New approach to generalized two-dimensional correlation spectroscopy. II: Eigenvalue manipulation transformation (EMT) for noise suppression.
This paper introduces the concept of eigenvalue manipulating transformation (EMT) of a data matrix for noise suppression in two-dimensional (2D) correlation spectroscopy. The FT-IR spectra of a polystyrene/methyl ethyl ketone/toluene solution mixture during the solvent evaporation process, to which were added a substantial amount of artificial noise, have been analyzed. By uniformly raising the power of a set of eigenvalues, the major eigenvalues become more prominent. As a consequence, minor eigenvectors representing the noise component are no longer strongly represented in the reconstructed data. This EMT operation is similar to the simple truncation of noise-dominated minor factors practiced in standard principal component analysis (PCA), as demonstrated in our preceding paper on PCA-2D correlation spectroscopy. The effect of this new EMT scheme is more gradual, with attractive flexibility to continuously fine-tune the balance between the desired noise reduction effect and the retention of pertinent spectral information.
Jung
Young Mee
YM
Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Pohang 790-784, Korea. ymjung@postech.ac.kr
Kim
Seung Bin
SB
Noda
Isao
I
D000465:Algorithms; D016477:Artifacts; D002074:Butanones / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D025341:Principal Component Analysis; D011786:Quality Control; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013223:Statistics as Topic; D013269:Stochastic Processes; D014050:Toluene / Q000737:chemistry*
D002074:Butanones; D011137:Polystyrenes; D012996:Solutions; D012997:Solvents; D014050:Toluene; C005222:methylethyl ketone