Control charts are powerful tools to monitor quality characteristics of services or production processes. However, in some processes, the performance of process or product cannot be controlled by monitoring a characteristic; instead, they require to be controlled by a function that usually refers as a profile. This study suggests employing exponentially weighted moving average (EWMA) and range ...

Control chart techniques have been widely used in industries to monitor a process in quality improvement. Whenever we deal with variables data, we usually employ a combination of X-bar chart and R chart (or S chart) to monitor both the center and the spread of the process. In this paper, we propose a simple alternative, that is, we design a single chart to monitor both the center and the spread...

purpose : contrast sensitivity (cs) evaluation by sv–1000e chart in all spatial frequencies after micro incision cataract surgery (mics) and its comparison between two thin lenses after optical correction in natural and glare conditions methods : in this cross sectional study, 100 eyes having mics with dodick arc phacolaser system were evaluated. 50 thinoptx lenses and 50 acrismart lenses were ...

The purpose of this article is to evaluate the application of forecasting models along with the use of residual control charts to assess production processes whose samples have autocorrelation characteristics. The main objective is to determine the efficiency of control charts for individual observations (CCIO) and exponentially weighted moving average (EWMA) charts when they are applied to res...

abstract. in recent years several studies have shown that  control charts with adaptive schemes or double sampling plans detect both small and moderate shifts in the process mean more quickly than the traditional shewhart  chart. in the classical double sampling  chart, the difference between two points were placed in the central region of first stage was not considered. in this study, a new co...

Weather condition is one of the much effective factors in the principle of architecture and urbanization. So in this research long-term trend of effective climate elements in architecture of Darab city including mean of minimum temperature, temperature mean, mean of maximum temperature, minimum relative humidity, maximum relative humidity, relative humidity mean, wind speed and sun hours in mon...

in this paper, drift change point estimation in the mean of polynomial profiles is considered. for this purpose, the proposed change point estimator is computed using maximum likelihood approach. performance of the proposed estimator is evaluated using monte carlo simulations when t2 control chart issues an out-of-control signal. simulation results show that the performance of the proposed esti...

Adaptive Cumulative SUM charts (ACUSUM) have been recently proposed for providing an overall good detection over a range of mean shift sizes. The basic idea of the ACUSUM chart is to first adaptively update the reference value based on an Exponentially Weighted Moving Average (EWMA) estimate and then to assign a weight on it using a certain type of weighting function. A linear weighting functio...

Abstract. In cricket the performance of the players whether bowler or batsman is being analyzed with the help of very simple statistical tools. Mostly average scores, strike rate, average runs per wicket are being used. The main idea of this research study is to give the application of quality control charts in evaluating the performance of the players. We have made the comparative study of the...

PURPOSE To compare the visual responses of post refractive surgery's patients using Early Treatment Diabetic Retinopathy Study Chart (ETDRS) and E-chart with and without color filters. METHODS The uncorrected Logarithm of the Minimum Angle of Resolution Visual Acuity (LogMAR VA) of 70 patients with a mean age of 26.2 ± 3.76 years (from 19 to 34 years) who had undergone Photorefractive Keratec...