Search Results for author: Themistoklis Sapsis

Found 8 papers, 6 papers with code

A non-intrusive machine learning framework for debiasing long-time coarse resolution climate simulations and quantifying rare events statistics

no code implementations28 Feb 2024 Benedikt Barthel Sorensen, Alexis Charalampopoulos, Shixuan Zhang, Bryce Harrop, Ruby Leung, Themistoklis Sapsis

To overcome this challenge, we introduce a dynamical systems approach where the correction operator is trained using reference data and a coarse model simulation nudged towards that reference.

A Multi-Scale Deep Learning Framework for Projecting Weather Extremes

no code implementations21 Oct 2022 Antoine Blanchard, Nishant Parashar, Boyko Dodov, Christian Lessig, Themistoklis Sapsis

Weather extremes are a major societal and economic hazard, claiming thousands of lives and causing billions of dollars in damage every year.

Output-weighted and relative entropy loss functions for deep learning precursors of extreme events

1 code implementation1 Dec 2021 Samuel Rudy, Themistoklis Sapsis

One cause for this difficulty is that systems with extreme events, by definition, yield imbalanced datasets and that standard loss functions easily ignore rare events.

Output-Weighted Sampling for Multi-Armed Bandits with Extreme Payoffs

1 code implementation19 Feb 2021 Yibo Yang, Antoine Blanchard, Themistoklis Sapsis, Paris Perdikaris

We present a new type of acquisition functions for online decision making in multi-armed and contextual bandit problems with extreme payoffs.

Decision Making Gaussian Processes +1

Output-Weighted Optimal Sampling for Bayesian Experimental Design and Uncertainty Quantification

1 code implementation22 Jun 2020 Antoine Blanchard, Themistoklis Sapsis

We introduce a class of acquisition functions for sample selection that leads to faster convergence in applications related to Bayesian experimental design and uncertainty quantification.

Active Learning Experimental Design +1

Informative Path Planning for Extreme Anomaly Detection in Environment Exploration and Monitoring

1 code implementation20 May 2020 Antoine Blanchard, Themistoklis Sapsis

An unmanned autonomous vehicle (UAV) is sent on a mission to explore and reconstruct an unknown environment from a series of measurements collected by Bayesian optimization.

Anomaly Detection Bayesian Optimization

Bayesian Optimization with Output-Weighted Optimal Sampling

1 code implementation22 Apr 2020 Antoine Blanchard, Themistoklis Sapsis

In Bayesian optimization, accounting for the importance of the output relative to the input is a crucial yet challenging exercise, as it can considerably improve the final result but often involves inaccurate and cumbersome entropy estimations.

Bayesian Optimization

Generative stochastic modeling of strongly nonlinear flows with non-Gaussian statistics

1 code implementation20 Aug 2019 Hassan Arbabi, Themistoklis Sapsis

As such, this framework represents the chaotic time series as the evolution of a stochastic system observed through the lens of a nonlinear map.

Dynamical Systems Chaotic Dynamics 62G32, 76F20, 49Q22, 60G10

Cannot find the paper you are looking for? You can Submit a new open access paper.