ISSN:0886-9383    

DOI:10.1002/cem.1180030103

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe details of a general multiblock partial least squares (PLS) algorithm based on one originally presented by Woldet al.have been developed and are completely presented. The algorithm can handle most types of relationships between the blocks and constitutes a significant advancement in the modeling of complex chemical systems. The algorithm has been programmed in FORTRAN and has been tested on two simulated multiblock problems, a three‐block and a five‐block problem. The algorithm combines the score vectors for all blocks predicting a particular block into a new block. This new block is used to predict the predicted block in a manner analogous to the two‐block PLS. In a similar manner if one block predicts more than one other block, the score vectors of all predicted blocks are combined to form a new block, which is then predicted by the predictor block as in the two‐block PLS. Blocks that both predict and are predicted are treated in such a way that both of these roles can be taken into account when calculating interblock relationships. The results of numerical simulations indicate that the computer program is operating properly and that the multiblock PLS produces meaningful and consistent

ISSN:0886-9383    

DOI:10.1002/cem.1180030104

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe effect of peak shifts on the performance of a Kalman filter multicomponent analysis algorithm has been investigated. A series of Gaussian test systems were employed to characterize the concentration estimation errors and the morphology of the on‐line residuals (the innovations sequence). Both forward and reverse filters were used in the generation of the innovations sequences. It was found that the difference between the forward and reverse innovations sequences gave an accurate indication of the direction and magnitude of the peak shift. A series of overlapped two‐component systems were also investigated. Again, a correlation between the difference innovations and the degree of the response shift was observed. The behavior of the Kalman filter in fitting the shifted fluorescence emission spectrum of benzo[a]pyrene was also examined. The response for benzo[a]pyrene in cyclohexane solution was compared to that obtained on the surface surface of a reversed phase thin layer chromatography plate. A red shift of 4 nm was detected for the surface spectrum by observing the difference innovations sequence. This approach holds promise for correction of response shifts in multicomponent syst

ISSN:0886-9383    

DOI:10.1002/cem.1180030105

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractA scaffold for detailed understanding of the concept ‘dimensionality’ in data analysis is furnished by a systematic classification of higher‐order data array configurations. Three major types of problem formulation in multivariate data analysis can be characterized for relevantdata classes:1data description(intra‐class data structure modelling of inter‐object and inter‐variable relationships)2classification(inter‐class discrimination)3correlation,regression(inter‐variable relationships).The relationship between these three categories of data analytical problem formulation and the fundamental data array classification is exposed. These relations are augmented to include the general case of data arrays of orderR, andR‐way data analysis with the use of bilinear projections is presented. Based upon this, some possible directions for the future development of data analysi

ISSN:0886-9383    

DOI:10.1002/cem.1180030106

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractFisher variance ratio tests are developed for determining (1) the number of statistically significant abstract factors responsible for a data matrix and (2) the significance of target vectors projected into the abstract factor space.F‐tests, developed from the viewpoint of vector distributions, are applied to various data sets taken from the chemical literatur

ISSN:0886-9383    

DOI:10.1002/cem.1180030107

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractValues of the peak potential, the peak current function and the peak potential difference are extracted from simulated cyclic voltammograms of a quasi‐reversible electron transfer reaction. Variations of the feature values are described by empirical functions of the model parameters α (transfer coefficient) and ψ′ (dimensionless form of the heterogeneous electron transfer rate constantks) using multiple linear regression. These functions are used to determine the system parameters α andksfrom test data sets of feature values. The predictive power of the features is discussed. It is shown that several features can be used simultaneously in the analysis. Also, α,ks, the formal potentialE0and the diffusion coefficientDcan be estimated simultaneously. Experimental data from the metal‐centered one‐electron reduction of cerium (IV) bis(octaethylporphyrinate), Ce(OEP)2, are analyzed using the technique, and values of the system parameters for this electrochemical reaction are

ISSN:0886-9383    

DOI:10.1002/cem.1180030108

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractA computer program (FEA) is presented for processing historical laboratory data. It performs on a list of sample entries stored in a laboratory information management system. Using an algorithm which is based on fuzzy set theory, FEA classifies the entries into a limited number of clusters called sample types. The classification is fully user‐defined. The program transforms the historical data into a representation which is more suitable for studying the performance of the laboratory or which can be used as preparation for a simulation projec

ISSN:0886-9383    

DOI:10.1002/cem.1180030109

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

ISSN:0886-9383    

DOI:10.1002/cem.1180030110

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

ISSN:0886-9383    

DOI:10.1002/cem.1180030111

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

ISSN:0886-9383    

DOI:10.1002/cem.1180030112

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY