Vibrational ladder-descending photostabilization of a weakly bound molecule: Quantum optimal control with a genetic algorithm

We propose an optical control scheme for driving a polar molecule from a high-lying vibrational level to a target low-lying one, within the same electronic state. The scheme utilizes an infrared chirped laser pulse with an analytical shape, whose parameters are optimized by means of a heuristic formulation of quantum optimal control based on a genetic algorithm. We illustrate this methodology computationally for a KRb Feshbach molecule in the lowest triplet electronic state

Entrando en cintura: implicaciones de política económica sobre la sostenibilidad de la deuda pública en la zona euro.

En este artículo se muestra el marco teórico implícito en la restricción presupuestaria intertemporal del gobierno. A partir de este, se realizan una serie de simulaciones sobre el problema de sostenibilidad de la deuda pública, y los sacrificios fiscales necesarios para juzgar el actual nivel de endeudamiento sostenible en algunos países de la zona Euro. En particular, Grecia, Portugal, Italia y España deben generar un superávit primario de 44.1%, 10.5%, 6.8% y 4.5% del PIB, respectivamente para mantener sus actuales niveles de endeudamiento. La situación de Reino unido, Alemania y Francia es diferente, puesto que pueden presentar déficits debido a la relación entre crecimiento esperado y tasa de interés

Tactical and operational management of wind energy systems with storage using a probabilistic forecast of the energy resource

The storage of energy facilitates the management of renewable energy systems by reducing the mismatch between the supplied energy and the forecasted production due to forecasting errors. The storage increases the reliability of the renewable energy system and enables participation in the electricity market by committing to the sale of electricity for the following day. Nevertheless, the inclusion of the energy storage capacity requires the development of new management policies. In this paper, we propose a management strategy for a renewable energy system with storage capacity that integrates tactical and operational decisions in a single mathematical model that makes use of an updated probabilistic wind speed forecast. Management policies are obtained by solving a sequence of rolling-horizon stochastic optimization problems whose formulation is inspired by the Stochastic Approximation Average technique. The management policies are illustrated by their application to wind-farms using hydrogen as the energy storage medium

Bayesian variable selection in generalized extreme value regression: modeling annual maximum temperature

In many applications, interest focuses on assessing relationships between covariates and the extremes of the distribution of a continuous response. For example, in climate studies, a usual approach to assess climate change has been based on the analysis of annual maximum data. Using the generalized extreme value (GEV) distribution, we can model trends in the annual maximum temperature using the high number of available atmospheric covariates. However, there is typically uncertainty in which of the many candidate covariates should be included. Bayesian methods for variable selection are very useful to identify important covariates. However, such methods are currently very limited for moderately high dimensional variable selection in GEV regression. We propose a Bayesian method for variable selection based on a stochastic search variable selection (SSVS) algorithm proposed for posterior computation. The method is applied to the selection of atmospheric covariates in annual maximum temperature series in three Spanish stations

The Velocity Dispersion Profile of the Remote Dwarf Spheroidal Galaxy Leo I: A Tidal Hit and Run?

(abridged) We present kinematic results for a sample of 387 stars located near Leo I based on spectra obtained with the MMT's Hectochelle spectrograph near the MgI/Mgb lines. We estimate the mean velocity error of our sample to be 2.4 km/s, with a systematic error of < 1 km/s. We produce a final sample of 328 Leo I red giant members, from which we measure a mean heliocentric radial velocity of 282.9 +/- 0.5 km/s, and a mean radial velocity dispersion of 9.2 +/- 0.4 km/s for Leo I. The dispersion profile of Leo I is flat out to beyond its classical `tidal' radius. We fit the profile to a variety of equilibrium dynamical models and can strongly rule out models where mass follows light. Two-component Sersic+NFW models with tangentially anisotropic velocity distributions fit the dispersion profile well, with isotropic models ruled out at a 95% confidence level. The mass and V-band mass-to-light ratio of Leo I estimated from equilibrium models are in the ranges 5-7 x 10^7 M_sun and 9-14 (solar units), respectively, out to 1 kpc from the galaxy center. Leo I members located outside a `break radius' (about 400 arcsec = 500 pc) exhibit significant velocity anisotropy, whereas stars interior appear to have isotropic kinematics. We propose the break radius represents the location of the tidal radius of Leo I at perigalacticon of a highly elliptical orbit. Our scenario can account for the complex star formation history of Leo I, the presence of population segregation within the galaxy, and Leo I's large outward velocity from the Milky Way. The lack of extended tidal arms in Leo I suggests the galaxy has experienced only one perigalactic passage with the Milky Way, implying that Leo I may have been injected into its present orbit by a third body a few Gyr before perigalacticon.Comment: ApJ accepted, 23 figures, access paper as a pdf file at http://www.astro.lsa.umich.edu/~mmateo/research.htm

Effects of exoplanetary gravity on human locomotor ability

At some point in the future, if mankind hopes to settle planets outside the Solar System, it will be crucial to determine the range of planetary conditions under which human beings could survive and function. In this article, we apply physical considerations to future exoplanetary biology to determine the limitations which gravity imposes on several systems governing the human body. Initially, we examine the ultimate limits at which the human skeleton breaks and muscles become unable to lift the body from the ground. We also produce a new model for the energetic expenditure of walking, by modelling the leg as an inverted pendulum. Both approaches conclude that, with rigorous training, humans could perform normal locomotion at gravity no higher than 4 $g_{\textrm{Earth}}$.Comment: 12 pages, 4 figures, to be published in The Physics Teache

Promoting Comprehension Strategies of Primary Grade Students Through Datacasting Materials for Distance Learning

Many online learners especially in resource-challenged schools struggled with learning gaps during the pandemic crisis. This study focuses on using cost effective datacasting learning materials for distance education that promote intermediate grade students’ self-regulation, reading and writing skills. Datacasting is the process of delivering computer (IP) data over a traditional television broadcast signal. Locally, where only some households have Internet access but many have television sets, datacasting affords greater learning opportunities. Guided by structure, interactivity, and the functional language teaching theory, this study used sequential explanatory design to explore the role of datacasting in a public elementary school in Cavite in the academic year 2021 to 2022. Analyses of students’ artifacts reveal that their levels ofautonomy are non-autonomous, semi-autonomous, and autonomous. Moreover, the data also show that when they navigated the materials, they used these types of comprehension strategies: preparational, organizational, elaboration, andmonitoring. Correlations between culminating writing activities and final writing scores were found, but are not statistically significant, which may be attributed to the pandemic-induced sample attrition. The results suggest a need to refine the learning materials following the multimedia principles of personalization and embodiment through judicious text choice and adaptation and task design. Pedagogical recommendations for the use of datacasting materials are also offered