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Related papers: HLSAD: Hodge Laplacian-based Simplicial Anomaly De…

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Graph Anomaly Detection (GAD) aims to identify uncommon, deviated, or suspicious objects within graph-structured data. Existing methods generally focus on a single graph object type (node, edge, graph, etc.) and often overlook the inherent…

Machine Learning · Computer Science 2024-11-12 Yiqing Lin , Jianheng Tang , Chenyi Zi , H. Vicky Zhao , Yuan Yao , Jia Li

This paper introduces a novel adaptive framework for processing dynamic flow signals over simplicial complexes, extending classical least-mean-squares (LMS) methods to high-order topological domains. Building on discrete Hodge theory, we…

Signal Processing · Electrical Eng. & Systems 2025-05-30 Lorenzo Marinucci , Claudio Battiloro , Paolo Di Lorenzo

Responding to the challenge of detecting unusual radar targets in a well identified environment, innovative anomaly and novelty detection methods keep emerging in the literature. This work aims at presenting a benchmark gathering common and…

Signal Processing · Electrical Eng. & Systems 2021-06-22 Martin Bauw , Santiago Velasco-Forero , Jesus Angulo , Claude Adnet , Olivier Airiau

Graph-level anomaly detection (GLAD) has already gained significant importance and has become a popular field of study, attracting considerable attention across numerous downstream works. The core focus of this domain is to capture and…

Machine Learning · Computer Science 2024-07-17 Zitong Wang , Xuexiong Luo , Enfeng Song , Qiuqing Bai , Fu Lin

Traditional anomaly detection on social media mostly focuses on individual point anomalies while anomalous phenomena usually occur in groups. Therefore it is valuable to study the collective behavior of individuals and detect group…

Machine Learning · Computer Science 2014-10-09 Qi , Yu , Xinran He , Yan Liu

Graph Convolutional Network (GCN) are widely used in Graph Anomaly Detection (GAD) due to their natural compatibility with graph structures, resulting in significant performance improvements. However, most researchers approach GAD as a…

Machine Learning · Computer Science 2024-11-05 Shelei Li , Yong Chai Tan , Tai Vincent

Detecting anomalies in link streams that represent various kinds of interactions is an important research topic with crucial applications. Because of the lack of ground truth data, proposed methods are mostly evaluated through their ability…

Machine Learning · Computer Science 2026-03-03 Matthieu Latapy , Stephany Rajeh

The absence of intrinsic adjacency relations and orientation systems in hypergraphs creates fundamental challenges for constructing sheaf Laplacians of arbitrary degrees. We resolve these limitations through symmetric simplicial sets…

Machine Learning · Computer Science 2025-08-01 Seongjin Choi , Gahee Kim , Yong-Geun Oh

Despite the vast literature on network dynamics, we still lack basic insights into dynamics on higher-order structures (e.g., edges, triangles, and more generally, $k$-dimensional "simplices") and how they are influenced through…

Physics and Society · Physics 2022-03-14 Cameron Ziegler , Per Sebastian Skardal , Haimonti Dutta , Dane Taylor

Our previous multiscale graph basis dictionaries/graph signal transforms -- Generalized Haar-Walsh Transform (GHWT); Hierarchical Graph Laplacian Eigen Transform (HGLET); Natural Graph Wavelet Packets (NGWPs); and their relatives -- were…

Social and Information Networks · Computer Science 2023-10-18 Naoki Saito , Stefan C. Schonsheck , Eugene Shvarts

Anomaly detection in dynamic graphs is a critical task with broad real-world applications, including social networks, e-commerce, and cybersecurity. Most existing methods assume that normal patterns remain stable over time; however, this…

Machine Learning · Computer Science 2025-09-23 Xiaoyang Xu , Xiaofeng Lin , Koh Takeuchi , Kyohei Atarashi , Hisashi Kashima

In the real world, anomalous entities often add more legitimate connections while hiding direct links with other anomalous entities, leading to heterophilic structures in anomalous networks that most GNN-based techniques fail to address.…

Machine Learning · Computer Science 2025-08-21 Zengyi Wo , Wenjun Wang , Minglai Shao , Chang Liu , Yumeng Wang , Yueheng Sun

Detecting anomalies in time series data is a critical task across many domains. The challenge intensifies when anomalies are sparse and the data are multivariate with relational dependencies across sensors or nodes. Traditional univariate…

Machine Learning · Computer Science 2025-03-06 Sneh Pillai

Anomaly detection in spatiotemporal data is a challenging problem encountered in a variety of applications including hyperspectral imaging, video surveillance and urban traffic monitoring. In the case of urban traffic data, anomalies refer…

Signal Processing · Electrical Eng. & Systems 2021-03-02 Seyyid Emre Sofuoglu , Selin Aviyente

Hypergraphs and simplical complexes both capture the higher-order interactions of complex systems, ranging from higher-order collaboration networks to brain networks. One open problem in the field is what should drive the choice of the…

Physics and Society · Physics 2022-09-28 Federica Baccini , Filippo Geraci , Ginestra Bianconi

Hyperspectral images (HSIs) are inevitably degraded by a mixture of various types of noise, such as Gaussian noise, impulse noise, stripe noise, and dead pixels, which greatly limits the subsequent applications. Although various denoising…

Image and Video Processing · Electrical Eng. & Systems 2024-01-12 Dongyi Li , Dong Chu , Xiaobin Guan , Wei He , Huanfeng Shen

Anomaly detection (such as telecom fraud detection and medical image detection) has attracted the increasing attention of people. The complex interaction between multiple entities widely exists in the network, which can reflect specific…

Machine Learning · Computer Science 2024-06-10 Xu Yuan , Na Zhou , Shuo Yu , Huafei Huang , Zhikui Chen , Feng Xia

Hypergraph is a data structure that enables us to model higher-order associations among data entities. Conventional graph-structured data can represent pairwise relationships only, whereas hypergraph enables us to associate any number of…

Machine Learning · Computer Science 2024-12-10 Md. Tanvir Alam , Chowdhury Farhan Ahmed , Carson K. Leung

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

Graph-level anomaly detection (GAD) describes the problem of detecting graphs that are abnormal in their structure and/or the features of their nodes, as compared to other graphs. One of the challenges in GAD is to devise graph…

Computer Vision and Pattern Recognition · Computer Science 2021-12-21 Rongrong Ma , Guansong Pang , Ling Chen , Anton van den Hengel