Search Results for author: Ricardo Baptista

Found 16 papers, 10 papers with code

Efficient Neural Network Approaches for Conditional Optimal Transport with Applications in Bayesian Inference

2 code implementations25 Oct 2023 Zheyu Oliver Wang, Ricardo Baptista, Youssef Marzouk, Lars Ruthotto, Deepanshu Verma

PCP-Map models conditional transport maps as the gradient of a partially input convex neural network (PICNN) and uses a novel numerical implementation to increase computational efficiency compared to state-of-the-art alternatives.

Bayesian Inference Computational Efficiency +2

An adaptive ensemble filter for heavy-tailed distributions: tuning-free inflation and localization

1 code implementation12 Oct 2023 Mathieu Le Provost, Ricardo Baptista, Jeff D. Eldredge, Youssef Marzouk

In these settings, the Kalman filter and its ensemble version - the ensemble Kalman filter (EnKF) - that have been designed under Gaussian assumptions result in degraded performance.

Score-based Diffusion Models in Function Space

no code implementations14 Feb 2023 Jae Hyun Lim, Nikola B. Kovachki, Ricardo Baptista, Christopher Beckham, Kamyar Azizzadenesheli, Jean Kossaifi, Vikram Voleti, Jiaming Song, Karsten Kreis, Jan Kautz, Christopher Pal, Arash Vahdat, Anima Anandkumar

They consist of a forward process that perturbs input data with Gaussian white noise and a reverse process that learns a score function to generate samples by denoising.

Denoising

Ensemble transport smoothing. Part II: Nonlinear updates

1 code implementation31 Oct 2022 Maximilian Ramgraber, Ricardo Baptista, Dennis McLaughlin, Youssef Marzouk

Smoothing is a specialized form of Bayesian inference for state-space models that characterizes the posterior distribution of a collection of states given an associated sequence of observations.

Bayesian Inference

Ensemble transport smoothing. Part I: Unified framework

1 code implementation31 Oct 2022 Maximilian Ramgraber, Ricardo Baptista, Dennis McLaughlin, Youssef Marzouk

A companion paper (Ramgraber et al., 2023) explores the implementation of nonlinear ensemble transport smoothers in greater depth.

Bayesian Inference Computational Efficiency +2

Bayesian model calibration for block copolymer self-assembly: Likelihood-free inference and expected information gain computation via measure transport

no code implementations22 Jun 2022 Ricardo Baptista, Lianghao Cao, Joshua Chen, Omar Ghattas, Fengyi Li, Youssef M. Marzouk, J. Tinsley Oden

We tackle this challenging Bayesian inference problem using a likelihood-free approach based on measure transport together with the construction of summary statistics for the image data.

Bayesian Inference Informativeness

A low-rank ensemble Kalman filter for elliptic observations

2 code implementations10 Mar 2022 Mathieu Le Provost, Ricardo Baptista, Youssef Marzouk, Jeff D. Eldredge

We propose a regularization method for ensemble Kalman filtering (EnKF) with elliptic observation operators.

Diagonal Nonlinear Transformations Preserve Structure in Covariance and Precision Matrices

no code implementations8 Jul 2021 Rebecca E Morrison, Ricardo Baptista, Estelle L Basor

For a multivariate normal distribution, the sparsity of the covariance and precision matrices encodes complete information about independence and conditional independence properties.

Learning non-Gaussian graphical models via Hessian scores and triangular transport

no code implementations8 Jan 2021 Ricardo Baptista, Youssef Marzouk, Rebecca E. Morrison, Olivier Zahm

Undirected probabilistic graphical models represent the conditional dependencies, or Markov properties, of a collection of random variables.

On the representation and learning of monotone triangular transport maps

1 code implementation22 Sep 2020 Ricardo Baptista, Youssef Marzouk, Olivier Zahm

Transportation of measure provides a versatile approach for modeling complex probability distributions, with applications in density estimation, Bayesian inference, generative modeling, and beyond.

Bayesian Inference Density Estimation

Conditional Sampling with Monotone GANs: from Generative Models to Likelihood-Free Inference

1 code implementation11 Jun 2020 Ricardo Baptista, Bamdad Hosseini, Nikola B. Kovachki, Youssef Marzouk

We present a novel framework for conditional sampling of probability measures, using block triangular transport maps.

Coupling techniques for nonlinear ensemble filtering

no code implementations30 Jun 2019 Alessio Spantini, Ricardo Baptista, Youssef Marzouk

We consider filtering in high-dimensional non-Gaussian state-space models with intractable transition kernels, nonlinear and possibly chaotic dynamics, and sparse observations in space and time.

Bayesian Optimization of Combinatorial Structures

2 code implementations ICML 2018 Ricardo Baptista, Matthias Poloczek

The optimization of expensive-to-evaluate black-box functions over combinatorial structures is an ubiquitous task in machine learning, engineering and the natural sciences.

Bayesian Optimization BIG-bench Machine Learning

Beyond normality: Learning sparse probabilistic graphical models in the non-Gaussian setting

no code implementations NeurIPS 2017 Rebecca E. Morrison, Ricardo Baptista, Youssef Marzouk

We present an algorithm to identify sparse dependence structure in continuous and non-Gaussian probability distributions, given a corresponding set of data.

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