improve PI model

matlab的sift算法调用库，很简洁(The sift algorithm matlab library calls, very simple)

说明：  cluster selection based on fuzzy rules

Matlab code for one step ahead predictive control

循环谱的估算循环互相关函数计算循环互相关(cyclic cross periodogram)

模拟倒向随即微分方程，给出图形和用户说明，在学术研究中有一定的应用(Then simulated backward differential equations, graphics and user instructions are given in academic research in the application of certain)

本程序针对信号检测与估计中极大极小化准则的仿真，画出贝叶斯风险曲线、极大极小化风险等，帮助大家更好理解极大极小化准则。(This procedure for signal detection and estimation of the minimax criterion simulation, draw the Bayesian risk curve, greatly minimizing risk, to help you better understand the enormous minimization criterion.)

使用MATLAB设计滤波器，然后下消除指定位置消除消元(Design the filter with MATLAB, then eliminate the specified position to eliminate the elimination.)

18 Random Number Generation - a large collection of random number generators.

是对正弦波和三角波进行会识别的MATLAB程序(In sine wave and the triangle is to identify the MATLAB will)

运动学问题 平抛运动 自由落体运动 有无阻力情况等