English
Related papers

Related papers: LUNAR: Unifying Local Outlier Detection Methods vi…

200 papers

We propose a one-class neural network (OC-NN) model to detect anomalies in complex data sets. OC-NN combines the ability of deep networks to extract a progressively rich representation of data with the one-class objective of creating a…

Machine Learning · Computer Science 2019-01-14 Raghavendra Chalapathy , Aditya Krishna Menon , Sanjay Chawla

A key component of many graph neural networks (GNNs) is the pooling operation, which seeks to reduce the size of a graph while preserving important structural information. However, most existing graph pooling strategies rely on an…

Machine Learning · Computer Science 2023-10-17 Mahsa Mesgaran , A. Ben Hamza

Graph anomaly detection (GAD) is a vital task since even a few anomalies can pose huge threats to benign users. Recent semi-supervised GAD methods, which can effectively leverage the available labels as prior knowledge, have achieved…

Machine Learning · Computer Science 2023-06-21 Shuang Zhou , Xiao Huang , Ninghao Liu , Huachi Zhou , Fu-Lai Chung , Long-Kai Huang

Graph anomaly detection (GAD) is a vital task since even a few anomalies can pose huge threats to benign users. Recent semi-supervised GAD methods, which can effectively leverage the available labels as prior knowledge, have achieved…

Machine Learning · Computer Science 2023-07-25 Shuang Zhou , Xiao Huang , Ninghao Liu , Fu-Lai Chung , Long-Kai Huang

Graph Neural Networks (GNNs) and their message passing framework that leverages both structural and feature information, have become a standard method for solving graph-based machine learning problems. However, these approaches still…

Machine Learning · Computer Science 2024-11-20 Simon Delarue , Thomas Bonald , Tiphaine Viard

Outlier detection (also known as anomaly detection or deviation detection) is a process of detecting data points in which their patterns deviate significantly from others. It is common to have outliers in industry applications, which could…

Machine Learning · Computer Science 2019-11-06 Kasra Babaei , ZhiYuan Chen , Tomas Maul

Many computer vision tasks involve processing large amounts of data contaminated by outliers, which need to be detected and rejected. While outlier detection methods based on robust statistics have existed for decades, only recently have…

Computer Vision and Pattern Recognition · Computer Science 2017-04-14 Chong You , Daniel P. Robinson , René Vidal

Anomalies represent rare observations (e.g., data records or events) that deviate significantly from others. Over several decades, research on anomaly mining has received increasing interests due to the implications of these occurrences in…

Machine Learning · Computer Science 2022-04-21 Xiaoxiao Ma , Jia Wu , Shan Xue , Jian Yang , Chuan Zhou , Quan Z. Sheng , Hui Xiong , Leman Akoglu

Detecting unusual patterns in graph data is a crucial task in data mining. However, existing methods face challenges in consistently achieving satisfactory performance and often lack interpretability, which hinders our understanding of…

Machine Learning · Computer Science 2024-06-28 Yifei Yang , Peng Wang , Xiaofan He , Dongmian Zou

We apply several machine learning algorithms to the problem of anomaly detection in operational data for large-scale, high-voltage electric power grids. We observe important differences in the performance of the algorithms. Neural networks…

Systems and Control · Electrical Eng. & Systems 2026-02-12 Marc Gillioz , Guillaume Dubuis , Étienne Voutaz , Philippe Jacquod

Anomaly detection in graph-structured data is an inherently challenging problem, as it requires the identification of rare nodes that deviate from the majority in both their structural and behavioral characteristics. Existing methods, such…

Machine Learning · Computer Science 2025-09-16 Mingkang Li , Xuexiong Luo , Yue Zhang , Yaoyang Li , Fu Lin

Anomaly detection is referred to as a process in which the aim is to detect data points that follow a different pattern from the majority of data points. Anomaly detection methods suffer from several well-known challenges that hinder their…

Machine Learning · Computer Science 2021-08-31 Kasra Babaei , Zhi Yuan Chen , Tomas Maul

When neural networks are employed for high-stakes decision-making, it is desirable that they provide explanations for their prediction in order for us to understand the features that have contributed to the decision. At the same time, it is…

Machine Learning · Computer Science 2022-05-10 Penny Chong , Ngai-Man Cheung , Yuval Elovici , Alexander Binder

Anomaly detection aims to detect abnormal events by a model of normality. It plays an important role in many domains such as network intrusion detection, criminal activity identity and so on. With the rapidly growing size of accessible…

Machine Learning · Computer Science 2018-08-02 Chu Wang , Yan-Ming Zhang , Cheng-Lin Liu

Dynamic graph anomaly detection (DGAD) is critical for many real-world applications but remains challenging due to the scarcity of labeled anomalies. Existing methods are either unsupervised or semi-supervised: unsupervised methods avoid…

Machine Learning · Computer Science 2026-02-24 Yuxing Tian , Yiyan Qi , Fengran Mo , Weixu Zhang , Jian Guo , Jian-Yun Nie

A critical aspect of Graph Neural Networks (GNNs) is to enhance the node representations by aggregating node neighborhood information. However, when detecting anomalies, the representations of abnormal nodes are prone to be averaged by…

Machine Learning · Computer Science 2024-07-03 Chunjing Xiao , Shikang Pang , Xovee Xu , Xuan Li , Goce Trajcevski , Fan Zhou

Due to the veracity and heterogeneity in network traffic, detecting anomalous events is challenging. The computational load on global servers is a significant challenge in terms of efficiency, accuracy, and scalability. Our primary…

Machine Learning · Computer Science 2023-03-15 William Marfo , Deepak K. Tosh , Shirley V. Moore

Graph-level anomaly detection aims to identify abnormal graphs that exhibit deviant structures and node attributes compared to the majority in a graph set. One primary challenge is to learn normal patterns manifested in both fine-grained…

Machine Learning · Computer Science 2023-07-04 Chaoxi Niu , Guansong Pang , Ling Chen

The ability to selectively remove knowledge from LLMs is highly desirable. However, existing methods often struggle with balancing unlearning efficacy and retain model utility, and lack controllability at inference time to emulate base…

Machine Learning · Computer Science 2025-10-09 William F. Shen , Xinchi Qiu , Meghdad Kurmanji , Alex Iacob , Lorenzo Sani , Yihong Chen , Nicola Cancedda , Nicholas D. Lane

This study proposes a risk pricing anomaly detection method for social network user portraits based on graph neural networks (GNNs), aiming to improve the ability to identify abnormal users in social network environments. In view of the…

Machine Learning · Computer Science 2025-03-26 Yiwei Zhang