Sampling intervals, not numbers, without replacement.
采样间隔，不是数字，无需更换。
2
Under simple random sampling scheme without replacement and unknown proportion of population possessing neutral attribute, the optimal allocation of sizes of two sub-samples is given.
对简单随机不放回抽样，在总体非敏感属性个体比例未知的情况下，给出了两个子样本容量的最优配置。
3
This paper introduced several methods about the concrete strength inspection: the sampling method given by the present specification; simple random sampling without replacement; stratified sampling.