Search Results - isPartOf:"Economic Quality Control"

Improving the Variability Function in Case of a Uni-Modal Probability Distribution

Schelz F.; Sans W.; v. Collani E. - In: Economic Quality Control 22 (2007) 1, pp. 19-39

Quality Control 20: 121-142, 2005) and to the case of monotonic probability distributions by Sans et al. (Economic Quality … Bernoulli Space . Subsequently, this method has been applied to the case of uniform distributions by Sans et al. (Economic … Control 20: 121-142, 2005). In this paper the method is extended to the important case of the family of uni-modal probability …

Persistent link: https://www.econbiz.de/10011015815

A Bayesian Approach to Parallel Stress-Strength Models

Mónica, Durán; Alexis, Peña; Salinas Víctor H. - In: Economic Quality Control 22 (2007) 1, pp. 71-85

This work presents a Bayesian approach for estimating the reliability of a parallel multi-component system. It is assumed that the strengths of the components are independent random variables, which are subjected to a common stress with the same distribution. It is supposed that the failure...

Persistent link: https://www.econbiz.de/10011015825

A Note on the Moments of Random Variables

Surath, Sen; Elart, von Collani - In: Economic Quality Control 22 (2007) 2, pp. 223-246

Any random variable X describing a real phenomenon has necessarily a bounded range of variability implying that the values of the moments determine the probability distribution uniquely. In fact, the range of variability of a random variable restricts the range of the first moment; the value of...

Persistent link: https://www.econbiz.de/10011015835

Point and Interval Estimation for the Lifetime Distribution of a k-Unit Parallel System Based on Progressively Type-II Censored Data

Biswabrata, Pradhan - In: Economic Quality Control 22 (2007) 2, pp. 175-186

This work considers point and interval estimation for the lifetime distribution of a k-unit parallel system assuming exponential distribution for the components lifetime. The parameter of the distribution is estimated by the maximum likelihood method based on samples which are progressively...

Persistent link: https://www.econbiz.de/10011015860

New Results in Economic Statistical Quality Control

Rodrigues, Dias J. - In: Economic Quality Control 22 (2007) 1, pp. 41-54

In previous papers, a new adaptive sampling method was presented for application in the economic statistical control context. By means of an economic model, an optimal solution can be defined. The results obtained previously indicate that the approach might be more useful than both the...

Persistent link: https://www.econbiz.de/10011015872

Bivariate Density Classification by the Geometry of the Marginals

Mariela, Fernández; Nikolai, Kolev - In: Economic Quality Control 22 (2007) 1, pp. 3-18

In this work we propose a representation of a bivariate density corresponding to the given geometrical behavior of the marginals. A continuous density with compact support can be approximated by the exponential of an infinite polynomial. We find intervals for the possible values of its...

Persistent link: https://www.econbiz.de/10011015879

Reliability Computation of Moranda's Geometric Software Reliability Model

Vasanthi T.; Arulmozhi G. - In: Economic Quality Control 22 (2007) 2, pp. 261-272

The Jelinski-Moranda (JM) model for software failures was one of the first models used for analyzing software reliability. Later Moranda proposed a modification of the JM model, labeled Geometric de-Eutrophication model. In the Moranda Geometric de-Eutrophication model, N(t) is defined as the...

Persistent link: https://www.econbiz.de/10011015884

Approximating Reliability of a System with Doubly Bounded Performance Functions

Ahmadi, Javid Amir; Saralees, Nadarajah - In: Economic Quality Control 21 (2006) 2, pp. 243-250

The purpose of this paper is to derive an approximation of the reliability of a system with doubly bounded performance functions. The problem is illustrated through the probability of an n dimensional hyper cube of the multivariate normal distribution. An approximation method is presented to...

Persistent link: https://www.econbiz.de/10010736088

A Note on Run Length Variability Reduction for EWMA Charting

Govindaraju K.; Lingyun, Zhang - In: Economic Quality Control 21 (2006) 2, pp. 171-181

The reduction of run length variability has received little attention in the statistical process control literature. This note proposes a modification of the signal rule for the EWMA control chart resulting in a reasonable reduction of run length variability.

Persistent link: https://www.econbiz.de/10010736089

Probability Weighted Moments Approach to Quality Control Charts

Faqir, Muhammad; Muhammad, Riaz - In: Economic Quality Control 21 (2006) 2, pp. 251-260

A new control chart namely Spw -Chart for monitoring the changes in the process variability is proposed and is based on Probability Weighted Moments (PWMs) and assuming that the quality characteristic follows a normal distribution. The coefficients r 2 and r 3 (similar as the d 2 and d 3...

Persistent link: https://www.econbiz.de/10010736101