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Related papers: Deep Contrastive One-Class Time Series Anomaly Det…

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As an exemplary self-supervised approach for representation learning, time-series contrastive learning has exhibited remarkable advancements in contemporary research. While recent contrastive learning strategies have focused on how to…

Machine Learning · Computer Science 2024-08-27 Xiyuan Jin , Jing Wang , Lei Liu , Youfang Lin

Many methods have been proposed for unsupervised time series anomaly detection. Despite some progress, research on predicting future anomalies is still relatively scarce. Predicting anomalies is particularly challenging due to the diverse…

Machine Learning · Computer Science 2024-10-22 Shiyan Hu , Kai Zhao , Xiangfei Qiu , Yang Shu , Jilin Hu , Bin Yang , Chenjuan Guo

Recently, anomaly scores have been formulated using reconstruction loss of the adversarially learned generators and/or classification loss of discriminators. Unavailability of anomaly examples in the training data makes optimization of such…

Computer Vision and Pattern Recognition · Computer Science 2024-10-28 Muhammad Zaigham Zaheer , Jin Ha Lee , Arif Mahmood , Marcella Astrid , Seung-Ik Lee

Unified anomaly detection (AD) is one of the most challenges for anomaly detection, where one unified model is trained with normal samples from multiple classes with the objective to detect anomalies in these classes. For such a challenging…

Machine Learning · Computer Science 2024-07-08 Xincheng Yao , Ruoqi Li , Zefeng Qian , Lu Wang , Chongyang Zhang

Contrastive learning methods enforce label distance relationships in feature space to improve representation capability for regression models. However, these methods highly depend on label information to correctly recover ordinal…

Machine Learning · Computer Science 2025-12-11 Ce Wang , Weihang Dai , Hanru Bai , Xiaomeng Li

Graph anomaly detection (GAD) has attracted increasing attention in machine learning and data mining. Recent works have mainly focused on how to capture richer information to improve the quality of node embeddings for GAD. Despite their…

Machine Learning · Computer Science 2023-10-03 Jingcan Duan , Pei Zhang , Siwei Wang , Jingtao Hu , Hu Jin , Jiaxin Zhang , Haifang Zhou , Xinwang Liu

Classical approaches for one-class problems such as one-class SVM and isolation forest require careful feature engineering when applied to structured domains like images. State-of-the-art methods aim to leverage deep learning to learn…

Machine Learning · Computer Science 2020-08-18 Sachin Goyal , Aditi Raghunathan , Moksh Jain , Harsha Vardhan Simhadri , Prateek Jain

Neural network-based anomaly detection methods have shown to achieve high performance. However, they require a large amount of training data for each task. We propose a neural network-based meta-learning method for supervised anomaly…

Machine Learning · Statistics 2021-03-02 Tomoharu Iwata , Atsutoshi Kumagai

Anomaly Detection in multivariate time series is a major problem in many fields. Due to their nature, anomalies sparsely occur in real data, thus making the task of anomaly detection a challenging problem for classification algorithms to…

Machine Learning · Computer Science 2023-08-08 Anastasios Iliopoulos , John Violos , Christos Diou , Iraklis Varlamis

Anomaly detection on time series data is increasingly common across various industrial domains that monitor metrics in order to prevent potential accidents and economic losses. However, a scarcity of labeled data and ambiguous definitions…

Machine Learning · Computer Science 2022-12-29 Lawrence Wong , Dongyu Liu , Laure Berti-Equille , Sarah Alnegheimish , Kalyan Veeramachaneni

The superiority of graph contrastive learning (GCL) has prompted its application to anomaly detection tasks for more powerful risk warning systems. Unfortunately, existing GCL-based models tend to excessively prioritize overall detection…

Machine Learning · Computer Science 2025-07-22 Yiming Xu , Zhen Peng , Bin Shi , Xu Hua , Bo Dong , Song Wang , Chen Chen

Clustering is the task of gathering similar data samples into clusters without using any predefined labels. It has been widely studied in machine learning literature, and recent advancements in deep learning have revived interest in this…

Machine Learning · Computer Science 2023-09-04 Mohammadreza Sadeghi , Hadi Hojjati , Narges Armanfard

Selective classification enables models to make predictions only when they are sufficiently confident, aiming to enhance safety and reliability, which is important in high-stakes scenarios. Previous methods mainly use deep neural networks…

Machine Learning · Computer Science 2024-06-10 Yu-Chang Wu , Shen-Huan Lyu , Haopu Shang , Xiangyu Wang , Chao Qian

This study reveals the inherent tolerance of contrastive learning (CL) towards sampling bias, wherein negative samples may encompass similar semantics (\eg labels). However, existing theories fall short in providing explanations for this…

Machine Learning · Computer Science 2023-10-18 Junkang Wu , Jiawei Chen , Jiancan Wu , Wentao Shi , Xiang Wang , Xiangnan He

Unsupervised object discovery (UOD) refers to the task of discriminating the whole region of objects from the background within a scene without relying on labeled datasets, which benefits the task of bounding-box-level localization and…

Computer Vision and Pattern Recognition · Computer Science 2023-07-10 Yunqiu Lv , Jing Zhang , Nick Barnes , Yuchao Dai

Contrastive learning is a well-established paradigm in representation learning. The standard framework of contrastive learning minimizes the distance between "similar" instances and maximizes the distance between dissimilar ones in the…

Machine Learning · Computer Science 2025-02-06 Naghmeh Ghanooni , Barbod Pajoum , Harshit Rawal , Sophie Fellenz , Vo Nguyen Le Duy , Marius Kloft

The goal of contrastive learning based pre-training is to leverage large quantities of unlabeled data to produce a model that can be readily adapted downstream. Current approaches revolve around solving an image discrimination task: given…

Computer Vision and Pattern Recognition · Computer Science 2021-11-30 Chenhongyi Yang , Lichao Huang , Elliot J. Crowley

Graph Neural Networks (GNNs) have become popular in Graph Representation Learning (GRL). One fundamental application is few-shot node classification. Most existing methods follow the meta learning paradigm, showing the ability of fast…

Machine Learning · Computer Science 2023-09-20 Hao Liu , Jiarui Feng , Lecheng Kong , Dacheng Tao , Yixin Chen , Muhan Zhang

Using deep learning techniques, anomalies in the paranasal sinus system can be detected automatically in MRI images and can be further analyzed and classified based on their volume, shape and other parameters like local contrast. However…

A significant threat to the recent, wide deployment of machine learning-based systems, including deep neural networks (DNNs), is adversarial learning attacks. We analyze possible test-time evasion-attack mechanisms and show that, in some…

Machine Learning · Computer Science 2018-06-29 David J. Miller , Yulia Wang , George Kesidis