Results 51 to 60 of about 29,939 (196)

RAMS: Residual‐Based Adversarial‐Gradient Moving Sample Method for Scientific Machine Learning in Solving Partial Differential Equations

Advanced Intelligent Discovery, EarlyView.
We propose a residual‐based adversarial‐gradient moving sample (RAMS) method for scientific machine learning that treats samples as trainable variables and updates them to maximize the physics residual, thereby effectively concentrating samples in inadequately learned regions.
Weihang Ouyang, Min Zhu, Wei Xiong, Si‐Wei Liu, Lu Lu   +4 more
wiley   +1 more source

On the limit cycles of planar discontinuous piecewise linear differential systems with a unique equilibrium

, 2017
This paper deals with planar discontinuous piecewise linear differential systems with two zones separated by a vertical straight line \begin{document}$ x = k $\end{document} . We assume that the left linear differential system ( \begin{document}$ x ) and
Shimin Li, J. Llibre
semanticscholar   +1 more source

Wearable exoskeleton robot control using radial basis function‐based fixed‐time terminal sliding mode with prescribed performance

Asian Journal of Control, EarlyView.
Abstract This paper tackles the problem of robust and accurate fixed‐time tracking in human–robot interaction and deals with uncertainties. This work introduces a control approach for a wearable exoskeleton designed specifically for rehabilitation tasks.
Mahmoud Abdallah, Yassine Kali, Maarouf Saad, Raouf Fareh, Maamar Bettayeb   +4 more
wiley   +1 more source

LOWER BOUNDS FOR THE MAXIMUM NUMBER OF LIMIT CYCLES OF DISCONTINUOUS PIECEWISE LINEAR DIFFERENTIAL SYSTEMS WITH A STRAIGHT LINE OF SEPARATION [PDF]

International Journal of Bifurcation and Chaos, 2013
In this paper, we provide a lower bound for the maximum number of limit cycles of planar discontinuous piecewise linear differential systems defined in two half-planes separated by a straight line. Here, we only consider nonsliding limit cycles. For those systems, the interior of any limit cycle only contains a unique equilibrium point or a unique ...
J. LLIBRE, M. A. TEIXEIRA, J. TORREGROSA
openaire   +4 more sources

A Cut Discontinuous Galerkin Method for Coupled Bulk-Surface Problems

, 2017
We develop a cut Discontinuous Galerkin method (cutDGM) for a diffusion-reaction equation in a bulk domain which is coupled to a corresponding equation on the boundary of the bulk domain. The bulk domain is embedded into a structured, unfitted background
Massing, Andre
core   +1 more source

Spatially resolved 23Na magnetic resonance dispersion measurement in porous media

The Canadian Journal of Chemical Engineering, EarlyView.
Quantitative 23Na MRI was employed to analyze dispersion in realistic core plug samples and was compared with the conventional breakthrough curve. 23Na MRI provided a more effective aassessment of core plug heterogeneity than the conventional method. Abstract Tracer tests are widely used in the petroleum industry to assess reservoir core plugs, relying
Rheya Rajeev, Mohammad Sadegh Zamiri, Andrés Ramírez Aguilera, Florea Marica, Laura Romero de Zerón, Bruce J. Balcom   +5 more
wiley   +1 more source

Limit cycles of discontinuous piecewise differential systems formed by linear centers in R2 and separated by two circles

Nonlinear Analysis: Real World Applications, 2021
We show that discontinuous planar piecewise differential systems formed by linear centers and separated by two concentric circles can have at most three limit cycles. Usually is a difficult problem to provide the exact upper bound that a class of differential systems can exhibit.
Anacleto, Maria Elisa, Llibre, Jaume, Valls, Claudia, Vidal, Claudio   +3 more
openaire   +3 more sources

Limit cycles of piecewise polynomial perturbations of higher dimensional linear differential systems [PDF]

Revista matemática iberoamericana, 2018
The averaging theory has been extensively employed for studying periodic solutions of smooth and nonsmooth differential systems. Here, we extend the averaging theory for studying periodic solutions a class of regularly perturbed non-autonomous $n ...
J. Llibre, D. Novaes, I. O. Zeli
semanticscholar   +1 more source

The Benjamin–Ono Equation in the Zero‐Dispersion Limit for Rational Initial Data: Generation of Dispersive Shock Waves

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT The leading‐order asymptotic behavior of the solution of the Cauchy initial‐value problem for the Benjamin–Ono equation in L2(R)$L^2(\mathbb {R})$ is obtained explicitly for generic rational initial data u0$u_0$. An explicit asymptotic wave profile uZD(t,x;ε)$u^\mathrm{ZD}(t,x;\epsilon)$ is given, in terms of the branches of the multivalued ...
Elliot Blackstone, Louise Gassot, Patrick Gérard, Peter D. Miller   +3 more
wiley   +1 more source

Disturbance‐Resilient Voltage/Power‐Quality Management for Islanded Inverters Using Self‐Tuning Type‐3 Fuzzy Controller

Energy Science &Engineering, EarlyView.
An adaptive fuzzy controller using an interval type‐3 fuzzy logic system replaces the SMC switching term to mitigate chattering while preserving global stability for islanded inverters. Simulations show lower THD, greater robustness to disturbances and parameter variations, and improved voltage‐tracking accuracy, with applicability to other uncertain ...
Man‐Wen Tian, Jun‐Bo Mao, Nurkhat Zhakiyev, Didar Yedilkhan, Ruslan Omirgaliyev, Du Changdong, Amirhossein Khosravi Sarvenoee, Ardashir Mohammadzadeh   +7 more
wiley   +1 more source