FREE MARKET ACCESS FOR LDCS UNDER THE EBA INITIATIVE. AN EMPIRICAL ANALYSIS USING THE GRAVITY APPROACH

This paper assesses the effectiveness of the Everything But Arms (EBA) initiative launched by the EU in 2001. It evaluates whether EBA was effective in increasing the exports from LDCs to the EU over the period 1995-2006. After arguing that the impact of trade preferences should be estimated by using disaggregated trade flows rather than aggregated trade, the analysis is carried out by considering five products (cloves, coffee, crustaceans, molluscs and vanilla beans) which meet three selecting criteria related to the export intensity of EBA countries, to the real/actual preferences of EBA and to the intra-year distribution of EU tariffs. Furthermore, the exports share of the 5-selected goods with respect to national exports is never marginal and, in many cases, is higher than 60%. From an econometric perspective, we improve the reliability of results by giving more attention to the econometric setting and to measurement of the preferential treatment. The evidence is mixed and while this limits the possibility to draw a general conclusion about the role of EBA, it supports the decision to work using disaggregated data because the evidence provided allows us to gauge the sector specificities which would be hidden when analysing total trade. Results show a positive impact on the exports of crustaceans and vanilla of the preferential treatment granted by the EU under EBA, whereas the evidence is un-conclusive when considering the other three products.Trade preferences, EBA initiative, gravity model, Panel data

REGIONAL ECONOMIC DIVIDE AND THE ROLE OF TECHNOLOGICAL SPILLOVERS IN ITALY. EVIDENCE FROM MICRODATA

This paper assesses the impact of R&D efforts on production in the North and Centre-South of Italy by using a panel of 1203 manufacturing firms over the period 1998-2003. The estimations are based on a nonlinear translog production function augmented by a measure of R&D spillovers. This measure combines the geographical distance between firms, the technological similarity within each pair of firms and the technical efficiency of each firm. The estimation method takes into account the endogeneity of regressors and the potential sample selection issue regarding firms’ decision to invest in R&D. Results show that the external stock of technology exerts a higher impact in the Centre-South of Italy. Finally, it emerges that R&D capital and R&D spillovers are substitutes for Northern firms and complements for Centre-Southern firms.R&D spillovers, Italian economic divide, translog production function, technical efficiency

Italian Ministry Guidelines on SLD Students’ Special Educational Needs. Didactic Suggestions and Teachers' Training

The present work shows the pathway towards the granting of the right to study to SLD Students’ Special Educational Needs in the Italian school context, showing the didactic strategies, the compensatory tools and exemption measures, suggested by the recent Italian educational policy. It also faces up the theme of both headmaster and teacher’s training related to the same theme, in order to emphasize its characteristics. The work is also enriched by the description of a specific experience of educational research whose main aim is to focus on the teacher’s training needs in order to find new ways to improve the competence in dealing with the special educational needs of SLD students

Continuous dynamical decoupling magnetometry

Solid-state qubits hold the promise to achieve unmatched combination of sensitivity and spatial resolution. To achieve their potential, the qubits need however to be shielded from the deleterious effects of the environment. While dynamical decoupling techniques can improve the coherence time, they impose a compromise between sensitivity and bandwidth, since to higher decoupling power correspond higher frequencies of the field to be measured. Moreover, the performance of pulse sequences is ultimately limited by control bounds and errors. Here we analyze a versatile alternative based on continuous driving. We find that continuous dynamical decoupling schemes can be used for AC magnetometry, providing similar frequency constraints on the AC field and improved sensitivity for some noise regimes. In addition, the exibility of phase and amplitude modulation could yield superior robustness to driving errors and a better adaptability to external experimental scenarios

Algebraic synthesis of time-optimal unitaries in SU(2) with alternating controls

We present an algebraic framework to study the time-optimal synthesis of arbitrary unitaries in SU(2), when the control set is restricted to rotations around two non-parallel axes in the Bloch sphere. Our method bypasses commonly used control-theoretical techniques, and easily imposes necessary conditions on time-optimal sequences. In a straightforward fashion, we prove that time-optimal sequences are solely parametrized by three rotation angles and derive general bounds on those angles as a function of the relative rotation speed of each control and the angle between the axes. Results are substantially different whether both clockwise and counterclockwise rotations about the given axes are allowed, or only clockwise rotations. In the first case, we prove that any finite time-optimal sequence is composed at most of five control concatenations, while for the more restrictive case, we present scaling laws on the maximum length of any finite time-optimal sequence. The bounds we find for both cases are stricter than previously published ones and severely constrain the structure of time-optimal sequences, allowing for an efficient numerical search of the time-optimal solution. Our results can be used to find the time-optimal evolution of qubit systems under the action of the considered control set, and thus potentially increase the number of realizable unitaries before decoherence

The NV center as a quantum actuator: time-optimal control of nuclear spins

Indirect control of qubits by a quantum actuator has been proposed as an appealing strategy to manipulate qubits that couple only weakly to external fields. While universal quantum control can be easily achieved when the actuator-qubit coupling is anisotropic, the efficiency of this approach is less clear. Here we analyze the time-efficiency of the quantum actuator control. We describe a strategy to find time-optimal control sequence by the quantum actuator and compare their gate times with direct driving, identifying regimes where the actuator control performs faster. As an example, we focus on a specific implementation based on the Nitrogen-Vacancy center electronic spin in diamond (the actuator) and nearby carbon-13 nuclear spins (the qubits)

The Role of the New Technologies in the Italian Primary School: Historical and Educational Outlines

Education is a process which helps the growth of the students. Thanks to it students can grow, develop and become adult and qualified persons in different fields of the humans ’ activity. Hence, the school educates only when it supports the students in getting and developing their own skills and when it helps them to get new attitudes towards themselves as well as the human, natural and artificial world. In this perspective, the school cannot continue to be a mere teaching-learning environment, just making frontal lessons, even if with the support of advanced multimedia technologies, but it should, indeed, focus the attention on the learning processes. This is the deepest change that the school needs. The possibilities offered by the computers in the educational field are many, especially as support in special didactics. In this sense, the access to multimedia and telematics has caused the activation of an autonomous process to build knowledge. The interpersonal exchanges mediated by the computer can break the isolation of a disabled person. The introduction of multimedia in school can then enhance both the teacher and the student to help the cooperative dimension of the teaching / learning process. The school has to open itself to new technologies and help the students to select the necessary information for the construction of th