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We introduce the notion, and develop the theory of local-noise spectroscopy (LNS) - a tool to study the properties of systems far from equilibrium by means of flux density correlations. As a test bed, we apply it to biased molecular…

Mesoscale and Nanoscale Physics · Physics 2019-02-11 Gabriel Cabra , Massimiliano Di Ventra , Michael Galperin

A method for unsupervised contextual anomaly detection is proposed using a cross-linked pair of Variational Auto-Encoders for assigning a normality score to an observation. The method enables a distinct separation of contextual from…

Machine Learning · Statistics 2019-04-02 Yaniv Shulman

The detection of anomalies in multivariate time series data is crucial for various practical applications, including smart power grids, traffic flow forecasting, and industrial process control. However, real-world time series data is…

Machine Learning · Computer Science 2024-01-12 Yu Zheng , Huan Yee Koh , Ming Jin , Lianhua Chi , Haishuai Wang , Khoa T. Phan , Yi-Ping Phoebe Chen , Shirui Pan , Wei Xiang

This article introduces a nonparametric approach to spectral analysis of a high-dimensional multivariate nonstationary time series. The procedure is based on a novel frequency-domain factor model that provides a flexible yet parsimonious…

Methodology · Statistics 2019-10-29 Zeda Li , Ori Rosen , Fabio Ferrarelli , Robert T. Krafty

We address the problem of measuring nonclassicality in continuous-variable bosonic systems without having access to a known reference signal. To this end, we construct broader classes of criteria for nonclassicality which allow us to…

This paper investigates the signal detection problem in colored Gaussian noise with an unknown covariance matrix. To be specific, we consider a sample deficient scenario in which the number of signal bearing samples ($n$) is strictly…

Signal Processing · Electrical Eng. & Systems 2024-04-26 Prathapasinghe Dharmawansa , Saman Atapattu , Jamie Evans , Kandeepan Sithamparanathan

We describe a method for modeling spatial context to enable video anomaly detection. The main idea is to discover regions that share similar object-level activities by clustering joint object attributes using Gaussian mixture models. We…

Computer Vision and Pattern Recognition · Computer Science 2025-01-16 Zhengye Yang , Richard J. Radke

We study the regularity properties of Gaussian fields defined over spheres cross time. In particular, we consider two alternative spectral decompositions for a Gaussian field on $\mathbb{S}^d \times \mathbb{R}$. For each decomposition, we…

Probability · Mathematics 2018-01-25 Jorge Clarke de La Cerda , Alfredo Alegría , Emilio Porcu , Jorge De La Cerda

In numerous applications data are observed at random times and an estimated graph of the spectral density may be relevant for characterizing and explaining phenomena. By using a wavelet analysis, one derives a nonparametric estimator of the…

Statistics Theory · Mathematics 2009-11-27 Jean-Marc Bardet , Pierre Bertrand

The Laplacian eigenvalues of a network play an important role in the analysis of many structural and dynamical network problems. In this paper, we study the relationship between the eigenvalue spectrum of the normalized Laplacian matrix and…

Social and Information Networks · Computer Science 2013-10-21 Zhengwei Wu , Victor M. Preciado

We introduce a scalable approach to Gaussian process inference that combines spatio-temporal filtering with natural gradient variational inference, resulting in a non-conjugate GP method for multivariate data that scales linearly with…

Machine Learning · Computer Science 2021-11-03 Oliver Hamelijnck , William J. Wilkinson , Niki A. Loppi , Arno Solin , Theodoros Damoulas

Gaussian Boson Sampling (GBS) is a quantum computing concept based on drawing samples from a multimode nonclassical Gaussian state using photon-number resolving detectors. It was initially posed as a near-term approach aiming to achieve…

Quantum Physics · Physics 2022-06-22 S. Sempere-Llagostera , R. B. Patel , I. A. Walmsley , W. S. Kolthammer

We consider the change-point detection problem of deciding, based on noisy measurements, whether an unknown signal over a given graph is constant or is instead piecewise constant over two connected induced subgraphs of relatively low cut…

Statistics Theory · Mathematics 2012-06-06 James Sharpnack , Alessandro Rinaldo , Aarti Singh

Both sampling a time-varying signal, and its spectral analysis are activities subjected to theoretically compelling, such as Shannon's theorem and the objectively limiting of the frequency's resolution. Usually, the signals' spectra are…

Numerical Analysis · Computer Science 2015-05-25 Cezar Doca , Constantin Paunoiu

This paper proposes a novel feature called spectrum congruency for describing edges in images. The spectrum congruency is a generalization of the phase congruency, which depicts how much each Fourier components of the image are congruent in…

Image and Video Processing · Electrical Eng. & Systems 2021-03-11 Fang Yang , Xin Su , Li Chai

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

Gaussian random number generators attract a widespread interest due to their applications in several fields. Important requirements include easy implementation, tail accuracy, and, finally, a flat spectrum. In this work, we study the…

Information Theory · Computer Science 2024-04-04 Francisco-Javier Soto , Ana I. Gómez , Domingo Gómez-Pérez

In independent component analysis it is assumed that the observed random variables are linear combinations of latent, mutually independent random variables called the independent components. Our model further assumes that only the…

Statistics Theory · Mathematics 2016-12-19 Joni Virta , Klaus Nordhausen , Hannu Oja

Multivariate time series data come as a collection of time series describing different aspects of a certain temporal phenomenon. Anomaly detection in this type of data constitutes a challenging problem yet with numerous applications in…

Artificial Intelligence · Computer Science 2025-11-12 Jinbo Li , Hesam Izakian , Witold Pedrycz , Iqbal Jamal

We present a novel Bayesian approach to analysing multiple time-series with the aim of detecting abnormal regions. These are regions where the properties of the data change from some normal or baseline behaviour. We allow for the…

Applications · Statistics 2015-08-17 Lawrence Bardwell , Paul Fearnhead