title: New approach to generalized two-dimensional correlation spectroscopy. II: Eigenvalue manipulation transformation (EMT) for noise suppression.
abstract: 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.
authors.affiliation: Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Pohang 790-784, Korea. ymjung@postech.ac.kr
authors.forename: Young Mee
authors.initials: YM
authors.lastname: Jung
authors.forename: Seung Bin
authors.initials: SB
authors.lastname: Kim
authors.forename: Isao
authors.initials: I
authors.lastname: Noda
mesh_terms: 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*
chemical_list: D002074:Butanones; D011137:Polystyrenes; D012996:Solutions; D012997:Solvents; D014050:Toluene; C005222:methylethyl ketone