Search results for "correlation"

showing 10 items of 2282 documents

Ab initio calculations of zero-field splitting parameters in linear polyacenes

2003

Abstract The results of ab initio calculations of zero-field splitting (ZFS) parameters are presented for the linear polyacenes from benzene to pentacene. We show how the electron spin–spin (SS) parameters can be efficiently obtained from restricted high-spin open-shell wave functions (ROHF), and present calculations of these, comparing with the results of a recent multi-configurational self-consistent field approach. The SS parameters are obtained from electron SS coupling strengths evaluated as expectation values over the wave functions and from state-to-state spin–orbit (SO) interactions. The results for the two lowest triplet states of naphthalene demonstrate that excellent values can b…

Electronic correlationField (physics)Condensed matter physicsChemistryGeneral Physics and AstronomyZero field splittingMolecular physicsAb initio quantum chemistry methodsSinglet statePhysics::Chemical PhysicsPhysical and Theoretical ChemistryTriplet stateWave functionSpin (physics)Chemical Physics
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Structural and vibrational study of the tautomerism of histamine free-base in solution.

2003

Infrared and Raman spectroscopy in H(2)O and D(2)O and quantum Density Functional calculations were used to determine the structure of histamine free-base in aqueous solution. A quantum mechanical study of the tautomeric equilibrium of histamine free-base in solution was performed at the 6-311G level. Electronic correlation energies were included by using the hybrid functional B3LYP. The solvent was simulated as a continuum characterized by a dielectric constant, and the quantum system (solute) was placed in an ellipsoidal cavity. Solute-solvent electrostatic interaction was calculated by means a multipolar moment expansion introduced in the Hamiltonian. Four relevant histamine conformation…

Electronic correlationMolecular StructureChemistryInfrared spectroscopyGeneral ChemistrySpectrum Analysis RamanBiochemistryMolecular physicsPotential energyCatalysisHybrid functionalSolutionssymbols.namesakeColloid and Surface ChemistryNormal modeComputational chemistryMolecular vibrationSpectroscopy Fourier Transform InfraredsymbolsQuantum TheoryThermodynamicsRaman spectroscopyConformational isomerismHistamineJournal of the American Chemical Society
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Transcriptional changes through menstrual cycle reveal a global transcriptional derepression underlying the molecular mechanism involved in the windo…

2021

The human endometrium is a dynamic tissue that only is receptive to host the embryo during a brief time in the middle secretory phase, called the window of implantation (WOI). Despite its importance, regulation of the menstrual cycle remains incompletely understood. The aim of this study was to characterize the gene cooperation and regulation of menstrual cycle progression, to dissect the molecular complexity underlying acquisition of endometrial receptivity for a successful pregnancy, and to provide the scientific community with detailed gene co-expression information throughout the menstrual cycle on a user-friendly web-tool database. A retrospective gene co-expression analysis was perfor…

Embryologysystems biology of the menstrual cycleTranscription Geneticendometrial receptivitymedia_common.quotation_subjectweighted gene correlation network analysis (WGCNA)BiologyCohort StudiesEndometriumgenetic regulation of menstrual cyclePregnancymicroRNAGeneticsHumansEmbryo ImplantationMolecular BiologyGeneTranscription factorgene co-expressionDerepressionMenstrual cycleMenstrual Cycletranscription factormedia_commonrecurrent implantation failuremicroRNAObstetrics and GynecologyGene Expression Regulation DevelopmentalEmbryoCell BiologyGene signatureCell biologyendometrial transcriptomicsnuclear hormone receptorReproductive MedicineNuclear receptorEmbryo LossFemaleTranscriptomeDevelopmental Biology
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The performance of the INLSA in comparison with the ESPRIT and SAGE algorithms

2014

In this paper we investigate the application potential of three known algorithms, namely the ESPRIT, SAGE and INLSA, to properly emulate the statistical properties of the mobile fading channel. The performance comparisons of those methods will be carried out with respect to their fitting accuracy to the autocorrelation function (ACF) of the reference model. The methods' accuracy will be assessed in the synthetic reference channel model, which is based on the sum-of-cisoids (SOC) principle. In our reference model, we consider the scenarios with equal gains and Rayleigh distributed gains. The obtained results indicate that in both scenarios the INLSA method is more preferable than the ESPRIT …

EmulationComputer scienceAutocorrelationFadingData_CODINGANDINFORMATIONTHEORYChannel modelsAlgorithmReference modelComputer Science::Information TheoryCommunication channel2014 International Conference on Advanced Technologies for Communications (ATC 2014)
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Estudio piloto de la validez convergente de la adaptación española del Denison Organizational Culture Survey

2016

espanolEl (DOCS, Cuestionario de Cultura Organizacional de Denison) es uno de los instrumentos mas utilizados en el analisis de la cultura organizacional. El objetivo de este articulo es analizar la validez convergente de la version en espanol del DOCS. Para ello hemos empleado otro instrumento de gran relevancia y utilizacion en el campo de la psicologia de las organizaciones, el Organizational Culture Inventory (OCI, Inventario de Cultura Organizacional) de Cooke y Lafferty. Hemos evaluado la validez convergente de estos cuestionarios por medio de correlaciones de Pearson, utilizando una muestra de 344 miembros de una universidad espanola pertenecientes a diferentes equipos de investigaci…

EncuestaValidez de ConstructoResearch groups05 social sciencesPsychometric equivalence050109 social psychologySpanish versionGeneral MedicineCultura OrganizativaEscala0502 economics and businessCorrelation analysisPsicología organizacional0501 psychology and cognitive sciencesPoor correlationSociologyMediciónHumanities050203 business & managementEscritos de Psicología - Psychological Writings
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Transcultural adaptation and validation of Italian Selfcarediabetic foot questionnaire

2021

[Abstract] The Italian Self care diabetic foot questionnaire, (SDFQ-IT) is considered a dia-betic foot self-care evaluation tool with 16 questions for assessing diabetic foothealth disorders. To date, SDFQ has been validated in different languages, butan Italian version was lacking. Consequently, the purpose of this study was totranslate and validate the Italian version of the SDFQ-I T (SDFQ-IT). A suitablemethod was developed for the translation protocol and cross-cultural valida-tion from Spanish to Italian. Regarding the total marks from each sub-scale,agreement degrees, and confidence were analysed using the Cronbach's α andintraclass correlation coefficient (IC C), respectively. In add…

Encuestamedicine.medical_specialtyIntraclass correlationAutocuidadoDermatologyPie diabéticoAppropriate useEnquestesAutogestión030207 dermatology & venereal diseases03 medical and health sciences0302 clinical medicineCronbach's alphaSurveys and QuestionnairesDiabetes MellitusmedicineSelf-managementHumans030212 general & internal medicineself‐careReliability (statistics)LanguageDiabetisbusiness.industryQuestionnairequestionnaireReproducibility of ResultsOriginal ArticlesRepeatabilitymedicine.diseaseDiabetic footDiabetic FootSelf CareExtremitatsDiabetic footItalyself‐managementSelf carePhysical therapyOriginal ArticleSurgerySelf-carebusinessFoot (unit)
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Construction and validation of a computer-based diagnostic module on average velocity

1994

This article describes the process of building a computer-based diagnostic module concerning the understanding of the average velocity concept. The first step consists of the production of a student model that takes into account student errors and reasoning paths. The computer module formulates its diagnosis by leading users along different patterns foreseen according to the hypothesized student model. Results are reported concerning a correlation analysis between automatic and human diagnoses.

Engineering drawingConcept learningCorrelation analysisProcess (computing)Computer basedApplied mathematicsComputer moduleMedical diagnosisMotion (physics)EducationJournal of Research in Science Teaching
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Design of Wideband MIMO Car-to-Car Channel Models Based on the Geometrical Street Scattering Model

2012

Published version of an article in the journal: Modelling and Simulation in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2012/264213 Open access We propose a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on the geometrical street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. The proposed channel model assumes an infinite number of scatterers, which are uniformly distributed in two rectangular areas located on both sides of the street. Analytical solutions a…

EngineeringArticle Subjectbusiness.industryAutocorrelationMIMOGeneral EngineeringFunction (mathematics)Correlation function (quantum field theory)lcsh:QA75.5-76.95Computer Science Applicationssymbols.namesakeNon-line-of-sight propagationModeling and SimulationVDP::Technology: 500::Information and communication technology: 550::Telecommunication: 552Electronic engineeringsymbolslcsh:Electronic computers. Computer scienceWidebandbusinessDoppler effectReference modelAlgorithmModelling and Simulation in Engineering
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Modeling traffic safety at urban four leg-signalized intersections

2013

According to the state-of-the-art of the methodologies, the development of safety performance functions (SPFs) for road sections and intersections requires the employment of statistical models to predict expected crash frequencies on the basis of traffic volumes and site characteristics to be surveyed and used as input to models. Nevertheless, literature reports several studies on issues deriving from data features or methodological approaches that may invalidate the efficiency of the models and the accuracy of the estimates. Drawing inspiration from the above mentioned considerations, the objective of this study is to develop safety performance functions for a sample of urban four leg-sign…

EngineeringBasis (linear algebra)urban signalized intersectionsbusiness.industryCrashSample (statistics)Statistical modelTemporal correlationtransportation safetyTransport engineeringcrash analysissafety performance functionTraffic crashSettore ICAR/04 - Strade Ferrovie Ed AeroportiStatistical dispersionCrash databusiness
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A Novel Wideband MIMO Car-to-Car Channel Model Based on a Geometrical Semi-Circular Tunnel Scattering Model

2016

In this paper, we present a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on a geometrical semi-circular tunnel (SCT) scattering model. From the geometrical SCT scattering model, a reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. In the proposed reference channel model, it is assumed that an infinite number of scatterers are randomly distributed on the tunnel wall. Starting from the geometrical scattering model, the time-variant transfer function (TVTF) is derived, and its correlation properties in time, frequency, and space are studied. Expressions ar…

EngineeringComputer Networks and Communicationsbusiness.industryAutocorrelationMathematical analysisMIMOAerospace Engineering020206 networking & telecommunications020302 automobile design & engineering02 engineering and technologyTransfer functionDelay spreadCorrelation function (statistical mechanics)0203 mechanical engineeringAutomotive Engineering0202 electrical engineering electronic engineering information engineeringElectronic engineeringElectrical and Electronic EngineeringWidebandbusinessReference modelCommunication channelIEEE Transactions on Vehicular Technology
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