摘要:

AbstractThe local existence, uniqueness and regularity of solutions of the initial‐value problem for non‐stationary Navier–Stokes equations are studied via abstract Besov spaces. The assumptions about Ω the initial data and the external force are improved on by rather simple

ISSN:0170-4214    

DOI:10.1002/mma.1670150902

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe so‐called Timoshenko beam equation is a good linear model for the transverse vibrations of a homogeneous beam. Following the variational approach of Washizu, the governing equation is deduced in the case when the physical/geometrical parameters of the beam vary along its axis. The equation may not be studied by means of the iterated use of Fourier series. However, a convenient change of variables permits us to prove the well‐posedness of the associated Cauchy problem for a beam with sliding ends (the solution is intended in a mild sense). The proof is given in an abstract framew

ISSN:0170-4214    

DOI:10.1002/mma.1670150903

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractIn this paper we study the questions of the existence and uniqueness of the solutions for a thermoelastic system of equationsin a two‐dimensional domain, where both the viscosityvand the rigidityDare positive. It seems that such a system has up to now been considered in a one‐dimensional setting only. The change of dimensions enforces the growth conditions with respect to θ and the additional regularity of the data. The existence of solutions in the case of the Neumann boundary conditions for θ and some weak regularity of data is proved. Under stronger regularity conditions the uniqueness is also established. The system has an interpretation as a plate reinforced by a shape memory alloy (SMA) wire

ISSN:0170-4214    

DOI:10.1002/mma.1670150904

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractWe formulate certain problems in the optimal design of radiating structures such as multicriteria optimization problems. We review the basic background of such problems, prove the existence of Pareto optimal points, and give necessary conditions. We apply the latter to the numerical computation of optimal surface currents for the problem of simultaneously optimizing both the quality factor and the signal‐to‐noise ratio of a conformal ante

ISSN:0170-4214    

DOI:10.1002/mma.1670150905

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper deals with some mathematical aspects of magnetic resonance imaging (MRI). MRI is used in diagnostic medicine to measure and display the cross section of, for example, a human organ. In this paper we formulate the MRI‐reconstruction problem and solve it aftèr restating it as a moment problem in a Hilbert spa

ISSN:0170-4214    

DOI:10.1002/mma.1670150906

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

ISSN:0170-4214    

DOI:10.1002/mma.1670150901

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY