2,379 research outputs found

    Developing indicators to measure Technology Institutes` performance

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    Technology institutes (TIs) are non-profit innovation and technology organisations aimed to encourage competitiveness of firms. They are a key organisation in the Spanish National Innovation System because of their size and closeness to the productive sector. Despite this, there is a lack of studies trying to measure their performance and its determinants. This work sheds some light on this. We study the influence of operative, financial, organisational, relational and general variables on three measures of results: selffinance, impact and added value. Our conclusions show the relevance of this approach and are confirmed by grouping TIs according to their service supply characteristics.Publicad

    Developing indicators to measure Technology Institutes` performance.

    Get PDF
    Technology institutes (TIs) are non-profit innovation and technology organisations aimed to encourage competitiveness of firms. They are a key organisation in the Spanish National Innovation System because of their size and closeness to the productive sector. Despite this, there is a lack of studies trying to measure their performance and its determinants. This work sheds some light on this. We study the influence of operative, financial, organisational, relational and general variables on three measures of results: selffinance, impact and added value. Our conclusions show the relevance of this approach and are confirmed by grouping TIs according to their service supply characteristics.

    Baroclinic Vorticity Production in Protoplanetary Disks; Part I: Vortex Formation

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    The formation of vortices in protoplanetary disks is explored via pseudo-spectral numerical simulations of an anelastic-gas model. This model is a coupled set of equations for vorticity and temperature in two dimensions which includes baroclinic vorticity production and radiative cooling. Vortex formation is unambiguously shown to be caused by baroclinicity because (1) these simulations have zero initial perturbation vorticity and a nonzero initial temperature distribution; and (2) turning off the baroclinic term halts vortex formation, as shown by an immediate drop in kinetic energy and vorticity. Vortex strength increases with: larger background temperature gradients; warmer background temperatures; larger initial temperature perturbations; higher Reynolds number; and higher resolution. In the simulations presented here vortices form when the background temperatures are ∼200K\sim 200K and vary radially as r−0.25r^{-0.25}, the initial vorticity perturbations are zero, the initial temperature perturbations are 5% of the background, and the Reynolds number is 10910^9. A sensitivity study consisting of 74 simulations showed that as resolution and Reynolds number increase, vortices can form with smaller initial temperature perturbations, lower background temperatures, and smaller background temperature gradients. For the parameter ranges of these simulations, the disk is shown to be convectively stable by the Solberg-H{\o}iland criteria.Comment: Originally submitted to The Astrophysical Journal April 3, 2006; resubmitted November 3, 2006; accepted Dec 5, 200

    CoRoT's first seven planets: An overview

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    The up to 150 day uninterrupted high-precision photometry of about 100000 stars - provided so far by the exoplanet channel of the CoRoT space telescope - gave a new perspective on the planet population of our galactic neighbourhood. The seven planets with very accurate parameters widen the range of known planet properties in almost any respect. Giant planets have been detected at low metallicity, rapidly rotating and active, spotted stars. CoRoT-3 populated the brown dwarf desert and closed the gap of measured physical properties between standard giant planets and very low mass stars. CoRoT extended the known range of planet masses down to 5 Earth masses and up to 21 Jupiter masses, the radii to less than 2 Earth radii and up to the most inflated hot Jupiter found so far, and the periods of planets discovered by transits to 9 days. Two CoRoT planets have host stars with the lowest content of heavy elements known to show a transit hinting towards a different planet-host-star-metallicity relation then the one found by radial-velocity search programs. Finally the properties of the CoRoT-7b prove that terrestrial planets with a density close to Earth exist outside the Solar System. The detection of the secondary transit of CoRoT-1 at the 10−510^{-5}-level and the very clear detection of the 1.7 Earth radii of CoRoT-7b at 3.510−43.5 10^{-4} relative flux are promising evidence of CoRoT being able to detect even smaller, Earth sized planets.Comment: 8 pages, 19 figures and 3 table

    A Conley index study of the evolution of the Lorenz strange set

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    In this paper we study the Lorenz equations using the perspective of the Conley index theory. More specifically, we examine the evolution of the strange set that these equations posses throughout the different values of the parameter. We also analyze some natural Morse decompositions of the global attractor of the system and the role of the strange set in these decompositions. We calculate the corresponding Morse equations and study their change along the successive bifurcations. In addition, we formulate and prove some theorems which are applicable in more general situations. These theorems refer to Poincar\'{e}-Andronov-Hopf bifurcations of arbitrary codimension, bifurcations with two homoclinic loops and a study of the role of the travelling repellers in the transformation of repeller-attractor pairs into attractor-repeller ones.Comment: 22 pages, 1 figur

    Shape index, Brouwer degree and Poincar\'e-Hopf theorem

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    In this paper we study the relationship of the Brouwer degree of a vector field with the dynamics of the induced flow. Analogous relations are studied for the index of a vector field. We obtain new forms of the Poincar% \'{e}-Hopf theorem and of the Borsuk and Hirsch antipodal theorems. As an application, we calculate the Brouwer degree of the vector field of the Lorenz equations in isolating blocks of the Lorenz strange set
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