337 research outputs found
Modelling and forecasting the UK tourism growth cycle in Algarve
Over the past three decades, Portugal has developed a strong economic dependence on tourism, which has several implications for the country's overall economic development. Tourism is an activity that is interrelated strongly with the economic system since Portugal as a whole and specific regions in particular rely on the performance of tourism for their economic activity. Moreover, because economic cycles affect tourism development, it is highly vulnerable to economic fluctuations. Most tourists who visit Portugal are from the European Union, especially Western Europe. Statistics are based on the number of overnight stays in hotel accommodation and other similar establishments. In 2005, the main source markets were the UK (30.7%), Germany (16.5%), Spain (11.5%), the Netherlands (6.8%), France (4.7%), Ireland (3.6%) and Italy (3.1%). These values show that the UK has the greatest share of visitors to Algarve. The purpose of this paper is to propose a modelling approach that best fits the tourism flow pattern in order to support forecasting. The paper contributes to our understanding of the relationship between economic cycles and tourism flows to Portugal (Algarve) and explores the potential of applying the diffusion index model proposed by Stock and Watson (1999, 2002) for tourism demand forecasting
Emissioin of Intermediate Mass Fragments During Fission
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
The Magnetic Field of the Solar Corona from Pulsar Observations
We present a novel experiment with the capacity to independently measure both
the electron density and the magnetic field of the solar corona. We achieve
this through measurement of the excess Faraday rotation due to propagation of
the polarised emission from a number of pulsars through the magnetic field of
the solar corona. This method yields independent measures of the integrated
electron density, via dispersion of the pulsed signal and the magnetic field,
via the amount of Faraday rotation. In principle this allows the determination
of the integrated magnetic field through the solar corona along many lines of
sight without any assumptions regarding the electron density distribution. We
present a detection of an increase in the rotation measure of the pulsar
J18012304 of approximately 160 \rad at an elongation of 0.95 from
the centre of the solar disk. This corresponds to a lower limit of the magnetic
field strength along this line of sight of . The lack of
precision in the integrated electron density measurement restricts this result
to a limit, but application of coronal plasma models can further constrain this
to approximately 20mG, along a path passing 2.5 solar radii from the solar
limb. Which is consistent with predictions obtained using extensions to the
Source Surface models published by Wilcox Solar ObservatoryComment: 16 pages, 4 figures (1 colour): Submitted to Solar Physic
Rotation measure variations for 20 millisecond pulsars
We report on variations in the mean position angle of the 20 millisecond
pulsars being observed as part of the Parkes Pulsar Timing Array (PPTA)
project. It is found that the observed variations are dominated by changes in
the Faraday rotation occurring in the Earth's ionosphere. Two ionospheric
models are used to correct for the ionospheric contribution and it is found
that one based on the International Reference Ionosphere gave the best results.
Little or no significant long-term variation in interstellar RM was found with
limits typically about 0.1 rad m yr in absolute value. In a few
cases, apparently significant RM variations over timescales of a few 100 days
or more were seen. These are unlikely to be due to localised magnetised regions
crossing the line of sight since the implied magnetic fields are too high. Most
probably they are statistical fluctuations due to random spatial and temporal
variations in the interstellar electron density and magnetic field along the
line of sight.Comment: Accepted for publication in Astrophysics & Space Scienc
Non-Thermal Behavior in Multifragment Decay
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Mayaro Fever Virus, Brazilian Amazon
In February 2008, a Mayaro fever virus (MAYV) outbreak occurred in a settlement in Santa Barbara municipality, northern Brazil. Patients had rash, fever, and severe arthralgia lasting up to 7 days. Immunoglobulin M against MAYV was detected by ELISA in 36 persons; 3 MAYV isolates sequenced were characterized as genotype D
Assessing the Evolutionary Nature of Multifragment Decay
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Solar Wind Turbulence and the Role of Ion Instabilities
International audienc
Recent Developments in Understanding Two-dimensional Turbulence and the Nastrom-Gage Spectrum
Two-dimensional turbulence appears to be a more formidable problem than
three-dimensional turbulence despite the numerical advantage of working with
one less dimension. In the present paper we review recent numerical
investigations of the phenomenology of two-dimensional turbulence as well as
recent theoretical breakthroughs by various leading researchers. We also review
efforts to reconcile the observed energy spectrum of the atmosphere (the
spectrum) with the predictions of two-dimensional turbulence and
quasi-geostrophic turbulence.Comment: Invited review; accepted by J. Low Temp. Phys.; Proceedings for
Warwick Turbulence Symposium Workshop on Universal features in turbulence:
from quantum to cosmological scales, 200
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