At the same time, we refrain mirror frequency effectively with the method of digital quadrature modulation ( DQM). 同时,由于采用了数字正交调制,从而有效地提高了镜频抑制。
A kind of unconditionally stable higher-order accurate time step integration algorithms has been applied, of which the numerical solutions are found to be equivalent to the generalized Pade approximations, for second-order initial value problems based on the differential quadrature method ( DQM). 采用了一种高阶精度的Pade逼进的时间域上格栅取点的时间步积分的微分求积方法,对双质点系及梁在强迫力作用下的振动特性进行了数值分析。
Then, using the second-order central difference to discretize the time derivative of the displacement, and applying the quadrature formula to the mass matrix, a fully discrete lumped mass Morley element method is developed for the same problem. 然后利用中心差分格式离散时间方向的二阶导数,再利用适当的求积公式得到薄板弯曲问题的集中质量Morley元全离散格式。
A Method for Real Time Correcting the Amplitude and Phase Errors of UWB Quadrature Demodulation Receivers 一种正交解调超宽带接收系统幅相误差实时校正方法
Analytic formulations of matrix elements for constant elements and linear elements are derived. More computation time is saved than a 4-point Gauss quadrature rule by Brebbia. 本文对常数元和线性元均导出可供计算矩阵元的解析公式,因此比Brebbia采用的四点Gauss积分法大大缩短了计算时间。
In order to solve the problem of low accuracy in measuring time difference in SAW based wireless sensor system, a method of digital quadrature demodulation is presented. 提出了采用数字式正交检波技术得到I、Q通道的方法,以此来测量相位,获取传感信息,很好地解决了在无线声表面波传感器测量系统中测量时间差精度低的问题。
In this dissertation, nonlinear mathematical models of visco-elastic plates with finite deformations and the effect of higher-order shear deformations are established. At the same time, an extended differential quadrature method is formulated. 本文在有限变形条件下,建立了考虑高阶横向剪切效应的粘弹性板非线性分析的数学模型,建立了相关的微分求积方法;将微分求积方法推广以便对上述非线性问题进行数值分析。