Based on the parameters that identified by frequency response method,a disturbance observer was used to estimate the disturbance generated by the variation in model parameters and load in AC servo system.

The paper introduces a complete procedure using frequency response method to test the distortion of transformer s winding, including the principle, the determination of frequency, range, testing points, and criteria.

The model parameters of the motor speed-loop were identified with the frequency response method,the disturbance,that was produced by variation of system parameters,machinery nonlinear etc,was estimated,and which was feedback to input port as a compensation signal.

The two examples of the fault diagnosis of transformer winding deformation applying frequency response analysis are introduced.

Impulse Frequency Response Analysis (IFRA), as one diagnostic method of Frequency Response Analysis (FRA) which calculates and computes frequency dependent variables of the windings, is becoming a popular technique used to externally monitor and assess the condition and mechanical integrity of transformer winding.

The relationship between structure of polyurethane foam sandwich panels and the frequency response;

Frequency responses of the surface-acoustic-wave driving single-electron-transport device;

Analysis of frequency response of aero-engine flame-basket under dynamic load;