Results 111 to 120 of about 138,862 (288)

Duality for Evolutionary Equations With Applications to Null Controllability

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT We study evolutionary equations in exponentially weighted L2$$ {\mathrm{L}}^2 $$‐spaces as introduced by Picard in 2009. First, for a given evolutionary equation, we explicitly describe the ν$$ \nu $$‐adjoint system, which turns out to describe a system backwards in time. We prove well‐posedness for the ν$$ \nu $$‐adjoint system. We then apply
Andreas Buchinger, Christian Seifert
wiley   +1 more source

On the Mean‐Field Limit of Consensus‐Based Methods

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT Consensus‐based optimization (CBO) employs a swarm of particles evolving as a system of stochastic differential equations (SDEs). Recently, it has been adapted to yield a derivative free sampling method referred to as consensus‐based sampling (CBS). In this paper, we investigate the “mean‐field limit” of a class of consensus methods, including
Marvin Koß, Simon Weissmann, Jakob Zech
wiley   +1 more source

Existence and uniqueness theorem of associated solutions of the stochastic differential system with measures

open access: yesЖурнал Белорусского государственного университета: Математика, информатика, 2018
The Cauchy problem for stochastic differential system with measures is considered in the paper. Finite-difference with averaging system of stochastic differential equations with correspondence to Cauchy problem is investigated.
Artsiom Y. Rusetski
doaj  

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

Existence of Solutions of Semilinear Wave Equations With Time‐Dependent Propagation Speed and Time Derivative Nonlinearity

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT Consider wave equations with time derivative nonlinearity and time‐dependent propagation speed which are generalized versions of the wave equations in the Friedmann–Lemaître–Robertson–Walker (FLRW) spacetime, the de Sitter spacetime and the anti‐de Sitter space time.
Kimitoshi Tsutaya, Yuta Wakasugi
wiley   +1 more source

Matsumura‐Type Estimates and Global Solutions of a Fractional Wave Equation With Nonlocal Nonlinearity

open access: yesMathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT The main results of this paper are the global existence and long time behavior of solutions of a fractional wave equation with a nonlocal nonlinearity. The techniques in this work rely on norm estimates of the solutions of εutt+ut+(−Δ)βu=0,u(0,x)=φ(x),ut(0,x)=ψ(x),$$ \varepsilon {u}_{tt}+{u}_t+{\left(-\Delta \right)}^{\beta }u=0,\kern1em u ...
Ibrahim Ahmad Suleman, Mokhtar Kirane
wiley   +1 more source

A Parallelized 3D Geomechanical Solver for Fluid‐Induced Fault Slip in Poroelastic Media

open access: yesInternational Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT We present a fully implicit formulation of coupled fluid flow and geomechanics for fluid injection/withdrawal in fractured reservoirs in the context of CO2$\textrm {CO}_2$ storage. Utilizing a Galerkin finite‐element approach, both flow and poroelasticity equations are discretized on a shared three‐dimensional mesh.
Emil Rinatovich Gallyamov   +4 more
wiley   +1 more source

Explicit‐Implicit Material Point Method for Dense Granular Flows With a Novel Regularized µ(I) Model

open access: yesInternational Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT The material point method (MPM) is widely employed to simulate granular flows. Although explicit time integration is favored in most current MPM implementations for its simplicity, it cannot rigorously incorporate the incompressible µ(I)‐rheology, an efficient model ubiquitously adopted in other particle‐based numerical methods. While operator‐
Hang Feng, Zhen‐Yu Yin
wiley   +1 more source

Applying Dynamics/Cost Parameter Continuation to the Optimal Guidance of Variable‐Speed Unicycle

open access: yesOptimal Control Applications and Methods, EarlyView.
(a) Classical parameter continuation method diverges. (b) Dynamics/cost parameter continuation method converges. ABSTRACT The problem of a variable‐speed unicycle guidance to the stationary target is considered. The vehicle should be guided to the origin while minimizing the energy loss due to the induced drag.
Gleb Merkulov   +2 more
wiley   +1 more source

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