Search Results for author: Karthik Duraisamy

Found 16 papers, 7 papers with code

Variational Bayesian Optimal Experimental Design with Normalizing Flows

no code implementations8 Apr 2024 Jiayuan Dong, Christian Jacobsen, Mehdi Khalloufi, Maryam Akram, Wanjiao Liu, Karthik Duraisamy, Xun Huan

Variational OED (vOED), in contrast, estimates a lower bound of the EIG without likelihood evaluations by approximating the posterior distributions with variational forms, and then tightens the bound by optimizing its variational parameters.

Dimensionality Reduction Experimental Design

Enhancing Dynamical System Modeling through Interpretable Machine Learning Augmentations: A Case Study in Cathodic Electrophoretic Deposition

no code implementations16 Jan 2024 Christian Jacobsen, Jiayuan Dong, Mehdi Khalloufi, Xun Huan, Karthik Duraisamy, Maryam Akram, Wanjiao Liu

We introduce a comprehensive data-driven framework aimed at enhancing the modeling of physical systems, employing inference techniques and machine learning enhancements.

Interpretable Machine Learning

CoCoGen: Physically-Consistent and Conditioned Score-based Generative Models for Forward and Inverse Problems

no code implementations16 Dec 2023 Christian Jacobsen, Yilin Zhuang, Karthik Duraisamy

Secondly, we showcase the potential and versatility of score-based generative models in various physics tasks, specifically highlighting surrogate modeling as well as probabilistic field reconstruction and inversion from sparse measurements.

Drug Discovery

Easy attention: A simple self-attention mechanism for transformer-based time-series reconstruction and prediction

no code implementations24 Aug 2023 Marcial Sanchis-Agudo, Yuning Wang, Luca Guastoni, Karthik Duraisamy, Ricardo Vinuesa

To improve the robustness of transformer neural networks used for temporal-dynamics prediction of chaotic systems, we propose a novel attention mechanism called easy attention which we demonstrate in time-series reconstruction and prediction.

Temporal Sequences Time Series

On the lifting and reconstruction of nonlinear systems with multiple invariant sets

no code implementations24 Apr 2023 Shaowu Pan, Karthik Duraisamy

The Koopman operator provides a linear perspective on non-linear dynamics by focusing on the evolution of observables in an invariant subspace.

Misconceptions

Non-intrusive Balancing Transformation of Highly Stiff Systems with Lightly-damped Impulse Response

1 code implementation21 Sep 2021 Elnaz Rezaian, Cheng Huang, Karthik Duraisamy

Balanced truncation (BT) is a model reduction method that utilizes a coordinate transformation to retain eigen-directions that are highly observable and reachable.

Conditionally Parameterized, Discretization-Aware Neural Networks for Mesh-Based Modeling of Physical Systems

1 code implementation NeurIPS 2021 Jiayang Xu, Aniruddhe Pradhan, Karthik Duraisamy

Simulations of complex physical systems are typically realized by discretizing partial differential equations (PDEs) on unstructured meshes.

Super-Resolution

Disentangling Generative Factors of Physical Fields Using Variational Autoencoders

no code implementations15 Sep 2021 Christian Jacobsen, Karthik Duraisamy

We illustrate comparisons between disentangled and entangled representations by juxtaposing learned latent distributions and the true generative factors in a model porous flow problem.

Dimensionality Reduction Disentanglement

Discretization-independent surrogate modeling over complex geometries using hypernetworks and implicit representations

1 code implementation14 Sep 2021 James Duvall, Karthik Duraisamy, Shaowu Pan

Test cases include a vehicle-aerodynamics problem with complex geometry and limited training data, with a design-variable hypernetwork performing best, with a competitive time-to-best-model despite a much greater parameter count.

Variational Encoders and Autoencoders : Information-theoretic Inference and Closed-form Solutions

no code implementations27 Jan 2021 Karthik Duraisamy

This work develops problem statements related to encoders and autoencoders with the goal of elucidating variational formulations and establishing clear connections to information-theoretic concepts.

Variational Inference Information Theory Information Theory Probability 62B10 G.3; H.1.1

Sparsity-promoting algorithms for the discovery of informative Koopman invariant subspaces

1 code implementation25 Feb 2020 Shaowu Pan, Nicholas Arnold-Medabalimi, Karthik Duraisamy

Despite being endowed with a richer dictionary of nonlinear observables, nonlinear variants of the DMD, such as extended/kernel dynamic mode decomposition (EDMD/KDMD) are seldom applied to large-scale problems primarily due to the difficulty of discerning the Koopman invariant subspace from thousands of resulting Koopman eigenmodes.

Multi-level Convolutional Autoencoder Networks for Parametric Prediction of Spatio-temporal Dynamics

no code implementations23 Dec 2019 Jiayang Xu, Karthik Duraisamy

A fully-connected network is used as the third level to learn the mapping between these latent variables and the global parameters from training data, and predict them for new parameters.

Temporal Sequences

Physics-Informed Probabilistic Learning of Linear Embeddings of Non-linear Dynamics With Guaranteed Stability

1 code implementation9 Jun 2019 Shaowu Pan, Karthik Duraisamy

In this work, we formalize the problem of learning the continuous-time Koopman operator with deep neural networks in a measure-theoretic framework.

Variational Inference

Quad-rotor Flight Simulation in Realistic Atmospheric Conditions

1 code implementation4 Feb 2019 Behdad Davoudi, Ehsan Taheri, Karthik Duraisamy, Balaji Jayaraman, Ilya Kolmanovsky

A reduced-order version of the atmospheric boundary layer data as well as the popular Dryden model are used to assess the impact of accuracy of the wind field model on the predicted vehicle performance and trajectory.

Fluid Dynamics Atmospheric and Oceanic Physics Applied Physics

Long-time predictive modeling of nonlinear dynamical systems using neural networks

no code implementations31 May 2018 Shaowu Pan, Karthik Duraisamy

We study the use of feedforward neural networks (FNN) to develop models of nonlinear dynamical systems from data.

Data Augmentation

Data-driven Discovery of Closure Models

1 code implementation25 Mar 2018 Shaowu Pan, Karthik Duraisamy

In this work, we present a framework of operator inference to extract the governing dynamics of closure from data in a compact, non-Markovian form.

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