模态的

The equations of dynamics for the balance are established by Kane's method, from which derives the characteristic equation of natural frequency by means of linearization of dynamic equations, and the six natural frequencies being developed according to the theory of vibration. The law of the six natural frequencies varying with mass of the upper platform and the stiffness of the elastic element are presented,and the Finite Element Method is employed to testify the validity of theoretical results.

基于 Kane 方法研究天平的动力学及模态，通过线性化动力学方程建立天平的固有频率方程，依据振动理论推导出并联天平的六阶固有频率及其对应的振型，同时研究了天平的六阶固有频率随敏感单元刚度系数及上平台质量的变化规律，并用有限元法验证理论计算结果的正确性。

Finally, analysis and discussion in dynamic stability of nipper mechanism show that instable regions become wider with speed increasing and the chief factor determining motion stability of nipper mechanism is its first two modes which can be changed by adjusting the ratio of the length and inertia.

最后利用该参数平面分析了钳板机构的稳定性，分析表明，随着速度的提高，不稳定区域越来越宽；影响钳板机构稳定性的主要原因是机构的前两阶模态，可以通过调整构件的长度比、惯性矩比来提高钳板机构运动稳定性。

These methods cannot be used in the considered problem for at least two reasons:(1) they all work in off-line mode,(2) if the time series properties vary in different regions of the data set.

这些方法不能够被用于那考虑过的问题为至少二个理由：(1)他们所有的在脱机的模态中的工作，(2)如果时间系列特性在数据的不同区域中改变组。

These methods cannot be used in the considered problem for at least two reasons:(1) they all work in off-line mode;(2) if the time series properties vary in different regions of the data set, there is no single ''best'' structure for the whole series.

这些方法不能够被用于那考虑过的问题为至少二个理由：(1)他们所有的在脱机的模态中的工作；(2)如果时间系列特性在数据的不同区域中改变组，没有独身者''最好''结构为那全部系列。

This paper investigates the several key problems in calculating reliablity with direct numerical integration and completes a direct numerical integration program, and conducts some parameter analyses.

在计算过程中发现JC法在计算一些比较复杂的结构问题时有一定的局限性，特别是在计算非线性的极限状态方程和解决多模态相关问题的可靠性时，存在着较大的误差。

In this paper , the membrane and protector stresses of the laminated membrane coupling , the modal of the laminated membrane coupling , the stress character of the rabbet have been studied by ansys based on the nonlinear finite element method . the work of this paper makes a theoretical basis for the using of the coupling . it has several parts to follow

本文运用非线性有限元分析方法，利用有限元分析软件ansys研究了某型叠片联轴器的叠片及护板的应力分布、叠片联轴器的模态以及叠片联轴器榫头的应力特征，为该型联轴器的使用提供了良好的理论基础。

In real flight, multiple sensors of aircraft engine control system may fault at a time. In order to solve this problem, a revised multiple-failure-hypothesis based testing is investigated. This approach uses multiple Kalman filters, and each of Kalman filter is designed based on a specific hypothesis for detecting specific sensors fault, and then uses WSSR (Weighted Sum of Squared Residual) to deal with Kalman filter residuals, and residual signals are compared with threshold in order to make fault detection decisions. The simulation results show that the proposed method can be used to detect multiple sensors soft failures fast and accurately.

一般认为两个以上传感器同时发生故障的概率较小，但实际上不能排除其发生的可能性；提出了一种改进的多重故障假设方法来解决航空发动机控制系统多传感器同时发生软故障的问题，这一方法采用一组卡尔曼滤波器，每个滤波器对应一个被检测传感器的故障模态；采用残差加权二乘方处理滤波残差并与门限值作比较来判断是否发生故障；仿真结果表明，所提出的方法能有效解决多传感器软故障的检测与隔离问题。

It is found that the validity of modal series method and linear modal method is not influenced by the second-order resonance condition, which has a great influence on normal form method. When the operating condition is near the second-order resonance condition, the valid area of normal form method is quite small.

发现模态级数法和线性模式分析法的有效性均不受系统共振的影响，而正规形法的有效性受系统共振情况的影响较大，在系统的2阶共振点附近，其有效域面积较小。

On the problem of model parameter determination, the singularity distribution method is used to derive the expressions for numerically calculating the added mass arised from vibration of the structure under three-dimensional case; The aero-dynamic damping ratio is identified from the testing data based on the methods of empirical mode decomposition, improved random decrement and Hilbert transformation; The reduced-order spectral representation method is also deduced in this chapter based on the technique of proper orthogonal decomposition.

在模型的参数计算上，采用奇点配置法推导了三维情形下结构振动诱导流场附加质量的数值计算方法；联合采用经验模态分解、改进的随机减量法及Hilbert变换对索穹顶结构的气动阻尼进行了识别分析；推导了基于本征正交分解的降阶谱解法。

Statistical Energy Analysis is a module measure, which use relationship of energy flow to evaluate dynamics, vibrating response level and sound radiation of the mulriple and syntonic assembly structure.

统计能量分析是个模块化方法，它运用能量流关系式对复合的、谐振的组装结构进行动力特性、振动响应级及声辐射的理论评估，SEA特别适用于高模态密度的高频区，传统的数值计算方法如有限元和边界方法对应力和振动建模获得了很大成功，但对噪声应用存在明显的局限。

Finally, according to market conditions and market products this article paper analyzes the trends in the development of camera technology, and designs a color night vision camera.

最后根据市场情况和市面上产品的情况分析了摄像机技术的发展趋势，并设计了一款彩色夜视摄像机。

Only person height weeds and the fierce looks stone idles were there.

只有半人深的荒草和龇牙咧嘴的神像。