105 research outputs found
Foundations of Quantum Federated Learning Over Classical and Quantum Networks
Quantum federated learning (QFL) is a novel framework that integrates the
advantages of classical federated learning (FL) with the computational power of
quantum technologies. This includes quantum computing and quantum machine
learning (QML), enabling QFL to handle high-dimensional complex data. QFL can
be deployed over both classical and quantum communication networks in order to
benefit from information-theoretic security levels surpassing traditional FL
frameworks. In this paper, we provide the first comprehensive investigation of
the challenges and opportunities of QFL. We particularly examine the key
components of QFL and identify the unique challenges that arise when deploying
it over both classical and quantum networks. We then develop novel solutions
and articulate promising research directions that can help address the
identified challenges. We also provide actionable recommendations to advance
the practical realization of QFL.Comment: 7 pages, 2 figures, 2 table
H∞ based control of a DC/DC buck converter feeding a constant power load in uncertain DC microgrid system
DC microgrids are gaining more and more popularity and are becoming a more viable alternative to AC microgrids (MGs) due to their advantages in terms of simpler power converter stages, flexible control algorithms and the absence of synchronization and reactive power. However, DC-MGs are prone to instability issues associated with the presence of nonlinear loads such as constant power loads (CPL) known by their incremental negative impedance (INI), which may lead to voltage collapse of the main DC Bus. In this paper, -based controller of a source side buck converter is designed to avoid the instability issues caused by the load-side converter acting as a CPL. Besides, the proposed controller allows a perfect rejection of all perturbations that may arise from parameter variations, input voltage and CPL current fluctuations. The design process of H-based controller is based on the Golver Doyle Optimization Algorithm (GDOA), which requires an augmented system extracted from the small-signal model of the DC/DC converter including the mathematical model of parameter variations and overall external perturbations. The based controller involves the use of weight functions in order to get the desired performances. The proposed controller is easy to implement and lead to reducing the implementation cost and avoid the use of current measurement that may have some disadvantages. The derived controller is validated by simulation performed in Psim software and experimental setup
042: Real life dual antiplatelet therapy after NSTE-ACS in a Tunisian population: is there a need for 12 months of treatment?
AimEven if the recommended duration for dual antiplatelet therapy (DAT) after non ST elevation acute coronary syndromes (NSTE-ACS) is 12 months, evidence concerning the benefit of clopidogrel adjunction especially beyond 3 months remains poor. The aim of the study was to assess the effective clopidogrel intake and the incidence of a composite endpoint including all causes death and non fatal myocardial infarction in a Tunisian population after NSTE-ACS.MethodsWe included patients admitted for NSTE-ACS in our department between January 2010 and August 2011 for whom long term evaluation was possible. In-hospital deaths were excluded (including post operative deaths). By telephone follow up, we evaluated the effective DAT duration and the occurrence of all causes death and non-fatal myocardial infarction.ResultsOne hundred thirty patients were included. Mean (SD) follow up was 261 (99) days. DAT was effectively observed during 94(103 days (extremes ranging from 0 to 360 days). Angioplasty was performed in 51.5%, coronary artery bypass graft in 8.4% and medical therapy was considered in 40.1%. In 35 (26.9%) patients, aspirin was the only antiplatelet therapy taken after discharge although DAT was prescribed; 46.9% of the patients took the DAT for more than 3 months, and 23.1% for more than 6 months. The composite endpoint occurred in 6 (4.6%) patients: 2 deaths (both of cardiac causes) and 4 myocardial infarctions. Three of them were under DAT, and the 3 others remained event free during 7, 240 and 270 days after clopidogrel withdrawal. These findings suggest that DAT does not protect against death or myocardial infarction. The rebound phenomenon after clopidogrel withdrawal isn’t patent in our population.ConclusionIn the Tunisian context, DAT observance is poor after NSTE-ACS. Death and non fatal myocardial infarction don’t seem to be reduced by DAT and the rebound phenomenon after clopidogrel withdrawal isn’t patent. This may be in part attributed to the small sample of population and the predominantly low risk (as assessed by TIMI risk score), but larger studies are needed to strengthen the evidence for DAT after NSTE-ACS
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