Search Results for author: Kookjin Lee

Found 30 papers, 7 papers with code

Understanding and Mitigating Membership Inference Risks of Neural Ordinary Differential Equations

no code implementations12 Jan 2025 Sanghyun Hong, Fan Wu, Anthony Gruber, Kookjin Lee

By accurately learning underlying dynamics in data in the form of differential equations, NODEs have been widely adopted in various domains, such as healthcare, finance, computer vision, and language modeling.

Language Modeling Language Modelling

Physics-informed reduced order model with conditional neural fields

no code implementations6 Dec 2024 Minji Kim, Tianshu Wen, Kookjin Lee, Youngsoo Choi

This study presents the conditional neural fields for reduced-order modeling (CNF-ROM) framework to approximate solutions of parametrized partial differential equations (PDEs).

Decoder

MaD-Scientist: AI-based Scientist solving Convection-Diffusion-Reaction Equations Using Massive PINN-Based Prior Data

no code implementations9 Oct 2024 Mingu Kang, Dongseok Lee, Woojin Cho, Jaehyeon Park, Kookjin Lee, Anthony Gruber, Youngjoon Hong, Noseong Park

Large language models (LLMs), like ChatGPT, have shown that even trained with noisy prior data, they can generalize effectively to new tasks through in-context learning (ICL) and pre-training techniques.

In-Context Learning

FastLRNR and Sparse Physics Informed Backpropagation

no code implementations5 Oct 2024 Woojin Cho, Kookjin Lee, Noseong Park, Donsub Rim, Gerrit Welper

We introduce Sparse Physics Informed Backpropagation (SPInProp), a new class of methods for accelerating backpropagation for a specialized neural network architecture called Low Rank Neural Representation (LRNR).

Latent Space Energy-based Neural ODEs

no code implementations5 Sep 2024 Sheng Cheng, Deqian Kong, Jianwen Xie, Kookjin Lee, Ying Nian Wu, Yezhou Yang

This family of models generates each data point in the time series by a neural emission model, which is a non-linear transformation of a latent state vector.

MuJoCo

Parameterized Physics-informed Neural Networks for Parameterized PDEs

no code implementations18 Aug 2024 Woojin Cho, Minju Jo, Haksoo Lim, Kookjin Lee, Dongeun Lee, Sanghyun Hong, Noseong Park

Complex physical systems are often described by partial differential equations (PDEs) that depend on parameters such as the Reynolds number in fluid mechanics.

Uncertainty Quantification

Efficiently Parameterized Neural Metriplectic Systems

no code implementations25 May 2024 Anthony Gruber, Kookjin Lee, Haksoo Lim, Noseong Park, Nathaniel Trask

Metriplectic systems are learned from data in a way that scales quadratically in both the size of the state and the rank of the metriplectic data.

PAC-FNO: Parallel-Structured All-Component Fourier Neural Operators for Recognizing Low-Quality Images

no code implementations20 Feb 2024 Jinsung Jeon, Hyundong Jin, Jonghyun Choi, Sanghyun Hong, Dongeun Lee, Kookjin Lee, Noseong Park

Extensively evaluating methods with seven image recognition benchmarks, we show that the proposed PAC-FNO improves the performance of existing baseline models on images with various resolutions by up to 77. 1% and various types of natural variations in the images at inference.

All

Learning Flexible Body Collision Dynamics with Hierarchical Contact Mesh Transformer

1 code implementation19 Dec 2023 Youn-Yeol Yu, Jeongwhan Choi, Woojin Cho, Kookjin Lee, Nayong Kim, Kiseok Chang, Chang-Seung Woo, Ilho Kim, Seok-Woo Lee, Joon-Young Yang, Sooyoung Yoon, Noseong Park

These methods are typically designed to i) reduce the computational cost in solving physical dynamics and/or ii) propose techniques to enhance the solution accuracy in fluid and rigid body dynamics.

Graph Neural Network Numerical Integration +1

Operator-learning-inspired Modeling of Neural Ordinary Differential Equations

no code implementations16 Dec 2023 Woojin Cho, Seunghyeon Cho, Hyundong Jin, Jinsung Jeon, Kookjin Lee, Sanghyun Hong, Dongeun Lee, Jonghyun Choi, Noseong Park

Neural ordinary differential equations (NODEs), one of the most influential works of the differential equation-based deep learning, are to continuously generalize residual networks and opened a new field.

Image Classification Image Generation +3

Graph Convolutions Enrich the Self-Attention in Transformers!

1 code implementation7 Dec 2023 Jeongwhan Choi, Hyowon Wi, Jayoung Kim, Yehjin Shin, Kookjin Lee, Nathaniel Trask, Noseong Park

We propose a graph-filter-based self-attention (GFSA) to learn a general yet effective one, whose complexity, however, is slightly larger than that of the original self-attention mechanism.

Clone Detection +7

Reversible and irreversible bracket-based dynamics for deep graph neural networks

1 code implementation NeurIPS 2023 Anthony Gruber, Kookjin Lee, Nathaniel Trask

Recent works have shown that physics-inspired architectures allow the training of deep graph neural networks (GNNs) without oversmoothing.

Time Series Forecasting with Hypernetworks Generating Parameters in Advance

no code implementations22 Nov 2022 Jaehoon Lee, Chan Kim, Gyumin Lee, Haksoo Lim, Jeongwhan Choi, Kookjin Lee, Dongeun Lee, Sanghyun Hong, Noseong Park

Forecasting future outcomes from recent time series data is not easy, especially when the future data are different from the past (i. e. time series are under temporal drifts).

Time Series Time Series Forecasting

Mining Causality from Continuous-time Dynamics Models: An Application to Tsunami Forecasting

no code implementations10 Oct 2022 Fan Wu, Sanghyun Hong, Donsub Rim, Noseong Park, Kookjin Lee

However, parameterization of dynamics using a neural network makes it difficult for humans to identify causal structures in the data.

Time Series Time Series Analysis

Parameter-varying neural ordinary differential equations with partition-of-unity networks

no code implementations1 Oct 2022 Kookjin Lee, Nathaniel Trask

In this study, we propose parameter-varying neural ordinary differential equations (NODEs) where the evolution of model parameters is represented by partition-of-unity networks (POUNets), a mixture of experts architecture.

Unity

AdamNODEs: When Neural ODE Meets Adaptive Moment Estimation

1 code implementation13 Jul 2022 Suneghyeon Cho, Sanghyun Hong, Kookjin Lee, Noseong Park

In this work, we propose adaptive momentum estimation neural ODEs (AdamNODEs) that adaptively control the acceleration of the classical momentum-based approach.

Computational Efficiency

Unsupervised physics-informed disentanglement of multimodal data for high-throughput scientific discovery

no code implementations7 Feb 2022 Nathaniel Trask, Carianne Martinez, Kookjin Lee, Brad Boyce

We introduce physics-informed multimodal autoencoders (PIMA) - a variational inference framework for discovering shared information in multimodal scientific datasets representative of high-throughput testing.

Decoder Disentanglement +2

Climate Modeling with Neural Diffusion Equations

2 code implementations11 Nov 2021 Jeehyun Hwang, Jeongwhan Choi, Hwangyong Choi, Kookjin Lee, Dongeun Lee, Noseong Park

On the other hand, neural ordinary differential equations (NODEs) are to learn a latent governing equation of ODE from data.

Weather Forecasting

Regularizing Image Classification Neural Networks with Partial Differential Equations

no code implementations29 Sep 2021 Jungeun Kim, Seunghyun Hwang, Jeehyun Hwang, Kookjin Lee, Dongeun Lee, Noseong Park

In other words, the knowledge contained by the learned governing equation can be injected into the neural network which approximates the PDE solution function.

Classification Image Classification

Structure-preserving Sparse Identification of Nonlinear Dynamics for Data-driven Modeling

no code implementations11 Sep 2021 Kookjin Lee, Nathaniel Trask, Panos Stinis

Discovery of dynamical systems from data forms the foundation for data-driven modeling and recently, structure-preserving geometric perspectives have been shown to provide improved forecasting, stability, and physical realizability guarantees.

Probabilistic partition of unity networks: clustering based deep approximation

no code implementations7 Jul 2021 Nat Trask, Mamikon Gulian, Andy Huang, Kookjin Lee

We enrich POU-Nets with a Gaussian noise model to obtain a probabilistic generalization amenable to gradient-based minimization of a maximum likelihood loss.

Clustering Probabilistic Deep Learning +2

Machine learning structure preserving brackets for forecasting irreversible processes

no code implementations NeurIPS 2021 Kookjin Lee, Nathaniel A. Trask, Panos Stinis

Forecasting of time-series data requires imposition of inductive biases to obtain predictive extrapolation, and recent works have imposed Hamiltonian/Lagrangian form to preserve structure for systems with reversible dynamics.

BIG-bench Machine Learning Form +2

Partition of unity networks: deep hp-approximation

no code implementations27 Jan 2021 Kookjin Lee, Nathaniel A. Trask, Ravi G. Patel, Mamikon A. Gulian, Eric C. Cyr

Approximation theorists have established best-in-class optimal approximation rates of deep neural networks by utilizing their ability to simultaneously emulate partitions of unity and monomials.

Unity

Neural Partial Differential Equations

no code implementations1 Jan 2021 Jungeun Kim, Seunghyun Hwang, Jihyun Hwang, Kookjin Lee, Dongeun Lee, Noseong Park

Neural ordinary differential equations (neural ODEs) introduced an approach to approximate a neural network as a system of ODEs after considering its layer as a continuous variable and discretizing its hidden dimension.

DPM: A Novel Training Method for Physics-Informed Neural Networks in Extrapolation

1 code implementation4 Dec 2020 Jungeun Kim, Kookjin Lee, Dongeun Lee, Sheo Yon Jin, Noseong Park

We present a method for learning dynamics of complex physical processes described by time-dependent nonlinear partial differential equations (PDEs).

Parameterized Neural Ordinary Differential Equations: Applications to Computational Physics Problems

no code implementations28 Oct 2020 Kookjin Lee, Eric J. Parish

This work proposes an extension of neural ordinary differential equations (NODEs) by introducing an additional set of ODE input parameters to NODEs.

Decoder

Deep Conservation: A latent dynamics model for exact satisfaction of physical conservation laws

no code implementations21 Sep 2019 Kookjin Lee, Kevin Carlberg

In contrast to existing methods for latent dynamics learning, this is the only method that both employs a nonlinear embedding and computes dynamics for the latent state that guarantee the satisfaction of prescribed physical properties.

Computational Physics

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