The Window functions of biorthogonal cosine wavelets are discussed.

The method uses the cosine filter(CF)and amplitude-frequency coefficient correction to filter out the real part of a phasor at the present sampling,and the imaginary part of the phasor at the a-quarter-period-before sampling.

In this paper,the wavelet analyses of ring laser gyro drift rate were implemented based on the Mallat algo- rithm in the wavelet analysis,the design of cosine filter is discussed.

Considering the nonlinear feature of wave in shallow waters,the cnoidal wave theory is used to calculate the wave force for submarine slope stability.

The velocities in the oscillatory boundary layer due to linear and cnoidal waves are simulated based on the incompressible D2Q9 model of the Lattice Boltzmann Method.

The problems of diffraction on porous multiple vertical cylinders by nonlinear water waves,such as cnoidal wave,solitary wave and second order Stokes wave,are analyzed.

Numerical solutions of the equations with the internal generation of sinusoidal and cnoidal waves confirm this finding.

The bottom boundary layer under cnoidal waves was studied by using Acoustic Doppler Velocimeter(ADV) technique in a laboratory flume.

It is well know that the Boussinesq equations, which govern the fluid motion in shallow-waters of constant depth, have analytical solutions of both cnoidal waves and solitary waves.