96 research outputs found
Experimental Quantum Communication with GNSS satellites
No full textQuantum Communication (QC) is referred as all those protocols that deal with the faithful transportation of quantum states. The huge technological progress in the manipulation of the single quantum particles has led to the experimental tests of some of the most intriguing features of Quantum Mechanics (QM). The gedankenexperiments that were formulated by the fathers of QM in the last century, have become real. In the words of Schrödinger: “... we never experiment with just one electron or atom or (small) molecule.” This is no longer true. We can do experiments involving single atoms or molecules
and even single photons, and thus it becomes possible to demonstrate that the “ridiculous consequences” alluded to by Schrödinger are, in fact, quite real. The possibility of preparing, manipulating and detecting single photons has paved the way for the field of QC . Many interesting applications related to the security of communication start taking shape, of which the most promising is the Quantum Key Distribution ( QKD ). The crucial step towards the establishment of these quantum technologies is the extension of the communication channel up to the possibility of connecting any two points around the
Earth. To this aim, two main strategies are being pursued: the development of quantum repeaters in order to interconnect several fiber-based channels, each of which have limited extension due to the inherent losses of the fiber, and the progress of satellite-to-ground and satellite-to-satellite links that take advantage of the lower losses of the free-space channel. This thesis collects my research under the supervision of Prof. Giuseppe Vallone and Prof. Paolo Villoresi on a set of topics in the quantum communication science, the main objective being the extension of the satellite-to-ground channel towards MEO and its applications on the fundamental tests of QM . Particular attention have also been dedicated to the applications of weak measurements
A fuzzy logic-based control algorithm for the recharge/v2g of a nine-phase integrated on-board battery charger
No full textEnergy demand associated with the ever-increasing penetration of electric vehicles on worldwide roads is set to rise exponentially in the coming years. The fact that more and more vehicles will be connected to the electricity network will offer greater advantages to the network operators, as the presence of an on-board battery of discrete capacity will be able to support a whole series of ancillary services or smart energy management. To allow this, the vehicle must be equipped with a bidirectional full power charger, which will allow not only recharging but also the supply of energy to the network, playing an active role as a distributed energy resource. To manage recharge and vehicle-to-grid (V2G) operations, the charger has to be more complex and has to require a fast and effective control structure. In this work, we present a control strategy for an integrated on-board battery charger with a nine-phase electric machine. The control scheme integrates a fuzzy logic controller within a voltage-oriented control strategy. The control has been implemented and simulated in Simulink. The results show how the voltage on the DC-bus is controlled to the reference value by the fuzzy controller and how the CC/CV charging mode of the battery is possible, using different charging/discharging current levels. This allows both three-phase fast charge and V2G operations with fast control response time, without causing relevant distortion grid-side (Total Harmonic Distortion is maintained around 3%), even in the presence of imbalances of the machine, and with very low ripple stress on the battery current/voltage
A Fuzzy Control for a Nine-Phase Integrated On-Board Battery Charger
No full textRecharging faster and faster while making the vehicle less heavy and expensive is an increasingly stimulating challenge for the automotive industry. With regard to AC charging systems, which require appropriate energy conversion structures to be installed on board, the charging speed is directly proportional to the size of the mounted charger. A possible solution that allows eliminating the installed charger and using the same powertrains components both in charging and propulsion mode is the integrated on-board battery charger. In this paper we propose a recharging control algorithm for an electric vehicle's (EV) powertrain based on a nine-phase machine with a nine-phase inverter/rectifier and used as an integrated charger. The proposed algorithm combines the voltage oriented control with both fuzzy logic and adaptive hysteresis band control. Both charging mode (single-phase or three-phase) an vehicle-to-grid (V2G) are achievable at unity power factor grid side and without torque production by the machine
Experimental demonstration of sequential quantum random access codes
No full textA random access code (RAC) is a strategy to encode a message into a shorter one in a way that any bit of the original can still be recovered with nontrivial probability. Encoding with quantum bits rather than classical ones can improve this probability but has an important limitation: Due to the disturbance caused by standard quantum measurements, qubits cannot be used more than once. However, as recently shown by Mohan, Tavakoli, and Brunner [New J. Phys. 21, 083034 (2019)NJOPFM1367-263010.1088/1367-2630/ab3773], weak measurements can alleviate this problem, allowing two sequential decoders to perform better than with the best classical RAC. We use single photons to experimentally show that these weak measurements are feasible and nonclassical success probabilities are achievable by two decoders. We prove this for different values of the measurement strength and use our experimental results to put tight bounds on them, certifying the accuracy of our setting. This proves the feasibility of using sequential quantum RACs for quantum information tasks, such as the self-testing of untrusted devices
Driver Assistance System for Trams: Smart Tram in Smart Cities
No full textMobility in smart cities is also becoming smart, promoting on the one hand transport modes based on zero emission electrical technologies and on the other providing vehicles with technological solutions that support the drivers in driving operations. In the cities, more and more cars today are equipped with autonomous driving systems, based on Sensor Fusion Perception platforms, which aim to improve road safety and reduce accidents, to halve accident deaths in the shortest possible time. On the other hand, the sustainability objectives also shift to increasingly intense use of public transport with zero emissions, such as that offered by trams. Trams, unlike the other rail transport systems, use the same road infrastructure as cars, motorbikes, bikes, and pedestrians and will soon find themselves interacting with vehicles with increasingly higher autonomous driving levels. It is clear, therefore, that even for trams, the time is ripe to accommodate driving support systems. In this document, an overview is provided of the potential for the diffusion of advanced driver assistance systems by the automotive sector, in order to then evaluate their porting to trams, with the ultimate goal of increasing their level of safety and automation
Rate of complications due to neuromuscular scoliosis spine surgery in a 30-years consecutive series
No full textPURPOSE:
The aim of this study was to evaluate the rate of intraoperative and postoperative complications in a large series of patients affected by neuromuscular scoliosis.
METHODS:
It was a monocentric retrospective study. In this study have been considered complications those events that significantly affected the course of treatment, such as getting the hospital stay longer, or requiring a subsequent surgical procedure, or corrupting the final result of the treatment.
RESULTS:
Of the 358 patients affected by neuromuscular scoliosis treated from January 1985 to December 2010, 185 that met the inclusion criteria were included in the study. There were recorded 66 complications in 55/185 patients. Of that 66 complications, 54 complications occurred in 46/120 patients with Luque's instrumentation, while only 12 complications occurred in 9/65 patients with hybrid instrumentation and this difference was statistically significant (p < 0.05); 11/126 patients with pelvic fixation and 5/59 without pelvic fixation, as well as 45/156 patients treated by posterior approach alone and 10/29 patient that underwent combined anterior-posterior approach suffered complications but both this did not result in a statistical significant difference (p > 0.05).
CONCLUSIONS:
The surgical treatment in neuromuscular scoliosis is burdened by a large number of complications. An accurate knowledge of possible complications is mandatory to prepare strategies due to prevent adverse events. A difference in definitions could completely change results in good or bad as well as in our same series the adverse events amounted at almost 30% of cases, but complications that due to complete failure would amount at 9.19% of patients.
KEYWORDS:
Complications; Neuromuscular scoliosis; Scoliosis; Scoliosis surgery
PMID: 28314995 DOI: 10.1007/s00586-017-5034-6
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Arthroscopic Treatment of 2 Consecutive Cases of Dysplasia Epiphysealis Hemimelica of the Ankle: A 5-Year Follow-Up Report
No full textThe dysplasia epiphysealis hemimelica (DEH) is a rare disease of unknown etiology consisting in an abnormal osteocartilaginous growth at the epiphysis, usually hemimelic with histological findings similar to benign osteochondroma. In this case series, we described the results of the arthroscopic treatment of 2 consecutive cases of intra-articular ankle localization of DEH in 2 patients aged 9 and 10 years. The good result obtained, persistent at the 5-year follow-up, leads us to consider the arthroscopic approach as a reliable treatment in patient affected by intra-articular ankle DEH
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