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Related papers: Toward Long-Tailed Online Anomaly Detection throug…

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Long-tailed data is a special type of multi-class imbalanced data with a very large amount of minority/tail classes that have a very significant combined influence. Long-tailed learning aims to build high-performance models on datasets with…

Machine Learning · Computer Science 2024-08-02 Chongsheng Zhang , George Almpanidis , Gaojuan Fan , Binquan Deng , Yanbo Zhang , Ji Liu , Aouaidjia Kamel , Paolo Soda , João Gama

Existing approaches towards anomaly detection~(AD) often rely on a substantial amount of anomaly-free data to train representation and density models. However, large anomaly-free datasets may not always be available before the inference…

Computer Vision and Pattern Recognition · Computer Science 2024-03-01 Jingyi Liao , Xun Xu , Manh Cuong Nguyen , Adam Goodge , Chuan Sheng Foo

Image anomaly detection and localization perform not only image-level anomaly classification but also locate pixel-level anomaly regions. Recently, it has received much research attention due to its wide application in various fields. This…

Computer Vision and Pattern Recognition · Computer Science 2024-05-28 Chao Huang , Zhao Kang , Hong Wu

Time series anomaly detection (TSAD) plays a crucial role in various industries by identifying atypical patterns that deviate from standard trends, thereby maintaining system integrity and enabling prompt response measures. Traditional TSAD…

Computation and Language · Computer Science 2024-05-27 Jun Liu , Chaoyun Zhang , Jiaxu Qian , Minghua Ma , Si Qin , Chetan Bansal , Qingwei Lin , Saravan Rajmohan , Dongmei Zhang

Anomaly detection (AD) is the identification of data samples that do not fit a learned data distribution. As such, AD systems can help physicians to determine the presence, severity, and extension of a pathology. Deep generative models,…

Image and Video Processing · Electrical Eng. & Systems 2021-04-12 Jaime Simarro , Ezequiel de la Rosa , Thijs Vande Vyvere , David Robben , Diana M. Sima

Video anomaly detection (VAD) aims to detect anomalies that deviate from what is expected. In open-world scenarios, the expected events may change as requirements change. For example, not wearing a mask may be considered abnormal during a…

Computer Vision and Pattern Recognition · Computer Science 2026-03-04 Zihao Liu , Xiaoyu Wu , Jianqin Wu , Xuxu Wang , Linlin Yang

The introduction of negative labels (NLs) has proven effective in enhancing Out-of-Distribution (OOD) detection. However, existing methods often lack an understanding of OOD images, making it difficult to construct an accurate negative…

Computer Vision and Pattern Recognition · Computer Science 2026-03-18 Wenjie Zhu , Yabin Zhang , Xin Jin , Wenjun Zeng , Lei Zhang

The ongoing challenges in time series anomaly detection (TSAD), notably the scarcity of anomaly labels and the variability in anomaly lengths and shapes, have led to the need for a more efficient solution. As limited anomaly labels hinder…

Machine Learning · Computer Science 2023-11-28 Yuting Sun , Guansong Pang , Guanhua Ye , Tong Chen , Xia Hu , Hongzhi Yin

Previous OOD detection systems only focus on the semantic gap between ID and OOD samples. Besides the semantic gap, we are faced with two additional gaps: the domain gap between source and target domains, and the class-imbalance gap between…

Computer Vision and Pattern Recognition · Computer Science 2026-05-26 Xiang Fang , Arvind Easwaran , Blaise Genest , Ponnuthurai Nagaratnam Suganthan

Graph anomaly detection is crucial for identifying nodes that deviate from regular behavior within graphs, benefiting various domains such as fraud detection and social network. Although existing reconstruction-based methods have achieved…

Machine Learning · Computer Science 2023-12-25 Junwei He , Qianqian Xu , Yangbangyan Jiang , Zitai Wang , Qingming Huang

Graph anomaly detection (GAD), which aims to identify abnormal nodes that differ from the majority within a graph, has garnered significant attention. However, current GAD methods necessitate training specific to each dataset, resulting in…

Machine Learning · Computer Science 2024-12-25 Yixin Liu , Shiyuan Li , Yu Zheng , Qingfeng Chen , Chengqi Zhang , Shirui Pan

Log anomaly detection is essential for system reliability, but it is extremely challenging to do considering it involves class imbalance. Additionally, the models trained in one domain are not applicable to other domains, necessitating the…

Machine Learning · Computer Science 2026-01-22 Krishna Sharma , Vivek Yelleti

Anomaly detection, finding patterns that substantially deviate from those seen previously, is one of the fundamental problems of artificial intelligence. Recently, classification-based methods were shown to achieve superior results on this…

Machine Learning · Computer Science 2020-05-06 Liron Bergman , Yedid Hoshen

Current state-of-the-art multi-class unsupervised anomaly detection (MUAD) methods rely on training encoder-decoder models to reconstruct anomaly-free features. We first show these approaches have an inherent fidelity-stability dilemma in…

Computer Vision and Pattern Recognition · Computer Science 2026-02-03 Xingwu Zhang , Guanxuan Li , Paul Henderson , Gerardo Aragon-Camarasa , Zijun Long

Object detection is a pivotal task in computer vision that has received significant attention in previous years. Nonetheless, the capability of a detector to localise objects out of the training distribution remains unexplored. Whilst…

Computer Vision and Pattern Recognition · Computer Science 2024-07-23 Brian K. S. Isaac-Medina , Yona Falinie A. Gaus , Neelanjan Bhowmik , Toby P. Breckon

Time series are ubiquitous and occur naturally in a variety of applications -- from data recorded by sensors in manufacturing processes, over financial data streams to climate data. Different tasks arise, such as regression, classification…

Machine Learning · Computer Science 2024-09-17 Sebastian Wette , Florian Heinrichs

Graph anomaly detection (GAD) is a vital task in graph-based machine learning and has been widely applied in many real-world applications. The primary goal of GAD is to capture anomalous nodes from graph datasets, which evidently deviate…

Machine Learning · Computer Science 2022-12-05 Jingcan Duan , Siwei Wang , Pei Zhang , En Zhu , Jingtao Hu , Hu Jin , Yue Liu , Zhibin Dong

Despite the rapid advance of unsupervised anomaly detection, existing methods require to train separate models for different objects. In this work, we present UniAD that accomplishes anomaly detection for multiple classes with a unified…

Computer Vision and Pattern Recognition · Computer Science 2022-10-26 Zhiyuan You , Lei Cui , Yujun Shen , Kai Yang , Xin Lu , Yu Zheng , Xinyi Le

Fully Unsupervised Anomaly Detection (FUAD) is a practical extension of Unsupervised Anomaly Detection (UAD), aiming to detect anomalies without any labels even when the training set may contain anomalous samples. To achieve FUAD, we…

Computer Vision and Pattern Recognition · Computer Science 2025-08-26 Xinyue Liu , Jianyuan Wang , Biao Leng , Shuo Zhang

Semi-supervised Anomaly Detection (AD) is a kind of data mining task which aims at learning features from partially-labeled datasets to help detect outliers. In this paper, we classify existing semi-supervised AD methods into two…

Machine Learning · Computer Science 2022-10-27 Chao Chen , Dawei Wang , Feng Mao , Zongzhang Zhang , Yang Yu