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Gaussian graphical models (GGM) have been widely used in many high-dimensional applications ranging from biological and financial data to recommender systems. Sparsity in GGM plays a central role both statistically and computationally.…

Machine Learning · Statistics 2014-06-12 Zhaoshi Meng , Brian Eriksson , Alfred O. Hero

Generative models based on variational autoencoders are a popular technique for detecting anomalies in images in a semi-supervised context. A common approach employs the anomaly score to detect the presence of anomalies, and it is known to…

Machine Learning · Computer Science 2024-07-30 Muhammad Rashid , Elvio Amparore , Enrico Ferrari , Damiano Verda

We consider the consistency properties of a regularised estimator for the simultaneous identification of both changepoints and graphical dependency structure in multivariate time-series. Traditionally, estimation of Gaussian Graphical…

Statistics Theory · Mathematics 2017-12-18 Alex J. Gibberd , Sandipan Roy

Conditional Gaussian graphical models (cGGM) are a recent reparametrization of the multivariate linear regression model which explicitly exhibits $i)$ the partial covariances between the predictors and the responses, and $ii)$ the partial…

Methodology · Statistics 2014-09-26 Julien Chiquet , Tristan Mary-Huard , Stéphane Robin

The time-series anomaly detection is one of the most fundamental tasks for time-series. Unlike the time-series forecasting and classification, the time-series anomaly detection typically requires unsupervised (or self-supervised) training…

Machine Learning · Computer Science 2023-08-30 Haksoo Lim , Sewon Park , Minjung Kim , Jaehoon Lee , Seonkyu Lim , Noseong Park

Anomaly detection in multivariate time series is a central challenge in industrial monitoring, as failures frequently arise from complex temporal dynamics and cross-sensor interactions. While recent deep learning models, including graph…

Machine Learning · Computer Science 2026-04-21 Pooyan Khosravinia , João Gama , Bruno Veloso

Registering accurately point clouds from a cheap low-resolution sensor is a challenging task. Existing rigid registration methods failed to use the physical 3D uncertainty distribution of each point from a real sensor in the dynamic…

Computer Vision and Pattern Recognition · Computer Science 2018-08-03 Can Pu , Nanbo Li , Radim Tylecek , Robert B Fisher

Anomaly detection in multivariate time series (MTS) is hindered by dynamic inter-variable dependencies and feature entanglement under spectral noise, and in practice, is further complicated by the absence of anomaly labels. Existing…

Machine Learning · Computer Science 2026-05-25 Yunhua Pei , Zixing Song , Jin Zheng , John Cartlidge

Estimation of Gaussian graphical models is important in natural science when modeling the statistical relationships between variables in the form of a graph. The sparsity and clustering structure of the concentration matrix is enforced to…

Optimization and Control · Mathematics 2020-04-20 Meixia Lin , Defeng Sun , Kim-Chuan Toh , Chengjing Wang

Graph contrastive learning (GCL), learning the node representation by contrasting two augmented graphs in a self-supervised way, has attracted considerable attention. GCL is usually believed to learn the invariant representation. However,…

Machine Learning · Computer Science 2024-03-08 Yanhu Mo , Xiao Wang , Shaohua Fan , Chuan Shi

Gaussian graphical models are used for determining conditional relationships between variables. This is accomplished by identifying off-diagonal elements in the inverse-covariance matrix that are non-zero. When the ratio of variables (p) to…

Applications · Statistics 2018-08-07 Donald R. Williams , Juho Piironen , Aki Vehtari , Philippe Rast

Reactive anomaly detection methods, which are commonly deployed to identify anomalies after they occur based on observed deviations, often fall short in applications that demand timely intervention, such as industrial monitoring, finance,…

Machine Learning · Computer Science 2026-02-13 Luis Olmos , Rashida Hasan

Gaussian Graphical Models (GGMs) have wide-ranging applications in machine learning and the natural and social sciences. In most of the settings in which they are applied, the number of observed samples is much smaller than the dimension…

Machine Learning · Computer Science 2020-03-10 Jonathan Kelner , Frederic Koehler , Raghu Meka , Ankur Moitra

Anomalies can be defined as any non-random structure which deviates from normality. Anomaly detection methods reported in the literature are numerous and diverse, as what is considered anomalous usually varies depending on particular…

Computer Vision and Pattern Recognition · Computer Science 2021-10-07 Matias Tailanian , Pablo Musé , Álvaro Pardo

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

This paper addresses the challenges of complex dependencies and diverse anomaly patterns in cloud service environments by proposing a dependency modeling and anomaly detection method that integrates contrastive learning. The method…

Machine Learning · Computer Science 2025-10-16 Yue Xing , Yingnan Deng , Heyao Liu , Ming Wang , Yun Zi , Xiaoxuan Sun

Gaussian graphical models (GGMs) are widely used for statistical modeling, because of ease of inference and the ubiquitous use of the normal distribution in practical approximations. However, they are also known for their limited modeling…

Machine Learning · Statistics 2016-11-22 Qinliang Su , Xuejun Liao , Chunyuan Li , Zhe Gan , Lawrence Carin

Anomaly detection from graph data has drawn much attention due to its practical significance in many critical applications including cybersecurity, finance, and social networks. Existing data mining and machine learning methods are either…

Machine Learning · Computer Science 2022-01-25 Yu Zheng , Ming Jin , Yixin Liu , Lianhua Chi , Khoa T. Phan , Yi-Ping Phoebe Chen

Anomaly detection in imbalanced datasets is a frequent and crucial problem, especially in the medical domain where retrieving and labeling irregularities is often expensive. By combining the generative stability of a $\beta$-variational…

Machine Learning · Computer Science 2023-10-30 Fiete Lüer , Tobias Weber , Maxim Dolgich , Christian Böhm

Graphical models are widely used in scienti fic and engineering research to represent conditional independence structures between random variables. In many controlled experiments, environmental changes or external stimuli can often alter…

Machine Learning · Computer Science 2012-03-19 Bai Zhang , Yue Wang