Scent Classification by K Nearest Neighbors using Ion-Mobility Spectrometry Measurements

Philipp Müller, Katri Salminen, Ville Nieminen, Anton Kontunen, Markus Karjalainen, Poika Isokoski, Jussi Rantala, Mariaana Savia, Jari Väliaho, Pasi Kallio, Jukka Lekkala, Veikko Surakka

    Research output: Contribution to journalArticleScientificpeer-review

    12 Citations (Scopus)
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    Various classifiers for scent classification based on measurements using an electronic nose (eNose) have been studied recently. In general, classifiers rely on a static database containing reference eNose measurements for known scents. However, most of these approaches require retraining of the classifier every time a new scent needs to be added to the training database. In this paper, the potential of a K nearest neighbors (KNN) classifier is investigated to avoid the time-consuming retraining when updating the database. To speed up classification, a k-dimensional tree search in the KNN classifier and principal component analysis (PCA) are studied. The tests with scents presented to an eNose based on ion-mobility spectrometry (IMS) show that the KNN method classifies scents with high accuracy. Using a k-dimensional tree search instead of an exhaustive search has no significant influence on the misclassification rate but reduces the classification time considerably. The use of PCA-transformed data results in a higher misclassification rate than the use of IMS data when only the first principal components explaining 95% of the total variance are used but in a similar misclassification rate when the first principal components explaining 99% of the total variance are used. In conclusion, the proposed method can be recommended for classifying scents measured with IMS-based eNoses.
    Original languageEnglish
    Pages (from-to)593-606
    JournalExpert Systems with Applications
    Publication statusPublished - 2019
    Publication typeA1 Journal article-refereed

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