摘要:

We consider generalized linear regression with many highly correlated regressors—for instance, digitized points of a curve on a spatial or temporal domain. We refer to this setting assignal regression, which requires severe regularization because the number of regressors is large, often exceeding the number of observations. We solve collinearity by forcing the coefficient vector to be smooth on the same domain. Dimension reduction is achieved by projecting the signal coefficient vector onto a moderate number ofBsplines. A difference penalty between theB-spline coefficients further increases smoothness-the P-spline framework of Eilers and Marx. The procedure is regulated by a penalty parameter chosen using information criteria or cross-validation.

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485591

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The purpose of this article is to present a case study of integrating statistical process control (SPC) and engineering process control (EPC) in an industrial polymerization process. We develop and compare the effectiveness of several regulation strategies to reduce polymer viscosity deviations from target. Controllers are derived using the constrained minimum variance criterion. Robustness properties and stability conditions of the controllers are discussed. The performance and the adequacy of the regulation schemes in a simulation of realistic assignable causes affecting the process are studied. In this context the benefits of implementing an integrated EPC/SPC system are compared with those of using an EPC system alone.

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485592

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The zero-inflated Poisson (ZIP) distribution has been shown to be useful for modeling outcomes of manufacturing processes producing numerous defect-free products. When there are several types of defects, the multivariate ZIP (MZIP) model can be useful to detect specific process equipment problems and to reduce multiple types of defects simultaneously. This article proposes types of MZIP models and investigates distributional properties of an MZIP model. Finite-sample simulation studies show that, compared to the method of moments, the maximum likelihood method has smaller bias and variance, as well as more accurate coverage probability in estimating model parameters and zero-defect probability. Real-life examples from a major electronic equipment manufacturer illustrate how the proposed procedures are useful in a manufacturing environment for equipment-fault detection and for covariate effect studies.

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485593

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A new method for sensitivity analysis (SA) of model output is introduced. It is based on the Fourier amplitude sensitivity test (FAST) and allows the computation of the total contribution of each input factor to the output's variance. The term “total” here means that the factor's main effect, as well as all the interaction terms involving that factor, are included. Although computationally different, the very same measure of sensitivity is offered by the indices of Sobol'. The main advantages of the extended FAST are its robustness, especially at low sample size, and its computational efficiency. The computational aspects of the extended FAST are described. These include (1) the definition of new sets of parametric equations for the search-curve exploring the input space, (2) the selection of frequencies for the parametric equations, and (3) the procedure adopted to estimate the total contributions. We also address the limitations of other global SA methods and suggest that the total-effect indices are ideally suited to perform a global, quantitative, model-independent sensitivity analysis.

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485594

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Compound orthogonal arrays have recently been introduced as an alternative to Taguchi's direct product arrays for studying location and dispersion effects simultaneously. In this article, we provide a catalog of two-level compound orthogonal arrays for parameters of most practical interest. The arrays presented possess the maximum possible strength for given numbers of factors and runs. Simple methods to obtain these arrays, using defining contrasts, are also presented.

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485595

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

It is often impractical to perform the experimental runs of a fractional factorial in a completely random order, In these cases, restrictions on the randomization of the experimental trials are imposed and the design is said to have a split-plot structure. We rank these fractional factorial split-plot designs similarly to fractional factorials using the aberration criterion to find the minimum-aberration design. We introduce an algorithm that constructs the set of all nonisomorphic two-level fractional factorial split-plot designs more efficiently than existing methods. The algorithm can be easily modified to efficiently produce sets of all nonisomorphic fractional factorial designs, fractional factorial designs in which the number of levels is a power of a prime, and fractional factorial split-plot designs in which the number of levels is a power of a prime.

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485596

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485597

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485599

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485600

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1999.10485602

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor