期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
AR Model Based on Time Series Modeling for Predicting Egg Market Price in 2021
1
作者 Min YAO Qingmeng LONG +4 位作者 Di ZHOU Jun LI Ping LI Ying SHI Yan WANG 《Agricultural Biotechnology》 CAS 2021年第3期89-93,共5页
Eggs,as a meat consumer product in China,are closely related to the vegetable basket project.Exploring and predicting the future trend of egg market price is of great significance for stabilizing egg price and market ... Eggs,as a meat consumer product in China,are closely related to the vegetable basket project.Exploring and predicting the future trend of egg market price is of great significance for stabilizing egg price and market supply.In this study,the time series AR model was used for fitting the egg market prices in the 66 d from January 1 to March 7,2021,and the delay operator nlag18 was used for white noise test,giving pr>probability of chisq<0.005.The time series was not a white noise series,and then the stationary series was used for modeling.The optimal model was selected as the AR series(BIC(3,0)),and finally,the egg market price model AM was obtained as X_(t)=9.0556+(1+0.8926)ε_(t),which was the optimal model.The model showed that the egg price fluctuations in 2021 will be clustered,and the later price will be significantly affected by external factors in the previous period.The dynamic prediction results of the model showed that the egg price would stop falling in March 2020,and the egg price would continue to slow down in March. 展开更多
关键词 Time series Autocorrelation coefficient Partial correlation coefficient AR model Egg market price
下载PDF
Thinking on Breeding of Fecundity Genes in Guizhou Black Goats Through Cost-benefit Analysis of Mutton Sheep by SAS Multivariate Stepwise Regression
2
作者 Qingmeng LONG Min YAO +4 位作者 Ping LI Shengli XIONG Ying SHI Yan WANG Di ZHOU 《Agricultural Biotechnology》 CAS 2021年第4期77-82,97,共7页
The total output value of mutton in Northwestern China has accounted for more than 60%of the total output value of animal husbandry over the years.It can be seen that the mutton industry in Northwest China not only pl... The total output value of mutton in Northwestern China has accounted for more than 60%of the total output value of animal husbandry over the years.It can be seen that the mutton industry in Northwest China not only plays a pivotal role in animal husbandry,but also plays an important role in Chinese agriculture.In this study,based on cost accounting theory,income-related theories and total factor productivity theory,using basic knowledge of statistics and economics,drawing on existing research results at home and abroad,and adopting a combination of qualitative analysis and quantitative analysis of SAS multiple stepwise regression,the changing trends of cost-benefit of mutton sheep breeding in Northwest agricultural and pastoral areas and influencing factors of production costs and production efficiency were investigated,aiming to provide reference for saving mutton sheep feeding material resources,reducing mutton sheep breeding costs,and improving mutton sheep breeding benefits. 展开更多
关键词 Lamb costs and benefits Stepwise regression Guizhou black goats Selection and breeding thinking
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部