A Dual Band Belt Antenna

This paper presents an antenna structure design using a standard belt for wearable applications. The antenna arouse from a body of research work on wearable metallic structures functioning as antennas for wireless on-body networks

Interactive mixture of inhomogeneous dark fluids driven by dark energy: a dynamical systems analysis

We examine the evolution of an inhomogeneous mixture of non-relativistic pressureless cold dark matter (CDM), coupled to dark energy (DE) characterised by the equation of state parameter $w<-1/3$, with the interaction term proportional to the DE density. This coupled mixture is the source of a spherically symmetric Lema\^\ itre-Tolman-Bondi (LTB) metric admitting an asymptotic Friedman-Lema\^\ itre-Robertson-Walker (FLRW) background. Einstein's equations reduce to a 5-dimensional autonomous dynamical system involving quasi--local variables related to suitable averages of covariant scalars and their fluctuations. The phase space evolution around the critical points (past/future attractors and five saddles) is examined in detail. For all parameter values and both directions of energy flow (CDM to DE and DE to CDM) the phase space trajectories are compatible with a physically plausible early cosmic times behaviour near the past attractor. This result compares favourably with mixtures with the interaction driven by the CDM density in which conditions for a physically plausible past evolution are more restrictive. Numerical examples are provided describing the evolution of an initial profile that can be associated with idealised structure formation scenariosComment: 23 pages, IOP format, 8 figure

Estimating development effort in free/open source software projects by mining software repositories: A case study of OpenStack

Because of the distributed and collaborative nature of free/open source software (FOSS) projects, the development effort invested in a project is usually unknown, even after the software has been released. However, this information is becoming of major interest, especially-but not only-because of the growth in the number of companies for which FOSS has become relevant for their business strategy. In this paper we present a novel approach to estimate effort by considering data from source code management repositories. We apply our model to the OpenStack project, a FOSS project with more than 1,000 authors, in which several tens of companies cooperate. Based on data from its repositories and together with the input from a survey answered by more than 100 developers, we show that the model offers a simple, but sound way of obtaining software development estimations with bounded margins of error.Gregorio Robles, Carlos Cervig on and Jes us M. Gonz alez-Barahona, project SobreSale (TIN2011-28110). and The work of Daniel Izquierdo has been funded in part by the Torres Quevedo program (PTQ-12-05577

Anthropologie et mystique selon Henri de Lubac. «L'esprit de l'homme» ou la presence de Dieu en I'homme. [Reseña]

Reseña de £ric DE MOULINS BEAUFORT, Anthropologie et mystique selon Henri de Lubac. «L'esprit de l'homme» ou la presence de Dieu en I'homme, Les Ed. du CERF («£tudes Lubaciennes», III), Paris 2003, 928 pp., 13 x 21, ISBN 2-204-06716-4

La voluntad de creer. Un debate sobre la ética de la creencia. [Reseña]

Reseña de William K. CLIFFORD-William JAMES, La voluntad de creer. Un debate sobre la ética de la creencia, Tecnos, Madrid 2003, 180 pp., 11 x 18, ISBN 84-309-3970-9