v21i04.R

说明：  R Programming implementation of panel smoothing threshold regression model

说明：  进行了常微分方程的建立，并模拟出经典的SIR模型曲线(The ordinary differential equation is established and the classical SIR model curve is simulated)

成都市空气中的O3来源及分析，可用于大创项目(O3 source and analysis in air of Chengdu, which can be used in some projects)

说明：  因子分析:包括案例和对应的R语言代码，代码中地址需要自行修改后使用(Factor analysis: including a case and corresponding R language code, the address in the code needs to be modified by itself)

说明：  R语言对数据进行Garch-M-Copula建模并利用EM算法估计相应的参数(Garch-m-copula is used to model the data in R language and EM algorithm is used to estimate the corresponding parameters)

利用R语言SEM程序包进行通径分析，简单易学，容易上手(SEM path analysis model)

一篇论文的GARCH in mean VAR(GARCH in mean VAR of a published paper)

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)

说明：  garch copula 带论文和code例句(garch copula with paper and code)

these of diagnosis electrical machine