Search results for "equation"

showing 10 items of 4219 documents

Phase Behavior of Active Swimmers in Depletants: Molecular Dynamics and Integral Equation Theory

2013

We study the structure and phase behavior of a binary mixture where one of the components is self-propelling in nature. The inter-particle interactions in the system were taken from the Asakura-Oosawa model, for colloid-polymer mixtures, for which the phase diagram is known. In the current model version the colloid particles were made active using the Vicsek model for self-propelling particles. The resultant active system was studied by molecular dynamics methods and integral equation theory. Both methods produce results consistent with each other and demonstrate that the Vicsek model based activity facilitates phase separation, thus broadening the coexistence region.

Current (mathematics)PolymersMovementFOS: Physical sciencesGeneral Physics and AstronomyBinary numberCondensed Matter - Soft Condensed MatterMolecular Dynamics SimulationModels BiologicalDiffusionMolecular dynamicsColloidPhase (matter)ColloidsStatistical physicsCondensed Matter - Statistical MechanicsPhase diagramPhysicsStatistical Mechanics (cond-mat.stat-mech)Active systemsModels TheoreticalIntegral equationCondensed Matter::Soft Condensed MatterKineticsClassical mechanicsModels ChemicalSoft Condensed Matter (cond-mat.soft)Physical Review Letters
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Characterization of ellipsoids through an overdetermined boundary value problem of Monge–Ampère type

2014

Abstract The study of the optimal constant in an Hessian-type Sobolev inequality leads to a fully nonlinear boundary value problem, overdetermined with non-standard boundary conditions. We show that all the solutions have ellipsoidal symmetry. In the proof we use the maximum principle applied to a suitable auxiliary function in conjunction with an entropy estimate from affine curvature flow.

Curvature flowApplied MathematicsGeneral MathematicsMathematical analysisFully nonlinear equationsAuxiliary functionEllipsoidSobolev inequalityOverdetermined systemMaximum principlesMaximum principleSettore MAT/05 - Analisi MatematicaAffine curvatureOverdetermined problemsEntropy (information theory)Boundary value problemMathematics
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Analysis of a slow–fast system near a cusp singularity

2016

This paper studies a slow fast system whose principal characteristic is that the slow manifold is given by the critical set of the cusp catastrophe. Our analysis consists of two main parts: first, we recall a formal normal form suitable for systems as the one studied here; afterwards, taking advantage of this normal form, we investigate the transition near the cusp singularity by means of the blow up technique. Our contribution relies heavily in the usage of normal form theory, allowing us to refine previous results. (C) 2015 Elsevier Inc. All rights reserved.

Cusp (singularity)0209 industrial biotechnologyDifferential equationApplied Mathematics010102 general mathematicsMathematical analysis[MATH.MATH-DS]Mathematics [math]/Dynamical Systems [math.DS][ MATH.MATH-DS ] Mathematics [math]/Dynamical Systems [math.DS]02 engineering and technologyDynamical Systems (math.DS)01 natural sciencesPerturbation-theory020901 industrial engineering & automationSlow manifoldNormal form theoryFOS: MathematicsDifferential-equationsPerturbation theory (quantum mechanics)0101 mathematicsMathematics - Dynamical SystemsAnalysisCritical setMathematics
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EFFECTS OF CUSTOMER KNOWLEDGE MANAGEMENT AND CUSTOMER ORIENTATION ON INNOVATION CAPACITY AND MARKETING RESULTS IN SMEs: THE MEDIATING ROLE OF INNOVAT…

2018

Managing customer knowledge is a key of source for SMEs. The principal aim of this paper is to provide empirical evidence on the direct effects of two specific strategic resources: customer orientation and customer knowledge management (CKM), on innovation capacity and marketing results in SMEs. The study also examines the role of innovation orientation as a mediator between customer orientation and CKM. For this purpose, a structural model was proposed and tested through an empirical investigation with variance-based structural equation modeling (PLS) using a sample made up of 210 Spanish SMEs. The findings highlight the relevance of CKM and customer orientation as important strategic res…

Customer knowledgeCustomer knowledge managementStrategy and Management05 social sciencescustomer orientationSample (statistics)Variance (accounting)Orientation (graph theory)Structural equation modelingManagement of Technology and Innovation0502 economics and businessMediation050211 marketingRelevance (information retrieval)innovation orientationBusinessBusiness and International ManagementMarketinginnovation capacityEmpirical evidence050203 business & managementInternational Journal of Innovation Management
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PASSENGER SATISFACTION WITH HYBRID ELECTRIC BUS SERVICE IN NORWAY : A PLS Structural Equation Modelling Approach

2019

Master's thesis Business Administration BE501 - University of Agder 2019 The use of hybrid electric buses (HEBs) in public transit is one of the global attention received topics in this 21st century because of its environment friendly nature. This study focusses on effect of bus service quality dimensions such as bus driver's quality, bus tangible and empathy to determine customer satisfaction level of bus service in Kristiansand region. Structural equation model is used for an empirical investigation to find out the association of perceived bus service quality dimensions with word of mouth mediated by perceived value and customer satisfaction. A total of 276 valid university student respon…

Customer satisfactionWord of mouthStructural equation modellingVDP::Samfunnsvitenskap: 200::Økonomi: 210::Bedriftsøkonomi: 213Hybrid electric busBus tangibleBus serviceBE501EmpathyBus driver’s quality
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Adaptive control of a seven mode truncation of the Kolmogorov flow with drag

2009

Abstract We study a seven dimensional nonlinear dynamical system obtained by a truncation of the Navier–Stokes equations for a two dimensional incompressible fluid with the addition of a linear term modelling the drag friction. We show the bifurcation sequence leading from laminar steady states to chaotic solutions with increasing Reynolds number. Finally, we design an adaptive control which drives the state of the system to the equilibrium point representing the stationary solution.

D'Alembert's paradoxEquilibrium pointTruncationGeneral MathematicsApplied MathematicsMathematical analysisGeneral Physics and AstronomyReynolds numberAdaptive controlStatistical and Nonlinear PhysicsLaminar flowDrag equationFinite dimensional approximationPhysics::Fluid Dynamicssymbols.namesakeClassical mechanicsDragsymbolsBifurcationReynolds-averaged Navier–Stokes equationsMathematics
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High Reynolds number Navier-Stokes solutions and boundary layer separation induced by a rectilinear vortex

2013

Abstract We compute the solutions of Prandtl’s and Navier–Stokes equations for the two dimensional flow induced by a rectilinear vortex interacting with a boundary in the half plane. For this initial datum Prandtl’s equation develops, in a finite time, a separation singularity. We investigate the different stages of unsteady separation for Navier–Stokes solution at different Reynolds numbers Re = 103–105, and we show the presence of a large-scale interaction between the viscous boundary layer and the inviscid outer flow. We also see a subsequent stage, characterized by the presence of a small-scale interaction, which is visible only for moderate-high Re numbers Re = 104–105. We also investi…

D'Alembert's paradoxGeneral Computer SciencePrandtl numberMathematics::Analysis of PDEsFOS: Physical sciencesPhysics::Fluid Dynamicssymbols.namesakeMathematics - Analysis of PDEsHagen–Poiseuille flow from the Navier–Stokes equationsFOS: MathematicsSettore MAT/07 - Fisica MatematicaMathematical PhysicsMathematicsMathematical analysisGeneral EngineeringFluid Dynamics (physics.flu-dyn)Reynolds numberPhysics - Fluid DynamicsMathematical Physics (math-ph)Non-dimensionalization and scaling of the Navier–Stokes equationsBoundary layersymbolsTurbulent Prandtl numberReynolds-averaged Navier–Stokes equationsBoundary layer Unsteady separation Navier Stokes solutions Prandtl’s equation High Reynolds number flows.Analysis of PDEs (math.AP)
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Numerical simulation of fatigue-driven delamination using interface elements

2005

This paper presents a computational technique for the prediction of fatigue-driven delamination growth in composite materials. The interface element, which has been extensively applied to predict delamination growth due to static loading, has been modified to incorporate the effects of cyclic loading. Using a damage mechanics formulation, the constitutive law for the interface element has been extended by incorporating a modified version of a continuum fatigue damage model. The paper presents details of the fatigue degradation strategy and examples of the predicted fatigue delamination growth in mode I, mode II and mixed mode I/II are presented to demonstrate that the numerical model mimics…

DAMAGEinterface elementNumerical AnalysisEngineeringComputer simulationbusiness.industryApplied Mathematicscomposite materialsConstitutive equationGeneral EngineeringFracture mechanicsFatigue damageStructural engineeringdelaminationFinite element methodComputational TechniqueINTERLAMINAR FRACTURE SPECIMENS DAMAGE COMPOSITES FATIGUE GROWTHFATIGUE GROWTHDamage mechanicsMode couplingCOMPOSITESfatigueINTERLAMINAR FRACTURE SPECIMENSbusinessInternational Journal for Numerical Methods in Engineering
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Limits of Sobolev homeomorphisms

2017

Let X; Y subset of R-2 be topologically equivalent bounded Lipschitz domains. We prove that weak and strong limits of homeomorphisms h: X (onto)-> Y in the Sobolev space W-1,W-p (X, R-2), p >= 2; are the same. As an application, we establish the existence of 2D-traction free minimal deformations for fairly general energy integrals. Peer reviewed

DIRICHLET ENERGYGeneral MathematicsDEFORMATIONSMONOTONE MAPPINGSLAPLACE EQUATION01 natural sciencesvariational integralsSobolev inequalityp-harmonic equationNONLINEAR ELASTICITYharmonic mappings111 MathematicsPOINTWISE HARDY INEQUALITIESREGULARITYSPACE0101 mathematicsMathematicsDISTORTIONSURFACESApplied Mathematics010102 general mathematicsMathematical analysisEnergy-minimal deformationsDirichlet's energy010101 applied mathematicsSobolev spaceapproximation of Sobolev homeomorphismsNonlinear elasticityJournal of the European Mathematical Society
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Slow-roll corrections in multi-field inflation: a separate universes approach

2018

In view of cosmological parameters being measured to ever higher precision, theoretical predictions must also be computed to an equally high level of precision. In this work we investigate the impact on such predictions of relaxing some of the simplifying assumptions often used in these computations. In particular, we investigate the importance of slow-roll corrections in the computation of multi-field inflation observables, such as the amplitude of the scalar spectrum $P_\zeta$, its spectral tilt $n_s$, the tensor-to-scalar ratio $r$ and the non-Gaussianity parameter $f_{NL}$. To this end we use the separate universes approach and $\delta N$ formalism, which allows us to consider slow-roll…

DYNAMICSCosmology and Nongalactic Astrophysics (astro-ph.CO)ComputationFOS: Physical sciencesCMB01 natural sciences114 Physical sciences0103 physical sciencesStatistical physicsinflationMULTICOMPONENT INFLATON010303 astronomy & astrophysicsPhysicsSPECTRUMSlow roll010308 nuclear & particles physicsEquations of motionCONSTRAINTSAstronomy and AstrophysicsObservableCOSMOLOGICAL PERTURBATIONSEXPANSION115 Astronomy Space scienceAmplitudeHypersurfacecosmological perturbation theoryCompact formMulti field2ND-ORDERAPPROXIMATIONGENERATIONAstrophysics - Cosmology and Nongalactic Astrophysics
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