查询词典 perturbation parameter

Expanding the unknown function in a small perturbation parameter and using a successive expansion in a Taylor series for the water particle path and the period of a particle motion, the third order asymptotic expressions for the Lagrangian particle trajectories and the period of particle motion can be derived directly in Lagrangian form.

藉由一系列连续的Taylor级数展开，於考量波动场中各流体质点之运动轨迹与运动周期下，将已知的Eulerian解转换成完全未知的Lagrangian形式解。

Because of the universal existence of parameter perturbation and the fault ineluctability for actuator and sensor, it is more important and practical to study robust fault-tolerant control of parameter perturbation for linear system with time-delay.

由于参数扰动的广泛存在性以及执行器和传感器发生故障的不可避免性，使得研究具有参数不确定的时滞系统的鲁棒容错控制问题具有更重要的现实意义。

Some conclusions are obtained:(1) The interval data concept can rationally settle the apart component's dependence problem of monitoring data;(2) The survey point's displacement which is the material parameter's increasing function or deducing function can be used to back-analyse the material parameter's up and down limit; and (3) Both the interval parameter perturbation back analysis method and the interval parameter monotony back analysis method can obtain satisfactory interval parameters.

通过分析得出结论：(1)可利用区间数概念合理解决监测资料中分离分量相关性的问题；(2)可利用工程结构中位移为待反分析材料参数的增函数或减函数的测点位移的上、下限，来反演得到不确定性材料参数的上、下限；(3)工程算例分析表明，区间参数摄动优化反分析法和区间参数单调性优化反分析法都能得到令人满意的参数区间。

Moreover, the choices of the singular perturbation parameter are studied, and a new simple and convenient method to estimate the bound of the singular perturbation parameter is designed.

此外，本文还研究了奇异摄动小参数的选取，提出了一种新的简单易行判定稳定性界的方法。

Chapter 3 analyzes numerically the effects for orbit calculation caused by orbital perturbation, parameter error and so on. A precise mathematical model of orbit calculation is given.

第三章通过数值法分析了各项轨道摄动和参数误差等因素的对轨道计算的影响，给出了精确的月球探测器轨道计算数学模型。

In order to solve this model, perturbation method is employed and the solution is expanded into a series in powers of perturbation parameter.

利用小扰动方法处理了任意形状非均质油藏不稳定渗流问题，将解表达成关于扰动参数的无穷幂级数形式。

The eigenvalue problem of Dirac operator with perturbation Parameter is studied,the analyticity of perturbation parameter is discussed,and the analytic extension is done,at last,the expansion formulas of power serier about preradical expansion into perturbation parameter are got.

针对带有微扰参数的Dirac算子特征值问题，讨论了对微扰参数的解析性，并进行了解开拓，最后得到了预解核对微扰因子的幂级数展开式。

Chapter four studies the chaotic responses in a system consisting of simple pendulum and harmonic oscillator under bounded noise excitation. Firstly, the Melnikov function of the two-degree-of-freedom system under Hamiltonian perturbation is derived. The essential condition of the autonomous system for the probable onset of chaos is obtained, the Poincare maps of the system under small Hamiltonian perturbation and the effect of increasing perturbation on the Poincare maps are studies. Then for the non-autonomous system under damping and harmonic or bounded noise excitation, the largest Lyapunov exponent and Poincare maps are calculated. From the analysis of the largest Lyapunov exponent, the critical criterion for the onset of chaos, and the conclusion that the threshold of bounded noise amplitude for the onset of chaos in the system increases as the intensity parameter of Wiener process increases are obtained. The result from the analysis of Poincare maps is in agreement with that obtained from the Largest Lyapunov exponent. The effect of varying damping coefficient and intensity parameter of Wiener process is also analyzed.

第四章研究了有界噪声激励下的两自由度单摆—谐振子系统的混沌运动，首先推导了该两自由度系统仅在Hamilton扰动下的Melnikov函数，得到该自治系统可能产生混沌的必要条件；研究了该系统在小的Hamilton扰动和增大摄动情形下的Poincare截面；然后对有阻尼、谐和或有界噪声激励下的非自治系统数值计算了其最大Lyapunov指数和Poincare截面；从Lyapunov指数分析得到了这个两自由度系统产生混沌运动的临界条件及产生混沌的临界激励幅值随Wiener过程强度参数值的增大而增大的结论，Poincare截面分析的结果亦符合Lyapunov指数分析的结论；研究了Wiener过程强度参数、阻尼系数变化对Poincare截面的影响。

The dose enhancement effects and decreasing effects caused by material inhomogeneity were studied quantitatively with a parameter named Dose Perturbation Factor, which was the ratio of the dose at a point in the heterogeneous phantom to the dose of the same spatial location point in the homogeneous phantom. It was showed that the degrees of the dose enhancement or decreasing depended on the energy of radiation, field sizes of the beamlets and compositions of the media. The dose perturbation for high energy X rays is greater than that for low energy X rays. At the same energy condition, the dose perturbation decreased when the field size increased. And the relationship between them was not linear.

模拟结果表明：在小射野情况下，异质组织界面处出现了较大的剂量跃变，剂量扰动效应的强弱程度取决于射线的能量、射野的大小和模体介质的不同等多种因素，高能X射线条件下的剂量扰动效应大于低能X射线条件下的剂量扰动；在入射X射线能量相同的条件下，剂量扰动效应随射野尺寸的减小而增强，并呈现一种非线性关系。

Moreover,in this dissertation,a method ispresented to control safe basin with the fractal erosion,that is by the application ofthe weak parameter periodic perturbation with an optimal frequency to control thefractal erosion basin,and the analytical study shows that the essence of the methodis that the parameter periodic perturbation can be used to delay the occurrence ofhomoclinic tangencies.

并且在本文提出了一种对分形侵蚀安全域进行控制的方法，那就是应用具有最优频率的参数周期扰动对于已受到分形侵蚀的安全域加以控制，在理论分析中得到这种控制分形侵蚀安全域的方法实质上延缓了鞍点同宿相切的发生，同时考虑了外加噪声对控制后安全域的影响，得到这种控制方法具有很好的鲁棒性。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。