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The use of finite-element-method (FEM) simulation in electrical machine optimal design is affected by two main problems: the computation time in FEM simulations and the large number of parameters of the electrical machine. Here, we propose a surrogate model to use with electrical machines, based on statistical multiple correlation coefficients (R2) analysis and moving least squares (MLS) approximation. In the context of an optimization process, which needs a large number of evaluations strongly depending on the number of parameters, the computation effort is small compared to the time that can be saved. We validate this method by applying it to the optimal design of a synchronous machine. The results show that the torque per weight ratio improved by about 13% in comparison with that obtained by classical optimization methods. Index Terms--Moving least squares approximation, optimization, permanent-magnet synchronous motor, surrogate model.

The aim of this work is to assess the influence of a magnetic sample on the applied magnetic field inside the air gap of a magnetic circuit. Different magnetic sources including an electromagnet, a permanent magnet in a soft ferromagnetic toroidal yoke, as well as 2D and 3D Halbach cylinders are considered, using a numerical model. Gadolinium is chosen as magnetic material for the sample, due to its strong magnetocaloric properties and its wide use in magnetic refrigeration prototypes. We find that using uniform theoretical demagnetizing factors for cylinders or spheres results in a deviation of less than 2% in the calculation of internal magnetic fields at temperatures above the Curie point of gadolinium. Below the Curie point, a stronger magnetization of the cylinders and spheres leads to a larger deviation which can reach 8% when using uniform demagnetizing factors for internal magnetic field calculations. [ABSTRACT FROM AUTHOR]

This paper deals with the online fault diagnosis of polymer electrolyte membrane fuel cell (PEMFC) stack. In the proposed approach, support vector machine (SVM) and a fluidic model are correlated to realize the diagnosis of the faults on water management. With the help of the fluidic model, health states of the stack can be identified. This procedure is then dedicated to labeling the training data, which is used to train the dimension reduction model, named Fisher discriminant analysis (FDA), and the SVM classifier. The online diagnosis can then be realized by using the trained FDA and SVM models. The proposed approach is illustrated by using the experimental data of a 20-cell PEMFC stack. The feasibility of the approach for online implementation is also affirmed. [ABSTRACT FROM AUTHOR]

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Epileptic encephalopathies with continuous spike-and-waves during sleep (CSWS) are characterized by cognitive or language impairment, and are occasionally associated with pathogenic variants of the GRIN2A gene. In these disorders, speech dysfunction could be either related to cerebral dysfunction caused by the GRIN2A deleterious variant or intense interictal epileptic activity. Here, we present a patient with apraxia of speech, clearly linked to severity of epilepsy, carrying a GRIN2A variant. A 6-year-old boy developed acute regression of expressive language following epileptic seizures, leading to complete mutism, at which time EEG revealed CSWS. MEG showed bilateral superior parietal and opercular independent CSWS onsets and PET with fluorodeoxyglucose demonstrated significant increase in relative glucose metabolism in bilateral superior parietal regions. Corticosteroids induced a regression of CSWS together with impressive improvement in speech abilities. This case supports the hypothesis of a triggering role for epileptic discharges in speech deterioration observed in children carrying a deleterious variant of GRIN2A. When classic antiepileptic drugs fail to control epileptic activity, corticosteroids should be considered. Multimodal functional neuroimaging suggests a role for opercular and superior parietal areas in acquired epileptic opercular syndrome. [Published with video sequences on www.epilepticdisorders.com].

Through a survey of more than 20 patients with a specific subgroup of autosomal recessive congenital cutis laxa (ARCL), namely ATP6V0A2-related cutis laxa, we noted that the clinical findings on three patients included pretibial pseudo-ecchymotic skin lesions very similar to those found in classical Ehlers-Danlos syndrome. The finding is apparently age-related, occurring during the second decade in two of the three patients., (© 2014 Wiley Periodicals, Inc.)

We report the case of an 18-month-old boy who presented aphasia and right hemiplegia of acute onset. The neurological deficit completely resolved after a few hours, but identical transient neurological deficits and seizures occurred during the following days. Imaging showed proximal stenosis of the medial cerebral artery and deep ischaemic lesions in the territory of this artery. Analysis of the cerebrospinal fluid showed pleocytosis and an active enteroviral infection with positive RNA detection. The evolution was consistent with transient cerebral arteriopathy of childhood as magnetic resonance angiography showed normalization of the arterial lesions. This is the first report of an enteroviral infection associated with this entity. We want to stress the importance of performing a cerebrospinal fluid analysis when an ischaemic stroke of unclear aetiology occurs in a child.