模态系统

To evaluate the precision of solutions obtained by modal series method, normal form method and linear modal method, an error index describing the approximation to the nonlinear simulation is defined and then applied to the same system.

为比较模态级数法、正规形法和线性模式分析法所得解对时域仿真解的逼近程度，定义一误差指标，并在4机2区系统中做相关分析。

In simple view mode, only the filename is displayed and thus each entry takes only one line of the screen:In extended view,the date of modification and size of the file are added (date and number of entries for a directory, size and free space for a drive):ShortcutsLong press on the numerical keyboard will also quickly move you to 9 predefined locations of the file system:1: C:2: E:3: Z:4: C:\Logs5: C:\Data6: C:\System7: E:\8: E:\Data9: E:\SystemThere is currently no way to modify customize these locations but we plan to introduce this in the future.

在简单的视野模态中，只有文件名被显示和如此每个进入拿只有荧屏的一条线：在广大的视野、修正的日期内和文件的大小被增加(日期和进入的数字为一个目录，大小和自由的空间为驾驶)：ShortcutsLong 杂志报纸在数字的键盘上也将会很快地移动你到文件系统的 9个被预先定义的位置：1： C：2： E：3： Z：4： C：\ Logs 5： C：\ Data6： C：\ System7： E：\8： E：\ Data9： E：\ SystemThere 是现在没有方法修正定制这些位置但是我们计划未来介绍这。

The method in this paper is verified through ANSYS, by using the finite element modal analysis. The calculation for the derrick of an oil drilling rig shows that the error is not exceeding 1\%.

通过ANSYS有限元分析对该估算方法进行了验证，并在石油钻机井架底座的有限元模态分析中应用该方法对系统固有频率进行了估计，误差均不超过1\%。

By use of the identification information, the poorly damped area and the regions of the grid affected by the mode are detected on-line.

利用辨识出的模态信息，可以在线监测大规模电力系统阻尼薄弱区域并及时发现故障发生区域。

Sufficient conditions of linear and quadratic feedback stabilizability are obtained for nonlinear systems with uncontrollable critical mode (a single zero eigenvalue, or a pair of pure imaginary eigenvalues), corresponding algorithms are given for constructing stabilizing laws.

结合中心流形方法和范式理论研究了临界情形下非线性系统的稳定性问题，针对临界模态为单零特征值、一对纯虚特征值和一对零特征值的情形，分别获得了渐近稳定或不稳定的充分条件，给出了相应稳定性判据。

In order to investigate the excitation mechanism and response characteristics of wind-rain induced vibration of stay cable,an instrumentation system of wind-rain induced vibration measurement,which consists of anemometer,rain gauge and accelerometer,was installed on the Dongting Lake Bridge,Yueyang,China.

为了研究斜拉桥拉索风雨振的机理及响应特征，在岳阳洞庭湖大桥建立了由风速仪、雨量计、加速度传感器组成的风雨振现场观测系统，观测到了多次拉索风雨振现象；得到了发生拉索风雨振时风速、风向及雨量的基本条件，分析了风雨振时拉索振动的幅值、主振频率、模态参与特性及空气动力负阻尼比等响应特征。

A bstract: This paper focus on virtual instrument design of modal parameters identification with curve fitting theory based on rational fraction orthogonal polynomials. Using Forsythe orthogonal polynomials solves the coefficient equation instead of normal power polynomials in order to decrease the morbidity of it, making the orders of coefficient equation reduce to half and increasing computing efficiency.

本文基于有理分式正交多项式曲线拟合理论对振动系统的模态参数辨识进行了虚拟仪器的设计，为了减少系数矩阵的病态，采用 Forsythe 正交多项式代替普通的幂多项式进行求解，使系数矩阵阶次降低近一半，提高了运算速度。

The relationship between the relative sensitivity of natural frequency and energy distribution has also been established for nondamping systems.

为了使显示的图形比较清晰和美观，本文还开发了CGE400显示器/卡的高分辨率彩色显示功能，最后将这些功能软件有机地结合在一起，从而构成微机实验模态分析软件系统。

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。

Secondly,for nonlinear vibratory systems,the relationship between a class of stationary geodesics of the Riemannian manifold and the nonlinear normal modes is found.

进而，将类似的对应关系推广应用到非线性振动系统中，得到了非线性模态与 Riemann 流形上的极值测地线之间的对应关系。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。