Search results for "linear"

showing 10 items of 7165 documents

Assessing Causality in normal and impaired short-term cardiovascular regulation via nonlinear prediction methods

2009

We investigated the ability of mutual nonlinear prediction methods to assess causal interactions in short-term cardiovascular variability during normal and impaired conditions. Directional interactions between heart period (RR interval of the ECG) and systolic arterial pressure (SAP) short-term variability series were quantified as the cross-predictability (CP) of one series given the other, and as the predictability improvement (PI) yielded by the inclusion of samples of one series into the prediction of the other series. Nonlinear prediction was performed through global approximation (GA), approximation with locally constant models (LA0) and approximation with locally linear models (LA1) …

Adultmedicine.medical_specialtySupine positionTime FactorsGeneral MathematicsRR intervalGlobal nonlinear predictionGeneral Physics and AstronomyNeurally-mediated syncopeBlood PressureK-nearest neighbours local nonlinear predictionCardiovascular SystemSyncopeCardiovascular Physiological PhenomenaPhysics and Astronomy (all)Engineering (all)Control theoryHeart RateNeurally mediated syncopeInternal medicinemedicinePressureHumansMathematics (all)Computer SimulationOut-of-sample predictionMathematicsModels StatisticalGeneral EngineeringLinear modelModels CardiovascularNonlinear granger causalityModels TheoreticalControl subjectsHeart rate and arterial pressure variabilityCausalityNonlinear predictionTerm (time)Case-Control StudiesSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaCardiologyAlgorithms
researchProduct

A multicenter, double-blind, randomized, placebo-controlled trial of the β3-adrenoceptor agonist solabegron for overactive bladder

2012

Abstract Background β-Adrenoceptor agonists are effective in animal models of bladder dysfunction, and the human bladder primarily expresses the β3 receptor subtype. Objective To evaluate the efficacy and tolerability of the highly selective and potent β3-adrenoceptor agonist solabegron in a clinical proof-of-concept study in incontinent women with overactive bladder (OAB). Design, setting, and participants This was a randomized, double-blind trial in adult women with OAB (one or more 24-h incontinence episodes and eight or more average 24-h micturitions). Interventions Solabegron 50mg ( n =88), solabegron 125mg ( n =85), or placebo ( n =85)—all twice daily—were administered. Outcome measur…

Adultmedicine.medical_specialtyTime FactorsUrologymedia_common.quotation_subjectUrinary BladderArgentinaTaiwanPlacebo-controlled studyUrologyUrinationAdrenergic beta-3 Receptor AgonistsPlaceboBenzoatesUrinationDrug Administration ScheduleSouth AfricaYoung AdultSolabegronDouble-Blind MethodRepublic of KoreamedicineHumansAgedmedia_commonAniline CompoundsUrinary Bladder Overactivebusiness.industryBiphenyl CompoundsAustraliaMiddle Agedmedicine.diseaseEuropeUrodynamicsTreatment OutcomeUrinary IncontinenceBlood pressureOveractive bladderTolerabilityAmbulatoryLinear ModelsFemalebusinessNew Zealandmedicine.drugEuropean urology
researchProduct

Comparison of UV and charged aerosol detection approach in pharmaceutical analysis of statins

2009

Abstract CAD (charged aerosol detector) has recently become a new alternative detection system in HPLC. This detection approach was applied in a new HPLC method for the determination of three of the major statins used in clinical treatment—simvastatin, lovastatin and atorvastatin. The method was optimized and the influence of individual parameters on CAD response and sensitivity was carefully studied. Chromatography was performed on a Zorbax Eclipse XDB C18 (4.6 mm × 75 mm, 3.5 μm), using acetonitrile and formic acid 0.1% as mobile phase. The detection was performed using both CAD (20 pA range) and DAD (diode array detector—238 nm) simultaneously connected in series. In terms of linearity, …

AerosolsSimvastatinAccuracy and precisionChromatographyChemistryFormic acidDetectorAnalytical chemistryLinearityCADHigh-performance liquid chromatographyAnalytical Chemistrychemistry.chemical_compoundEquipment and SuppliesHeptanoic AcidsWide dynamic rangeAtorvastatinPyrrolesLovastatinHydroxymethylglutaryl-CoA Reductase InhibitorsQuantitative analysis (chemistry)Chromatography High Pressure LiquidTabletsTalanta
researchProduct

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
researchProduct

Stochastic analysis of the critical velocity of an axially moving cracked elastic plate

2014

In this study, a probabilistic analysis of the critical velocity for an axially moving cracked elastic and isotropic plate is presented. Axially moving materials are commonly used in modelling of manufacturing processes, like paper making and plastic forming. In such systems, the most serious threats to runnability are instability and material fracture, and finding the critical value of velocity is essential for efficiency. In this paper, a formula for the critical velocity is derived under constraints for the probabilities of instability and fracture. The significance of randomness in different model parameters is investigated for parameter ranges typical of paper material and paper machin…

Aerospace EngineeringOcean EngineeringInstabilityRandomnessCivil and Structural EngineeringPhysicsta113Tension (physics)business.industryMechanical EngineeringplateIsotropypaperiStatistical and Nonlinear PhysicsMechanicsStructural engineeringmoving materialstabilityCondensed Matter PhysicsCritical valueCritical ionization velocityepävarmuusNuclear Energy and EngineeringfractureFracture (geology)businessAxial symmetryProbabilistic engineering mechanics
researchProduct

TAKEOFF AND LANDING ROBUST CONTROL SYSTEM FOR A TANDEM CANARD UAV

2005

In spite of modern wide improvements in UAV’s technologies, a few number of such a vehicles is fully autonomous from takeoff to landing . So, either autonomous operation or operation with minimal human intervention is, actually, the primary design goal for the UAV’s researchers. The core of the problem is the design of the landing and takeoff control system. The objective of this paper is to design a control system in which the same state variables are controlled during both the descending/ascending path and the flare, tacking into account the actual ground effect. Robust control techniques are employed with the aim to cope with atmospheric turbulence, measurement noise, parameter variation…

Aerospace vehicleLandingState variablebusiness.industryComputer scienceAerospace applicationTakeoffLinear-quadratic-Gaussian controlTakeoff and landingTurbulenceNoiseGround effect (aerodynamics)Unmanned vehiclesSettore ING-INF/04 - AutomaticaControl systemTakeoffAerospace engineeringRobust controlbusiness
researchProduct

Aggression towards Referees in Amateur Football in Spain: A Loglinear Approach

2019

Aggressive behavior towards football referees is becoming increasingly common, and as a result we are getting used to it and coming to see it as an inevitable and intrinsic element of football matches. Spectators, players and coaches are all prone to take this view. This article studies how the types of aggression shown by these three groups towards the referee are related to one another, and how they are perceived by the referee, in amateur football. For this purpose, the phenomenon was assessed, using an ad-hoc form, both by an expert and by the referee, in 119 regional and youth football matches in the city of Valencia and surrounding municipalities. We analysed the data using a loglinea…

AggressionPhenomenonPerspective (graphical)medicineLog-linear modelFootballElement (criminal law)medicine.symptomPsychologyAmateurSocial psychologyGeneral PsychologyUniversitas Psychologica
researchProduct

Estimating COVID-19-induced Excess Mortality in Lombardy, Italy.

2022

We compare the expected all-cause mortality with the observed one for different age classes during the pandemic in Lombardy, which was the epicenter of the epidemic in Italy. The first case in Italy was found in Lombardy in early 2020, and the first wave was mainly centered in Lombardy. The other three waves, in Autumn 2020, March 2021 and Summer 2021 are also characterized by a high number of cases in absolute terms. A generalized linear mixed model is introduced to model weekly mortality from 2011 to 2019, taking into account seasonal patterns and year-specific trends. Based on the 2019 year-specific conditional best linear unbiased predictions, a significant excess of mortality is estima…

AgingSurveillanceSARS-CoV-2Short CommunicationCOVID-19Excess mortalityAll-cause mortalitySettore MED/01 - Statistica MedicaItalyAll-cause mortality; COVID-19; Excess mortality; Surveillance; Humans; Italy; Linear Models; Mortality; Pandemics; SARS-CoV-2; COVID-19Linear ModelsHumansGeriatrics and GerontologyMortalitySettore SECS-S/01Settore SECS-S/01 - StatisticaPandemics
researchProduct

Determination of the modulus of elasticity of bone material by an acoustical approach at the forearm distinguishes women with and without vertebral f…

2002

The modulus of elasticity is a parameter characterizing fracture stability of bone independent of bone mineral density. Measurement of acoustical properties of the forearm by determination of the resonant frequency of the ulna in longitudinal direction as a function of sound transmission velocity after adjustment of the measuring result by ulna length yields information about the modulus of elasticity. It was the aim of this study to investigate whether this parameter may distinguish between subjects with and without vertebral fractures independent of bone mineral density. Fifty females (61.1 +/- 9.1 years) were enrolled into the study, 25 with, and 25 age-matched without prevalent osteopor…

Aginganimal structuresMaterials scienceEndocrinology Diabetes and MetabolismOsteoporosisUlnaYoung's modulussymbols.namesakeEndocrinologyForearmBone DensityBone materialLinear regressionInternal MedicinemedicineHumansElasticity (economics)AgedOrthodonticsBone mineralUlnaAcousticsGeneral MedicineAnatomyMiddle Agedmedicine.diseaseElasticityForearmmedicine.anatomical_structuresymbolsOsteoporosisSpinal FracturesFemaleExperimental and Clinical Endocrinology & Diabetes
researchProduct

Seasonal changes in host phenotype manipulation by an acanthocephalan: time to be transmitted?

2009

Parasitology, 136 (2)

Aginghost pigmentationLightZoologySkin PigmentationEnvironmenthost manipulationAcanthocephalaHost-Parasite InteractionsIsopodaAcanthocephala; Asellus aquaticus; host manipulation; host-parasite interaction; host pigmentation; intermediate host; plastic/flexible behaviour; seasonality; trophic transmissionParasite hostingAnimalsAsellus aquaticusAsellus aquaticusAnalysis of VariancebiologyBehavior AnimalseasonalityEcologyHost (biology)intermediate hostIntermediate hostTemperatureAquatic animaltrophic transmissionbiology.organism_classificationhost-parasite interactionCrustaceanSurvival RateInfectious DiseasesPhenotypeLinear ModelsAnimal Science and ZoologyParasitologySeasonsplastic/flexible behaviourAcanthocephalaIsopodaParasitology
researchProduct