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Related papers: Feedback control of unstable cellular solidificati…

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We introduce a discrete linear lossy system with an embedded "hot spot" (HS), i.e., a site carrying linear gain and complex cubic nonlinearity. The system can be used to model an array of optical or plasmonic waveguides, where selective…

Optics · Physics 2016-11-26 Boris A. Malomed , Edwin Ding , K. W. Chow , S. K. Lai

We study spacing selection in directional solidification of Al-Cu alloys under transient growth conditions. New experimental results are presented which reveal that dendritic spacing versus solidification rate evolves in an almost step-wise…

Materials Science · Physics 2010-02-09 Morteza Amoorezaei , Sebastian Gurevich , Nikolas Provatas

We demonstrate that time-delayed feedback control can be improved by adaptively tuning the feedback gain. This adaptive controller is applied to the stabilization of an unstable fixed point and an unstable periodic orbit embedded in a…

Adaptation and Self-Organizing Systems · Physics 2016-08-10 Judith Lehnert , Philipp Hövel , Valentin Flunkert , Peter Yu. Guzenko , Alexander L. Fradkov , Eckehard Schöll

Extended time-delay auto-synchronization (ETDAS) is a promising technique for stabilizing unstable periodic orbits in low-dimensional dynamical systems. The technique involves continuous feedback of signals delayed by multiples of the…

chao-dyn · Physics 2009-10-28 Michael E. Bleich , Joshua E. S. Socolar

Local bifurcation control is a topic of fundamental importance in the field of nonlinear dynamical systems. We discuss an original example within the context of storage-ring free-electron laser physics by presenting a new model that enables…

Optics · Physics 2008-11-26 Giovanni De Ninno , Duccio Fanelli

We explore numerically the morphological patterns of thermo-diffusive instabilities in combustion fronts with a continuum fuel source, within a range of Lewis numbers and ignition temperatures, focusing on the cellular regime. For this…

Fluid Dynamics · Physics 2017-03-08 Hossein Azizi , Sebastian Gurevich , Nikolas Provatas

We show that Pyragas delayed feedback control can stabilize an unstable periodic orbit (UPO) that arises from a generic subcritical Hopf bifurcation of a stable equilibrium in an n-dimensional dynamical system. This extends results of…

Chaotic Dynamics · Physics 2015-05-19 Genevieve Brown , Claire M. Postlethwaite , Mary Silber

Adaptive sampling results in dramatic improvements in the recovery of sparse signals in white Gaussian noise. A sequential adaptive sampling-and-refinement procedure called Distilled Sensing (DS) is proposed and analyzed. DS is a form of…

Statistics Theory · Mathematics 2010-05-31 Jarvis Haupt , Rui Castro , Robert Nowak

We use three-dimensional phase-field simulations to investigate the dynamics of the two-phase composite patterns formed upon during solidification of eutectic alloys. Besides the spatially periodic lamellar and rod patterns that have been…

Materials Science · Physics 2010-06-01 Andrea Parisi , Mathis Plapp

We study the modulational instability induced by periodic variations of group-velocity dispersion in the proximity of the zero dispersion point. Multiple instability peaks originating from parametric resonance coexist with the conventional…

Optics · Physics 2023-07-19 Andrea Armaroli , Fabio Biancalana

Eigenstate phases such as the discrete time crystal exhibit an inherent instability upon the coupling to an environment, which restores equipartition of energy and therefore acts against the protecting nonergodicity. Here, we demonstrate…

Quantum Physics · Physics 2019-02-19 Leon Droenner , Regina Finsterhölzl , Markus Heyl , Alexander Carmele

Dynamic feedback linearization-based methods allow us to design control algorithms for a fairly large class of nonlinear systems in continuous time. However, this feature does not extend to their sampled counterparts, i.e., for a given…

Systems and Control · Electrical Eng. & Systems 2024-06-04 Ashutosh Jindal , Florentina Nicolau , David Martin Diego , Ravi Banavar

This paper studies the exponential stabilization on infinite dimensional system with impulse controls, where impulse instants appear periodically. The first main result shows that exponential stabilizability of the control system with a…

Optimization and Control · Mathematics 2021-05-13 Qishu Yan , Huaiqiang Yu

We introduce a system with one or two amplified nonlinear sites ("hot spots", HSs) embedded into a two-dimensional linear lossy lattice. The system describes an array of evanescently coupled optical or plasmonic waveguides, with gain…

Pattern Formation and Solitons · Physics 2015-06-19 Edwin Ding , A. Y. S. Tang , K. W. Chow , Boris A. Malomed

Directional solidification of water-based solutions has emerged as a versatile technique for templating hierarchical porous materials. However, the underlying mechanisms of pattern formation remain incompletely understood. In this work, we…

Materials Science · Physics 2026-03-20 Kaihua Ji , Alain Karma

We study the dynamics of a mean-field Ising model whose coupling depends on the magnetization via a linear feedback function. A key feature of this linear feedback Ising model (FIM) is the possibility of temperature-induced bistability,…

Statistical Mechanics · Physics 2026-03-31 Yi-Ping Ma , Ivan Sudakow , P. L. Krapivsky , Sergey A. Vakulenko

Numerous experimental data on the rapid solidification of binary systems exhibit the formation of metastable solid phases with the initial (nominal) chemical composition. This fact is explained by complete solute trapping leading to…

Materials Science · Physics 2009-11-13 Peter Galenko

We study the long-time dynamics of hexagonal directional-solidification patterns in bulk samples of a transparent eutectic alloy using an optical method which permits real-time observation of the growth front. A slow dilatation of the…

Pattern Formation and Solitons · Physics 2008-09-12 Mikael Perrut , Silvère Akamatsu , Sabine Bottin-Rousseau , Gabriel Faivre

For linear control systems, the usual state feedback stabilizability has two components: one is a continuous observation mode (i.e., to observe solutions continuously in time), and the other is a class of feedback laws (which is usually the…

Optimization and Control · Mathematics 2022-08-29 Hanbing Liu , Gengsheng Wang , Huaiqiang Yu

We consider the problem of output feedback controller sparsification for systems with parametric uncertainties. We develop an optimization scheme that minimizes the performance deterioration caused by the sparsification process, while…

Optimization and Control · Mathematics 2018-05-16 Reza Arastoo , MirSaleh Bahavarnia