Results 31 to 40 of about 5,619,071 (301)
Positive solutions of positive linear systems
Linear Algebra and its Applications, 1985 The Volterra-Lotka equations \(dx_ i/dt=x_ i(b_ i-\Sigma a_{ij}x_ j),\) \(b_ i>0\), \(a_{ii}>0\), \(a_{ij}\geq 0\) correspond to an ecosystem with interspecies and intraspecies competition. A steady state solution \(X^*\) exists if \(b_ i-\Sigma a_{ij}X^*_ j=0\).
openaire +2 more sources
On the positivity of solutions to the Smoluchowski equations [PDF]
Mathematika, 1995 The paper deals with positivity properties of solutions to Smoluchowski's coagulation equations, \[ \dot c_j = {1 \over 2} \sum^{j - 1}_{k = 1} a_{j - k,k} c_{j - k} c_k - c_j \sum^\infty_{k = 1} a_{j,k} c_k, \quad j = 1,2, \dots. \] It is proved that, with positive coefficients \(a_{j,k}\), the set \({\mathcal I} (t) : = \{j : c_j(t) > 0\}\) is ...
openaire +3 more sources
, 2015 In this paper, a generalized model of hematopoiesis with delays and impulses is considered. By employing the contraction mapping principle and a novel type of impulsive delay inequality, we prove the existence of a unique positive almost periodic ...
Anh, Trinh Tuan +2 more
core +1 more source
Dynamical behavior of a harvest single species model on growing habitat
, 2014 This paper is concerned with a reaction-diffusion single species model with harvesting on $n$-dimensional isotropically growing domain. The model on growing domain is derived and the corresponding comparison principle is proved.
Ling, Zhi, Zhang, Lai
core +1 more source
Positive solutions of Schrödinger-Kirchhoff-Poisson system without compact condition
Boundary Value Problems, 2017 Purpose The existence of positive solutions for a class of nonlinear Schrödinger-Kirchhoff-Poisson systems. Methods Variational method. Results Some results on the existence of positive solutions.
Fengxia Liu, Shuli Wang
doaj +1 more source
Positive solutions of integrodifferential equations [PDF]
International Journal of Stochastic Analysis, 1992 Integrodifferential equations of the forms urn:x-wiley:20903332:media:ista345783:ista345783-math-0001 are considered, where K ∈ C([0, ∞), [0, ∞)), p ∈ C([0, ∞), [0, ∞)) and q ∈ C((−∞, ∞), [0, ∞)). Necessary conditions and also sufficient conditions for the existence of positive solutions are established.
openaire +3 more sources
Positive solutions for perturbations of the Robin eigenvalue problem plus an indefinite potential
, 2019 We study perturbations of the eigenvalue problem for the negative Laplacian plus an indefinite and unbounded potential and Robin boundary condition. First we consider the case of a sublinear perturbation and then of a superlinear perturbation.
Papageorgiou, N. S. +2 more
core +2 more sources
Mathematical Modelling and Analysis, 2014 In this article, the existence of multiple positive solutions of boundary-value problems for nonlinear singular fractional order elastic beam equations is established.
Yuji Liu
doaj +1 more source
Two nonnegative solutions for two-dimensional nonlinear wave equations
Cubo, 2022 We study a class of initial value problems for two-dimensional nonlinear wave equations. A new topological approach is applied to prove the existence of at least two nonnegative classical solutions.
Svetlin Georgiev, Mohamed Majdoub
doaj +1 more source
Moving in the Dark: Enlightening the Spatial Population Ecology of European Cave Salamanders
Population Ecology, EarlyView.We assessed individual interactions, movement ecology and activity patterns of a subterranean population of Speleomantes strinatii, applying spatial capture–recapture modeling to a photographic dataset of 104 individuals. ABSTRACT Space use and movement are fundamental aspects of organisms' ecology, mirroring individual fitness, behavior, and life ...
Giacomo Rosa +2 more
wiley +1 more source