Search Results for author: Alexandre M. Tartakovsky

Found 14 papers, 4 papers with code

Randomized Physics-Informed Machine Learning for Uncertainty Quantification in High-Dimensional Inverse Problems

no code implementations11 Dec 2023 Yifei Zong, David Barajas-Solano, Alexandre M. Tartakovsky

Uncertainty in the inverse solution is quantified in terms of the posterior distribution of CKLE coefficients, and we sample the posterior by solving a randomized PICKLE minimization problem, formulated by adding zero-mean Gaussian perturbations in the PICKLE loss function.

Physics-informed machine learning Uncertainty Quantification

Conditional Korhunen-Loéve regression model with Basis Adaptation for high-dimensional problems: uncertainty quantification and inverse modeling

no code implementations5 Jul 2023 Yu-Hong Yeung, Ramakrishna Tipireddy, David A. Barajas-Solano, Alexandre M. Tartakovsky

We propose a methodology for improving the accuracy of surrogate models of the observable response of physical systems as a function of the systems' spatially heterogeneous parameter fields with applications to uncertainty quantification and parameter estimation in high-dimensional problems.

Uncertainty Quantification

Gaussian process regression and conditional Karhunen-Loéve models for data assimilation in inverse problems

1 code implementation26 Jan 2023 Yu-Hong Yeung, David A. Barajas-Solano, Alexandre M. Tartakovsky

On the other hand, in CKLEMAP, the number of unknowns (CKLE coefficients) is controlled by the smoothness of the parameter field and the number of measurements, and is in general much smaller than the number of discretization nodes, which leads to a significant reduction of computational cost with respect to the standard MAP method.

regression

Physics-Informed Neural Network Method for Parabolic Differential Equations with Sharply Perturbed Initial Conditions

no code implementations18 Aug 2022 Yifei Zong, Qizhi He, Alexandre M. Tartakovsky

We propose a normalized form of ADE where the initial perturbation of the solution does not decrease in amplitude and demonstrate that this normalization significantly reduces the PINN approximation error.

Physics-Informed Machine Learning Method for Large-Scale Data Assimilation Problems

1 code implementation30 Jul 2021 Yu-Hong Yeung, David A. Barajas-Solano, Alexandre M. Tartakovsky

In our approach, we extend the physics-informed conditional Karhunen-Lo\'{e}ve expansion (PICKLE) method for modeling subsurface flow with unknown flux (Neumann) and varying head (Dirichlet) boundary conditions.

BIG-bench Machine Learning Physics-informed machine learning

Physics-informed CoKriging model of a redox flow battery

no code implementations17 Jun 2021 Amanda A. Howard, Alexandre M. Tartakovsky

Redox flow batteries (RFBs) offer the capability to store large amounts of energy cheaply and efficiently, however, there is a need for fast and accurate models of the charge-discharge curve of a RFB to potentially improve the battery capacity and performance.

Physics-Informed Gaussian Process Regression for Probabilistic States Estimation and Forecasting in Power Grids

no code implementations9 Oct 2020 Tong Ma, David Alonso Barajas-Solano, Ramakrishna Tipireddy, Alexandre M. Tartakovsky

For observed states, we show that PhI-GPR provides a forecast comparable to the standard data-driven GPR, with both forecasts being significantly more accurate than the autoregressive integrated moving average (ARIMA) forecast.

GPR regression

Learning Unknown Physics of non-Newtonian Fluids

no code implementations26 Aug 2020 Brandon Reyes, Amanda A. Howard, Paris Perdikaris, Alexandre M. Tartakovsky

Once a viscosity model is learned, we use the PINN method to solve the momentum conservation equation for non-Newtonian fluid flow using only the boundary conditions.

Physics-Informed Neural Networks for Multiphysics Data Assimilation with Application to Subsurface Transport

1 code implementation6 Dec 2019 QiZhi He, David Brajas-Solano, Guzel Tartakovsky, Alexandre M. Tartakovsky

We apply this approach to assimilate conductivity, hydraulic head, and concentration measurements for joint inversion of the conductivity, hydraulic head, and concentration fields in a steady-state advection--dispersion problem.

Learning Parameters and Constitutive Relationships with Physics Informed Deep Neural Networks

1 code implementation10 Aug 2018 Alexandre M. Tartakovsky, Carlos Ortiz Marrero, Paris Perdikaris, Guzel D. Tartakovsky, David Barajas-Solano

We employ physics informed DNNs to estimate the unknown space-dependent diffusion coefficient in a linear diffusion equation and an unknown constitutive relationship in a non-linear diffusion equation.

Analysis of PDEs Computational Physics

Enforcing constraints for interpolation and extrapolation in Generative Adversarial Networks

no code implementations22 Mar 2018 Panos Stinis, Tobias Hagge, Alexandre M. Tartakovsky, Enoch Yeung

We suggest ways to enforce given constraints in the output of a Generative Adversarial Network (GAN) generator both for interpolation and extrapolation (prediction).

Generative Adversarial Network Time Series Analysis

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