Journal of Chemometrics

Cover image for Journal of Chemometrics

Special Issue: WSC-7: 7th Winter Symposium on Chemometrics

July 2011

Volume 25, Issue 7

Pages 349–399

Issue edited by: Dr. Oxana Ye. Rodionova

  1. Meeting Articles

    1. Top of page
    2. Meeting Articles
    3. Special Issue Articles
  2. Special Issue Articles

    1. Top of page
    2. Meeting Articles
    3. Special Issue Articles
    1. Reconstruction of chromatographic peaks using the exponentially modified Gaussian function (pages 352–356)

      Yuri Kalambet, Yuri Kozmin, Ksenia Mikhailova, Igor Nagaev and Pavel Tikhonov

      Article first published online: 21 FEB 2011 | DOI: 10.1002/cem.1343

      An improved way to calculate the exponentially modified Gaussian (EMG) function is offered. Peak deconvolution routine, based on the EMG peak shape and linear optimization methods, is applied to the reconstruction of out-of-range peaks, the shape of which was distorted by detector overload. The accuracy of peak reconstruction is evaluated.

    2. Monitoring of biogas test plants—a process analytical technology approach (pages 357–365)

      Jens Bo Holm-Nielsen and Kim H. Esbensen

      Article first published online: 29 MAR 2011 | DOI: 10.1002/cem.1344

      By this study it is fully proven that on-line monitoring of volatile fatty acids (VFA) are obtainable during anaerobic digestion processes. The AD process is severely damaged by too high VFA concentration levels. Therefore on-line monitoring programs and tools are highly needed for process analytical technologies in anaerobic digestion and similar biorefinery processes.

    3. Finding relevant clustering directions in high-dimensional data using Particle Swarm Optimization (pages 366–374)

      Federico Marini and Beata Walczak

      Article first published online: 22 OCT 2010 | DOI: 10.1002/cem.1345

      A method based on Particle Swarm Optimization (PSO) is proposed and described for finding subspaces that carry meaningful information about the presence of groups in high-dimensional data sets. The method was successfully used on two simulated data set and on a real matrix coming from the analysis of genomic microarrays.

    4. Preventing over-fitting in PLS calibration models of near-infrared (NIR) spectroscopy data using regression coefficients (pages 375–381)

      A. A. Gowen, G. Downey, C. Esquerre and C. P. O'Donnell

      Article first published online: 22 OCT 2010 | DOI: 10.1002/cem.1349

      A simple method for quantifying the shape and size of a regression coefficient is presented. This measure can be combined with an indicator of model bias (e.g. root mean square error) to aid in estimation of the appropriate number of LVs to include in a PLS model. The performance of the proposed method is evaluated on simulated and real data sets and compared with several existing methods.

    5. Predictive power of LDA to discriminate abnormal wine fermentations (pages 382–388)

      Alejandra Urtubia and Jean-Michel Roger

      Article first published online: 21 FEB 2011 | DOI: 10.1002/cem.1362

      Predictive power of Stepwise Linear Discriminant Analysis (SLDA) was evaluated to discriminate the behavior of wine fermentation. Information of different chemical concentrations from industrial wine fermentations was used. Procedure consisted of non linear curve fitting and SLDA applied to the parameters of the curve. The correlation coefficient of alcoholic degree, initial concentration of glucose, initial density and correlation coefficient of tartaric acid were the variables more discriminant and they indicated some differences between a normal and abnormal fermentation.

    6. In-line monitoring of Saccharomyces cerevisiae fermentation with a fluorescence probe: new approaches to data collection and analysis (pages 389–399)

      Andrey Bogomolov, Thorsten Grasser and Martin Hessling

      Article first published online: 1 FEB 2011 | DOI: 10.1002/cem.1365

      A new fluorescence Lighthouse™ Probe (LHP) has been applied in-line to monitor Saccharomyces cerevisiae fermentation in a lab reactor. Exploratory data analysis of two fed-batch cultivations has been performed using Partial Least Squares regression and Multivariate Curve Resolution. A simple algorithm for the resolution of process profiles and two-dimensional spectra of individual fluorophores from three-way fluorescence data in the presence of intensive scatter has been suggested and applied to the process diagnostics.