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We consider an unregularized optimal control problem subject to the steady-state Navier-Stokes equations. We derive the existence of optimal solutions and prove first- and second-order optimality conditions. To approximate solutions to the…

Numerical Analysis · Mathematics 2026-05-26 Francisco Fuica , Nicolai Jork

The paper focuses on the accuracy improvement of geometric and elasto-static calibration of industrial robots. It proposes industry-oriented performance measures for the calibration experiment design. They are based on the concept of…

Robotics · Computer Science 2012-11-27 Yier Wu , Alexandr Klimchik , Anatol Pashkevich , Stéphane Caro , Benoît Furet

In this work, weakly corrected explicit, semi-implicit and implicit Milstein approximations are presented for the solution of nonlinear stochastic differential equations. The solution trajectories provided by the Milstein schemes are…

Numerical Analysis · Mathematics 2021-08-25 Tapas Tripura , Budhaditya Hazra , Souvik Chakraborty

Machine learning was utilized to efficiently boost the development of soft magnetic materials. The design process includes building a database composed of published experimental results, applying machine learning methods on the database,…

A new paradigm for rapid stellarator configuration design has been recently demonstrated, in which the shapes of quasisymmetric or omnigenous flux surfaces are computed directly using an expansion in small distance from the magnetic axis.…

Plasma Physics · Physics 2021-03-08 Matt Landreman

We present an explicit theoretical framework for constructing artificial modular coils based solely on equilibrium properties, achieved through the formulation of a current potential defined on flux surfaces. We demonstrate that key…

Plasma Physics · Physics 2026-04-15 Eduardo Rodriguez , Wrick Sengupta

A method is given to rapidly compute quasisymmetric stellarator magnetic fields for plasma confinement, without the need to call a three-dimensional magnetohydrodynamic equilibrium code inside an optimization iteration. The method is based…

Plasma Physics · Physics 2019-12-04 Matt Landreman , Wrick Sengupta

This paper deals with the construction of a metamodel (i.e. a simplified mathematical model) for a stochastic computer code (also called stochastic numerical model or stochastic simulator), where stochastic means that the code maps the…

Statistics Theory · Mathematics 2015-09-15 Thomas Browne , Bertrand Iooss , Loïc Le Gratiet , Jérome Lonchampt

For cellular biochemical reaction systems where the numbers of molecules is small, significant noise is associated with chemical reaction events. This molecular noise can give rise to behavior that is very different from the predictions of…

Molecular Networks · Quantitative Biology 2009-11-13 Matthew Scott , Terence Hwa , Brian Ingalls

Stochastic optimisation algorithms are the de facto standard for machine learning with large amounts of data. Handling only a subset of available data in each optimisation step dramatically reduces the per-iteration computational costs,…

Numerical Analysis · Mathematics 2024-12-19 Matthias J. Ehrhardt , Zeljko Kereta , Jingwei Liang , Junqi Tang

A deformation of a neutron star due to its own magnetic field is an important issue in gravitational wave astronomy, since a misaligned rotator with small ellipticity may emit continuous gravitational wave that may be observed by…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Shin'ichirou Yoshida

The energetic optimization problem, e.g., searching for the optimal switch- ing protocol of certain system parameters to minimize the input work, has been extensively studied by stochastic thermodynamics. In current work, we study this…

Statistical Mechanics · Physics 2010-01-07 Linchen Gong , Ming Li , Zhong-can Ou-yang

The stochastic proximal gradient method is a powerful generalization of the widely used stochastic gradient descent (SGD) method and has found numerous applications in Machine Learning. However, it is notoriously known that this method…

Optimization and Control · Mathematics 2024-12-10 Yuan Gao , Anton Rodomanov , Sebastian U. Stich

Systems in nature are stochastic as well as nonlinear. In traditional applications, engineered filters aim to minimize the stochastic effects caused by process and measurement noise. Conversely, a previous study showed that the process…

Systems and Control · Electrical Eng. & Systems 2024-07-11 Burak Boyacıoğlu , Mahnoush Babaei , Amanuel H. Mamo , Sarah Bergbreiter , Thomas L. Daniel , Kristi A. Morgansen

Coil complexity is a critical consideration in stellarator design. The traditional two-step optimization approach, in which the plasma boundary is optimized for physics properties and the coils are subsequently optimized to be consistent…

Plasma Physics · Physics 2021-04-26 Arthur Carlton-Jones , Elizabeth J. Paul , William Dorland

In topology optimization of compliant mechanisms, the specific placement of boundary conditions strongly affects the resulting material distribution and performance of the design. At the same time, the most effective locations of the loads…

Computational Engineering, Finance, and Science · Computer Science 2025-02-05 Lee R. Alacoque , Anurag Bhattacharyya , Kai A. James

The distance between the last closed flux surface (LCFS) and the nearest electromagnetic coils is a dominating factor in the cost, size, and engineering difficulty of stellarators. The smallest magnetic gradient scale length on the LCFS -…

Plasma Physics · Physics 2026-02-24 John Kappel , Matt Landreman , Philipp Jurašić , Sophia A Henneberg

This paper delves into the realm of stochastic optimization for compositional minimax optimization - a pivotal challenge across various machine learning domains, including deep AUC and reinforcement learning policy evaluation. Despite its…

Machine Learning · Computer Science 2023-12-13 Jin Liu , Xiaokang Pan , Junwen Duan , Hongdong Li , Youqi Li , Zhe Qu

Stochastic computing (SC) is an emerging computing technique that promises high density, low power, and error tolerant solutions. In SC, values are encoded as unary bitstreams and SC arithmetic circuits operate on one or more bitstreams. In…

Signal Processing · Electrical Eng. & Systems 2018-03-14 Vincent T. Lee , Armin Alaghi , Luis Ceze

Kernel embeddings of distributions have recently gained significant attention in the machine learning community as a data-driven technique for representing probability distributions. Broadly, these techniques enable efficient computation of…

Optimization and Control · Mathematics 2021-03-25 Adam J. Thorpe , Meeko M. K. Oishi