title: [Study of selecting characteristic wavelengths in qualitative analysis of near infrared spectroscopy].
abstract: The present article proposed a method of stepwise selecting characteristic wavelengths based on minimum sum of correlation coefficients (SMCC). The maximization of the ratio of inter-class Euclidean distance to the sum of inner-class Euclidean distances was used as evaluation basis in qualitative analysis of near infrared spectroscopy. Seventeen kinds of grading tobacco leaf in 2012, provided by Hongta Group, were used as experimental samples to verify the effectiveness of this new method. CO1 was selected as the reference category and ten points were selected as characteristic wavelengths. The results indicated that the average value of inner-class Euclidean distance, calculated by characteristic wavelengths, was 1.69 times as large as that calculated by all wavelengths. The average value of inter-class Euclidean distance, calculated by characteristic wavelengths, was 3.70 times as large as that calculated by all wavelengths. The average value of the ratio of inter-class Euclidean distance to the sum of inner-class Euclidean distances, calculated by characteristic wavelength, was 2.21 times as large as that calculated by all wavelengths. The ratio of characteristic wavelengths was increased. The characteristic wavelengths can express the classical differences. It was showed that SMCC was an effective way to select characteristic wavelengths in qualitative analyses of near infrared spectroscopy.
authors.affiliation: College of Information and Electrical Engineering, China Agricultural University, Beijing 100083, China. endlessyujing@sina.com
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.affiliation: Hongta Tobacco (Group) Co., Ltd., Yuxi 653100, China.
authors.forename: Ya-Dong
authors.initials: YD
authors.lastname: Wen
authors.affiliation: Hongta Tobacco (Group) Co., Ltd., Yuxi 653100, China.
authors.forename: Luo-Ping
authors.initials: LP
authors.lastname: Wang
authors.affiliation: Hongta Tobacco (Group) Co., Ltd., Yuxi 653100, China.
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Qian
authors.affiliation: Hongta Tobacco (Group) Co., Ltd., Yuxi 653100, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Ma
authors.affiliation: Hongta Tobacco (Group) Co., Ltd., Yuxi 653100, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Information and Electrical Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Long-Lian
authors.initials: LL
authors.lastname: Zhao
authors.affiliation: College of Information and Electrical Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Jun-Hui
authors.initials: JH
authors.lastname: Li