Search results for "36"

Revisión bibliográfica y análisis sobre b-learning y la socialización del alumnado en educación primaria

2021

espanolLa modalidad educativa de b-learning se incorporo al sistema educativo hace algunos anos y se ha implantado con fuerza, sobre todo a nivel universitario. El objetivo del estudio es analizar las investigaciones publicadas sobre b-learning en la etapa de Educacion Primaria a traves de una revision bibliografica centrada en los ultimos 5 anos. Aunque el estudio confirma que la tendencia no ha cambiado y el modelo sigue teniendo mas presencia en niveles superiores, poco a poco, se van viendo estudios sobre b-learning en Educacion Primaria. En su mayoria, son estudios enfocados a la eficacia en cuanto al rendimiento academico, pero podemos encontrar investigaciones donde el foco de estudi…

RADIOPROTECTION IN 2018: AN UPDATE

2018

Fluoroscopically-guided interventional procedures are performed in large numbers in Europe and in the United States. Radiation doses received by interventional radiologists can vary for the same type of procedure and for similar patient doses. Occupational radiation protection is a necessity whenever radiation is used in the practice of medicine. The International Commission on Radiological Protection is engaging against occupational radiation damages, publishing regular recommendations on dose limits. These limits are expressed as effective doses for the whole body and also as equivalent doses for particular regions or tissues of practitioners’ bodies. Shielding and personal protective clo…

A Velocity Estimation Technique for a Monocular Camera Using mmWave FMCW Radars

2021

Perception in terms of object detection, classification, and dynamic estimation (position and velocity) are fundamental functionalities that autonomous agents (unmanned ground vehicles, unmanned aerial vehicles, or robots) have to navigate safely and autonomously. To date, various sensors have been used individually or in combination to achieve this goal. In this paper, we present a novel method for leveraging millimeter wave radar’s (mmW radar’s) ability to accurately measure position and velocity in order to improve and optimize velocity estimation using a monocular camera (using optical flow) and machine learning techniques. The proposed method eliminates ambiguity in optical flow veloci…

Localization of Multi-Class On-Road and Aerial Targets Using mmWave FMCW Radar

2021

mmWave radars play a vital role in autonomous systems, such as unmanned aerial vehicles (UAVs), unmanned surface vehicles (USVs), ground station control and monitoring systems. The challenging task when using mmWave radars is to estimate the accurate angle of arrival (AoA) of the targets, due to the limited number of receivers. In this paper, we present a novel AoA estimation technique, using mmWave FMCW radars operating in the frequency range 77–81 GHz by utilizing the mechanical rotation. Rotating the radar also increases the field of view in both azimuth and elevation. The proposed method estimates the AoA of the targets, using only a single transmitter and receiver. The measurements are…

Classification of Targets Using Statistical Features from Range FFT of mmWave FMCW Radars

2021

Radars with mmWave frequency modulated continuous wave (FMCW) technology accurately estimate the range and velocity of targets in their field of view (FoV). The targeted angle of arrival (AoA) estimation can be improved by increasing receiving antennas or by using multiple-input multiple-output (MIMO). However, obtaining target features such as target type remains challenging. In this paper, we present a novel target classification method based on machine learning and features extracted from a range fast Fourier transform (FFT) profile by using mmWave FMCW radars operating in the frequency range of 77–81 GHz. The measurements are carried out in a variety of realistic situations, including p…

Longitudinal analysis of Spanish doctoral theses in education (1841-2012)

2014

This article analyzes the research output of doctoral theses in the field of Education defended in Spain from 1841-2012. It offers a quantified global and diachronic view of such series. As a landmark to note is the fact that until 1954, obtaining a doctoral degree was centralized at the Complutense University of Madrid. They are used as search engines bibliographic databases: TESEO and institutional repositories, and basic bibliography of the area to carry out the collection of the sample. The contrasting hypothesis is to verify whether the time series partially follows the pattern of growth of the science of Derek J. de Solla Price. The central finding is that the Spanish production of do…

The Euro and Monetary Policy Transparency

2002

This paper focuses on a possible explanation for the weakness of the euro, namely the lack of transparency of the European Central Bank's (ECB) monetary policy. In order to obtain a time-varying measure of monetary policy uncertainty in both the U.S. and Euroland, we estimate a Stochastic Volatility model using policy-adjusted short-term interest rates. We also analyze directly the impact of higher uncertainty on the euro-dollar exchange rate. The empirical findings are in line with those of other studies, and show that the U.S. Fed is more transparent than the ECB. This results in higher volatility of European interest rates, capital outflows, and a weaker euro vis-a-vis the U.S. dollar.

Procesos de cambio: la huella de las mujeres en la plataforma de afectadas por las hipotecas de Valencia

2017

Dairy calcium intake and lifestyle risk factors for bone loss in hiv-infected and uninfected mediterranean subjects

2012

Abstract Background Despite the reported high prevalence of osteoporosis in the human immunodeficiency virus (HIV)-population, there have been no previous studies examining dairy calcium intake and bone mineral density (BMD) in HIV-subjects. We assessed the prevalence of low BMD in HIV-infected and uninfected subjects and analyzed the effects of calcium intake, lifestyle and HIV-related risk factors on BMD. Methods One hundred and twelve HIV-infected subjects were consecutively enrolled. Seventy- six HIV-uninfected subjects matched for age and sex were enrolled as the control group. The HIV-subjects were interviewed about lifestyle habits and completed a weekly food-frequency questionnaire …

In Silico Analysis of Microarray-Based Gene Expression Profiles Predicts Tumor Cell Response to Withanolides

2012

Withania somnifera (L.) Dunal (Indian ginseng, winter cherry, Solanaceae) is widely used in traditional medicine. Roots are either chewed or used to prepare beverages (aqueous decocts). The major secondary metabolites of Withania somnifera are the withanolides, which are C-28-steroidal lactone triterpenoids. Withania somnifera extracts exert chemopreventive and anticancer activities in vitro and in vivo. The aims of the present in silico study were, firstly, to investigate whether tumor cells develop cross-resistance between standard anticancer drugs and withanolides and, secondly, to elucidate the molecular determinants of sensitivity and resistance of tumor cells towards withanolides. Usi…