An ARL-unbiased design of time-between-events control charts with runs rules

In this paper, we consider incorporating the runs rules into the cumulative quantity control (CQC) chart for monitoring time-between-events data. We propose a simple and effective procedure to design a CQC chart coupled with runs rules that can yield average run length (ARL)-unbiased performance and meet the required in-control ARL. The proposed design involves determining a relation between the upper side and lower side false alarm probabilities. A Markov chain approach is used to evaluate the ARL performance of various control schemes studied in this paper. An extensive numerical comparison shows that the proposed design approach can result in a significant reduction in ARL for detecting increases in the occurrence rate of the event in comparison with the basic CQC charts.     

The effect of autocorrelation on the retrospective X-chart

Quality control chart interpretation is usually based on the assumption that successive observations are independent over time. In this article we show the effect of autocorrelation on the retrospective Shewhart chart for individuals, often referred to as the X-chart, with the control limits based on moving ranges. It is shown that the presence of positive first lag autocorrelation results in an increased number of false alarms from the control chart. Negative first lag autocorrelation can result in unnecessarily wide control limits such that significant shifts in the process mean may go undetected. We use first-order autoregressive and first-order moving average models in our simulation of small samples of autocorrelated data.     

知识创造的SIO-IE模型——对野中郁次郎SECI模型的修正与改进

知识按照其可言说/表达程度的不同构成内隐性-外显性谱,所有的知识都可以在谱图上找到自己适当的位置,通常所说的隐性知识和显性知识分处于谱图的两端。知识创造过程可归结为共同化、融合化和操作化三个阶段的螺旋上升过程,三个阶段都存在知识的内化和外显化。外显化与内化相互依赖、相互促进,从而促使知识不断地增长,最终创造出操作知识和创新知识。     

《普度明太祖长卷图》及其第十三段回鹘蒙古文考释

《普度明太祖长卷图》（又称《噶玛巴为明太祖荐福图》）现收藏于西藏博物馆。明朝永乐五年（1407年）,西藏噶举派宗教领袖第五世活佛噶玛巴一行应明成祖朱棣的邀请抵达南京,为已故明太祖朱元璋及其皇后荐福。长卷图共49幅,22幅画的右侧有汉、波斯、傣、藏、回鹘蒙古文等五种文字的说明。该图中的回鹘蒙古文说明共22段76行,约1500个词。长卷图第十三段回鹘蒙古文考释及汉文和转写的研究有它的独特意义。     

A new double sampling control chart for monitoring process mean using auxiliary information

Statistical quality control charts have been widely accepted as a potentially powerful process monitoring tool because of their excellent speed in tracking shifts in the underlying process parameter(s). In recent studies, auxiliary-information-based (AIB) control charts have shown superior run length performances than those constructed without using it. In this paper, a new double sampling (DS) control chart is constructed whose plotting-statistics requires information on the study variable and on any correlated auxiliary variable for efficiently monitoring the process mean, namely AIB DS chart. The AIB DS chart also encompasses the classical DS chart. We discuss in detail the construction, optimal design, run length profiles, and the performance evaluations of the proposed chart. It turns out that the AIB DS chart performs uniformly better than the DS chart when detecting different kinds of shifts in the process mean. It is also more sensitive than the classical synthetic and AIB synthetic charts when detecting a particular shift in the process mean. Moreover, with some realistic beliefs, the proposed chart outperforms the exponentially weighted moving average chart. An illustrative example is also presented to explain the working and implementation of the proposed chart.     

基于协方差阵特征结构的新型控制图研究

本文在深入分析现行广义方差类的统计控制图存在的统计监控缺陷的基础上,提出了对多变量过程的协方差阵的特征向量张成的坐标系的一致性进行统计监控的C控制图,以及对特征值构成的椭球体的相似性进行监控的S控制图,有效地提高了对多变量过程的协方差阵的异常变动的统计监控能力。仿真表明,联合使用C控制图、S控制图及常规均值T²控制图,能够实现对多变量过程的协方差阵与均值的系统监控,显著改善监控效率。     

过程控制图在股票收益波动分析中的应用研究

应用AR型残差控制图解决过程自相关问题;用受控过程的条件标准差替代无条件标准差,构造控制图的控制线,解决过程波动簇聚问题.在实证中,以上证50指数中股票的周收益序列为样本过程,根据其统计性质将其分为四类,并分别举例、选择适当的控制图加以监控.然后,对控制图识别出的异常点举例进行验证、分析,以评价控制图应用于股票收益序列监控的有效性.     

Combined double sampling and variable sampling interval np chart

A combined double sampling and variable sampling interval (DSVSI) np chart is investigated in this study. The optimal design of the DSVSI np chart is based on minimizing the out-of-control average time to signal. From the numerical results, the DSVSI np chart performs reasonably well in comparison with the standard np chart, double sampling np chart, synthetic double sampling np chart, and other existing np type control charts for detecting increases in the process of fraction non conforming, based on the zero-state case. An example is provided to illustrate the application of the DSVSI np chart.