Ryan‐Rhys Griffiths

ORCID: 0000-0003-3117-4559
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Research Areas
  • Machine Learning in Materials Science
  • Computational Drug Discovery Methods
  • Advanced Multi-Objective Optimization Algorithms
  • Machine Learning and Algorithms
  • Machine Learning and Data Classification
  • Human Pose and Action Recognition
  • Aesthetic Perception and Analysis
  • Gaussian Processes and Bayesian Inference
  • Gait Recognition and Analysis
  • Advanced Bandit Algorithms Research
  • Radical Photochemical Reactions
  • Advanced Photocatalysis Techniques
  • Chemistry and Chemical Engineering
  • Photochromic and Fluorescence Chemistry
  • Human Motion and Animation
  • Conservation Techniques and Studies
  • Gamma-ray bursts and supernovae
  • Computer Graphics and Visualization Techniques
  • Music and Audio Processing
  • Mass Spectrometry Techniques and Applications
  • Multimodal Machine Learning Applications
  • Cultural Heritage Materials Analysis
  • Anomaly Detection Techniques and Applications
  • Image and Signal Denoising Methods
  • Generative Adversarial Networks and Image Synthesis

University of Cambridge
2017-2024

Oxfam
2023

Technical University of Darmstadt
2022

Huawei Technologies (United Kingdom)
2022

University College London
2022

Huawei Technologies (China)
2020

Imperial College London
2020

Automatic Chemical Design is a framework for generating novel molecules with optimized properties.

10.1039/c9sc04026a article EN cc-by Chemical Science 2019-11-18

We investigate the mathematical capabilities of two iterations ChatGPT (released 9-January-2023 and 30-January-2023) GPT-4 by testing them on publicly available datasets, as well hand-crafted ones, using a novel methodology. In contrast to formal mathematics, where large databases proofs are (e.g., Lean Mathematical Library), current datasets natural-language used benchmark language models, either cover only elementary mathematics or very small. address this releasing new datasets: GHOSTS...

10.48550/arxiv.2301.13867 preprint EN other-oa arXiv (Cornell University) 2023-01-01

ConspectusThe visualization of data is indispensable in scientific research, from the early stages when human insight forms to final step communicating results. In computational physics, chemistry and materials science, it can be as simple making a scatter plot or straightforward looking through snapshots atomic positions manually. However, result "big data" revolution, these conventional approaches are often inadequate. The widespread adoption high-throughput computation for discovery...

10.1021/acs.accounts.0c00403 article EN Accounts of Chemical Research 2020-08-14

In this work we rigorously analyse assumptions inherent to black-box optimisation hyper-parameter tuning tasks. Our results on the Bayesmark benchmark indicate that heteroscedasticity and non-stationarity pose significant challenges for optimisers. Based these findings, propose a Heteroscedastic Evolutionary Bayesian Optimisation solver (HEBO). HEBO performs non-linear input output warping, admits exact marginal log-likelihood is robust values of learned parameters. We demonstrate HEBO’s...

10.1613/jair.1.13643 article EN cc-by Journal of Artificial Intelligence Research 2022-07-11

Automatic Chemical Design is a framework for generating novel molecules with optimized properties. The original scheme, featuring Bayesian optimization over the latent space of variational autoencoder, suffers from pathology that it tends to produce invalid molecular structures. First, we demonstrate empirically this arises when scheme queries points far away data on which autoencoder has been trained. Secondly, by reformulating search procedure as constrained problem, show effects can be...

10.48550/arxiv.1709.05501 preprint EN other-oa arXiv (Cornell University) 2017-01-01

We present a data-driven discovery pipeline for molecular photoswitches through multitask learning with Gaussian processes. Through subsequent screening, we identify several motifs separated and red-shifted electronic absorption bands.

10.1039/d2sc04306h article EN cc-by Chemical Science 2022-01-01

We introduce a method combining variational autoencoders (VAEs) and deep metric learning to perform Bayesian optimisation (BO) over high-dimensional structured input spaces. By adapting ideas from learning, we use label guidance the blackbox function structure VAE latent space, facilitating Gaussian process fit yielding improved BO performance. Importantly for problem settings, our operates in semi-supervised regimes where only few labelled data points are available. run experiments on three...

10.48550/arxiv.2106.03609 preprint EN other-oa arXiv (Cornell University) 2021-01-01

We introduce GAUCHE, a library for GAUssian processes in CHEmistry. Gaussian have long been cornerstone of probabilistic machine learning, affording particular advantages uncertainty quantification and Bayesian optimisation. Extending to chemical representations, however, is nontrivial, necessitating kernels defined over structured inputs such as graphs, strings bit vectors. By defining we seek open the door powerful tools optimisation chemistry. Motivated by scenarios frequently encountered...

10.48550/arxiv.2212.04450 preprint EN cc-by arXiv (Cornell University) 2022-01-01

The task of predicting human motion is complicated by the natural heterogeneity and compositionality actions, necessitating robustness to distributional shifts as far out-of-distribution (OoD). Here, we formulate a new OoD benchmark based on Human3.6M Carnegie Mellon University (CMU) capture datasets, introduce hybrid framework for hardening discriminative architectures failure augmenting them with generative model. When applied current state-of-the-art models, show that proposed approach...

10.1002/ail2.63 article EN Applied AI Letters 2022-01-17

Bayesian optimisation is a sample-efficient search methodology that holds great promise for accelerating drug and materials discovery programs. A frequently-overlooked modelling consideration in strategies however, the representation of heteroscedastic aleatoric uncertainty. In many practical applications it desirable to identify inputs with low noise, an example which might be material composition consistently displays robust properties response noisy fabrication process. this paper, we...

10.1088/2632-2153/ac298c article EN cc-by Machine Learning Science and Technology 2021-09-23

Precise celestial positions have been obtained with the HEAO 1 scanning modulation collimators for highly variable X-ray source GX 339--4 (4U 1658--48) and burst MXB 1659--29. Both sources are identified faint (17-18 mag) blue objects He II lambda4686 lambdalambda4640--50 emission.

10.1086/182905 article EN The Astrophysical Journal 1979-03-01

We present FlowMO: an open-source Python library for molecular property prediction with Gaussian Processes. Built upon GPflow and RDKit, FlowMO enables the user to make predictions well-calibrated uncertainty estimates, output central active learning design applications. Processes are particularly attractive modelling small datasets, a characteristic of many real-world virtual screening campaigns where high-quality experimental data is scarce. Computational experiments across three datasets...

10.48550/arxiv.2010.01118 preprint EN other-oa arXiv (Cornell University) 2020-01-01

Abstract The optical and UV variability of the majority active galactic nuclei may be related to reprocessing rapidly changing X-ray emission from a more compact region near central black hole. Such model would characterized by lags between optical/UV due differences in light travel time. Observationally, however, such lag features have been difficult detect gaps lightcurves introduced through factors as source visibility or limited telescope In this work, Gaussian process regression is...

10.3847/1538-4357/abfa9f article EN The Astrophysical Journal 2021-06-01

Cost-effective Bayesian optimisation screening of 720 additives on four complex reactions, achieving substantial yield improvements over baselines using chemical reaction representations beyond one-hot encoding.

10.1039/d3dd00096f article EN cc-by Digital Discovery 2023-11-02

In this work we rigorously analyse assumptions inherent to black-box optimisation hyper-parameter tuning tasks. Our results on the Bayesmark benchmark indicate that heteroscedasticity and non-stationarity pose significant challenges for optimisers. Based these findings, propose a Heteroscedastic Evolutionary Bayesian Optimisation solver (HEBO). HEBO performs non-linear input output warping, admits exact marginal log-likelihood is robust values of learned parameters. We demonstrate HEBO's...

10.48550/arxiv.2012.03826 preprint EN cc-by arXiv (Cornell University) 2020-01-01

The space of synthesizable molecules is greater than $10^{60}$, meaning only a vanishingly small fraction these have ever been realized in the lab. In order to prioritize which regions this explore next, synthetic chemists need access accurate molecular property predictions. While great advances machine learning made, there dearth benchmarks featuring properties that are useful for chemist. Focussing directly on needs chemist, we introduce Photoswitch Dataset, new benchmark where...

10.26434/chemrxiv.12609899 preprint EN cc-by-nc-nd 2020-07-06

We deploy a prompt-augmented GPT-4 model to distill comprehensive datasets on the global application of debt-for-nature swaps (DNS), pivotal financial tool for environmental conservation. Our analysis includes 195 nations and identifies 21 countries that have not yet used DNS before as prime candidates DNS. A significant proportion demonstrates consistent commitments conservation finance (0.86 accuracy compared historical records). Conversely, 35 previously active in 2010 since been...

10.3389/frai.2024.1167137 article EN cc-by Frontiers in Artificial Intelligence 2024-02-05

Bayesian optimisation presents a sample-efficient methodology for global optimisation. Within this framework, crucial performance-determining subroutine is the maximisation of acquisition function, task complicated by fact that functions tend to be non-convex and thus nontrivial optimise. In paper, we undertake comprehensive empirical study approaches maximise function. Additionally, deriving novel, yet mathematically equivalent, compositional forms popular functions, recast as problem,...

10.48550/arxiv.2012.08240 preprint EN other-oa arXiv (Cornell University) 2020-01-01

Datasets in the Natural Sciences are often curated with goal of aiding scientific understanding and hence may not always be a form that facilitates application machine learning. In this paper, we identify three trends within fields chemical reaction prediction synthesis design require change direction. First, manner which datasets split into reactants reagents encourages testing models an unrealistically generous manner. Second, highlight prevalence mislabelled data, suggest focus should on...

10.26434/chemrxiv.7366973.v1 preprint EN 2018-11-21

Reaction additives play a significant role in controlling the reactivity and outcomes of chemical reactions. For example, recent high-throughput additive screening identified phthalimide ligand for Ni-catalysed photoredox decarboxylative arylations. This discovery enabled 4-fold yield improvement by stabilising oxidative addition complexes breaking up deactivated catalyst aggregates. Despite promise such large-scale screenings, they remain inaccessible to most research groups due their cost...

10.26434/chemrxiv-2022-nll2j-v3 preprint EN cc-by-nc 2023-06-15

The space of synthesizable molecules is greater than $10^{60}$, meaning only a vanishingly small fraction these have ever been realized in the lab. In order to prioritize which regions this explore next, synthetic chemists need access accurate molecular property predictions. While great advances machine learning made, there dearth benchmarks featuring properties that are useful for chemist. Focussing directly on needs chemist, we introduce Photoswitch Dataset, new benchmark where...

10.26434/chemrxiv.12609899.v1 preprint EN 2020-07-06

In many areas of the observational and experimental sciences data is scarce. Data observation in high-energy astrophysics disrupted by celestial occlusions limited telescope time while derived from laboratory experiments synthetic chemistry materials science cost-intensive to collect. On other hand, knowledge about data-generation mechanism often available sciences, such as measurement error a piece apparatus. Both characteristics, small underlying physics, make Gaussian processes (GPs)...

10.48550/arxiv.2303.14291 preprint EN cc-by arXiv (Cornell University) 2023-01-01

We consider the problem of adaptively placing sensors along an interval to detect stochastically-generated events. present a new formulation as continuum-armed bandit with feedback in form partial observations realisations inhomogeneous Poisson process. design solution method by combining Thompson sampling nonparametric inference via increasingly granular Bayesian histograms and derive $\tilde{O}(T^{2/3})$ bound on regret $T$ rounds. This is coupled efficent optimisation approach select...

10.48550/arxiv.1905.06821 preprint EN other-oa arXiv (Cornell University) 2019-01-01
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