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991.
Martin Schechter 《Mathematische Nachrichten》1997,183(1):201-210
We study semilinear problems in which the nonlinear part is linear at infinity but behaves like a function intersecting many of the eigenvalues of the linear operator. The asymptotic linear operator can have a null space of any finite dimension. 相似文献
992.
In the present investigation, a Fourier analysis is used to study the phase and group speeds of a linearized, two‐dimensional shallow water equations, in a non‐orthogonal boundary‐fitted co‐ordinate system. The phase and group speeds for the spatially discretized equations, using the second‐order scheme in an Arakawa C grid, are calculated for grids with varying degrees of non‐orthogonality and compared with those obtained from the continuous case. The spatially discrete system is seen to be slightly dispersive, with the degree of dispersivity increasing with an decrease in the grid non‐orthogonality angle or decrease in grid resolution and this is in agreement with the conclusions reached by Sankaranarayanan and Spaulding (J. Comput. Phys., 2003; 184 : 299–320). The stability condition for the non‐orthogonal case is satisfied even when the grid non‐orthogonality angle, is as low as 30° for the Crank Nicolson and three‐time level schemes. A two‐dimensional wave deformation analysis, based on complex propagation factor developed by Leendertse (Report RM‐5294‐PR, The Rand Corp., Santa Monica, CA, 1967), is used to estimate the amplitude and phase errors of the two‐time level Crank–Nicolson scheme. There is no dissipation in the amplitude of the solution. However, the phase error is found to increase, as the grid angle decreases for a constant Courant number, and increases as Courant number increases. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
993.
平面非牛顿流体在m>1时的径向流动 总被引:1,自引:1,他引:0
讨论平面非牛顿流体(例如高粘度高含腊量的地下石油)在m>1时的径向流动.作者首先给出了问题的数学模型,它是退缩的自由边值问题.然后得到了该问题的近似问题古典解的存在唯一性.当油井边的压力梯度是常值函数时,该问题古典解的存在唯一性也得到了. 相似文献
994.
W. E. Hart 《Journal of Computational and Applied Mathematics》1992,40(3):285-296
We introduce a quasi-Newton update for nonlinear equations which have a Jacobian with sparse triangular factors and consider its application, through an algorithm of Deuflhard, to the solution of boundary value problems by multiple shooting. 相似文献
995.
S. K. Donaldson 《Journal of Geometry and Physics》1992,8(1-4):89-122
This paper investigates boundary value problems for Hermitian Yang—Mills equations over complex manifolds. The main result is the unique solubility of the Dirichlet problem for the Hermitian Yang—Mills equation. Connections with a number of topics are found, including the link with loop groups. 相似文献
996.
997.
中立型抛物方程解的强迫振动性 总被引:2,自引:0,他引:2
本文讨论中立型抛物方程解的强迫振动,其中Ω是Rn中具有光滑边界Ω的有界区域, 相似文献
998.
Nondegeneracy assumptions are often needed in order to prove the local fast convergence of suitable algorithms as well as
in the sensitivity analysis for semidefinite programs. One of the more standard nondegeneracy conditions is the geometric
condition used by Alizadeh et al. (Math. Program. 77:111–128, 1997). On the other hand, Kanzow and Nagel (SIAM J. Optim. 15:654–672, 2005) recently introduced an algebraic condition that was used in order to prove, for the first time, the local quadratic convergence
of a suitable algorithm for the solution of semidefinite programs without using the strict complementarity assumption. The
aim of this paper is to show that these two nondegeneracy conditions are equivalent. 相似文献
999.
A finite element CFD algorithm is developed for Euler and Navier-Stokes aerodynamic applications. For the linear basis, the resultant approximation is at least second-order-accurate in time and space for synergistic use of three procedures: (1) a Taylor weak statement, which provides for derivation of companion conservation law systems with embedded dispersion-error control mechanisms; (2) a stiffly stable second-order-accurate implicit Rosenbrock-Runge-Kutta temporal algorithm; and (3) a matrix tensor product factorization that permits efficient numerical linear algebra handling of the terminal large-matrix statement. Thorough analyses are presented regarding well-posed boundary conditions for inviscid and viscous flow specifications. Numerical solutions are generated and compared for critical evaluation of quasi-one- and two-dimensional Euler and Navier-Stokes benchmark test problems. Of critical importance, essentially non-oscillatory solutions are uniformly attained for a range of supercritical flow situations with shocks. 相似文献
1000.
È. M. Saydamatov 《Siberian Advances in Mathematics》2007,17(3):213-226
In the article we study the questions of well-posedness of general nonlocal boundary value problems for pseudodifferential equations in the Besov-type limit spaces. 相似文献