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Related papers: Sequential Outlier Detection in Non-Stationary Tim…

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Unsupervised anomaly detection in time-series has been extensively investigated in the literature. Notwithstanding the relevance of this topic in numerous application fields, a comprehensive and extensive evaluation of recent…

Machine Learning · Computer Science 2024-08-13 Nesryne Mejri , Laura Lopez-Fuentes , Kankana Roy , Pavel Chernakov , Enjie Ghorbel , Djamila Aouada

A sensor network is considered where at each sensor a sequence of random variables is observed. At each time step, a processed version of the observations is transmitted from the sensors to a common node called the fusion center. At some…

Statistics Theory · Mathematics 2023-07-19 Taposh Banerjee , Venugopal V. Veeravalli

This paper presents a practical approach for detecting non-stationarity in time series prediction. This method is called SAFE and works by monitoring the evolution of the spectral contents of time series through a distance function. This…

Machine Learning · Computer Science 2018-05-18 Arief Koesdwiady , Fakhri Karray

Outlier detection is a fundamental task in data mining and has many applications including detecting errors in databases. While there has been extensive prior work on methods for outlier detection, modern datasets often have sizes that are…

Machine Learning · Computer Science 2019-08-01 Laure Berti-Equille , Ji Meng Loh , Saravanan Thirumuruganathan

This work proposes an unsupervised learning framework for trajectory (sequence) outlier detection that combines ranking tests with user sequence models. The overall framework identifies sequence outliers at a desired false positive rate…

Machine Learning · Computer Science 2021-11-09 Mohamed A. Zahran , Leonardo Teixeira , Vinayak Rao , Bruno Ribeiro

This paper presents a new approach for detecting outliers by introducing the notion of object's proximity. The main idea is that normal point has similar characteristics with several neighbors. So the point in not an outlier if it has a…

Computer Vision and Pattern Recognition · Computer Science 2014-11-26 Amina Dik , Khalid Jebari , Abdelaziz Bouroumi , Aziz Ettouhami

Many machine learning classification systems lack competency awareness. Specifically, many systems lack the ability to identify when outliers (e.g., samples that are distinct from and not represented in the training data distribution) are…

Machine Learning · Computer Science 2020-07-03 Matthew Cook , Alina Zare , Paul Gader

An outlier is an observation or a data point that is far from rest of the data points in a given dataset or we can be said that an outlier is away from the center of mass of observations. Presence of outliers can skew statistical measures…

Machine Learning · Computer Science 2021-06-17 Amulya Agarwal , Nitin Gupta

We propose a new assumption in outlier detection: Normal data instances are commonly located in the area that there is hardly any fluctuation on data density, while outliers are often appeared in the area that there is violent fluctuation…

Machine Learning · Computer Science 2020-06-09 Ding Liu , Hui Li

Sequential detection of independent anomalous processes among K processes is considered. At each time, only M processes can be observed, and the observations from each chosen process follow two different distributions, depending on whether…

Information Theory · Computer Science 2023-07-19 Kobi Cohen , Qing Zhao

The article describes a practical method for detecting outlier database connections in real-time. Outlier connections are detected with a specified level of confidence. The method is based on generalized security rules and a simple but…

Databases · Computer Science 2025-01-15 Leonid Rodniansky , Tania Butovsky , Mikhail Shpak

Aleatoric and Epistemic uncertainty have achieved recent attention in the literature as different sources from which uncertainty can emerge in stochastic modeling. Epistemic being intrinsic or model based notions of uncertainty, and…

Methodology · Statistics 2025-08-15 Ryan Warnick

This article develops a method to construct the optimal sequential test for monitoring the changes in the distribution of finite observation sequences with a general dependence structure. This method allows us to prove that different…

Statistics Theory · Mathematics 2019-08-01 Dong Han , Fugee Tsung , Jinguo Xian

The non-stationary evolution of observable quantities in complex systems can frequently be described as a juxtaposition of quasi-stationary spells. Given that standard theoretical and data analysis approaches usually rely on the assumption…

Statistical Mechanics · Physics 2011-10-18 S. Camargo , S. Duarte Queirós , C. Anteneodo

The purpose of this paper is to construct a new non-parametric detector of univariate outliers and to study its asymptotic properties. This detector is based on a Hill's type statistic. It satisfies a unique asymptotic behavior for a large…

Statistics Theory · Mathematics 2017-05-04 Jean-Marc Bardet , Solohaja-Faniaha Dimby

Out-of-distribution detection (OOD) deals with anomalous input to neural networks. In the past, specialized methods have been proposed to reject predictions on anomalous input. Similarly, it was shown that feature extraction models in…

Machine Learning · Computer Science 2022-01-25 Jan Diers , Christian Pigorsch

We propose a probabilistic formulation that enables sequential detection of multiple change points in a network setting. We present a class of sequential detection rules for certain functionals of change points (minimum among a subset), and…

Statistics Theory · Mathematics 2012-07-09 Arash Ali Amini , XuanLong Nguyen

Observations in data which are significantly different from its neighbouring points but cannot be classified as noise are known as anomalies or outliers. These anomalies are a cause of concern and a timely warning about their presence could…

Applications · Statistics 2020-06-09 Krishnam Kapoor

We consider novelty detection in time series with unknown and nonparametric probability structures. A deep learning approach is proposed to causally extract an innovations sequence consisting of novelty samples statistically independent of…

Machine Learning · Computer Science 2022-10-25 Xinyi Wang , Mei-jen Lee , Qing Zhao , Lang Tong

For a long time, research on time series anomaly detection has mainly focused on finding outliers within a given time series. Admittedly, this is consistent with some practical problems, but in other practical application scenarios, people…

Machine Learning · Computer Science 2024-02-06 Hanxu Zhou , Yuan Zhang , Guangjie Leng , Ruofan Wang , Zhi-Qin John Xu