Search results for "STATISTICS"
showing 10 items of 7671 documents
Calibrating the Operational Beam Width and Maximum Range of a Ship Radar Used for Bird Observations
2010
In order to analyse quantitative radar observations of bird movements, one needs to know the dimensions of the air space surveyed by the radar. The present study shows how to calibrate the operational beam width and the maximum range of any radar for cross sections for different body sizes of songbirds. The trial used an X-band fan beam ship radar of 25 KW (Furuno Fr-2125) and a captive balloon. Metal spheres of different diameters, fastened to the bottom of the balloon at defined distances, corresponding to the radar cross sections of song birds, were moved in all three dimensions of the air space. Simultaneously to the location by radar, the position of the suspended sphere was measured b…
Low-complexity AoA and AoD Estimation in the Transformed Spatial Domain for Millimeter Wave MIMO Channels
2021
High-accuracy angle of arrival (AoA) and angle of departure (AoD) estimation is critical for cell search, stable communications and positioning in millimeter wave (mmWave) cellular systems. Moreover, the design of low-complexity AoA/AoD estimation algorithms is also of major importance in the deployment of practical systems to enable a fast and resource-efficient computation of beamforming weights. Parametric mmWave channel estimation allows to describe the channel matrix as a combination of direction-dependent signal paths, exploiting the sparse characteristics of mmWave channels. In this context, a fast Transformed Spatial Domain Channel Estimation (TSDCE) algorithm was recently proposed …
Contribution of HVSR measures for seismic microzonation studies
2018
The HVSR method applied to seismic noise can be a very useful technique to map the site effects of the territory, to identify the thickness of the soft covering and so the depth of the seismic bedrock. The case of the urban area of Oliveri is presented. Because of its high seismic hazard this area has been subject of first level seismic microzonation. The town lies on a large coastal plain made of mixed fluvial/marine sediments, overlapping a deformed substrate. In order to identify points on the area probably suffering of relevant site effects and to define a preliminary Vs subsurface model, 23 HVSR measurements were performed. A clustering technique of continuous signals has been used to …
Social Emotional Competence, Learning Outcomes, Emotional and Behavioral Difficulties of Preschool Children: Parent and Teacher Evaluations
2022
This paper addresses the role of social emotional competence in the emotional and behavioral problems and learning outcomes of preschool children based on their parents’ and teachers’ evaluations. In this study, we compared the perceptions of teachers and parents when evaluating the same child using the multi-informant assessment. First, the associations and differences between both the informant evaluations were investigated. Second, the correlation of the social emotional competence and emotional, and behavioral difficulties among preschool children was analyzed, separately addressing their parents’ and teachers’ evaluations. Third, the role of the preschool children’s social emotional co…
Validez factorial de una escala de generatividad en español: ¿otra escala con efectos de método?
2017
Introducción: Erikson (1950) utilizó el término “generatividad” por primera vez y se refiere al estado de adultez en el ciclo de vida, lo que implica procreatividad, productividad y creatividad e impulsa el desarrollo de la propia identidad. Existen varias formas de medir la generatividad como las entrevistas, la observación directa, los estudios de caso o los cuestionarios de autoinforme. El método más utilizado es el autoinforme y, entre las escalas disponibles, una de las más destacadas es la Escala de Generatividad de Loyola (EGL). La EGL es una medida de autoinforme que consta de veinte ítems que miden un factor general de generatividad.Objetivo: este estudio examinó la validez factori…
Un análisis bibliométrico en el área de la Medicina: colaboración científica entre Brasil y España (2002-2011)
2016
[EN]: This study analyzes the development of Spanish-Brazilian collaborative scientific production in the field of medical research between 2002 and 2011, identifying the most productive institutions, the proportion of researchers from each country and bi-lateral collaborative networks. Data were gathered from the Scopus database, which offers broad, international coverage of multidisciplinary research. A study sample of 1,121 original scientific articles signed by 13,906 researchers were retrieved, on the basis of which the annual growth rate of Spanish-Brazilian medical research was calculated. A remarkably high degree of internationalization was found, with 121 countries participating in…
Test-retest reliability of a new self reported comprehensive questionnaire measuring frequencies of different modes of adolescents commuting to schoo…
2009
Published version of an article from the journal: International Journal of Behavioral Nutrition and Physical Activity Article available from: http://www.ijbnpa.org/content/6/1/68 Background: Studies assessing active commuting to school usually use simple questionnaires, and often is mode of commuting reported with a single questionnaire item only. The purpose of the present study is to report the test-retest reliability of a newly developed comprehensive questionnaire on active commuting to school and work among 6thgrade school children and their parents in Norway. Methods: A total of 106 pupils and 77 parents completed a questionnaire two times, 14 days apart. The questionnaire consisted o…
Competing factor structures of the Rosenberg Self-Esteem Scale (RSES) and its measurement invariance across clinical and non-clinical samples
2017
Abstract Although several studies have investigated the factor structure of the Rosenberg Self-Esteem Scale (RSES), there are still disagreements about it. The present study assessed: a) the goodness of fit of nine competing factor models for the RSES using data from a clinical sample of 855 women with eating/weight disorders; and b) its measurement invariance across clinical and non-clinical (n = 943) samples. A bifactor model, with a general self-esteem factor, plus positive and negative method factors, provided a better fit with the data than alternative models. However, the results showed the high reliability of the general self-esteem factor, and a low reliability of the two method fac…
Choosing Optimal Seed Nodes in Competitive Contagion.
2019
International audience; In recent years there has been a growing interest in simulating competitive markets to find out the efficient ways to advertise a product or spread an ideology. Along this line, we consider a binary competitive contagion process where two infections, A and B, interact with each other and diffuse simultaneously in a network. We investigate which is the best centrality measure to find out the seed nodes a company should adopt in the presence of rivals so that it can maximize its influence. These nodes can be used as the initial spreaders or advertisers by firms when two firms compete with each other. Each node is assigned a price tag to become an initial advertiser whi…
Estimation of total electricity consumption curves of small areas by sampling in a finite population
2016
International audience; Many studies carried out in the French electricity company EDF are based on the analysis of the total electricity consumption curves of groups of customers. These aggregated electricity consumption curves are estimated by using samples of thousands of curves measured at a small time step and collected according to a sampling design. Small area estimation is very usual in survey sampling. It is often addressed by using implicit or explicit domain models between the interest variable and the auxiliary variables. The goal here is to estimate totals of electricity consumption curves over domains or areas. Three approaches are compared: the rst one consists in modeling th…