Results 11 to 20 of about 346,922 (234)

On the Number of Nonnegative Solutions to the Inequality a1 +....ar < n [PDF]

open access: yes, 2010
In this paper, we present a simple and fast method for counting the number of nonnegative integer solutions to the equality a1x1+a2x2+: : :+arxr = n where a1; a2; :::; ar and n are positive integers.
Farzaneh , A.   +3 more
core   +9 more sources

Existence of solutions and convergence results for dynamic initial value problems using lower and upper solutions [PDF]

open access: yesElectronic Journal of Differential Equations, 2009
In this article, we study the existence of solutions to first order non-linear initial value problems within the field of "dynamic equations on time scales". We employ the method of upper and lower solutions and Schauder's fixed point theorem.
Atiya H. Zaidi
doaj   +3 more sources

Existence of solutions for Kirchhoff-type problems via the method of lower and upper solutions [PDF]

open access: yesElectronic Journal of Differential Equations, 2019
This article considers elliptic problems of Kirchhoff-type. We give some new definitions of lower and upper solutions for the problem and establish the method of lower and upper solutions when the upper and lower solutions are well ordered, i.e., the ...
Baoqiang Yan   +2 more
doaj   +3 more sources

Positive Solutions of Sturm-Liouville Boundary Value Problems in Presence of Upper and Lower Solutions

open access: yesInternational Journal of Differential Equations, 2011
We consider a kind of Sturm-Liouville boundary value problems. Using variational techniques combined with the methods of upper-lower solutions, the existence of at least one positive solution is established.
Li Zhang, Xiankai Huang, Weigao Ge
doaj   +2 more sources

3D ultimate limit state analysis using discontinuity layout optimization [PDF]

open access: yes, 2012
The recently developed discontinuity layout optimization (DLO) procedure uses limit analysis theory to directly obtain upper bounds on plane strain collapse loads of bodies and has successfully been applied to geotechnical problems.
Hawksbee, Samuel John
core   +6 more sources

Method of upper and lower solutions for fractional differential equations [PDF]

open access: yesElectronic Journal of Differential Equations, 2012
In this paper, we show the existence and uniqueness of solutions for the boundary-value problems of fractional differential equations, using the upper and lower solutions method and monotone iterative algorithm.
Legang Lin, Xiping Liu, Haiqin Fang
doaj   +2 more sources

Lower semicontinuity of attractors for non-autonomous dynamical systems [PDF]

open access: yes, 2009
This paper is concerned with the lower semicontinuity of attractors for semilinear non-autonomous differential equations in Banach spaces. We require the unperturbed attractor to be given as the union of unstable manifolds of time-dependent hyperbolic
Langa, José A.   +3 more
core   +1 more source

Almost periodic upper and lower solutions [PDF]

open access: yes, 2003
The method of upper and lower solutions is a classical tool in the theory of periodic differential equations of the second order. We show that this method does not have a direct extension to almost periodic equations. To do this we construct equations of
M.E. Tarallo   +3 more
core   +1 more source

Existence of solutions for a class of elastic beam problems with simply supported ends

open access: yes四川大学学报. 自然科学版, 2022
We in this paper study the existence of solutions for a class of elastic beam problems with simply supported ends. The proof of the main results is based on the method of lower and upper solutions and the Elias's inequality.
MA Ya-Wei, MA Ru-Yun
doaj  

Monotone iterative method for two-point fractional boundary value problems

open access: yesAdvances in Difference Equations, 2018
In this work, we deal with two-point Riemann–Liouville fractional boundary value problems. Firstly, we establish a new comparison principle. Then, we show the existence of extremal solutions for the two-point Riemann–Liouville fractional boundary value ...
Bo Tang, Jing Zhao, Zhenhai Liu
doaj   +1 more source

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