301 research outputs found
Evaluación de la fragmentación en los Sistemas Regionales de Innovación: Una tipología para el caso de España
El presente artículo tiene por objeto la realización de una estimación de la conectividad de los Sistemas Regionales de Innovación (SRI) españoles. Para ello, evaluamos el fenómeno de la fragmentación explicada en términos de «fallos de sistema», los cuales habían sido descritos de forma fundamentalmente teórica. Por el contrario, nuestra aproximación emplea cuatro conjuntos de indicadores cuantitativos integrados en un marco interpretativo formado por los principales subsistemas del SRI. Así, los denominados: «brechas directivas», «brechas estructurales », «brechas de innovación» y el «valle de la muerte», son situados en el marco presentado para ser posteriormente analizados sobre los SRI de las Comunidades Autónomas españolas a partir de indicadores basados en datos explotados ad hoc por parte del Instituto Nacional de Estadística (INE) y de la Asociación Española de Entidades de Capital Riesgo (ASCRI). Simplificamos la dimensionalidad de la tabla resultante a través de la aplicación de técnicas multivariantes como el Análisis Factorial Múltiple (AFM) o el análisis clúster, las cuales nos conducen a la presentación de una nueva tipología para el caso de España. Descubrimos comportamientos asimétricos en lo que respecta a los «fallos de sistema» expuestos; lo cual podría justificar el diseño de medidas exclusivas para su corrección en atención a la singularidad manifestada por cada sistema observado
A New HDG Method for Dirichlet Boundary Control of Convection Diffusion PDEs II: Low Regularity
In the first part of this work, we analyzed a Dirichlet boundary control
problem for an elliptic convection diffusion PDE and proposed a new
hybridizable discontinuous Galerkin (HDG) method to approximate the solution.
For the case of a 2D polygonal domain, we also proved an optimal superlinear
convergence rate for the control under certain assumptions on the domain and on
the target state. In this work, we revisit the convergence analysis without
these assumptions; in this case, the solution can have low regularity and we
use a different analysis approach. We again prove an optimal convergence rate
for the control, and present numerical results to illustrate the convergence
theory
La definición: del paradigma de la tradición lexicográfica (y terminográfica) al discurso expositivo en textos técnicos; estrategias discursivas
Waterborne hybrid polyurethane coatings containing Casein as sustainable green flame retardant through different synthesis approaches
Waterborne polyurethane (WPU) dispersions were prepared for flame retardant coatings. Specifically, alkoxysilane-capped polycaprolactone-based WPUs were synthesized employing the acetone process, and Casein, as a green and sustainable flame retardant additive, was added by two different methods (in situ and ex situ). These two strategies made possible to evaluate the effect of the Polyurethane/Casein interaction in the final properties of the dispersions and films. FTIR and solid-state 29Si NMR, confirmed the formation of the siloxane network during film generation process. The addition of Casein during the synthesis (in situ) resulted in a covalent bonding between the polyurethane and Casein, which significantly increased the particle size. However, the incorporation after phase inversion of the WPU (ex situ), did not change the particle size. Tensile tests revealed that the covalent bond promoted an increase in the brittleness of the material compared to ex situ approach due to a better dispersion of the Casein in the system. TGA results showed that Casein increased the thermal stability of all the coatings, especially of those obtained by the ex situ route. Moreover, and according to the microscale combustion calorimeter (MCC) and vertical burning test (UL-94) measurements Casein delayed the combustion of the material. Consequently, due to their characteristics, these Casein-WPU dispersions could potentially be used as combustion retardant coatings, where good physicochemical properties are essential for effective performance.The funding received from University of the Basque Country (GIU19/077, predoctoral grant of M. Puyadena and postdoctoral grant of M. Cobos) and the Basque Government (IT1313-19, PIBA20/16) is gratefully acknowledged
Real-space grids and the Octopus code as tools for the development of new simulation approaches for electronic systems
Real-space grids are a powerful alternative for the simulation of electronic systems. One of the main advantages of the approach is the flexibility and simplicity of working directly in real space where the different fields are discretized on a grid, combined with competitive numerical performance and great potential for parallelization. These properties constitute a great advantage at the time of implementing and testing new physical models. Based on our experience with the Octopus code, in this article we discuss how the real-space approach has allowed for the recent development of new ideas for the simulation of electronic systems. Among these applications are approaches to calculate response properties, modeling of photoemission, optimal control of quantum systems, simulation of plasmonic systems, and the exact solution of the Schrödinger equation for low-dimensionality systems
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Time-dependent density-functional theory in massively parallel computer architectures: the octopus project
SKA Science Data Challenge 2: analysis and results
The Square Kilometre Array Observatory (SKAO) will explore the radio sky to
new depths in order to conduct transformational science. SKAO data products
made available to astronomers will be correspondingly large and complex,
requiring the application of advanced analysis techniques to extract key
science findings. To this end, SKAO is conducting a series of Science Data
Challenges, each designed to familiarise the scientific community with SKAO
data and to drive the development of new analysis techniques. We present the
results from Science Data Challenge 2 (SDC2), which invited participants to
find and characterise 233245 neutral hydrogen (Hi) sources in a simulated data
product representing a 2000~h SKA MID spectral line observation from redshifts
0.25 to 0.5. Through the generous support of eight international supercomputing
facilities, participants were able to undertake the Challenge using dedicated
computational resources. Alongside the main challenge, `reproducibility awards'
were made in recognition of those pipelines which demonstrated Open Science
best practice. The Challenge saw over 100 participants develop a range of new
and existing techniques, with results that highlight the strengths of
multidisciplinary and collaborative effort. The winning strategy -- which
combined predictions from two independent machine learning techniques to yield
a 20 percent improvement in overall performance -- underscores one of the main
Challenge outcomes: that of method complementarity. It is likely that the
combination of methods in a so-called ensemble approach will be key to
exploiting very large astronomical datasets.Comment: Under review by MNRAS; 28 pages, 16 figure
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