Analyzed the mechanism of production and harmfulness of the rolling bearing vibration, the method of the dynamic gray discrete forecast model was successfully applied in the forecast of the rolling bearing vibration.

The influence of the modal dispersion of signal fiber on velocity measurement in VISAR applications;

The paper compares the structural parameters and amount of modes between multimode fiber and polymer optical fiber,then analyses that a large amount of modal dispersion seriously limits the bandwidth of the fiber.

Both the modal dispersion characteristics and cut off conditions are investigated through numerical and analytical approach.

Through the establishment of different physical and dispersion models,The effects of the surface and interface on spectroscopic ellipsometry were inspected.

A major limitation on the bandwidth of multimode glass and plastic optic fibers is modal dispersion, in which different optic modes propagate at different velocities and the dispersion grows linearly with length.

For different aspect ratios of the elliptical core, effects of chirality parameter on the characteristics such as dispersion curves, birefringence and modal dispersion of the fundamental modes in the elliptical.

The normalized birefringence and modal dispersion as functions of normalized frequency for different aspect ratios are presented and compared with Guassian approximation.