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Related papers: Non regression testing for the JOREK code

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In recent years, the qualitative research on empirical software engineering that applies Grounded Theory is increasing. Grounded Theory (GT) is a technique for developing theory inductively e iteratively from qualitative data based on…

Software Engineering · Computer Science 2021-07-27 Jessica Díaz , Jorge Pérez , Carolina Gallardo , Ángel González-Prieto

Controlling and monitoring plasma within a tokamak device is complex and challenging. Plasma off-normal events, such as disruptions, are hindering steady-state operation. For large devices, they can even endanger the machine's integrity and…

Plasma Physics · Physics 2025-02-19 Andrin Bürli , Alessandro Pau , Thomas Koller , Olivier Sauter , JET Contributors

Non-stationarity of the rate or variance of events is a well-known problem in the description and analysis of time series of events, such as neuronal spike trains. A multiple filter test (MFT) for rate homogeneity has been proposed earlier…

Applications · Statistics 2018-10-03 Stefan Albert , Michael Messer , Julia Schiemann , Jochen Roeper , Gaby Schneider

We propose a nonparametric procedure to test for changes in correlation matrices at an unknown point in time. The new test requires only mild assumptions on the serial dependence structure and has considerable power in finite samples. We…

Methodology · Statistics 2014-10-29 Dominik Wied

Robust reinforcement learning (RRL) aims at seeking a robust policy to optimize the worst case performance over an uncertainty set of Markov decision processes (MDPs). This set contains some perturbed MDPs from a nominal MDP (N-MDP) that…

Machine Learning · Computer Science 2023-11-21 Ukjo Hwang , Songnam Hong

A detailed understanding of island seeding is crucial to avoid (N)TMs and their negative consequences like confinement degradation and disruptions. In the present work, we investigate the growth of 2/1 islands in response to magnetic…

Magnetohydrodynamics (MHD), combining fluid dynamics and Maxwell's equations, provides a useful means of analysing the dynamic evolution of plasmas and plasma instabilities. JOREK is a non-linear MHD code which solves these equations in the…

Plasma Physics · Physics 2024-02-07 Bridget McGibbon

We consider the task of robust non-linear regression in the presence of both inlier noise and outliers. Assuming that the unknown non-linear function belongs to a Reproducing Kernel Hilbert Space (RKHS), our goal is to estimate the set of…

Machine Learning · Computer Science 2017-08-02 George Papageorgiou , Pantelis Bouboulis , Sergios Theodoridis

We use the non-linear reduced-MHD code JOREK to study ELMs in the geometry of the ASDEX Upgrade tokamak. Toroidal mode numbers, poloidal filament sizes, and radial propagation speeds of filaments into the scrape-off layer are in good…

Personalized medicine seeks to identify the causal effect of treatment for a particular patient as opposed to a clinical population at large. Most investigators estimate such personalized treatment effects by regressing the outcome of a…

Machine Learning · Statistics 2021-09-02 Eric V. Strobl , Shyam Visweswaran

Existing statistical learning guarantees for general kernel regressors often yield loose bounds when used with finite-rank kernels. Yet, finite-rank kernels naturally appear in several machine learning problems, e.g.\ when fine-tuning a…

Machine Learning · Computer Science 2023-10-04 Tin Sum Cheng , Aurelien Lucchi , Ivan Dokmanić , Anastasis Kratsios , David Belius

Empirical modelling often aims for the simplest model consistent with the data. A new technique is presented which quantifies the consistency of the model dynamics as a function of location in state space. As is well-known, traditional…

Chaotic Dynamics · Physics 2009-11-10 Patrick E. McSharry , Leonard A. Smith

Despite significant progress of generative models in the natural sciences, their controllability remains challenging. One fundamentally missing aspect of molecular or protein generative models is an inductive bias that can reflect…

Machine Learning · Computer Science 2023-08-25 Jannis Born , Matteo Manica

Accurate modeling of core instabilities in tokamak plasmas is essential to understand the underlying physical mechanisms and their impact on plasma confinement. The ideal stability of the internal kink mode and the m = 1 collisionless…

There is an emerging trend in applying deep learning methods to control complex nonlinear systems. This paper considers enhancing the runtime safety of nonlinear systems controlled by neural networks in the presence of disturbance and…

Systems and Control · Electrical Eng. & Systems 2024-03-26 Jianglin Lan , Siyuan Zhan , Ron Patton , Xianxian Zhao

Early stopping of iterative algorithms is an algorithmic regularization method to avoid over-fitting in estimation and classification. In this paper, we show that early stopping can also be applied to obtain the minimax optimal testing in a…

Statistics Theory · Mathematics 2018-09-18 Meimei Liu , Guang Cheng

Increasing practical interest has been shown in regression problems where the errors, or disturbances, are centred in a way that reflects particular characteristics of the mechanism that generated the data. In economics this occurs in…

Statistics Theory · Mathematics 2009-09-07 Peter Hall , Ingrid Van Keilegom

Monotonicity is a key qualitative prediction of a wide array of economic models derived via robust comparative statics. It is therefore important to design effective and practical econometric methods for testing this prediction in empirical…

Statistics Theory · Mathematics 2019-07-10 Denis Chetverikov

Many scientific and engineering applications require fitting regression models that are nonlinear in the parameters. Advances in computer hardware and software in recent decades have made it easier to fit such models. Relative to fitting…

Methodology · Statistics 2024-03-20 Peng Liu , William Q. Meeker

This paper proposes parametric and non-parametric hypothesis testing algorithms for detecting anisotropy -- rotational variance of the covariance function in random fields. Both algorithms are based on resampling mechanisms, which enable…

Methodology · Statistics 2021-06-08 Assaf Rabinowicz , Saharon Rosset
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