Search results for "harmonic"

showing 10 items of 984 documents

Rate of growth of frequently hypercyclic functions

2010

AbstractWe study the rate of growth of entire functions that are frequently hypercyclic for the differentiation operator or the translation operator. Moreover, we prove the existence of frequently hypercyclic harmonic functions for the translation operator and we study the rate of growth of harmonic functions that are frequently hypercyclic for partial differentiation operators.

Translation operatorPure mathematicsOperator (computer programming)Harmonic functionGeneral MathematicsEntire functionMathematical analysisRate of growthMathematicsProceedings of the Edinburgh Mathematical Society
researchProduct

La identificación auditiva de los intervalos armónicos musicales:: una propuesta de innovación didáctica basada en la metodología observacional

2014

En el presente artículo se expone un estudio cuyo objetivo es detectar y analizar las dificultades que presentan los estudiantes al identificar auditivamente los intervalos armónicos musicales usando su estrategia habitual. Para llevar a cabo esta investigación se ha utilizado una metodología observacional. Una muestra intencionada de 29 alumnos (entre 11 y 15 años de edad) de lenguaje musical de primer curso de grado profesional pertenecientes al Conservatorio de Música de Girona accedieron voluntariamente a ser filmados en sesiones individuales durante la realización de un test auditivo formado por intervalos armónicos de 3m, 3M, 6m y 6M. Ante la presentación de cada uno de ellos, y de ac…

UNESCO::CIENCIAS DE LAS ARTES Y LAS LETRASDidácticas aplicadasMusical harmonic intervalsAural skillsIdentificación auditiva de intervalos musicalesMusic teachingIntervalos armónicos musicales:CIENCIAS DE LAS ARTES Y LAS LETRAS [UNESCO]Didáctica musicalAural identification of musical intervalsPsicología y educaciónArteHabilidades auditivas musicalesMúsica
researchProduct

A bounded version of bosonic creation and annihilation operators and their related quasi-coherent states

2007

Coherent states are usually defined as eigenstates of an unbounded operator, the so-called annihilation operator. We propose here possible constructions of {\em quasi-coherent states}, which turn out to be {\em quasi} eigenstate of a \underline{bounded} operator related to an annihilation-like operator. We use this bounded operator to construct a sort of modified harmonic oscillator and we analyze the dynamics of this oscillator from an algebraic point of view.

Unbounded operatorPhysicsOperator (physics)Creation and annihilation operatorsFOS: Physical sciencesStatistical and Nonlinear PhysicsMathematical Physics (math-ph)bosonic operatorBounded operatorBounded functionCoherent statesCoherent statesSettore MAT/07 - Fisica MatematicaEigenvalues and eigenvectorsHarmonic oscillatorMathematical PhysicsMathematical physics
researchProduct

Quasiconformal mappings and F-harmonic measure

1983

Unit sphereQuasiconformal mappingMathematical analysisHarmonic measureMathematics
researchProduct

Solutions to the 1-harmonic flow with values into a hyper-octant of the N-sphere

2013

Abstract We announce existence results for the 1-harmonic flow from a domain of R m into the first hyper-octant of the N -dimensional unit sphere, under homogeneous Neumann boundary conditions. The arguments rely on a notion of “geodesic representative” of a BV-vector field on its jump set.

Unit spheren-sphereGeodesicApplied MathematicsMathematical analysisA domainharmonic flowsOctant (solid geometry)non-convex variational problems1-harmonic flowlower semi-continuity and relaxation; total variation flow; 1-harmonic flow; non-convex variational problems; image processing; geodesic; partial differential equations; harmonic flowsimage processingHomogeneoustotal variation flowNeumann boundary conditionJumppartial differential equationslower semi-continuity and relaxationgeodesicMathematics
researchProduct

THE 1-HARMONIC FLOW WITH VALUES IN A HYPEROCTANT OF THE N-SPHERE

2014

We prove the existence of solutions to the 1-harmonic flow — that is, the formal gradient flow of the total variation of a vector field with respect to the [math] -distance — from a domain of [math] into a hyperoctant of the [math] -dimensional unit sphere, [math] , under homogeneous Neumann boundary conditions. In particular, we characterize the lower-order term appearing in the Euler–Lagrange formulation in terms of the “geodesic representative” of a BV-director field on its jump set. Such characterization relies on a lower semicontinuity argument which leads to a nontrivial and nonconvex minimization problem: to find a shortest path between two points on [math] with respect to a metric w…

Unit spherenonconvex variational problemsriemannian manifolds with boundaryGeodesicn-sphereharmonic flows68U1053C2253C4435K9235K67Neumann boundary conditionpartial differential equations49J45MathematicsNumerical Analysisnonlinear parabolic systems; lower semicontinuity and relaxation; total variation flow; 1-harmonic flow; image processing; harmonic flows; partial differential equations; image processing.; geodesics; riemannian manifolds with boundary; nonconvex variational problemslower semicontinuity and relaxation58E20Applied MathematicsMathematical analysis49Q201-harmonic flowimage processingFlow (mathematics)35K55Metric (mathematics)total variation flowVector fieldnonlinear parabolic systemsBalanced flowAnalysisgeodesics
researchProduct

Rotationally symmetric p -harmonic maps fromD2toS2

2013

We consider rotationally symmetric p-harmonic maps from the unit disk D2⊂R2 to the unit sphere S2⊂R3, subject to Dirichlet boundary conditions and with 1<p<∞. We show that the associated energy functional admits a unique minimizer which is of class C∞ in the interior and C1 up to the boundary. We also show that there exist infinitely many global solutions to the associated Euler–Lagrange equation and we completely characterize them.

Unit spheresymbols.namesakeClass (set theory)Applied MathematicsDirichlet boundary conditionMathematical analysissymbolsHarmonic mapBoundary (topology)Unit diskAnalysisMathematicsEnergy functionalJournal of Differential Equations
researchProduct

Practical Implementation of a Synchronous PWM Strategy for Low Switching Frequency FOC of im Drives with ATSAM3X8E Microcontroller

2021

This paper presents a practical implementation of synchronous PWM modulation algorithm for an induction motor field oriented control powered by a DC/AC inverter and implemented on a low-cost microcontroller, the ATSAM3X8E. In particular, a simple algorithm, capable to calculate automatically an optimized set of frequency modulation indexes will be presented. Hysteresis bands are also introduced in the algorithm in order to avoid multiple changeovers during modulation index transitions. Experimental tests and their results will be shown and discussed, highlighting the benefits of the present algorithm, such as reduction of current harmonic content, reduction of current ripple and, consequent…

Vector controlcurrent rippleComputer sciencesynchronous/asynchronous PWMModulation indexVSISettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciReduction (complexity)harmonicselectric drivesHarmonicElectronic engineeringInverterFrequency modulationPulse-width modulationInduction motor
researchProduct

Analytic UHF-CCSD(T) second derivatives: implementation and application to the calculation of the vibration-rotation interaction constants of NCO and…

1998

An implementation of analytic open-shell UHF-CCSD(T) second derivatives is presented. To demonstrate applicability and test the accuracy of the UHF-CCSD(T) approach for the determination of spectroscopical parameters, vibration-rotation interaction constants were calculated for the ground (12Π) and first electronically excited (12Σ) states of the NCO and NCS radicals. In addition, harmonic vibrational frequencies for both states, the Renner-Teller parameter for the ground state, as well as the 12Π→12Σ excitation energy are reported. While the computed values are in good agreement with reliable experimental information for NCO, most of the data presented for NCS are predictions of quantities…

VibrationRenner–Teller effectChemistryExcited stateHarmonicPhysics::Chemical PhysicsPhysical and Theoretical ChemistryAtomic physicsGround stateRotation (mathematics)ExcitationSecond derivativeTheoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta)
researchProduct

A coupled cluster study of the 1 1A1g and 1 1B2u states of benzene

1998

A theoretical investigation of the equilibrium structures and harmonic frequencies of the 1 1A1g and 1 1B2u states of benzene is presented. The performance of coupled cluster singles (CCS), the recently proposed CC2 model, and coupled cluster singles and doubles (CCSD) is compared. The CC2 ground and excited states frequencies are a significant improvement of the CCS results and are relatively close to the CCSD results. A comparative analysis of the vibrations in the two electronic states of both C6H6 and C6D6 is presented. The reliability of predicted shifts in harmonic frequencies between the two states and isotopic shifts is estimated on the basis of the convergence in the CCS, CC2, and …

Vibrationchemistry.chemical_compoundWork (thermodynamics)Coupled clusterchemistryBasis (linear algebra)Excited stateConvergence (routing)HarmonicGeneral Physics and AstronomyPhysical and Theoretical ChemistryAtomic physicsBenzeneThe Journal of Chemical Physics
researchProduct