Step-down testing procedures for the Hotelling T2 problem are considered. We show that the step-down procedure proposed by S.N. Roy, R.E. Bargmann, and J. Roy is inadmissibleamonginvariantprocedures (for a suitable invariance group) in many situatiqns, includiItgallthosefor which more than two steps are contemplated. We also show that in most cases, the power of the step-down procedure decrease...

This paper suggests two directional multivariate tests that aim at establishing superiority of a treatment over a control in at least one of several endpoints that are assumed to have a multivariate normal distribution. One of these tests is a one-sided, scale-invariant version of the classical Hotelling T²-test. The other is based on a summary score with weights derived from the data. Both tes...

Hotelling T control chart is one of the most important chart used to statistical quality control in the manufacture processes. However, this chart is sensitive to the non normal data and therefore, must be modified to improve its behavior with this kind of data. In this paper, we propose two new alternatives charts based on change the usual mean and covariance estimator by robust location and s...

Multivariate quality control charts show some advantages to monitor several variables in comparison with the simultaneous use of univariate charts, nevertheless, there are some disadvantages. The main problem is how to interpret the out-ofcontrol signal of a multivariate chart. For example, in the case of control charts designed to monitor the mean vector, the chart signals showing that it must...

Cycle-based signals are generally obtained through the automatic sensing of critical process variables during each repetitive operation cycle of a manufacturing process, and they thus contain a significant amount of information about the process condition. Increasing attention has been paid recently to the problem of effectively monitoring these signals as an aid to the detection of process cha...

Bayesian model or Beta-binomial conjugate using Bayesian sequential estimation method to estimate the proportion of different age groups is compared with the conventional multivariate control chart method. The parameters for the techniques were derived and applied. The result shows that the patients between the ages of 15-44 in 2009 and 44-64 and 64 and above in 2011 are out of control. This im...

In many industrial and non-industrial applications the quality of a process or product is characterized by a relationship between a response variable and one or more explanatory variables. This relationship is referred to as profile. In the past decade, profile monitoring has been extensively studied under the normal response variable, but it has paid a little attention to the profile with the ...

in some statistical process control applications, the quality of the product is characterized by thecombination of both correlated variable and attributes quality characteristics. in this paper, we propose anovel control scheme based on the combination of two multi-layer perceptron neural networks forsimultaneous monitoring of mean vector as well as the covariance matrix in multivariate-attribu...

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...

The multi-chart consists of several CUSUM or EWMA charts with different reference values that are used simultaneously to detect anticipated process changes. We not only prove that the chart can quickly achieve the asymptotic optimal bound, but also give an integral equation to determine the reference values to arrive at optimality. Simulation results are used to verify the theoretical optimal p...