Search results for " Operator"

showing 10 items of 931 documents

Variational differential inclusions without ellipticity condition

2020

The paper sets forth a new type of variational problem without any ellipticity or monotonicity condition. A prototype is a differential inclusion whose driving operator is the competing weighted $(p,q)$-Laplacian $-\Delta_p u+\mu\Delta_q u$ with $\mu\in \mathbb{R}$. Local and nonlocal boundary value problems fitting into this nonstandard setting are examined.

Competing (PQ)-LaplacianApplied Mathematics010102 general mathematicsMathematical analysishemivariational inequalitylocal and nonlocal operatorsq)$-laplacian01 natural sciencesvariational problem010101 applied mathematicsDifferential inclusionSettore MAT/05 - Analisi MatematicaQA1-939lack of ellipticity0101 mathematicsMathematicsMathematicscompeting $(pElectronic Journal of Qualitative Theory of Differential Equations
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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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On the inductive inference of recursive real-valued functions

1999

AbstractWe combine traditional studies of inductive inference and classical continuous mathematics to produce a study of learning real-valued functions. We consider two possible ways to model the learning by example of functions with domain and range the real numbers. The first approach considers functions as represented by computable analytic functions. The second considers arbitrary computable functions of recursive real numbers. In each case we find natural examples of learnable classes of functions and unlearnable classes of functions.

Complex-valued functionGeneral Computer ScienceReal analysisLearning theoryComputable numberInductive inference0102 computer and information sciences02 engineering and technology01 natural sciencesμ-recursive functionComputable analysisTheoretical Computer ScienceAlgebraμ operatorComputable functionReal-valued computationReal-valued function010201 computation theory & mathematics0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processingAlgorithmComputer Science(all)MathematicsTheoretical Computer Science
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Local operators to detect regions of interest

1997

The performance of a visual system is strongly influenced by the information processing that is done in the early vision phase. The need exists to limit the computation on areas of interest to reduce the total amount of data and their redundancy. This paper describes a new method to drive the attention during the analysis of complex scenes. Two new local operators, based on the computation of local moments and symmetries, are combined to drive the selection. Experimental results on real data are also reported. © 1997 Elsevier Science B.V.

ComputationEarly visioncomputer.software_genreMachine learningFacial recognition systemSegmentationArtificial IntelligenceRedundancy (engineering)Selection (linguistics)AttentionSegmentationLimit (mathematics)Face recognitionElectrical and Electronic Engineering1707MathematicsSettore INF/01 - Informaticabusiness.industryInformation processingSignal ProcessingSymmetry operatorComputer Vision and Pattern RecognitionArtificial intelligenceData miningbusinesscomputerSoftwarePattern Recognition Letters
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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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On the Fučík spectrum of the p-Laplacian with no-flux boundary condition

2023

In this paper, we study the quasilinear elliptic problem \begin{align*} \begin{aligned} -\Delta_{p} u&= a\l(u^+\r)^{p-1}-b\l(u^-\r)^{p-1} \quad && \text{in } \Omega,\\ u & = \text{constant} &&\text{on } \partial\Omega,\\ 0&=\int_{\partial \Omega}\left|\nabla u\right|^{p-2}\nabla u\cdot \nu \,\diff \sigma,&& \end{aligned} \end{align*} where the operator is the $p$-Laplacian and the boundary condition is of type no-flux. In particular, we consider the Fu\v{c}\'{\i}k spectrum of the $p$-Laplacian with no-flux boundary condition which is defined as the set $\fucik$ of all pairs $(a,b)\in\R^2$ such that the problem above has a nontrivial solution. It turns out…

Computational MathematicsApplied MathematicsGeneral EngineeringGeneral MedicineEigenvalue problem first nontrivial curve Fucik spectrum no-flux boundary condition p-Laplace differential operatorGeneral Economics Econometrics and FinanceAnalysis
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On the structure of certain ultradistributions

2009

Let "o" be a nonempty open subset of the k-dimensional euclidean space Rk. In this paper we show that, if S is an ultradistribution in "o", belonging to a class of Roumieu type stable under differential operators, then there is a family f , 2 Nk 0, of elements of L1 loc("o") such that S is represented in the formP 2Nk 0 D"a"f "a". Some other results on the structure of certain ultradistributions of Roumieu type are also given.

Computational MathematicsPure mathematicsClass (set theory)Algebra and Number TheoryEuclidean spaceApplied MathematicsMathematical analysisStructure (category theory)Geometry and TopologyType (model theory)Differential operatorAnalysisMathematicsRevista de la Real Academia de Ciencias Exactas, Fisicas y Naturales. Serie A. Matematicas
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Comparison of electron density properties in frozen and relaxed electronic distributions.

2003

Two kinds of electron densities for several small molecules (H(2), FH, CH(3)CH(3), CH(3)NH(2), CH(3)OH, and CH(3)F) have been generated for a wide range of bond distances. The first one, as the sum of the electron density of the isolated fragments, and the second one by optimizing the electron density at each given geometrical disposition. A number of properties of this two electronic distributions have been compared (position of the bond critical points, electron density, Laplacian, curvatures, and local energies). The differences, associated to the bond formation, are found to be very important for most of the cases.

Computational MathematicsRange (particle radiation)Electron densityChemistryPosition (vector)Atoms in moleculesGeneral ChemistryElectronBond formationAtomic physicsLaplace operatorElectron localization functionJournal of computational chemistry
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Equivalence closure in the two-variable guarded fragment

2015

We consider the satisfiability and finite satisfiability problems for the extension of the two-variable guarded fragment in which an equivalence closure operator can be applied to two distinguished binary predicates. We show that the satisfiability and finite satisfiability problems for this logic are 2-ExpTime-complete. This contrasts with an earlier result that the corresponding problems for the full two-variable logic with equivalence closures of two binary predicates are 2-NExpTime-complete.

Computational complexity theoryLogiccomputational complexityguarded fragmentsatisfiability problemBinary numberTheoretical Computer ScienceCombinatoricsArts and Humanities (miscellaneous)Computer Science::Logic in Computer ScienceClosure operatorEquivalence (formal languages)MathematicsDiscrete mathematicssatisfiability problemcomputational complexitydecidabilityequivalence closureSatisfiabilityDecidabilityTheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGESClosure (computer programming)Hardware and ArchitectureTheoryofComputation_LOGICSANDMEANINGSOFPROGRAMSBoolean satisfiability problemSoftwareJournal of Logic and Computation
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Modelling the Effects of Internal Textures on Symmetry Detection Using Fuzzy Operators

2009

Symmetry is a crucial dimension which aids the visual system, human as well as artificial, to organize its environment and to recognize forms and objects. In humans, detection of symmetry, especially bilateral and rotational, is considered to be a primary factor for discovering and interacting with the surrounding environment. Rotational symmetry detecting can be affected by less-known factors, such as the stimulus internal texture. This paper explores how fuzzy operators can be usefully employed in modeling the effects of the internal texture on symmetry detection. To this aim, we selected two symmetry detection algorithms, based on different computational models, and compared their output…

Computational modelVisual perceptionSettore INF/01 - InformaticaComputer sciencebusiness.industryRotational symmetryFuzzy operatorsPattern recognitionFuzzy logicMemetic algorithmComputer visionArtificial intelligencebusinessvisual perception symmetry fuzzy logic
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