Text Anomaly Detection with Simplified Isolation Kernel

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Cao, Yang, Yang, Sikun, Yang, Yujiu, Qi, Lianyong, Liu, Ming
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866909983015174144
author Cao, Yang
Yang, Sikun
Yang, Yujiu
Qi, Lianyong
Liu, Ming
author_facet Cao, Yang
Yang, Sikun
Yang, Yujiu
Qi, Lianyong
Liu, Ming
contents Two-step approaches combining pre-trained large language model embeddings and anomaly detectors demonstrate strong performance in text anomaly detection by leveraging rich semantic representations. However, high-dimensional dense embeddings extracted by large language models pose challenges due to substantial memory requirements and high computation time. To address this challenge, we introduce the Simplified Isolation Kernel (SIK), which maps high-dimensional dense embeddings to lower-dimensional sparse representations while preserving crucial anomaly characteristics. SIK has linear time complexity and significantly reduces space complexity through its innovative boundary-focused feature mapping. Experiments across 7 datasets demonstrate that SIK achieves better detection performance than 11 state-of-the-art (SOTA) anomaly detection algorithms while maintaining computational efficiency and low memory cost. All code and demonstrations are available at https://github.com/charles-cao/SIK.
format Preprint
id arxiv_https___arxiv_org_abs_2510_13197
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Text Anomaly Detection with Simplified Isolation Kernel
Cao, Yang
Yang, Sikun
Yang, Yujiu
Qi, Lianyong
Liu, Ming
Computation and Language
Two-step approaches combining pre-trained large language model embeddings and anomaly detectors demonstrate strong performance in text anomaly detection by leveraging rich semantic representations. However, high-dimensional dense embeddings extracted by large language models pose challenges due to substantial memory requirements and high computation time. To address this challenge, we introduce the Simplified Isolation Kernel (SIK), which maps high-dimensional dense embeddings to lower-dimensional sparse representations while preserving crucial anomaly characteristics. SIK has linear time complexity and significantly reduces space complexity through its innovative boundary-focused feature mapping. Experiments across 7 datasets demonstrate that SIK achieves better detection performance than 11 state-of-the-art (SOTA) anomaly detection algorithms while maintaining computational efficiency and low memory cost. All code and demonstrations are available at https://github.com/charles-cao/SIK.
title Text Anomaly Detection with Simplified Isolation Kernel
topic Computation and Language
url https://arxiv.org/abs/2510.13197