Search results for "Linear function"

showing 10 items of 58 documents

A family of higher-order single layer plate models meeting Cz0-requirements for arbitrary laminates

2019

Abstract In the framework of displacement-based equivalent single layer (ESL) plate theories for laminates, this paper presents a generic and automatic method to extend a basis higher-order shear deformation theory (polynomial, trigonometric, hyperbolic…) to a multilayer C z 0 higher-order shear deformation theory. The key idea is to enhance the description of the cross-sectional warping: the odd high-order C z 1 function of the basis model is replaced by one odd and one even high-order function and including the characteristic zig-zag behaviour by means of piecewise linear functions. In order to account for arbitrary lamination schemes, four such piecewise continuous functions are consider…

PolynomialBasis (linear algebra)Mathematical analysis02 engineering and technologyFunction (mathematics)021001 nanoscience & nanotechnologyStress fieldPiecewise linear function020303 mechanical engineering & transports0203 mechanical engineeringPlate theoryCeramics and CompositesPiecewiseImage warping0210 nano-technologyCivil and Structural EngineeringMathematicsComposite Structures
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Three solutions for parametric problems with nonhomogeneous (a,2)-type differential operators and reaction terms sublinear at zero

2019

Abstract We consider parametric Dirichlet problems driven by the sum of a Laplacian and a nonhomogeneous differential operator ( ( a , 2 ) -type equation) and with a reaction term which exhibits arbitrary polynomial growth and a nonlinear dependence on the parameter. We prove the existence of three distinct nontrivial smooth solutions for small values of the parameter, providing sign information for them: one is positive, one is negative and the third one is nodal.

PolynomialSublinear functionApplied Mathematics010102 general mathematicsMathematical analysisDifferential operator01 natural sciencesDirichlet distribution010101 applied mathematicssymbols.namesakeNonlinear systemSettore MAT/05 - Analisi Matematica(a2)-operator Constant sign solutions Nodal solutions Multiplicity of solutions Nonhomogeneous operatorsymbols0101 mathematicsLaplace operatorAnalysisSign (mathematics)MathematicsParametric statisticsJournal of Mathematical Analysis and Applications
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Perturbed eigenvalue problems for the Robin p-Laplacian plus an indefinite potential

2020

AbstractWe consider a parametric nonlinear Robin problem driven by the negativep-Laplacian plus an indefinite potential. The equation can be thought as a perturbation of the usual eigenvalue problem. We consider the case where the perturbation$$f(z,\cdot )$$f(z,·)is$$(p-1)$$(p-1)-sublinear and then the case where it is$$(p-1)$$(p-1)-superlinear but without satisfying the Ambrosetti–Rabinowitz condition. We establish existence and uniqueness or multiplicity of positive solutions for certain admissible range for the parameter$$\lambda \in {\mathbb {R}}$$λ∈Rwhich we specify exactly in terms of principal eigenvalue of the differential operator.

Pure mathematicsSublinear functionPerturbation (astronomy)Sublinear and superlinear perturbationLambda01 natural sciencesNonlinear Picone’s identitySettore MAT/05 - Analisi MatematicaUniqueness0101 mathematicsMathematical PhysicsEigenvalues and eigenvectorsPositive solutionsMathematicsNonlinear regularityAlgebra and Number TheoryMinimal positive solution010102 general mathematicsDifferential operator010101 applied mathematicsNonlinear systemp-LaplacianIndefinite potentialUniquenessNonlinear maximum principleAnalysis
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Manifestation of Curie-Weiss law for optical phase transition

2001

Considerable slowing down is observed for both the temporal development of the coherent oscillation slightly above the threshold and the refractive index grating decay slightly below the threshold for a semilinear photorefractive oscillator with two counter-propagating pump waves. It is shown that in the vicinity of the threshold the reciprocal characteristic time is a linear function of deviation from the threshold coupling strength. This behaviour is similar to an empirical Curie–Weiss law and points to the analogy of the oscillation threshold to a second-order phase transition.

Quantum opticsPhysicsLinear function (calculus)Phase transitionCurie–Weiss lawPhysics and Astronomy (miscellaneous)Condensed matter physicsOscillationGeneral EngineeringPhysics::OpticsGeneral Physics and AstronomyNonlinear opticsPhotorefractive effectRefractive indexApplied Physics B: Lasers and Optics
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Radon-Nikodym theorem in quasi *-algebras

2013

In this paper some properties of continuous representable linear functionals on a quasi $*$-algebra are investigated. Moreover we give properties of operators acting on a Hilbert algebra, whose role will reveal to be crucial for proving a Radon-Nikodym type theorem for positive linear functionals.

Radon–Nikodym theoremPure mathematicsAlgebra and Number TheorySettore MAT/05 - Analisi MatematicaMathematical analysisRadon–Nikodym theorem for positive linear functionals.MathematicsJournal of Operator Theory
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A comparison of simplex and simulated annealing for optimization of a new rear underrun protective device

2012

In this paper, two optimization approaches to improve the product design process have been analysed. Through the analysis of a case study, concerning the designing of a new High Energy Absorption Rear Underrun Protective Device (HEARUPD), two different optimization approaches (simplex and simulated annealing) have been compared. In the implemented optimization processes, the crash between an economy car and the rear part of a truck has been simulated by dynamic numerical (FEM) analyses. Moreover, authors have proposed the use of a suitable linear function of four variables with the purpose of reducing the multi-objective optimization processes to mono-objective ones. That has been made to s…

State variableEngineeringMathematical optimizationSimplexOptimization problembusiness.industryGeneral EngineeringOptimization Simulated annealing Simplex Numerical crash analysisAdaptive simulated annealingLinear functionFinite element methodComputer Science ApplicationsSimplex algorithmModeling and SimulationSimulated annealingSettore ING-IND/15 - Disegno E Metodi Dell'Ingegneria IndustrialebusinessSoftwareEngineering with Computers
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Noise-enhanced stability of periodically driven metastable states

2000

We study the effect of noise-enhanced stability of periodically driven metastable states in a system described by piecewise linear potential. We find that the growing of the average escape time with the intensity of the noise is depending on the initial condition of the system. We analytically obtain the condition for the noise enhanced stability effect and verify it by numerical simulations.

Statistical Mechanics (cond-mat.stat-mech)FOS: Physical sciencesMechanicsDisordered Systems and Neural Networks (cond-mat.dis-nn)Condensed Matter - Disordered Systems and Neural NetworksStability (probability)Piecewise linear functionControl theoryMetastabilityInitial value problemNoise (radio)Intensity (heat transfer)Condensed Matter - Statistical MechanicsMathematics
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Lyapunov exponent and topological entropy plateaus in piecewise linear maps

2013

We consider a two-parameter family of piecewise linear maps in which the moduli of the two slopes take different values. We provide numerical evidence of the existence of some parameter regions in which the Lyapunov exponent and the topological entropy remain constant. Analytical proof of this phenomenon is also given for certain cases. Surprisingly however, the systems with that property are not conjugate as we prove by using kneading theory.

Statistics and ProbabilityMathematical analysisGeneral Physics and AstronomyStatistical and Nonlinear PhysicsTopological entropyLyapunov exponentTopological entropy in physicsModuliPiecewise linear functionsymbols.namesakeModeling and SimulationsymbolsConstant (mathematics)Mathematical PhysicsMathematicsJournal of Physics A: Mathematical and Theoretical
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Analisis bayesiano de los contrastes de hipotesis parametricos

1985

Classical solutions to parametric hypothesis testing are shown to be particular instances of the Bayesian solution to a decision problem with two alternatives, in which the increase in utility for rejecting a false null is a linear function of the discrepancy between the accepted parametric model and the more likely model under the null.

Statistics and ProbabilityNull (mathematics)Parametric modelStatistics Probability and UncertaintyDecision problemAlgorithmBayesian solutionLinear functionParametric statisticsMathematicsStatistical hypothesis testingTrabajos de Estadistica Y de Investigacion Operativa
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Escape Times in Fluctuating Metastable Potential and Acceleration of Diffusion in Periodic Fluctuating Potentials

2004

The problems of escape from metastable state in randomly flipping potential and of diffusion in fast fluctuating periodic potentials are considered. For the overdamped Brownian particle moving in a piecewise linear dichotomously fluctuating metastable potential we obtain the mean first-passage time (MFPT) as a function of the potential parameters, the noise intensity and the mean rate of switchings of the dichotomous noise. We find noise enhanced stability (NES) phenomenon in the system investigated and the parameter region of the fluctuating potential where the effect can be observed. For the diffusion of the overdamped Brownian particle in a fast fluctuating symmetric periodic potential w…

Statistics and ProbabilityStatistical Mechanics (cond-mat.stat-mech)FOS: Physical sciencesSawtooth waveCondensed Matter PhysicsNoise (electronics)Fluctuating Metastable PotentialPiecewise linear functionClassical mechanicsMetastabilityPiecewiseEffective diffusion coefficientStatistical physicsDiffusion (business)Brownian motionCondensed Matter - Statistical MechanicsMathematics
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