Search results for "Online"

showing 10 items of 4526 documents

Approximation of Feasible Parameter Set in worst case identification of block-oriented nonlinear models

2003

Abstract The estimation of the Feasible Parameter Set for block-oriented nonlinear models in a worst case setting is considered. A bounding procedure is determined both for polytopic and ellipsoidie sets, consisting in the projection of the FPS ⊂ R MN of the extended parameter vector onto suitable M or N-dimensional subspaces and in the solution of convex optimization problems which provide the extreme points of the Parameter Uncertainties Intervals of the model parameteres. Bounds obtained are tighter then in the previous approaches.

Set (abstract data type)Nonlinear systemMathematical optimizationBounding overwatchConvex optimizationApplied mathematicsExtreme pointLinear subspaceProjection (linear algebra)MathematicsBlock (data storage)
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Testing Independence: A New Approach

2000

In time series analysis and modelling, testing for independence allows us to determine if the estimated model is correctly specified. In this work, we present a very simple method to test for serial independence, based on the two-dimensional embedding vectors (the so-called “2-histories”), and we analyse the power and size of such a procedure against a wide set of linear and nonlinear alternatives.

Set (abstract data type)Nonlinear systemSimple (abstract algebra)Independence (mathematical logic)EmbeddingMartingale difference sequenceWhite noiseTime seriesAlgorithmMathematics
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The Kp Hierarchy

1989

As an application of the theory of infinite-dimensional Grassmannians and the representation theory of gl1 we shall study in this chapter certain nonlinear “exactly solvable” systems of differential equations. Exactly solvable means here that the nonlinear system can be transformed to an (infinite-dimensional) linear problem. A prototype of the equations is the Korteweg-de Vries equation $$\frac{{\partial u}}{{\partial t}} = \frac{3}{3}u\frac{{\partial u}}{{\partial x}} + \frac{1}{4}\frac{{{\partial ^3}u}}{{\partial {x^3}}}$$ . It turns out that it is more natural to consider an infinite system of equations like that above, for obtaining explicit solutions. The set of equations is called th…

Set (abstract data type)Pure mathematicsNonlinear systemNonlinear Sciences::Exactly Solvable and Integrable SystemsHierarchy (mathematics)Differential equationGrassmannianKdV hierarchySystem of linear equationsRepresentation theoryMathematics
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IL CRA mette online il Registro Nazionale delle Varietà dei Vitigni

2013

IL CRA mette online il Registro Nazionale delle Varietà dei Vitigni

Settore AGR/09 - Meccanica AgrariaIL CRA mette online il Registro Nazionale delle Varietà dei Vitigni
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Impact of COVID-19 on aquaculture sector in Malaysia: Findings from the first national survey

2021

Abstract Malaysian aquaculture sector consists of 391,000 t of cultivated organisms produced per year with an economic value for over USD 700 million as estimated in 2019. The COVID-19 pandemic caused a large global human pandemic and it is currently ongoing, affecting profoundly Malaysian aquaculture, which is vital for seafood provision and security assurance. Thus, to increase our understanding about how the pandemic affects aquaculture sectors is crucial to design possible management measures both at local and national level. To do it, we designed a survey, starting in May 2020, consisting of 25 online questions to collect information about the impact of COVID-19 on the aquaculture sect…

Settore BIO/07 - EcologiaCoronavirus disease 2019 (COVID-19)Standard operation procedureAquacultureAquatic ScienceAgricultural economicslcsh:Aquaculture. Fisheries. AnglingSupply and demand03 medical and health sciencesAquacultureGoogle formsOrder (exchange)Pandemic030304 developmental biologyInternational levellcsh:SH1-6910303 health sciencesbusiness.industryCOVID-1904 agricultural and veterinary sciencesFood securityAquaculture COVID-19 Food security Google forms Online surveySoftware security assurance040102 fisheries0401 agriculture forestry and fisheriesOnline surveyAnimal Science and ZoologyBusiness
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Josephson-junction-based axion detection through resonant activation

2022

We discuss the resonant activation phenomenon on a Josephson junction due to the coupling of the Josephson system with axions. We show how such an effect can be exploited for axion detection. A nonmonotonic behavior, with a minimum, of the mean switching time from the superconducting to the resistive state versus the ratio of the axion energy and the Josephson plasma energy is found. We demonstrate how variations in switching times make it possible to detect the presence of the axion field. An experimental protocol for observing axions through their coupling with a Josephson system is proposed.

Settore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciCondensed Matter - Mesoscale and Nanoscale PhysicsFieldsPhysics::Instrumentation and DetectorsCondensed Matter - SuperconductivityHigh Energy Physics::PhenomenologyFOS: Physical sciencesStatistical PhysicsNonlinear DynamicsAstrophysicsParticlesResonant activationCondensed MatterCondensed Matter; Materials ; Applied Physics; Statistical PhysicsNonlinear Dynamics; Gravitation; Cosmology ; AstrophysicsParticles ; FieldsCosmologySuperconductivity (cond-mat.supr-con)High Energy Physics::TheoryHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)AxionCondensed Matter::SuperconductivityJosephson junctionMesoscale and Nanoscale Physics (cond-mat.mes-hall)Dark matterMaterialsApplied PhysicsGravitation
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Generation of travelling sine-Gordon breathers in noisy long Josephson junctions

2022

The generation of travelling sine-Gordon breathers is achieved through the nonlinear supratransmission effect in a magnetically driven long Josephson junction, in the presence of losses, a current bias, and a thermal noise source. We demonstrate how to exclusively induce breather modes by means of controlled magnetic pulses. A nonmonotonic behavior of the breather-only generation probability is observed as a function of the noise intensity. An experimental protocol providing evidence of the Josephson breather's existence is proposed.

Settore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciCondensed Matter - Mesoscale and Nanoscale PhysicsGeneral MathematicsApplied MathematicsTravelling sine-Gordon breathersFOS: Physical sciencesGeneral Physics and AstronomyStatistical and Nonlinear PhysicsStochastic fluctuationsNonlinear supratransmissionNonlinear Sciences::Exactly Solvable and Integrable SystemsLong Josephson junctionsCondensed Matter::SuperconductivityMesoscale and Nanoscale Physics (cond-mat.mes-hall)Long Josephson junctions; Nonlinear supratransmission; Stochastic fluctuations; Travelling sine-Gordon breathersNonlinear Sciences::Pattern Formation and Solitons
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An order-adaptive compact approximation Taylor method for systems of conservation laws

2021

Abstract We present a new family of high-order shock-capturing finite difference numerical methods for systems of conservation laws. These methods, called Adaptive Compact Approximation Taylor (ACAT) schemes, use centered ( 2 p + 1 ) -point stencils, where p may take values in { 1 , 2 , … , P } according to a new family of smoothness indicators in the stencils. The methods are based on a combination of a robust first order scheme and the Compact Approximate Taylor (CAT) methods of order 2p-order, p = 1 , 2 , … , P so that they are first order accurate near discontinuities and have order 2p in smooth regions, where ( 2 p + 1 ) is the size of the biggest stencil in which large gradients are n…

Settore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciPhysics and Astronomy (miscellaneous)010103 numerical & computational mathematicsAdaptive high-order methods01 natural sciencesStencilsymbols.namesakeTaylor seriesFOS: MathematicsApplied mathematicsMathematics - Numerical Analysis0101 mathematicsMathematicsConservation lawsFinite differencesNumerical AnalysisConservation lawSmoothnessApplied MathematicsNumerical analysisFinite differenceApproximate Taylor Lax-Wendroff methodsNumerical Analysis (math.NA)Computer Science ApplicationsEuler equations010101 applied mathematicsComputational MathematicsNonlinear systemModeling and Simulationsymbols
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The Emergence of Chaos in Quantum Mechanics

2020

Nonlinearity in Quantum Mechanics may have extrinsic or intrinsic origins and is a liable route to a chaotic behaviour that can be of difficult observations. In this paper, we propose two forms of nonlinear Hamiltonian, which explicitly depend upon the phase of the wave function and produce chaotic behaviour. To speed up the slow manifestation of chaotic effects, a resonant laser field assisting the time evolution of the systems causes cumulative effects that might be revealed, at least in principle. The nonlinear Schr&ouml

Settore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciPhysics and Astronomy (miscellaneous)General MathematicschaosChaotic01 natural sciences010309 opticssymbols.namesakeQuantum mechanics0103 physical sciencesComputer Science (miscellaneous)010306 general physicschaononlinear Schrödinger equationNonlinear Schrödinger equationPoincaré mapPhysicsBloch spherelcsh:MathematicsTime evolutionlcsh:QA1-939Exponential functionhigh order harmonic generationNonlinear systemChemistry (miscellaneous)symbolsHamiltonian (quantum mechanics)Symmetry
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Predator population depending on lemming cycles

2016

In this paper, a Langevin equation for predator population with multiplicative correlated noise is analyzed. The noise source, which is a nonnegative random pulse noise with regulated periodicity, corresponds to the prey population cycling. The increase of periodicity of noise affects the average predator density at the stationary state.

Settore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciPopulationDead-time-distorted Poisson proceDead-time-distorted Poisson process; Langevin equation; Noise in biological systems; population dynamics; Condensed Matter Physics; Statistical and Nonlinear PhysicsCondensed Matter PhysicNoise in biological system01 natural sciences010305 fluids & plasmasLangevin equation0103 physical sciencesQuantitative Biology::Populations and EvolutionStatistical physics010306 general physicseducationPredatorMathematicsPulse noiseeducation.field_of_studyStochastic processMultiplicative functionStatistical and Nonlinear PhysicsCondensed Matter Physicspopulation dynamicLangevin equationNoiseStationary state
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