摘要:

Box and Hill [6] recently proposed a method for using power transformation weighting in least squares analysis to account for changing variance. Such an approach can be useful when the original data are heteroscedastic but adequate weight estimates are not available, and when the original data are homoscedastic but heteroscedasticity is induced by the data analyst in linearising a nonlinear model.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489544

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

When fitting the first-degree Scheffé polynomial and the assumption of homogeneous error variance is suspect, one suggestion made in this paper is to place the design points in a symmetrical arrangement and along the component axes. For if the magnitude of the error variance (or observation variance) follows one of several conceivable symmetrical patterns, the use of the symmetrical axial designs will result in the existence of certain relationships between the parameter estimates obtained using an unweighted analysis versus using a weighted analysis. Some results which carry over to the parameter estimates in a second-degree polynomial forq= 3, 4 and 5 are presented along with two real examples.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489545

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Graphical Evaluation and Review Technique (GERT) has been applied to modeling of sampling plans and promises to be of value in encouraging statistical quality control. In this paper we analyze the dynamics of the Dodge-Romig sampling inspection plan by GERT and propose a new sampling plan which secures the advantages of both customer and producer.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489546

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The criterion for choosing which CSP-1 to employ for continuous production screening is usually the AOQL. This is based on the average fraction inspected (AFI), which has only been calculated analytically under the assumption of an infinite production run. For short production runs the AFI is higher because of the starting procedure of the plan. A formula is derived which gives a good approximation to the AFI for a finite production run.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489547

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The problem of estimating the parameters of the simple linear regression model when the samples are symmetrically trimmed or Winsorized is considered. The efficiency of the ordinary least squares estimators (OLSE) relative to the best linear unbiased estimators (O-BLUE) from trimmed, Winsorized and complete samples is discussed. The exact relative efficiencies are given for some symmetric distributions and for values of 5 ≤n≤ 20. It is found that the (OLSE) estimators based on trimmed data are almost as efficient as the (O-BLUE) estimators for a variety of distributional specifications, while Winsorizing performs rather less well in several cases and marginally better in a few. It is found that for the standard normal and the scale contaminated normal distributions, the (OLSE) from trimmed samples maintain very high efficiencies relative to the (O-BLUE). Similarly, for the Winsorized (OLSE). But as the tails of the distribution become heavier—e.g. the double exponential distribution—the loss in efficiency of the Winsorized estimators becomes larger. The trimmed (OLSE) were better for heavier-tailed distributions than the Winsorized.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489548

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

A unified approach based on the ranks of the residuals iS developed for testing and estimation in the linear model, The methods are robust and efficient relative to least squares methods. For ease of application, the strong analogy to least squares strategy is emphasized. The procedures are illustrated on examples from regression and analysis of covariance.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489549

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Both the standard jackknife and a weighted jackknife are investigated in the general linear model situation. Properties of bias reduction and standard error estimation are derived. and the weighted jackknife shown to be superior for unbalanced data. There is a preliminary discussion of robust regression fitting using jackknife pseudo-values.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489550

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The problem of testing the composite hypothesis of normality is considered for complete samples. Three related test procedures are developed. The testing procedures have their origins in an attempt to formalize the appearance of nonlinearity in probability plots. The fitting of the ordered observations is accomplished by general linear least squares using the expected values of the standard normal order statistics (snos) as plotting positions. The moments of the snos have been approximated where necessary. The test statistics are ratios involving the squares of linear combinations of order statistics and the usual quadratic estimate of the variance. The percentage points ofthe test statistics aregenerally intractable by analytical methods. However percentage points are estimated using simulation techniques. The test procedures are compared to nine other tests of the composite hypothesis of normality in an empirical power study.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489551

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

This article is concerned with estimating percentage points for the RST (R-statistic) many outlier procedure. This procedure has been introduced in [5] and a brief discussion is given in Section 1. The algorithm used to estimate the percentage points is given in Section 2. Percentage points are given for α = .10, .05, .01,N= 10(5) 20(10) 50(25) 100,k= 2:N= 20(10) 50(25) 100,k= 3;N= 20(10) 50(25) 100,k= 4. Two examples illustrating the use of the procedure are given in Section 3. Finally some potential weaknesses of the method are discussed in Section 4: namely, when the actual number of outliers in a sample is larger than the maximum number of outliers assumed by the procedure. Alternatives are proposed for possibly modifying the procedure to allow for this contingency.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489552

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Performances of two versions of a proposed weighted average for estimating the current state of a process are compared to those of two weighted averages, the BLUE and the BLE, and a geometrically weighted moving average. Contrary to some published results, the geometrically weighted moving average is found to be preferable in general to the proposed weighted average.

ISSN:0040-1706    

DOI:10.1080/00401706.1977.10489553

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor