42,353 research outputs found
Inflation and Budget Deficit: What is the Relationship in Portugal?
The main causes of Portuguese inflation, based on annual data from 1954 to 1995, using the Johansen method, allows us to conclude that variation in Portuguese inflation is determined essentially by foreign inflation and by variation in the effective exchange rate of the Portuguese Escudo (PTE). In the long-term, the relationship between inflation rate and the growth rate of unit labour costs is almost unitary. However, the response of inflation change to the equilibrium error between inflation rate and changes in unit labour costs is slow and almost insignificant, while the response of unit labour costs to this disequilibrium is fast and significant, what suggests that the direction of causality is much more evident from the inflation rate on unit labour costs, than the reverse. The budget deficit as a percentage of GDP, are not significant in the short-term, in relation to variation in inflation as a dependent variable. However, it is significant in the relation to unit labour costs as a dependent variable, so we can have an indirect positive relation between inflation and lagged budget deficit.Inflation, Budget Deficit, Unit Roots, and Cointegration
Stability of Closed Timelike Geodesics
The existence and stability under linear perturbations of closed timelike
geodesics (CTGs) in Bonnor-Ward spacetime is studied in some detail. Regions
where the CTG exist and are linearly stable are exhibited.Comment: 5 pages, REvTex, discussion added. PLA, in pres
Modulation of near-field heat transfer between two gratings
We present a theoretical study of near-field heat transfer between two
uniaxial anisotropic planar structures. We investigate how the distance and
relative orientation (with respect to their optical axes) between the objects
affect the heat flux. In particular, we show that by changing the angle between
the optical axes it is possible in certain cases to modulate the net heat flux
up to 90% at room temperature, and discuss possible applications of such a
strong effect
Changing the University System Management: a study of the Italian scenario
Over recent years, the Italian University System has been handling a phase of deep
changes, which have had significant impact on its mission and on the way it operates.
The most important of these changes have been to the organisation of universities, their
recruitment procedures and in terms of improvements to the quality and efficiency of
the university system itself. In this perspective, the objective of this research was to carry
out a critical analysis of the process of change, with special reference to improving
efficiency by making the transition from cash-based accounting to accrual accounting. In
order to achieve this objective, the starting point was the legislation of reference that
sets out the terms for the move to financial accrual accounting. A comparative analysis
was then carried out at an international level, with the purpose of highlighting the
strengths and weaknesses identified during the implementation of these new
procedures within the public field. This was followed by an analysis of the details of the
theory defining the accounting principles to be used in the process of preparing
university’s financial statements. Finally, the study identified the main critical points
relating to implementation of the new accounting system, offering, at the same time,
several thoughts concerning possible subsequent analyses on this topic
Convergence of time averages of weak solutions of the three-dimensional Navier-Stokes equations
Using the concept of stationary statistical solution, which generalizes the
notion of invariant measure, it is proved that, in a suitable sense, time
averages of almost every Leray-Hopf weak solution of the three-dimensional
incompressible Navier-Stokes equations converge as the averaging time goes to
infinity. This system of equations is not known to be globally well-posed, and
the above result answers a long-standing problem, extending to this system a
classical result from ergodic theory. It is also showed that, from a
measure-theoretic point of view, the stationary statistical solution obtained
from a generalized limit of time averages is independent of the choice of the
generalized limit. Finally, any Borel subset of the phase space with positive
measure with respect to a stationary statistical solution is such that for
almost all initial conditions in that Borel set and for at least one Leray-Hopf
weak solution starting with that initial condition, the corresponding orbit is
recurrent to that Borel subset and its mean sojourn time within that Borel
subset is strictly positive.Comment: Version 2: fixed some typos; added some references; and expanded some
sentences and some remarks for the sake of clarit
Electromagnetic Energy, Absorption, and Casimir Forces. Inhomogeneous Dielectric Media
A general, exact formula is derived for the expectation value of the
electromagnetic energy density of an inhomogeneous absorbing and dispersive
dielectric medium in thermal equilibrium, assuming that the medium is well
approximated as a continuum. From this formula we obtain the formal expression
for the Casimir force density. Unlike most previous approaches to Casimir
effects in which absorption is either ignored or admitted implicitly through
the required analytic properties of the permittivity, we include dissipation
explicitly via the coupling of each dipole oscillator of the medium to a
reservoir of harmonic oscillators. We obtain the energy density and the Casimir
force density as a consequence of the van der Waals interactions of the
oscillators and also from Poynting's theorem.Comment: 13 pages, no figures. Updated version with generalization to finite
temperature and added example
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