共查询到18条相似文献，搜索用时 359 毫秒
1.
Tisseur(2000)研究了非齐次多项式特征值问题的条件数，所得结果的不足是对无穷特征值必须另外处理；Declieu和Tisseur(2003)运用微分几何方法研究了齐次多项式特征值问题的条件数，所得结果的不足之处是与系数矩阵的尺度化(scaling)有关。这两种条件数都有各自的应用范围。本文基于投影尺度引入齐次多项式特征值问题的条件数，其优点是与系数矩阵的尺度化无关，因而也许会有较广泛的应用。 相似文献
2.
本文用有限元素法求解近海水域谐波响应的特征值问题。这是一个广义特征值问题,文中引入固体力学中聚缩质量矩阵的概念和方法,对问题进行简化,计算了两个算例,同理论值及实验值相比较,结果良好. 相似文献
3.
本文研究一类反对称特征值问题在实扰动情形下的向后误差。该问题的系数矩阵同时具有反对称性和零块结构。本文将给出范数型双结构向后误差的表达式,并将所得结果与一般的反对称结构向后误差进行比较。数值实验结果表明,双结构向后误差和反对称结构向后误差的比值有时会非常大。 相似文献
4.
5.
对于广义Brouwer不动点问题的无界情形,研究者们主要针对凸集进行了一些研究,非凸集合还很少涉及。本文针对一类非凸集合,利用不动点问题的自映射以及新引入的二次连续可微映射构造了一组无界性条件,使得连续化方法能够求解无界非凸集合上的广义Brouwer不动点问题,并取得了该方法的全局收敛性结果,从而导致了可数值实现的全局收敛性算法。本文的研究结果在较大程度上推广了已有的研究结果,使得连续化方法能够处理更大一类不动点问题。 相似文献
6.
工程中常涉及到地基承载力特征值fa及桩端阻力qpa,作为同量纲的地基指标,对同一土层后者往往要比前者高得多。运用梅耶霍夫地基极限承载力理论,分析了随基础埋深的加大地基土破坏形式的变化,对浅基础及桩基础破坏形式、地基承载力特征值fa与桩端承载力特征值qpa作了对比。研究结果将有利于建立及区别地基承载力特征值及桩端端阻力特征值的物理概念,对实际工程具有指导意义。 相似文献
7.
最近学者们提出了组合同伦内点法(简记为CHIP方法)去求解一类非线性规划问题.在求解凸规划问题时,与内路径跟踪算法相比,文中在没有要求对数障碍函数是严格凸的以及解集是非空有界的条件下,取得了CHIP方法的全局收敛性结果.文中对CHIP方法进行了改进并利用改进的方法去求解更大一类的非凸规划问题.数值例子表明此改进是有效的. 相似文献
8.
对定型多参数系统定义Crawford数并研究其基本性质,所得结果有望在研究多参数系统特征值问题的数值分析中得到应用. 相似文献
9.
本文结合具体设计项目,通过对拟建工程点邻近已有的潮位资料进行分析,运用相关、对比、内插等方法,来推算无观测资料处的潮位特征值。经过验证,认为完全能满足设计所要求的精确度。 相似文献
10.
11.
本文给出了由运动物体所生成内波的基本方程组和对应的谱方程组。该方程组的线性部分是一具有体积源 (其下简称为体源 )的 Sturm- Liouville本征值问题 ,而它的非线性部分是由体源与线性波场相互作用的谱表示。在这类强迫方程的源项中包含了 10类内波谱 ,这些谱最终均可利用内波的振幅谱表示。本文给出了线性波场波要素的谱表示和运动物体生成内波的非线性谱方程可解性的讨论。为了检验所得到的谱方程组 ,文中又进行了该谱方程组线性部分的数值计算。 相似文献
12.
研究多参数系统单特征值及相应特征向量的向后误差及条件数。发展Hochstenbach和Plestenjak近期得到的一些结果。 相似文献
13.
In this work, a theoretical analysis of the dynamic response of a poro-elastic soil to the action of long water waves is conducted. For some combinations of the physical parameters of the soil and the water waves, the vertical stress tends towards zero at a certain unknown depth in the soil, as measured from the top of that medium. Under this condition, the liquefaction of the soil is imminent, at which time the excess pore pressure is essentially equal to the overburden soil pressure. Physical problems of this type have been widely studied in the specialized literature. However, most major studies have focused on solving the governing equations together with a liquefaction criterion. Here, the maximum momentary liquefaction depth induced by long water waves is considered as part of the problem, which is treated as an eigenvalue problem. To solve this problem, the governing equations are written in dimensionless form. The theoretical results show that for long waves, the horizontal displacements are smaller in magnitude than the vertical displacements, and when the wavelength or wave period increases, the maximum liquefaction also increases. Analytical solutions for the excess pore pressure and the horizontal and vertical displacements are obtained. The analytical results for the pore pressure are found to be very close to the analytical results reported in the specialized literature. 相似文献
14.
准确预测波浪透射对于维护港内水域平稳、保障港内船舶稳定具有重要意义。基于567组透浪试验数据,采用基因表达式编程(gene expression programming,简称GEP)算法预测波浪透射。主要研究内容包括:确定GEP算法的最优输入变量组合;建立透浪系数与最优组合变量的定量关系;探究GEP算法的预测精度随训练组数变化的规律;并对输入变量进行了敏感性分析。研究结果表明,GEP算法的最优输入变量组合为深水波陡、相对堤宽和相对水深;训练组数较少时,GEP算法的预测精度不高,当训练组数提高至300组,预测的精度已经达到较高水平,且精度随着训练组数的继续增加提高不大; GEP算法的预测精度远远高于前人的经验公式;相较于相对堤宽和相对水深,深水波陡对波浪透射影响更为显著。本研究表明,GEP算法可作为一种新的方法研究波浪透射,为后续研究与应用提供参照。 相似文献
15.
A wave transformation model (RIDE) was enhanced to include the process of wave breaking energy dissipation in addition to water wave refraction, diffraction, reflection, shoaling, bottom friction, and harbor resonance. The Gaussian Elimination with partial Pivoting (GEP) method for a banded matrix equation and a newly developed bookkeeping procedure were used to solve the elliptic equation. Because the bookkeeping procedure changes the large computer memory requirements into a large hard-disk-size requirement with a minimum number of disk I/O, the simple and robust GEP method can be used in personal computers to handle realistic applications. The computing time is roughly proportional to N1.7, where N is the number of grid points in the computing domain. Because the GEP method is capable of solving many wave conditions together (limited by having the same wave period, no bottom friction and no breaking), this model is very efficient compared to iteration methods when simulating some of the wave transformation process. 相似文献
16.
ABSTRACTIn this research, group method of data handling (GMDH) as a one of the self-organized approaches is utilized to predict three-dimensional free span expansion rates around pipeline due to waves. The GMDH network is developed using gene-expression programming (GEP) algorithm. In this way, GEP was performed in each neuron of GMDH instead of polynomial quadratic neuron. Effective parameters on the three-dimensional scour rates include sediment size, pipeline geometry, and wave characteristics upstream of pipeline. Four-dimensionless parameters are considered as input variables by means of dimensional analysis technique. Furthermore, scour rates along the pipeline, vertical scour rate, and additionally scour rates in the left and right of pipeline are determined as output parameters. Results of the proposed GMDH-GEP models for the training stages and testing ones are evaluated using various statistical indices. Performances of the GMDH-GEP models are compared with artificial neural network (ANN), GEP, GMDH, and traditional equations-based regression models. Moreover, sensitivity analysis and parametric study are conducted to perceive influences of different input parameters on the three-dimensional scour rates. 相似文献
17.
An open uniform B-spline-based panel method is developed for solution of potential flow problems. In this method, both geometry as well as the field variables are represented by the same open uniform B-spline basis function. The method is initially applied for the radiation problem in unbounded fluid. Computed results for a spheroid of different aspect ratio are found to be in excellent agreement with analytical results. The method is then applied for diffraction problem formulated based on the transient (time-domain) Green's function. Computed results for a hemisphere and Wigley hull are compared with published results and the comparison shows good agreement. 相似文献
18.
This study gives a new analytical solution for wave reflection and transmission by a surface-piercing porous breakwater. Velocity potential decompositions in the breakwater are used to obtain the solution. Different from traditional solutions, the new solution needs no complex dispersion relations (complex wave numbers) for wave motion through porous media. Thus, difficult procedures in traditional solutions for solving complex dispersion relations and handling non-self-adjoint eigenvalue problem are avoided. The calculated results of the new solution are in very good agreement with those of traditional solutions and multi-domain boundary element method solutions. 相似文献