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Convolutional Neural Network (CNN) techniques have proven to be very useful in image-based anomaly detection applications. CNN can be used as deep features extractor where other anomaly detection techniques are applied on these features.…

Machine Learning · Computer Science 2022-08-15 Sulaiman Aburakhia , Tareq Tayeh , Ryan Myers , Abdallah Shami

High-dimensional data poses unique challenges in outlier detection process. Most of the existing algorithms fail to properly address the issues stemming from a large number of features. In particular, outlier detection algorithms perform…

Machine Learning · Computer Science 2020-09-22 Firuz Kamalov , Ho Hon Leung

We introduce a powerful student-teacher framework for the challenging problem of unsupervised anomaly detection and pixel-precise anomaly segmentation in high-resolution images. Student networks are trained to regress the output of a…

Computer Vision and Pattern Recognition · Computer Science 2020-09-08 Paul Bergmann , Michael Fauser , David Sattlegger , Carsten Steger

Data sampling is an effective method to improve the training speed of neural networks, with recent results demonstrating that it can even break the neural scaling laws. These results critically rely on high-quality scores to estimate the…

Machine Learning · Computer Science 2023-11-23 Shabnam Daghaghi , Benjamin Coleman , Benito Geordie , Anshumali Shrivastava

Most classification algorithms used in high energy physics fall under the category of supervised machine learning. Such methods require a training set containing both signal and background events and are prone to classification errors…

Data Analysis, Statistics and Probability · Physics 2015-06-03 Mikael Kuusela , Tommi Vatanen , Eric Malmi , Tapani Raiko , Timo Aaltonen , Yoshikazu Nagai

We leverage recent breakthroughs in neural density estimation to propose a new unsupervised anomaly detection technique (ANODE). By estimating the probability density of the data in a signal region and in sidebands, and interpolating the…

High Energy Physics - Phenomenology · Physics 2020-05-12 Benjamin Nachman , David Shih

In practice, machine learning methods commonly require anomaly detection (AD) to filter inputs or detect distributional shifts. Typically, this is implemented by running a separate AD model alongside the primary model. However, this…

Machine Learning · Computer Science 2026-03-19 Luca Hinkamp , Simon Klüttermann , Emmanuel Müller

In many signal processing applications, including communications, sonar, radar, and localization, a fundamental problem is the detection of a signal of interest in background noise, known as signal detection [1] [2]. A simple version of…

Signal Processing · Electrical Eng. & Systems 2025-12-16 Tom Anders , Hiten Prakash Kothari , R. Michael Buehrer

Deep neural networks are known to be vulnerable to unseen data: they may wrongly assign high confidence stcores to out-distribuion samples. Recent works try to solve the problem using representation learning methods and specific metrics. In…

Computer Vision and Pattern Recognition · Computer Science 2022-06-07 Haowei He , Jiaye Teng , Yang Yuan

We address the problem of learning an unknown smooth function and its derivatives from noisy pointwise evaluations under the supremum norm. While classical nonparametric regression provides a strong theoretical foundation, traditional…

Machine Learning · Computer Science 2026-03-10 Davide Maran , Marcello Restelli

Automatic anomaly detection is a major issue in various areas. Beyond mere detection, the identification of the origin of the problem that produced the anomaly is also essential. This paper introduces a general methodology that can assist…

Machine Learning · Statistics 2014-09-17 Tsirizo Rabenoro , Jérôme Lacaille , Marie Cottrell , Fabrice Rossi

Anomaly detection is the process of identifying abnormal instances or events in data sets which deviate from the norm significantly. In this study, we propose a signatures based machine learning algorithm to detect rare or unexpected items…

Computational Finance · Quantitative Finance 2022-02-09 Erdinc Akyildirim , Matteo Gambara , Josef Teichmann , Syang Zhou

The HDoutliers algorithm is a powerful unsupervised algorithm for detecting anomalies in high-dimensional data, with a strong theoretical foundation. However, it suffers from some limitations that significantly hinder its performance level,…

Machine Learning · Statistics 2019-08-13 Priyanga Dilini Talagala , Rob J. Hyndman , Kate Smith-Miles

This paper presents a new approach, based on polynomial optimization and the method of moments, to the problem of anomaly detection. The proposed technique only requires information about the statistical moments of the normal-state…

Optimization and Control · Mathematics 2015-06-02 Jose A. Lopez , Octavia Camps , Mario Sznaier

Given an inhomogeneous chain embedded in a noisy image, we consider the conditions under which such an embedded chain is detectable. Many applications, such as detecting moving objects, detecting ship wakes, can be abstracted as the…

Statistics Theory · Mathematics 2020-09-22 Kai Ni , Shanshan Cao , Xiaoming Huo

In order to detect unknown intrusions and runtime errors of computer programs, the cyber-security community has developed various detection techniques. Anomaly detection is an approach that is designed to profile the normal runtime behavior…

Cryptography and Security · Computer Science 2021-06-03 Byunggu Yu , Junwhan Kim

K-nearest neighbors (KNN) is one of the earliest and most established algorithms in machine learning. For regression tasks, KNN averages the targets within a neighborhood which poses a number of challenges: the neighborhood definition is…

Machine Learning · Computer Science 2022-05-18 Youssef Nader , Leon Sixt , Tim Landgraf

This paper studies a stylized, yet natural, learning-to-rank problem and points out the critical incorrectness of a widely used nearest neighbor algorithm. We consider a model with $n$ agents (users) $\{x_i\}_{i \in [n]}$ and $m$…

Machine Learning · Computer Science 2018-07-11 Ao Liu , Qiong Wu , Zhenming Liu , Lirong Xia

kNN is a very effective Instance based learning method, and it is easy to implement. Due to heterogeneous nature of data, noises from different possible sources are also widespread in nature especially in case of large-scale databases. For…

Machine Learning · Computer Science 2020-05-19 Joydip Dhar , Ashaya Shukla , Mukul Kumar , Prashant Gupta

The goal of anomaly detection is to identify anomalous samples from normal ones. In this paper, a small number of anomalies are assumed to be available at the training stage, but they are assumed to be collected only from several anomaly…

Machine Learning · Computer Science 2022-05-03 Bowen Tian , Qinliang Su , Jian Yin