In this paper, we study the classical problem of estimating the proportion of a finite population. First, we consider a fixed sample size method and derive an explicit sample size formula which ensures a mixed criterion of absolute and relative errors. Second, we consider an inverse sampling scheme such that the sampling is continue until the number of units having a certain attribute reaches a...

It is a ubiquitous problem to estimate the means of bounded random variables. Specially, the problem of estimating the probability of an event can be formulated as the estimation of the mean of a Bernoulli variable. Moreover, in many applications, one needs to estimate a quantity μ which can be bounded in [0, 1] after proper operations of scaling and translation. A typical approach is to design...

In the context of economic design, a two-stage model is proposed that utilizes continuously variable sampling intervals. Specifically, each successive sampling interval is determined by the extremity of the latest sample. Modeling the situation as a Markov chain, the hourly cost is developed for any arbitrary set of design parameters. This proposed approach is found to be more economically desi...

This paper proposes a new computational scheme for approximating variable-order fractional integral operators by means of finite element scheme. This strategy is extended to approximate the solution of a class of variable-order fractional nonlinear systems with time-delay. Numerical simulations are analyzed in the perspective of the mean absolute error and experimental convergence order. To ill...

The principal function of a control chart is to help management distinguish different sources of variation in a process. Control charts are widely used as a graphical tool to monitor a process in order to improve the quality of the product. Chen and Hsieh (2007) have designed a T2 control chart using a Variable Sampling Size and Control limits (V SSC) scheme. They have shown that using the V SSC...

The voltage sag detection algorithm and control algorithm synthesis of the dynamic voltage restorer (DVR) are proposed. The double synchronous reference frame phase-locked loop (DSRF-PLL) is applied for the voltage sag detection, which is able to calculate the phase angle of the positive-sequence fundamental component of grid voltages even under unbalanced and distorted grid voltages. The effec...

Statistical Process Control (SPC) charts are widely used in manufacturing industry for monitoring the performance of sequential production processes over time. A common practice using a control chart is to first collect samples and take measurements certain quality variables from them at equally-spaced sampling times, then make decisions about process status by based on observed data. In some a...

Online process control consists of inspecting a single item at every mth items produced, where m is an integer greater than two. Based on the results of the inspection, one decides if the process is in-control (the fraction of conforming item is p1—state I) or out-of-control (the fraction of conforming item is p2—state II). If the inspected item is non-conforming, the process is designated as o...

Based on the technological process of obtaining tea products, factors determining its quality are considered. The analysis these and their classification. optimization labor costs time to perform control raw materials using methods probability theory. a simple discrete Markov chain, proposed system selective products by variable samples.