See also the following links:

▎ENGLISH

kNN for Anomaly Detection
▸ https://nandhini-aitec.medium.com/day-29-knn-avgknn-medknn-for-identifying-outliers-1e3881227669

Local Outlier Factor - Wikipedia
▸ https://en.wikipedia.org/wiki/Local_outlier_factor

▎日 本 語

k近傍法による異常検知
▸ https://qiita.com/ngayope330/items/fc941b8d49b90319748e

LOFによるデータ密度の推定・外れサンプル(外れ値)の検出・異常検出
▸ https://datachemeng.com/local_outlier_factor/