English
Related papers

Related papers: NVAE-GAN Based Approach for Unsupervised Time Seri…

200 papers

While anomaly detection in time series has been an active area of research for several years, most recent approaches employ an inadequate evaluation criterion leading to an inflated F1 score. We show that a rudimentary Random Guess method…

Machine Learning · Computer Science 2022-03-11 Keval Doshi , Shatha Abudalou , Yasin Yilmaz

Unsupervised learning of anomaly detection in high-dimensional data, such as images, is a challenging problem recently subject to intense research. Through careful modelling of the data distribution of normal samples, it is possible to…

Computer Vision and Pattern Recognition · Computer Science 2019-11-21 Amanda Berg , Jörgen Ahlberg , Michael Felsberg

Transformer-based models for anomaly detection in multivariate time series can benefit from the self-attention mechanism due to its advantage in modeling long-term dependencies. However, Transformer-based anomaly detection models have…

Machine Learning · Computer Science 2023-12-05 Jie Liu , Qilin Li , Senjian An , Bradley Ezard , Ling Li

Unsupervised anomaly detection in time series is essential in industrial applications, as it significantly reduces the need for manual intervention. Multivariate time series pose a complex challenge due to their feature and temporal…

Machine Learning · Computer Science 2024-08-26 Zhe Liu , Xiang Huang , Jingyun Zhang , Zhifeng Hao , Li Sun , Hao Peng

This work introduces a novel method for enhancing confidence in anomaly detection in Intrusion Detection Systems (IDS) through the use of a Variational Autoencoder (VAE) architecture. By developing a confidence metric derived from latent…

Cryptography and Security · Computer Science 2024-09-24 Ioannis Pitsiorlas , George Arvanitakis , Marios Kountouris

Most of the data-driven approaches applied to bearing fault diagnosis up to date are established in the supervised learning paradigm, which usually requires a large set of labeled data collected a priori. In practical applications, however,…

Machine Learning · Computer Science 2019-12-10 Shen Zhang , Fei Ye , Bingnan Wang , Thomas G. Habetler

Variational Auto-Encoder (VAE) has become the de-facto learning paradigm in achieving representation learning and generation for natural language at the same time. Nevertheless, existing VAE-based language models either employ elementary…

Computation and Language · Computer Science 2022-11-22 Haoqin Tu , Zhongliang Yang , Jinshuai Yang , Yongfeng Huang

Time series anomaly detection (TSAD) has gained significant attention due to its real-world applications to improve the stability of modern software systems. However, there is no effective way to verify whether they can meet the…

Forecasting anomalies (anomaly prediction) in multivariate time series from different real-world, dynamic, and complex systems is vital for preempting critical failures, leading to a substantial minimization in operational costs and human…

Time-series anomaly detection is a popular topic in both academia and industrial fields. Many companies need to monitor thousands of temporal signals for their applications and services and require instant feedback and alerts for potential…

Machine Learning · Computer Science 2020-09-10 Yuanxiang Ying , Juanyong Duan , Chunlei Wang , Yujing Wang , Congrui Huang , Bixiong Xu

The recent rise in deep learning technologies fueled innovation and boosted scientific research. Their achievements enabled new research directions for deep generative modeling (DGM), an increasingly popular approach that can create novel…

Machine Learning · Computer Science 2022-04-28 Luca Bergamin , Tommaso Carraro , Mirko Polato , Fabio Aiolli

In machine learning, novelty detection is the task of identifying novel unseen data. During training, only samples from the normal class are available. Test samples are classified as normal or abnormal by assignment of a novelty score. Here…

Recently, a generative variational autoencoder (VAE) has been proposed for speech enhancement to model speech statistics. However, this approach only uses clean speech in the training phase, making the estimation particularly sensitive to…

Audio and Speech Processing · Electrical Eng. & Systems 2021-05-18 Huajian Fang , Guillaume Carbajal , Stefan Wermter , Timo Gerkmann

Deep generative models have achieved impressive success in recent years. Generative Adversarial Networks (GANs) and Variational Autoencoders (VAEs), as emerging families for generative model learning, have largely been considered as two…

Machine Learning · Computer Science 2018-07-12 Zhiting Hu , Zichao Yang , Ruslan Salakhutdinov , Eric P. Xing

Unsupervised detection of anomaly points in time series is a challenging problem, which requires the model to derive a distinguishable criterion. Previous methods tackle the problem mainly through learning pointwise representation or…

Machine Learning · Computer Science 2022-06-30 Jiehui Xu , Haixu Wu , Jianmin Wang , Mingsheng Long

Variational auto-encoders (VAEs) provide an attractive solution to image generation problem. However, they tend to produce blurred and over-smoothed images due to their dependence on pixel-wise reconstruction loss. This paper introduces a…

Computer Vision and Pattern Recognition · Computer Science 2018-04-30 Salman H. Khan , Munawar Hayat , Nick Barnes

We propose a completely unsupervised pixel-wise anomaly detection method for hyperspectral images. The proposed method consists of three steps called data preparation, reconstruction, and detection. In the data preparation step, we apply a…

Image and Video Processing · Electrical Eng. & Systems 2021-01-25 Sertac Arisoy , Nasser M. Nasrabadi , Koray Kayabol

Benchmarking anomaly detection approaches for multivariate time series is a challenging task due to a lack of high-quality datasets. Current publicly available datasets are too small, not diverse and feature trivial anomalies, which hinders…

Machine Learning · Computer Science 2025-11-13 Lucas Correia , Jan-Christoph Goos , Thomas Bäck , Anna V. Kononova

The goal of anomaly detection is to identify examples that deviate from normal or expected behavior. We tackle this problem for images. We consider a two-phase approach. First, using normal examples, a convolutional autoencoder (CAE) is…

Computer Vision and Pattern Recognition · Computer Science 2020-03-20 Natasa Sarafijanovic-Djukic , Jesse Davis

Variational autoencoders (VAEs) are widely used deep generative models capable of learning unsupervised latent representations of data. Such representations are often difficult to interpret or control. We consider the problem of…

Machine Learning · Computer Science 2018-12-18 Jack Klys , Jake Snell , Richard Zemel