Search results for "Correlation"
showing 10 items of 2282 documents
It runs in the family?
2022
AbstractFamily background has been shown to be a strong determinant of educational attainment, yet relatively little is known about the role that family background plays in PhD attainment or in the selection into academic careers. In this study, we estimate sibling correlations from Finnish full population register data to comprehensively assess the importance of family background in selection into academia. Our results show that family background accounts for over a third of the overall variation in becoming a PhD and subsequently an academic — a share which is up to four times as large as implied by conventional comparisons by parental education. However, we did not find evidence that fam…
THE IMPACT OF ANXIETY ON SPEAKING IN ADOLESCENT AND ADULT GROUPS OF ENGLISH LEARNERS
2018
Aim: The aim of this article is to investigate the interdependence between adolescent and adult students’ anxiety and their foreign language speaking achievements. It has been proved that there is no correlation between adolescent learners’ anxiety and their speaking attainments in a foreign language as well as that there is a weak correlation between adult students’ anxiety and their speaking achievements.
 Method: The author of the study employed quantitative research. Data was collected from anxiety questionnaires completed by the students and from achievement sheets filled in by the English teacher based on five-minute speeches performed by adolescent and adult students.
 Conc…
Effects of defects on the tensile strength of short-fibre composite materials
2014
Abstract. Heterogeneous materials tend to fail at the weakest cross-section, where the presence of microstructural heterogeneities or defects controls the tensile strength. Short-fibre composites are an example of heterogeneous materials, where unwanted fibre agglomerates are likely to initiate tensile failure. In this study, the dimensions and orientation of fibre agglomerates have been analysed from three-dimensional images obtained by X-ray microtomography. The geometry of the specific agglomerate responsible for failure initiation has been identified and correlated with the strength. At the plane of fracture, a defect in the form of a large fibre agglomerate was almost inevitably found.…
Stress Assessment of Vestibular Endurance Training for Civil Aviation Flight Students Based on EEG
2021
AbstractObjectiveThe main goal of our study is to clarify the EEG characteristics of the stress response caused by vestibular endurance training under the real conditions.MethodsTen pilot trainees received a series of acute anti-vertigo training stimulations on the rotary ladder while recording electroencephalographic data (64 electrodes). Afterwards, the subject’s anti-vertigo ability was tested for the best performance after 1 month of training, and verifying whether it is relating to the EEG signals we collected before.Results(1) The absolute power ofαwaves in the C3 and C4 regions is same as the difference between 1 min before and 2 min after stimulation, and their activity is enhanced …
Borexino’s search for low-energy neutrino and antineutrino signals correlated with gamma-ray bursts
2017
International audience; A search for neutrino and antineutrino events correlated with 2350 gamma-ray bursts (GRBs) is performed with Borexino data collected between December 2007 and November 2015. No statistically significant excess over background is observed. We look for electron antineutrinos ( ν¯e ) that inverse beta decay on protons with energies from 1.8 MeV to 15 MeV and set the best limit on the neutrino fluence from GRBs below 8 MeV. The signals from neutrinos and antineutrinos from GRBs that scatter on electrons are also searched for, a detection channel made possible by the particularly radio-pure scintillator of Borexino. We obtain currently the best limits on the neutrino f…
Käsivedon muuttujien yhteys viidenkymmenen metrin vapaauinnin aikaan : uuden anturiteknologiaan perustuvan tehomittarin testaus
2017
Johdanto. Uimari on uidessaan käytännössä lähes koko vartalollaan kosketuksissa veteen. Vesi on väliaine, joka vastustaa uimarin etenemistä ja josta voiman ja vastavoiman periaatteen mukaisesti uimaria eteenpäin vievien voimien tukipinnat tulisi löytää. Veden viskoelastinen luonne luo omat erityispiirteensä eteenpäin suuntautuvien ja vastustavien voimien välille. Tässä tutkimuksessa keskitytään vapaauinnin käsivedon muuttujiin, joiden avulla pyritään arvioimaan uimarin käsivedon eteenpäin vieviä voimia ja niiden yhteyttä uintinopeuteen. Tämän lisäksi tutkitaan anturiteknologiaan perustuvan tehomittarin reliabiliteettia ja arvioidaan validiteettia. Menetelmät. Koehenkilöinä oli kansallisen j…
Comportamiento de las correlaciones producto-momento y tetracórica-policórica en escalas ordinales: un estudio de simulación
2017
El análisis estadístico multivariante de escalas de respuesta tipo Likert, dado su empleo generalizado, resulta un tema controvertido en la comunidad científica, principalmente desde la especificación del problema de la medida. Este trabajo tiene como objeto estudiar cómo afectan diversas condiciones de estas escalas ordinales al cálculo de los coeficientes de correlación producto-momento y tetracórico-policórico. Para ello, se aplica un estudio de simulación en el que se generaron 90 bases de datos con 10 ítems cada una, controlando las siguientes variables: número de categorías de respuesta, distribución simétrica o asimétrica de los datos, tamaño de la muestra y nivel de relación entre l…
Does Airbnb Disrupt the Private Rental Market? An Empirical Analysis for French Cities
2019
This article evaluates whether Airbnb rentals affect the rents in the private rental sector in eight cities in France. We estimate a hedonic equation for each city on individual data for apartments, allowing for heteroscedasticity and spatial error autocorrelation of unknown forms and using a large variety of structural and contextual characteristics of the apartments. We show that the density of Airbnb rentals puts upward pressure on rents in Lyon, Montpellier, and Paris, whereas it has no significant effect in other cities. If we restrict the analysis to the professional business of Airbnb rentals, which we define as the lodgings owned by an investor who rents either several “entire home…
Extracting Conditionally Heteroskedastic Components using Independent Component Analysis
2020
In the independent component model, the multivariate data are assumed to be a mixture of mutually independent latent components. The independent component analysis (ICA) then aims at estimating these latent components. In this article, we study an ICA method which combines the use of linear and quadratic autocorrelations to enable efficient estimation of various kinds of stationary time series. Statistical properties of the estimator are studied by finding its limiting distribution under general conditions, and the asymptotic variances are derived in the case of ARMA-GARCH model. We use the asymptotic results and a finite sample simulation study to compare different choices of a weight coef…