Search results for "FREQUENCY"

showing 10 items of 2158 documents

Remote heart rate variability for emotional state monitoring

2018

International audience; Several researches have been conducted to recognize emotions using various modalities such as facial expressions , gestures, speech or physiological signals. Among all these modalities, physiological signals are especially interesting because they are mainly controlled by the autonomic nervous system. It has been shown for example that there is an undeniable relationship between emotional state and Heart Rate Variability (HRV). In this paper, we present a methodology to monitor emotional state from physiological signals acquired remotely. The method is based on a remote photoplethysmography (rPPG) algorithm that estimates remote Heart Rate Variability (rHRV) using a …

Facial expressionModalities[ INFO.INFO-TS ] Computer Science [cs]/Signal and Image Processing[INFO.INFO-TS] Computer Science [cs]/Signal and Image ProcessingComputer scienceSpeech recognition020208 electrical & electronic engineering0206 medical engineering[INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV]02 engineering and technology[ INFO.INFO-CV ] Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV]020601 biomedical engineeringSignal[INFO.INFO-CV] Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV][INFO.INFO-TS]Computer Science [cs]/Signal and Image ProcessingFeature (computer vision)Frequency domainPhotoplethysmogram0202 electrical engineering electronic engineering information engineeringHeart rate variabilityGesture
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Coarse scales are sufficient for efficient categorization of emotional facial expressions: Evidence from neural computation

2010

The human perceptual system performs rapid processing within the early visual system: low spatial frequency information is processed rapidly through magnocellular layers, whereas the parvocellular layers process all the spatial frequencies more slowly. The purpose of the present paper is to test the usefulness of low spatial frequency (LSF) information compared to high spatial frequency (HSF) and broad spatial frequency (BSF) visual stimuli in a classification task of emotional facial expressions (EFE) by artificial neural networks. The connectionist modeling results show that an LSF information provided by the frequency domain is sufficient for a distributed neural network to correctly cla…

Facial expressionVisual perceptionArtificial neural networkComputer sciencebusiness.industryCognitive NeurosciencePattern recognitionCognitive neuroscienceComputer Science ApplicationsPerceptual systemModels of neural computationConnectionismArtificial IntelligenceParvocellular cellFrequency domainComputer visionArtificial intelligencebusinessNeurocomputing
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Pulse trains produced by phase-modulation of ultrashort optical pulses: tailoring and characterization

2009

1094-4087; In this paper, creation of pulse doublets and pulse trains by spectral phase modulation of ultrashort optical pulses is investigated. Pulse doublets with specific features are generated through step-like and triangular spectral phase modulation, whereas sequences of pulses with controllable delay and amplitude are produced via sinusoidal phase modulations. A temporal analysis of this type of tailored pulses is exposed and a complete characterization with the SPIDER technique (Spectral Phase Interferometry for Direct Electric-field Reconstruction) is presented. (C) 2004 Optical Society of America.

Femtosecond pulse shapingMaterials scienceFrequency-resolved optical gatingCOHERENT QUANTUM CONTROLFEEDBACKbusiness.industrySpectral phase interferometry for direct electric-field reconstructionFREQUENCY01 natural sciencesPulse shapingAtomic and Molecular Physics and Optics010309 opticsINTERFEROMETRYOpticsMultiphoton intrapulse interference phase scan0103 physical sciencesFEMTOSECOND PULSES010306 general physicsbusiness2-PHOTON TRANSITIONSUltrashort pulsePhase modulationBandwidth-limited pulse
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Formation of ultrashort triangular pulses in optical fibers

2014

Specialty shape ultrashort optical pulses, and triangular pulses in particular, are of great interest in optical signal processing. Compact fiber-based techniques for producing the special pulse waveforms from Gaussian or secant pulses delivered by modern ultrafast lasers are in demand in telecommunications. Using the nonlinear Schr¨odinger equation in an extended form the transformation of ultrashort pulses in a fiber towards triangular shape is characterized by the misfit parameter under variety of incident pulse shapes, energies, and chirps. It is shown that short (1-2 m) conventional single mode fiber can be used for triangular pulse formation in the steady-state regime without any pre-…

Femtosecond pulse shapingMaterials scienceFrequency-resolved optical gatingbusiness.industryLasersSingle-mode optical fiberPhysics::OpticsSignal Processing Computer-AssistedEquipment DesignÒpticaPulse shapingAtomic and Molecular Physics and OpticsOpticsMultiphoton intrapulse interference phase scanChirpTelecommunicationsComputer-Aided DesignFiber Optic TechnologybusinessUltrashort pulseBandwidth-limited pulseOptical Fibers
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Polymorphisms in ABC transporter genes and concentrations of mercury in newborns - Evidence from two Mediterranean birth cohorts

2014

Background: The genetic background may influence methylmercury (MeHg) metabolism and neurotoxicity. ATP binding cassette (ABC) transporters actively transport various xenobiotics across biological membranes. Objective: To investigate the role of ABC polymorphisms as modifiers of prenatal exposure to MeHg. Methods: The study population consisted of participants (n = 1651) in two birth cohorts, one in Italy and Greece (PHIME) and the other in Spain (INMA). Women were recruited during pregnancy in Italy and Spain, and during the perinatal period in Greece. Total mercury concentrations were measured in cord blood samples by atomic absorption spectrometry. Maternal fish intake during pregnancy w…

Fetus -- CreixementMaternal HealthEmbaràsEnvironmental Health and Occupational Healthlcsh:MedicinePhysiologyATP-binding cassette transporterSangToxicologyHeavy MetalsBiochemistryCohort Studieschemistry.chemical_compoundGene FrequencyPregnancySurveys and QuestionnairesGenotypeMedicine and Health SciencesToxinslcsh:ScienceMethylmercuryGeneticsMultidisciplinaryGreeceObstetrics and GynecologyFetal BloodMultidrug Resistance-Associated Protein 23. Good healthChemistryItalyMaternal ExposureResearch DesignCord bloodBlood ChemistryPhysical SciencesPopulation studyFemaleEpigeneticsResearch ArticleAdultNeurotoxicologyPollutantsGenotypeClinical Research DesignToxic AgentsSingle-nucleotide polymorphismBiologyResearch and Analysis MethodsYoung AdultFish ProductsGeneticsmedicineHumansEnvironmental ChemistryAllele frequencyNutritionEvolutionary BiologyPregnancyPolymorphism GeneticPopulation Biologylcsh:RInfant NewbornBiology and Life SciencesComputational BiologyHuman GeneticsMercurymedicine.diseasechemistrySpainGenetic PolymorphismWomen's HealthATP-Binding Cassette Transporterslcsh:QPopulation Genetics
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Effects of Behavioural Finance on Emerging Capital Markets

2014

Abstract A recent common view of finance experts is that it is becoming increasingly difficult to understand how the economy as a whole works. Although the efficient market theory might be considered an ideal model enabling the interpretation of market behavior, it has begun to lose ground, and the rationality hypothesis failed to explain the excessive volatility of the returns and trading volume recorded on both developed capital markets and emerging ones. Adding the behavioral finance perspective to the equation can help us to understand better how market agents will react. In this article, we investigate the factors that may explain the trading volume evolution on two emerging capital ma…

FinanceRational expectationsAlternative trading systemFinancial economicsbusiness.industryGeneral Engineeringbehavioural financeEnergy Engineering and Power TechnologyMarket microstructureBehavioral economicscomputer.software_genreEfficient-market hypothesiscapital marketsrational expectationsEconomicsHigh-frequency tradingAlgorithmic tradingbusinessCapital marketcomputerProcedia Economics and Finance
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The relationship between migration background and knowledge and understanding of personal finance of young adults in Germany

2019

Abstract Financial knowledge and understanding is needed to function well in society; however, young people with a migration background in Germany have been found to perform worse on tests of financial knowledge than those without. Very little investigation has been made into the relationship between financial knowledge and language ability, and ostensibly no in-depth investigation has been made into the connection between frequency of use of the local language and how it correlates to performance on such tests. In this paper we examine the relationship between migration background and knowledge and understanding of personal finance of young adults in Germany. We administered a validated Ge…

Financebusiness.industry030503 health policy & servicesmedia_common.quotation_subject05 social sciencesEconomics educationFrequency of uselanguage.human_languageEducationTest (assessment)German03 medical and health sciences0502 economics and businesslanguageFinancial literacyLocal language050207 economicsYoung adult0305 other medical scienceFunction (engineering)businessPsychologymedia_commonInternational Review of Economics Education
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Generalization of the Den Hartog model and rule-of-thumb formulas for optimal tuned mass dampers

2022

In recent years, the need of improving safety standards for both existing and new buildings against earthquake and wind loads has created a growing interest in the use of the so-called tuned mass dampers, exploited to control, in active or passive way, the dynamic response of structures. To design and optimize tuned mass damper systems, the effective analytical procedure proposed by Den Hartog in his seminal work (Den Hartog, 1985) has been widely adopted over the years, without including damping of the main structure. However, in many cases of engineering interest, the damping of the primary system plays a key role in the overall mechanical response, with the result of an increase in compl…

Fixed pointsOptimal damping ratioAcoustics and UltrasonicsDen Hartog modelOptimal tuning frequency ratioMechanics of MaterialsMechanical EngineeringDamped structureCondensed Matter PhysicsTuned mass damper
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Probabilistic floodplain hazard mapping: managing uncertainty by using a bivariate approach for flood frequency analysis

2014

Floods are a global problem and are considered the most frequent natural disaster world-wide. Many studies show that the severity and frequency of floods have increased in recent years and underline the difficulty to separate the effects of natural climatic changes and human influences as land management practices, urbanization etc. Flood risk analysis and assessment is required to provide information on current or future flood hazard and risks in order to accomplish flood risk mitigation, to propose, evaluate and select measures to reduce it. Both components of risk can be mapped individually and are affected by multiple uncertainties as well as the joint estimate of flood risk. Major sour…

Flood frequency analysis bivariate approachhazard mappingSettore ICAR/02 - Costruzioni Idrauliche E Marittime E Idrologia
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Flood Frequency Analysis for Sicily, Italy

2006

In this paper a regional flood frequency analysis based on the two-component extreme value TCEV distribution is developed using flood data recorded in Sicily. The hierarchical approach, characterized by three investigation levels for estimating the parameters of the theoretical distribution, is discussed first. The highest level of homogeneity hypothesis with regard to the skewness coefficient was verified by using a Monte Carlo technique and taking account of the separation effect proposed by Matalas et al. in 1975. This analysis also showed 1 the inability of the generalized extreme value model to reproduce the empirical cumulative distribution function CDF of the skewness coefficients, a…

Flood mythFlood frequency analysisHomogeneity (statistics)Monte Carlo methodEmpirical distribution functionSkewnessStatisticsGeneralized extreme value distributionEconometricsEnvironmental ChemistryExtreme value theoryGeneral Environmental ScienceWater Science and TechnologyCivil and Structural EngineeringMathematicsJournal of Hydrologic Engineering
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