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181.
《Mathematical Methods in the Applied Sciences》2018,41(1):317-335
This paper is focused on following time‐harmonic Maxwell equation: where is a bounded Lipschitz domain, is the exterior normal, and ω is the frequency. The boundary condition holds when Ω is surrounded by a perfect conductor. Assuming that f is asymptotically linear as , we study the above equation by improving the generalized Nehari manifold method. For an anisotropic material with magnetic permeability tensor and permittivity tensor , ground state solutions are established in this paper. Applying the principle of symmetric criticality, we find 2 types of solutions with cylindrical symmetries in particular for the uniaxial material. 相似文献
182.
Houde Han Zhongyi Huang 《计算数学(英文版)》2008,26(5):728-739
In this paper, we propose a tailored-finite-point method for the numerical simulation of the Helmholtz equation with high wave numbers in heterogeneous medium. Our finite point method has been tailored to some particular properties of the problem, which allows us to obtain approximate solutions with the same behaviors as that of the exact solution very naturally. Especially, when the coefficients are piecewise constant, we can get the exact solution with only one point in each subdomain. Our finite-point method has uniformly convergent rate with respect to wave number k in L^2-norm. 相似文献
183.
State space collapse with application to heavy traffic limits for multiclass queueing networks 总被引:3,自引:0,他引:3
Heavy traffic limits for multiclass queueing networks are a topic of continuing interest. Presently, the class of networks
for which these limits have been rigorously derived is restricted. An important ingredient in such work is the demonstration
of state space collapse. Here, we demonstrate state space collapse for two families of networks, first-in first-out (FIFO)
queueing networks of Kelly type and head-of-the-line proportional processor sharing (HLPPS) queueing networks. We then apply
our techniques to more general networks. To demonstrate state space collapse for FIFO networks of Kelly type and HLPPS networks,
we employ law of large number estimates to show a form of compactness for appropriately scaled solutions. The limits of these
solutions are next shown to satisfy fluid model equations corresponding to the above queueing networks. Results from Bramson
[4,5] on the asymptotic behavior of these limits then imply state space collapse. The desired heavy traffic limits for FIFO
networks of Kelly type and HLPPS networks follow from this and the general criteria set forth in the companion paper Williams
[41]. State space collapse and the ensuing heavy traffic limits also hold for more general queueing networks, provided the
solutions of their fluid model equations converge. Partial results are given for such networks, which include the static priority
disciplines.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
184.
Liu Xiyu 《数学学报(英文版)》1998,14(1):125-134
This paper deals with a class of nonlinear boundary value problems which appears in the study of models of flows through porous
media. Existence results of asymptotic bifurcation and continua are reported both for operator equations and for boundary
value problems.
This work is supported in part by NSF of Shandong Province and NNSF of China 相似文献
185.
Generalized processor sharing has been proposed as a policy for distributing processing in a fair manner between different
data classes in high-speed networks. In this paper we show how recent results on the Skorokhod Problem can be used to construct
and analyze the mapping that takes the input processes into the buffer content. More precisely, we show how to represent the
map in terms of a Skorokhod Problem, and from this infer that the mapping is well defined (existence and uniqueness) and well
behaved (Lipschitz continuity). As an elementary application we present some large deviation estimates for a many data source
model.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
186.
在层流条件下,对饱和多孔介质中的竖直板,研究幂指数型非Newton流的自由对流热交换.非Newton纳米流体服从幂指数型的数学模型,模型综合考虑了Brown运动和热泳的影响.通过相似变换,将问题的偏微分控制方程组,转化为常微分方程组,得到了常微分方程组的数值解.数值解依赖于幂指数n,Lewis数Le,浮力比Nr,Brown运动参数Nb,以及热泳参数Nt.在n和Le的不同取值下,研究并讨论了对相关流体性质参数的影响和简化的Nusselt数. 相似文献
187.
Prediction of the penetrated rust into the microcracks of concrete caused by reinforcement corrosion
Consider a steel-rust-concrete composite consisting of a circular cylindrical concrete cover and a coaxial uniformly corroding steel reinforcement. Prediction of the amount of rust penetrated into the microcracks of concrete cover from a set of data measured at the surface of the concrete is of particular interest. The steel is assumed to be linear isotropic and rust follows a power law stress–strain relation. For the concrete, anisotropic behavior and post-cracking softening model is employed. The formulations lead to a nonlinear boundary value problem which is solved analytically. A key parameter β, defined as the ratio of the volume of corrosion products inside the cracks to the volume of the cracks, is calculated. With some efforts, this parameter is also extracted from the available theoretical and experimental studies for the purpose of comparison. The effects of the mechanical properties of rust and concrete on β is addressed. 相似文献
188.
Alexei Lozinski Olivier Pironneau 《Numerical Methods for Partial Differential Equations》2011,27(1):197-207
We investigate the Schwarz'domain decomposition algorithm for numerical zooms. Error estimates are given for nonmatching meshes for elliptic and parabolic partial differential equations. The method is applied to the security assessment of the burial of nuclear waste which is a typical multiscale problem for porous media flow. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2010 相似文献
189.
In this paper, we study the pulsating fronts of reaction–advection-diffusion equations with two types of nonlinear term in periodic excitable media. Firstly, for the case with combustion nonlinearity, the unique front is proved to decay exponentially when it approaches the unstable limiting state. Secondly, for the degenerate monostable type nonlinearity, it is shown that the front with critical speed is unique, monotone and decays exponentially at negative end, while the fronts of noncritical speeds decay to zero non-exponentially. 相似文献
190.
层状饱和土Biot固结问题状态空间法 总被引:6,自引:1,他引:6
针对饱和多孔介质空间非轴对Biot固结问题,引入状态变量,构造了两组相比独立的状态变量方程,利用Fourier级数和Laplace-Hankel变换,将状态变量方程转换为两组一阶常微分方程组,提出了均质饱和多孔介质空间非轴对称Biot固结问题的传递矩阵,得到以状态变量和传递矩阵乘积的形式表示的均质饱和多孔介质空间非轴对称Biot固结问题的解,利用层间完全接触的条件,可得到N层饱和多孔介质空间非轴对称Biot固结问题的一般解析表达式,文中考虑几种不同的边界条件,分析了两个算例,数值结果表明该方法具有较高的计算精度和良好的计算稳定性。 相似文献