no code implementations • 11 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
no code implementations • 5 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.
1 code implementation • 26 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.
no code implementations • 18 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.
1 code implementation • 30 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
no code implementations • 17 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.
no code implementations • 9 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.
no code implementations • 8 Oct 2020 • Daniel Dylewsky, David Barajas-Solano, Tong Ma, Alexandre M. Tartakovsky, J. Nathan Kutz
Time series forecasting remains a central challenge problem in almost all scientific disciplines.
no code implementations • 26 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.
1 code implementation • 6 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.
no code implementations • 9 Oct 2019 • Tong Ma, Renke Huang, David Barajas-Solano, Ramakrishna Tipireddy, Alexandre M. Tartakovsky
We propose a new forecasting method for predicting load demand and generation scheduling.
1 code implementation • 10 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
no code implementations • 22 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).
no code implementations • 6 Oct 2017 • Tobias Hagge, Panos Stinis, Enoch Yeung, Alexandre M. Tartakovsky
We solve a system of ordinary differential equations with an unknown functional form of a sink (reaction rate) term.