case10year

利用时域有限差分求解CFD问题，其中差分格式为LUSGS，是求解流体问题的理论基础(Solved using finite-difference time-domain CFD problems, in which the differential form LUSGS )

适用于ABAQUS的自定义材料子程序，适用于Johnson-Cook材料模型(Apply to custom material ABAQUS subroutine for Johnson-Cook material model)

变增益PID算法的c++实现，目前PID算法较多的是c代码写的，这里上传一个C++的(Variable gain PID algorithm c++ to achieve, the current is more PID algorithm code written in c, where a C++ From the)

二阶微分方程组，采用龙格库塔法求解，将二阶降为一阶之后在求解。(Second-order differential equations, using the Runge-Kutta method to solve the second-order reduced to an order after solving.)

一元线性回归，数值分析方面可参考(one yuan linear regression, numerical analysis can look at the reference)

对实际采集的舰船辐射噪声进行了demo谱分析，分别采用了窄带解调和宽带解调两种方式，得到了较清晰的轴频和叶频信息。(use narrow-band and broad-band methods to demodulate the ship-radiated noise which is actually colleted, there can see clear axle frequency and blade frequency in the demo spectrum.)

fortran cases for BEM

己知一些离散的点，使用matlab利用最小二乘法拟合(Had a number of discrete points, with linear least squares fitting)

计算重力异常,只需要输入最大重力场模型的最大阶数以及重力场模型文件名在程序里设置经纬度范围和间隔即可得到重力异常(Gravity anomaly)

天线组阵中相位差的递推最小二乘估计与滤波(Phase array antenna group recursive least squares estimation and filtering)