Anyone know how to generate data for arima by sas ? or seasonal arima model 主题:弱弱的问:如何在sas数据集中随机取样本?
A cohort study is a longitudinal study in which a specific population is studied over time 群体研究是在一段时间内对特定群体进行的纵向研究(随机取样) 。
The thesis task is a part of the serial number project of 500mhz random sampling wideband digital storage oscillograph , 2002 本课题是2002年的型号项目“ 500mhz随机取样宽带数字存储示波器”预研的一部分。
The game is to find a set of arrows that , when linked up end to end , leaves a gap between head and tail ( the two ends ) of 10 - 120 inch 但一组相当接近预期结果的向量,却极有可能被下一个随机取样的向量给搞砸了。
Another 25 premature infants with study group matched gestational age , weight , and apgar score , who had been previously treated at this nicu from 1990 to 1992 served as control group 另外1990年至1992年随机取样25位怀孕周数、出生体重和实验组一样的早产儿为对照组。
High - speed random sampling of high - speed digitizing storage oscilloscope is discussed in this thesis and which are mainly analysed in the time - domain and the frequency - domain 本课题研究对象是高速数字存储示波器的高速随机取样变换技术。主要从频域和时域两个方面加以分析论述。
At the other end of the spectrum , high - error - rate ( 4 percent ) random sampling of the genome has proved useful for discovery and classification of various rna and tissue types 从另一角度来看,对基因组随机取样定序,即使误差高( 4 % ) ,却对发现和区分各种rna和组织类型极为有用。
The methodological quality of included trials was generally " poor . " few trials reported methods of randomization . three trials were randomized , double blind , and placebo - controlled 很少有实验报道随机取样的方法。内含的试验方法的质量一般很弱。三种试验分别为随机取样、双盲法、安慰剂给样试验。
" the test for the methods of study of middle school students " is applied on the investigation of how the urban middle school students and rural middle school students get on with their study which is selected at random 本研究采用《中学生学习方法测验》对城市中学初中学生与农村中学初中学生的学习适应性进行随机取样调查。
This paper deals with the problem of non - uniform weed numbers obtained with all types of random sampling methods , discussing the importance of statistical control methods in herbicide efficacy evaluation and showing pertinent calculations 针对随机取样中的各样方内杂草数目不一致问题,讨论了统计控制方法在除草剂药效评价中的重要性以及计算过程。