Search results for "SIP"

showing 10 items of 1280 documents

Optimal passive-damping design using a decentralized velocity-feedback H-infinity approach

2012

In this work, a new strategy to design passive energy dissipation systems for vibration control of large structures is presented. The method is based on the equivalence between passive damping systems and fully decentralized static velocity-feedback controllers. This equivalence allows to take advantage of recent developments in static output-feedback control design to formulate the passive-damping design as a single optimization problem with Linear Matrix Inequality constraints. To illustrate the application of the proposed methodology, a passive damping system is designed for the seismic protection of a five-story building with excellent results. Peer Reviewed

Work (thermodynamics)EngineeringOptimization problemDecentralized controlStructural Vibration Control:Informàtica::Automàtica i control [Àrees temàtiques de la UPC]Static output-feedbackVibration control:Enginyeria civil::Materials i estructures [Àrees temàtiques de la UPC]Feedback control systemsMatrius (Matemàtica)lcsh:QA75.5-76.95Structural vibration controlControl d'estructures (Enginyeria):93 Systems Theory; Control [Classificació AMS]Control theoryControlMatrix inequalitiesEquivalence (measure theory):93 Systems Theory [Classificació AMS]business.industryOptimal passive dampingLinear matrix inequalityControl engineeringDissipationDecentralised systemComputer Science ApplicationsH-infinity methods in control theoryControl and Systems EngineeringModeling and SimulationSistemes de control per retroacciólcsh:Electronic computers. Computer scienceStructural control (Engineering)businessSoftware
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Free energy and states of fractional-order hereditariness

2014

AbstractComplex materials, often encountered in recent engineering and material sciences applications, show no complete separations between solid and fluid phases. This aspect is reflected in the continuous relaxation time spectra recorded in cyclic load tests. As a consequence the material free energy cannot be defined in a unique manner yielding a significative lack of knowledge of the maximum recoverable work that can extracted from the material. The non-uniqueness of the free energy function is removed in the paper for power-laws relaxation/creep function by using a recently proposed mechanical analogue to fractional-order hereditariness.

Work (thermodynamics)Materials scienceMaterial stateFractional orderMaterial scienceSpectral lineDissipation rateMaterials Science(all)Modelling and SimulationGeneral Materials ScienceComplex materials; Continuous relaxation; Dissipation rates; Fractional derivatives; Fractional order; Free energy function; Material science; Power law creepFree energyPower-law creep/relaxationComplex materialbusiness.industryMechanical EngineeringApplied MathematicsRelaxation (NMR)Order (ring theory)Free energy functionFractional derivativesStructural engineeringFunction (mathematics)MechanicsFractional derivativeCondensed Matter PhysicsFractional calculusContinuous relaxationCreepMechanics of MaterialsModeling and SimulationPower law creepbusinessSettore ICAR/08 - Scienza Delle CostruzioniEnergy (signal processing)International Journal of Solids and Structures
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Collective excitations of 3He clusters

1991

Collective excitations of3He clusters are studied by treating the cluster as a quantum liquid drop. We have used the Random-Phase Approximation sum rules technique within a Density Functional Formalism. Results forL=2 to 10 surface modes and theL=0 volume mode are presented.

[PHYS.NUCL] Physics [physics]/Nuclear Theory [nucl-th]Physicsendocrine system[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th]Liquid drop02 engineering and technology021001 nanoscience & nanotechnology01 natural sciencesMolecular physicsAtomic and Molecular Physics and Optics010305 fluids & plasmasFormalism (philosophy of mathematics)Quantum mechanics0103 physical sciencesCluster (physics)QuasiparticleAtomic physics010306 general physics0210 nano-technologyQuantumhormones hormone substitutes and hormone antagonists
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Vibrating temporal soliton pairs

2007

The study of temporal multisoliton complexes in dissipative systems is of potential interest for the development of new schemes of optical data transport and processing. In the present work, we thus consider pulsations of a soliton pair that consist mainly in the oscillations of the temporal separation and phase relationship between the two pulses, so that the relative motion of the two bound solitons resembles a vibrational motion.

[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics]Physics[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics]3D optical data storageWork (thermodynamics)[ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics]Computer simulation01 natural sciences010309 opticsVibrationDissipative solitonNonlinear Sciences::Exactly Solvable and Integrable SystemsClassical mechanicsMode-locking0103 physical sciencesDissipative systemSoliton010306 general physicsNonlinear Sciences::Pattern Formation and SolitonsComputingMilieux_MISCELLANEOUS
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Dissipative Solitons: present understanding, applications and new developments

2009

Dissipative solitons form a new paradigm for the investigation of phenomena involving stable structures in nonlinear systems far from equilibrium. Basic principles can be applied to a wide range of phenomena in science. Recent results involving solitons and soliton complexes of the complex cubic-quintic Ginzburg–Landau equation are presented.

[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics]Physics[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics][ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics]Applied Mathematics01 natural sciences010309 opticsNonlinear systemDissipative solitonNonlinear Sciences::Exactly Solvable and Integrable SystemsClassical mechanicsModeling and Simulation0103 physical sciencesDissipative systemSolitonAutocatalytic reaction010306 general physicsEngineering (miscellaneous)Nonlinear Sciences::Pattern Formation and SolitonsComputingMilieux_MISCELLANEOUS
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Spatiotemporal optical solitons in nonlinear dissipative media: From stationary light bullets to pulsating complexes

2007

Nonlinear dissipative systems display the full (3+1) D spatiotemporal dynamics of stable optical solitons. We review recent results that were obtained within the complex cubic-quintic Ginzburg-Landau equation model. Numerical simulations reveal the existence of stationary bell-shaped (3+1) D solitons for both anomalous and normal chromatic dispersion regimes, as well as the formation of double soliton complexes. We provide additional insight concerning the possible dynamics of these soliton complexes, consider collision cases between two solitons, and discuss the ways nonstationary evolution can lead to optical pattern formation. © 2007 American Institute of Physics.

[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics]Physics[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics][ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics]Applied MathematicsGeneral Physics and AstronomyPattern formationStatistical and Nonlinear Physics01 natural sciences3. Good health010309 opticsNonlinear systemClassical mechanics0103 physical sciencesDissipative systemGinzburg–Landau theorySoliton010306 general physicsNonlinear Sciences::Pattern Formation and SolitonsMathematical PhysicsComputingMilieux_MISCELLANEOUS
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Vibrating and shaking soliton pairs in dissipative systems

2007

We show that two-soliton solutions in nonlinear dissipative systems can exist in various forms. As with single solitons, they can be stationary, periodic or chaotic. In particular, we find new types of vibrating and shaking soliton pairs. Each type of pair is stable in the sense that the bound state exists in the same form indefinitely. © 2006 Elsevier B.V. All rights reserved.

[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics]Physics[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics][ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics]ChaoticGeneral Physics and AstronomyNonlinear opticsType (model theory)01 natural sciences010309 opticsNonlinear systemDissipative solitonNonlinear Sciences::Exactly Solvable and Integrable SystemsClassical mechanicsQuantum mechanics0103 physical sciencesBound stateDissipative systemSoliton010306 general physicsNonlinear Sciences::Pattern Formation and SolitonsComputingMilieux_MISCELLANEOUSComputer Science::Databases
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Pulsating Dissipative Light Bullets

2009

Finding domains of existence for (3+1)D spatio-temporal dissipative solitons, also called “dissipative light bullets”, by direct numerical solving of a cubic-quintic Ginzburg-Landau equation (CGLE) is a lengthy procedure [1,2]. Variational approaches pave the way for quicker soliton solution mapping, as long as tractable trial functions remain suitable approximations for exact solutions [3,4].

[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics]Physics[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics][ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics]Nonlinear optics01 natural sciences010305 fluids & plasmassymbols.namesakeDissipative solitonClassical mechanics0103 physical sciencessymbolsDissipative systemGinzburg–Landau theorySoliton010306 general physicsDispersion (water waves)Nonlinear Sciences::Pattern Formation and SolitonsGaussian processBifurcationComputingMilieux_MISCELLANEOUS
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Regions of Existence and Transformations of (3+1)-D Dissipative Optical Solitons

2006

We demonstrate the existence of stable optical light bullets in nonlinear dissipative media featuring both normal and anomalous chromatic dispersion. Beyond the domain where stable bullets are found, unstable bullets can be transformed into "rockets".

[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics]Physics[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics][ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics]Optical fiberProjectilePhysics::Medical PhysicsAstrophysics::Cosmology and Extragalactic Astrophysics01 natural scienceslaw.invention010309 opticsPhysics::Popular PhysicsNonlinear systemClassical mechanicslawQuantum mechanicsOptical materials0103 physical sciencesDomain (ring theory)Dissipative system010306 general physicsNonlinear Sciences::Pattern Formation and SolitonsComputingMilieux_MISCELLANEOUS
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Interactions and transformations of dissipative optical bullets

2007

Nonlinear dissipation provides distinctive dynamical properties to optical bullets. According to the system parameters, the dynamical properties of single bullets range from fully stable to pulsating and instable bullets. We are here interested in the following stage, namely the interaction between several optical bullets.

[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics]Physics[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics][ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics]Physics::Medical PhysicsNonlinear opticsAstrophysics::Cosmology and Extragalactic Astrophysics02 engineering and technology021001 nanoscience & nanotechnologyNonlinear dissipation01 natural sciences010309 opticsPhysics::Popular PhysicsClassical mechanics0103 physical sciencesSystem parametersDissipative system0210 nano-technologyNonlinear Sciences::Pattern Formation and SolitonsComputingMilieux_MISCELLANEOUS
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