Quantum Randomness Certified by the Uncertainty Principle

We present an efficient method to extract the amount of true randomness that can be obtained by a Quantum Random Number Generator (QRNG). By repeating the measurements of a quantum system and by swapping between two mutually unbiased bases, a lower bound of the achievable true randomness can be evaluated. The bound is obtained thanks to the uncertainty principle of complementary measurements applied to min- and max- entropies. We tested our method with two different QRNGs, using a train of qubits or ququart, demonstrating the scalability toward practical applications.Comment: 10 page

On the correct surface stress for the prediction of the wind wave field and the storm surge in the Northern Adriatic Sea

This paper discusses which formulation of the surface stress over the sea determines the most accurate prediction of the wind wave field and storm surge in the Northern Adriatic Sea. The study shows that the results of the storm surge and wind wave models, when compared to the available observations, can be used for the validation of the surface stress and of the expression adopted for the ssr (sea surface roughness). The results are representative of short fetch and young wind sea conditions. The agreement between the results and the measurements shows the feasibility of the wind wave and storm surge predictions in the Adriatic Sea and supports the dependence of the ssr, and, therefore, of the surface stress, on the spectrum of the surface wave

The disastrous storm of 4 November 1966 on Italy

International audienceThis is the first modeling reconstruction of the whole aspects (both meteorological and oceanographic) of the storm which hit Italy on 4 November 1966, producing 118 victims and widespread damages in Tuscany, at the northern Adriatic coast and in the north-eastern Italian Alps. The storm was produced by a cyclone which formed in the western Mediterranean and moved eastward towards Italy, reaching the Thyrrenian Sea, and then northward. The most peculiar characteristic of the storm has been the strong zonal pressure gradient and the consequent intensity and long fetch of the south-easterly sirocco wind, which advected a large amount of warm moist air, and determined exceptional orographic precipitation over Tuscany and the north-eastern Alps. The funneling of the wind between the mountain chains surrounding the Adriatic basin further increased the wind speed and determined the highest ever recorded storm surge along the Venetian coast. This study shows that present models would be able to produce a reasonably accurate simulation of the meteorological event (surface pressure, wind and precipitation fields, and storm surge level). The exceptional intensity of the event is not suggested by single parameters such as the sea level pressure minimum, the wind speed or the total accumulated precipitation. In fact, the precipitation was extreme only in some locations and the pressure minimum was not particularly deep. Moreover, the prediction of the damages produced by the river run-off and landslides would have required other informations concerning soil condition, snow coverage, and storage of water reservoirs before the event. This indicates that an integrated approach is required for assessing the probability of such damages both on a weather forecast and on a climate change perspective

The effect of the boundary conditions on the simulation of the 4 November 1966 storm over Italy

This study analyses the extreme event which took place on 4 November 1966, when a storm produced intense and persistent precipitation over northern and central Italy and an extreme surge in the northern Adriatic Sea, causing casualties and huge damages. Numerical simulations with a regional atmospheric model have been performed to reconstruct the phenomenology of the event. Results have been compared with observations. This study shows that the choice of the global fields for initial and boundary conditions is crucial for the quality of the reconstruction. The simulation is reasonably accurate if they are extracted from the NCEP re-analysis, while it is not satisfactory if ERA-40 data are used, though fields have a higher resolution in the ERA-40 than in the NCEP set of data. The internal physics of the model plays a smaller role in the reproduction of the dynamics of the event

Quando la ricerca da pubblica si fa privata : innovazioni organizzative in un caso di studio

Lo studio dell'innovazione \ue8 un'area di ricerca in rapida crescita degli studi organizzativi. Tra i diversi punti di attenzione, la distinzione tra organizzazioni pubbliche e private ha rappresentato per lungo tempo uno dei temi maggiormente discussi. All'interno di questo ambito di studio, questo contributo si pone l'obiettivo di comprendere se la trasformazione di un istituto di ricerca da ente pubblico a fondazione privata costituisca di per s\ue9 un'innovazione organizzativa. Gli autori presentano uno studio di caso in cui vengono esplorate le dinamiche di trasformazione a partire da tre specifiche, ma interdipendenti, angolazioni: i processi di governance; l'introduzione del primo contratto collettivo di lavoro privato della ricerca; le procedure amministrative e contabili. L'ultima parte \ue8 dedicata a rispondere in modo complessivo alla domanda di ricerca alla base di questo studio

A 400 Hz, 100 kVA, digitally controlled UPS for airport installations

Abstract -The paper describes analysis, design and prototyping in reduced scale of a digitally controlled inverter for uninterruptible power supply (UPS) applications. The converter is rated for 100 kVA nominal power and 400 Hz, three-phase, 220 V sinusoidal output voltage. The final equipment is meant to be installed in airport docks and used as the aircraft's electrical power supply during refuelling and loading operations. It will be manufactured with different power ratings ranging from 30 to 300 kVA. The power converter and digital control circuits are devised to provide rated voltage and frequency with a fairly low output impedance, so as to keep the voltage total harmonic distortion (THD) small even in the presence of highly distorting loads. Simulation results for the rated converter and experimental results from a scaled (5 kVA) prototype are given, which illustrate the expected converter performance