Robust Monitoring of Contaminated Multivariate Data

The effect of parameter estimation on Phase II control chart performance in monitoring financial GARCH processes with contaminated data

The application of control charts for monitoring financial processes has received a greater focus after recent global crisis. The Generelized AutoRegressive Conditional Heteroskedasticity (GARCH) time series model is widely applied for modelling financial processes. Therefore, traditional Shewhart control chart is developed to monitor GARCH processes. There are some difficulties in financial su...

Robust Holt-Winter based control chart for monitoring autocorrelated simple linear pro les with contaminated data

Robust tools for the imperfect world

Data outliers or other data inhomogeneities lead to a violation of the assumptions of traditional statistical estimators and methods. Robust statistics offers tools that can reliably work with contaminated data. Here, outlier detection methods in low and high dimension, as well as important robust estimators and methods for multivariate data are reviewed, and the most important references to th...

Application of robust multivariate control chart with Winsorized Mean: a case study

Water pH and active ingredient concentration are two of the most important variables to consider in the manufacturing process of fungicides. If these variables do not meet the required standards, the quality of the product may be compromised and lead to poor fungicide performance when water is used as the application carrier, which is in most cases. Given the correlation between the variable...

Robust and Adaptive Filtering of Multivariate Online-Monitoring Time Series

We propose a new regression-based filter for multivariate time series that separates signals from noise and outliers in real time. The new method merges the advantageous properties of two existent filtering procedures for online-monitoring time series. Our multivariate and robust procedure yields signal estimations at the right end point of a moving time window whose width is adapted to the cur...