Search results for "ANALISI"

showing 10 items of 1536 documents

Nonlinear Nonhomogeneous Robin Problems with Almost Critical and Partially Concave Reaction

2020

We consider a nonlinear Robin problem driven by a nonhomogeneous differential operator, with reaction which exhibits the competition of two Caratheodory terms. One is parametric, $$(p-1)$$-sublinear with a partially concave nonlinearity near zero. The other is $$(p-1)$$-superlinear and has almost critical growth. Exploiting the special geometry of the problem, we prove a bifurcation-type result, describing the changes in the set of positive solutions as the parameter $$\lambda >0$$ varies.

Competition phenomenacompetition phenomenanonlinear maximum principleAlmost critical growthLambda01 natural sciencesSet (abstract data type)symbols.namesakeMathematics - Analysis of PDEsSettore MAT/05 - Analisi Matematica0103 physical sciencesFOS: Mathematics0101 mathematicsbifurcation-type resultMathematicsParametric statisticsNonlinear regularity35J20 35J60010102 general mathematicsMathematical analysisZero (complex analysis)udc:517.956.2Differential operatorBifurcation-type resultalmost critical growthNonlinear systemDifferential geometryFourier analysissymbolsnonlinear regularity010307 mathematical physicsGeometry and TopologyNonlinear maximum principleStrong comparison principlestrong comparison principleAnalysis of PDEs (math.AP)
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A Lebesgue-type decomposition for non-positive sesquilinear forms

2018

A Lebesgue-type decomposition of a (non necessarily non-negative) sesquilinear form with respect to a non-negative one is studied. This decomposition consists of a sum of three parts: two are dominated by an absolutely continuous form and a singular non-negative one, respectively, and the latter is majorized by the product of an absolutely continuous and a singular non-negative forms. The Lebesgue decomposition of a complex measure is given as application.

Complex measurePure mathematicsSesquilinear formType (model theory)Lebesgue integration01 natural sciencesRegularitysymbols.namesakeSettore MAT/05 - Analisi MatematicaLebesgue decomposition0103 physical sciencesDecomposition (computer science)Complex measureFOS: Mathematics0101 mathematicsMathematicsMathematics::Functional AnalysisSingularitySesquilinear formApplied Mathematics010102 general mathematicsAbsolute continuityFunctional Analysis (math.FA)Mathematics - Functional Analysis47A07 15A63 28A12 47A12Product (mathematics)symbols010307 mathematical physicsNumerical range
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VALUTAZIONE DELL'ATTEGGIAMENTO DEI PROPRIETARI DI ANIMALI DA COMPAGNIA NELLA PROCEDURA DI EUTANASIA

2013

Italiano e inglese

Compliance eutanasia analisi associativa e inferenzialeSettore SECS-S/01 - Statistica
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ANALISI NUMERICO-SPERIMENTALE SUL COMPORTAMENTO A FATICA DI COMPOSITI CARALL RIVETTATI

2009

Nel lavoro è descritto un modello di danneggiamento per provini CARALL (CArbon Reinforced ALLuminium), rivettati e non rivettati, sottoposti a prove di fatica mediante flessione pulsatoria a tre punti in controllo di spostamento. I provini sono realizzati sovrapponendo 8 lamine di tessuto intrecciato di carbonio [0°/90°] e resina epossidica con interposta una lamina in lega di alluminio 6061-T6 dello spessore di 0.8mm. Le prove sono state condotte su provini non rivettati (Tipo 1), su provini con due rivetti disposti simmetricamente ad una distanza d=22 mm dalla mezzeria (Tipo 2) e su provini con 2 rivetti disposti ad una distanza d=44 mm dalla mezzeria (Tipo3). L’analisi dei risultati sper…

Compositi rivettati Prove di fatica CARALL Analisi FEM VCCT
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Exploring parallel capabilities of an innovative numerical method for recovering image velocity vectors field

2010

In this paper an efficient method devoted to estimate the velocity vectors field is investigated. The method is based on a quasi-interpolant operator and involves a large amount of computation. The operations characterizing the computational scheme are ideal for parallel processing because they are local, regular and repetitive. Therefore, the spatial parallelism of the process is studied to rapidly proceed in the computation on distributed multiprocessor systems. The process has shown to be synchronous, with good task balancing and requiring a small amount of data transfer.

ComputationNumerical analysisProcess (computing)MultiprocessingField (computer science)Computational scienceComputer Science ApplicationsSettore MAT/08 - Analisi NumericaOperator (computer programming)Parallel processing (DSP implementation)Modeling and SimulationModelling and SimulationImage velocity vectors field Quasi-interpolant operator B-spline functions Distributed multiprocessor systemsAlgorithmMathematicsData transmissionMathematical and Computer Modelling
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Multiple solutions for a discrete boundary value problem involving the p-Laplacian.

2008

Multiple solutions for a discrete boundary value problem involving the p-Laplacian are established. Our approach is based on critical point theory.

Computational MathematicsComputational Theory and MathematicsSettore MAT/05 - Analisi MatematicaModeling and SimulationMathematical analysisFree boundary problemp-LaplacianBoundary value problemMixed boundary conditionElliptic boundary value problemCritical point (mathematics)Discrete boundary value problem multiple solutions p-Laplacian critical points theoryMathematics
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Nonexistence of solutions to higher order evolution inequalities with nonlocal source term on Riemannian manifolds

2022

We establish sufficient conditions for the nonexistence of nontrivial solutions to higher order evolution inequalities, with respect to the time variable. We consider a nonlocal source term, and work on complete noncompact Riemannian manifolds. The obtained conditions depend on the parameters of the problem and the geometry of the manifold. Our main result recovers some nonexistence theorems from the literature, established in the whole Euclidean space.

Computational MathematicsNumerical AnalysisRiemannian manifoldsnontrivial global weak solutionsSettore MAT/05 - Analisi MatematicaApplied Mathematicshigher order evolution inequalitiesNonexistenceAnalysis
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An automatic L1-based regularization method for the analysis of FFC dispersion profiles with quadrupolar peaks

2023

Fast Field-Cycling Nuclear Magnetic Resonance relaxometry is a non-destructive technique to investigate molecular dynamics and structure of systems having a wide range of ap- plications such as environment, biology, and food. Besides a considerable amount of liter- ature about modeling and application of such technique in specific areas, an algorithmic approach to the related parameter identification problem is still lacking. We believe that a robust algorithmic approach will allow a unified treatment of different samples in several application areas. In this paper, we model the parameters identification problem as a con- strained L 1 -regularized non-linear least squares problem. Following…

Computational Mathematicsparameter identificationSettore MAT/08 - Analisi NumericaFast Field Cycling NMR relaxationSettore ING-IND/30 - Idrocarburi E Fluidi Del SottosuoloApplied MathematicsFree-modelSettore AGR/13 - Chimica Agrarianon-linear Gauss-Seidel methodquadrupole relaxation enhancementL 1 regularizationSettore CHIM/06 - Chimica OrganicaSettore CHIM/02 - Chimica Fisica
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Highlighting numerical insights of an efficient SPH method

2018

Abstract In this paper we focus on two sources of enhancement in accuracy and computational demanding in approximating a function and its derivatives by means of the Smoothed Particle Hydrodynamics method. The approximating power of the standard method is perceived to be poor and improvements can be gained making use of the Taylor series expansion of the kernel approximation of the function and its derivatives. The modified formulation is appealing providing more accurate results of the function and its derivatives simultaneously without changing the kernel function adopted in the computation. The request for greater accuracy needs kernel function derivatives with order up to the desidered …

Computer scienceApplied MathematicsGaussianComputation010103 numerical & computational mathematicsFunction (mathematics)01 natural sciences010101 applied mathematicsSmoothed-particle hydrodynamicsComputational Mathematicssymbols.namesakeSettore MAT/08 - Analisi NumericaKernel based methods Smoothed Particle Hydrodynamics Accuracy Convergence Improved fast Gaussian transform.Convergence (routing)symbolsTaylor seriesGaussian function0101 mathematicsFocus (optics)Algorithm
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A Meshfree Solver for the MEG Forward Problem

2015

Noninvasive estimation of brain activity via magnetoencephalography (MEG) involves an inverse problem whose solution requires an accurate and fast forward solver. To this end, we propose the Method of Fundamental Solutions (MFS) as a meshfree alternative to the Boundary Element Method (BEM). The solution of the MEG forward problem is obtained, via the Method of Particular Solutions (MPS), by numerically solving a boundary value problem for the electric scalar potential, derived from the quasi-stationary approximation of Maxwell’s equations. The magnetic field is then computed by the Biot-Savart law. Numerical experiments have been carried out in a realistic single-shell head geometry. The p…

Computer scienceBiomagnetics magnetoencephalography (MEG) method of fundamental solutions (MFS) meshfree methodsScalar potentialInverse problemSolverBoundary knot methodElectronic Optical and Magnetic MaterialsSettore ING-IND/31 - ElettrotecnicaSettore MAT/08 - Analisi NumericaClassical mechanicsApplied mathematicsMethod of fundamental solutionsBoundary value problemElectrical and Electronic EngineeringBoundary element method
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