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Self-supervised learning has achieved remarkable success in learning visual representations from clean data, yet remains challenging when clean observations are sparse or not available at all. In this paper, we demonstrate that pretrained…

Computer Vision and Pattern Recognition · Computer Science 2026-04-27 Konstantinos Alexis , Giorgos Giannopoulos , Dimitrios Gunopulos

Designing appropriate variational regularization schemes is a crucial part of solving inverse problems, making them better-posed and guaranteeing that the solution of the associated optimization problem satisfies desirable properties.…

Machine Learning · Computer Science 2020-06-09 Ronan Fablet , Lucas Drumetz , Francois Rousseau

Deep metric learning maps visually similar images onto nearby locations and visually dissimilar images apart from each other in an embedding manifold. The learning process is mainly based on the supplied image negative and positive training…

Computer Vision and Pattern Recognition · Computer Science 2020-09-14 Chang-Hui Liang , Wan-Lei Zhao , Run-Qing Chen

Data assimilation combines prior (or background) information with observations to estimate the initial state of a dynamical system over a given time-window. A common application is in numerical weather prediction where a previous forecast…

Optimization and Control · Mathematics 2021-07-27 Coralia Cartis , Maha H. Kaouri , Amos S. Lawless , Nancy K. Nichols

Adaptive inference is a promising technique to improve the computational efficiency of deep models at test time. In contrast to static models which use the same computation graph for all instances, adaptive networks can dynamically adjust…

Computer Vision and Pattern Recognition · Computer Science 2019-08-20 Hao Li , Hong Zhang , Xiaojuan Qi , Ruigang Yang , Gao Huang

For many years, strongly and weakly constrained approaches were the only options to deal with errors in four-dimensional variational data assimilation (4DVar), with the aim of balancing the degrees of freedom and model constraints. Strong…

Atmospheric and Oceanic Physics · Physics 2022-12-21 Xiangjun Tian , Hongqin Zhang , Zhe Jin , Min Zhao , Yilong Wang , Yinhai Luo , Ziqing Zhang , Yanyan Tan

Policies for partially observed Markov decision processes can be efficiently learned by imitating policies for the corresponding fully observed Markov decision processes. Unfortunately, existing approaches for this kind of imitation…

Machine Learning · Computer Science 2021-07-02 Andrew Warrington , J. Wilder Lavington , Adam Ścibior , Mark Schmidt , Frank Wood

Humans can often predict physical outcomes after only a few observations, a capability known as physical intuition. The mechanisms underlying this efficient learning remain elusive. Here, we introduce a variational learning framework in…

Computational Physics · Physics 2026-03-19 Jingruo Peng , Shuze Zhu

Visual Inertial Odometry (VIO) is one of the most established state estimation methods for mobile platforms. However, when visual tracking fails, VIO algorithms quickly diverge due to rapid error accumulation during inertial data…

Robotics · Computer Science 2023-06-13 Russell Buchanan , Varun Agrawal , Marco Camurri , Frank Dellaert , Maurice Fallon

Variational data assimilation and machine-learning based super-resolution are two alternative approaches to state estimation in turbulent flows. The former is an optimisation problem featuring a time series of coarse observations, the…

Fluid Dynamics · Physics 2025-10-21 Markus Weyrauch , Moritz Linkmann , Jacob Page

Four-dimensional weak-constraint variational data assimilation estimates a state given partial noisy observations and dynamical model by minimizing a cost function that takes into account both discrepancy between the state and observations…

Dynamical Systems · Mathematics 2023-04-13 Nazanin Abedini , Svetlana Dubinkina

Volume Rendering is an important technique for visualizing three-dimensional scalar data grids and is commonly employed for scientific and medical image data. Direct Volume Rendering (DVR) is a well established and efficient rendering…

Graphics · Computer Science 2021-06-11 Jakob Weiss , Nassir Navab

A Transformer-based deep direct sampling method is proposed for electrical impedance tomography, a well-known severely ill-posed nonlinear boundary value inverse problem. A real-time reconstruction is achieved by evaluating the learned…

Machine Learning · Computer Science 2023-03-07 Ruchi Guo , Shuhao Cao , Long Chen

Much of recent Deep Reinforcement Learning success is owed to the neural architecture's potential to learn and use effective internal representations of the world. While many current algorithms access a simulator to train with a large…

Artificial Intelligence · Computer Science 2022-02-03 Amir Ardalan Kalantari , Mohammad Amini , Sarath Chandar , Doina Precup

Data assimilation is the process to fuse information from priors, observations of nature, and numerical models, in order to obtain best estimates of the parameters or state of a physical system of interest. Presence of large errors in some…

Numerical Analysis · Mathematics 2015-11-06 Vishwas Rao , Adrian Sandu , Michael Ng , Elias Nino-Ruiz

In this article we develop further an algorithm for data assimilation based upon a shadowing refinement technique [de Leeuw et al., SIAM J. Appl. Dyn. Sys., 17 (2018)] to take partial observations into account. Our method is based on…

Optimization and Control · Mathematics 2020-11-13 Bart de Leeuw , Svetlana Dubinkina

We consider the general class of time-homogeneous stochastic dynamical systems, both discrete and continuous, and study the problem of learning a representation of the state that faithfully captures its dynamics. This is instrumental to…

Machine Learning · Computer Science 2024-03-15 Vladimir R. Kostic , Pietro Novelli , Riccardo Grazzi , Karim Lounici , Massimiliano Pontil

The four-dimensional variational data assimilation (4D-Var) has emerged as an important methodology, widely used in numerical weather prediction, oceanographic modeling, and climate forecasting. Classical unconstrained gradient-based…

Numerical Analysis · Mathematics 2024-10-08 Bowen Li , Bin Shi

Data Assimilation is the process in which we improve the representation of the state of a physical system by combining information coming from a numerical model, real-world observations, and some prior modelling. It is widely used to model…

Optimization and Control · Mathematics 2025-01-09 Victor Trappler , Arthur Vidard

This paper develops a computational framework for optimizing the parameters of data assimilation systems in order to improve their performance. The approach formulates a continuous meta-optimization problem for parameters; the…

Computational Engineering, Finance, and Science · Computer Science 2015-06-16 Alexandru Cioaca , Adrian Sandu