286 research outputs found
La política de dividendos en los bancos privados españoles: modelos de comportamiento
Dividend Policy in Spanish Prívate Banks: Behavioral Models. The purpose of this paper is to verify different behavioral models in dividend policy. The research has been done with a sample of Spanish private banks which are divided in two periods: 1976-80 and 1981-85. We test the hypothesis of partíal adjustement and the hypothesis of adaptative expectations for both periods. We use an integration model which refunds the two assumptions. The empirical results show that in the first period of time we can accept that only one of the effects is instant, while during 1981-85 both efects are it.El propósito de este trabajo es contrastar diferentes modelos de comportamiento en política de dividendos. La investigación se efectúa sobre una muestra de bancos privados españoles, durante los subperiodos 1976-80 y 1981-85. Se contrastan tanto la hipótesis de ajuste parcial como la de contenido informativo, presentándose la estimación de un modelo integrado. Los resultados empíricos confirman que en el primer subperiodo podemos aceptar que sólo uno de los efectos es instantáneo, mientras que en el segundo ambos lo son
Low Power Implementation of Trivium Stream Cipher
This paper describes a low power hardware implementation of the Trivium stream cipher based on shift register parallelization techniques. The de-sign was simulated with Modelsim, and synthesized with Synopsys in three CMOS technologies with different gate lengths: 180nm, 130nm and 90 nm. The aim of this paper is to evaluate the suitability of this technique and compare the power consumption and the core area of the low power and standard implemen-tations. The results show that the application of the technique reduces power consumption by more than 20% with only a slight penalty in area and operating frequency.Junta de Andalucía P08-TIC-03674info:eu-repo/grantAgreement/EC/FP5/01867Ministerio de Ciencia e Innovación TEC2010-16870/MI
Spatiotemporal characterization of Ensemble Prediction Systems – the Mean-Variance of Logarithms (MVL) diagram
We present a novel approach to characterize and graphically represent the spatiotemporal evolution of ensembles using a simple diagram. To this aim we analyze the fluctuations obtained as differences between each member of the ensemble and the control. The lognormal character of these fluctuations suggests a characterization in terms of the first two moments of the logarithmic transformed values. On one hand, the mean is associated with the exponential growth in time. On the other hand, the variance accounts for the spatial correlation and localization of fluctuations. In this paper we introduce the MVL (Mean-Variance of Logarithms) diagram to intuitively represent the interplay and evolution of these two quantities. We show that this diagram uncovers useful information about the spatiotemporal dynamics of the ensemble. Some universal features of the diagram are also described, associated either with the nonlinear system or with the ensemble method and illustrated using both toy models and numerical weather prediction systems
Spatio-temporal error growth in the multi-scale Lorenz’96 model
The influence of multiple spatio-temporal scales on the error growth and predictability of atmospheric flows is analyzed throughout the paper. To this aim, we consider the two-scale Lorenz’96 model and study the interplay of the slow and fast variables on the error growth dynamics. It is shown that when the coupling between slow and fast variables is weak the slow variables dominate the evolution of fluctuations whereas in the case of strong coupling the fast variables impose a non-trivial complex error growth pattern on the slow variables with two different regimes, before and after saturation of fast variables. This complex behavior is analyzed using the recently introduced Mean-Variance Logarithmic (MVL) diagram
Metodologia orientada a la elección de FPGAs con prioridad en el consumo de potencia
En este trabajo se presenta una metodología de diseño
orientada a explorar el cada vez más amplio conjunto de FPGAs
con el fin de seleccionar la mejor opción. Los parámetros que se
utilizan para realizar la exploración son los recursos consumidos,
la frecuencia de operación y el consumo de potencia. Sobre este
último parámetro, el más difícil de medir, se hace un especial
énfasis. Se exploran dos fabricantes (Altera y Xilinx), dos familias
diferentes de cada fabricante y dos subfamilias dentro de cada
familia, una de la gama alta y otra de la gama baja. Esta
exploración se ha realizado implementando dos circuitos que
realizan la operación división de números de 64 bits usando dos
algoritmos con plena vigencia.España, Ministerio de Educación y Ciencia TEC2007-65105/MICEspaña, Junta de Andalucía TIC-360
Evolución futura de los ciclones con características tropicales en la cuenca mediterránea: efectos de utilizar modelos de alta resolución o con acoplamiento atmósfera-océano [XXXV Jornadas AME]
Ponencia presentada en: XXXV Jornadas Científicas de la AME y el XIX Encuentro Hispano Luso de Meteorología celebrado en León, del 5 al 7 de marzo de 2018.Los ciclones con características tropicales son poco frecuentes en la Cuenca Mediterránea debido a que las condiciones atmosféricas y oceánicas son poco favorables para su desarrollo y mantenimiento. En el Mar Mediterráneo, este tipo de ciclones son llamados medicanes (“Mediterranean Hurricanes”). En los últimos años, se han observado medicanes con una fuerte intensidad como el ocurrido en Noviembre de 2011 (Miglietta et al., 2013). Los medicanes están asociados a fenómenos extremos como son fuertes vientos, precipitaciones torrenciales y fuerte oleaje, afectando sobre todo a zonas costeras. El motivo principal para realizar este trabajo es el estudio de las proyecciones de futuro para este tipo de ciclones en la Cuenca Mediterránea mediante la utilización de modelos regionales de clima, analizando los efectos del acoplamiento océano-atmósfera y la alta resolución
Evolución futura de los ciclones con características tropicales en la cuenca mediterránea: efectos de utilizar modelos de alta resolución o con acoplamiento atmósfera-océano
Ponencia presentada en: XI Congreso de la Asociación Española de Climatología celebrado en Cartagena entre el 17 y el 19 de octubre de 2018.[ES]Los ciclones con características tropicales son poco frecuentes en la Cuenca
Mediterránea debido a que las condiciones atmosféricas y oceánicas son poco favorables para su desarrollo y mantenimiento. En el Mar Mediterráneo, este tipo de ciclones son llamados Medicanes (“Mediterranean Hurricanes”). El motivo principal para realizar este trabajo es el estudio de las proyecciones de futuro para este tipo de ciclones en la Cuenca Mediterránea mediante la utilización de modelos regionales de clima, analizando los efectos del acoplamiento océano-atmósfera y la alta resolución. El análisis ha sido realizado para el escenario de Clima Futuro RCP85 hasta 2100. Las simulaciones fueron hechas en el marco de trabajo de los programas europeos MedCORDEX y EuroCORDEX. El análisis de detección de Medicanes incluye el método de Picornell, (Picornell et al., 2001) para la detección de ciclones, adaptado a la detección de ciclones mesoescalares, y el empleo del metódo de Hart (Hart., 2003) para detectar ciclones que presenten estructura y características tropicales. Los primeros resultados obtenidos para dicho estudio, muestran una gran frecuencia e intensidad de Medicanes en modelos de alta resolución, en consonancia con resultados anteriores (Akhtar et al 2014). Al comparar los modelos acoplados y los no acoplados se detecta que en ambos se observa un descenso futuro del número de Medicanes, así como una intensidad mayor de éstos a finales del periodo de estudio, es decir se observan medicanes con características tropicales más marcadas y velocidades máximas de viento más altas.[EN]Cyclones with tropical characteristics are rare in the Mediterranean Sea, because atmospheric and oceanic conditions are unfavourable for their development and maintenance. In the Mediterranean Sea, this type of cyclones are called Medicanes (“Mediterranean Hurricanes”). The main aim of this work is the study of future projections for these type of cyclones in the Mediterranean basin with climate regional models, analysing the effect of the atmosphere-ocean coupling and high resolution. The analysis is realized for the future climate scenario RCP85 until 2100. The simulations were done in the framework of European projects MedCORDEX y EuroCORDEX. The analysis procedure includes the detection of cyclones with a method adapted for mesoscale cyclones (Picornell et al., 2001) and the application of Hart method (Hart, 2003) for analysing the structure of the cyclones and detecting tropical characteristic. The first results of this study show a greater frequency and intensity ofMedicanes in higher resolution models compared to lower resolution ones, in agreement with previous results (Akhtar et al 2014). The comparison of an air-sea coupled simulation with an uncoupled simulation shows interesting results: for present climate conditions, a higher medicane frequency is found in the uncoupled simulation, but during the last decades of present century more medicanes are detected in the coupled run. The projected future medicane decrease is therefore much smaller in the coupled run, pointing to complex and time-varying effects of air-sea coupling on this type of extreme phenomena
Regional climate projections over Spain: atmosphere. Future climate projections
Special Issue on climate over the Iberian Peninsula: an overview of CLIVAR-Spain coordinated science
Impact of ocean–atmosphere coupling on future projection of Medicanes in the Mediterranean sea
Cyclones with tropical characteristics called medicanes (“Mediterranean Hur-ricanes”) eventually develop in the Mediterranean Sea. They have large harm-ful potential and a correct simulation of their evolution in climate projections is important for an adequate adaptation to climate change. Different studies suggest that ocean–atmosphere coupled models provide a better representation of medicanes, especially in terms of intensity and frequency. In this work, we use the regionally-coupled model ROM to study how air-sea interactions affect the evolution of medicanes in future climate projections. We find that under the RCP8.5 scenario our climate simulations show an overall frequency decrease which is more pronounced in the coupled than in the uncoupled con-figuration, whereas the intensity displays a different behaviour depending on the coupling. In the coupled run, the relative frequency of higher-intensity medicanes increases, but this is not found in the uncoupled simulation. Also, this study indicates that the coupled model simulates better the summer mini-mum in the occurrence of medicanes, avoiding the reproduction of unrealisti-cally intense events that can be found in summer in the uncoupled model
Impact of Optimal Timing of Intake of Multi-Ingredient Performance Supplements on Sports Performance, Muscular Damage, and Hormonal Behavior across a Ten-Week Training Camp in Elite Cyclists: A Randomized Clinical Trial
[EN] Multi-ingredient performance supplements (MIPS), ingested pre- or post-workout, have been shown to increase physiological level effects and integrated metabolic response on exercise. The purpose of this study was to determine the efficacy of pre-and post-training supplementation with its own MIPS, associated with CHO (1 g·kg−1) plus protein (0.3 g·kg−1) on exercise-related benchmarks across a training camp for elite cyclists. Thirty elite male cyclists participated in a randomized non-placebo-controlled trial for ten weeks assigned to one of three groups (n = 10 each): a control group treated with CHO plus protein after training (CG); a group treated with MIPS before training and a CHO plus protein after training, (PRE-MIPS); a group treated with CHO plus protein plus MIPS after training, (POST-MIPS). Performance parameters included (VO2max, peak; median and minimum power (W) and fatigue index (%)); hormonal response (Cortisol; Testosterone; and Testosterone/Cortisol ratio); and muscle biomarkers (Creatine kinase (CK), Lactate dehydrogenase (LDH), and Myoglobin (Mb)) were assessed. MIPS administered before or after training (p ≤ 0.05) was significantly influential in attenuating CK, LDH, and MB; stimulating T response and modulating C; and improved on all markers of exercise performance. These responses were greater when MIPS was administered post-workout.S
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