排序方式: 共有91条查询结果,搜索用时 15 毫秒
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从人车路相互作用出发,建立了人车路系统振动方程和路桥过渡段路面不平整模型,并通过编制的RCBP程序分析了车辆行驶舒适性的影响因素,最后确定了基于行驶舒适性的路桥过渡段差异沉降控制标准。结果不仅可以用于路桥过渡段差异沉降控制标准的相关规范,也可用于一般路基差异沉降标准的制定,对桥头跳车问题的处治和路桥过渡段路面的养护维修提供了科学决策依据。 相似文献
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介绍了一种同时利用多组实际运行参数反算管内壁粗糙度的新方法——最小二乘法,该方法可以有效减少生产报表上运行参数记录值的随机偏差所导致的反算结果偏差。编制了该方法的计算机软件,并利用它计算了国内某干线输气管道的当量粗糙度,计算结果表明其各管段的当量粗糙度为0.017~0.043mm之间。 相似文献
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Zulema D. Garraffo Arthur J. Mariano Annalisa Griffa Carmela Veneziani Eric P. Chassignet 《Journal of Marine Systems》2001,29(1-4)
A model/data comparison was performed between simulated drifters from a high-resolution numerical simulation of the North Atlantic and a data set from in situ surface drifters. The comparison makes use of pseudo-Eulerian statistics such as mean velocity and eddy kinetic energy, and Lagrangian statistics such as integral time scales. The space and time distribution of the two data sets differ in the sense that the in situ drifters were released inhomogeneously in space and time while the simulated drifters were homogeneously seeded at the same time over a regular 1° grid. Despite this difference, the total data distributions computed over the complete data sets show some similarities that are mostly related to the large-scale pattern of Ekman divergence/convergence.Comparisons of eddy kinetic energy and root mean square velocity indicate that the numerical model underestimates the eddy kinetic energy in the Gulf Stream extension and in the ocean interior. In addition, the model Lagrangian time scales are longer in the interior than the in situ time scales by approximately a factor of 2. It is suggested that this is primarily due to the lack of high-frequency winds in the model forcing, which causes an underestimation of the directly forced eddy variability. Regarding the mean flow, the comparison has been performed both qualitatively and quantitatively using James' statistical test. The results indicate that over most of the domain, the differences between model and in situ estimates are not significant. However, some areas of significant differences exist, close to high-energy regions, notably around the Gulf Stream path, which in the model lies slightly north of the observed path, although its strength and structure are well represented overall. Mean currents close to the buffer zones, primarily the Azores Current, also exhibit significant differences between model results and in situ estimates. Possibilities for model improvement are discussed in terms of forcings, buffer zone implementations, turbulence and mixed layer parameterizations, in light of our model/data comparison. 相似文献
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提出了软土路基设计为过程化设计的概念,在此基础,采用最小二乘拟合数学方法,建立软土路基沉降变化趋势面实用模型的过程和方法,并给出实例,为进一步运用时间序列分析方法定量研究沉降趋势,实现工后沉降量的精确预测和控制模型的建立,以及在计算机上实现三维量化分析奠定基础。 相似文献
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中西文化之伦理比较--以儒家中庸观与古希腊中道观为视角 总被引:2,自引:0,他引:2
杨漪晴 《上海交通大学学报(哲学社会科学版)》2004,12(3):45-47,59
由于不同的地理环境,社会和经济结构,中西文化从人类历史的最初就表现出极大的差异。这点在儒家中庸观和古希腊的中道观上也得到体现。建立在“天人合一”基础上的中庸之道强调个人对于群体及周围环境的道德责任感,并认为只有通过不断的修身,完善个人内在品质才能达到最终的“德性”。而古希腊以亚里斯多德为代表的哲学家们则把人从自然中分离出来,并重视个人意志自由。他指出“中道”可以通过后天的实践获得,而规章法律就是这种“德性”的象征。尽管两者在起源,思想内涵,和实现途径有着明显不同,中庸之道和中道观都反映了一种辩证思维,并以寻求社会安定为服务目的. 相似文献
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GPS已经广泛应用于交通领域。本文探讨了利用GPS车辆定位信息,进行路段旅行时间和路段平均速度估计的相关算法。重点讨论了在GPS返回数据的不同情况下,进行旅行时间的推算,以及平均速度的估计。通过路上试验,说明该算法能够得到路段合理的旅行时间和平均速度,能够描述路网的运行状态。 相似文献
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基于贝叶斯置信框架的最小二乘支持向量机模型参数选择方法及SS_7型电力机车牵引电机建模 总被引:1,自引:0,他引:1
利用贝叶斯置信框架推断LS-SVM模型参数并建立贝叶斯LS-SVM曲线拟合模型.运用贝叶斯LS-SVM曲线拟合模型对SS_7型电力机车牵引电机的磁化曲线进行拟合.结果表明:贝叶斯LS-SVM曲线拟合模型对SS_7型电力机车牵引电机的磁化曲线拟合速度及精度均有较大地提高,小样本条件下的泛化能力更好.依据贝叶斯LS-SVM曲线拟合模型建立了SS_7型电力机车牵引电机的仿真模型.仿真计算表明,所建的SS_7型电力机车牵引电机仿真模型与机车牵引电机实际运行状况吻合,可用于对SS_7型电力机车主电路性能及控制策略的研究. 相似文献