例句與造句

1. Simple sampling without replacement
   簡(jiǎn)單不重復(fù)抽樣
2. First , this paper gives an introduction of some methods of unequal probability sampling , their estimators and variance estimators , including sampling with pps with replacement , methods of sampling without replacement suggested by brewer , durbin , sampford , des raj , murthy , rao - hartley - cochran . then , at the basis of rao and bayless ' s study , we consider that population can be splited two random subpopulations , which are respectively drawn from different infinite super - populations , and compare the stabilities of estimators of the methods that given above . we find that the minor difference between two super - populations has great effect on the efficiency of the estimators for the population with moderately large coefficient of variation ( c . v . )
   本文首先從理論上介紹了若干種不等概率抽樣方法，它們的估計(jì)量、估計(jì)量的方差及其估計(jì)，其中包括有放回ppz及pps抽樣，不放回不等概率抽樣中的brewer 、 durbin 、 sampford 、 desraj ， murthy 、 rao - hartley - cochran等人的方法；其次，在rao和bayless兩人就樣本單元數(shù)n = 2的情形對(duì)上述抽樣方法進(jìn)行比較的基礎(chǔ)上，將總體隨機(jī)地分成兩個(gè)子總體，視每個(gè)子總體取自不同的線性超總體，在文中，我們利用計(jì)算機(jī)實(shí)現(xiàn)隨機(jī)分組，并通過(guò)畫圖比較各方法估計(jì)量的穩(wěn)定性，結(jié)果表明，對(duì)變異系數(shù)c . v . ( x )較大的總體而言，兩個(gè)超總體之間的微小差異將對(duì)估計(jì)量的穩(wěn)定性產(chǎn)生很大的影響，從而說(shuō)明rao和bayless的比較結(jié)果還不夠完善。
3. It's difficult to find sampling without replacement in a sentence. 用sampling without replacement造句挺難的