二维黄金分割法在抗滑桩截面优化设计中的应用   总被引：1，自引：0，他引：1  

李长冬  胡新丽  汤旻烨  董治军 《地质科技情报》2007,26(5):91-94

在对抗滑桩截面宽度和截面高度与抗滑桩费用之间的关系进行综合讨论分析的基础上,引入二维黄金分割法与计算机编程方法,编制了专门的计算软件对抗滑桩截面进行优化设计,以实现满足抗滑要求的前提下使单抗滑桩工程总费用达到最低的优化目的.在三峡库区某工程的实例应用表明,该方法具有良好的社会经济效益,对滑坡的治理设计具有较重要的实际应用价值.  相似文献   

Preconditioned IDR(s) iterative solver for non‐symmetric linear system associated with FEM analysis of shallow foundation     

H.H.T. Tran  K.C. Toh  K.K. Phoon 《国际地质力学数值与分析法杂志》2013,37(17):2972-2986

Non‐associated flow rule is essential when the popular Mohr–Coulomb model is used to model nonlinear behavior of soil. The global tangent stiffness matrix in nonlinear finite element analysis becomes non‐symmetric when this non‐associated flow rule is applied. Efficient solution of this large‐scale non‐symmetric linear system is of practical importance. The standard Krylov solver for a non‐symmetric solver is Bi‐CGSTAB. The Induced Dimension Reduction [IDR(s)] solver was proposed in the scientific computing literature relatively recently. Numerical studies of a drained strip footing problem on homogenous soil layer show that IDR(s = 6) is more efficient than Bi‐CGSTAB when the preconditioner is the incomplete factorization with zero fill‐in of global stiffness matrix K_ep (ILU(0)‐K_ep). Iteration time is reduced by 40% by using IDR(s = 6) with ILU(0)‐K_ep. To further reduce computational cost, the global stiffness matrix K_ep is divided into two parts. The first part is the linear elastic stiffness matrix K_e, which is formed only once at the beginning of solution step. The second part is a low‐rank matrix Δ, which is re‐formed at each Newton–Raphson iteration. Numerical studies show that IDR(s = 6) with this ILU(0)‐K_e preconditioner is more time effective than IDR(s = 6) with ILU(0)‐K_ep when the percentage of yielded Gauss points in the mesh is less than 15%. The total computation time is reduced by 60% when all the recommended optimizing methods are used. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

CP准晶结构模型的Hausdorff维数计算     

陈敬中  杜伯仁 《地球科学》1989,14(3):253-258

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中条山地区早前寒武纪岩石 含铀矿化岩石稀土元素与铀的关系及其意义     

李子颖 《铀矿地质》1989,(5)

本文研究了中条山地区基底涑水杂岩,含矿层中条群岩石和铀矿化岩石的稀土元素特征及其与铀元素的关系。发现稀土元素,尤其是重稀土元素对铀的区域富集及铀矿化作用有一定的指示意义。  相似文献   

用相关系数估计导线点误差椭圆参数     

张兰英 《华东地质学院学报》1988,(3)

用比例误差k和导线边数n所表示的坐标相关系数r,当导线走向α=45°时,误差椭圆大小、形状与相关系数之间存在一个简单的数学关系式,在导线设计时可用作精度估算。  相似文献   

Dimension and entropy in the soil-covered landscape   总被引：2，自引：0，他引：2  

W. E. H. Culling 《地球表面变化过程与地形》1988,13(7):619-648

Both the Hausdorff dimension and the K-entropy supply a measure of the irregularity of the landspace surface. The relationship between the two measures is investigated over a variety of terrains in Britain and a method of calculating the entropy is checked against an independent estimate of the dimension with reasonable agreement. The calculation of the K-entropy requires that the landscape surface be represented by an homogenous ergodic random field. This condition is satisfied by the tendency of soil-covered terrains to progressively approximate to a form well represented by a Gaussian field. Gaussian random fields can either be very smooth, possessing derivatives of all orders at every point or they are highly irregular and non-differentiable everywhere. Within the regular conceptualization the Rice-Kac theory is used to predict the numbers of crossing points and the extent of excursion sets. These predictions are tested against an example terrain from the High Weald of East Sussex with very good agreement, apart from predictions of local maxima. A worked example of the calculation of the K-entropy is given as an appendix. The potential role of information theory in geomorphology extends beyond the use made of entropy in this investigation. In particular ergodic theory has important practical and theoretical implications.  相似文献   

略论水资源系统的混合模型   总被引：1，自引：0，他引：1       下载免费PDF全文

郭元裕  沈佩君 《水科学进展》1993,4(2):147-152

大系统优化的关键在于模型的降维.混合模型可看作为一种降维方法,它通过把整个系统分解为联系比较松散的几个子系统,达到降维目的.从理论上对这类模型的建模原则、优化技术及其分类和特点进行了归纳和总结,说明了在多目标复杂水资源系统和排灌系统中这种混合模型的应用是十分有效的.  相似文献   

月降水量的持续性分析   总被引：1，自引：0，他引：1  

陈兴芳  宋文玲 《应用气象学报》1993,(Z1)

根据1951—1990年全国160站月降水量资料,通过计算相关系数、相关概率和持续性比,统计分析降水量的月际持续性特点.其结果可为月尺度降水的长期预报提供有关信息和相应的气候概况.  相似文献   

Application of objective analysis to metallic traces in the atmospheric aerosol     

Christophe Migon  Bernard Gentili 《Journal of Atmospheric Chemistry》1993,16(3):277-284

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赤道东太平洋海温与长江下游地区降水异常的相关分析   总被引：18，自引：0，他引：18       下载免费PDF全文

费亮  王玉清  薛宗元  吴天泉 《气象学报》1993,51(4):442-447

本文采用最大熵谱分析方法揭示了赤道东太平洋海温和长江下游地区降水均存在3-4年和准两年的周期性振荡特征。且通过时滞相关分析发现两者均存在显著的相关关系,并以降水滞后海温约4个月的正相关最为明显。在此基础上利用一个多级数字滤波器对两者的逐月距平序列进行了高通、低通和带通滤波,并对两者在不同时间尺度上的滤波分量进行时滞相关分析,结果发现只是在2-4年的时间尺度上两者相关最为密切,并以降水滞后海温4-5月的正相关最为显著。  相似文献