Standard control charts are often based on the assumption that the observations follow a specific parametric distribution, such as the normal. In many applications we do not have enough information to make this assumption and in such situations, development and application of control charts that do not depend on a particular distributional assumption is desirable. Nonparametric or distribution-...

This paper considers statistical process control (SPC) of univariate processes when the parametric form of the process distribution is unavailable. Most existing SPC procedures are based on the assumption that a parametric form (e.g., normal) of the process distribution can be specified beforehand. In the literature, it has been demonstrated that their performance is unreliable in cases when th...

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...

Recurrent event time data are common in biomedical follow-up studies, in which a study subject may experience repeated occurrences of an event of interest. In this paper, we evaluate two popular nonparametric tests for recurrent event time data in terms of their relative efficiency. One is the log-rank test for classical survival data and the other a more recently developed nonparametric test b...

a manufacturing process cannot be released to production until it has been proven to be stable. also, we cannot begin to talk about process capability until we have demonstrated stability in our process. this means that the process variation is the result of random causes only and all assignable or special causes have been removed. in complicated manufacturing processes, such as drilling proces...

Background: Despite many studies showing a correlation between fast food consumption and non-alcoholic fatty liver disease (NAFLD) known as the silent death, few studies have investigated the effects of different types of fast foods on this disease. This research aimed to evaluate the effect of consuming different types of fast foods on non-alcoholic fatty liver disease. Materials and Methods:...

In this paper we have considered a non convex optimal control problem and presented the weak, strong and converse duality theorems. The optimality conditions and duality theorems for fractional generalized minimax programming problem are established. With a parametric approach, the functions are assumed to be pseudo-invex and v-invex.

The effectiveness of norm-based control methodologies heavily relies on the quality of the model that describes the dynamic behavior of the plant. In practical applications, the requirement to accurately describe the system at hand often results in high-order plant-models. On the other hand, low-order models are desired to end-up with low-order controllers that reduce implementational costs. Th...

This paper proposes a simple and improved nonparametric unit–root test. An asymptotic distribution of the proposed test is established. Finite sample comparisons with an existing nonparametric test are discussed. Some issues about possible extensions are outlined.