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Outlier detection and concept drift detection represent two challenges in data analysis. Most studies address these issues separately. However, joint detection mechanisms in regression remain underexplored, where the continuous nature of…

Methodology · Statistics 2025-12-16 Bingbing Wang , Shengyan Sun , Jiaqi Wang , Yu Tang

Out-of-distribution (OOD) detection is essential for deploying machine learning models in open-world and safety-critical scenarios, where test inputs may deviate from the training distribution and overconfident predictions on unknown…

Machine Learning · Computer Science 2026-05-28 Fengqiang Wan , Qing-Yuan Jiang , Yang Yang

An outlier is an event or observation that is defined as an unusual activity, intrusion, or a suspicious data point that lies at an irregular distance from a population. The definition of an outlier event, however, is subjective and depends…

Machine Learning · Computer Science 2021-12-02 Md Nazmul Kabir Sikder , Feras A. Batarseh

Outlier or anomaly detection is an important task in data analysis. We discuss the problem from a geometrical perspective and provide a framework that exploits the metric structure of a data set. Our approach rests on the manifold…

Machine Learning · Statistics 2022-08-01 Moritz Herrmann , Florian Pfisterer , Fabian Scheipl

Support Vector Machines have been successfully used for one-class classification (OCSVM, SVDD) when trained on clean data, but they work much worse on dirty data: outliers present in the training data tend to become support vectors, and are…

Machine Learning · Computer Science 2022-12-29 Daniel Boiar , Thomas Liebig , Erich Schubert

Learning expressive low-dimensional representations of ultrahigh-dimensional data, e.g., data with thousands/millions of features, has been a major way to enable learning methods to address the curse of dimensionality. However, existing…

Machine Learning · Computer Science 2018-06-14 Guansong Pang , Longbing Cao , Ling Chen , Huan Liu

AutoEncoders (AEs) are commonly used for machine learning tasks due to their intrinsic learning ability. This unique characteristic can be capitalized for Outlier Detection (OD). However conventional AE-based methods face the issue of…

Machine Learning · Computer Science 2024-07-10 Xu Tan , Jiawei Yang , Junqi Chen , Sylwan Rahardja , Susanto Rahardja

Despite tremendous progress in outlier detection research in recent years, the majority of existing methods are designed only to detect unconditional outliers that correspond to unusual data patterns expressed in the joint space of all data…

Machine Learning · Computer Science 2016-12-23 Charmgil Hong , Milos Hauskrecht

The outlier exposure method is an effective approach to address the unsupervised anomaly sound detection problem. The key focus of this method is how to make the model learn the distribution space of normal data. Based on biological…

Sound · Computer Science 2025-09-22 Xinxin Meng , Jiangtao Guo , Yunxiang Zhang , Shun Huang

In this work, we revisit outlier hypothesis testing and propose exponentially consistent, low-complexity fixed-length tests that achieve a better tradeoff between detection performance and computational complexity than existing…

Signal Processing · Electrical Eng. & Systems 2026-01-28 Lina Zhu , Lin Zhou

In a corpus of data, outliers are either errors: mistakes in the data that are counterproductive, or are unique: informative samples that improve model robustness. Identifying outliers can lead to better datasets by (1) removing noise in…

The memory dictionary-based contrastive learning method has achieved remarkable results in the field of unsupervised person Re-ID. However, The method of updating memory based on all samples does not fully utilize the hardest sample to…

Computer Vision and Pattern Recognition · Computer Science 2024-04-09 Lingzhi Liu , Haiyang Zhang , Chengwei Tang , Tiantian Zhang

The problem of outlier detection is extremely challenging in many domains such as text, in which the attribute values are typically non-negative, and most values are zero. In such cases, it often becomes difficult to separate the outliers…

Information Retrieval · Computer Science 2017-01-06 Ramakrishnan Kannan , Hyenkyun Woo , Charu C. Aggarwal , Haesun Park

Time series data occurs widely, and outlier detection is a fundamental problem in data mining, which has numerous applications. Existing autoencoder-based approaches deliver state-of-the-art performance on challenging real-world data but…

Machine Learning · Computer Science 2022-04-08 Tung Kieu , Bin Yang , Chenjuan Guo , Christian S. Jensen , Yan Zhao , Feiteng Huang , Kai Zheng

Unsupervised Anomaly Detection (UAD) with incremental training is crucial in industrial manufacturing, as unpredictable defects make obtaining sufficient labeled data infeasible. However, continual learning methods primarily rely on…

Computer Vision and Pattern Recognition · Computer Science 2024-01-03 Jiaqi Liu , Kai Wu , Qiang Nie , Ying Chen , Bin-Bin Gao , Yong Liu , Jinbao Wang , Chengjie Wang , Feng Zheng

The quantification of uncertainty is important for the adoption of machine learning, especially to reject out-of-distribution (OOD) data back to human experts for review. Yet progress has been slow, as a balance must be struck between…

Machine Learning · Computer Science 2022-09-12 Derek Everett , Andre T. Nguyen , Luke E. Richards , Edward Raff

Outlier detection is a critical task in data mining, aimed at identifying objects that significantly deviate from the norm. Semi-supervised methods improve detection performance by leveraging partially labeled data but typically overlook…

Machine Learning · Computer Science 2025-12-23 Baiyang Chen , Zhong Yuan , Zheng Liu , Dezhong Peng , Yongxiang Li , Chang Liu , Guiduo Duan

The outlier detection problem in some cases is similar to the classification problem. For example, the main concern of clustering-based outlier detection algorithms is to find clusters and outliers, which are often regarded as noise that…

Machine Learning · Computer Science 2014-05-25 M. H. Marghny , Ahmed I. Taloba

Outlier detection (OD) is a key learning task for finding rare and deviant data samples, with many time-critical applications such as fraud detection and intrusion detection. In this work, we propose TOD, the first tensor-based system for…

Machine Learning · Computer Science 2022-09-20 Yue Zhao , George H. Chen , Zhihao Jia

Anomaly detection aims at identifying data points that show systematic deviations from the majority of data in an unlabeled dataset. A common assumption is that clean training data (free of anomalies) is available, which is often violated…

Machine Learning · Computer Science 2022-07-20 Chen Qiu , Aodong Li , Marius Kloft , Maja Rudolph , Stephan Mandt