2,126 research outputs found

    Growth Conditions for Uniqueness of Smooth Positive Solutions to an Elliptic Model

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    The uniqueness of positive solution to the elliptic model ∆u + u[a + g(u, v)] = 0 in Ω, ∆v + v[a + h(u, v)] = 0 in Ω, u = v = 0 on ∂Ω, were investigated

    Uniqueness of steady state positive solutions to a general elliptic system with Dirichlet boundary conditions

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    The purpose of this paper is to give conditions for the uniqueness of positive solution to a rather general type of elliptic system of the Dirichlet problem on a bounded domain Ω in Rn. Also considered are the effects of perturbations on the coexistence state and uniqueness

    Estimates of Life Span of Solutions of a Cauchy Problem

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    In this paper we get estimates of life span of a Cauchy problem ut(x, t) = ∆ u(x, t) +u(x, t)p, x∈Rn, t \u3e0,u(x,0) =λφ(x), x∈Rn in terms of the positive constant parameterλ whenφ(x)∈Lq is a nonnegative bounded continuous function in Rn but not identically zero, where q is large enough. The technique we used in this paper is the Comparison Principle

    Positive Equilibrium Solutions to General Population Model

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    In this paper, we investigate conditions for the existence of positive solution to the following general elliptic system with various growth conditions: {Δu + u(a + g(u, v)) = 0 Δv + v(d + h(u, v)) = 0 u|∂ω=v|∂ω=0 in ω. Our arguments mainly rely on super-sub solutions, maximum principles, spectrum estimates, and some detailed properties for the solution of logistic equations. © 2013 Academic Publications, Ltd

    Smooth Positive Solutions to an Elliptic Model with C2 Functions

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    Two species of animals are competing or cooperating in the same environment. Under what conditions do they coexist peacefully? Or under what conditions does either one of the two species become extinct, that is, is either one of the two species excluded by the other? We investigate this phenomena in mathematical point of view. In this paper we concentrate on coexistence solutions of the competition or cooperation model This system is the general model for the steady state of a competitive or cooperative interacting system depending on growth conditions for and . The techniques used in this paper are elliptic theory, super-sub solutions, maximum principles, and spectrum estimates. The arguments also rely on some detailed properties of the solution of logistic equations

    Positive Solutions to a General Elliptic System with Smooth Functions

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    The purpose of this research is to give a sufficient condition for the existence and nonexistence of positive solutions to a rather general type of elliptic system of the Dirichlet problem on a bounded domain. This research was supported by the Office of Research and Creative Scholarship. The techniques used include upper-lower solutions, eigenvalues of operators, maximum principles, and spectrum estimates. The arguments also rely on some detailed properties of the solutions of logistic equations. These results yields algebraically computable criteria for the positive coexistence of competing species of animals in many biological models
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