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Harri Lähdesmäki

17 accepted papers

2026

Modeling temporal scRNA-seq data with latent Gaussian process and optimal transport

ICML 2026poster

Single-cell RNA sequencing provides insights into gene expression at single-cell resolution, yet inferring temporal processes from these static snapshot measurements remains a fundamental challenge. Current approaches utilizing neural differential equations and flows are sensitive to overfitting and…

Cited by 0SourceScholar
2025

Bayesian Basis Function Approximation for Scalable Gaussian Process Priors in Deep Generative Models

ICML 2025poster

High-dimensional time-series datasets are common in domains such as healthcare and economics. Variational autoencoder (VAE) models, where latent variables are modeled with a Gaussian process (GP) prior, have become a prominent model class to analyze such correlated datasets. However, their applicati…

Cited by 0SourcePDFScholar
2025

E(3)-equivariant models cannot learn chirality: Field-based molecular generation

ICLR 2025poster

Obtaining the desired effect of drugs is highly dependent on their molecular geometries. Thus, the current prevailing paradigm focuses on 3D point-cloud atom representations, utilizing graph neural network (GNN) parametrizations, with rotational symmetries baked in via E(3) invariant layers. We prov…

Cited by 0SourcePDFScholar
2025

High-Dimensional Bayesian Optimisation with Gaussian Process Prior Variational Autoencoders

ICLR 2025poster

Bayesian optimisation (BO) using a Gaussian process (GP)-based surrogate model is a powerful tool for solving black-box optimisation problems but does not scale well to high-dimensional data. Previous works have proposed to use variational autoencoders (VAEs) to project high-dimensional data onto a…

Cited by 0SourcePDFScholar
2025

Learning Spatiotemporal Dynamical Systems from Point Process Observations

ICLR 2025spotlight

Spatiotemporal dynamics models are fundamental for various domains, from heat propagation in materials to oceanic and atmospheric flows. However, currently available neural network-based spatiotemporal modeling approaches fall short when faced with data that is collected randomly over time and space…

Cited by 0SourcePDFScholar
2024

Estimating treatment effects from single-arm trials via latent-variable modeling

AISTATS 2024poster

Randomized controlled trials (RCTs) are the accepted standard for treatment effect estimation but they can be infeasible due to ethical reasons and prohibitive costs. Single-arm trials, where all patients belong to the treatment group, can be a viable alternative but require access to an external co…

2024

Latent variable model for high-dimensional point process with structured missingness

ICML 2024poster

Longitudinal data are important in numerous fields, such as healthcare, sociology and seismology, but real-world datasets present notable challenges for practitioners because they can be high-dimensional, contain structured missingness patterns, and measurement time points can be governed by an unkn…

2023

Latent Neural ODEs with Sparse Bayesian Multiple Shooting

ICLR 2023poster

Training dynamic models, such as neural ODEs, on long trajectories is a hard problem that requires using various tricks, such as trajectory splitting, to make model training work in practice. These methods are often heuristics with poor theoretical justifications, and require iterative manual tuning…

2023

Learning Space-Time Continuous Latent Neural PDEs from Partially Observed States

NeurIPS 2023poster

We introduce a novel grid-independent model for learning partial differential equations (PDEs) from noisy and partial observations on irregular spatiotemporal grids. We propose a space-time continuous latent neural PDE model with an efficient probabilistic framework and a novel encoder design for im…

Cited by 3SourcePDFScholar
2022

Variational multiple shooting for Bayesian ODEs with Gaussian processes

UAI 2022poster

Recent machine learning advances have proposed black-box estimation of \textit{unknown continuous-time system dynamics} directly from data. However, earlier works are based on approximative solutions or point estimates. We propose a novel Bayesian nonparametric model that uses Gaussian processes to…

2021

Continuous-time Model-based Reinforcement Learning

ICML 2021spotlight

Model-based reinforcement learning (MBRL) approaches rely on discrete-time state transition models whereas physical systems and the vast majority of control tasks operate in continuous-time. To avoid time-discretization approximation of the underlying process, we propose a continuous-time MBRL frame…

2021

Latent Gaussian process with composite likelihoods and numerical quadrature

AISTATS 2021poster

Clinical patient records are an example of high-dimensional data that is typically collected from disparate sources and comprises of multiple likelihoods with noisy as well as missing values. In this work, we propose an unsupervised generative model that can learn a low-dimensional representation am…

Cited by 11SourcePDFScholar
2021

Learning continuous-time PDEs from sparse data with graph neural networks

ICLR 2021poster

The behavior of many dynamical systems follow complex, yet still unknown partial differential equations (PDEs). While several machine learning methods have been proposed to learn PDEs directly from data, previous methods are limited to discrete-time approximations or make the limiting assumption of…

Cited by 85SourcePDFScholar
2021

Longitudinal Variational Autoencoder

AISTATS 2021poster

Longitudinal datasets measured repeatedly over time from individual subjects, arise in many biomedical, psychological, social, and other studies. A common approach to analyse high-dimensional data that contains missing values is to learn a low-dimensional representation using variational autoencoder…

Cited by 57SourcePDFScholar
2019

Deep learning with differential Gaussian process flows

AISTATS 2019poster

We propose a novel deep learning paradigm of differential flows that learn a stochastic differential equation transformations of inputs prior to a standard classification or regression function. The key property of differential Gaussian processes is the warping of inputs through infinitely deep, but…

Cited by 55SourcePDFScholar
2018

Learning unknown ODE models with Gaussian processes

ICML 2018oral

In conventional ODE modelling coefficients of an equation driving the system state forward in time are estimated. However, for many complex systems it is practically impossible to determine the equations or interactions governing the underlying dynamics. In these settings, parametric ODE model canno…

2016

Non-Stationary Gaussian Process Regression with Hamiltonian Monte Carlo

AISTATS 2016poster

We present a novel approach for non-stationary Gaussian process regression (GPR), where the three key parameters – noise variance, signal variance and lengthscale – can be simultaneously input-dependent. We develop gradient-based inference methods to learn the unknown function and the non-stationary…