Search Results for author: Leonardo Zepeda-Núñez

Found 15 papers, 4 papers with code

Dynamical-generative downscaling of climate model ensembles

no code implementations2 Oct 2024 Ignacio Lopez-Gomez, Zhong Yi Wan, Leonardo Zepeda-Núñez, Tapio Schneider, John Anderson, Fei Sha

Regional high-resolution climate projections are crucial for many applications, such as agriculture, hydrology, and natural hazard risk assessment.

Climate Projection

Generative AI for fast and accurate Statistical Computation of Fluids

no code implementations27 Sep 2024 Roberto Molinaro, Samuel Lanthaler, Bogdan Raonić, Tobias Rohner, Victor Armegioiu, Zhong Yi Wan, Fei Sha, Siddhartha Mishra, Leonardo Zepeda-Núñez

We present a generative AI algorithm for addressing the challenging task of fast, accurate and robust statistical computation of three-dimensional turbulent fluid flows.

Operator learning

Back-Projection Diffusion: Solving the Wideband Inverse Scattering Problem with Diffusion Models

no code implementations5 Aug 2024 Borong Zhang, Martín Guerra, Qin Li, Leonardo Zepeda-Núñez

We present Wideband back-projection diffusion, an end-to-end probabilistic framework for approximating the posterior distribution induced by the inverse scattering map from wideband scattering data.

A probabilistic framework for learning non-intrusive corrections to long-time climate simulations from short-time training data

no code implementations2 Aug 2024 Benedikt Barthel Sorensen, Leonardo Zepeda-Núñez, Ignacio Lopez-Gomez, Zhong Yi Wan, Rob Carver, Fei Sha, Themistoklis Sapsis

In this work we present a general strategy for training neural network models to non-intrusively correct under-resolved long-time simulations of chaotic systems.

DySLIM: Dynamics Stable Learning by Invariant Measure for Chaotic Systems

1 code implementation6 Feb 2024 Yair Schiff, Zhong Yi Wan, Jeffrey B. Parker, Stephan Hoyer, Volodymyr Kuleshov, Fei Sha, Leonardo Zepeda-Núñez

Learning dynamics from dissipative chaotic systems is notoriously difficult due to their inherent instability, as formalized by their positive Lyapunov exponents, which exponentially amplify errors in the learned dynamics.

User-defined Event Sampling and Uncertainty Quantification in Diffusion Models for Physical Dynamical Systems

no code implementations13 Jun 2023 Marc Finzi, Anudhyan Boral, Andrew Gordon Wilson, Fei Sha, Leonardo Zepeda-Núñez

In this work, we develop a probabilistic approximation scheme for the conditional score function which provably converges to the true distribution as the noise level decreases.

Uncertainty Quantification

Debias Coarsely, Sample Conditionally: Statistical Downscaling through Optimal Transport and Probabilistic Diffusion Models

1 code implementation NeurIPS 2023 Zhong Yi Wan, Ricardo Baptista, Yi-fan Chen, John Anderson, Anudhyan Boral, Fei Sha, Leonardo Zepeda-Núñez

Moreover, our procedure correctly matches the statistics of physical quantities, even when the low-frequency content of the inputs and outputs do not match, a crucial but difficult-to-satisfy assumption needed by current state-of-the-art alternatives.

Evolve Smoothly, Fit Consistently: Learning Smooth Latent Dynamics For Advection-Dominated Systems

no code implementations25 Jan 2023 Zhong Yi Wan, Leonardo Zepeda-Núñez, Anudhyan Boral, Fei Sha

We present a data-driven, space-time continuous framework to learn surrogate models for complex physical systems described by advection-dominated partial differential equations.

Learning to correct spectral methods for simulating turbulent flows

2 code implementations1 Jul 2022 Gideon Dresdner, Dmitrii Kochkov, Peter Norgaard, Leonardo Zepeda-Núñez, Jamie A. Smith, Michael P. Brenner, Stephan Hoyer

We build upon Fourier-based spectral methods, which are known to be more efficient than other numerical schemes for simulating PDEs with smooth and periodic solutions.

BIG-bench Machine Learning

Accurate and Robust Deep Learning Framework for Solving Wave-Based Inverse Problems in the Super-Resolution Regime

no code implementations2 Jun 2021 Matthew Li, Laurent Demanet, Leonardo Zepeda-Núñez

We propose an end-to-end deep learning framework that comprehensively solves the inverse wave scattering problem across all length scales.

Super-Resolution

Wide-band butterfly network: stable and efficient inversion via multi-frequency neural networks

no code implementations24 Nov 2020 Matthew Li, Laurent Demanet, Leonardo Zepeda-Núñez

We introduce an end-to-end deep learning architecture called the wide-band butterfly network (WideBNet) for approximating the inverse scattering map from wide-band scattering data.

Efficient Long-Range Convolutions for Point Clouds

1 code implementation11 Oct 2020 Yifan Peng, Lin Lin, Lexing Ying, Leonardo Zepeda-Núñez

We showcase this framework by introducing a neural network architecture that combines LRC-layers with short-range convolutional layers to accurately learn the energy and force associated with a $N$-body potential.

Learning the mapping $\mathbf{x}\mapsto \sum_{i=1}^d x_i^2$: the cost of finding the needle in a haystack

no code implementations24 Feb 2020 Jiefu Zhang, Leonardo Zepeda-Núñez, Yuan YAO, Lin Lin

When such structural information is not available, and we may only use a dense neural network, the optimization procedure to find the sparse network embedded in the dense network is similar to finding the needle in a haystack, using a given number of samples of the function.

Deep Density: circumventing the Kohn-Sham equations via symmetry preserving neural networks

no code implementations27 Nov 2019 Leonardo Zepeda-Núñez, Yixiao Chen, Jiefu Zhang, Weile Jia, Linfeng Zhang, Lin Lin

By directly targeting at the self-consistent electron density, we demonstrate that the adapted network architecture, called the Deep Density, can effectively represent the electron density as the linear combination of contributions from many local clusters.

Translation

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