janming_v79

格子玻尔兹曼 圆柱绕流 Python编写(lattice boltzmann flow around a cylinder, using Python. very fast because of numpy library)

混沌仿真CHEN系统仿真，陈关荣老师的混沌系统。(y_e2 = c*y_h + (c - a)*(x_0+(h/2)) -(x_0+(h/2))*(z_0+(h/2));)

说明：  计算两组向量之间的旋转矩阵。输入参数为在两个不同坐标系中的同名向量（模为1），返回参数是一个3X3的旋转矩阵。(The function of RM realize the rotation between two sets of vectors, whose magnitude are 1, defined in two different refrence frames. Input parameters are two sets of vectors r and b, return value is a rotaton matrix.)

可实现OFDM电力载波通信的前导序列检测，能进行连续多个前导检测(Can achieve OFDM power carrier communication leading sequence detection, can carry out a number of continuous preamble detection)

首先根据高斯白噪声频率充满整个频带的特性，通过双树复小波包变换对高斯白噪声进行分解，利用频带能量泄漏的定量分析方法，验证了双树复小波包变换具有较低的频带能量泄漏特性；其次利用双树复小波包变换逐层分解信号，对每层分解所得分量求其FFT谱的峭度，得到基于双树复小波包变换的谱峭度图，根据图中峭度最大的原则，可以自动准确的选择信号分解最佳层数和最佳分量；最后将基于双树复小波包变换的谱峭度图的故障诊断方法应用于实际工程中，对齿轮故障振动信号进行分析，选择最佳分解层数和分量后利用希尔伯特包络解调，有效准确地提取了故障特征信息，验证了方法的可行性和有效性(The parameters of a filter were determined by experience, and that has a great influence on the results of signal processing. The discrete wavelet packet transform has a larger energy leakage of frequency band, which obviously affected the results of the envelope demodulation. It is necessary to have a method with a lower energy leakage of the frequency band before envelope demodulation. The dual tree complex wavelet packet transform (DT-CWPT) was a new signal processing method that had many good qualities. Because the energy leakage of the frequency band was smaller when the signal was decomposed by a dual tree complex wavelet packet transform, the dual tree complex wavelet packet transform was used to extract the fault feature information in the field of fault diagnosis. In this paper, first, according to the characteristics of Gaussian white noise, whose frequency was full of the whole frequency band, Gaussian white noise was decomposed by a dual-tree complex wavel)

利用MATLAB实现了16位快速傅立叶变换，并与自包含函数进行了比较。(The 16-bit Fast Fourier Transform is realized by using MATLAB and compared with the self-contained function.)

说明：  代码为偏最小二乘法计算过程的代码，主要部分都有中文解释(Code for the calculation process of partial least squares method)

Ridge Regression RR 岭回归估计，是非常有用的非线性时间序列算法，在局部多项式预测中非常有用。(Ridge Regression RR ridge regression estimates, it is useful to nonlinear time series algorithms, in Local Polynomial prediction in very useful.)

离散数据生成tin的优秀代码，注释多，易于学习和移植(Discrete data generated tin excellent code, comments, easy to learn and transplantation)

牛顿 非牛顿流体数值模拟源代码，对粘弹性流体湍流减阻进行分析(Newton non-Newtonian fluid numerical simulation of the source code, to analyze the viscoelastic fluid turbulent drag reduction)