Asymptotic large- and short-time behavior of solutions of the linear dispersion equation μt = Uxxx in IR× IR＋, and its （2k＋l）th-order extensions are studied. Such a refined scattering is based on a ＂Hermit...Asymptotic large- and short-time behavior of solutions of the linear dispersion equation μt = Uxxx in IR× IR＋, and its （2k＋l）th-order extensions are studied. Such a refined scattering is based on a ＂Hermitian＂ spectral theory for a pair {B,B＊} of non self-adjoint rescaled operators展开更多
The aim of this paper is the introduction of a new approach to 3D modelling of elastic piecewise homogeneous media, in particular Earth crust and upper Mantle. The method is based on the principle of tomography with E...The aim of this paper is the introduction of a new approach to 3D modelling of elastic piecewise homogeneous media, in particular Earth crust and upper Mantle. The method is based on the principle of tomography with Earthquake as a source of the signal and receiver stations on the surface. The wave propagation in solid media is described by a system of three strongly coupled hyperbolic equations with piece - wise constant coefitients. The characteristic set and hi-characteristic curves of this system are computed in a homogeneous half-space with free boundary and the formulae of reflection and diffraction of the hi-characteristics on the internal boundaries of the media. Applications of the characteristic set and bi-eharacteristic curves for the inverse problem in geophysics and Earth modelling are given.展开更多
Aims and Scope The Journal of Computational Mathematics is published bi-monthly.It is an international journal covering all branches of modern computational mathematics such as numerical linear algebra,numerical optim...Aims and Scope The Journal of Computational Mathematics is published bi-monthly.It is an international journal covering all branches of modern computational mathematics such as numerical linear algebra,numerical optimization,computational geometry,numerical PDEs and inverse problems.Papers containing new ideas,creative approaches and/or innovative applications as well as invited reviews are expected to appear regularly in the journal.展开更多
Semi-linear n x n systems of the form Aδu/δ＋Bδ/δy=f can generally be solved, at least locally, provided data are imposed on non-characteristic curves. There are at most n characteristic curves and they are determ...Semi-linear n x n systems of the form Aδu/δ＋Bδ/δy=f can generally be solved, at least locally, provided data are imposed on non-characteristic curves. There are at most n characteristic curves and they are determined by the coefficient matrices on the left-hand sides of the equations. We consider cases where such problems become degenerate as a result of ambiguity associated with the definition of characteristic curves. In such cases, the existence of solutions requires restrictions on the data and solutions might not be unique.展开更多
文摘Asymptotic large- and short-time behavior of solutions of the linear dispersion equation μt = Uxxx in IR× IR＋, and its （2k＋l）th-order extensions are studied. Such a refined scattering is based on a ＂Hermitian＂ spectral theory for a pair {B,B＊} of non self-adjoint rescaled operators
文摘The aim of this paper is the introduction of a new approach to 3D modelling of elastic piecewise homogeneous media, in particular Earth crust and upper Mantle. The method is based on the principle of tomography with Earthquake as a source of the signal and receiver stations on the surface. The wave propagation in solid media is described by a system of three strongly coupled hyperbolic equations with piece - wise constant coefitients. The characteristic set and hi-characteristic curves of this system are computed in a homogeneous half-space with free boundary and the formulae of reflection and diffraction of the hi-characteristics on the internal boundaries of the media. Applications of the characteristic set and bi-eharacteristic curves for the inverse problem in geophysics and Earth modelling are given.
文摘Aims and Scope The Journal of Computational Mathematics is published bi-monthly.It is an international journal covering all branches of modern computational mathematics such as numerical linear algebra,numerical optimization,computational geometry,numerical PDEs and inverse problems.Papers containing new ideas,creative approaches and/or innovative applications as well as invited reviews are expected to appear regularly in the journal.
文摘Semi-linear n x n systems of the form Aδu/δ＋Bδ/δy=f can generally be solved, at least locally, provided data are imposed on non-characteristic curves. There are at most n characteristic curves and they are determined by the coefficient matrices on the left-hand sides of the equations. We consider cases where such problems become degenerate as a result of ambiguity associated with the definition of characteristic curves. In such cases, the existence of solutions requires restrictions on the data and solutions might not be unique.
