The European Space Agency {\Gaia} mission: exploring the Galaxy

The {\Gaia} astrometric mission was approved by the European Space Agency in 2000 and the construction of the spacecraft and payload is on-going for a launch in late 2012. {\Gaia} will continuously scan the entire sky for 5 years, yielding positional and velocity measurements with the accuracies needed to produce a stereoscopic and kinematic census of about one billion stars throughout our Galaxy and beyond. The main scientific goal is to quantify early formation and the subsequent dynamic and chemical evolution of the Milky way. The stellar survey will have a completeness to $V = 20$ mag, with a precision of about 25 $\mu$as at 15 mag. The astrometric information will be combined with astrophysical data acquired through on-board spectrophotometry and spectroscopy, allowing the chemical composition and age of the stars to be derived. Data acquired and processed as a result of the {\Gaia} mission are estimated to amount to about 1 petabyte. One of the challenging problems is the close relationship between astrometric and astrophysical data, which involves a global iterative solution that updates instruments parameters, the attitude of the satellite, and the properties of the observed objects. The European community is organized to deal with {\Gaia} products: (a) the Data Processing and Analysis Consortium is a joint European effort in charge of preparation and execution of data processing, (b) the GREAT network is a platform for collaboration on the preparation of scientific exploitation.Comment: 5 pages, 6 figures, conference "Astronomy with Megastructures. Joint science with E-ELT and SKA" held 10 -14 May 2010, Crete, Greec

Blended Cognition

The central concept of this edited volume is "blended cognition", the natural skill of human beings for combining constantly different heuristics during their several task-solving activities. Something that was sometimes observed like a problem as “bad reasoning”, is now the central key for the understanding of the richness, adaptability and creativity of human cognition. The topic of this book connects in a significant way with the disciplines of psychology, neurology, anthropology, philosophy, logics, engineering, logics, and AI. In a nutshell: understanding better humans for designing better machines. It contains a Preface by the editors and 12 chapters

Crowd synchrony and quorum sensing in delay-coupled lasers

Crowd synchrony and quorum sensing arise when a large number of dynamical elements communicate with each other via a common information pool. Previous evidence in different fields, including chemistry, biology and civil engineering, has shown that this type of coupling leads to synchronization, when coupling is instantaneous and the number of coupled elements is large enough. Here we consider a situation in which the transmission of information between the system components and the coupling pool is not instantaneous. To that end, we model a system of semiconductor lasers optically coupled to a central laser with a delay. Our results show that, even though the lasers are non-identical due to their distinct optical frequencies, zero-lag synchronization arises. By changing a system parameter, we can switch between two different types of synchronization transition. The dependence of the transition with respect to the delay-coupling parameters is studied.Comment: 4 pages, 4 figure

Small-world behavior in a system of mobile elements

We analyze the propagation of activity in a system of mobile automata. A number r L^d of elements move as random walkers on a lattice of dimension d, while with a small probability p they can jump to any empty site in the system. We show that this system behaves as a Dynamic Small-World (DSW) and present analytic and numerical results for several quantities. Our analysis shows that the persistence time T* (equivalent to the persistence size L* of small-world networks) scales as T* ~ (r p)^(-t), with t = 1/(d+1).Comment: To appear in Europhysics Letter

Updated global fit to three neutrino mixing: status of the hints of theta13 > 0

We present an up-to-date global analysis of solar, atmospheric, reactor and accelerator neutrino data in the framework of three-neutrino oscillations. We discuss in detail the statistical significance of the observed "hint" of non-zero theta13 in the solar sector at the light of the latest experimental advances, such as the Borexino spectral data, the lower value of Gallium rate recently measured in SAGE, and the low energy threshold analysis of the combined SNO phase I and phase II. We also study the robustness of the results under changes of the inputs such as the choice of solar model fluxes and a possible modification of the Gallium capture cross-section as proposed by SAGE. In the atmospheric sector we focus on the latest results for nu_e appearance from MINOS and on the recent Super-Kamiokande results from the combined phases I, II and III, and we discuss their impact on the determination of theta13. Finally, we combine all the data into a global analysis and determine the presently allowed ranges of masses and mixing.Comment: 20 pages, 9 figures. Acknowledgments correcte

Robust Cosmological Bounds on Neutrinos and their Combination with Oscillation Results

We perform a global analysis of cosmological observables in generalized cosmologies which depart from $\Lambda$CDM models by allowing non-vanishing curvature $\Omega_k\neq 0$, dark energy with equation of state with $\omega\neq -1$, the presence of additional relativistic degrees of freedom $\Delta N_{\rm rel}$, and neutrino masses $\Omega_\nu\neq 0$. By combining the data from cosmic microwave background (CMB) experiments (in particular the latest results from WMAP-7), the present day Hubble constant (H0) measurement, the high-redshift Type-I supernovae (SN) results and the information from large scale structure (LSS) surveys, we determine the parameters in the 10-dimensional parameter space for such models. We present the results from the analysis when the full shape information from the LSS matter power spectrum (LSSPS) is included versus when only the corresponding distance measurement from the baryon acoustic oscillations (BAO) is accounted for. We compare the bounds on the neutrino mass scale in these generalized scenarios with those obtained for the 6+1 parameter analysis in $\Lambda{\rm CDM}+m_\nu$ models and we also study the dependence of those on the set of observables included in the analysis. Finally we combine these results with the information on neutrino mass differences and mixing from the global analysis of neutrino oscillation experiments and derive the presently allowed ranges for the two laboratory probes of the absolute scale of neutrino mass: the effective electron neutrino mass in single beta decay and the effective Majorana neutrino mass in neutrinoless $\beta\beta$ decay.Comment: 19 pages, 4 figures. Acknowledgments correcte

Applications of Cognitive Radio Networks

The term cognitive radio (CR), originally coined in the late 1990s, envisaged a radio that is aware of its operational environment so that it can dynamically and autonomously adjust its radio-operating parameters to accordingly adapt to the different situations. Cognition is achieved through the so-called cognitive cycle, consisting of the observation of the environment, the orientation and planning that leads to making appropriate decisions in accordance with specific operation goals, and finally, the execution of these decisions (e.g., access to the appropriate channel). Decisions can be reinforced by learning procedures based on the past observations and the corresponding results of prior actuations