63,357 research outputs found
Rapid internationalization and long-term performance: The knowledge link
Drawing on the knowledge-based view and organizational learning theory, we develop and test a set of hypotheses to provide a first attempt at analyzing the effect of speed of internationalization on long-term performance. Using a panel-data sample of Spanish listed firms (1986-2010), we find that there is an inverted U-shaped relationship between speed of internationalization and long-term performance. We also find that whereas technological knowledge steepens this relationship, the diversity of prior international experience flattens it. Our results contribute to the existing IB literature on the performance of FDI, cross-country knowledge transferability, and nonsequential entry
A track-before-detect labelled multi-Bernoulli particle filter with label switching
This paper presents a multitarget tracking particle filter (PF) for general
track-before-detect measurement models. The PF is presented in the random
finite set framework and uses a labelled multi-Bernoulli approximation. We also
present a label switching improvement algorithm based on Markov chain Monte
Carlo that is expected to increase filter performance if targets get in close
proximity for a sufficiently long time. The PF is tested in two challenging
numerical examples.Comment: Accepted for publication in IEEE Transactions on Aerospace and
Electronic System
Entanglement detection in coupled particle plasmons
When in close contact, plasmonic resonances interact and become strongly
correlated. In this work we develop a quantum mechanical model, using the
language of continuous variables and quantum information, for an array of
coupled particle plasmons. This model predicts that when the coupling strength
between plasmons approaches or surpasses the local dissipation, a sizable
amount of entanglement is stored in the collective modes of the array. We also
prove that entanglement manifests itself in far-field images of the plasmonic
modes, through the statistics of the quadratures of the field, in what
constitutes a novel family of entanglement witnesses. This protocol is so
robust that it is indeed independent of whether our own model is correct.
Finally, we estimate the amount of entanglement, the coupling strength and the
correlation properties for a system that consists of two or more coupled
nanospheres of silver, showing evidence that our predictions could be tested
using present-day state-of-the-art technology.Comment: 8 pages (6 main text + 2 supplemental), 3 figure
The June 2012 transit of Venus. Framework for interpretation of observations
Ground based observers have on 5/6th June 2012 the last opportunity of the
century to watch the passage of Venus across the solar disk from Earth. Venus
transits have traditionally provided unique insight into the Venus atmosphere
through the refraction halo that appears at the planet outer terminator near
ingress/egress. Much more recently, Venus transits have attracted renewed
interest because the technique of transits is being successfully applied to the
characterization of extrasolar planet atmospheres. The current work
investigates theoretically the interaction of sunlight and the Venus atmosphere
through the full range of transit phases, as observed from Earth and from a
remote distance. Our model predictions quantify the relevant atmospheric
phenomena, thereby assisting the observers of the event in the interpretation
of measurements and the extrapolation to the exoplanet case. Our approach
relies on the numerical integration of the radiative transfer equation, and
includes refraction, multiple scattering, atmospheric extinction and solar limb
darkening, as well as an up to date description of the Venus atmosphere. We
produce synthetic images of the planet terminator during ingress/egress that
demonstrate the evolving shape, brightness and chromaticity of the halo.
Guidelines are offered for the investigation of the planet upper haze from
vertically-unresolved photometric measurements. In this respect, the comparison
with measurements from the 2004 transit appears encouraging. We also show
integrated lightcurves of the Venus/Sun system at various phases during transit
and calculate the respective Venus-Sun integrated transmission spectra. The
comparison of the model predictions to those for a Venus-like planet free of
haze and clouds (and therefore a closer terrestrial analogue) complements the
discussion and sets the conclusions into a broader perspective.Comment: 14 pages; 14 figures; Submitted on 02/06/2012; A&A, accepted for
publication on 30/08/201
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