Search results for "Solutions"

showing 10 items of 757 documents

An Exact Solution for the Level-Crossing Rate and the Average Duration of Fades of the Envelope of Sum-of-Cisoids Processes

2012

Authors version of an article published in the journal: Procedia Technology. Also available from the publisher at: http://dx.doi.org/10.1016/j.protcy.2012.03.004 Sum-of-cisoids (SOC) processes provide a physically and numerically appealing framework for the modelling and simulation of a wide class of mobile radio channels. This paper is concerned with the problem of finding a general solution for the level-crossing rate (LCR) and the average duration of fades (ADF) of the envelope of SOC processes. Exact expressions are derived for the LCR and the ADF by taking into account that the inphase component, the quadrature component, and the time derivatives of the inphase and quadrature component…

mobile radio channelsVDP::Mathematics and natural science: 400::Information and communication science: 420::Communication and distributed systems: 423Average durationlevel-crossing rateLevel crossingsum-of-cisoidsRayleigh fadingFading distributionExact solutions in general relativityGeographysum-of-sinusoidsVDP::Technology: 500::Information and communication technology: 550::Telecommunication: 552Rice fadingElectronic engineeringaverage duration of fadesGeneral Earth and Planetary SciencesStatistical physicsComputer Science::Information Theoryfading channel simulatorsGeneral Environmental ScienceRayleigh fadingEnvelope (waves)Mobile radio channelProcedia Technology
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Non-homogeneous Dirichlet problems with concave-convex reaction

2022

The variational methods are adopted for establishing the existence of at least two nontrivial solutions for a Dirichlet problem driven by a non-homogeneous differential operator of p-Laplacian type. A large class of nonlinear terms is considered, covering the concave-convex case. In particular, two positive solutions to the problem are obtained under a (p -1)-superlinear growth at infinity, provided that a behaviour less than (p -1)-linear of the nonlinear term in a suitable set is requested.

nonlinear elliptic problemmultiple solutionsVariational methodsp-Laplace operatorSettore MAT/05 - Analisi MatematicaGeneral Mathematicscritical pointRendiconti Lincei - Matematica e Applicazioni
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Solutions with sign information for nonlinear Robin problems with no growth restriction on reaction

2019

We consider a parametric nonlinear Robin problem driven by a nonhomogeneous differential operator. The reaction is a Carathéodory function which is only locally defined (that is, the hypotheses concern only its behaviour near zero). The conditions on the reaction are minimal. Using variational tools together with truncation, perturbation and comparison techniques and critical groups, we show that for all small values of the parameter λ > 0, the problem has at least three nontrivial smooth solutions, two of constant sign and the third nodal.

nonlinear maximum principleApplied Mathematics010102 general mathematicsFunction (mathematics)Differential operator01 natural sciences010101 applied mathematicsNonlinear systemGrowth restrictionSettore MAT/05 - Analisi Matematicaextremal constant sign solutionsApplied mathematicsnodal solutions0101 mathematicscritical groupsAnalysisNonlinear regularity theorySign (mathematics)Parametric statisticsMathematicsApplicable Analysis
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The administration of a single dose collyrium containing hyaluronic acid, amino acids and echinacea purpurea improves the quality-of-life parameters …

2014

ophthalmic solutions Hyaluronic acid open-angle Glaucoma
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C1,α-regularity for variational problems in the Heisenberg group

2017

We study the regularity of minima of scalar variational integrals of $p$-growth, $1<p<\infty$, in the Heisenberg group and prove the H\"older continuity of horizontal gradient of minima.

osittaisdifferentiaaliyhtälötNumerical AnalysisregularityHeisenberg groupsApplied Mathematicsp-Laplacian010102 general mathematicsScalar (mathematics)subelliptic equationsHölder condition01 natural sciences35H20 35J70010101 applied mathematicsMaxima and minimaMathematics - Analysis of PDEsweak solutionsPhysics::Atomic and Molecular Clustersp-LaplacianHeisenberg group0101 mathematicsAnalysisMathematical physicsMathematicsAnalysis &amp; PDE
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On the regularity of very weak solutions for linear elliptic equations in divergence form

2020

AbstractIn this paper we consider a linear elliptic equation in divergence form $$\begin{aligned} \sum _{i,j}D_j(a_{ij}(x)D_i u )=0 \quad \hbox {in } \Omega . \end{aligned}$$ ∑ i , j D j ( a ij ( x ) D i u ) = 0 in Ω . Assuming the coefficients $$a_{ij}$$ a ij in $$W^{1,n}(\Omega )$$ W 1 , n ( Ω ) with a modulus of continuity satisfying a certain Dini-type continuity condition, we prove that any very weak solution $$u\in L^{n'}_\mathrm{loc}(\Omega )$$ u ∈ L loc n ′ ( Ω ) of (0.1) is actually a weak solution in $$W^{1,2}_\mathrm{loc}(\Omega )$$ W loc 1 , 2 ( Ω ) .

osittaisdifferentiaaliyhtälötPure mathematicsvery weak solutionsApplied MathematicsWeak solution010102 general mathematicselliptic equations01 natural sciencesOmegaModulus of continuity010101 applied mathematicsElliptic curve0101 mathematicsDivergence (statistics)AnalysisMathematics
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Asymptotic mean value formulas for parabolic nonlinear equations

2021

In this paper we characterize viscosity solutions to nonlinear parabolic equations (including parabolic Monge–Ampère equations) by asymptotic mean value formulas. Our asymptotic mean value formulas can be interpreted from a probabilistic point of view in terms of dynamic programming principles for certain two-player, zero-sum games. peerReviewed

osittaisdifferentiaaliyhtälötasymptotic mean value formulasparabolic nonlinear equationsMathematics - Analysis of PDEsviscosity solutionsGeneral MathematicsFOS: MathematicsMathematics::Analysis of PDEsparabolic Monge–Ampère equationsAnalysis of PDEs (math.AP)
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On some partial data Calderón type problems with mixed boundary conditions

2021

In this article we consider the simultaneous recovery of bulk and boundary potentials in (degenerate) elliptic equations modelling (degenerate) conducting media with inaccessible boundaries. This connects local and nonlocal Calderón type problems. We prove two main results on these type of problems: On the one hand, we derive simultaneous bulk and boundary Runge approximation results. Building on these, we deduce uniqueness for localized bulk and boundary potentials. On the other hand, we construct a family of CGO solutions associated with the corresponding equations. These allow us to deduce uniqueness results for arbitrary bounded, not necessarily localized bulk and boundary potentials. T…

osittaisdifferentiaaliyhtälötinverse problemsApplied Mathematics(fractional) Calderón problem010102 general mathematicsDegenerate energy levelsMathematical analysisBoundary (topology)Duality (optimization)Type (model theory)partial dataCarleman estimates01 natural sciencesinversio-ongelmatrunge approximationcomplex geometrical optics solutions010101 applied mathematicsBounded functionBoundary value problemUniqueness0101 mathematicsapproksimointiAnalysisMathematicsestimointiJournal of Differential Equations
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On the second-order regularity of solutions to the parabolic p-Laplace equation

2022

AbstractIn this paper, we study the second-order Sobolev regularity of solutions to the parabolic p-Laplace equation. For any p-parabolic function u, we show that $$D(\left| Du\right| ^{\frac{p-2+s}{2}}Du)$$ D ( D u p - 2 + s 2 D u ) exists as a function and belongs to $$L^{2}_{\text {loc}}$$ L loc 2 with $$s&gt;-1$$ s &gt; - 1 and $$1&lt;p&lt;\infty $$ 1 &lt; p &lt; ∞ . The range of s is sharp.

osittaisdifferentiaaliyhtälötp-parabolic functionstime derivativeSobolev regularityMathematics::Analysis of PDEsfundamental inequalityWeak solutionsMathematics (miscellaneous)Fundamental inequalityweak solutionsGRADIENT111 MathematicsTime derivativeEQUIVALENCE
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Asymptotic Mean-Value Formulas for Solutions of General Second-Order Elliptic Equations

2022

Abstract We obtain asymptotic mean-value formulas for solutions of second-order elliptic equations. Our approach is very flexible and allows us to consider several families of operators obtained as an infimum, a supremum, or a combination of both infimum and supremum, of linear operators. The families of equations that we consider include well-known operators such as Pucci, Issacs, and k-Hessian operators.

osittaisdifferentiaaliyhtälötviscosity solutionsMathematics - Analysis of PDEsGeneral MathematicsFOS: MathematicsStatistical and Nonlinear Physicsmean-value formulasIssacs equationk-Hessian equationAnalysis of PDEs (math.AP)
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