Asili Sahar, Rezaei Sadegh, Najjar Lotfollah
Department of Statistics, Amirkabir University of Technology, Tehran 15875-4413, Iran.
College of Information Science Technology, University of Nebraska-Omaha, Omaha, NE 68182, USA.
Biomed Res Int. 2014;2014:790294. doi: 10.1155/2014/790294. Epub 2014 May 21.
Fertility rate is one of the most important global indexes. Past researchers found models which fit to age-specific fertility rates. For example, mixture probability density functions have been proposed for situations with bi-modal fertility patterns. This model is less useful for unimodal age-specific fertility rate patterns, so a model based on skew-symmetric (skew-normal) pdf was proposed by Mazzuco and Scarpa (2011) which was flexible for unimodal and bimodal fertility patterns. In this paper, we introduce skew-logistic probability density function as a better model: its residuals are less than those of the skew-normal model and it can more precisely estimate the parameters of the model.
生育率是最重要的全球指标之一。过去的研究人员发现了适用于特定年龄生育率的模型。例如，对于具有双峰生育模式的情况，已经提出了混合概率密度函数。该模型对于单峰特定年龄生育率模式不太有用，因此马祖科和斯卡帕（2011年）提出了一种基于偏对称（偏正态）概率密度函数的模型，该模型对于单峰和双峰生育模式都具有灵活性。在本文中，我们引入偏逻辑斯蒂概率密度函数作为一个更好的模型：它的残差小于偏正态模型的残差，并且它可以更精确地估计模型参数。
