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We use a simulation study to compare three methods for adaptive experimentation: Thompson sampling, Tempered Thompson sampling, and Exploration sampling. We gauge the performance of each in terms of social welfare and estimation accuracy,…

Methodology · Statistics 2022-07-05 Samantha Horn , Sabina J. Sloman

A deep learning (DL) model, based on a transformer architecture, is trained on a climate-model dataset and compared with a standard linear inverse model (LIM) in the tropical Pacific. We show that the DL model produces more accurate…

Atmospheric and Oceanic Physics · Physics 2024-06-12 Zilu Meng , Gregory J. Hakim

We describe a new approach based on tropical optimization techniques to solve the problem of rating alternatives from pairwise comparison data. The problem is formulated to approximate, in the log-Chebyshev sense, pairwise comparison…

Optimization and Control · Mathematics 2016-12-12 N. Krivulin

We propose, analyze, and test a novel continuous data assimilation reduced order model (DA-ROM) for simulating incompressible flows. While ROMs have a long history of success on certain problems with recurring dominant structures, they tend…

Numerical Analysis · Mathematics 2019-10-02 Camille Zerfas , Leo G. Rebholz , Michael Schneier , Traian Iliescu

Engineering simulations are usually based on complex, grid-based, or mesh-free methods for solving partial differential equations. The results of these methods cover large fields of physical quantities at very many discrete spatial…

Fluid Dynamics · Physics 2025-08-08 Eduardo Di Costanzo , Niklas Kühl , Jean-Christophe Marongiu , Thomas Rung

Deep learning has recently gained attention in the atmospheric and oceanic sciences for its potential to improve the accuracy of numerical simulations or to reduce computational costs. Super-resolution is one such technique for…

Atmospheric and Oceanic Physics · Physics 2023-09-21 Yuki Yasuda , Ryo Onishi

A 4D-Var data assimilation technique is applied to a ORCA-2 configuration of the NEMO in order to identify the optimal parametrization of the boundary conditions on the lateral boundaries as well as on the bottom and on the surface of the…

Atmospheric and Oceanic Physics · Physics 2015-06-12 Eugene Kazantsev

We present the mathematical framework of a Domain Decomposition (DD) aproach based on Parallel-in-Time methods (PinT-based approach) for solving the 4D-Var Data Assimilation (DA) model. The main outcome of the proposed DD PinT-based…

Numerical Analysis · Mathematics 2018-07-20 Luisa D'Amore , Rosalba Cacciapuoti

Data assimilation combines forecasts from a numerical model with observations. Most of the current data assimilation algorithms consider the model and observation error terms as additive Gaussian noise, specified by their covariance…

``Online" data assimilation (DA) is used to generate a new seasonal-resolution reanalysis dataset over the last millennium by combining forecasts from an ocean--atmosphere--sea-ice coupled linear inverse model with climate proxy records.…

Atmospheric and Oceanic Physics · Physics 2025-01-27 Zilu Meng , Gregory J. Hakim , Eric J. Steig

Estimating output changes by input changes is the main task in causal analysis. In previous work, input and output Self-Organizing Maps (SOMs) were associated for causal analysis of multivariate and nonlinear data. Based on the association,…

Computer Vision and Pattern Recognition · Computer Science 2017-03-28 Younjin Chung , Joachim Gudmundsson , Masahiro Takatsuka

Using a very cheap Data Assimilation (DA) method, I show an alternative approach to classical DA for numerical climate models which produce a large amount of "big data". The problematic features of state-of-the-art high resolution Regional…

Applications · Statistics 2016-10-12 Bijan Fallah

Most of existing correlation filter-based tracking approaches only estimate simple axis-aligned bounding boxes, and very few of them is capable of recovering the underlying similarity transformation. To tackle this challenging problem, in…

Computer Vision and Pattern Recognition · Computer Science 2018-11-08 Yang Li , Jianke Zhu , Steven C. H. Hoi , Wenjie Song , Zhefeng Wang , Hantang Liu

Continuous data assimilation (CDA) is a method that continuously integrates observational data into a dynamical system to improve model accuracy in real-time. The AOT algorithm is one of the most widely used methods in CDA due to its…

Optimization and Control · Mathematics 2024-07-25 Ning Ning , Collin Victor

Dynamic downscaling typically involves using numerical weather prediction (NWP) solvers to refine coarse data to higher spatial resolutions. Data-driven models such as FourCastNet have emerged as a promising alternative to the traditional…

Atmospheric and Oceanic Physics · Physics 2025-03-05 Philip Dinenis , Vishwas Rao , Mihai Anitescu

Algorithms for data assimilation try to predict the most likely state of a dynamical system by combining information from observations and prior models. Variational approaches, such as the weak-constraint four-dimensional variational data…

Numerical Analysis · Mathematics 2023-04-05 Davide Palitta , Jemima M. Tabeart

Variance reduction techniques are designed to decrease the sampling variance, thereby accelerating convergence rates of first-order (FO) and zeroth-order (ZO) optimization methods. However, in composite optimization problems, ZO methods…

Machine Learning · Computer Science 2024-05-29 Hao Di , Haishan Ye , Yueling Zhang , Xiangyu Chang , Guang Dai , Ivor W. Tsang

The Strong Constraint 4D Variational (SC-4DVAR) data assimilation method is widely used in climate and weather applications. SC-4DVAR involves solving a minimization problem to compute the maximum a posteriori estimate, which we tackle…

Numerical Analysis · Mathematics 2025-06-16 Amit N. Subrahmanya , Vishwas Rao , Arvind K. Saibaba

Understanding local currents in the North Atlantic region of the ocean is a key part of modelling heat transfer and global climate patterns. Satellites provide a surface signature of the temperature of the ocean with a high horizontal…

Atmospheric and Oceanic Physics · Physics 2019-10-22 Gautier Cosne , Guillaume Maze , Pierre Tandeo

Data assimilation combines information from physical observations and numerical simulation results to obtain better estimates of the state and parameters of a physical system. A wide class of physical systems of interest have solutions that…

Optimization and Control · Mathematics 2025-05-02 Amit N. Subrahmanya , Adrian Sandu