Search results for " Statistical analysis"

showing 10 items of 25 documents

Urinary metabolomics of bronchopulmonary dysplasia (BPD): preliminary data at birth suggest it is a congenital disease

2014

Abstract Objective: Bronchopulmonary dysplasia (BPD) or chronic lung disease is one of the principal causes of mortality and morbidity in preterm infants. Early identification of infants at the greater risk of developing BPD may allow a targeted approach for reducing disease severity and complications. The trigger cause of the disease comprehends the impairment of the alveolar development and the increased angiogenesis. Nevertheless, the molecular pathways characterizing the disease are still unclear. Therefore, the use of the metabolomics technique, due to the capability of identifying instantaneous metabolic perturbation, might help to recognize metabolic patterns associated with the cond…

MalePediatricsmedicine.medical_specialtyNeonatal intensive care unitBirth weightUrinary systemProton Magnetic Resonance SpectroscopymetaboliteGestational AgeDiseaseMetabolomicsSettore MED/38 - Pediatria Generale E SpecialisticaIntensive Care Units NeonatalmedicineHumansInfant Very Low Birth WeightMetabolomicsmultivariate statistical analysisbusiness.industryInfant Newborn1H-NMRObstetrics and GynecologyGestational agemedicine.diseaseBronchopulmonary dysplasiaLow birth weightBronchopulmonary dysplasiaPediatrics Perinatology and Child HealthMetabolomeFemalemedicine.symptombusinessBiomarkersInfant Prematuremetabolomic
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Stochastic resonance in a metal-oxide memristive device

2021

Abstract The stochastic resonance phenomenon has been studied experimentally and theoretically for a state-of-art metal-oxide memristive device based on yttria-stabilized zirconium dioxide and tantalum pentoxide, which exhibits bipolar filamentary resistive switching of anionic type. The effect of white Gaussian noise superimposed on the sub-threshold sinusoidal driving signal is analyzed through the time series statistics of the resistive switching parameters, the spectral response to a periodic perturbation and the signal-to-noise ratio at the output of the nonlinear system. The stabilized resistive switching and the increased memristance response are revealed in the observed regularities…

Materials scienceStochastic modellingStochastic resonanceGeneral MathematicsGeneral Physics and AstronomyMemristor01 natural sciencesNoise (electronics)Signal010305 fluids & plasmaslaw.inventionsymbols.namesakelaw0103 physical sciencesstochastic resonance010301 acousticsCondensed matter physicsresistive switchingApplied MathematicsStatistical and Nonlinear PhysicsMemristoryttria-stabilized zirconium dioxideNonlinear systemAdditive white Gaussian noisesymbolstime series statistical analysis stochastic modelVoltagetantalum oxide
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Unveiling the Relationship Between Sea Surface Hydrographic Patterns and Tuna Larval Distribution in the Central Mediterranean Sea

2021

Thunnus thynnus (Atlantic bluefin tuna, ABT) and other tuna species reproduce in the Mediterranean Sea during the summer period. Despite the Central Mediterranean Sea, the Strait of Sicily in particular, being a key spawning site for many tuna species, little is known on the effects of oceanographic variability on their larval distribution in this area. The abundance and presence-absence of larval specimens for three tuna species (ABT, bullet tuna and albacore) were modeled in order to examine their relationships with environmental factors, by analysing historical in situ information collected during seven annual surveys (2010–2016). The results revealed that most tuna larvae for the three …

Mediterranean climateichthyoplanktonSciencespawningOcean EngineeringAquatic ScienceQH1-199.5OceanographyMediterranean seaAuxis rocheiAbundance (ecology)Auxis rochei ichthyoplankton Mediterranean Sea multivariate statistical analysis spawning Thunnus alalunga Thunnus thynnusThunnus alalungaWater Science and Technologymultivariate statistical analysisGlobal and Planetary ChangebiologyAlbacoreQfood and beveragesGeneral. Including nature conservation geographical distributionIchthyoplanktonbiology.organism_classificationOceanographyThunnus thynnusBullet tunaTunahuman activitiesThunnusFrontiers in Marine Science
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NMR spectroscopy evaluation of direct relationship between soils and molecular composition of red wines from Aglanico grapes

2010

1H NMR spectroscopy was employed to investigate the molecular quality of Aglianico red wines from the Campania region of Italy. The wines were obtained from three different Aglianico vineyards characterized by different microclimatic and pedological properties. In order to reach an objective evaluation of “terroir” influence on wine quality, grapes were subjected to the same winemaking procedures. The careful subtraction of water and ethanol signals from NMR spectra allowed to statistically recognize the metabolites to be employed in multivariate statistical methods: Principal Component Analysis (PCA), Discriminant Analysis (DA) and Hierarchical Clustering Analysis (HCA). The three wines we…

Nuclear Magnetic ResonanceSettore AGR/13 - Chimica AgrariaAnalytical chemistryMultivariate statistical analysiBiochemistryAnalytical ChemistryChemometricsEnvironmental ChemistryOrganic matterFood scienceSpectroscopyWinemakingTerroirWinechemistry.chemical_classificationterroirChemistrydigestive oral and skin physiologyfood and beveragesNuclear magnetic resonance spectroscopyNuclear Magnetic Resonance; Aglianico red wines; Multivariate statistical analysis; terroirAglianico red wineSoil waterPrincipal component analysisSettore AGR/16 - Microbiologia Agraria
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Génèse et évolution des compétences des élèves à la fin de l'école maternelle : éléments d'analyse à partir de données de panel et d'une expérimentat…

2012

We propose to study in this thesis, a key issue and relatively little discussed in the French research in educational sciences, it concerns the genesis of pupil learning and their evolution during the tuition. We mobilize a longitudinal data (Panel 1997) and the results of a musical experimentation in kindergarten to answer to these questions: How are structured the first acquisitions of pupils and how is it linked to the school context and socio-economic variables? How the cognitive abilities of students affect their academic performance? Are specific activities can improve academic skills through an increase in cognitive abilities? Implicative analysis conducted on panel data has revealed…

School learningExpérimentationCapacités cognitivesSkills[SHS.EDU]Humanities and Social Sciences/Education[SHS.EDU] Humanities and Social Sciences/Education[ SHS.EDU ] Humanities and Social Sciences/EducationMusic educationKindergartenMaternelleÉducation musicalePanel 1997Apprentissages scolairesAnalyse statistique implicativeCognitive capacitiesCompétencesImplicative statistical analysisExperimentation
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Misure di radioattività ambientale a Palermo: analisi statistica delle concentrazioni in aria di 7Be e 210Pb

2016

In questo lavoro sono presi in considerazione gli andamenti delle concentrazioni in aria di 7Be e, per un più limitato periodo di tempo di 210Pb, e si è proceduto ad una analisi statistica dei dati, prendendo in esame le serie temporali (integrandole per i dati mancanti) dei valori medi mensili e settimanali al fine di operare confronti omogenei con dati disponibili di altre zone geografiche. Sono state studiate le correlazioni fra le serie di dati per i due radionuclidi ed è stata effettuata l’analisi in frequenza al fine di evidenziare ciclicità stagionali. Le analisi effettuate mostrano l’importanza dei processi di trasporto in atmosfera e l’influenza dei parametri meteo-climatici (in pa…

Settore ING-IND/20 - Misure E Strumentazione NucleariEnvironmental radioactivity. Statistical analysis. 7Be. 210Pb.Radiaoattività ambientale. Analisi statistica. 7Be. 210Pb.Settore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Settore FIS/03 - Fisica Della Materia
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Scritti in onore di Pellegrino Capaldo

2014

La qualità dei servizi è stata riconosciuta come un rilevante aspetto caratterizzante la performance dell’azienda pubblica, analogamente alla capacità di operare secondo criteri di efficienza e nel rispetto dei vincoli di bilancio. Sebbene sia possibile riscontrare alcuni significativi casi di adozione di politiche di customer satisfaction nelle amministrazioni pubbliche italiane, a tutt’oggi il tema presenta significative criticità, specialmente in ordine agli aspetti metodologici e agli strumenti operativi che consentano di integrare dette politiche nel sistema di programmazione e controllo delle aziende che erogano tali servizi. Il presente lavoro adotta una diversa prospettiva di analis…

Settore SECS-P/07 - Economia AziendaleQuality in delivering public services has been recognised as a major issue challenging performance in the public sector as well as the ability to operate effectively and within budget constraints. Empirical findings shown by the literature demonstrate that concrete efforts have been produced towards the evaluation and improvement of satisfaction levels of citizens and other Public Administration’s ‘customers’. However still today this issue portrays many unresolved criticalities particularly concerning the methodological approaches and operative tools to adopt in order to integrate ‘customer satisfaction’ programs with the wider organisational control system in each public administration. This paper adopts a non-conventional view of the ‘customer satisfaction’ concept. This is currently meant as a matter of social reporting or even statistical analysis based on the users’ perceptions on the level of provided services by a given (front office) unit in the public sector. Here an inter-institutional perspective is adopted with a view to map the overall value chain leading to the final product delivered to citizens or the community. Inside this chain tracking the underlying administrative products delivered by back-office units to their ‘internal clients’ in the public administration is recommended as a fundamental step to understand how to improve performance in satisfying citizens’ needs. This should also require a proper link between the administrative units’ goals and performance measures to the desired efficiency and effectiveness of processes leading to the attainment of administrative products providing the basis of the final services delivered to the private sector. Based on first empirical findings from field analysis in the Italian context the paper aims to outline an approach which could assist both politicians and managers to better assess and improve performance according to a customer satisfaction perspective.
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Joint probability distributions for wind speed and direction. A case study in Sicily

2015

In this study we analyze data of hourly average wind speed and direction measured at three different sampling stations located in Sicily (Italy) and provide a statistical model for their joint probability density function. Singly truncated from below Normal Weibull mixture distribution and a linear combination of von Mises distributions are used to model wind speed and direction. Sites with heterogeneous local conditions (prevailing wind direction and/or elevation) have been considered in order to investigate the reliability of the model here taken into consideration.

Wind speed wind direction statistical analysis joint distributionsSampling (statistics)Statistical modelProbability density functionGeodesySettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Settore FIS/03 - Fisica Della MateriaWind speedPrevailing windsJoint probability distributionStatisticsMixture distributionGeologyWeibull distribution2015 International Conference on Renewable Energy Research and Applications (ICRERA)
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Telerilevamento e GIS per la valutazione e il monitoraggio delle isole di calore in ambiente urbano

2017

The techniques of spatial analysis and Remote Sensing represent an useful tool for the knowledge and the study of the Urban Heat Island phenomenon (English acronym UHI). In this study, among the different causes that lead to the generation of the event, those regarding physical features of the surface and the presence of different land use/cover such as: the high cover of urban areas and the lack of green areas have been examined. The Remote Sensing techniques allow to create maps of the land use/cover, then, in order to estimate the different in temperature due to the distance to the vegetation, the temperature of the bodies already tested have been compared with a thermal map. In detail t…

analisi spazialelcsh:GA109.5lcsh:GA101-1776isole di calore urbanoTelerilevamentoHeat Island Environment Green Infrastructure Remote Sensing MivisRemote SensingSpatial analysiSettore BIO/03 - Botanica Ambientale E Applicatalcsh:CartographyUrban Heat IslandRemote sensing Urban heat island Spatial statistical analysis.Landscapeterritoriolcsh:Cadastral mappingSettore ICAR/06 - Topografia E Cartografia
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Frequency Change Patterns across Proficiency Levels in Japanese EFL Learner Speech

2014

This study investigated the overall patterns of variation across seven oral proficiency levels of 1,263 Japanese EFL learners and native English speakers. The methodological approach combined a learner corpus, language processing techniques, and multivariate statistical analyses to identify patterns of language use. The largest spoken learner corpus in Japan, the National Institute of Information and Communications Technology Japanese Learner English (NICT JLE) Corpus was used for the analysis. This corpus consists of transcribed interviews with 1,281 learners and contains over one million running words of spoken English. The transcriptions were compared with data gathered from 20 native En…

frequency changemultivariate statistical analysislearner speechoral proficiencyforeign language learning
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