Results 111 to 120 of about 21,965 (264)

Equivalences of Nonlinear Higher Order Fractional Differential Equations With Integral Equations

open access: yesMathematical Methods in the Applied Sciences, Volume 48, Issue 6, Page 6930-6942, April 2025.
ABSTRACT Equivalences of initial value problems (IVPs) of both nonlinear higher order (Riemann–Liouville type) fractional differential equations (FDEs) and Caputo FDEs with the corresponding integral equations are studied in this paper. It is proved that the nonlinearities in the FDEs can be L1$$ {L}^1 $$‐Carathéodory with suitable conditions.
Kunquan Lan
wiley   +1 more source

Space‐Time FEM Solution of Dynamic Contact Problem With Discontinuous Velocity for Multiple Impact of Deformed Bar Using PDAS Method

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT A class of one‐dimensional impact and dynamic contact problems taking into account non‐smooth velocities is studied. The new space‐time finite element approximation of dynamic variational inequalities is suggested. The non‐smooth solution for the impact of an obstacle by an elastic bar and its energy conservation under persistency conditions ...
Victor A. Kovtunenko   +2 more
wiley   +1 more source

Interaction of Dirac δ$$ \delta $$‐Waves in the Inviscid Levine and Sleeman Chemotaxis Model

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT This article investigates interactions of δ$$ \delta $$‐shock waves in the inviscid Levine and Sleeman chemotaxis model ut−λ(uv)x=0$$ {u}_t-\lambda {(uv)}_x=0 $$, vt−ux=0$$ {v}_t-{u}_x=0 $$. The analysis employs a distributional product and a solution concept that extends the classical solution concept.
Adelino Paiva
wiley   +1 more source

Analytical Solutions for the Cardiac Extracellular‐Membrane‐Intracellular Model

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT The cardiac extracellular‐membrane‐intracellular (EMI) model is a novel mathematical framework for cardiac electrophysiology simulations. The cardiac EMI model provides a more detailed description of the heart's electrical activity compared to traditional monodomain and bidomain models, potentially making it better‐suited for understanding the
Carlos Ballesteros   +2 more
wiley   +1 more source

Subspace methods for Eigenvalue problems

open access: yes, 2003
This thesis treats a number of aspects of subspace methods for various eigenvalue problems. Vibrations and their corresponding eigenvalues (or frequencies) arise in science, engineering, and daily life. Matrix eigenvalue problems come from a large number of areas, such as chemistry, mechanics, dynamical systems, Markov chains, magneto-hydrodynamics ...
openaire   +2 more sources

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

open access: yesMathematical 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   +2 more
wiley   +1 more source

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

open access: yesMathematical 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

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

open access: yesMathematical 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   +2 more
wiley   +1 more source

Dynamic Contrast Enhanced—Magnetic Resonance Fingerprinting (DCE‐MRF) Improves Detection of Induced Vascular Perfusion Reduction in a Mouse Breast Cancer Model

open access: yesMagnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose Dynamic contrast‐enhanced MRI (DCE‐MRI) can assess tumor perfusion using pharmacokinetic models. However, poor DCE‐MRI reproducibility from reliance on conventional T1‐weighted MRI has limited clinical translation. We evaluated whether Dynamic Contrast Enhanced‐Magnetic Resonance Fingerprinting (DCE‐MRF), which directly generates ...
Christina J. MacAskill   +15 more
wiley   +1 more source

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