Search results for "Linear"

showing 10 items of 7165 documents

Incremental dynamic based fragility assessment of reinforced concrete structures: Stationary vs. non-stationary artificial ground motions

2017

Abstract Artificial and natural records are commonly employed by researches and practitioners to perform refined seismic assessments of structures. The techniques for the generation of artificial records and their effectiveness in producing signals which are significantly representative of real earthquakes are still debated as well as results of the consequent seismic assessment to expect from their application. The paper presents an in-depth comparative study highlighting the effect of employing different typologies of artificial ground motion records on seismic assessment results, especially addressing seismic fragility curves. Three sets of 50 stationary, nonstationary evenly modulated a…

EngineeringPeak ground accelerationIncremental dynamic analysi0211 other engineering and technologiesSoil Science020101 civil engineering02 engineering and technologyIncremental dynamic analysisSpectral accelerationIncremental Dynamic Analysis0201 civil engineeringFragilitySeismic assessmentReinforced concrete structuresNonlinear dynamic analysiNon-stationary random processeNonlinear dynamic analysisCivil and Structural EngineeringReinforced concrete structureFragility curves021110 strategic defence & security studiesbusiness.industryArtificial accelerogramsNon-stationary random processesStructural engineeringArtificial accelerograms; Fragility curves; Incremental dynamic analysis; Non-stationary random processes; Nonlinear dynamic analysis; Reinforced concrete structures; Civil and Structural Engineering; Geotechnical Engineering and Engineering Geology; Soil ScienceGeotechnical Engineering and Engineering GeologyReinforced concreteArtificial accelerograms Non-stationary random processes Nonlinear dynamic analysis Incremental dynamic analysis Fragility curves Reinforced concrete structuresNonlinear systemTime historyArtificial accelerogramFragility curvebusiness
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An electromagnetic generator for MAGLEV transportation systems

2015

The fundamental idea of this paper is to use the distribution theory to analyze linear generators in order to include in the mathematical model both ideal a non ideal features. This paper shows how the use of distribution theory can be used in order to establish a mathematical model able to describe both the ordinary working condition of a linear generator for MAGLEV systems as well the role of the unavoidable irregularities and non-ideal features.

EngineeringPower SystemSettore ING-IND/11 - Fisica Tecnica AmbientaleIdeal (set theory)Distribution (number theory)Renewable Energy Sustainability and the Environmentbusiness.industryEnergy Engineering and Power TechnologyControl engineeringElectromagnetic generatorSettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciLinear Synchronous GeneratorElectric MachineWorking conditionLinear congruential generatorMaglevbusiness2015 International Conference on Renewable Energy Research and Applications (ICRERA)
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Concrete softening effects on the axial capacity of RC jacketed circular columns

2016

Abstract Among the different strengthening techniques to repair RC structures, reinforced concrete (RC) jacketing is one of the most commonly adopted, especially for columns. Its wide application is due to its easy application and relatively reduced cost with respect to other methods (e.g. FRP wrapping, Shape Memory Alloy active confinement). The target of RC jacketing is to increase axial, flexural capacity and ductility of weak existing members by means of two main effects: confinement action provided by the jacket and composite action between external jacket and inner concrete. Different theoretical studies have been carried out to calculate the strength enhancement due to confinement ac…

EngineeringRC jacketingbusiness.industryConstitutive equationLinear elasticity0211 other engineering and technologies020101 civil engineering02 engineering and technologyStructural engineeringShape-memory alloyFibre-reinforced plastic0201 civil engineeringRetrofitSofteningSettore ICAR/09 - Tecnica Delle CostruzioniFlexural strength021105 building & constructionUltimate tensile strengthComposite materialbusinessDuctilityPlane stressConfinementCivil and Structural Engineering
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Monte Carlo simulation for the response analysis of long-span suspended cables under wind loads

2004

This paper presents a time-domain approach for analyzing nonlinear random vibrations of long-span suspended cables under transversal wind. A consistent continuous model of the cable, fully accounting for geometrical nonlinearities inherent in cable behavior, is adopted. The effects of spatial correlation are properly included by modeling wind velocity fluctuation as a random function of time and of a single spatial variable ranging over cable span, namely as a one-variate bi-dimensional (1V-2D) random field. Within the context of a Galerkin`s discretization of the equations governing cable motion, a very efficient Monte Carlo-based technique for second-order analysis of the response is prop…

EngineeringRandom fieldDiscretizationSuspended cablebusiness.industrysuspended cable; wind velocity random field; Proper Orthogonal DecompositionMonte Carlo methodRandom functionBuilding and ConstructionMechanicsStructural engineeringAerodynamicsProper orthogonal decompositionWind speedVibrationNonlinear systemModeling and SimulationWind velocityRandom fieldNonlinear vibrationDigital simulationbusinessCivil and Structural EngineeringWind and Structures
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A novel current-based approach for very low variation detection of resistive sensors in wheatstone bridge configuration

2014

EngineeringResistive sensorsWheatstone bridgelaw.inventionlawElectronic engineeringCurrent conveyorHigh resolutionElectrical and Electronic EngineeringLinear responseHigh sensitivityWheatstone bridgeHigh accuracybusiness.industryOffset compensationElectrical engineeringAD844; Bridge balancing; Current conveyor; Current-mode circuit; High accuracy; High resolution; High sensitivity; Linear response; Offset compensation; Resistive sensor detection; Small resistive variation; Wheatstone bridge; Electrical and Electronic EngineeringSmall resistive variationAD844Variation (linguistics)Current-mode circuitKelvin bridgeResistive sensor detectionCurrent (fluid)businessBridge balancing
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Hidden oscillations in aircraft flight control system with input saturation

2013

Abstract The presence of actuator saturation can dramatically degrade the system performance. Since the feedback loop is broken when the actuator saturates the unstable modes of the regulator may then drift to undesirable values. The consequences are that undesired nonlinear oscillations appear and that the settling time may unacceptably increase. Rigorous analysis of nonlinear aircraft models is a very difficult task, that is why a numerical simulation is often used as an analysis and design tool. In this paper difficulties of numerical analysis related to the existence of hidden oscillations in the aircraft control system are demonstrated.

EngineeringSettling timebusiness.industryDescribing functionControl engineeringGeneral MedicineFeedback loopAircraft flight control systemNonlinear systemControl theoryControl systemNonlinear OscillationsbusinessActuatorIFAC Proceedings Volumes
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Corrigendum to “A procedure to calculate the five-parameter model of crystalline silicon photovoltaic modules on the basis of the tabular performance…

2014

Only few manufactures provide the wide set of graphical data that are necessary to use high performance predictive tools for PV systems. On the other hand, reliable graphical data require accurate laboratory measurements that increase manufacturing costs. For this reason PV system designers have to choose between the use of cheap PV modules, lacking in technical data, and the reliable energy predictions that are possible only if the current–voltage characteristics are provided by the PV module manufacturers. This paper describes the procedure to evaluate the parameters of a one-diode equivalent circuit able to accurately epresent the electrical behaviour of a PV panel by means of the minimu…

EngineeringSettore ING-IND/11 - Fisica Tecnica AmbientaleBasis (linear algebra)business.industryMechanical EngineeringPhotovoltaic systemBuilding and ConstructionPhotovoltaic modules Five-parameter model I–V characteristics Solar energyManagement Monitoring Policy and LawEngineering physicsGeneral EnergyElectronic engineeringCrystalline siliconbusinessEnergy (signal processing)Applied Energy
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A procedure to calculate the five-parameter model of crystalline silicon photovoltaic modules on the basis of the tabular performance data

2013

Abstract Only few manufactures provide the wide set of graphical data that are necessary to use high performance predictive tools for PV systems. On the other hand, reliable graphical data require accurate laboratory measurements that increase manufacturing costs. For this reason PV system designers have to choose between the use of cheap PV modules, lacking in technical data, and the reliable energy predictions that are possible only if the current–voltage characteristics are provided by the PV module manufacturers. This paper describes the procedure to evaluate the parameters of a one-diode equivalent circuit able to accurately represent the electrical behaviour of a PV panel by means of …

EngineeringSettore ING-IND/11 - Fisica Tecnica AmbientaleBasis (linear algebra)business.industryMechanical EngineeringReliability (computer networking)Photovoltaic systemBuilding and ConstructionVisual Basic for ApplicationsManagement Monitoring Policy and LawReliability engineeringSet (abstract data type)General EnergyPhotovoltaic modules; Five-parameter model; I–V characteristics; Solar energyEquivalent circuitCrystalline siliconbusinessEnergy (signal processing)Applied Energy
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Type-2 fuzzy control of a fed-batch fermentation reactor

2010

Abstract The aim of the paper is to present the application of type-2 fuzzy logic controllers (T2FLCs) to the control of a fed-batch fermentation reactor in which the penicillin production is carried out. The performance of the control system using T2FLCs is compared by simulation with that of a control system using type-1 fuzzy logic controllers (T1FLCs). The non linear model used for the simulation study is an unstructured model characterized by the presence of non linearities, parameter uncertainty and measurement noise. Simulation results confirm the robustness of the T2FLC which shows a better performance than its type-1 counterpart particularly when uncertainties are present in the co…

EngineeringSettore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciBatch fermentationbusiness.industryNon linear modelControl engineeringFuzzy control systemType (model theory)Fuzzy logicNoiseControl theoryRobustness (computer science)Control systemtype-2 fuzzy logic controller uncertainties non linear system fed batch fermentation reactorbusiness
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Control of the Biodegradation of Mixed Wastes in a Continuous Bioreactor by a Type-2 Fuzzy Logic Controller

2009

Abstract Type-2 fuzzy logic control is proposed for nonlinear processes characterized by bifurcations. A control simulation study was conducted for a bioreactor with cell recycle containing phenol and glucose as carbon and energy sources in which a pure culture of Pseudomonas putida is carried out. The model developed by Ajbar [Ajbar, A. (2001). Stability analysis of the biodegradation of mixed wastes in a continuous bioreactor with cell recycle. Water Research, 35 (5), 1201–1208] was used for the simulations. The particular dynamics of the bioreactor, characterized by two saddle-node bifurcations, makes its control difficult, since it may become unstable also for small variations of some p…

EngineeringSettore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicibusiness.industryGeneral Chemical EngineeringOpen-loop controllerPID controllerControl engineeringFuzzy control systemFuzzy logicComputer Science ApplicationsNonlinear systemBifurcation Bioreactor control Stability Type-2 fuzzy logic controllerControl theoryRobustness (computer science)Energy sourcebusiness
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