抽样区间可变带有警戒限的中位值控制图  

Median control chart with warning lines under variable sampling intervals

作　　者：张晓轶[1] 宋向东[1] 

机构地区：[1]燕山大学理学院,河北秦皇岛066004

出　　处：《辽宁工程技术大学学报（自然科学版）》2014年第2期276-279,共4页Journal of Liaoning Technical University (Natural Science)

基　　金：全国统计科研计划基金资助项目(2011LY064)

摘　　要：针对在统计过程中控制图出现异常时发出信号时间长短的问题,将带有警戒限的中位值控制图推广到抽样区间可变的情形,设计了可变抽样区间带有警戒限的中位值控制图(WLVSI图),利用Markov链理论推导平均链长(ARL)公式,计算发信号前的平均时间,并与常规控制图、带警戒限的中位值控制图作出比较.结果表明:控制图的抽样区间可变时,发信号前的平均时间更短,较之固定抽样区间的控制图更合理,改进后的控制图用于实际生产中可提高效率,减少不合格品数,从而降低经济损失.In order to overcome the problem of the time of signaling when the control chart is anomalous in the statistical process, this paper extended the median control chart with warning lines to the case of variable sampling intervals, and designed the median control chart with warning lines under variable sampling intervals. It calculated the average time before the control chart signaIs by using the average run length formula derived from the theory of Markov chain, and made comparison between the conventional chart and the median control chart with warning lines. The results show that the average time of signaling is shorter when the sampling intervals are variable. It is also more reasonable than the control chart with fixed sampling intervals. The improved control chart can improve the efficiency and reduce the number of defective products in actual production, thereby it reduces economic losses.

关 键 词：可变抽样区间 中位值 统计量 警戒限 控制图 平均链长 平均时间 比较分析 

分 类 号：O213.1[理学—概率论与数理统计]