AHP

找出只出现一次的数字，其他数字均出现了2次，时间空间尽量少(Identify only appears once, while other figures have appeared two times to minimize time and space)

一个简单的类似于豆瓣的电影网站(A simple website similar to Douban)

说明：  % Input: XY(n,2) is the array of coordinates of n points x(i)=XY(i,1), y(i)=XY(i,2) % % Output: Par = [a b R] is the fitting circle: % center (a,b) and radius R % % Note: this fit does not use built-in matrix functions (except "mean"), % so it can be easily programmed in any programming language

说明：  相场模拟计算的matlab程序，模拟沉积过程中的结构演化(Phase field simulation of matlab procedures)

说明：  燃料电池等效模型，可以看出电流与电压输出变化关系(According to the equivalent model of fuel cell, the relationship between current and voltage output can be seen)

MAYA 4-5 X文件导出插件的代码，很好的东西，可以方便大家！快下吧！-MAYA 4-5 document derived X plug-in code, good things can facilitate all! Under fast!

已经编译好的中文版大漠模块 无需注册 直接在易语言里加入模块即可使用 涵盖90%命令(The already compiled Chinese version of the desert module does not need to be registered)

说明：  工程信号处理MATLAB分析程序，包含傅里叶变换、相关性分析、功率谱分析。(Engineering signal processing MATLAB analysis program, including Fourier transform, correlation analysis, power spectrum analysis.)

简单的代码，里面是一些增删改查操作适合刚学习的朋友(Simple code, there are some additions, deletions, modifications and checks for new friends to learn)

双重差分估计 双重差分模型（difference-in-difference，DID）近年来多用于计量经济学中对于公共政策或项目实施效果 的定量评估。 通常大范围的公共政策有别于普通科研性研究，难以保证对于政策实施组和对照组在样本分配上的完全随机。非随机分配政策实施组和对照组的试验称为自然试验（naturaltrial），此类试验存在较显著的特点，即不同组间样本在政策实施前可能存在事前差异，仅通过单一前后对比或横向对比的分析方法会忽略这种差异，继而导致对政策实施效果的有偏估计。(Quantitative evaluation of policy or project implementation effect. Generally, a wide range of public policies is different from general scientific research, and it is difficult to ensure that the sample allocation for the policy implementation group and the control group is completely random. The non-randomly assigned policy implementation group and the control group are called natural trials, which have significant characteristics, i.e. there may be prior differences between the different groups of samples before the implementation of the policy, and this difference will be ignored only through a single pre-and post-comparison or horizontal comparison analysis method, which leads to the policy. Biased estimation of implementation)