An evaluation of macroeconomic policies in Greece within an optimal control theory framework

This study evaluates the effectiveness of fiscal (and monetary) policies on a set of macroeconomic objectives, giving explicit consideration to the alternative modes by which the budget deficits (or surpluses) are financed. The extent to which quantitative reductions in the share of the public sector is compatible with these objectives is also examined. The evaluation of optimal macroeconomic policies is undertaken in the context of the Greek economy, since the financial aspects of the budget have not received the necessary attention. The method of analysis is carried out within an optimization framework which employes an econometric model of the Greek economy estimated over the period 1957-75, and a quadratic objective function depicting the desires of the policy-makers. The specific characteristics of the Greek economy necessary for the construction of the econometric model and the specification of the objective function are discussed in Chapter 2. Chapter 3 deals with the theoretical considerations of the macroeconomic model and presents the optimization approach persued in the study. Chapter 4 presents the econometric model and discusses its dynamic characteristics and structure. The specification of the objective function and the optimization results are discussed in Chapter 5. The major findings of the study are summarized in Chapter 6

Emerging Evidence for Neolithic Ithaca

The article presents new evidence for the Neolithic habitation on Ithaca, consisting of ceramic and stone finds, recognised among material from the University of Ioannina excavations at the site of Agios Athanasios-School of Homer in the northwest part of Ithaca, Greece. The new Neolithic site is considered within the wider cultural context of the Ionian Islands, in the late 5th/4th millennium BC. Our current knowledge suggests a permanent Neolithic occupation at the site, as opposed to seasonal occupation or to a special purpose occupation. The Neolithic people at the School of Homer may have been part of a dynamic network of Late/Final Neolithic installations in Western Greece, engaging themselves in inter-regional communal connections along the routes of the most ancient seafaring in the Ionian Sea

Study of Two-Step Mechanisms in Pion Absorption on 6Li, 12C via Deuteron Emission

The (pi+,pd), and (pi+,dd) reactions were investigated with pions of 100 and 165 MeV kinetic energy on 6Li and 12C targets. In comparison with previously published (pi+,pp) data on the same targets and at the same beam energies, kinematic regions were identified in which the neutron pickup process n+p->d dominated the observed deuteron yield. The importance of this mechanism increases with energy, contributing half of the observed cross section at 165 MeV. The contribution of direct quasi-triton absorption is significant only at 100 MeV.Comment: 23 pages, 12 figure

ρ\rho - nucleus bound states in Walecka model

Possible formation of $\rho$ nucleus bound state is studied in the framework of Walecka model. The bound states are found in different nuclei ranging from $^3He$ to $^{208}Pb$. These bound states may have a direct bearing on the recent experiments on the photoproduction of $\rho$ meson in the nuclear medium.Comment: RevTeX fil

Subthreshold rho^0 photoproduction on 3He

A large reduction of the rho^0 mass in the nuclear medium is reported, inferred from dipion photoproduction spectra in the 1 GeV region, for the reaction 3He(gamma,pi+ pi-)X with a 10% duty factor tagged-photon beam and the TAGX multi-particle spectrometer. The energy range covered (800 < E(gamma) < 1120 MeV) lies mostly below the free rho^0 production threshold, a region which is believed sensitive to modifications of light vector-meson properties at nuclear-matter densities. The rho^0 masses extracted from the MC fitting of the data, m*(rho^0) = 642 +/- 40, 669 +/- 32, and 682 +/- 56 MeV/c^2 for E(gamma) in the 800-880, 880-960, and 960-1040 MeV regions respectively, are independently corroborated by a measured, assumption-free, kinematical observable. This mass shift, far exceeding current mean-field driven theoretical predictions, may be suggestive of rho^0 decay within the range of the nucleonic field.Comment: 40 pages, 13 figures, submitted to Phys. Rev.

Spin observables for the pd <-> pi+ t process around the Delta resonance

The proton analyzing power Ay0 and the deuteron tensor analyzing power T20 are evaluated for the pd pi+ t process, in the energy region around and above the Delta resonance. These calculations extend a previous analysis of the excitation function and differential cross-section, based on a model embodying one-- and two-body p-wave absorption mechanisms and isobar excitation. The three-nucleon bound state and the pd scattering state are evaluated through Faddeev techniques for both the Bonn and Paris potentials. The spin variables exhibit a greater sensitivity to the number of included three-nucleon partial waves than the cross-sections, while the role played by the initial-- or final-state interactions appears to be small. The results for the tensor analyzing power at backward angles show a non-negligible dependence on the potentials employed, consistently with what has been previously found for the cross-sections. The calculation of spin observables gives a clear indication that other reaction mechanisms (presumably s-wave two-body absorption) have to be included in the model, in order to reproduce the experimental data below the Delta-resonance, in analogy with the simpler pp pi+ d process.Comment: 14 pages, REVTeX, plus 6 figs., PostScript (PRC, to be published

Revealing the ancient city of Sikyon through the application of integrated geophysical approaches and 3D modelling

The ancient city of Sikyon is located in the northern Peloponnese covering an area of 250 ha on a plateau that rises about 4 km southwest of the Corinthian gulf.  Previous archaeological excavations revealed a limited number of monuments within the surroundings of the ancient agora. Since 2004, a consortium led by the University of Thessaly, the Institute for Mediterranean Studies/FORTH, the University of York and the 37th Ephorate of Prehistoric and Classical Antiquities initiated the Sikyon..

Shadowing in the nuclear photoabsorption above the resonance region

A model based on the hadronic fluctuations of the real photon is developed to describe the total photonucleon and photonuclear cross sections in the energy region above the nucleon resonances. The hadronic spectral function of the photon is derived including the finite width of vector-meson resonances and the quark-antiquark continuum. The shadowing effect is evaluated considering the effective interaction of the hadronic component with the bound nucleons within a Glauber-Gribov multiple scattering theory. The low energy onset of the shadowing effect is interpreted as a possible signature of a modification of the hadronic spectral function in the nuclear medium. A decrease of the $\rho$-meson mass in nuclei is suggested for a better explanation of the experimental data.Comment: 8 pages, 7 figure