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A Vector Auto-Regressive (VAR) model is commonly used to model multivariate time series, and there are many penalized methods to handle high dimensionality. However in terms of spatio-temporal data, most methods do not take the spatial and…

Methodology · Statistics 2020-12-21 Zhenzhong Wang , Abolfazl Safikhani , Zhengyuan Zhu , David S. Matteson

High-speed boundary-layer transition is extremely sensitive to the free-stream disturbances which are often uncertain. This uncertainty compromises predictions of models and simulations. To enhance the fidelity of simulations, we directly…

Fluid Dynamics · Physics 2021-04-28 David A. Buchta , Tamer A. Zaki

Phase-averaging is a fundamental approach for investigating periodic and non-stationary phenomena. In fluid dynamics, these can be generated by rotating blades such as propellers/turbines or by pulsed jets. Traditional phase-averaging…

Fluid Dynamics · Physics 2025-02-20 Enrico Amico , Sara Montagner , Jacopo Serpieri , Gioacchino Cafiero

Data assimilation (DA) is a fundamental component of modern weather prediction, yet it remains a major computational bottleneck in machine learning (ML)-based forecasting pipelines due to reliance on traditional variational methods. Recent…

Machine Learning · Computer Science 2026-02-09 Ran Cheng , Lailai Zhu

State estimation in multi-layer turbulent flow fields with only a single layer of partial observation remains a challenging yet practically important task. Applications include inferring the state of the deep ocean by exploiting surface…

Fluid Dynamics · Physics 2025-09-30 Zhongrui Wang , Nan Chen , Di Qi

The problem of broad practical interest in spatiotemporal data analysis, i.e., discovering interpretable dynamic patterns from spatiotemporal data, is studied in this paper. Towards this end, we develop a time-varying reduced-rank vector…

Machine Learning · Computer Science 2022-11-29 Xinyu Chen , Chengyuan Zhang , Xiaoxu Chen , Nicolas Saunier , Lijun Sun

Coherent wide parameter-space searches for continuous gravitational waves are typically limited in sensitivity by their prohibitive computing cost. Therefore semi-coherent methods (such as StackSlide) can often achieve a better sensitivity.…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Reinhard Prix , Miroslav Shaltev

Observability can determine which recorded variables of a given system are optimal for discriminating its different states. Quantifying observability requires knowledge of the equations governing the dynamics. These equations are often…

Adaptation and Self-Organizing Systems · Physics 2020-10-28 Christopher E. Gonzalez , Claudia Lainscsek , Terrence J. Sejnowski , Christophe Letellier

The dynamic mode decomposition (DMD) has become a leading tool for data-driven modeling of dynamical systems, providing a regression framework for fitting linear dynamical models to time-series measurement data. We present a simple…

Numerical Analysis · Mathematics 2017-04-11 Travis Askham , J. Nathan Kutz

Accurate prediction of shallow water flows relies on precise bottom topography data, yet direct bathymetric surveys are expensive and time-consuming. In contrast, remote sensing platforms such as radar or satellite altimetry provide…

Numerical Analysis · Mathematics 2026-03-13 Falko Ruppenthal , Dmitri Kuzmin

In multivariate time series, the estimation of the covariance matrix of the observation innovations plays an important role in forecasting as it enables the computation of the standardized forecast error vectors as well as it enables the…

Methodology · Statistics 2008-02-04 K. Triantafyllopoulos

We consider the problem of forecasting complex, nonlinear space-time processes when observations provide only partial information of on the system's state. We propose a natural data-driven framework, where the system's dynamics are modelled…

Systems and Control · Computer Science 2019-03-01 Ibrahim Ayed , Emmanuel de Bézenac , Arthur Pajot , Julien Brajard , Patrick Gallinari

Out-of-Distribution (OOD) detection is essential for the trustworthiness of AI systems. Methods using prior information (i.e., subspace-based methods) have shown effective performance by extracting information geometry to detect OOD data…

Computer Vision and Pattern Recognition · Computer Science 2025-06-25 Kaiyu Guo , Zijian Wang , Tan Pan , Brian C. Lovell , Mahsa Baktashmotlagh

We propose a modification of a maximum likelihood procedure for tuning parameter values in models, based upon the comparison of their output to field data. Our methodology, which uses polynomial approximations of the sample space to…

Data Analysis, Statistics and Probability · Physics 2013-07-03 Nusret Balci , Juan M. Restrepo , Shankar C. Venkataramani

We formulate a depth-averaged non-hydrostatic model to solve wave equations with generation by a moving bottom. This model is built upon the shallow water equations, which are widely used in tsunami wave modelling. An extension leads to two…

Numerical Analysis · Mathematics 2025-03-11 Kemal Firdaus , Jörn Behrens

A novel method is proposed for detecting changes in the covariance structure of moderate dimensional time series. This non-linear test statistic has a number of useful properties. Most importantly, it is independent of the underlying…

Methodology · Statistics 2021-08-18 Sean Ryan , Rebecca Killick

Understanding the motion states of the surrounding environment is critical for safe autonomous driving. These motion states can be accurately derived from scene flow, which captures the three-dimensional motion field of points. Existing…

Computer Vision and Pattern Recognition · Computer Science 2024-07-12 Jaeyeul Kim , Jungwan Woo , Ukcheol Shin , Jean Oh , Sunghoon Im

Balanced truncation is a well-established model order reduction method which has been applied to a variety of problems. Recently, a connection between linear Gaussian Bayesian inference problems and the system-theoretic concept of balanced…

Numerical Analysis · Mathematics 2024-01-04 Josie König , Melina A. Freitag

Data assimilation (DA) plays a pivotal role in numerical weather prediction by systematically integrating sparse observations with model forecasts to estimate optimal atmospheric initial condition for forthcoming forecasts. Traditional…

Atmospheric and Oceanic Physics · Physics 2025-10-28 Jing-An Sun , Hang Fan , Junchao Gong , Ben Fei , Kun Chen , Fenghua Ling , Wenlong Zhang , Wanghan Xu , Li Yan , Pierre Gentine , Lei Bai

As climate change increases the threat of weather-related disasters, research on weather control is gaining importance. The objective of weather control is to mitigate disaster risks by administering interventions with optimal timing,…

Atmospheric and Oceanic Physics · Physics 2025-05-19 Yuta Higuchi , Rikuto Nagai , Atsushi Okazaki , Masaki Ogura , Naoki Wakamiya