Videojuegos como parte del aprendizaje

La utilización del juego como motivación para el aprendizaje se ha utilizado siempre en edades tempranas pero no así en edades más avanzadas o edad adulta, ya que se consideraba una pérdida de tiempo. Sin embargo, en los últimos años al tomar importancia los videojuegos y la gamificación se tornó a revalorizar el juego y el aspecto lúdico, debido a que se ha constatado que su uso contribuye a desarrollar nuestra creatividad y a fijar mejor el aprendizaje debido al fuerte componente emocional. En el presente trabajo se presenta la metodología utilizada en la implementación de videojuego educativo de rol online, que permite a los alumnos aprender jugando.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Fundamental parameters of Be stars located in the seismology fields of COROT

In preparation for the COROT space mission, we determined the fundamental parameters (spectral type, temperature, gravity, vsini) of the Be stars observable by COROT in its seismology fields (64 Be stars). We applied a careful and detailed modeling of the stellar spectra, taking into account the veiling caused by the envelope, as well as the gravitational darkening and stellar flattening due to rapid rotation. Evolutionary tracks for fast rotators were used to derive stellar masses and ages. The derived parameters will be used to select Be stars as secondary targets (i.e. observed for 5 consecutive months) and short-run targets of the COROT mission. Furthermore, we note that the main part of our stellar sample is falling in the second half of the main sequence life time, and that in most cases the luminosity class of Be stars is inaccurate in characterizing their evolutionary status.Comment: 25 pages, 9 figures, Accepted for publication in A&

Videojuegos como parte del aprendizaje

La utilización del juego como motivación para el aprendizaje se ha utilizado siempre en edades tempranas pero no así en edades más avanzadas o edad adulta, ya que se consideraba una pérdida de tiempo. Sin embargo, en los últimos años al tomar importancia los videojuegos y la gamificación se tornó a revalorizar el juego y el aspecto lúdico, debido a que se ha constatado que su uso contribuye a desarrollar nuestra creatividad y a fijar mejor el aprendizaje debido al fuerte componente emocional. En el presente trabajo se presenta la metodología utilizada en la implementación de videojuego educativo de rol online, que permite a los alumnos aprender jugando.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Videojuegos como parte del aprendizaje

La utilización del juego como motivación para el aprendizaje se ha utilizado siempre en edades tempranas pero no así en edades más avanzadas o edad adulta, ya que se consideraba una pérdida de tiempo. Sin embargo, en los últimos años al tomar importancia los videojuegos y la gamificación se tornó a revalorizar el juego y el aspecto lúdico, debido a que se ha constatado que su uso contribuye a desarrollar nuestra creatividad y a fijar mejor el aprendizaje debido al fuerte componente emocional. En el presente trabajo se presenta la metodología utilizada en la implementación de videojuego educativo de rol online, que permite a los alumnos aprender jugando.Sociedad Argentina de Informática e Investigación Operativa (SADIO

How exactly did the Universe become neutral?

We present a refined treatment of H, He I, and He II recombination in the early Universe. The difference from previous calculations is that we use multi-level atoms and evolve the population of each level with redshift by including all bound-bound and bound-free transitions. In this framework we follow several hundred atomic energy levels for H, He I, and He II combined. The main improvements of this method over previous recombination calculations are: (1) allowing excited atomic level populations to depart from an equilibrium distribution; (2) replacing the total recombination coefficient with recombination to and photoionization from each level directly at each redshift step; and (3) correct treatment of the He I atom, including the triplet and singlet states. We find that the ionization fraction x_e = n_e/n_H is approximately 10% smaller at redshifts <~800 than in previous calculations, due to the non-equilibrium of the excited states of H, which is caused by the strong but cool radiation field at those redshifts. In addition we find that He I recombination is delayed compared with previous calculations, and occurs only just before H recombination. These changes in turn can affect the predicted power spectrum of microwave anisotropies at the few percent level. Other improvements such as including molecular and ionic species of H, including complete heating and cooling terms for the evolution of the matter temperature, including collisional rates, and including feedback of the secondary spectral distortions on the radiation field, produce negligible change to x_e. The lower x_e at low z found in this work affects the abundances of H molecular and ionic species by 10-25%. However this difference is probably not larger than other uncertainties in the reaction rates.Comment: 24 pages, including 18 figures, using emulateapj.sty, to appear in ApJ, the code recfast can be obtained at http://www.astro.ubc.ca/people/scott/recfast.html (in FORTRAN) and http://cfa-www.harvard.edu/~sasselov/rec/ (in C

Effects of gravitational darkening on the determination of fundamental parameters in fast rotating B-type stars

In this paper we develop a calculation code to account for the effects carried by fast rotation on the observed spectra of early-type stars. Stars are assumed to be in rigid rotation and the grid of plane-parallel model atmospheres used to represent the gravitational darkening are calculated by means of a non-LTE approach. Attention is paid on the relation between the apparent and parent non-rotating counterpart stellar fundamental parameters and apparent and true vsini parameters as a function of the rotation rate Omega/Omega_c, stellar mass and inclination angle. It is shown that omission of gravitational darkening in the analysis of chemical abundances of CNO elements can produce systematic overestimation or underestimation, depending on the lines used, rotational rate and inclination angle. The proximity of Be stars to the critical rotation is re-discussed by correcting not only the vsini of 130 Be stars, but also their effective temperature and gravity to account for stellar rotationally induced geometrical distortion and for the concomitant gravitational darkening effect. We concluded that the increase of the vsini estimate is accompanied by an even higher value of the stellar equatorial critical velocity, so that the most probable average rate of angular velocity of Be stars attains Omega/Omega_c ~ 0.88.Comment: 20 pages, 16 figures. Submitted for publication in A&

Bayesian hierarchical clustering for studying cancer gene expression data with unknown statistics

Clustering analysis is an important tool in studying gene expression data. The Bayesian hierarchical clustering (BHC) algorithm can automatically infer the number of clusters and uses Bayesian model selection to improve clustering quality. In this paper, we present an extension of the BHC algorithm. Our Gaussian BHC (GBHC) algorithm represents data as a mixture of Gaussian distributions. It uses normal-gamma distribution as a conjugate prior on the mean and precision of each of the Gaussian components. We tested GBHC over 11 cancer and 3 synthetic datasets. The results on cancer datasets show that in sample clustering, GBHC on average produces a clustering partition that is more concordant with the ground truth than those obtained from other commonly used algorithms. Furthermore, GBHC frequently infers the number of clusters that is often close to the ground truth. In gene clustering, GBHC also produces a clustering partition that is more biologically plausible than several other state-of-the-art methods. This suggests GBHC as an alternative tool for studying gene expression data. The implementation of GBHC is available at https://sites. google.com/site/gaussianbhc