are then presented. These models are namely the truncated normal model, the Poisson model, the negative binomial model, and an ordered logit model. The modeling unit employed in the study is the individual. The models are assessed by how closely they are able to replicate trips produced by each individual in the dataset, and by each traffic zone. This assessment of performance in prediction is conducted on an estimation dataset collected in the Toronto Region in 1986, and on an independent dataset collected in the same geographic region, 10 years later, in 1996. The results show that, notwithstanding the simplicity of the simple linear model and its lack of an explicit underlying travel behavioral theory, it predicts travel in the base and forecast years with less error compared to any of the more complex models. 相似文献
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This paper presents a discussion on the relationship between organizational forms (including the ownership structure and the contractual practices) and passenger satisfaction of Chinese public transport service. To test this proposition, an original rich data set covering 4702 respondents and 58 public transport operators of 13 cities for the period 2013–2014 is used. We firstly estimate the passenger satisfaction based on customer satisfaction theory and PLS-SEM, and then take into consideration the mixed logit model to assess the effect between them. Conclusions drawn from the study are summarized as follows: ① The effect of organizational forms on the passenger satisfaction of public transport service is confirmed. ② Public transport services franchised to public ownership offer higher passenger satisfaction than those franchised to private ownership and mixed ownership. ③ Public transport services regulated by the management contracts incite more passenger satisfaction than those regulated by net cost contracts and gross cost contracts. 相似文献
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This study employs back-propagation neural networks (BPN) to improve the forecasting accuracy of air passenger and air cargo demand from Japan to Taiwan. The factors which influence air passenger and air cargo demand are identified, evaluated and analysed in detail. The results reveal that some factors influence both passenger and cargo demand, and the others only one of them. The forecasting accuracy of air passenger and air cargo demand has been improved efficiently by the proposed procedure to evaluate input variables. The established model improves dramatically the forecasting accuracy of air passenger demand with an extremely low mean absolute percentage error (MAPE) of 0.34% and 7.74% for air cargo demand. 相似文献