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Ullrich Köthe

7 accepted papers

2024

Free-form Flows: Make Any Architecture a Normalizing Flow

AISTATS 2024poster

Normalizing Flows are generative models that directly maximize the likelihood. Previously, the design of normalizing flows was largely constrained by the need for analytical invertibility. We overcome this constraint by a training procedure that uses an efficient estimator for the gradient of the ch…

2023

Jana: Jointly amortized neural approximation of complex Bayesian models

UAI 2023poster

This work proposes “jointly amortized neural approximation” (JANA) of intractable likelihood functions and posterior densities arising in Bayesian surrogate modeling and simulation-based inference. We train three complementary networks in an end-to-end fashion: 1) a summary network to compress indiv…

Cited by 43SourcePDFScholar
2022

Towards Multimodal Depth Estimation From Light Fields

CVPR 2022poster

Light field applications, especially light field rendering and depth estimation, developed rapidly in recent years. While state-of-the-art light field rendering methods handle semi-transparent and reflective objects well, depth estimation methods either ignore these cases altogether or only deliver…

Cited by 14PDFScholar
2021

HINT: Hierarchical Invertible Neural Transport for Density Estimation and Bayesian Inference

AAAI 2021technical

Many recent invertible neural architectures are based on coupling block designs where variables are divided in two subsets which serve as inputs of an easily invertible (usually affine) triangular transformation. While such a transformation is invertible, its Jacobian is very sparse and thus may lac…

2020

Disentanglement by Nonlinear ICA with General Incompressible-flow Networks (GIN)

ICLR 2020spotlight

A central question of representation learning asks under which conditions it is possible to reconstruct the true latent variables of an arbitrarily complex generative process. Recent breakthrough work by Khemakhem et al. (2019) on nonlinear ICA has answered this question for a broad class of conditi…

Cited by 151SourceScholar
2020

Training Normalizing Flows with the Information Bottleneck for Competitive Generative Classification

NeurIPS 2020oral

The Information Bottleneck (IB) objective uses information theory to formulate a task-performance versus robustness trade-off. It has been successfully applied in the standard discriminative classification setting. We pose the question whether the IB can also be used to train generative likelihood m…

2019

Analyzing Inverse Problems with Invertible Neural Networks

ICLR 2019poster

For many applications, in particular in natural science, the task is to determine hidden system parameters from a set of measurements. Often, the forward process from parameter- to measurement-space is well-defined, whereas the inverse problem is ambiguous: multiple parameter sets can result in the…

Cited by 687SourcePDFScholar