Results 21 to 30 of about 1,794,477 (278)
We prove some new results on existence of solutions to first--order ordinary differential equations with deviating arguments. Delay differential equations are included in our general framework, which even allows deviations to depend on the unknown ...
Figueroa, Rubén, Pouso, Rodrigo López
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Solving ill-posed bilevel programs [PDF]
This paper deals with ill-posed bilevel programs, i.e., problems admitting multiple lower-level solutions for some upper-level parameters. Many publications have been devoted to the standard optimistic case of this problem, where the difficulty is ...
AG Mersha +43 more
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Existence of bounded trajectories via upper and lower solutions
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MALAGUTI, Luisa, C. Marcelli
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On the nonlocal Fisher-KPP equation: steady states, spreading speed and global bounds
We consider the Fisher-KPP equation with a non-local interaction term. We establish a condition on the interaction that allows for existence of non-constant periodic solutions, and prove uniform upper bounds for the solutions of the Cauchy problem, as ...
Hamel, Francois, Ryzhik, Lenya
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Upper and Lower Solutions and Multiplicity Results
Using the topological degree theory, the author obtains some multiplicity results for the second-order differential equation \(x''=f(t,x,x')\), with both linear (periodic and Neumann) and nonlinear boundary conditions. Here, \(f:[a,b]\times \mathbb{R}^2 \to \mathbb{R}\) is continuous and satisfies certain growth conditions.
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In this article, we are concerned with the periodic solutions of first-order difference equation Δu(t−1)=f(t,u(t))−s,t∈Z,(P)\Delta u\left(t-1)=f\left(t,u\left(t))-s,\hspace{1em}t\in {\mathbb{Z}},\hspace{1.0em}\hspace{1.0em}\left(P) where s∈Rs\in {\mathbb{
Zhao Jiao, Ma Ruyun
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Upper and Lower Solutions and Topological Degree
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Upper and Lower Solutions for a Generalized Emden-Fowler Equation
The paper deals with the problem \(u''+ g(t,u)= 0\), \(u(0)= u(1)= 0\), where the function \(g\) can be singular at \(t=0\), \(t=1\) and \(u=0\). The authors prove the existence of positive solution of this problem, supposing in the main that nonlinearity has to become large enough when \(u\) goes to zero and singularity has to be small enough so that ...
HABETS P., ZANOLIN, Fabio
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Existence of rotating-periodic solutions for nonlinear second order vector differential equations
In this paper, we establish two existence theorems of rotating-periodic solutions for nonlinear second order vector differential equations via the Leray–Schauder degree theory and the lower and upper solutions method.
Jin Zhang, Xue Yang
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Clinical Insights Into Hypercalcemia of Malignancy in Childhood
ABSTRACT Hypercalcemia of malignancy (HCM) is a rare but life‐threatening metabolic emergency in children that occurs in less than 1% of pediatric cancer cases, with a reported incidence ranging from 0.4% to 1.0% across different studies. While it is observed in 10%–20% of adult malignancies, pediatric HCM remains relatively uncommon.
Hüseyin Anıl Korkmaz
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