Rotation Modulations and Distributions of the Flare Occurrence Rates on the Surface of Five UV Ceti Type Stars

In this study, we considered stellar spots, stellar flares, and also the relation between these two magnetic proccesses that take place on UV Cet stars. In addition, the hypothesis about slow flares described by Gurzadyan (1986 Ap&SS, 125, 127) was investigated. All of these discussions were based on the results of three years of observations of UV Cet-type stars: AD Leo, EV Lac, V1005 Ori, EQ Peg, and V1054 Oph. First of all, the results show that stellar spot activity occurs on the stellar surface of EV Lac, V1005 Ori, and EQ Peg, while AD Leo does not show any short-term variability and V1054 Oph does not exhibit any variability. We report on new ephemerides for EV Lac, V1005 Ori, and EQ Peg, obtained from time-series analyses. The phases, computed at intervals of 0.10 phase length, where the mean flare occurence rates to obtain maximum amplitude; also, the phases of rotational modulation were compared in order to investigate whether there is any longitudinal relation between stellar flares and spots. Although the results show that flare events are related with spotted areas on stellar surfaces during some of the observing seasons, we did not find any clear correlation among them. Finally, it was tested whether slow flares are fast flares occurring on the opposite side of the stars according to the direction of the observers, as mentioned in a hypothesis developed by <A >Gurzadyan (1986). The flare occurence rates reveal that both slow and fast flares can occur in any rotational phases. The flare occurence rates of both fast and slow flares vary in the same way along the longitudes for all program stars. These results are not expected based on the case mentioned in the hypothesis.Comment: 24 pages, 15 figures, 6 tabels, 2011PASJ...63..427

Bayesian Estimation of DSGE Models: Is the Workhorse Model Identified?

Koop, Pesaran and Smith (2011) suggest a simple diagnostic indicator for the Bayesian estimation of the parameters of a DSGE model. They show that, if a parameter is well identified, the precision of the posterior should improve as the (artificial) data size T increases, and the indicator checks the speed at which precision improves. It does not require any additional programming; a researcher just needs to generate artificial data and estimate the model with different T. Applying this to Smets and Wouters'(2007) medium size US model, we find that while exogenous shock processes are well identified, most of the parameters in the structural equations are not.Bayesian Estimation, Dynamic stochastic general equilibrium models, Identification.

V1135 Herculis: a double-lined eclipsing binary with an Anomalous Cepheid

BVR light curves and radial velocities for the double-lined eclipsing binary V1135\,Her were obtained. The brighter component of V1135\,Her is a Cepheid variable with a pulsation period of 4.22433$\pm$0.00026 days. The orbital period of the system is about 39.99782$\pm$0.00233 days, which is the shortest value among the known Type\,II Cepheid binaries. The observed B, V, and R magnitudes were cleaned for the intrinsic variations of the primary star. The remaining light curves, consisting of eclipses and proximity effects, are obtained. Our analyses of the multi-colour light curves and radial velocities led to the determination of fundamental stellar properties of both components of the interesting system V1135\,Her. The system consists of two evolved stars, G1+K3 between giants and supergiants, with masses of M$_1$=1.461$\pm$0.054 \Msun ~and M$_2$=0.504$\pm$0.040 {\Msun} and radii of R$_1$=27.1$\pm$0.4 {\Rsun} and R$_2$=10.4$\pm$0.2 {\Rsun}. The pulsating star is almost filling its corresponding Roche lobe which indicates the possibility of mass loss or transfer having taken place. We find an average distance of d=7500$\pm$450 pc using the BVR magnitudes and also the V-band extinction. Location in the Galaxy and the distance to the galactic plane with an amount of 1300 pc indicate that it probably belongs to the thick-disk population. Most of the observed and calculated parameters of the V1135\,Her and its location on the color-magnitude and period-luminosity diagrams lead to a classification of an Anomalous Cepheid.Comment: 25 pages, 9 Tables, 9 Figures, Accepted Revista Mexicana de Astronom\'ia y Astrof\'isica. arXiv admin note: substantial text overlap with arXiv:1211.120

Bayesian Estimation of DSGE Models: Is the Workhorse Model Identified?

Koop, Pesaran and Smith (2011) suggest a simple diagnostic indicator for the Bayesian estimation of the parameters of a DSGE model. They show that, if a parameter is well identified, the precision of the posterior should improve as the (artificial) data size T increases, and the indicator checks the speed at which precision improves. It does not require any additional programming; a researcher just needs to generate artificial data and estimate the model with different T. Applying this to Smets and Wouters?(2007) medium size US model, we find that while exogenous shock processes are well identified, most of the parameters in the structural equations are not

Bayesian Estimation of DSGE models: Is the Workhorse Model Identified?

Koop, Pesaran and Smith (2011) suggest a simple diagnostic indicator for the Bayesian estimation of the parameters of a DSGE model. They show that, if a parameter is well identified, the precision of the posterior should improve as the (artificial) data size T increases, and the indicator checks the speed at which precision improves. It does not require any additional programming; a researcher just needs to generate artificial data and estimate the model with different T. Applying this to Smets and Wouters'(2007) medium size US model, we find that while exogenous shock processes are well identified, most of the parameters in the structural equations are not

AGENDA-SETTING, PROGRESS AND CHALLENGES FOR ENVIRONMENTAL POLICY TRANSFER IN THE GULF COOPERATION COUNCIL

This study analyzes policy convergence and coordination in policymaking for sustainability, taking place in the context of Gulf Cooperation Council (GCC). It explores the policy choices of GCC countries in relation to agenda-setting, policy learning, policy convergence and coordination as a case of South-South transfer in the Middle East region, which is a relatively understudied aspect of the intensive diversification efforts of Gulf States. The study concludes that limited regional integration among GCC countries makes their relations more difficult. Individual national interests are prioritized over regional policy transfer and convergence. Moreover, some members choose to position closer to Western and Global perspective on development agenda. Consequently, they are keener to adopt environmental policies

A comparative morphological, compositional and tl study of tenedos (Bozcaada) and Sile aeolianites, Turkey

Aeolianites are carbonate-cemented deposits of coastal dune sands, mostly of Quaternary age. Even though aeolianite exposures on the coasts of the Mediterranean Sea are frequent, very few records have been documented from the coasts of either the Aegean or the Black Sea. The present study deals with evaluating and comparing both compositions and thermoluminescence (TL) ages of two recently reported samples of coastal aeolianites. Both were recovered at the Turkish coasts of Tenedos (Bozcaada) island, Aegean Sea and Şile, Western Black Sea. In the latter case, being the first record for the specific coastal area, the oldest age obtained was dated at 158±25 ka while the youngest age yielded was 108±14 ka. These values imply that both deposition and cementation occurred during the high sea stand of marine isotope stage 5 (MIS 5). In the case of Tenedos, the aeolianites were deposited between the early stage of the oxygen isotope stage 2 period (OIS 2) and the very late phase of the oxygen isotope stage 3 period (OIS 3). These latter TL results are in excellent agreement with a previous study of the same complex after applying OSL. Besides the ages, a number of luminescent features and properties in conjunction with compositional data suggest the dissimilarity for the quartz samples extracted from the aeolianites recovered at these two sampling sites, excluding thus any transport from one sampling site to the other, despite the short distance of the two sampling sites and the meteorological data regarding the preferable wind directions between them.Publisher's Versio

Non-conventional monetary policies: QE and the DSGE literature

At the zero lower bound, the scale and scope of non-conventional monetary policies have become the key decision variables for monetary policy makers. In the UK, quantitative easing has involved the creation of a fund to purchase medium term dated government bonds with borrowed central bank reserves and so has increased the liquidity of the non-bank financial sector and temporarily eased the budget constraint of HMT. Some of these reserves have been used to increase the extent of capital held by banks and there have also been direct injections of capital into the banking system. We assess some of the issues arising from the three policies by using three separate DSGE models, which take seriously the role of financial frictions. We find that it is possible to correct the effects of a lower zero bound in DSGE models, by (i) offsetting the liquidity premium embedded in long term bonds and/or (ii) adopting countercyclical subsidies to bank capital able and/or (iii) the creation of central bank reserves that reduce the costs of loan supply. But the correct quantitative response and ongoing interaction with standard monetary policy remains an open question