Results 81 to 90 of about 1,155,766 (245)

Asymptotics for the Spectrum of the Laplacian in Thin Bars with Varying Cross Sections

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT We consider spectral problems for the Laplace operator in 3D rod structures with a small cross section of diameter O(ε)$$ O\left(\varepsilon \right) $$, ε$$ \varepsilon $$ being a positive parameter. The boundary conditions are Dirichlet (Neumann, respectively) on the bases of this structure, and Neumann on the lateral boundary.
Pablo Benavent‐Ocejo, Delfina Gómez, Maria‐Eugenia Pérez‐Martínez   +2 more
wiley   +1 more source

Existence Analysis of a Three‐Species Memristor Drift‐Diffusion System Coupled to Electric Networks

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT The existence of global weak solutions to a partial‐differential‐algebraic system is proved. The system consists of the drift‐diffusion equations for the electron, hole, and oxide vacancy densities in a memristor device, the Poisson equation for the electric potential, and the differential‐algebraic equations for an electric network.
Ansgar Jüngel, Tuấn Tùng Nguyến
wiley   +1 more source

An Optimal Lower Eigenvalue System

Abstract and Applied Analysis, 2011
An optimal lower eigenvalue system is studied, and main theorems including a series of necessary and suffcient conditions concerning existence and a Lipschitz continuity result concerning stability are obtained.
Yingfan Liu
doaj   +1 more source

From Stability to Chaos: A Complete Classification of the Damped Klein‐Gordon Dynamics

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT We investigate the transition between stability and chaos in the damped Klein‐Gordon equation, a fundamental model for wave propagation and energy dissipation. Using semigroup methods and spectral criteria, we derive explicit thresholds that determine when the system exhibits asymptotic stability and when it displays strong chaotic dynamics ...
Carlos Lizama, Marina Murillo‐Arcila, Julio Puerta‐Fernández   +2 more
wiley   +1 more source

Caratheodory’s approximation for a type of Caputo fractional stochastic differential equations

Advances in Difference Equations, 2020
The Caratheodory approximation for a type of Caputo fractional stochastic differential equations is considered. As is well known, under the Lipschitz and linear growth conditions, the existence and uniqueness of solutions for some type of differential ...
Zhongkai Guo, Junhao Hu, Weifeng Wang
doaj   +1 more source

Trajectory Control of Manipulator Robots With Uncertainties: A Saturated Continuous Integral Sliding Mode Approach

International Journal of Mechanical System Dynamics, EarlyView.
ABSTRACT This study addresses the trajectory tracking control for manipulator robots with uncertainties. The main objective is to ensure that the robot follows a desired trajectory despite the presence of uncertainties/disturbances and considering control input constraints. The approach is developed in the framework of continuous integral sliding modes.
Emanuel Ortiz‐Ortiz, Juan Eduardo Velázquez‐Velázquez, Ramón Silva‐Ortigoza, Rosalba Galván‐Guerra   +3 more
wiley   +1 more source

The von Neumann Stability Analysis of the Fixed‐Stress Schemes in Poroelastodynamics

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT We investigate splitting schemes based on the fixed‐stress sequential approach for poroelastodynamic problems. To assess numerical stability, we perform the von Neumann stability analysis on several fixed‐stress schemes for poroelastodynamics, including staggered, stabilized, and iterative methods. Our analysis reveals that while the staggered
Jihoon Kim, Sanghyun Lee, Mary F. Wheeler   +2 more
wiley   +1 more source

On Improved Simpson-Type Inequalities via Convexity and Generalized Fractional Operators

Journal of Mathematics
In this work, we develop novel Simpson-type inequalities for mappings with convex properties by employing operators for tempered fractional integrals. These findings expand upon and refine classical results, including those linked to Riemann–Liouville ...
Areej A. Almoneef, Abd-Allah Hyder, Fatih Hezenci, Hüseyin Budak   +3 more
doaj   +1 more source

On the Convergence of Conjugate Gradient and GMRES Algorithms in the Forward Backward Sweep Method for Optimal Control

Optimal Control Applications and Methods, EarlyView.
Optimal control combines state and adjoint equations, which yield the state (x$$ x $$) and adjoint (lambda) variables as a function of the control variables (u$$ u $$). This structure allows us to design strategies for iteratively updating the control variable, based on conjugate gradient (CG) or GMRES algorithms.
N. Armengou‐Riera, N. Rabiei, A. Bijalwan, A. Rodríguez‐Ferran, J. J. Muñoz   +4 more
wiley   +1 more source

Comparative Analysis of the Performances of a Nonlinear Observer and Nonlinear Kalman Filters in the Presence of Non‐Gaussian Disturbances

International Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This paper focuses on state estimation for a fairly general class of systems, involving nonlinear functions and disturbances in both the process dynamics and output equations. A nonlinear observer that satisfies a H∞$$ {\boldsymbol{H}}_{\boldsymbol{\infty}} $$ disturbance attenuation constraint in addition to providing asymptotic stability in ...
Hamidreza Movahedi, Ali Zemouche, Rajesh Rajamani   +2 more
wiley   +1 more source