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Related papers: COPOD: Copula-Based Outlier Detection

200 papers

Normalizing flows are prominent deep generative models that provide tractable probability distributions and efficient density estimation. However, they are well known to fail while detecting Out-of-Distribution (OOD) inputs as they directly…

Machine Learning · Computer Science 2021-11-17 Nishant Kumar , Pia Hanfeld , Michael Hecht , Michael Bussmann , Stefan Gumhold , Nico Hoffmann

There exist multiple methods to detect outliers in multivariate data in the literature, but most of them require to estimate the covariance matrix. The higher the dimension, the more complex the estimation of the matrix becoming impossible…

Methodology · Statistics 2020-12-01 P. Navarro-Esteban , J. A. Cuesta-Albertos

Change point detection (CPD) and anomaly detection (AD) are essential techniques in various fields to identify abrupt changes or abnormal data instances. However, existing methods are often constrained to univariate data, face scalability…

Outlier detection and cleaning are essential steps in data preprocessing to ensure the integrity and validity of data analyses. This paper focuses on outlier points within individual trajectories, i.e., points that deviate significantly…

Databases · Computer Science 2025-11-26 Mariana M Garcez Duarte , Mahmoud Sakr

Transformers excel in natural language processing and computer vision tasks. However, they still face challenges in generalizing to Out-of-Distribution (OOD) datasets, i.e. data whose distribution differs from that seen during training. OOD…

Machine Learning · Computer Science 2026-01-30 Yijin Zhou , Yutang Ge , Wenyuan Xie , Linqian Zeng , Xiaowen Dong , Yuguang Wang

Research on Out-Of-Distribution (OOD) detection focuses mainly on building scores that efficiently distinguish OOD data from In Distribution (ID) data. On the other hand, Conformal Prediction (CP) uses non-conformity scores to construct…

Machine Learning · Statistics 2024-03-19 Paul Novello , Joseba Dalmau , Léo Andeol

In order to allow machine learning algorithms to extract knowledge from raw data, these data must first be cleaned, transformed, and put into machine-appropriate form. These often very time-consuming phase is referred to as preprocessing.…

Machine Learning · Computer Science 2021-11-19 David Cemernek

Anomaly detection in real-world scenarios poses challenges due to dynamic and often unknown anomaly distributions, requiring robust methods that operate under an open-world assumption. This challenge is exacerbated in practical settings,…

Machine Learning · Computer Science 2024-04-24 Dayananda Herurkar , Sebastian Palacio , Ahmed Anwar , Joern Hees , Andreas Dengel

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

This paper develops a flexible distribution-free method for collective outlier detection and enumeration, designed for situations in which the presence of outliers can be detected powerfully even though their precise identification may be…

Methodology · Statistics 2026-05-19 Chiara G. Magnani , Matteo Sesia , Aldo Solari

Outlier detection has received special attention in various fields, mainly for those dealing with machine learning and artificial intelligence. As strong outliers, anomalies are divided into the point, contextual and collective outliers.…

Machine Learning · Computer Science 2020-01-29 Rasoul Kiani , Amin Keshavarzi , Mahdi Bohlouli

We study a novel outlier detection problem that aims to identify abnormal input-output associations in data, whose instances consist of multi-dimensional input (context) and output (responses) pairs. We present our approach that works by…

Artificial Intelligence · Computer Science 2017-08-04 Charmgil Hong , Siqi Liu , Milos Hauskrecht

Outlier detection refers to the identification of anomalous samples that deviate significantly from the distribution of normal data and has been extensively studied and used in a variety of practical tasks. However, most unsupervised…

Machine Learning · Computer Science 2025-01-07 Can Gao , Xiaofeng Tan , Jie Zhou , Weiping Ding , Witold Pedrycz

Due to the intractability of characterizing everything that looks unlike the normal data, anomaly detection (AD) is traditionally treated as an unsupervised problem utilizing only normal samples. However, it has recently been found that…

Computer Vision and Pattern Recognition · Computer Science 2023-01-29 Philipp Liznerski , Lukas Ruff , Robert A. Vandermeulen , Billy Joe Franks , Klaus-Robert Müller , Marius Kloft

Outlier detection is a technique in data mining that aims to detect unusual or unexpected records in the dataset. Existing outlier detection algorithms have different pros and cons and exhibit different sensitivity to noisy data such as…

Machine Learning · Computer Science 2023-12-22 Yuanyuan Wei , Julian Jang-Jaccard , Fariza Sabrina , Timothy McIntosh

Anomaly detection aims to detect data that do not conform to regular patterns, and such data is also called outliers. The anomalies to be detected are often tiny in proportion, containing crucial information, and are suitable for…

Machine Learning · Computer Science 2023-06-06 Fan Xu , Nan Wang , Xibin Zhao

The HDoutliers algorithm is a powerful unsupervised algorithm for detecting anomalies in high-dimensional data, with a strong theoretical foundation. However, it suffers from some limitations that significantly hinder its performance level,…

Machine Learning · Statistics 2019-08-13 Priyanga Dilini Talagala , Rob J. Hyndman , Kate Smith-Miles

This paper introduces a novel family of outlier detection algorithms based on Cluster Catch Digraphs (CCDs), specifically tailored to address the challenges of high dimensionality and varying cluster shapes, which deteriorate the…

Machine Learning · Statistics 2024-10-10 Rui Shi , Nedret Billor , Elvan Ceyhan

Event sequence data record the occurrences of events in continuous time. Event sequence forecasting based on temporal point processes (TPPs) has been extensively studied, but outlier or anomaly detection, especially without any supervision…

Machine Learning · Computer Science 2024-11-26 Somjit Nath , Yik Chau Lui , Siqi Liu

This paper presents a fast methodology, called ROBOUT, to identify outliers in a response variable conditional on a set of linearly related predictors, retrieved from a large granular dataset. ROBOUT is shown to be effective and…

Methodology · Statistics 2021-04-27 Matteo Farnè , Angelos Vouldis