查询词典 method of perturbation

In modern physics research, the calculus of variations has a broad application of law. As a solid mechanics, structural mechanics and computational mechanics of the theoretical foundation, it has important value in theory and practice on the mechanics; Variation method ruled out the perturbation of the restrictions can be widely used in many state-level and the state function in the calculation in the optical; Calculus of variations can be calculated with the parameters, we can guarantee the reliability of the results, can effectively reduce the workload of calculation, It can be said that the applications of calculus of variations are very broad.

在现代的物理学研究中，变分法有着广泛的应用：在力学上，变分法作为固体力学、结构力学及计算力学的理论基础，在理论上和实践上都有重要的价值；在光学上，变分法排除了微扰法的限制，可以广泛应用于诸多定态能级和态函数的计算中；在量子力学的应用中，具有可算出系统的参数，既可以保证计算结果的可靠性，又能有效地减少计算的工作量等的优点，可以说变分法的应用领域十分广阔。

Simultaneously, small parameter perturbation methods are employed to transform the problem of elastic wave scattering in cylindrical shell with a cutout into the iterative addition of a series of boundary value problems and to give a semi-analytical method for solving this problem.

同时，采用摄动方法，将含孔柱壳弹性波散射问题化成一系列边值问题解的迭加，给出分析求解本问题的半解析方法。

In the proposed method the data from state estimation or power flows during larger time interval is used to calculate nodal voltages and the initial value of current transitive-relationship matrix; the variation of diagonal elements of this matrix reflects the variations of the detailed models of system components, network topology and parameters after the perturbation, then by use of the PMU measured data in millisecond level the primary diagonal element can be modified.

该方法采用时间间隔较大的状态估计或潮流数据计算节点电压和电流传递关系矩阵的初值，并利用该矩阵主对角元的变化反映受扰后系统各元件的详细模型、网络拓扑和参数的改变，然后使用相量测量单元毫秒级的量测数据对其进行修正，从而为在实际应用中将相量测量单元与SCADA系统相结合做出了有益探索。

This paper mainly consists of three parts:(1) Based on the Reddy's higher-order shear deformation plate theory and general von Kármán-type equations, put forward the governing equations of pre- and post-buckled vibration of several hybrid FGM plate forms which have not been studied adequately, triumphantly applying the perturbation technique combined with Galerkin method into equations solving, and get the comparatively simple result forms with complicated deduction at last;(2) As a new type of materials, piezoelectric fiber reinforced composite actuators were applied to optimal vibration control, interrelated informatons be depicted in this paper;(3) During the investigative cource, some factors not been considered adequently in other researches were discussed fully in the postbuckled vibration analysis, such as the temperature-dependent material coefficients, heat conduction and nonlinear vibration characteristic etc.

本文的研究工作主要包括：(1)基于Reddy高阶剪切变形板理论和广义Kármán型方程，给出了几类现有研究成果较少或没有彻底解决的FGM混合板结构的屈曲前和屈曲后振动特性研究的控制方程，成功将摄动-Galerkin混合法应用于求解过程，并给出了各控制方程相对直观且易于计算的解析解形式；(2)单向压电纤维增强复合材料(Piezoelectric Fiber Reinforced Composite，简称PFRC)是一种新型压电材料，本文将其应用到了结构振动控制研究当中，发现通过压电纤维体积含量的选择可以实现混合板结构的优化振动控制；(3)围绕几种有代表性的FGM混合板结构，讨论其屈曲后的振动特性，在分析中同时考虑热传导，材料物性参数的温度相关性，以及机/热/电荷载耦合效应对非线性振动特性的影响，最后给出了大量数值计算结果。

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。

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。

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。

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。

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如果有任何问题，你可以随时联系我。