摘要:

The Shewhart-CUSUM quality control scheme which combines the key features of the Shewhart and CUSUM control procedures is described and evaluated. In this scheme the CUSUM feature will quickly detect small shifts from the goal while the addition of Shewhart limits increases the speed of detecting large shifts. The combined Shewhart-CUSUM scheme has performance comparable to that of the more involved parabolic CUSUM. The Shewhart-CUSUM scheme works with only the current observations so it requires less computer storage space than parbolic CUSUM, which requires the storage of several previous observations. This becomes particularly important when many control schemes are simultaneously implemented.

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978790

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

The negative binomial distribution is frequently used as an alternative to the Poisson distribution for count data. One interpretation of the negative binomial distribution is that it is a compound Poisson distribution with means chosen at random from a gamma distribution. This appears to be a useful model for failure data, particularly for data from a number of repairable systems all of which follow a Poisson process but with different intensities. In this framework the times to failure are of importance and the distributions of these are derived for both a single system and a collection of systems. The distributions are shown to be related to Snedecor's F distribution. The usefulness of these concepts is exemplified through evaluations of reliability and spare parts requirements based on some airplane component data. Method of moments estimation of the parameters and confidence interval estimation of the average failure intensity are also mentioned.

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978791

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

The Schefféand Becker models for mixture systems present special computing problems because neither of these models contains a constant term. Scientists may find that the associated least-squares calculations are inaccurate because of computer roundoff errors or, worse yet, that the available regression program does not have the capability of fitting a zero-intercept model. It is shown that these two problems can be circumvented by dropping one of the linear terms from the model and replacing it with a constant term. The resulting intercept model produces all the coefficients, predictions and significance tests appropriate to the Schefféor Becker models. Methods for detecting roundoff error are discussed and recommendations concerning preferred computing procedures are included. Examples illustrating the effectiveness of the proposed methodology are presented.

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978792

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

A statistical methodology using ranking and selection procedures should have many useful applications for quality engineers. This consists of a body of techniques which can, for example, be used to (1) identify the best process among several, (2) identify those processes that are better than others, (3) rank completely all processes with respect to some measurable characteristic, or (4) identify those processes that are better than a control or specified standard, while, in each case controlling the probability that the identification or ranking is correct. The basic concepts underlying those procedures are introduced, the methodology is explained and numerical examples are given. The procedures frequently involve determination of the sample size required to meet specified criteria.

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978793

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Some background leading to the development of MIL-STD-1695, released by the Naval Air Systems Command on September 13, 1977, is presented. The rationale behind the selection of the particular environments to be controlled, the justification for the environmental levels invoked and current plans for additional studies of environmental controls are discussed.

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978794

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

A BASIC program is given that applies Yates' method of analyzing replicated two-level factorial experiments. Mean effects and sums of squares are printed out. User-specified mean effects can be set to zero following which expected values, residuals and the mean square for error are calculated and printed out.

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978795

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978796

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978797

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978798

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

ISSN:0022-4065    

DOI:10.1080/00224065.1982.11978799

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor