Search results for "Regular"

showing 10 items of 855 documents

Multiple solutions with sign information for a (p,2)-equation with combined nonlinearities

2020

We consider a parametric nonlinear Dirichlet problem driven by the sum of a p-Laplacian and of a Laplacian (a (p,2)-equation) and with a reaction which has the competing effects of two distinct nonlinearities. A parametric term which is (p−1)-superlinear (convex term) and a perturbation which is (p−1)-sublinear (concave term). First we show that for all small values of the parameter the problem has at least five nontrivial smooth solutions, all with sign information. Then by strengthening the regularity of the two nonlinearities we produce two more nodal solutions, for a total of seven nontrivial smooth solutions all with sign informations. Our proofs use critical point theory, critical gro…

Settore MAT/05 - Analisi MatematicaConstant sign and nodal solutionFlow invarianceConvex–concave problemStrong comparison principleCritical groupNonlinear regularity
researchProduct

Positive and nodal solutions for nonlinear nonhomogeneous parametric neumann problems

2020

We consider a parametric Neumann problem driven by a nonlinear nonhomogeneous differential operator plus an indefinite potential term. The reaction term is superlinear but does not satisfy the Ambrosetti-Rabinowitz condition. First we prove a bifurcation-type result describing in a precise way the dependence of the set of positive solutions on the parameter λ > 0. We also show the existence of a smallest positive solution. Similar results hold for the negative solutions and in this case we have a biggest negative solution. Finally using the extremal constant sign solutions we produce a smooth nodal solution.

Settore MAT/05 - Analisi MatematicaNonlinear maximum principleStrong comparisonNodal solutionNonlinear nonhomogeneous differential operatorBifurcation-type theoremCritical groupNonlinear regularity theory
researchProduct

Regularity in the Sobolev space $W_{loc}^{1,n}(R^n,R^m)$ and $alpha$-absolute continuity

2008

Settore MAT/05 - Analisi Matematicaregular function.Sobolev Space
researchProduct

A Lebesgue-type decomposition on one side for sesquilinear forms

2021

Sesquilinear forms which are not necessarily positive may have a dierent behavior, with respect to a positive form, on each side. For this reason a Lebesgue-type decomposition on one side is provided for generic forms satisfying a boundedness condition.

Settore MAT/05 - Analisi Matematicasesquilinear forms Lebesgue decomposition regularity singularity complex measures bounded operators
researchProduct

La misurazione della performance accademica: un'analisi applicata al "costo standard per studente in corso"

2017

The recent introduction of the “standard cost per regular student”, as a criterion adopted by the Italian Ministry of Education to measure public university performance, implies a deep afterthought of those methods underlying the design of performance management and measurement systems in Italian universities. This has also to be extended – through a systemic perspective – to the evaluation of the Third Mission activities influencing the corresponding socio-economic context. With the intent to support a diagnostic activity related to the academic performance, this paper aims at introducing a system of output-outcome indicators – within a consistent framework – oriented to measure the driver…

Settore SECS-P/07 - Economia AziendaleProspettiva bilanciata 'output-outcome'Misurazione performance accademicaUniversitàStandard Unit Cost to Educate a Regular StudentOutput-to-Outcome ManagementPerformance IndicatorsCosto standard per studente in corso
researchProduct

High-order regularization in lattice-Boltzmann equations

2017

A lattice-Boltzmann equation (LBE) is the discrete counterpart of a continuous kinetic model. It can be derived using a Hermite polynomial expansion for the velocity distribution function. Since LBEs are characterized by discrete, finite representations of the microscopic velocity space, the expansion must be truncated and the appropriate order of truncation depends on the hydrodynamic problem under investigation. Here we consider a particular truncation where the non-equilibrium distribution is expanded on a par with the equilibrium distribution, except that the diffusive parts of high-order nonequilibrium moments are filtered, i.e., only the corresponding advective parts are retained afte…

Shock waverecurrence relationspolynomialsComputational MechanicsLattice Boltzmann methods114 Physical sciences01 natural sciences010305 fluids & plasmassubspaces0103 physical sciences010306 general physicsFluid Flow and Transfer ProcessesPhysicstensor methods: shock tubesHermite polynomialsRecurrence relationta114AdvectionMechanical EngineeringpolynomitMathematical analysisCondensed Matter PhysicsDistribution functionMechanics of MaterialsRegularization (physics)shock tubes [tensor methods]Shear flowPhysics of Fluids
researchProduct

Random wave run-up with a physically-based Lagrangian shoreline model

2014

Abstract In the present paper the run-up of random waves was calculated by means of a numerical method. In situ measurements based on a video imaging technique have been used for the validation of the present numerical model. The on-site run-up measurements have been carried out at Lido Signorino beach, near Marsala, Italy,along a transect, normal to the shore. A video camera and a linear array of rods have been used to obtain field data. Numerical simulations with a 1DH Boussinesq-type of model for breaking waves which takes into account the wave run-up by means of a Lagrangian shoreline model have been carried out. In such simulations random waves of given spectrum have been propagated in…

ShoreBoussinesq numerical modelgeographygeography.geographical_feature_categoryMeteorologyNumerical analysisBreaking waveVideo cameraGeneral Medicineirregular wave run-upGeodesyirregular wave run-up; Boussinesq numerical model; shorelineRandom waveslaw.inventionSettore ICAR/01 - IdraulicaFlumesymbols.namesakeshorelinelawsymbolsTransectGeologyLagrangianEngineering(all)
researchProduct

Adaptive quadratic regularization for baseline wandering removal in wearable ECG devices

2016

The electrocardiogram (ECG) is one of the most important physiological signals to monitor the health status of a patient. Technological advances allow the size and weight of ECG acquisition devices to be strongly reduced so that wearable systems are now available, even though the computational power and memory capacity is generally limited. An ECG signal is affected by several artifacts, among which the baseline wandering (BW), i.e., a slowly varying variation of its trend, represents a major disturbance. Several algorithms for BW removal have been proposed in the literature. In this paper, we propose new methods to face the problem that require low computational and memory resources and th…

Signal processingmedicine.diagnostic_testComputer scienceReal-time computingWearable computerRegularization (mathematics)030218 nuclear medicine & medical imagingPower (physics)03 medical and health sciences0302 clinical medicineQuadratic equationmedicineBaseline (configuration management)Electrocardiography030217 neurology & neurosurgerySimulation
researchProduct

Homeomorphic graph manifolds: A contribution to the μ constant problem

1999

Abstract We give a characterization, in terms of homological data in covering spaces, of those maps between (3-dimensional) graph manifolds which are homotopic to homeomorphisms. As an application we give a condition on a cobordism between graph manifolds that guarantees that they are homeomorphic. This in turn is applied to give a partial result on the μ -constant problem in (complex) dimension three.

SingularityDimension (graph theory)CobordismBanach manifoldHomology equivalenceCovering spaceμ constant problemMathematics::Algebraic TopologyMathematics::Geometric TopologyDistance-regular graphManifoldCombinatoricsCoxeter graphSeifert fibered spaceMilnor fiberGraph manifoldEdge-transitive graphRicci-flat manifoldComplex algebraic surfaceGeometry and TopologyMathematics::Symplectic Geometry3-manifoldHomeomorphismMathematicsTopology and its Applications
researchProduct

The Effects of Individual Characteristics of the Naval Personnel on Sleepiness and Stress during Two Different Watchkeeping Schedules

2022

Background: Naval service can have a significant impact on the wellbeing of seafarers, and the operation of warships is highly dependent on the personnel on board. Nevertheless, there is a lack of knowledge concerning the impact of seafarers’ individual characteristics on their wellbeing in a naval environment. Therefore, the aim of this study was to investigate individual characteristics of the naval personnel that may be associated with the amount of sleepiness, fatigue and stress responses experienced during shift work and irregular working hours in a naval environment. Methods: The study took place on a Finnish Defence Forces’ Navy missile patrol boat on which 18 crewmembers served as s…

SleepinessväsymysHealth Toxicology and Mutagenesiswatchkeeping3121 Internal medicinesleepinessepätyypillinen työstressvartioveneetWork Schedule ToleranceHumansWakefulnessNaval MedicineFatigueShipsindividual characteristicsirregular working hoursindividual characteristics; individual factors; shift work; watchkeeping; irregular working hours; sleepiness; fatigue; stress; navyPublic Health Environmental and Occupational Healthfysiologiset tekijätstressiindividual factorsHormonesshift worktyön kuormittavuusvuorotyömerivoimatfatiguenavyyksilöllisyysSleepInternational Journal of Environmental Research and Public Health
researchProduct