摘要:

AbstractIn this tutorial we first illustrate the effect of outliers on classical statistics such as the sample average. This motivates the use of robust techniques. For univariate data the sample median is a robust estimator of location, and the dispersion can also be estimated robustly. The resulting ‘z‐scores’ are well suited to detect outliers. The sample median can be generalized to very large data sets, which is useful for robust ‘averaging’ of curves or images. For multivariate data a robust regression procedure is described. Its standardized residuals allow us to identify the outliers. Finally, a survey of related approaches is given. (This review overlaps with earlier work by the same author, which appeared e

ISSN:0886-9383    

DOI:10.1002/cem.1180050103

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe use of Wronskian determinants in the study of multicomponent systems is proposed. The general theory is presented and applied to the spectrophotometric determination of the number of linearly independent components–absorbers. A detailed study of a two‐component system is presented and analysed. Numerical methods for smoothing and differentiation of digitized spectra via cubic splines are u

ISSN:0886-9383    

DOI:10.1002/cem.1180050104

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractGeneralized simulated annealing (GSA) is an optimization procedure for locating the global optimum (maximum or minimum) of multidimenisonal continuous functions. GSA has been modified for optimization of discrete functions. Selection of calibration samples from an existing set defines discrete optimization and GSA is used to select optimal sets of calibration samples for specific analysis samples. The procedure is applied to near‐infrared spectra. When compared to using the complete set of 37 calibration samples, concentration prediction errors were reduced 50%–100% by using select sets of two to seven calibration samples. Additionally, GSA was able to improve a poorly designed experiment. GSA devised augmented experimental designs such that the overall experimental design (original plus augmented) was more orthogonal than the origi

ISSN:0886-9383    

DOI:10.1002/cem.1180050105

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe topic of the present paper is the splitting of calibration data into subgroups with improved linearity in each group. The method proposed is based on a criterion which is a weighted average of a Mahalanobis distance and a squared regression residual. The algorithm used to find the solution is based on fuzzy clustering. Two examples are given to illustrate the theory.

ISSN:0886-9383    

DOI:10.1002/cem.1180050106

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0886-9383    

DOI:10.1002/cem.1180050107

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0886-9383    

DOI:10.1002/cem.1180050108

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0886-9383    

DOI:10.1002/cem.1180050109

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0886-9383    

DOI:10.1002/cem.1180050102

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY