Displaying 341 – 360 of 555

Showing per page

L∞(L2) and L∞(L∞) error estimates for mixed methods for integro-differential equations of parabolic type

Ziwen Jiang (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

Error estimates in L∞(0,T;L2(Ω)), L∞(0,T;L2(Ω)2), L∞(0,T;L∞(Ω)), L∞(0,T;L∞(Ω)2), Ω in 2 , are derived for a mixed finite element method for the initial-boundary value problem for integro-differential equation u t = div { a u + 0 t b 1 u d τ + 0 t 𝐜 u d τ } + f based on the Raviart-Thomas space Vh x Wh ⊂ H(div;Ω) x L2(Ω). Optimal order estimates are obtained for the approximation of u,ut in L∞(0,T;L2(Ω)) and the associated velocity p in L∞(0,T;L2(Ω)2), divp in L∞(0,T;L2(Ω)). Quasi-optimal order estimates are obtained for the approximation...

L∞-Norm minimal control of the wave equation: on the weakness of the bang-bang principle

Martin Gugat, Gunter Leugering (2008)

ESAIM: Control, Optimisation and Calculus of Variations


For optimal control problems with ordinary differential equations where the L -norm of the control is minimized, often bang-bang principles hold. For systems that are governed by a hyperbolic partial differential equation, the situation is different: even if a weak form of the bang-bang principle still holds for the wave equation, it implies no restriction on the form of the optimal control. To illustrate that for the Dirichlet boundary control of the wave equation in general not even feasible...

Currently displaying 341 – 360 of 555