摘要:

When a two-dimensional map contains points that appear to be scattered somewhat at random, a question that often arises is whether groups of points that appear to cluster are merely exhibiting ordinary behavior that one can expect with any random distribution of points, or whether the clusters are too pronounced to be attributable to chance alone. In this paper a method for detecting clusters along a straight line.is applied to the two-dimensional map of bismuth-214 anomalies observed as part of the National Uranium Resource Evaluation Program in the Lubbock, Texas region. Some exact probabilities associated with this method are computed and compared with two approximate methods. The two methods for approximating probabilities work well in the cases examined, and can be used when it is prohibitive to obtain the exact probabilities.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489770

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Permutation tests based on certain ratio statistics have been used (a) in the analysis of rainfall stimulation experiments and (b) in simulation studies aimed at providing guidance in the planning of such experiments. The paper presents asymptotic approximations to the permutation distributions of these statistics, and also to their power functions under a simple multiplicative model for the seeding effect. Simulation results are presented for comparison with the theoretical approximations.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489771

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Care is required when analysing multiple response data if misleading results are to be avoided. Boxet al. [4] have warned of errors in analysis resulting from linear relationships among the response data, and have provided a detection procedure. This is effective for most situations; however, we have encountered two cases that require additional consideration. This paper extends the work of Boxet al. to include these cases. The key issue is the detection of singularities in the multiresponse dispersion matrix, and a procedure for this is presented. The situation is also discussed in which linear dependencies in the data may be ignored to advantage. Illustrations are from chemical kinetics investigations.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489772

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An efficient implicit enumeration algorithm is proposed for the problem of selecting subsets of predictor variables in a multiple linear regression model using the minimum sum of weighted absolute errors (MSWAE) criterion. The proposed algorithm is illustrated with an example. Computational experience shows that the proposed algorithm is superior to the currently available algorithm in terms of computation time and the number of iterations required to solve a problem.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489773

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The modifiedksplines are introduced. A simple linear model results from applying a variational principle to a modified 3-spline approximation of Φ′ on [1,2]. An approximation of Φ is obtained analytically by integration. The coefficients needed to use this approximate method are tabulated.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489774

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Based on Pitman asymptotic relative efficiency and Monte Carlo studies of power functions, Shorack [29] concluded in the independent and identically distributed (i.i.d.) case that the most satisfactory tests for scale changes were the Box-Andersen test and the jack knife. Analogs of these two procedures are shown to have identical asymptotic properties when the observations follow a correctly identified autoregressive process. A Monte Carlo study indicates that the performance of these robust procedures is roughly the same as in the i.i.d. case. The difference between the two robust procedures seems slight. The Box-Andersen procedure does a better job of maintaining the stated significance level but it lags slightly behind the jack knife in power.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489775

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The main purpose of this paper is to demonstrate the usefulness of a simplex search procedure for the problem of augmenting a given experimental design to “optimize” it with respect to some criterion. In particular, the paper demonstrates the ability of the simplex search procedure to addmpoints simultaneously to an initial design in order to maximize |X′X| In the process, the paper presents a method for improving the Nelder-Mead simplex search procedure.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489776

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A fractional factorial design is of resolution IV if all main effects are estimable in the presence of two-factor interactions. For thesnfactorial experiment such a design requires at leastN=s[(s– I)n– (s– 2)] runs. In this paper a series of resolution IV designs are given for the s” factorial,s=pαwherepis prime, inN=s(s– I)nruns. A special case of the construction method produces a series of generalized foldover designs for thesnexperiment,s≥ 3 andn≥ 3, inN=s(s– I)n+sruns. These foldover designs permit estimation of the general mean in addition to all main effects and providesdegrees of freedom for estimating error. A section on analysis is included.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489777

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Bishop and Dudewicz [2] gave a two-stage procedure for testing hypotheses in analvsis of variance models with unequal variances. This paper presents multiple-comparison procedures which may be used to follow up those tests. They are similar in form to the Tukey and Scheffe type multiple-comparison procedures. The confidence intervals are of fixed-length and have associated confidence coefficients which are independent of the unknown variances.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489778

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

This paper is concerned with the treatment of residuals associated with principal component analysis. These residuals are the difference between the original observations and the predictions of them using less than a full set of principal components. Specifically, procedures are proposed for testing the residuals associated with a single observation vector and for an overall test for a group of observations. In this development, it is assumed that the underlying covariance matrix is known; this is reasonable for many quality control applications where the proposed procedures may be quite useful in detecting outliers in the data. A numerical example is included.

ISSN:0040-1706    

DOI:10.1080/00401706.1979.10489779

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor