共查询到20条相似文献,搜索用时 15 毫秒
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Masoud Hajarian 《Computers & Mathematics with Applications》2018,75(11):4151-4178
Analysis and design of linear periodic control systems are closely related to the periodic matrix equations. The conjugate direction (CD) method is a famous iterative algorithm to find the solution to nonsymmetric linear systems . In this work, a new method based on the CD method is proposed for computing the symmetric periodic solutions and of general coupled periodic matrix equations for . The key idea of the scheme is to extend the CD method by means of Kronecker product and vectorization operator. In order to assess the convergence properties of the method, some theoretical results are given. Finally two numerical examples are included to illustrate the efficiency and effectiveness of the method. 相似文献
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This paper aims at providing an alternative approach to study global dynamic properties for a two-species chemotaxis model, with the main novelty being that both populations mutually compete with the other on account of the Lotka–Volterra dynamics. More precisely, we consider the following Neumann initial–boundary value problem in a bounded domain , with smooth boundary, where are positive constants.When and , it is shown that under some explicit largeness assumptions on the logistic growth coefficients and , the corresponding Neumann initial–boundary value problem possesses a unique global bounded solution which moreover approaches a unique positive homogeneous steady state of above system in the large time limit. The respective decay rate of this convergence is shown to be exponential.When and , if is suitable large, for all sufficiently regular nonnegative initial data and with and , the globally bounded solution of above system will stabilize toward as in algebraic. 相似文献
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A well-known lemma of Suslin says that for a commutative ring if is unimodular where is monic and , then there exist such that the ideal generated by equals . This lemma played a central role in the resolution of Serre’s Conjecture. In the case where contains a set of cardinality greater than such that is invertible for each in , we prove that the can simply correspond to the elementary operations , , where . These efficient elementary operations enable us to give new and simple algorithms for reducing unimodular rows with entries in to using elementary operations in the case where is an infinite field. Another feature of this paper is that it shows that the concrete local–global principles can produce competitive complexity bounds. 相似文献
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Fenglong Sun Lishan Liu Yonghong Wu 《Computers & Mathematics with Applications》2018,75(10):3685-3701
In this paper, we study the initial boundary value problem for a class of parabolic or pseudo-parabolic equations: where , with being the principal eigenvalue for on and . By using the potential well method, Levine’s concavity method and some differential inequality techniques, we obtain the finite time blow-up results provided that the initial energy satisfies three conditions: (i) ; (ii) , where is a nonnegative constant; (iii) , where involves the -norm or -norm of the initial data. We also establish the lower and upper bounds for the blow-up time. In particular, we obtain the existence of certain solutions blowing up in finite time with initial data at the Nehari manifold or at arbitrary energy level. 相似文献
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Liangliang Ma 《Computers & Mathematics with Applications》2018,75(1):170-186
The magneto-micropolar fluid flows describe the motion of electrically conducting micropolar fluids in the presence of a magnetic field. The issue of whether the strong solution of magneto-micropolar equations in three-dimensional can exist globally in time with large initial data is still unknown. In this paper, we deal with the Cauchy problem of the three-dimensional magneto-micropolar system with mixed partial dissipation, magnetic diffusion and angular viscosity. More precisely, the global existence of smooth solutions to the three-dimensional incompressible magneto-micropolar fluid equations with mixed partial dissipation, magnetic diffusion and angular viscosity are obtained by energy method under the assumption that -norm of the initial data sufficiently small, namely , where is a sufficiently small positive number. This work follows the techniques in the paper of Cao and Wu (2011). 相似文献
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In this paper, we are concerned with the existence of positive radial solutions of the elliptic system where , is a constant, is a parameter and , is continuous and for all . Under some appropriate conditions on the nonlinearity , we show that the above system possesses at least one positive radial solution for any . The proof of our main results is based upon bifurcation techniques. 相似文献