Buscar
Mostrando ítems 11-20 de 68
Artículo
Positive solutions for some indefinite nonlinear eigenvalue elliptic problems with Robin boundary conditions
(Elsevier, 2015-02)
We consider a nonlinear eigenvalue problem with indefinite weight under Robin boundary condition. We prove the existence and multiplicity of positive solutions. To this end, we carry out a detailed study of some linear ...
Artículo
Analysis of an age-structured predator-prey model with disease in the prey
(Elsevier, 2006-09)
We study a nonlinear predator-prey model in which the prey population is affected by a mild disease, but has an effect on the death-rate and is assumed to have age structure. We assume that the predator population grows ...
Artículo
Study of the optimal harvesting control and the optimality system for an elliptic problem
(Society for Industrial and Applied Mathematics, 2003)
An optimal harvesting problem with concave non-quadratic cost functional and a diffusive degenerate elliptic logistic state equation type is investigated. Under certain assumptions, we prove the existence and uniqueness ...
Artículo
Existence and uniqueness of positive solution of a logistic equation with nonlinear gradient term
(Cambridge University Press, 2007-06)
The main goal of this work is to study the existence and uniqueness of positive solution of a logistic equation including a nonlinear gradient term. In particular, we use local and global bifurcation together with some ...
Artículo
Stability and uniqueness for cooperative degenerate Lotka-Volterra model
(Elsevier, 2002-06)
In this work we deal with the existence, stability and uniqueness of positive solution of the symbiotic Lotka-Volterra degenerate model. We study and characterize the existence of the principal eigenvalue for weakly coupled ...
Artículo
Existence and uniqueness of positive large solutions to some cooperative elliptic systems
(De Gruyter, 2003-05)
In this work we consider positive solutions to cooperative elliptic systems of the form −∆u = λu−u2 +buv, −∆v = µv −v2 +cuv in a bounded smooth domain Ω ⊂ RN (λ, µ ∈ R, b, c > 0) which blow up on the boundary ∂Ω, that is ...
Artículo
On the long time behavior of non-autonomous Lotka–Volterra models with diffusion via the sub-supertrajectory method
(Elsevier, 2010-07-15)
In this paper we study in detail the geometrical structure of global pullback and forwards attractors associated to non-autonomous Lotka-Volterra systems in all the three cases of competition, symbiosis or prey-predator. ...
Artículo
Nonnegative solutions for a heterogeneous degenerate competition model
(Cambridge University Press, 2004-10)
This paper deals with the existence, uniqueness and qualitative properties of nonnegative and nontrivial solutions of a spatially heterogeneous Lotka-Volterra competition model with nonlinear diffusion. We give conditions ...
Artículo
Optimal control for the degenerate elliptic logistic equation
(Springer, 2002-06)
We consider the optimal control of the harvesting of the diffusive degenerate elliptic logistic equation. Under certain assumptions, we prove the existence and uniqueness of an optimal control. Moreover, the optimality ...
Artículo
Permanence and asymptotically stable complete trajectories for nonautonomous Lotka-Volterra models with diffusion
(Society for Industrial and Applied Mathematics, 2009)
Lotka-Volterra systems are the canonical ecological models used to analyze population dynamics of competition, symbiosis or prey-predator behaviour involving different interacting species in a fixed habitat. Much of the ...