In some statistical process monitoring applications, quality of a process or product is described by more than one ordinal factors called ordinal multivariate process. To show the relationship between these factors, an ordinal contingency table is used and modeled with ordinal log-linear model. In this paper, a new control charts based on ordinal-normal statistic is developed to monitor the ord...

The modified exponentially weighted moving-average (modified EWMA) control chart is an improvement on the traditional EWMA chart. Herein, we provide more details about using various values of additional design parameter for detecting small-to-moderate shifts in process mean autoregressive fractionally integrated (ARFI(p, d)) with exponential white noise running thereon. statistical performances...

In statistical process control, the primary method used to monitor the number of nonconformities is the c-chart. The conventional c-chart is based on the assumption that the occurrence of nonconformities in samples is well modeled by a Poisson distribution. When the Poisson assumption is not met, the X-chart (individuals chart) is often used as an alternative charting scheme in practice. In thi...

Statistical process control (SPC) is a method for improving the quality o f products. Control charting plays a most important role in SPC. SPC control charts arc used for monitoring and detecting unnatural process behaviour. Unnatural patterns in control charts indicate unnatural causes for variations. Control chart pattern recognition is therefore important in SPC. Past research shows that alt...

This paper proposes three synthetic-type control charts to monitor the mean time-between-events of a homogenous Poisson process. The first proposed chart combines an Erlang (cumulative time between events, Tr ) chart and a conforming run length (CRL) chart, denoted as Synth-Tr chart. The second proposed chart combines an exponential (or T) chart and a group conforming run length (GCRL) chart, d...

Introduction.-For the purpose of studying the interpretations which the recently acquired knowledge of the structure of atoms might afford as to tendencies of elements to form ions and to exist in definite valence states, the authors compiled from spectroscopic publications of the last three years the values of the energies attending the removal of the various electrons from the outer shells of...

In this paper, a remedial measure is first proposed to eliminate the effect of autocorrelation in phase-ІІ monitoring of autocorrelated polynomial profiles, where there is a first order autoregressive (AR(1)) relation between the error terms in each profile. Then, a control chart based on the generalized linear test (GLT) is proposed to monitor the coefficients of polynomial profiles and an R-c...

BACKGROUND Contrast sensitivity measurement in UK clinical practice is most commonly performed with the Pelli-Robson chart. AIMS To compare the repeatability of two new contrast sensitivity charts and to measure their agreement with the Pelli-Robson charts. METHOD Contrast sensitivity was measured monocularly using two versions of the Mars letter contrast sensitivity chart, two presentation...