37,445 research outputs found
Time Series Modelling of Tourism Demand from the USA, Japan and Malaysia to Thailand
Even though tourism has been recognized as one of the key sectors for the Thai economy, international tourism demand, or tourist arrivals, to Thailand have recently experienced dramatic fluctuations. The purpose of the paper is to investigate the relationship between the demand for international tourism to Thailand and its major determinants. The paper includes arrivals from the USA, which represents the long haul inbound market, from Japan as the most important medium haul inbound market, and from Malaysia as the most important short haul inbound market. The time series of tourist arrivals and economic determinants from 1971 to 2005 are examined using ARIMA with exogenous variables (ARMAX) models to analyze the relationships between tourist arrivals from these countries to Thailand. The economic determinants and ARMA are used to predict the effects of the economic, financial and political determinants on the numbers of tourists to Thailand.
Formation of Relativistic Axion Stars
Axions and axion-like particles are compelling candidates for the missing
dark matter of the universe. As they undergo gravitational collapse, they can
form compact objects such as axion stars or even black holes. In this paper, we
study the formation and distribution of such objects. First, we simulate the
formation of compact axion stars using numerical relativity with aspherical
initial conditions that could represent the final stages of axion dark matter
structure formation. We show that the final states of such collapse closely
follow the known relationship of initial mass and axion decay constant .
Second, we demonstrate with a toy model how this information can be used to
scan a model density field to predict the number densities and masses of such
compact objects. In addition to being detectable by the LIGO/VIRGO
gravitational wave interferometer network for axion mass of eV, we show using peak statistics that for , there
exists a "mass gap" between the masses of axion stars and black holes formed
from collapse
Quantum Communication in Spin Systems With Long-Range Interactions
We calculate the fidelity of transmission of a single qubit between distant
sites on semi-infinite and finite chains of spins coupled via the magnetic
dipole interaction. We show that such systems often perform better than their
Heisenberg nearest-neighbour coupled counterparts, and that fidelities closely
approaching unity can be attained between the ends of finite chains without any
special engineering of the system, although state transfer becomes slow in long
chains. We discuss possible optimization methods, and find that, for any
length, the best compromise between the quality and the speed of the
communication is obtained in a nearly uniform chain of 4 spins.Comment: 15 pages, 8 eps figures, updated references, corrected text and
corrected figs. 1, 4 and
Oral cancer secretome: Identification of cancer-associated proteins
This study aims to identify cancer-associated proteins in the secretome of oral cancer cell lines. We have successfully established four primary cell cultures of normal cells with a limited lifespan without human telomerase reverse transcriptase (hTERT) immortalization. The secretome of these primary cell cultures were compared with that of oral cancer cell lines using 2DE. Thirty five protein spots were found to have changed in abundance. Unambiguous identification of these proteins was achieved by MALDI TOF/TOF. In silico analysis predicted that 24 of these proteins were secreted via classical or nonclassical mechanisms. The mRNA expression of six genes was found to correlate with the corresponding protein abundance. Ingenuity Pathway Analysis (IPA) core analysis revealed that the identified proteins were relevant in, and related to, cancer development with likely involvements in tumor growth, metastasis, hyperproliferation, tumorigenesis, neoplasia, hyperplasia, and cell transformation. In conclusion, we have demonstrated that a comparative study of the secretome of cancer versus normal cell lines can be used to identify cancer-associated proteins.Article Link: http://onlinelibrary.wiley.com/doi/10.1002/elps.201300126/abstrac
Modelling and evaluation of aircraft contrails for 4-dimensional trajectory optimisation
Contrails and aircraft-induced cirrus clouds are reputed being the largest components of aviation-induced global warming, even greater than carbon dioxide (CO2) exhaust emissions by aircraft. This article presents a contrail model algorithm specifically developed to be integrated within a multi-objective flight trajectory optimization software framework. The purpose of the algorithm is to supply to the optimizer a measure of the estimated radiative forcing from the contrails generated by the aircraft while flying a specific trajectory. In order to determine the precise measure, a comprehensive model is employed exploiting the Schmidt-Appleman criterion and ice-supersaturation regions. Additional parameters such as the solar zenith angle, contrail lifetime and spread are also considered. The optimization of flight trajectories encompassing such contrail model allows for selective avoidance of the positive radiative forcing conditions, such as only avoiding persistent contrails, or contrails which lead to negative radiative forcing. The model assesses the radiative forcing associated with 4-Dimensional (4D) trajectories in a 4D weather field, encompassing both the local time-of-day and the contrail lifetime. Some preliminary algorithm validation activities are presented, including a simulation case study involving a medium-range domestic flight of a turbofan aircraft from Melbourne to Brisbane
Erratum: Dirichlet Forms and Dirichlet Operators for Infinite Particle Systems: Essential Self-adjointness
We reprove the essential self-adjointness of the Dirichlet operators of
Dirchlet forms for infinite particle systems with superstable and
sub-exponentially decreasing interactions.Comment: This is an erratum to the work appeared in J. Math. Phys. 39(12),
6509-6536 (1998
Finite temperature Casimir pistons for electromagnetic field with mixed boundary conditions and its classical limit
In this paper, the finite temperature Casimir force acting on a
two-dimensional Casimir piston due to electromagnetic field is computed. It was
found that if mixed boundary conditions are assumed on the piston and its
opposite wall, then the Casimir force always tends to restore the piston
towards the equilibrium position, regardless of the boundary conditions assumed
on the walls transverse to the piston. In contrary, if pure boundary conditions
are assumed on the piston and the opposite wall, then the Casimir force always
tend to pull the piston towards the closer wall and away from the equilibrium
position. The nature of the force is not affected by temperature. However, in
the high temperature regime, the magnitude of the Casimir force grows linearly
with respect to temperature. This shows that the Casimir effect has a classical
limit as has been observed in other literatures.Comment: 14 pages, 3 figures, accepted by Journal of Physics
Ultrafast Photoinduced Formation of Metallic State in a Perovskite-type Manganite with Short Range Charge and Orbital Order
Femtosecond reflection spectroscopy was performed on a perovskite-type
manganite, Gd0.55Sr0.45MnO3, with the short-range charge and orbital order
(CO/OO). Immediately after the photoirradiation, a large increase of the
reflectivity was detected in the mid-infrared region. The optical conductivity
spectrum under photoirradiation obtained from the Kramers-Kronig analyses of
the reflectivity changes demonstrates a formation of a metallic state. This
suggests that ferromagnetic spin arrangements occur within the time resolution
(ca. 200 fs) through the double exchange interaction, resulting in an ultrafast
CO/OO to FM switching.Comment: 4 figure
A possible minimal gauge-Higgs unification
A possible minimal model of the gauge-Higgs unification based on the higher
dimensional spacetime M^4 X (S^1/Z_2) and the bulk gauge symmetry SU(3)_C X
SU(3)_W X U(1)_X is constructed in some details. We argue that the Weinberg
angle and the electromagnetic current can be correctly identified if one
introduces the extra U(1)_X above and a bulk scalar triplet. The VEV of this
scalar as well as the orbifold boundary conditions will break the bulk gauge
symmetry down to that of the standard model. A new neutral zero-mode gauge
boson Z' exists that gains mass via this VEV. We propose a simple fermion
content that is free from all the anomalies when the extra brane-localized
chiral fermions are taken into account as well. The issues on recovering a
standard model chiral-fermion spectrum with the masses and flavor mixing are
also discussed, where we need to introduce the two other brane scalars which
also contribute to the Z' mass in the similar way as the scalar triplet. The
neutrinos can get small masses via a type I seesaw mechanism. In this model,
the mass of the Z' boson and the compactification scale are very constrained as
respectively given in the ranges: 2.7 TeV < m_Z' < 13.6 TeV and 40 TeV < 1/R <
200 TeV.Comment: 20 pages, revised versio
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