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In this article, three optimization approaches are exploited to improve the performance of a permanent magnet-assisted synchronous reluctance machine: a first optimization using fixed substitution models and two Bayesian optimization…

Optimization and Control · Mathematics 2023-10-03 Adan Reyes Reyes , André Nasr , Delphine Sinoquet , Sami Hlioui

Optimization of accelerator performance parameters is limited by numerous trade-offs and finding the appropriate balance between optimization goals for an unknown system is challenging to achieve. Here we show that multi-objective Bayesian…

Accelerator Physics · Physics 2023-03-29 F. Irshad , C. Eberle , F. M. Foerster , K. v. Grafenstein , F. Haberstroh , E. Travac , N. Weisse , S. Karsch , A. Döpp

Tuning parameters in model predictive control (MPC) presents significant challenges, particularly when there is a notable discrepancy between the controller's predictions and the actual behavior of the closed-loop plant. This mismatch may…

Systems and Control · Electrical Eng. & Systems 2024-10-11 Sebastian Hirt , Andreas Höhl , Joachim Schaeffer , Johannes Pohlodek , Richard D. Braatz , Rolf Findeisen

This paper proposes an automatic controller tuning framework based on linear optimal control combined with Bayesian optimization. With this framework, an initial set of controller gains is automatically improved according to a pre-defined…

Robotics · Computer Science 2017-09-21 Alonso Marco , Philipp Hennig , Jeannette Bohg , Stefan Schaal , Sebastian Trimpe

We provide a method to solve optimization problem when objective function is a complex stochastic simulator of an urban transportation system. To reach this goal, a Bayesian optimization framework is introduced. We show how the choice of…

Computation · Statistics 2019-01-15 Laura Schultz , Vadim Sokolov

When applying Machine Learning techniques to problems, one must select model parameters to ensure that the system converges but also does not become stuck at the objective function's local minimum. Tuning these parameters becomes a…

Machine Learning · Statistics 2017-11-16 Lawrence Stewart , Mark Stalzer

Particle-in-cell simulations are among the most essential tools for the modeling and optimization of laser-plasma accelerators, since they reproduce the physics from first principles. However, the high computational cost associated with…

Automated chemical synthesis, materials fabrication, and spectroscopic physical measurements often bring forth the challenge of process trajectory optimization, i.e., discovering the time dependence of temperature, electric field, or…

Disordered Systems and Neural Networks · Physics 2022-06-28 Mani Valleti , Rama K. Vasudevan , Maxim A. Ziatdinov , Sergei V. Kalinin

We propose a performance-based autotuning method for cascade control systems, where the parameters of a linear axis drive motion controller from two control loops are tuned jointly. Using Bayesian optimization as all parameters are tuned…

Systems and Control · Electrical Eng. & Systems 2021-01-22 Mohammad Khosravi , Varsha Behrunani , Piotr Myszkorowski , Roy S. Smith , Alisa Rupenyan , John Lygeros

Bayesian optimization through Gaussian process regression is an effective method of optimizing an unknown function for which every measurement is expensive. It approximates the objective function and then recommends a new measurement point…

Machine Learning · Statistics 2017-05-17 Hildo Bijl , Thomas B. Schön , Jan-Willem van Wingerden , Michel Verhaegen

Most machine learning methods require careful selection of hyper-parameters in order to train a high performing model with good generalization abilities. Hence, several automatic selection algorithms have been introduced to overcome tedious…

Machine Learning · Computer Science 2020-01-17 Raju Ram , Sabine Müller , Franz-Josef Pfreundt , Nicolas R. Gauger , Janis Keuper

Sampling-based planning is the predominant paradigm for motion planning in robotics. Most sampling-based planners use a global random sampling scheme to guarantee probabilistic completeness. However, most schemes are often inefficient as…

Robotics · Computer Science 2020-01-22 Tin Lai , Philippe Morere , Fabio Ramos , Gilad Francis

Electron ptychography provides new opportunities to resolve atomic structures with deep sub-angstrom spatial resolution and studying electron-beam sensitive materials with high dose efficiency. In practice, obtaining accurate ptychography…

Materials Science · Physics 2022-04-26 Michael C. Cao , Zhen Chen , Yi Jiang , Yimo Han

In current accelerators, numerous parameters and monitored values are to be adjusted and evaluated, respectively. In addition, fine adjustments are required to achieve the target performance. Therefore, the conventional…

Accelerator Physics · Physics 2024-01-29 Gaku Mitsuka , Shinnosuke Kato , Naoko Iida , Takuya Natsui , Masanori Satoh

Bayesian optimisation is a powerful tool to solve expensive black-box problems, but fails when the stationary assumption made on the objective function is strongly violated, which is the case in particular for ill-conditioned or…

Machine Learning · Statistics 2019-12-06 Victor Picheny , Sattar Vakili , Artem Artemev

Machine learning algorithms frequently require careful tuning of model hyperparameters, regularization terms, and optimization parameters. Unfortunately, this tuning is often a "black art" that requires expert experience, unwritten rules of…

Machine Learning · Statistics 2012-08-30 Jasper Snoek , Hugo Larochelle , Ryan P. Adams

Controller tuning and parameter optimization are crucial in system design to improve closed-loop system performance. Bayesian optimization has been established as an efficient model-free controller tuning and adaptation method. However,…

Systems and Control · Electrical Eng. & Systems 2024-04-24 Christopher König , Raamadaas Krishnadas , Efe C. Balta , Alisa Rupenyan

This paper focuses on Bayesian Optimization in combinatorial spaces. In many applications in the natural science. Broad applications include the study of molecules, proteins, DNA, device structures and quantum circuit designs, a on…

Machine Learning · Computer Science 2020-11-13 Tony C. Wu , Daniel Flam-Shepherd , Alán Aspuru-Guzik

This paper proposes novel noise-free Bayesian optimization strategies that rely on a random exploration step to enhance the accuracy of Gaussian process surrogate models. The new algorithms retain the ease of implementation of the classical…

Machine Learning · Computer Science 2024-07-18 Hwanwoo Kim , Daniel Sanz-Alonso

We use Bayesian optimization in combination with three-dimensional particle-in-cell simulations to determine the optimal laser and plasma parameters that, for a given laser pulse energy, maximize the cut-off energy of an electron beam…

Plasma Physics · Physics 2025-09-16 P. Valenta , T. Zh. Esirkepov , J. D. Ludwig , S. C. Wilks , S. V. Bulanov