岩体抗剪强度参数的线性优化方法     

李倩倩  黄栋  乔建平  崔中兴 《岩土力学》2014,35(Z2):156-161

针对岩体结构面力学参数的重要性,以大量工程实例为依据,以统计误差分析相关理论为基础,研究最小二乘法与M-估计法在分析结构面抗剪强度参数时的适用性。研究结果表明,在难以判断粗差的数量和比例时,很难对两种线性回归方法的优劣进行规律性的比较。考虑到数据是具有工程特性的,为更准确地处理实验数据,在以上两种方法的基础上提出了一种新的实验数据处理方法,并应用于计算李家河水库的抗剪强度参数。  相似文献   

泉州地区地下水位观测资料初步分析     

尤宇星  陈小云  谢文杰  林文峰  吴声伟  黄圣棕 《华北地震科学》2014,(1):65-72

介绍了泉州地区地下流体网点分布的概况,对水位观测资料质量进行简单地分析。着重探讨水位观测资料的连续完整率、稳定性、动态特征及其观测资料的内在观测质量等,以获取泉州地区水位观测资料对于地震预报的利用价值。  相似文献   

Recent progress of seismic research on tall buildings in China Mainland     

Qian Jiaru  Li Ningbo  Ji Xiaodong  Zhao Zuozhou 《地震工程与工程振动(英文版)》2014,13(1):47-57

To study the seismic behavior of high strength concrete fi lled double-tube(CFDT) columns,each consisting of an external square steel tube and an internal circular steel tube,quasi-static tests on eight CFDT column specimens were conducted.The test variables included the width-to-thickness ratio(β1) and the area ratio(β2) of the square steel tube,the wall thickness of the circular steel tube,and the axial force(or the axial force ratio) applied to the CFDT columns.The test results indicate that for CFDT columns with a square steel tube with β1 of 50.1 and 24.5,local buckling of the specimen was found at a drift ratio of 1/150 and 1/50,respectively.The lateral force-displacement hysteretic loops of all specimens were plump and stable.Reducing the width-to-thickness ratio of the square steel tube,increasing its area ratio,or increasing the wall thickness of the internal circular steel tube,led to an increased fl exural strength and deformation capacity of the specimens.Increasing the design value of the axial force ratio from 0.8 to 1.0 may increase the fl exural strength of the specimens,while it may also decrease the ultimate deformation capacity of the specimen with β1 of 50.1.  相似文献   

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王解先  冯宝新 《大地测量与地球动力学》2010,30(1):74-76

??С?????????????????????Σ??÷?????????????????????档????????????????????Jacobi????????????????????任???????????????????????????????????????????????????÷??????????????????ж????????????????????????????????????????????????????  相似文献   

信号与噪声权选择对GPS高程拟合精度的影响     

魏玉明  张永志  王帅 《大地测量与地球动力学》2016,36(3):226-228

阐述了最小二乘配置基本原理,给出在吉洪诺夫条件下的最小二乘解和一种新的确定经验协方差的方法,并通过实例讨论信号与噪声权的选择对GPS高程拟合精度的影响。结果表明,随着信号与噪声权比的增大,内符合精度明显提高,检核精度也有一定的提高。  相似文献   

Potential of support vector regression for prediction of monthly streamflow using endogenous property   总被引：2，自引：0，他引：2  

Rajib Maity  Parag P. Bhagwat  Ashish Bhatnagar 《水文研究》2010,24(7):917-923

In the recent past, a variety of statistical and other modelling approaches have been developed to capture the properties of hydrological time series for their reliable prediction. However, the extent of complexity hinders the applicability of such traditional models in many cases. Kernel‐based machine learning approaches have been found to be more popular due to their inherent advantages over traditional modelling techniques including artificial neural networks(ANNs ). In this paper, a kernel‐based learning approach is investigated for its suitability to capture the monthly variation of streamflow time series. Its performance is compared with that of the traditional approaches. Support vector machines (SVMs) are one such kernel‐based algorithm that has given promising results in hydrology and associated areas. In this paper, the application of SVMs to regression problems, known as support vector regression (SVR), is presented to predict the monthly streamflow of the Mahanadi River in the state of Orissa, India. The results obtained are compared against the results derived from the traditional Box–Jenkins approach. While the correlation coefficient between the observed and predicted streamflows was found to be 0·77 in case of SVR, the same for different auto‐regressive integrated moving average (ARIMA) models ranges between 0·67 and 0·69. The superiority of SVR as compared to traditional Box‐Jenkins approach is also explained through the feature space representation. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

用等厚薄层权重自适应迭代阻尼最小二乘法反演瑞雷波频散曲线   总被引：7，自引：1，他引：6  

宋先海  肖柏勋  黄荣荣  顾汉明  张学强 《物探与化探》2003,27(3):212-216

笔者在前人工作基础上提出的等厚薄层权重自适应迭代阻尼最小二乘法,能有效地解除对初始模型的依赖.理论模型与实际资料试算结果表明,用该算法对瑞雷波频散曲线进行反演,具有稳定性好、精度高、分辨能力强的特点,并能自动分层和反演地层参数.  相似文献   

On Methods for the Light Curves Extrema Determination     

Zdeněk Mikulášek  Marek Wolf  Miloslav Zejda  Petra Pecharová 《Astrophysics and Space Science》2006,304(1-4):363-365

We present two methods for the determination of moments of extrema and their errors appropriate for the analysis of light variations of variable objects. The method I is suitable for determination of times of extrema of non-periodical variables or objects, whose light curves vary. The method II is apt for O-C analyses of objects whose light curves are more or less repeating. Both methods are displayed on the analysis of BL Cam light variations and compared with the Kwee-van Woerden method.  相似文献   

观测室温度对新沂台地电阻率内在质量的影响研究     

李飞  孙雷  夏忠 《地震地磁观测与研究》2005,26(1):100-105

自2001年底以来，在冬季室温过低时，地电阻率随着时间的推移其内在质量越来越低。2004年1月底到2月初，通过对仪器进行升温是否会对地电阻率产生影响，以及进行观测室不同温度下对地电阻率观测数据的对比分析。揭示出观测室温度是影响新沂台地电阻率内在质量的重要原因，对今后提高新沂台地电阻率观测数据的内在质量有一定意义。  相似文献   

最小二乘曲线拟合在变形监测中的应用   总被引：3，自引：0，他引：3  

王义峰  刘立龙  文鸿雁 《地理空间信息》2007,5(3):109-110

对变形测量数据进行分析,运用最小二乘曲线拟合的方法,得到了拟合多项式和拟合曲线,并评定了精度。最小二乘法是带有测量数据误差的曲线拟合中一种有效的方法。  相似文献