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...

Statistical process control methods for monitoring processes with univariate ormultivariate measurements are used widely when the quality variables fit to known probabilitydistributions. Some processes, however, are better characterized by a profile or a function of qualityvariables. For each profile, it is assumed that a collection of data on the response variable along withthe values of the c...

Multivariate control charts such as Hotelling`s T^ 2 and X^ 2 are commonly used for monitoring several related quality characteristics. These control charts use correlation structure that exists between quality characteristics in an attempt to improve monitoring. The purpose of this article is to discuss some issues related to the G chart proposed by Levinson et al. [9] for detecting shifts in ...

Hotelling T 2 control chart not only reflects the correla-tions between different quality characteristics but also has good efficiency on monitoring multivariate in production process. A new alternative was constructed after original products data are processed by using exponentially weighted moving average for cumulating failure effects because is ineffective detecting minimal mean deviations....

The retrospective chart review of 110 patients with T2 supraglottic cancer who underwent radiotherapy was performed to correlate tumor volume with other prognostic factors and to analyze its impact on treatment results. Patients with involved nodes, poor histopathological tumor differentiation, or hemoglobin concentration ≤ 14.3 g/dl had significantly larger tumors. Patients with large tumors h...

Control charts are extensively used in manufacturing contexts to monitor production processes. This article illustrates economical design of a variable sample size and control limit Hotelling’s T2 control chart based on a novel cost model when occurrence times of the assignable causes are exponentially distributed. The proposed nonlinear cost model is an extension of Duncan’s (J Am Stat ...

Introduction: The area at risk (AAR) of infarction is the hypoperfused myocardial bed during coronary occlusion. The edematous AAR can be delineated in-vivo by T2 MRI and can be used in conjunction with delayed contrast enhancement to calculate myocardial salvage. T1 MRI has been recently used to image the edema associated with acute myocardial infarction. Objectives: We hypothesized that, due ...

While researchers and practitioners may seamlessly develop methods of detecting outliers in control charts under a univariate setup, screening multivariate pose serious challenges. In this study, we propose robust chart based on the Stahel-Donoho estimator (SDRE), whilst process parameters are estimated from phase-I. Through intensive Monte-Carlo simulation, study presents how estimation presen...

Mortality modelling is a practical method for the government and various fields to obtain picture of mortality up specific age particular year. However, some information on phenomenon may remain in residual vector be unrevealed from models. We handle this issue by employing multivariate control chart discover substantial cohort changes behavior that models still need address. The Hotelling T2 a...