受DeshpandeandPrabhuAjgaonkar(1982)设计的思想启发,本文给出了一种新的n=2时的严格πps抽样设计.当辅助变量值满足Xi/X〈1/2时,提出的新设计既容易实施,又容易计算一阶和二阶包含概率.同时,可以得到Horvitz-Thompson估计量的一个非负的方差估计.通过数值比较提出设计和经典πps抽样设计,说明提出方法具有潜在应用价值.
According to the design idea presented by Deshpande and prabhu (1982) ,this study pro- duces a new strict πps sampling design with sample size n= 2. When the value of auxiliary variables meet Xi/X〈l/2,the proposed design not only is implemented easily but also its first-order inclusion and second-order inclusion can accurately be calculated. Meanwhile,we provide a non-negative variance estimator of the Horvitz Thompson estimator. Some numerical data is used to compare the precision of the proposed design and classic design. The result shows that the proposed strict πps sampling design has potential applications.