Results 51 to 60 of about 18,923 (199)

Poisson Structures for PDEs Associated with Diffeomorphism Groups [PDF]

, 2004
We study Poisson and Lie-Poisson structures on the diffeomorphism groups with a smooth metric spray in connection with dynamics of nonlinear PDEs. In particular, we provide a precise analytic sense in which the time t map for the Euler equations of an ...
Vasylkevych, Sergiy
core   +1 more source

Front Propagation Through a Perforated Wall

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT We consider a bistable reaction– diffusion equation ut=Δu+f(u)$u_t=\Delta u +f(u)$ on RN${\mathbb {R}}^N$ in the presence of an obstacle K$K$, which is a wall of infinite span with many holes. More precisely, K$K$ is a closed subset of RN${\mathbb {R}}^N$ with smooth boundary such that its projection onto the x1$x_1$‐axis is bounded and that ...
Henri Berestycki, François Hamel, Hiroshi Matano   +2 more
wiley   +1 more source

New Applications of a Kind of Infinitesimal-Operator Lie Algebra

Advances in Mathematical Physics, 2016
Applying some reduced Lie algebras of Lie symmetry operators of a Lie transformation group, we obtain an invariant of a second-order differential equation which can be generated by a Euler-Lagrange formulism.
Honwah Tam, Yufeng Zhang, Xiangzhi Zhang
doaj   +1 more source

Nonsilting transport characteristics of coal slurry in a deep underground fluidization conveying pipeline under the action of a guide vane swirler

Deep Underground Science and Engineering, EarlyView.
Aiming at the scientific frontiers of in situ fluidized mining of deep resources, a deep coal fluidized pipeline lifting system based on hydraulic conveying has been proposed. To solve the issue of particle sedimentation of large particles in horizontal connection sections, a solution involving the installation of guide vane‐type swirlers in the ...
Jiusheng Bao, Shaodi Zhao, Yan Yin, Zhongbin Wang, Shuai Liu, Shirong Ge   +5 more
wiley   +1 more source

A Geometric Interpretation for the Algebraic Properties of Second‐Order Ordinary Differential Equations

Mathematical Methods in the Applied Sciences, Volume 48, Issue 6, Page 6912-6917, April 2025.
ABSTRACT Nowadays, a substantial portion of investigations concerning the symmetry analysis of differential equations predominantly adhere to a framework comprising the following key procedures: (i) the derivation of symmetries, (ii) the determination of an optimal system, (iii) the utilization of these symmetries to construct invariants or ...
A. Paliathanasis, S. Moyo, P. G. L. Leach   +2 more
wiley   +1 more source

Weak Solutions for a Class of Nonlocal Singular Problems Over the Nehari Manifold

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT In this paper, we consider a nonlocal model of dilatant non‐Newtonian fluid with a Dirichlet boundary condition. By using the Nehari manifold and fibering map methods, we obtain the existence of at least two weak solutions, with sign information.
Zhenfeng Zhang, Calogero Vetro, Tianqing An   +2 more
wiley   +1 more source

Hamilton-Pontryagin Integrators on Lie Groups [PDF]

, 2007
In this thesis structure-preserving time integrators for mechanical systems whose configuration space is a Lie group are derived from a Hamilton-Pontryagin (HP) variational principle.
Bou-Rabee, Nawaf Mohammed
core   +1 more source

A Variational Problem and Classification Theorem for Extremal Hypersurfaces in the Space Form

Journal of Mathematics, 2022
The classification of the isoparametric extremal hypersurfaces in the space form is obtained in this paper. We also derived the Euler-Lagrange equation for extremal hypersurface and obtained Simons’ type integral inequality.
Yu-Chung Chang
doaj   +1 more source

General Variational Formulation of Axisymmetric Capillary Bridges: Modeling Contact Angle Hysteresis and Capillary Forces

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT This work presents a general framework for deriving the Young–Laplace equation and the Young's equations for an axisymmetric capillary bridge between two parallel plates by minimizing the system's total energy. These Young's equations naturally emerge as boundary conditions associated with the Young–Laplace equation.
Olivier Millet, Antoine Moreau, Antoine Logerot, Marc Médale   +3 more
wiley   +1 more source

Adaptive Sliding Mode Control Design for Interval Type‐2 T–S Fuzzy Systems With Time Delay: An Event‐Triggered Approach

International Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT In this work, a new event‐triggered adaptive first‐order sliding mode control method is proposed for nonlinear systems with constant time delays, modeled by interval type‐2 Takagi–Sugeno (T–S) fuzzy systems. To handle matched disturbances with unknown upper bounds, a non‐overestimating adaptation strategy for the control coefficient is ...
Rodrigo Possidonio Noronha, Ginalber L. O. Serra   +1 more
wiley   +1 more source