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Related papers: Anomaly Detection via Graphical Lasso

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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

Weighted Outlier Detection is a method for identifying unusual or anomalous data points in a dataset, which can be caused by various factors like human error, fraud, or equipment malfunctions. Detecting outliers can reveal vital information…

Machine Learning · Computer Science 2023-06-13 Ravindrakumar Purohit , Jai Prakash Verma , Rachna Jain , Madhuri Bhavsar

This work addresses the problem of graph learning from data following a Gaussian Graphical Model (GGM) with a time-varying mean. Graphical Lasso (GL), the standard method for estimating sparse precision matrices, assumes that the observed…

Machine Learning · Computer Science 2025-03-26 Samuel Rey , Ernesto Curbelo , Luca Martino , Fernando Llorente , Antonio G. Marques

Anomaly detection, a critical facet in data analysis, involves identifying patterns that deviate from expected behavior. This research addresses the complexities inherent in anomaly detection, exploring challenges and adapting to…

Machine Learning · Computer Science 2024-05-07 Aditya Singh , Pavan Reddy

In the fields of statistics and unsupervised machine learning a fundamental and well-studied problem is anomaly detection. Anomalies are difficult to define, yet many algorithms have been proposed. Underlying the approaches is the nebulous…

Cryptography and Security · Computer Science 2022-05-16 Nassir Mohammad

Many applications in data analysis rely on the decomposition of a data matrix into a low-rank and a sparse component. Existing methods that tackle this task use the nuclear norm and L1-cost functions as convex relaxations of the rank…

Machine Learning · Statistics 2013-01-18 Clemens Hage , Martin Kleinsteuber

Anomaly detection algorithms are often thought to be limited because they don't facilitate the process of validating results performed by domain experts. In Contrast, deep learning algorithms for anomaly detection, such as autoencoders,…

Machine Learning · Computer Science 2020-07-02 Liat Antwarg , Ronnie Mindlin Miller , Bracha Shapira , Lior Rokach

Anomaly detection is being regarded as an unsupervised learning task as anomalies stem from adversarial or unlikely events with unknown distributions. However, the predictive performance of purely unsupervised anomaly detection often fails…

Machine Learning · Computer Science 2014-01-27 Nico Goernitz , Marius Micha Kloft , Konrad Rieck , Ulf Brefeld

Outliers are the points which are different from or inconsistent with the rest of the data. They can be novel, new, abnormal, unusual or noisy information. Outliers are sometimes more interesting than the majority of the data. The main…

Computer Vision and Pattern Recognition · Computer Science 2014-06-20 Singh Vijendra , Pathak Shivani

Anomaly detection refers to the task of finding unusual instances that stand out from the normal data. In several applications, these outliers or anomalous instances are of greater interest compared to the normal ones. Specifically in the…

Image and Video Processing · Electrical Eng. & Systems 2020-01-14 Manpreet Singh Minhas , John Zelek

It is well-known that the statistical performance of Lasso can suffer significantly when the covariates of interest have strong correlations. In particular, the prediction error of Lasso becomes much worse than computationally inefficient…

Machine Learning · Statistics 2024-02-26 Jonathan Kelner , Frederic Koehler , Raghu Meka , Dhruv Rohatgi

Multivariate time-series anomaly detection is essential for reliable industrial control, telemetry, and service monitoring. However, the evolving inter-variable dependencies and inevitable noise render it challenging. Existing methods often…

Machine Learning · Computer Science 2026-02-25 Zhongpeng Qi , Jun Zhang , Wei Li , Zhuoxuan Liang

The precision matrix that encodes conditional linear dependency relations among a set of variables forms an important object of interest in multivariate analysis. Sparse estimation procedures for precision matrices such as the graphical…

Methodology · Statistics 2023-03-09 Gaëtan Louvet , Jakob Raymaekers , Germain Van Bever , Ines Wilms

This paper considers an anomaly detection problem in which a detection algorithm assigns anomaly scores to multi-dimensional data points, such as cellular networks' Key Performance Indicators (KPIs). We propose an optimization framework to…

Information Theory · Computer Science 2023-09-01 Ali Maatouk , Fadhel Ayed , Wenjie Li , Yu Wang , Hong Zhu , Jiantao Ye

Anomaly detection on dynamic graphs refers to detecting entities whose behaviors obviously deviate from the norms observed within graphs and their temporal information. This field has drawn increasing attention due to its application in…

Machine Learning · Computer Science 2023-10-26 Shiqi Lou , Qingyue Zhang , Shujie Yang , Yuyang Tian , Zhaoxuan Tan , Minnan Luo

This paper introduces a novel anomaly detection framework that combines the robust statistical principles of density-estimation-based anomaly detection methods with the representation-learning capabilities of deep learning models. The…

Machine Learning · Computer Science 2024-08-15 Joseph Gallego-Mejia , Oscar Bustos-Brinez , Fabio A. González

Gaussian Graphical Models (GGMs) are widely used in high-dimensional data analysis to synthesize the interaction between variables. In many applications, such as genomics or image analysis, graphical models rely on sparsity and clustering…

Machine Learning · Statistics 2026-03-25 Do Edmond Sanou , Christophe Ambroise , Geneviève Robin

Google uses continuous streams of data from industry partners in order to deliver accurate results to users. Unexpected drops in traffic can be an indication of an underlying issue and may be an early warning that remedial action may be…

Machine Learning · Statistics 2017-08-15 Dominique T. Shipmon , Jason M. Gurevitch , Paolo M. Piselli , Stephen T. Edwards

Robust regression models in the presence of outliers have significant practical relevance in areas such as signal processing, financial econometrics, and energy management. Many existing robust regression methods, either grounded in…

Signal Processing · Electrical Eng. & Systems 2025-06-30 Pengyang Song , Jue Wang

Anomaly detection is the process of finding data points that deviate from a baseline. In a real-life setting, anomalies are usually unknown or extremely rare. Moreover, the detection must be accomplished in a timely manner or the risk of…

Machine Learning · Computer Science 2019-04-26 Mariem Ben Fadhel , Kofi Nyarko