Search results for "LEVEL"

Prediction of the difficulty level in a standardized reading comprehension test : contributions from cognitive psychology and psychometrics

2013

Esta investigación busca identificar posibles variables predictoras del nivel de dificultad de los ítems de comprensión de lectura utilizados en una prueba psicométrica estandarizada para la admisión a una institución universitaria. Se propusieron varios posibles predictores del nivel de dificultad, a saber: densidad proposicional, negaciones, estructura sintáctica, dificultad del vocabulario, presencia elementos de realce (palabras resaltadas tipográficamente), abstracción del ítem y grado de similitud entre opción correcta y texto relevante para resolver el ítem. Mediante el Modelo Logístico Lineal de Rasgo Latente se encontró que la cantidad de proposiciones, la estructura sintáctica y, …

Graphical THD minimization procedure for single phase five-level converters

2017

This paper proposes two graphycal procedure to mitigate h harmonics and to minimize the total harmonic distortion (THD), respectively. The paper considers a five-level inverter and fundamental frequency modulation: it computes the two switching angles able to reduce low order harmonics and able to minimize the THD. Simulation results are obtained and, in order to validate the proposed procedure, an experimental prototype is built and experimental results are carried out. The comparison between simulation and experimental results confirms the accuracy of the proposed graphycal procedure. It is shown that the switching angles to mitigate the third-fifth and the third-fifth-seventh harmonics e…

Soft Computing and Image Analysis

2000

The paper describes a soft approach to solve image analysis problems. Theory of fuzzy-sets has been used to implement most of the algorithms described in the paper. Soft approaches can be useful to extend mathematical morphology operators on gray level images and to describe the shape of dotted objects. Examples on real data are also provided.

The influence of ozone and aerosols on the experimental values of UV erythemal radiation at ground level in Valencia

2009

Ultraviolet erythemal radiation (UVER) values have been simulated for different values of column ozone and aerosol optical depth (AOD) using a multiple scattering model: SBDART. The results show that UVER decreased when atmospheric ozone and aerosols increased, with the ozone having greater influence than AOD. To quantify these dependencies the influence of aerosols on the simulated values of UVER has been analysed for different ozone values. This dependence was linear. Similarly, to quantify the influence of ozone on the UVER values this was simulated for fixed values of AOD while varying the column ozone. The expression of this dependence was found to be a second-order polynomial. We also…

Experimental values of the UV index during 2000 at two locations in Mediterranean Spain

2002

During the past 2 years automatic measurements of UVB solar irradiance have been made sstematically at ground level at a number of points in Spain. Values for both the ultraviolet erythemal radiation and the ultraviolet index (UVI) have been obtained from these measurements. In this paper we present a first analysis of these values for two locations on the Spanish Mediterranean coast—Valencia and Barcelona—an area where a large part of the summer tourism of the country is concentrated. During the summer the UVI only reached ten on three occasions, though a value of nine was reached repeatedly (both classified as extreme risk by the World Health Organization). It has been shown that, in 90% …

Deperturbation treatment of theAΣ+1–bΠ3complex of NaRb and prospects for ultracold molecule formation inXΣ+1(v=0;J=0)

2007

High resolution Fourier transform spectra (FTS) of laser induced fluorescence (LIF) of $C\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+};D\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Pi}\ensuremath{\rightarrow}A\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+}--b\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\Pi}$ and $A\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+}--b\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\Pi}\ensuremath{\rightarrow}X\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+}$ transitions in ${\mathrm{Na}}^{85}\mathrm{Rb}$ and ${\mathrm{Na}}^{87}\mathrm{Rb}$ were obtained. An analysis of the direct LIF spectra together with the rotational relaxation satellite…

Laser synthesis of ultracold alkali metal dimers: optimization and control

2015

Ausgeprägte Virilisierung in der Postmenopause - eine Falldarstellung

2005

Severe postmenopausal virilization is a rare event in clinical practice. To evaluate ovarian or adrenal hyperandrogenism endocrine tests and imaging are useful diagnostic tools. We report a case of a postmenopausal woman with hirsutism and androgenetic alopecia. A malignant cause for the present disorder could be excluded by imaging. Selective venous sampling was administered with increased testosterone level of the right adrenal vein. Right adrenalectomy and right oophorctomy was recommended.

Geological development of a gypsum lake formed at the beginning of the 20th century in central Sicily, Italy: Integration of historical data with mod…

2006

A limnological investigation was carried out on the small, endorheic lake, called Lake Sfondato, located in central Sicily (Italy). All the aquatic environments in the central part of the island are rich in salt, with conductivity values above 5 mS cm−1, and are characterized by high alkalinity values and hard waters. In addition, due to intensive agriculture, many of these ecosystems have experienced a strong anthropogenic eutrophication over the last decades. In order to better understand the functioning of these peculiar environments, the morphology, hydrology, and geochemistry, as well as several selected physical and biological characteristics of Lake Sfondato, were studied in the year…

33S hyperfine interactions in H2S and SO2 and revision of the sulfur nuclear magnetic shielding scale

2014

Using the Lamb-dip technique, the hyperfine structure in the rotational spectra of H2(33)S and (33)SO2 has been resolved and the corresponding parameters--that is, the sulfur quadrupole-coupling and spin-rotation tensors--were determined. The experimental parameters are in good agreement with results from high-level coupled-cluster calculations, provided that up to quadruple excitations are considered in the cluster operator, sufficiently large basis sets are used, and vibrational corrections are accounted for. The (33)S spin-rotation tensor for H2S has been used to establish a new sulfur nuclear magnetic shielding scale, combining the paramagnetic part of the shielding as obtained from the…