Tomas Öberg

Hem : Kompetens : Presentationer : Linear free energy relationships and latent variable methods - Similarity in modelling environmentally relevant properties

Öberg, T., Liu, T.
Posterpresentation vid SETAC Europe 19th Annual Meeting i Göteborg, 31 maj-4 juni, 2009

Abstract
Estimation methods for partition constants are needed in many fields of engineering and science. The partitioning between phases is determined by the free energy of transfer and all estimation methods must therefore describe the same entity. Linear solvation energy relationships (LSER) try to split the contributions to van der Waals and polar interactions into directly interpretable solute descriptors; while projection based regression methods can accomplish a similar dimensionality reduction from a set of theoretical descriptors. Here we use the partitioning between octanol and water (Kow) and water solubility (Sw) to investigate similarities and differences between LSER and latent variable models based on partial least squares regression (PLSR). The similarity in model structure is described, and shown to transform into a comparable prediction performance. We also demonstrate the opportunity to accomplish an analogous chemical interpretation of the latent variable model - either directly or through a linear transformation of the PLS factors - as with a LSER model. Much of the alleged difference between the mechanistic or semi-empirical LSER and the statistical PLSR models will then disappear. The choice of a modelling approach should therefore primarily be driven by the availability of data and predictive performance.

Poster som en PDF-fil, 82 kbPDF

Se även tidskriftsartikeln: Modelling of partition constants: Linear solvation energy relationships or PLS regression?


In EnglishEnglish homepage

© Tomas Öberg  Översikt
Kontakt