Results 91 to 100 of about 3,082 (261)

Controlling the dynamics of Burgers equation with a high-order nonlinearity

International Journal of Mathematics and Mathematical Sciences, 2004
We investigate analytically as well as numerically Burgers equation with a high-order nonlinearity (i.e., ut=νuxx−unux+mu+h(x)). We show existence of an absorbing ball in L2[0,1] and uniqueness of steady state solutions for all integer n≥1.
Nejib Smaoui
doaj   +1 more source

Time Domain Finite Element Method for Maxwell’s Equations

IEEE Access, 2019
In this paper, we discuss a time domain finite element method for the approximate solution of Maxwell's equations. A weak formulation is derived for the electric and magnetic fields with appropriate initial and boundary conditions, and the problem is ...
Asad Anees, Lutz Angermann
doaj   +1 more source

Vibration Attenuation of Cantilever Beam Using Electromagnetic Delayed Feedback

International Journal of Mechanical System Dynamics, EarlyView.
ABSTRACT This study presents a combined analytical and numerical investigation of a single‐input single‐output delayed feedback controller designed to suppress vibrations in a cantilever beam actuated by an electromagnet positioned beneath its free end. An analytical model was developed using the linearized equation of motion for a transversely excited
Mohammad Alabdullah, Khaled Alhazza
wiley   +1 more source

Inertial‐Based LQG Control: A New Look at Inverted‐Pendulum Stabilization

International Journal of Mechanical System Dynamics, EarlyView.
ABSTRACT Linear‐quadratic Gaussian (LQG) control is a well‐established method for optimal control through state estimation, particularly in stabilizing an inverted pendulum on a cart. In standard laboratory setups, sensor redundancy enables direct measurement of configuration variables using displacement sensors and rotary encoders. However, in outdoor
Daniel Engelsman, Itzik Klein
wiley   +1 more source

A Coupled Extended Finite Element–Cohesive Zone Model for Hydraulic Fracture Propagation Under Poroelastic Effects Across Different Propagation Regimes

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT Numerical simulation of hydraulic fracturing remains challenging due to the strong coupling between geomechanics and fluid flow when modelling multiple physical mechanisms of rock deformation, fracture evolution and fluid leak‐off. This study develops a coupled hydraulic fracture propagation framework that combines the extended finite element ...
Ran Tao, Juliana Y. Leung, Samer Adeeb
wiley   +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

Automated Tuning of PID Controllers Using a Generalized Discrete PID Structure With Particle Swarm Optimization

IEEE Access
Proportional-Integral-Derivative (PID) controllers remain a widely adopted solution in the field of control systems due to their simplicity, flexibility, and ability to control a wide range of processes. Despite their success in various applications, PID
Abdul Aziz Al Barazi, Ercan Aykut
doaj   +1 more source

Overshooting of Hypoplastic Models With Intergranular Strain: Manifestation, Implications and Remedy

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT Intergranular strain extensions of hypoplasticity (IGS, ISA, GIS) are widely used to model small‐strain and cyclic soil behaviour. However, recent studies and our own simulations reveal that these models can exhibit stress overshooting not only under repeated small loading cycles but also during monotonic loading.
Jan Machaček, Merita Tafili, Carlos Grandas Tavera   +2 more
wiley   +1 more source

QUASI-OPTIMALITY IN THE BACKWARD EULER-GALERKIN METHOD FOR LINEAR PARABOLIC PROBLEMS

, 2014
We analyse the backward Euler-Galerkin method for linear parabolic problems, looking for quasi-optimality results in the sense of C a's Lemma. We cast the problem into the framework given by the inf-sup theory, and we analyse the spatial discretization, the discretization in time and the topic of varying the spatial discretization separately ...
openaire   +1 more source

Epistemic and aleatoric uncertainty quantification in weather and climate models

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Aleatoric and epistemic uncertainties over time on weather and climate time‐scales, estimated through ensembles that sample aleatoric and epistemic uncertainty using Bayesian neural networks for parameterisations in the Lorenz 1996 model. The spread shows the 16th and 84th percentiles.
Laura A. Mansfield, Hannah M. Christensen   +1 more
wiley   +1 more source