山西省农机总动力的Usher曲线分析

Usher curve analysis of total power of agricultural machinery in shanxi province

[目的]对山西省农机总动力拥有量的发展趋势进行详细的分析并加以预测。[方法]基于Usher曲线的微分形式,求出异时参数的估计量,利用Usher曲线对1979～2015年山西省农机总动力的拥有量数据进行拟合,用平均相对误差MRE和拟合优度R^2表示拟合效果的优劣。[结果]通过R语言编程得出未知参数及异时参数的非线性最小二乘估计值,所得MRE为2.65%,R^2为0.998,2006年与2040年分别为山西农机总动力拥有量增长的最大加速点和最大减速点,预计到2020年可突破4 000万kW。[结论]Usher曲线可对山西农机总动力的拥有量进行较好的描述,并对其增长趋势进行有效的预测,为我省相关部门制定政策提供一定的依据。

[Objective]Present study was aimed to analyze and predict the developmental trend of total power of agricultural machinery in Shanxi province.[Methods]The estimation of the heterochrony parameters were obtained based on the differential form of the Usher curve which was used to fit the data of the total power of the Shanxi agricultural machinery from 1979 to 2015,and the mean relative error(MRE)and the fitting superiority were used to express the fitting effect.[Results]The calculated MRE was 2.65%,and the fitting optimization was 0.998.The maximum acceleration points and maximum deceleration points of the total power ownership of Shanxi agricultural machinery were determined to be happened in 2006 and 2040,respectively,and it was expected to exceed over 40 million kilowatts by 2020.[Conclusion]Usher curve produced a good description of the total power of Shanxi agricultural machinery,and made an effective forecast of its growth trend.It provided a solid evidence for legislative departments of our province.