Results 31 to 40 of about 10,905,906 (292)
Comparison theorems for fourth order differential equations
International Journal of Mathematics and Mathematical Sciences, 1986 This paper establishes an apparently overlooked relationship between the pair of fourth order linear equations yiv−p(x)y=0 and yiv+p(x)y=0, where p is a positive, continuous function defined on [0,∞).
Garret J. Etgen, Willie E. Taylor
doaj +1 more source
Positive solutions of nonlinear fourth-order boundary-value problems with local and non-local boundary conditions [PDF]
, 2008 We establish new existence results for multiple positive solutions of fourth-order nonlinear equations which model deflections of an elastic beam. We consider the widely studied boundary conditions corresponding to clamped and hinged ends and many non ...
J. R. L. Webb +5 more
core +1 more source
Improved Conditions for Oscillation of Functional Nonlinear Differential Equations
Mathematics, 2020 The aim of this work is to study oscillatory properties of a class of fourth-order delay differential equations. New oscillation criteria are obtained by using generalized Riccati transformations.
Omar Bazighifan, Mihai Postolache
doaj +1 more source
A fourth-order compact solver for fractional-in-time fourth-order diffusion equations
CoRR, 2019 A fourth-order compact scheme is proposed for a fourth-order subdiffusion equation with the first Dirichlet boundary conditions. The fourth-order problem is firstly reduced into a couple of spatially second-order system and we use an averaged operator to construct a fourth-order spatial approximation. This averaged operator is compact since it involves
Jialing Zhong +3 more
openaire +2 more sources
On a fourth‐order nonlinear Helmholtz equation
Journal of the London Mathematical Society, 2018 In this paper, we study the mixed dispersion fourth order nonlinear Helmholtz equation $Δ^2 u -βΔu + αu= Γ|u|^{p-2} u$ in $\mathbb R^N$ for positive, bounded and $\mathbb Z^N$-periodic functions $Γ$. Using the dual method of Evequoz and Weth, we find solutions to this equation and establish some of their qualitative properties.
Denis Bonheure +2 more
openaire +7 more sources
New Improved Results for Oscillation of Fourth-Order Neutral Differential Equations
Mathematics, 2021 In this study, a new oscillation criterion for the fourth-order neutral delay differential equation ruxu+puxδu‴α′+quxβϕu=0,u≥u0 is established. By introducing a Riccati substitution, we obtain a new criterion for oscillation without requiring the ...
Osama Moaaz +4 more
doaj +1 more source
A fourth‐order incremental ADC in three‐step
The Journal of Engineering, 2021 This letter presents a second‐order incremental ADC (IADC) operated in three steps, which extends the performance of a second‐order IADC close to that of a fourth‐order IADC with only two amplifiers.
Jia‐Sheng Huang +5 more
doaj +1 more source
Ergodicity and fourth-order spectral moments [PDF]
IEEE Transactions on Information Theory, 1997 Summary: Relationships between ergodicity and structures of fourth-order spectral moments are investigated. In particular, it is shown that second-order ergodicity of a random process is directly related to the distribution of these moments on the normal manifolds of the frequency domain. This result is illustrated by various examples.
openaire +2 more sources
Compact local stencils employed with integrated RBFs for fourth-order differential problems [PDF]
, 2011 In this paper, new compact local stencils based on integrated radial basis functions (IRBFs) for solving fourth-order ordinary differential equations (ODEs) and partial differential equations (PDEs) are presented.
Hoang-Trieu, T.-T. +2 more
core +1 more source
Horizon thermodynamics in fourth-order gravity
Physics Letters B, 2017 In the framework of horizon thermodynamics, the field equations of Einstein gravity and some other second-order gravities can be rewritten as the thermodynamic identity: dE=TdS−PdV.
Meng-Sen Ma
doaj +1 more source