space-timecodingproject

This code measures the perimeter of the land.

输入两幅图像，利用已经过修正的数值计算其PSNR值，经修正的指数值(input 2 pictures and culculate the PSNR of them (The correct one))

用龙贝格法求定积分，此例的变量数为三，但整体思路是没错的。(With Romberg method for the definite integral, the number of variables in this case is three, but the overall idea is correct.)

混沌现象的基于matlab所进行的编程，实现了简单的运算(file for )

Data Encryption by Matrix Multiplication We will only use numbers 0 to 26 for the encryptive mathematics operation. Numbers from 1 to 26 are for letters from A to Z and 0 is for all non-letter characters. To minimize usage of numbers, all letters are converted to upper case. The original message is converted to number array according to the ASCII table and minus 64. We partition whole array into blocks of 8 numbers. The last block may be added several zeros. Then multiply each block by the an 8x8 matrix A which is invertible in Z27 to get cipher data. The decryption is the same process except to use its inverse matrix B. For good visual reading, we convert all non-letter characters to under score for the decryption.

基于EMD的直流电机换向电流提取程序。内含用LEM公司的霍尔传感器实测的微型直流电动机启动时的电流信号（真实的数据和大家分享），分别用小波滤波和EMD消噪，并用EMD提取直流分量、高频换向电流，对研究电机间接测速、启动特性测试很有帮助，对电机故障诊断也有帮助。(EMD-based DC motor commutation current extraction procedures. LEM s included with Hall sensors measured miniature DC motor start-up current signals (real data and to share), respectively, with wavelet filtering and EMD de-noising and extracted DC component with EMD, a high-frequency current commutation of indirect research motor speed, starting characteristics testing is helpful, for motor fault diagnosis can also help.)

MPPT code for particle swarm optimization

说明：  一种改进型遗传算法。主要利用多种群协同竞争的方法，来提升算法的精度和鲁棒性，避免算法不成熟而导致提前收敛。(An improved genetic algorithm.The method of multi-group cooperative competition is mainly used to improve the accuracy and robustness of the algorithm, and avoid the premature convergence of the algorithm.)

DFT IDFT stands for discrete time fourier transform and inverse fast fourier transform

使代码框文字可以中文高亮，达到方便阅读功能(Chinese characters can make the code box highlighted, to facilitate the reading function)