Results 131 to 140 of about 274,981 (281)

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

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

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

Hölder Regularity of the Solutions of Fredholm Integral Equations on Upper Ahlfors Regular Sets

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT We extend to the context of metric measured spaces, with a measure that satisfies upper Ahlfors growth conditions, the validity of (generalized) Hölder continuity results for the solution of a Fredholm integral equation of the second kind. Here we note that upper Ahlfors growth conditions include also cases of nondoubling measures.
Massimo Lanza de Cristoforis   +1 more
wiley   +1 more source

Existence of Solution for Two Classes of Quasilinear Systems Defined on a Nonreflexive Orlicz–Sobolev Spaces

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT This paper proves the existence of nontrivial solution for two classes of quasilinear systems of the type −ΔΦ1u=Fu(x,u,v)+λRu(x,u,v)inΩ−ΔΦ2v=−Fv(x,u,v)−λRv(x,u,v)inΩu=v=0on∂Ω$$ \left\{\begin{array}{l}\hfill -{\Delta}_{\Phi_1}u={F}_u\left(x,u,v\right)+\lambda {R}_u\left(x,u,v\right)\kern0.1832424242424242em \mathrm{in}\kern0.3em \Omega ...
Lucas da Silva, Marco Souto
wiley   +1 more source

Exploring Asymptotic Normality in Multinomial Models

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT Among the methods for analyzing categorical outcomes, the multinomial model offers a robust framework for examining the dependence between a multi‐category response variable and a set of explanatory variables. Its flexibility, versatility, and broad applicability across diverse fields make it a valuable tool, as it does not impose strict ...
Célia Nunes   +3 more
wiley   +1 more source

Linear Toroidal‐Inertial Waves on A Differentially Rotating Sphere with Application to Helioseismology: Modeling, Forward and Inverse Problems

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT This paper develops a mathematical framework for interpreting observations of solar inertial waves in an idealized setting. Under the assumption of purely toroidal linear waves on the sphere, the stream function of the flow satisfies a fourth‐order scalar equation.
Tram Thi Ngoc Nguyen   +3 more
wiley   +1 more source

A Numerical Alternative to MR Thermometry for Safety Validation of Multi‐Channel RF Transmit Coils

open access: yesMagnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose This study proposes a numerical technique to estimate peak local specific absorption rate (SAR) uncertainty of multi‐channel RF coils during the process of safety validation as an alternative to experimental temperature and electric‐field measurements, and demonstrates its use to enable human studies at 10.5 T.
Alireza Sadeghi‐Tarakameh   +14 more
wiley   +1 more source

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