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21.
MGM(1,n)模型在软土路基沉降预测中的应用 总被引:2,自引:2,他引:2
为提高高等级公路路基沉降预测的准确性,提出了一种由灰色相似关联度分析优选各个相关预测变量,构建灰色MGM(1,n)模型进行沉降预测的方法,可以更全面有效地利用工程监测数据.实例分析对比表明,这种方法比其他常用沉降预测法具有更高的准确性和可靠性. 相似文献
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This paper systematically reviews studies that forecast short-term traffic conditions using spatial dependence between links. We extract and synthesise 130 research papers, considering two perspectives: (1) methodological framework and (2) methods for capturing spatial information. Spatial information boosts the accuracy of prediction, particularly in congested traffic regimes and for longer horizons. Machine learning methods, which have attracted more attention in recent years, outperform the naïve statistical methods such as historical average and exponential smoothing. However, there is no guarantee of superiority when machine learning methods are compared with advanced statistical methods such as spatiotemporal autoregressive integrated moving average. As for the spatial dependency detection, a large gulf exists between the realistic spatial dependence of traffic links on a real network and the studied networks as follows: (1) studies capture spatial dependency of either adjacent or distant upstream and downstream links with the study link, (2) the spatially relevant links are selected either by prejudgment or by correlation-coefficient analysis, and (3) studies develop forecasting methods in a corridor test sample, where all links are connected sequentially together, assume a similarity between the behaviour of both parallel and adjacent links, and overlook the competitive nature of traffic links. 相似文献
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白丽 《交通运输系统工程与信息》2017,17(1):127-135
城市轨道交通客流特征除表现为常态的周期性、季节性及高峰性外,还会因节假日、体育赛事、城市大型活动、突发事件、特殊天气等因素表现出差异性和特殊性,本文对较为成熟的常态及研究较少的非常态客流预测方法进行了实验.首先利用通用的ARIMA时间序列预测算法分析样本历史数据实现常态日客流预测;其次针对客流特殊因素提出时间序列及回归分析的组合模型,同时引进虚拟变量和结合相似日样本数据进一步改进,实现非常态预测问题的高精度求解.仿真计算结果表明,本文方法对解决短期客流预测具有良好的适用度,尤其同样本同预测周期条件下的非常态组合改进模型和常用单一时间序列模型的对比,证明改进模型可以很好地应用在客流特征既包括随时间固有不变的性质又表现出特殊因素的研究中,具有较强的自适应性和更好的预测精度. 相似文献
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ABSTRACTThis paper describes the development of railway station choice models suitable for defining probabilistic station catchments. These catchments can then be incorporated into the aggregate demand models typically used to forecast demand for new rail stations. Revealed preference passenger survey data obtained from the Welsh and Scottish Governments was used for model calibration. Techniques were developed to identify trip origins and destinations from incomplete address information and to automatically validate reported trips. A bespoke trip planner was used to derive mode-specific station access variables and train leg measures. The results from a number of multinomial logit and random parameter (mixed) logit models are presented and their predictive performance assessed. The models were found to have substantially superior predictive accuracy compared to the base model (which assumes the nearest station has a probability of one), indicating that their incorporation into passenger demand forecasting methods has the potential to significantly improve model predictive performance. 相似文献
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Within the literature concerned with aspects of competitiveness, innovation and strategic management of industrial clusters, the body regarding forecasting of strategic management is still nascent. This work aspires to render a contribution within the domain of strategic management forecasting, through the indicative case of European maritime clusters. For this end, a two-tier model is formulated. A quantitative strengths, weaknesses, opportunities, and threats (SWOT) methodology that derives from the fusion of a quondam situation analysis and crosstabs’ theory is generated. This leads to the utilization of the crosstab’s conditional probabilities as transition probabilities; the latter are called to compile the transition matrix of a Markov chain. Through this methodology, and the successive Markov chain’s transition matrices, strategic forecasts are extracted for a devised European maritime cluster case. This work relinquishes a novel application with respect to strategic management forecasting, that provides a dichotomy of practical interpretations and scenarios for quantitative situation analysis. Thus, it may enable effective real-time decision-making for strategic management and/or policy drafting. The situation analysis forecasting model may find applicability in a plethora of practical and theoretical cases, wherein forecasting may be desirable. It may as well pertain to an intrinsic methodology for situation analysis forecasting of maritime clusters. 相似文献
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为进一步保障浮式生产储油装置(FPSO)的作业安全,通过海洋环境条件测量、FPSO运动和单点系泊系统(SPM)状态监测以及理论计算等手段,实现了软刚臂单点系泊监测预报系统的方案设计,并成功应用于渤海油田。经现场应用验证,该系统能够实现对FPSO及SPM运行情况的监测,为作业者提供FPSO操作指导及预警,有效的降低了作业风险。 相似文献
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