Search results for "bound"

showing 10 items of 2948 documents

Distributed Adaptive Control for Asymptotically Consensus Tracking of Uncertain Nonlinear Systems With Intermittent Actuator Faults and Directed Comm…

2019

In this article, we investigate the output consensus tracking problem for a class of high-order nonlinear systems with unknown parameters, uncertain external disturbances, and intermittent actuator faults. Under the directed topology conditions, a novel distributed adaptive controller is proposed. The common time-varying trajectory is allowed to be totally unknown by part of subsystems. Therefore, the assumption on the linearly parameterized trajectory signal in most literature is no longer needed. To achieve the relaxation, extra distributed parameter estimators are introduced in all subsystems. Besides, to handle the actuator faults occurring at possibly infinite times, a new adaptive com…

Adaptive controlComputer science05 social sciences050301 educationRelaxation (iterative method)Topology (electrical circuits)02 engineering and technologyTopologyComputer Science ApplicationsHuman-Computer InteractionVDP::Teknologi: 500Nonlinear systemControl and Systems EngineeringControl theory0202 electrical engineering electronic engineering information engineeringTrajectoryUniform boundedness020201 artificial intelligence & image processingElectrical and Electronic EngineeringActuator0503 educationSoftwareInformation SystemsIEEE Transactions on Cybernetics
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Stability Analysis of a Linear Parameter Varying Adaptive Output Feedback Control System

2021

Abstract Output feedback control systems often require an adaptive filter for properly shaping the loop transfer function, as certain system plant parameters may be uncertain or varying. This renders the overall closed loop to a linear parameter varying (LPV) system, for which the stability analysis is challenging due to non-trivial dynamics of the adaptation law. This paper develops a stability analysis technique of a feedback controlled oscillatory system. A polytopic overapproximation of the parameter set together with the feasibility of certain LMIs guarantees asymptotic stability of the closed loop. The varying filter parameter is only required to be lower and upper bounded, where the …

Adaptive filterRange (mathematics)Exponential stabilityControl and Systems EngineeringComputer scienceControl theoryControl systemBounded functionFilter (signal processing)Stability (probability)Transfer functionIFAC-PapersOnLine
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Response of membrane-bound ATPase of Micrococcus luteus to heat and ultraviolet light.

1976

It is shown that the properties of ATPase (EC 3.6.1.3) of Micrococcus luteus depend only to some extent on the state of the membrane to which it is attached. Its interaction with the membrane appears to be largely controlled by polar forces. It is shown, however, that the UV-sensitivity of the membrane-bound ATPase is also significantly influenced by the state of membrane lipids.

Adenosine TriphosphatasesRadiationHot TemperatureMembranesbiologyChemistryMembrane boundUltraviolet RaysMembrane lipidsATPaseBiophysicsMicrococcusDose-Response Relationship RadiationPhospholipasebiology.organism_classificationMicrococcusRadiation EffectsMembraneBiochemistryPhospholipasesUltraviolet lightbiology.proteinMicrococcus luteusGeneral Environmental ScienceRadiation and environmental biophysics
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Interventions for improving psychological detachment from work: A meta-analysis.

2021

Psychological detachment from work during off-job time is crucial to sustaining employee health and well-being. However, this can be difficult to achieve, particularly when job stress is high and recovery is most needed. Boosting detachment from work is therefore of interest to many employees and organizations, and over the last decade numerous interventions have been developed and evaluated. The aim of this meta-analysis was to review and statistically synthesize the state of research on interventions designed to improve detachment both at work and outside of it. After a systematic search (covering the period 1998-2020) of the published and unpublished literature, 30 studies with 34 interv…

AdultMaleStress managementWorkRESOURCESSTRESS-MANAGEMENTRECOVERY EXPERIENCESCONSERVATIONSLEEP QUALITYPsychological interventionOccupational Health ServicesContext (language use)PsycINFOHOME INTERFACEOccupational StressFILE-DRAWER PROBLEMsystematic reviewAdaptation PsychologicalMINDFULNESSHumansinterventionsApplied PsychologyOccupational HealthWork-Life BalanceBOUNDARIESPublic Health Environmental and Occupational HealthMiddle AgedModerationmeta-analysisJOB STRESSMeta-analysisWell-beingFemalepsychological detachment from workOccupational stressPsychologyClinical psychologyJournal of occupational health psychology
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Clinical activity after fingolimod cessation: Disease reactivation or rebound?

2018

Background and purpose There is debate as to whether the apparent rebound after fingolimod discontinuation is related to the discontinuation itself or whether it is due to the natural course of highly active multiple sclerosis (MS). Our aim was to survey the prevalence of severe reactivation and rebound after discontinuation of fingolimod in a cohort of Italian patients with MS. Methods Patients with relapsing-remitting MS who were treated with fingolimod for at least 6 months and who stopped treatment for reasons that were unrelated to inefficacy were included in the analysis. Results A total of 100 patients who had discontinued fingolimod were included in the study. Fourteen patients (14%…

AdultMalemedicine.medical_specialtyAdolescentDiseaseCohort StudiesMultiple sclerosisImmunosuppressive AgentYoung Adult03 medical and health sciencesMultiple Sclerosis Relapsing-Remitting0302 clinical medicineRecurrenceInternal medicineHumansMedicine030212 general & internal medicineFingolimod; Multiple sclerosis; Reactivation; Rebound; Neurology; Neurology (clinical)Natural courseReboundFingolimod Hydrochloridebusiness.industryMultiple sclerosisFingolimodmedicine.diseaseReactivationMagnetic Resonance ImagingFingolimodDiscontinuationItalyWithholding TreatmentNeurologymultiple sclerosiCohortFemaleNeurology (clinical)Cohort StudiebusinessImmunosuppressive Agents030217 neurology & neurosurgeryHumanmedicine.drug
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Effects of Clomipramine on Sleep EEG and Nocturnal Penile Tumescence

1988

The effects of the tricyclic antidepressant clomipramine on sleep EEG and nocturnal penile tumescence (NPT) were investigated during a long-term study in a normal male control subject. During 21 consecutive days the subject received first placebo for 3 days, then stepwise increasing dosages of clomipramine for 10 days, and finally placebo after withdrawal for 8 days. Under clomipramine, rapid eye movement (REM) sleep was suppressed markedly; an REM rebound occurred after withdrawal. Awake and stages 1 and 2 increased while slow wave sleep was diminished under clomipramine. Those non-REM parameters returned to baseline values after drug cessation. NPT was reduced simultaneously with REM slee…

AdultMalemedicine.medical_specialtyClomipramineEjaculationSexual BehaviorRapid eye movement sleepPlaceboREM reboundInternal medicinemedicineHumansPharmacology (medical)Slow-wave sleepPenile ErectionElectroencephalographymedicine.diseasePsychiatry and Mental healthEndocrinologyErectile dysfunctionNocturnal penile tumescenceAnesthesiaClomipramineSleepPsychologymedicine.drugJournal of Clinical Psychopharmacology
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Technical note: a comparison of central and peripheral intraocular pressure using rebound tonometry

2007

Purpose: To compare central and peripheral intraocular pressure (IOP) readings obtained with rebound tonometry.Methods: Intraocular pressure was measured on the right eye of 153 patients (65 males, 88 females), aged from 21 to 85 years (mean +/- S.D., 55.5 +/- 15.2 years) with the ICare rebound tonometer at centre, and 2 mm from the limbus (in the nasal and temporal regions along the 0-180O corneal meridian).Results: Intraocular pressure values obtained with the ICare were 14.9 +/- 2.8; 14.1 +/- 2.5 and 14.5 +/- 2.7 mmHg at centre, nasal and temporal corneal locations, respectively. On average, nasal and temporal IOP readings were 0.75 and 0.37 mmHg lower than the central reading (p 0.05, r…

AdultMalemedicine.medical_specialtyIntraocular pressuregenetic structuresSensitivity and SpecificityICare((R))Cornea03 medical and health sciencesTonometry Ocular0302 clinical medicineReference ValuesOphthalmologyCorneamedicineHumansIntraocular PressureAgedAged 80 and overScience & Technologybusiness.industryReproducibility of ResultsTechnical noteREBOUND TONOMETRYMiddle AgedSensory Systemseye diseasesPeripheralOphthalmologymedicine.anatomical_structureMeridian (perimetry visual field)Temporal RegionsReference values030221 ophthalmology & optometryFemalerebound tonometrysense organsICare®corneal structureperipheral tonometrybusiness030217 neurology & neurosurgeryOptometryintraocular pressure
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Numerical approach to problems of gravitational instability of geostructures with advected material boundaries

1998

SUMMARY We present a numerical approach for solving 2-D mantle flow problems where the chemical composition changes abruptly across intermediate boundaries. The method combines a Galerkin-spline technique with a method of integration over regions bounded by advected interfaces to represent discontinuous variations of material parameters. It allows direct approximation of a natural free surface position, instead of a posteriori calculation of topography from the normal stress at the upper free-slip boundary. We formulate a model where a viscous incompressible fluid filling a square box is divided into layers (not necessarily horizontal) by advected boundaries, across which the density and vi…

AdvectionBoundary (topology)Eulerian pathGeophysicsMechanicsClassification of discontinuitiesDiapirPhysics::GeophysicsPhysics::Fluid Dynamicssymbols.namesakeGeophysicsGeochemistry and PetrologyPosition (vector)AsthenosphereFree surfacesymbolsGeologyGeophysical Journal International
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Aerosol Lidar Intercomparison in the Framework of SPALINET—The Spanish Lidar Network: Methodology and Results

2009

Abstract—A group of eight Spanish lidars was formed in order to extend the European Aerosol Research Lidar Network–Advanced Sustainable Observation System (EARLINET-ASOS)project. This study presents intercomparisons at the hardware and software levels. Results of the system intercomparisons are based on range-square-corrected signals in cases where the lidars viewed the same atmospheres. Comparisons were also made for aeros backscatter coefficients at 1064 nm (2 systems) and 532 nm (all systems), and for extinction coefficients at 532 nm (2 systems). In total, three field campaigns were carried out between 2006 and 2007. Comparisons were limited to the highest layer found before the free tr…

AerosolsLidarXarxes de telecomunicacionsTeledetecció:Enginyeria de la telecomunicació::Telemàtica i xarxes d'ordinadors [Àrees temàtiques de la UPC]BackscatterMeteorologyPlanetary boundary layerSignal theory (Telecommunication)Inversion (meteorology)Atmospheric modelGeofísicaAerosolTroposphereSenyal Teoria del (Telecomunicació)Boundary layerNetwork performance (Telecomunication)LidarGeneral Earth and Planetary SciencesEnvironmental scienceElectrical and Electronic Engineering:Enginyeria de la telecomunicació::Processament del senyal::Processament del senyal en les telecomunicacions [Àrees temàtiques de la UPC]Remote sensingIEEE Transactions on Geoscience and Remote Sensing
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On reliability of systems with moving material subjected to fracture and instability

2015

Abstract The reliability of systems with moving cracked elastic and isotropic material is considered. The material is modeled as a moving plate which continually has a crack on the edge. The plate is subjected to homogeneous tension acting in the traveling direction and the tension varies temporally around a constant value, the set tension. The tension and the length of the crack are modeled by an Ornstein–Uhlenbeck process and an exponential Ornstein–Uhlenbeck process, respectively. Failure is regarded as the state at which the plate becomes unstable or fractures (or both) and a lower bound for the reliability of the system is derived. Considering reliability of the system leads to first p…

Aerospace EngineeringBoundary (topology)Ocean EngineeringInstabilityOrnstein–Uhlenbeck processfirst passage timerandom parametersCivil and Structural EngineeringMathematicsta214Tension (physics)business.industryMechanical EngineeringIsotropyStatistical and Nonlinear PhysicsOrnstein–Uhlenbeck processStructural engineeringMechanicsstabilitymoving plateCondensed Matter PhysicsNuclear Energy and EngineeringfractureFracture (geology)First-hitting-time modelConstant (mathematics)businessProbabilistic Engineering Mechanics
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