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Standard approaches for variable selection in linear models are not tailored to deal properly with high-dimensional and incomplete data. Currently, methods dedicated to high-dimensional data handle missing values by ad-hoc strategies, like…

Methodology · Statistics 2021-06-09 Avner Bar-Hen , Vincent Audigier

Nonnegative Matrix Factorization (NMF) is a widely-used data analysis technique, and has yielded impressive results in many real-world tasks. Generally, existing NMF methods represent each sample with several centroids, and find the optimal…

Image and Video Processing · Electrical Eng. & Systems 2021-03-26 Mulin Chen , Xuelong Li

In anomaly detection, a prominent task is to induce a model to identify anomalies learned solely based on normal data. Generally, one is interested in finding an anomaly detector that correctly identifies anomalies, i.e., data points that…

Machine Learning · Computer Science 2022-11-28 David Schubert , Pritha Gupta , Marcel Wever

Conventional defect detection systems in Automated Fibre Placement (AFP) typically rely on end-to-end supervised learning, necessitating a substantial number of labelled defective samples for effective training. However, the scarcity of…

Computer Vision and Pattern Recognition · Computer Science 2024-03-07 Assef Ghamisi , Todd Charter , Li Ji , Maxime Rivard , Gil Lund , Homayoun Najjaran

Traditional anomaly detection methods aim to identify objects that deviate from most other objects by treating all features equally. In contrast, contextual anomaly detection methods aim to detect objects that deviate from other objects…

Machine Learning · Computer Science 2023-08-07 Zhong Li , Matthijs van Leeuwen

Unsupervised anomaly detection stands as an important problem in machine learning, with applications in financial fraud prevention, network security and medical diagnostics. Existing unsupervised anomaly detection algorithms rarely perform…

Machine Learning · Computer Science 2026-02-04 Pritam Kar , Rahul Bordoloi , Olaf Wolkenhauer , Saptarshi Bej

Anomaly detection (AD) plays an important role in numerous applications. We focus on two understudied aspects of AD that are critical for integration into real-world applications. First, most AD methods cannot incorporate labeled data that…

Machine Learning · Computer Science 2023-06-06 Chun-Hao Chang , Jinsung Yoon , Sercan Arik , Madeleine Udell , Tomas Pfister

Large language models (LLMs) have shown their potential in long-context understanding and mathematical reasoning. In this paper, we study the problem of using LLMs to detect tabular anomalies and show that pre-trained LLMs are zero-shot…

Machine Learning · Computer Science 2024-06-25 Aodong Li , Yunhan Zhao , Chen Qiu , Marius Kloft , Padhraic Smyth , Maja Rudolph , Stephan Mandt

Deep generative networks trained via maximum likelihood on a natural image dataset like CIFAR10 often assign high likelihoods to images from datasets with different objects (e.g., SVHN). We refine previous investigations of this failure at…

Machine Learning · Computer Science 2020-11-03 Robin Tibor Schirrmeister , Yuxuan Zhou , Tonio Ball , Dan Zhang

Anomaly detection attempts at finding examples that deviate from the expected behaviour. Usually, anomaly detection is tackled from an unsupervised perspective because anomalous labels are rare and difficult to acquire. However, the lack of…

Machine Learning · Computer Science 2023-01-10 Lorenzo Perini , Daniele Giannuzzi , Jesse Davis

Practical problems with missing data are common, and statistical methods have been developed concerning the validity and/or efficiency of statistical procedures. On a central focus, there have been longstanding interests on the mechanism…

Methodology · Statistics 2020-03-26 Rui Duan , C. Jason Liang , Pamela Shaw , Cheng Yong Tang , Yong Chen

Anomaly detection methods can be very useful in identifying unusual or interesting patterns in data. A recently proposed conditional anomaly detection framework extends anomaly detection to the problem of identifying anomalous patterns on a…

Machine Learning · Computer Science 2026-05-04 Michal Valko , Milos Hauskrecht

The detection and localization of anomalies is one important medical image analysis task. Most commonly, Computer Vision anomaly detection approaches rely on manual annotations that are both time consuming and expensive to obtain.…

Computer Vision and Pattern Recognition · Computer Science 2023-11-14 Sergio Naval Marimont , Giacomo Tarroni

For the purpose of monitoring the behavior of complex infrastructures (e.g. aircrafts, transport or energy networks), high-rate sensors are deployed to capture multivariate data, generally unlabeled, in quasi continuous-time to detect…

Machine Learning · Statistics 2019-10-10 Guillaume Staerman , Pavlo Mozharovskyi , Stephan Clémençon , Florence d'Alché-Buc

This study introduces SECODA, a novel general-purpose unsupervised non-parametric anomaly detection algorithm for datasets containing continuous and categorical attributes. The method is guaranteed to identify cases with unique or sparse…

Databases · Computer Science 2020-08-18 Ralph Foorthuis

Anomaly detection on attributed networks aims to find the nodes whose behaviors are significantly different from other majority nodes. Generally, network data contains information about relationships between entities, and the anomaly is…

Social and Information Networks · Computer Science 2024-01-09 Enbo He , Yitong Hao , Yue Zhang , Guisheng Yin , Lina Yao

We propose a modified density estimation problem that is highly effective for detecting anomalies in tabular data. Our approach assumes that the density function is relatively stable (with lower variance) around normal samples. We have…

Machine Learning · Computer Science 2024-05-09 Amit Rozner , Barak Battash , Henry Li , Lior Wolf , Ofir Lindenbaum

1. Species distribution models (SDM) are tools used to determine environmental features that influence the geographic distribution of species' abundance and have been used to analyze presence-only records. Analysis of presence-only records…

Populations and Evolution · Quantitative Biology 2013-12-05 Trevor Hefley , Andrew Tyre , David Baasch , Erin Blankenship

We make two contributions to the Isolation Forest method for anomaly and outlier detection. The first contribution is an information-theoretically motivated generalisation of the score function that is used to aggregate the scores across…

Machine Learning · Statistics 2023-09-21 Hichem Dhouib , Alissa Wilms , Paul Boes

Visual defect assessment is a form of anomaly detection. This is very relevant in finding faults such as cracks and markings in various surface inspection tasks like pavement and automotive parts. The task involves detection of…

Computer Vision and Pattern Recognition · Computer Science 2019-05-31 Manpreet Singh Minhas , John Zelek
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