查询词典 method of perturbation

The calculation of the rotordynamic coefficients of a multistepped annular seal in hydraulic turbines is discussed in this paper. Based on the Hirs' turbulence lubrication theory and the bulk flow model, the governing equations for the flow in the seal are developed by using the Moody's friction equations. The governing equations are perturbed when the rotor and the stator are coaxial. The Runge Kutta integration method and the Newton Raphson iteration method are used to solve the perturbation equations....

本文首先在Hirs紊流润滑理论的基础上，采用体积流动模型及Moody摩擦方程建立起阶梯口环水封中流体流动的控制方程，将各个方程在转子与定子同心处进行摄动，采用Runge－Kuta积分法及迭代过程求解摄动方程，建立起水轮机阶梯式口环水封的转子动力特性系数的计算方法，为水轮发电机组轴系的动力学分析提供了必要的理论基础。

In this paper we separate the Hamiltonian into three parts: a spherical symmetry Hamiltonian; a z-component of the angular momentum operator, and a non-spherical symmetric potential as the perturbation operator, and provide a propose method by separating the potential containing squared magnetic field B^2 into two parts spherical symmetric and non-spherical symmetric ones so that the first-order energy correction due to the non-spherical symmetric potential is zero, and the second-order correction due to B^2 can be obtained by a simple variational method.

采用变分法和微扰法相结合的方法，把高强度磁场中氢原子的哈密顿H分为三部分：球对称哈密顿；z分量角动量算符相应部分和非球对称势微扰，并用一种特别规定的分解法将哈密顿H中含磁场平方项的势能分解为球对称与非球对称两部分，且使非球对称部分引起的一级修正能量值为零，并采用一种简便的变分法直接求出B^2对能级的二级修正值。

In this paper, the maximum likelihood algorithm with process and measurement noise for nonlinear continuous-discrete system given by Jategaonkar and Plaetschke is improved in two aspects: 1 to avoid the disadvantages of sensitivities computation by common finite-difference method, in which the perturbation sizes should be selected optionally, an improved finite-difference method with best perturbations, is presented. 2 to improve the numerical stability of Jategaonkar's algorithm, maximum likelihood algorithm with fast triangular square-root decomposition filter is given.

摘要对Jategaonkar等人给出的同时计及过程及观测噪声的非线性连续-离散系统的极大似然算法从两个方面进行了改进：1给出了计算灵敏度的最佳摄动有限差分算法，避免了普通有限差分法计算灵敏度矩阵时需人为选择参数摄动量大小而带来的缺点；2给出了具有快速三角化平方根滤波的极大似然算法，提高了原算法的数值稳定性。

In order to analyze the stiffness of 3D 4 directional braided composites, the homogenization theory based on the multi-scale perturbation theory was used as the basic theory. The virtual displacement principle was used to educe the homogenization formulation of effective elastic modulus and the schemes to solve the problem using finite element method. The effective elastic modulus of 3D braided composites were predicted by this method and the calculation results agree quite well with experiment results.

在对三维编织复合材料刚度性能的分析过程中，以基于小参数渐近展开和多尺度摄动方法的均匀化理论为理论基础，用虚位移原理导出了等效弹性模量的均匀化列式及其有限元求解方程，从而通过细观和宏观有限元的数值分析方法预测了三维四向编织复合材料的等效弹性模量，预测结果与实验结果较为吻合。

In the sense of Von Karman large displacement, the governing equation of nonlinear dynamic response of the clamped circular plates under impact of a mass is established by using the virtual displacement principle and Galerkin's method in this paper. The effect of coupling between the impact load and the displacement of. the circular plates is considered. The governing equation is solved by applying the time increment method and the singular perturbation theory, and the asymptotic solutions of nonlinear dyna...

本文在Von Kármán大位移的意义上，利用虚位移原理伽辽金方法建立了圆板在物体撞击下的非线性动力响应的控制微分方程，在研究响应问题时，考虑了冲击载荷与圆板位移响应之间的耦合影响，文中使用时间增量法和奇异摄动理论求解问题的控制方程，获得了固支圆板非线性动力响应的近似解，并且求解了具体算例，绘出了圆板位移、应力响应曲线以及冲击力随时间的变化曲线。

Through the comparison, we use traveling-wave method to measure dispersion and nonresonant perturbation method to measure interaction impedance.

测量系统采用虚拟仪器的设计思想，由测量平台、伺服电机、矢量网络分析仪、计算机等硬件组成，用LabView完成了系统软件设计。

The advantages and disadvantages of balanced truncation, singular perturbational method and generalized singular perturbation are analyzed. A quasi-generalized singular perturbational model reduction method is proposed.

分析了平衡截断法、平衡奇异摄动法和广义平衡奇异摄动法存在的优缺点，提出了一种近似广义奇异摄动模型降阶算法。

Based on this method, simulation results show that the closed-loop mobile robot system has not only the robust stability but also the perfect robust performance of tracking. The proposal of this method vanquishes the shortcomings of other methods designing controllers only for exact models, which can not ensure the system′s performance under internal perturbation.

仿真结果表明，基于此方法设计的控制器能保证移动机器人闭环系统不但具有鲁棒稳定性而且能很好地跟踪给定轨迹，具有鲁棒性能，从而克服了其他学者仅对系统精确模型设计控制器而导致系统出现内部摄动时，不能保证系统性能的缺陷。

Based on mass-spring model, a method of automatic mode-selecting method is presented to solve the difficulties of selecting corresponding modes close to the excitation frequency, in adaptive perturbation for mistuned bladed disks.

摘要针对自适应摄动法在失谐叶盘受迫振动分析中，选择接近激振力频率的相应模态数目难于控制的问题，基于质量－弹簧模型，提出一种自动选择模态的方法。

The perturbation method combined with multipole expansion method to calculate the head-related transfer functions of the snowman mode approximately, and the effects of the torso scatterings and reflections on HRTFs are analysed quantitatively.

本文提出微扰与多极展开相结合的方法，近似计算雪人模型近场头相关传输函数，并利用此方法定量分析躯干散射声波对HRTF的影响。

"Please accept this talisman as a token of our thanks."

请收下这个护身符以表达我们的感谢。

If I have that magic, I will be more acceptable in the society.

如果我拥有那种魔法，我将更加被这个社会所容纳。