Mathematical Sciences- Journal Articles
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Item Radiomic study of antenatal prediction of severe placenta accreta spectrum from MRI(Oxford University Press, 2024-08-17) Bartels, Helena C.; Wolsztynski, Eric; O'Doherty, Jim; Brophy, David P.; MacDermott, Roisin; Atallah, David; Saliba, Souha; El Kassis, Nadine; Moubarak, Malak; Young, Constance; Downey, Paul; Donnelly, Jennifer; Geoghegan, Tony; Brennan, Donal J.; Curran, Kathleen M.; National Maternity Hospital, Ireland; Science Foundation IrelandObjectives: We previously demonstrated the potential of radiomics for the prediction of severe histological placenta accreta spectrum (PAS) subtypes using T2-weighted MRI. We aim to validate our model using an additional dataset. Secondly, we explore whether the performance is improved using a new approach to develop a new multivariate radiomics model. Methods: Multi-centre retrospective analysis was conducted between 2018 and 2023. Inclusion criteria: MRI performed for suspicion of PAS from ultrasound, clinical findings of PAS at laparotomy and/or histopathological confirmation. Radiomic features were extracted from T2-weighted MRI. The previous multivariate model was validated. Secondly, a 5-radiomic feature random forest classifier was selected from a randomized feature selection scheme to predict invasive placenta increta PAS cases. Prediction performance was assessed based on several metrics including area under the curve (AUC) of the receiver operating characteristic curve (ROC), sensitivity, and specificity. Results: We present 100 women [mean age 34.6 (±3.9) with PAS], 64 of whom had placenta increta. Firstly, we validated the previous multivariate model and found that a support vector machine classifier had a sensitivity of 0.620 (95% CI: 0.068; 1.0), specificity of 0.619 (95% CI: 0.059; 1.0), an AUC of 0.671 (95% CI: 0.440; 0.922), and accuracy of 0.602 (95% CI: 0.353; 0.817) for predicting placenta increta. From the new multivariate model, the best 5-feature subset was selected via the random subset feature selection scheme comprised of 4 radiomic features and 1 clinical variable (number of previous caesareans). This clinical-radiomic model achieved an AUC of 0.713 (95% CI: 0.551; 0.854), accuracy of 0.695 (95% CI 0.563; 0.793), sensitivity of 0.843 (95% CI 0.682; 0.990), and specificity of 0.447 (95% CI 0.167; 0.667). Conclusion: We validated our previous model and present a new multivariate radiomic model for the prediction of severe placenta increta from a well-defined, cohort of PAS cases. Advances in knowledge: Radiomic features demonstrate good predictive potential for identifying placenta increta. This suggests radiomics may be a useful adjunct to clinicians caring for women with this high-risk pregnancy condition.Item The role of FPGAs in Modern Option Pricing techniques: A survey(MDPI, 2024-08-12) O'Mahony, Aidan; Hanzon, Bernard; Popovici, Emanuel; Science Foundation Ireland; Intel Corporation; Dell TechnologiesIn financial computation, Field Programmable Gate Arrays (FPGAs) have emerged as a transformative technology, particularly in the domain of option pricing. This study presents the impact of Field Programmable Gate Arrays (FPGAs) on computational methods in finance, with an emphasis on option pricing. Our review examined 99 selected studies from an initial pool of 131, revealing how FPGAs substantially enhance both the speed and energy efficiency of various financial models, particularly Black–Scholes and Monte Carlo simulations. Notably, the performance gains—ranging from 270- to 5400-times faster than conventional CPU implementations—are highly dependent on the specific option pricing model employed. These findings illustrate FPGAs’ capability to efficiently process complex financial computations while consuming less energy. Despite these benefits, this paper highlights persistent challenges in FPGA design optimization and programming complexity. This study not only emphasises the potential of FPGAs to further innovate financial computing but also outlines the critical areas for future research to overcome existing barriers and fully leverage FPGA technology in future financial applications.Item Conceptual climate modelling(Elsevier B.V., 2024-07-31) Krauskopf, Bernd; Keane, Andrew; Budd, ChrisModelling the climate is notoriously difficult and generally associated with high-dimensional general circulation models that may be quite unwieldy from the mathematical perspective. At the other end of the spectrum are seemingly simple conceptual models that focus on underlying mechanisms, such as the roles of different types of delayed feedback loops and/or switching phenomena for a specific climate phenomenon. This special issue is designed to highlight the usefulness of conceptual modelling in climate. It presents a number of conceptual climate models, discusses the mathematical techniques available for their analysis, and showcases how relevant insights can be gained from them, including informing more realistic modelling of the climate.Item Feynman–Kac perturbation of C* quantum stochastic flows(Springer Nature, 2024-07-06) Belton, Alexander C. R.; Wills, Stephen J.The method of Feynman–Kac perturbation of quantum stochastic processes has a long pedigree, with the theory usually developed within the framework of processes on von Neumann algebras. In this work, the theory of operator spaces is exploited to enable a broadening of the scope to flows on C* algebras. Although the hypotheses that need to be verified in this general setting may seem numerous, we provide auxiliary results that enable this to be simplified in many of the cases which arise in practice. A wide variety of examples is provided by way of illustration.Item Nonhydrostatic internal waves in the presence of mean currents and rotation(AIP Publishing, 2024-04-17) McCarney, Jordan; Science Foundation IrelandIn this paper we present a new exact solution that represents a Pollard-like, three-dimensional, nonlinear internal wave propagating on a non-uniform zonal current in a nonhydrostatic ocean model. The solution is presented in Lagrangian coordinates, and in the process we derive a dispersion relation for the internal wave which is subjected to a perturbative analysis which reveals the existence of two distinct modes of wave motion.