Stochastic Flow Matching for Resolving Small-Scale Physics

Fuente: arXiv
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Autori principali: Fotiadis, Stathi, Brenowitz, Noah, Geffner, Tomas, Cohen, Yair, Pritchard, Michael, Vahdat, Arash, Mardani, Morteza
Natura: Preprint
Pubblicazione: 2024
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author Fotiadis, Stathi
Brenowitz, Noah
Geffner, Tomas
Cohen, Yair
Pritchard, Michael
Vahdat, Arash
Mardani, Morteza
author_facet Fotiadis, Stathi
Brenowitz, Noah
Geffner, Tomas
Cohen, Yair
Pritchard, Michael
Vahdat, Arash
Mardani, Morteza
contents Conditioning diffusion and flow models have proven effective for super-resolving small-scale details in natural images.However, in physical sciences such as weather, super-resolving small-scale details poses significant challenges due to: (i) misalignment between input and output distributions (i.e., solutions to distinct partial differential equations (PDEs) follow different trajectories), (ii) multi-scale dynamics, deterministic dynamics at large scales vs. stochastic at small scales, and (iii) limited data, increasing the risk of overfitting. To address these challenges, we propose encoding the inputs to a latent base distribution that is closer to the target distribution, followed by flow matching to generate small-scale physics. The encoder captures the deterministic components, while flow matching adds stochastic small-scale details. To account for uncertainty in the deterministic part, we inject noise into the encoder output using an adaptive noise scaling mechanism, which is dynamically adjusted based on maximum-likelihood estimates of the encoder predictions. We conduct extensive experiments on both the real-world CWA weather dataset and the PDE-based Kolmogorov dataset, with the CWA task involving super-resolving the weather variables for the region of Taiwan from 25 km to 2 km scales. Our results show that the proposed stochastic flow matching (SFM) framework significantly outperforms existing methods such as conditional diffusion and flows.
format Preprint
id arxiv_https___arxiv_org_abs_2410_19814
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Stochastic Flow Matching for Resolving Small-Scale Physics
Fotiadis, Stathi
Brenowitz, Noah
Geffner, Tomas
Cohen, Yair
Pritchard, Michael
Vahdat, Arash
Mardani, Morteza
Computer Vision and Pattern Recognition
Atmospheric and Oceanic Physics
Machine Learning
Conditioning diffusion and flow models have proven effective for super-resolving small-scale details in natural images.However, in physical sciences such as weather, super-resolving small-scale details poses significant challenges due to: (i) misalignment between input and output distributions (i.e., solutions to distinct partial differential equations (PDEs) follow different trajectories), (ii) multi-scale dynamics, deterministic dynamics at large scales vs. stochastic at small scales, and (iii) limited data, increasing the risk of overfitting. To address these challenges, we propose encoding the inputs to a latent base distribution that is closer to the target distribution, followed by flow matching to generate small-scale physics. The encoder captures the deterministic components, while flow matching adds stochastic small-scale details. To account for uncertainty in the deterministic part, we inject noise into the encoder output using an adaptive noise scaling mechanism, which is dynamically adjusted based on maximum-likelihood estimates of the encoder predictions. We conduct extensive experiments on both the real-world CWA weather dataset and the PDE-based Kolmogorov dataset, with the CWA task involving super-resolving the weather variables for the region of Taiwan from 25 km to 2 km scales. Our results show that the proposed stochastic flow matching (SFM) framework significantly outperforms existing methods such as conditional diffusion and flows.
title Stochastic Flow Matching for Resolving Small-Scale Physics
topic Computer Vision and Pattern Recognition
Atmospheric and Oceanic Physics
Machine Learning
url https://arxiv.org/abs/2410.19814