Publications (19)
Uncertainty Quantification of Surrogate Models using Conformal Prediction
Vignesh Gopakumar, Ander Gray, Joel Oskarsson +5
Data-driven surrogate models offer quick approximations to complex numerical and experimental systems but typically lack uncertainty quantification, limiting their reliability in s…
Searching the SETI Ellipsoid with Gaia
James R. A. Davenport, Barbara Cabrales, Sofia Sheikh +4
The SETI Ellipsoid is a geometric method for prioritizing technosignature observations based on the strategy of receiving signals synchronized to conspicuous astronomical events. P…
Density Based Outlier Scoring on Kepler Data
Daniel Giles, Lucianne Walkowicz
In the present era of large scale surveys, big data presents new challenges to the discovery process for anomalous data. Such data can be indicative of systematic errors, extreme (…
Embedding machine-learnt sub-grid variability improves climate model biases
Daniel Giles, James Briant, Cyril J. Morcrette +1
The under-representation of cloud formation is a long-standing bias associated with climate simulations. Parameterisation schemes are required to capture cloud processes within cur…
Time-dependent influence metric for cascade dynamics on networks
James P. Gleeson, Ailbhe Cassidy, Daniel Giles +1
An algorithm for efficiently calculating the expected size of single-seed cascade dynamics on networks is proposed and tested. The expected size is a time-dependent quantity and so…
Systematic Serendipity: A Test of Unsupervised Machine Learning as a Method for Anomaly Detection
Daniel Giles, Lucianne Walkowicz
Advances in astronomy are often driven by serendipitous discoveries. As survey astronomy continues to grow, the size and complexity of astronomical databases will increase, and the…
Learning Chaos In A Linear Way
Xiaoyuan Cheng, Yi He, Yiming Yang +5
Learning long-term behaviors in chaotic dynamical systems, such as turbulent flows and climate modelling, is challenging due to their inherent instability and unpredictability. The…
Multilevel Bayesian Quadrature
Kaiyu Li, Daniel Giles, Toni Karvonen +2
Multilevel Monte Carlo is a key tool for approximating integrals involving expensive scientific models. The idea is to use approximations of the integrand to construct an estimator…
Tensor-Var: Efficient Four-Dimensional Variational Data Assimilation
Yiming Yang, Xiaoyuan Cheng, Daniel Giles +5
Variational data assimilation estimates the dynamical system states by minimizing a cost function that fits the numerical models with the observational data. Although four-dimensio…
Scalable Data Assimilation with Message Passing
Oscar Key, So Takao, Daniel Giles +1
Data assimilation is a core component of numerical weather prediction systems. The large quantity of data processed during assimilation requires the computation to be distributed a…
A Search for Transiting Exocomets in TESS Sectors 1-26
Azib Norazman, Grant M. Kennedy, Ann Marie Cody +3
We present a search for single photometric exocomet transits using a magnitude-limited sample of stars observed by the TESS primary mission. These events are asymmetric, with a sha…
Valid Error Bars for Neural Weather Models using Conformal Prediction
Vignesh Gopakumar, Joel Oskarrson, Ander Gray +5
Neural weather models have shown immense potential as inexpensive and accurate alternatives to physics-based models. However, most models trained to perform weather forecasting do…
The Log-Exponential Smoothing Technique and Nesterov's Accelerated Gradient Method for Generalized Sylvester Problems
Nguyen Thai An, Daniel Giles, Nguyen Mau Nam +1
The Sylvester smallest enclosing circle problem involves finding the smallest circle that encloses a finite number of points in the plane. We consider generalized versions of the S…
Modelling with Volna-OP2: Towards tsunami threat reduction
Daniel Giles, Brian McConnell, Frédéric Dias
Accurate and efficient tsunami modelling is essential for providing tsunami forecasts and hazard assessments. Volna-OP2 is a finite volume solver of the nonlinear shallow water equ…
Searching the SN 1987A SETI Ellipsoid with TESS
Bárbara Cabrales, James R. A. Davenport, Sofia Z. Sheikh +4
The SETI Ellipsoid is a strategy for technosignature candidate selection which assumes that extraterrestrial civilizations who have observed a galactic-scale event -- such as super…
Minimizing Differences of Convex Functions and Applications to Facility Location and Clustering
Nguyen Mau Nam, R. Blake Rector, Daniel Giles
In this paper we develop algorithms to solve generalized weighted Fermat-Torricelli problems with positive and negative weights and multifacility location problems involving distan…
Calibrated Physics-Informed Uncertainty Quantification
Vignesh Gopakumar, Ander Gray, Lorenzo Zanisi +5
Simulating complex physical systems is crucial for understanding and predicting phenomena across diverse fields, such as fluid dynamics and heat transfer, as well as plasma physics…
A method for finding anomalous astronomical light curves and their analogs
Juan Rafael MartÃnez-Galarza, Federica Bianco, Dennis Crake +4
Our understanding of the Universe has profited from deliberate, targeted studies of known phenomena, as well as from serendipitous, unexpected discoveries, such as the discovery of…
Performance analysis of Volna-OP2 -- massively parallel code for tsunami modelling
Daniel Giles, Eugene Kashdan, Dimitra M. Salmanidou +2
The software package Volna-OP2 is a robust and efficient code capable of simulating the complete life cycle of a tsunami whilst harnessing the latest High Performance Computing (HP…