摘要:

AbstractA 4×4‐system of integral equations for the Fourier transformed boundary values of the normal derivatives of the wave functions defined in the four quadrants ofR2‐space is derived. This system results from the scalar transmission problem with continuous passage of the boundary values of the total wave‐fields and of the weighted normal derivatives corresponding to the case of magnetically polarized fields. Several equivalent systems of integral equations are deduced then which show that Banach's fixed point principle may be applied at least for slightly differing media in the four quadrants. The method, which is equivalent to a compatibility condition for holomorphic functions, may be generalized to the case of the scalar transmission problem for octants inR3‐space. There a 12 × 12‐system of integral equations for the Fourier transformed normal derivatives on the quarter‐plane faces i

ISSN:0170-4214    

DOI:10.1002/mma.1670080112

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractSome specific functional spaces are required for the study of Norton‐Hoff materials. For this purpose we establish here a Korn's inequality and miscellaneous results of duality, traces, density and orthogonalit

ISSN:0170-4214    

DOI:10.1002/mma.1670080113

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA scheme for the simulation of solutions of the Boltzmann equation derived by Nanbu is investigated. Rigorous results concerning questions of justification, the computation effort and the energy fluctuations are presented.

ISSN:0170-4214    

DOI:10.1002/mma.1670080114

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractWe investigate a system of reaction‐diffusion equations which model the spread of a bacterial infection in a human population. A decoupling technique together with global bifurcation theory is used to study the steady‐state solutions of the system. The asymptotic behaviour of solutions is discussed by using sub and subersolutions and the quasimonotonicity of the sys

ISSN:0170-4214    

DOI:10.1002/mma.1670080115

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe paper considers a system of differential equations with impulse perturbations at fixed moments in time of the formwherexϵRn, ε is a small parameter,Sufficient conditions have been found for existence of the periodic solution of the given system in the critical and non‐critical ca

ISSN:0170-4214    

DOI:10.1002/mma.1670080116

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA communication system for pulse‐amplitude‐modulated signals is considered whose impulse response is bandlimited. For a certain class of sampling errors the worst case is investigated where the sampling error of the system is such that the least mean square transmission error achieved by a suitable choice of the impulse response becomes maximal. This problem is dualized in the sense of two person game theory and thereby transferred to an equivalent approximation problem for whose solution a necessary and sufficient condition is given and applied to special ca

ISSN:0170-4214    

DOI:10.1002/mma.1670080117

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractIn biology, a cline is defined as a usually gradual change in gene frequency or phenotype of a population in equilibrium, from one place to another.We define a cline as a nonconstant stable steady state solution. However, for the model studied in this paper, these two definitions coincide: a nonconstant stable steady state solution is necessarily monotone. It is proved that for small values of the penetrability of the barrier, exactly two clines exist.Since we prove that the Ω‐limit set of any initial condition is a steady state solution, the information thus obtained yields a rather complete understanding of the qualitative behaviour of the solutions of the evolution problem under considerati

ISSN:0170-4214    

DOI:10.1002/mma.1670080118

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractWe give sufficient conditions for the nonlinear stability of a, possibly non‐smooth, spatially homogeneous Vlasov‐Poisson flow.Research partially supported by Italian CNR and Ministero della Pubblica Istruzi

ISSN:0170-4214    

DOI:10.1002/mma.1670080119

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractIn this article the existence and the uniqueness of a Rayleigh surface wave propagating along the free boundary of a transversely isotropic elastic half space are proved by a spectral method.

ISSN:0170-4214    

DOI:10.1002/mma.1670080120

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe existence and uniqueness are established for the solution of the equation of transfer of polarized light in a homogeneous atmosphere of finite optical thickness, assuming reflection by the planetary surface. A generalLp‐space formulation is adopted. The boundary value problem is first written as a vector‐valued integral equation. Using monotonicity properties of the spectral radii of the integral operators involved as well as recent half‐range completeness results for kinetic equations with reflective boundary conditions, the present results follow as a coro

ISSN:0170-4214    

DOI:10.1002/mma.1670080121

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY