Measuring Support to Agriculture in a Transition Economy in the Southern Balkans: The case of FYR Macedonia

As a candidate country to the EU and a member of the WTO there is a need for a comprehensive, transparent and internationally comparable assessment of the support to agriculture in Macedonia. OECD that has been measuring support to agriculture on a yearly basis, in its member countries as well as some other countries since the mid-1980s, offers a good tool for such a task. The method is known for its most important indicator, the Producer Support Estimate (PSE). Using this method, data on Macedonian agricultural policy measures, in place – partly or entirely - for the period 1999 to 2004, have been gathered and categorized in order to arrive at an estimate of the level of support.Producer support estimate (PSE), FYR Macedonia, trade protection, Agricultural and Food Policy,

Impulse approximation in the n p --> d pi^0 reaction reexamined

The impulse approximation (one-body operator) in the n p --> d pi^0 reaction is reexamined with emphasis on the issues of reducibility and recoil corrections. An inconsistency when one pion exchange is included in the production operator is demonstrated and then resolved via the introduction of "wave function corrections" which nearly vanish for static nucleon propagators. Inclusion of the recoil corrections to the nucleon propagators is found to change the magnitude and sign of the impulse production amplitude, worsening agreement with the experimental cross section by approximately 30%. A cutoff is used to account for the phenomenological nature of the external wave functions, and is found to have a significant impact up to approximately 2.5 GeV.Comment: Published versio

Development of an immersive game-based virtual reality training program to teach fire safety skills to children

Injuries from residential fires are often overlooked as a dangerous safety concern for children. While lectures and classroom learning techniques can be effective in mitigating this risk, studies have shown that kids retain information better if they are allowed to practice escape techniques. Virtual Reality (VR) has been used both to simulate situations that are too dangerous to practice in real life and as a tool to help children learn. This thesis presents the two stage development of the Fire Safety Project, a game-based VR training environment to increase children\u27s understanding of fire safety. In the first iteration students help firefighters to identify home fire hazards and then practice escaping from a simulated fire in a virtual environment. Surveys administered show that participants felt that they had learned something during training. Many young participants also wanted to have active control over the virtual environment. In response, the second iteration is more game-based and allows children to explore the environment independently and zap fire hazards with the help of a tracked 6DOF wand. A user study was carried out and results indicate that students enjoyed the program; however there were no concrete learning gains from the use of the VR simulation

Quantum Mechanics of Extended Objects

We propose a quantum mechanics of extended objects that accounts for the finite extent of a particle defined via its Compton wavelength. The Hilbert space representation theory of such a quantum mechanics is presented and this representation is used to demonstrate the quantization of spacetime. The quantum mechanics of extended objects is then applied to two paradigm examples, namely, the fuzzy (extended object) harmonic oscillator and the Yukawa potential. In the second example, we theoretically predict the phenomenological coupling constant of the $\omega$ meson, which mediates the short range and repulsive nucleon force, as well as the repulsive core radius.Comment: RevTex, 24 pages, 1 eps and 5 ps figures, format change

Dilepton production in proton-proton and quasifree proton-neutron reactions at 1.25 GeV

We investigate the pp --> pp e+e- and quasifree pn --> pn e+e- reactions within an effective Lagrangian model at the laboratory kinetic energy of 1.25 GeV for which experimental data have recently been reported by the HADES Collaboration. The model uses a meson-exchange approximation to describe the initial nucleon-nucleon (NN) scattering. Contributions to the reaction amplitudes are included from the NN bremsstrahlung as well as from the excitation, propagation and radiative decay of the Delta(1230) isobar state. It is found that the HADES data on the e+e- invariant mass distribution in the pp --> pp e+e- reaction are reproduced excellently by our model where the Delta isobar term dominates the spectrum. However, the quasifree pn --> pn e+e- cross sections are underpredicted in the invariant mass region of 0.40 - 0.55 GeV/c^2 even after including contributions of the eta Dalitz decay and the subthreshold production and decay of the rho^0 meson via the baryonic resonance N*(1520). In the case of the quasifree pn --> pn e+e- reaction, a strong sensitivity to the pion electromagnetic form factor is observed which helps to bring the calculated cross sections closer to the data in the higher dilepton mass region.Comment: 12 pages 3, figures, version to appear in Phys. Rev. C (Rapid Communications

Videoconferencing via satellite. Opening Congress to the people: Technical report

The feasibility of using satellite videoconferencing as a mechanism for informed dialogue between Congressmen and constituents to strengthen the legislative process was evaluated. Satellite videoconferencing was defined as a two-way interactive television with the TV signals transmitted by satellite. With videoconferencing, one or more Congressmen in Washington, D. C. can see, hear and talk with groups of citizens at distant locations around the country. Simultaneously, the citizens can see, hear and talk with the Congressmen

Quark Condensate in the Deuteron

We study the changes produced by the deuteron on the QCD quark condensate by means the Feynman-Hellmann theorem and find that the pion mass dependence of the pion-nucleon coupling could play an important role. We also discuss the relation between the many body effect of the condensate and the meson exchange currents, as seen by photons and pions. For pion probes, the many-body term in the physical amplitude differs significantly from that of soft pions, the one linked to the condensate. Thus no information about the many-body term of the condensate can be extracted from the pion-deuteron scattering length. On the other hand, in the Compton amplitude, the relationship with the condensate is a more direct one.Comment: to appear in Physics Review C (19 pages, 3 figures

Spin distribution of nuclear levels using static path approximation with random-phase approximation

We present a thermal and quantum-mechanical treatment of nuclear rotation using the formalism of static path approximation (SPA) plus random-phase approximation (RPA). Naive perturbation theory fails because of the presence of zero-frequency modes due to dynamical symmetry breaking. Such modes lead to infrared divergences. We show that composite zero-frequency excitations are properly treated within the collective coordinate method. The resulting perturbation theory is free from infrared divergences. Without the assumption of individual random spin vectors, we derive microscopically the spin distribution of the level density. The moment of inertia is thereby related to the spin-cutoff parameter in the usual way. Explicit calculations are performed for 56^Fe; various thermal properties are discussed. In particular, we demonstrate that the increase of the moment of inertia with increasing temperature is correlated with the suppression of pairing correlations.Comment: 12 pages, 8 figures, accepted for publication in Physical Review

Contours of constant pseudo-Brewster angle in the complex є plane and an analytical method for the determination of optical constants

The locus of all points in the complex plane of the dielectric function є[єr + jєi = |є| exp(jθ)], that represent all possible interfaces characterized by the same pseudo-Brewster angle θpB of minimum p reflectance, is derived in the polar form: |є| = l cos(ζ/3), where l = 2(tan2ΦpB)k, ζ = arccos(- cosθ cos2ΦpB/k3), and k = (1 - 2/3 sin2ΦpB)½. Families of iso-ΦpB contours for (I) 0° ≤ ΦpB ≤ 45° and (II) 45° ≤ ΦpB ≤ 75° are presented. In range I, an iso-ΦpB contour resembles a cardioid. In range II, the contour gradually transforms toward a circle centered on the origin as ΦpB increases. However, the deviation from a circle is still substantial. Only near grazing incidence (ΦpB \u3e 80°) is the iso-ΦpB contour accurately approximated as a circle. We find that |є| \u3c 1 for ΦpB \u3c 37.23°, and |є| \u3e 1 for ΦpB \u3e 45°. The optical constants n,k (where n + jk = є½ is the complex refractive index) are determined from the normal incidence reflectance R0 and ΦpB graphically and analytically. Nomograms that consist of iso-R0 and iso-ΦpB families of contours in the nk plane are presented. Equations that permit the reader to produce his own version of the same nomogram are also given. Valid multiple solutions (n,k) for a given measurement set (R0,φpB) are possible in the domain of fractional optical constants. An analytical solution of the (R0,ΦpB) → (n,k) inversion problem is developed that involves an exact (noniterative) solution of a quartic equation in |є|. Finally, a graphic representation is developed for the determination of complex є from two pseudo-Brewster angles measured in two different media of incidence