Learning the Optimal Control of Coordinated Eye and Head Movements

Various optimality principles have been proposed to explain the characteristics of coordinated eye and head movements during visual orienting behavior. At the same time, researchers have suggested several neural models to underly the generation of saccades, but these do not include online learning as a mechanism of optimization. Here, we suggest an open-loop neural controller with a local adaptation mechanism that minimizes a proposed cost function. Simulations show that the characteristics of coordinated eye and head movements generated by this model match the experimental data in many aspects, including the relationship between amplitude, duration and peak velocity in head-restrained and the relative contribution of eye and head to the total gaze shift in head-free conditions. Our model is a first step towards bringing together an optimality principle and an incremental local learning mechanism into a unified control scheme for coordinated eye and head movements

Time calibration of the ANTARES neutrino telescope

The ANTARES deep-sea neutrino telescope comprises a three-dimensional array of photomultipliers to detect the Cherenkov light induced by upgoing relativistic charged particles originating from neutrino interactions in the vicinity of the detector. The large scattering length of light in the deep sea facilitates an angular resolution of a few tenths of a degree for neutrino energies exceeding 10 TeV. In order to achieve this optimal performance, the time calibration procedures should ensure a relative time calibration between the photomultipliers at the level of similar to 1 ns. The methods developed to attain this level of precision are described

Produção de porcelana de ossos e caracterização de suas propriedades técnicas Production of bone porcelain and characterization of its technical properties

A porcelana de cinza de ossos é amplamente aceita e alcança alto valor de mercado, entretanto, sua produção ainda é pouco difundida, de modo que sua fabricação e pesquisa são restritas a poucos países. Sendo o Brasil grande produtor de gado, apresenta grande potencial para a reciclagem de ossos, podendo-se encontrar aplicação destes em materiais cerâmicos. Neste trabalho foi feita uma análise comparativa das características técnicas entre uma formulação de porcelana obtida com cinzas de ossos conforme a receita tradicional inglesa e uma formulação de porcelana tradicional. Os resultados mostraram que a sinterização de porcelana de cinzas de ossos requer cuidados extras em ciclos rápidos de queima quando comparada à porcelana tradicional, devido a um menor intervalo de gresificação. No entanto, a maior resistência mecânica e as qualidades estéticas, destacando-se a elevada alvura, fazem desta porcelana bastante atrativa em termos de potencial de aplicações industriais.<br>Porcelains from bone ash are widely accepted and present high market value, however, their manufacture and research are still restricted to few countries. As a great producer of cattle, Brazil presents great potential for the recycling of cattle bone into ceramic materials. In this work, it was realized a comparative investigation of technical properties of a typical porcelain composition manufactured from bone ash according to English traditional composition and a traditional porcelain. The results revealed that it is more difficult to sinter bone porcelain in fast firing cycles, once it showed shorter firing intervals compared to traditional porcelains. However, the higher mechanical strength and better aesthetic qualities, especially its whiteness, make bone porcelains very attractive materials in terms of industrial applications potential

Species diversification – which species should we use?

Large detector systems for particle and astroparticle physics; Particle tracking detectors; Gaseous detectors; Calorimeters; Cherenkov detectors; Particle identification methods; Photon detectors for UV. visible and IR photons; Detector alignment and calibration methods; Detector cooling and thermo-stabilization; Detector design and construction technologies and materials. The LHCb experiment is dedicated to precision measurements of CP violation and rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN (Geneva). The initial configuration and expected performance of the detector and associated systems. as established by test beam measurements and simulation studies. is described. © 2008 IOP Publishing Ltd and SISSA

The ATLAS hadronic tile calorimeter: From construction toward-physics

The Tile Calorimeter, which constitutes the central section of the ATLAS hadronic calorimeter, is a non-compensating sampling device made of iron and scintillating tiles. The construction phase of the calorimeter is nearly complete, and most of the effort now is directed toward the final assembly and commissioning in the underground experimental hall. The layout of the calorimeter and the tasks carried out during construction are described, first with a brief reminder of the requirements that drove the calorimeter design. During the last few years a comprehensive test-beam program has been followed in order to establish the calorimeter electromagnetic energy scale, to study its uniformity, and to compare real data to Monte Carlo simulation. The test-beam setup and first results from the data are described. During the test-beam period in 2004, lasting several months, data have been acquired with a complete slice of the central ATLAS calorimeter. The data collected in the test-beam are crucial in order to study algorithms for hadronic energy reconstruction using single particles. The generalization of these algorithms to reconstruct jet energies will be the starting point for numerous physics studies in which jets play a leading role. The results obtained in applying these algorithms to simulated di-jet events are given in the last section of the note