Results 31 to 40 of about 23,327 (265)

The Number of Limit Cycles of a Polynomial System on the Plane

open access: yesAbstract and Applied Analysis, 2013
We perturb the vector field x˙=-yC(x,y), y˙=xC(x,y) with a polynomial perturbation of degree n, where C(x,y)=(1-y2)m, and study the number of limit cycles bifurcating from the period annulus surrounding the origin.
Chao Liu, Maoan Han
doaj   +1 more source

The Investigation of Nonlinear Polynomial Control Systems

open access: yesМоделирование и анализ информационных систем, 2021
The paper considers methods for estimating stability using Lyapunov functions, which are used for nonlinear polynomial control systems. The apparatus of the Gro¨bner basis method is used to assess the stability of a dynamical system. A description of the
Sergei Nikolaevich Chukanov   +1 more
doaj   +1 more source

Projections of Polynomial Vector Fields and the Poincaré Sphere

open access: yesJournal of Differential Equations, 1997
Let \(p:\mathbb{R}^n\to\mathbb{R}^n\) be a homogeneous polynomial vector function, and let \(\rho:\mathbb{R}^n \to\mathbb{R}\) be a homogeneous polynomial of positive degree \(d\). The authors introduce the projection of \(p\) with respect to \(\rho\) by the formula \[ p^{\rho}(x)=- {\textstyle\frac{1}{d}} L_p(\rho)(x)x+\rho(x)p(x), \] where \(L_p(\rho)
Röhrl, Helmut, Walcher, Sebastian
openaire   +1 more source

Symbolic Computations of First Integrals for Polynomial Vector Fields [PDF]

open access: yesFoundations of Computational Mathematics, 2019
In this article we show how to generalize to the Darbouxian, Liouvillian and Riccati case the extactic curve introduced by J. Pereira. With this approach, we get new algorithms for computing, if it exists, a rational, Darbouxian, Liouvillian or Riccati first integral with bounded degree of a polynomial planar vector field.
Chèze, Guillaume, Combot, Thierry
openaire   +5 more sources

Poincaré Bifurcations of Two Classes of Polynomial Systems

open access: yesAbstract and Applied Analysis, 2013
Using bifurcation methods and the Abelian integral, we investigate the number of the limit cycles that bifurcate from the period annulus of the singular point when we perturb the planar ordinary differential equations of the form , with an arbitrary ...
Jing Wang, Shuliang Shui
doaj   +1 more source

Renormalization of vector fields with mass-like coupling in curved spacetime

open access: yesEuropean Physical Journal C: Particles and Fields, 2019
Using the method of covariant symbols we compute the divergent part of the effective action of the Proca field with non-minimal mass term. Specifically a quantum abelian vector field with a non-derivative coupling to an external tensor field in curved ...
C. Garcia-Recio, L. L. Salcedo
doaj   +1 more source

3D Mesh Model Classification with a Capsule Network

open access: yesAlgorithms, 2021
With the widespread success of deep learning in the two-dimensional field, how to apply deep learning methods from two-dimensional to three-dimensional field has become a current research hotspot.
Yang Zheng   +4 more
doaj   +1 more source

Topological enumeration of complex polynomial vector fields [PDF]

open access: yesErgodic Theory and Dynamical Systems, 2014
AbstractThe enumeration of combinatorial classes of the complex polynomial vector fields in$ \mathbb{C} $presented by K. Dias [Enumerating combinatorial classes of the complex polynomial vector fields in$ \mathbb{C} $.Ergod. Th. & Dynam. Sys. 33(2013), 416–440] is extended here to a closed form enumeration of combinatorial classes for degree$d ...
openaire   +3 more sources

Symbolic Regression and Multi‐Objective Optimization of the Flory–Huggins Interaction Parameter for Hydrogels

open access: yesAdvanced Engineering Materials, EarlyView.
We develop a data‐driven method to derive the mathematical expressions of the Flory–Huggins interaction parameter χ for the swelling behavior of temperature–responsive hydrogels. Starting from initial assumptions of χ, our workflow combines Bayesian optimization, Flory–Rehner theory, and symbolic regression to generate candidate χ expressions.
Yawen Wang   +2 more
wiley   +1 more source

An Exponential Formula for Polynomial Vector Fields

open access: yesAdvances in Mathematics, 1997
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire   +2 more sources

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