在固定时间抽样的可变抽样区间控制图
Variable Sampling Interval Control Charts with Sampling at Fixed Times
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摘要: 本文根据Reynolds在固定时间抽样的可变抽样区间(VSIFT)的x控制图1的模型设计中位值\widetildex和极差R图.规定样本在相等间隔的固定时间点抽取,当过程有变化的迹象时,允许在两个固定时间之间抽取附加样本.本文计算了VSIFT\widetildex图和R图及联合\widetildex-R图的发信号前的平均时间,并同固定抽样区间(FSI)的常规\widetildex和,i>R图作比较.所设计的 VSIFT\widetildex和R图能缩短过程失控时间从而减少不合格品数。Abstract: This paper proposes median and range variable sampling interval control charts with sampling at fixed times based on Reynolds model of x control chart, working out the average time to signal for \widetildex and R charts and combined \widetildex and R charts under variable sampling intervals with sampling at fixed times. In the meantime, the author compares these charts with the fixed sampling intervals \widetildex and R charts.