Search Results for author: Youssef Marzouk

Found 29 papers, 12 papers with code

Preserving linear invariants in ensemble filtering methods

1 code implementation22 Apr 2024 Mathieu Le Provost, Jan Glaubitz, Youssef Marzouk

Finally, we assess the benefits of preserving linear invariants for the ensemble Kalman filter and nonlinear ensemble filters.

Nonlinear Bayesian optimal experimental design using logarithmic Sobolev inequalities

no code implementations23 Feb 2024 Fengyi Li, Ayoub Belhadji, Youssef Marzouk

We study the problem of selecting $k$ experiments from a larger candidate pool, where the goal is to maximize mutual information (MI) between the selected subset and the underlying parameters.

Combinatorial Optimization Experimental Design

Multitask methods for predicting molecular properties from heterogeneous data

no code implementations31 Jan 2024 Katharine Fisher, Michael Herbst, Youssef Marzouk

Data generation remains a bottleneck in training surrogate models to predict molecular properties.

regression

Stable generative modeling using diffusion maps

no code implementations9 Jan 2024 Georg Gottwald, Fengyi Li, Youssef Marzouk, Sebastian Reich

Diffusion maps are used to approximate the drift term from the available training samples, which is then implemented in a discrete-time Langevin sampler to generate new samples.

Sampling in Unit Time with Kernel Fisher-Rao Flow

1 code implementation8 Jan 2024 Aimee Maurais, Youssef Marzouk

We introduce a new mean-field ODE and corresponding interacting particle systems (IPS) for sampling from an unnormalized target density.

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.

Distribution learning via neural differential equations: a nonparametric statistical perspective

no code implementations3 Sep 2023 Youssef Marzouk, Zhi Ren, Sven Wang, Jakob Zech

Ordinary differential equations (ODEs), via their induced flow maps, provide a powerful framework to parameterize invertible transformations for the purpose of representing complex probability distributions.

Density Estimation

A transport approach to sequential simulation-based inference

no code implementations26 Aug 2023 Paul-Baptiste Rubio, Youssef Marzouk, Matthew Parno

We present a new transport-based approach to efficiently perform sequential Bayesian inference of static model parameters.

Bayesian Inference Sequential Bayesian Inference

Multifidelity Covariance Estimation via Regression on the Manifold of Symmetric Positive Definite Matrices

no code implementations23 Jul 2023 Aimee Maurais, Terrence Alsup, Benjamin Peherstorfer, Youssef Marzouk

We introduce a multifidelity estimator of covariance matrices formulated as the solution to a regression problem on the manifold of symmetric positive definite matrices.

Metric Learning regression

Score Operator Newton transport

no code implementations16 May 2023 Nisha Chandramoorthy, Florian Schaefer, Youssef Marzouk

We propose a new approach for sampling and Bayesian computation that uses the score of the target distribution to construct a transport from a given reference distribution to the target.

Bayesian Inference valid +1

Diffusion map particle systems for generative modeling

no code implementations1 Apr 2023 Fengyi Li, Youssef Marzouk

We propose a novel diffusion map particle system (DMPS) for generative modeling, based on diffusion maps and Laplacian-adjusted Wasserstein gradient descent (LAWGD).

Infinite-Dimensional Diffusion Models

no code implementations20 Feb 2023 Jakiw Pidstrigach, Youssef Marzouk, Sebastian Reich, Sven Wang

For image distributions, these guidelines are in line with the canonical choices currently made for diffusion models.

Time Series

Multi-Fidelity Covariance Estimation in the Log-Euclidean Geometry

1 code implementation31 Jan 2023 Aimee Maurais, Terrence Alsup, Benjamin Peherstorfer, Youssef Marzouk

We introduce a multi-fidelity estimator of covariance matrices that employs the log-Euclidean geometry of the symmetric positive-definite manifold.

Metric Learning

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

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

On minimax density estimation via measure transport

no code implementations20 Jul 2022 Sven Wang, Youssef Marzouk

We study the convergence properties, in Hellinger and related distances, of nonparametric density estimators based on measure transport.

Density Estimation

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.

Sampling via Controlled Stochastic Dynamical Systems

no code implementations NeurIPS Workshop ICBINB 2021 Benjamin Zhang, Tuhin Sahai, Youssef Marzouk

Given a target distribution and a reference stochastic differential equation (SDE), the Doob $h$-transform produces a controlled stochastic process whose marginal at a finite time $T$ will be equal to the target distribution.

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.

Geodesically parameterized covariance estimation

no code implementations6 Jan 2020 Antoni Musolas, Steven T. Smith, Youssef Marzouk

We consider instead a differential geometric interpretation of this problem: minimizing the geodesic distance to a sample covariance matrix ("natural projection").

Computation Differential Geometry

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.

Greedy inference with structure-exploiting lazy maps

1 code implementation NeurIPS 2020 Michael C. Brennan, Daniele Bigoni, Olivier Zahm, Alessio Spantini, Youssef Marzouk

We prove weak convergence of the generated sequence of distributions to the posterior, and we demonstrate the benefits of the framework on challenging inference problems in machine learning and differential equations, using inverse autoregressive flows and polynomial maps as examples of the underlying density estimators.

Bayesian Inference

A Stein variational Newton method

1 code implementation NeurIPS 2018 Gianluca Detommaso, Tiangang Cui, Alessio Spantini, Youssef Marzouk, Robert Scheichl

Stein variational gradient descent (SVGD) was recently proposed as a general purpose nonparametric variational inference algorithm [Liu & Wang, NIPS 2016]: it minimizes the Kullback-Leibler divergence between the target distribution and its approximation by implementing a form of functional gradient descent on a reproducing kernel Hilbert space.

Variational Inference

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.

Inference via low-dimensional couplings

no code implementations17 Mar 2017 Alessio Spantini, Daniele Bigoni, Youssef Marzouk

In the context of statistics and machine learning, these transformations can be used to couple a tractable "reference" measure (e. g., a standard Gaussian) with a target measure of interest.

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