Ruby Sedgwick
ruby-sedgwick.bsky.social
Ruby Sedgwick
@ruby-sedgwick.bsky.social
Research Scientist at Xyme interested in Bayesian machine learning for biotechnology applications & causality. Previously a postdoc at Imperial College London.
(8/8) Check out the paper here: arxiv.org/abs/2402.09122
It was a pleasure working with James Odgers, Chrysoula Kappatou, Ruth Misener and Sarah Filippi on this project! If you are interested in knowing more, we’d love to hear from you.
Weighted-Sum of Gaussian Process Latent Variable Models
This work develops a Bayesian non-parametric approach to signal separation where the signals may vary according to latent variables. Our key contribution is to augment Gaussian Process Latent Variable...
arxiv.org
May 5, 2025 at 4:06 PM
(7/8) We demonstrate this approach on a synthetic test case, a spectroscopy dataset and oil flow data. Compared to baselines like inverse linear model of coregionalisation, classical least squares and partial least squares, WS-GPLVM achieves competitive or better performance.
May 5, 2025 at 4:06 PM
(6/8) This means not only do we get predictions of the component weights, but also a measure of uncertainty in these values. The Bayesian component weights and latent variables make the calculation of the evidence lower bound more challenging, and we show how this can be done.
May 5, 2025 at 4:06 PM
(5/8) At the core of this approach is the idea that each pure signal depends on a latent variable, and these signals combine linearly. We also treat the component weights in a Bayesian way, allowing for the inclusion of useful priors, such as summing-to-one.
May 5, 2025 at 4:06 PM
(4/8) This variability makes the separation task much harder. Most existing methods assume fixed pure signals. We introduce WS-GPLVM - a Bayesian nonparametric model that relaxes those assumptions.
May 5, 2025 at 4:06 PM
(3/8) Take spectroscopy for example: following Beer-Lambert’s law, the observed spectra is a linear combination of the spectra of the pure components, but these pure component spectra vary depending on experimental conditions.
May 5, 2025 at 4:06 PM
(2/8) In many real-world datasets, each observation is a mixture of underlying signals, with no observations of the pure signals. Think: chemical spectra, audio sources, hyperspectral images.
But what happens when the pure signals vary between samples due to some unobserved variables?
May 5, 2025 at 4:06 PM