381 research outputs found

    Design of a high-torque machine with two integrated motors axes reducing the electric vehicle consumption

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    The motorization of electric vehicle needs to work at a constant power on a wide range of speed. In order to be able to satisfy these requirements, we describe in this paper a solution, which consists in modifying of a simple structure of a permanent magnet motor by a double rotor structure integrating two motor axes into the same machine. This article describes, then, a design methodology of a permanent magnet motor with double rotor, radial flux, and strong starting torque for electric vehicles. This work consists on the analytical dimensioning of the motor by taking into account several operation constraints followed by a modelling by the finite elements method. This study is followed by the comparison between this motor and a motor with one rotor. A global model of the motor- converter is developed for the purpose to answer several optimisation problem

    Effect of verbal instruction on motor learning ability of anaerobic and explosive exercises in physical education university students

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    This study investigated the effect of motor learning with informational feedback into response to anaerobic exercises with and without motor learning tasks in handball physical education university students. Participants were randomly divided into two groups: experimental group (EG, n = 10) and control group (CG, n = 10). Measurements of T-half test, 15-m and 30-m sprints, and ZIG-ZAG test were assessed in both groups before (T1), between (T2) a 4-week intervention program, and after (T3) an 8-week intervention program, which included agility and speed teaching with (EG) or without (CG) informational feedback (i.e., verbal instruction). The test-retest reliability for all tests was excellent, and the ICC ranged from 0.76 (ZIG-ZAG test) to 0.99 (Agility T test). The interday measurement error was clearly below 1% in all tests (CV range: 0.2–0.8). Time effects for the Agility T test (p = 0.012, η2p = 0.245) and the 15-m sprint (p = 0.035, η2p = 0.190) were found. For the Agility T test, a total interaction effect (p = 0.001, η2p = 0.380) and a partial interaction effect were calculated between T2 and T3 (p < 0.001, η2p = 0.603). A large effect size (d = 0.87) was observed in the EG from T2 to T3. The second relevant (d ≄ 0.5) effect size was calculated for the parameter sprint 30 m. The CG showed a significant sprint performance reduction from T2 to T3 (d = −0.60; parameter: sprint 30 m). All other effect sizes were less than 0.44. The ZIG-ZAG test revealed the largest main and partial effect sizes for all parameters. The EG showed the largest improvement (d = 2.00) between T2 and T3. The results demonstrate that motor learning with informational feedback improves performances of Agility T test, sprint, and ZIG-ZAG performance. It appears that a well-formulated verbal instruction may induce performance enhancement in young trainees in educational environment.The publication of this article was funded by the Qatar National Library. We thank Professor Mohamed Souhaiel Chelly [Research Unit (UR17JS01) “Sport Performance, Health & Society,” Higher Institute of Sport and Physical Education of Ksar Said, University of “La Manouba,” Tunisia] for his valuable experimental help

    Myasthenie - spondylarthropathies: association fortuite ? A propos d’un cas et revue de la littĂ©rature

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    Propos Nous rapportons le cas d’un patient atteint d’une myasthĂ©nie associĂ©e Ă  une spondylarthropathie. Cette observation est originale de part sa raretĂ©, six cas seulement on Ă©tĂ© rapportĂ©s dans la littĂ©rature et le problĂšme que pose cette association : est ce qu’elle est fortuite ou impliquerait-elle d’autres facteurs gĂ©nĂ©tiques qui restent Ă  prouver ?Observation Monsieur J.H. ĂągĂ© de 32 ans, aux antĂ©cĂ©dents de myasthĂ©nie depuis 2002, Ă©tait hospitalisĂ© en avril 2004 pour polyarthrite chronique bilatĂ©rale et asymĂ©trique Ă©voluant depuis un an, touchant le poignet gauche, les inter phalangiennes proximales des 3Ăšme et 5Ăšme doigts droits et le genou droit associĂ©es Ă  des talalgiesbilatĂ©rales et une douleur des articulations sacro-iliaques. La biologie montrait un syndrome inflammatoire modĂ©rĂ©, des facteurs rhumatoĂŻdes faiblement positifs et un typage HLA B7 et B17. Le bilan radiologiquemontrait une arthrite des mains, une enthĂ©site calcanĂ©enne et permettait de suspecter une sacro-iliite bilatĂ©rale qui Ă©tait confirmĂ©e par un scanner. L’évolution Ă©tait bonne sous anti- inflammatoires nonstĂ©roĂŻdiens pendant 6 mois. Il consulte en janvier 2006 pour le mĂȘme tableau associĂ© Ă  une sĂšcheresse buccale et oculaire. Le bilan trouvait une VS Ă  20, des facteurs rhumatoĂŻdes faiblement positifs mais desAAN positifs Ă  un taux 1/160 homogĂšnes avec des anti SSA. Les radiographies standard montraient une carpite stade II gauche. L’examen ophtalmologique a confirmĂ© le syndrome sec oculaire. La biopsie des glandes salivaires accessoires a montrĂ© un syndrome de Gougerot Sjögren grade 2 de Shisholm

    MIMO Modeling Approach for a Small Photovoltaic Reverse Osmosis Desalination System

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    The most widely used desalination processes are based on membrane separation via reverse osmosis (RO) which has become an important process for desalting seawater and cleaning brackish water. The use of these processes requires an efficient control system. Consequently, it is necessary to establish a dynamic model of the system with experimental validation. This paper deals with a new modelling approach of a small photovoltaic reverse osmosis (PV-RO) desalination unit. The proposed model considers the unit as a Multi Input Multi Output (MIMO) process. The relations between the output variables and the input variables are given by the use of empirical transfer matrix. A state model of the unit is also given. Some experimental results are presented to validate the proposed model. As result, the obtained unit model can be easily used for a process control loop implementation in order to assure an optimum operating condition and to reduce the water product cost

    The application of ground-based and satellite remote sensing for estimation of bio-physiological parameters of wheat grown under different water regimes

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    Remote sensing technologies have been widely studied for the estimation of crop biometric and physiological parameters. The number of sensors and data acquisition methods have been increasing, and their evaluation is becoming a necessity. The aim of this study was to assess the performance of two remote sensing data for describing the variations of biometric and physiological parameters of durum wheat grown under different water regimes (rainfed, 50% and 100% of irrigation requirements). The experimentation was carried out in Policoro (Southern Italy) for two growing seasons. The Landsat 8 and Sentinel-2 images and radiometric ground-based data were acquired regularly during the growing season with plant biometric (leaf area index and dry aboveground biomass) and physiological (stomatal conductance, net assimilation, and transpiration rate) parameters. Water deficit index was closely related to plant water status and crop physiological parameters. The enhanced vegetation index showed slightly better performance than the normalized difference vegetation index when plotted against the leaf area index with R2 = 0.73. The overall results indicated that the ground-based vegetation indices were in good agreement with the satellite-based indices. The main constraint for effective application of satellite-based indices remains the presence of clouds during the acquisition time, which is particularly relevant for winter-spring crops. Therefore, the integration of remote sensing and field data might be needed to optimize plant response under specific growing conditions and to enhance agricultural production

    Le cholestĂ©atome de l’oreille moyenne

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    Le cholestĂ©atome se prĂ©sente comme une pseudotumeur inflammatoire de type Ă©pidermique envahissant les cavitĂ©s de l’oreille moyenne et prĂ©sentant un double potentiel de desquamation en surface et de lyse osseuse en profondeur. C’est une forme particuliĂšrement agressive d’otite moyenne chronique dont le traitement est exclusivement chirurgical. Le but de cet article est de prĂ©senter une mise au point sur la prise en charge de cette pathologie en intĂ©grant les principales avancĂ©es rĂ©centes qui sont reprĂ©sentĂ©es par les progrĂšs de l’imagerie moderne qui permet de mieux cerner les extensions du cholestĂ©atome en prĂ©opĂ©ratoire et qui permet Ă©galement un suivi moins invasif en postopĂ©ratoire, l’utilisation plus rĂ©glĂ©e et mieux codifiĂ©e du cartilage et l’introduction de l’otoendoscopie.Cholesteatoma appears as an inflammatory pseudo-tumor of epidermic type invading the cavities of the middle ear and presenting a double potential of desquamation and of osteolysis. It is a particularly aggressive type of chronic otitis and surgery is its exclusive treatment. The aim of this article is to present the state of the art of disease management by integrating the main recent advances concern the progress of the modern imaging allowing more acute preoperative determination of extension of the cholesteatoma and a less invasive postoperative follow-up, the more adjusted and better codified use of the cartilage and the introduction of the otoendoscopy

    Atrésie choanale : A propos de 29 cas

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    Introduction : L’atrĂ©sie choanale est une malformation congĂ©nitale rare, dont la frĂ©quence est estimĂ©e Ă  1 cas pour 5000 Ă  8000 naissances. plusieurs hypothĂšses embryologiques ont Ă©tĂ© proposĂ©es pour expliquer son origine. Le diagnostic de cette malformation est avant tout clinique.Objectifs : analyser les caractĂ©ristiques Ă©pidĂ©mio-cliniques et  paracliniques des atrĂ©sies choanales et discuter les modalitĂ©s thĂ©rapeutiques de cette malformation.MatĂ©riel et mĂ©thodes : il s'agit d'une Ă©tude rĂ©trospective Ă  propos de 29 cas d'atrĂ©sie choanale suivis au service d'Otorhinolaryngologie de l'hĂŽpital la Rabta sur une pĂ©riode de 20 ans (1990-2009).RĂ©sultats : L'Ăąge moyen de dĂ©couverte Ă©tait de 10,6 ans (1 jour - 35 ans). Une prĂ©dominance fĂ©minine a Ă©tĂ© notĂ©e. L'atrĂ©sie Ă©tait bilatĂ©rale dans 8 cas et unilatĂ©rale dans 21 cas. Un scanner du massif facial a Ă©tĂ© rĂ©alisĂ© dans 23 cas. L'atrĂ©sie Ă©tait osseuse dans 30,4 % des cas, membraneuse dans 13 % et mixte dans 56,6 %. Concernant le  traitement, on a eu recours Ă  la divulsion dans un cas, la voie  transpalatine dans 15 cas (dont 2 aprĂ©s echec divulsion premiĂšre) etla voie endonasale dans 13 cas.  Le taux de succĂšs obtenu par la voie endoscopique endonasale est Ă©valuĂ© Ă  72,72% et par la voie transpalatine Ă  71,42%. Le taux de succĂšs passe Ă  100% aprĂšs reprise chirurgicale.Conclusion : L’atrĂ©sie choanale est une pathologie qui doit ĂȘtre dĂ©pistĂ©e Ă  la pĂ©riode nĂ©onatale. L’endoscopie nasale et le scanner ont complĂštement rĂ©volutionnĂ© les approches diagnostiques et thĂ©rapeutiques de cette pathologie. La chirurgie endonasale sous guidage endoscopique est actuellement la technique de choix.Mots clĂ©s : atrĂ©sie ; choane ; chirurgie endoscopiqu

    Pragmatic Ontology Evolution: Reconciling User Requirements and Application Performance

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    Increasingly, organizations are adopting ontologies to describe their large catalogues of items. These ontologies need to evolve regularly in response to changes in the domain and the emergence of new requirements. An important step of this process is the selection of candidate concepts to include in the new version of the ontology. This operation needs to take into account a variety of factors and in particular reconcile user requirements and application performance. Current ontology evolution methods focus either on ranking concepts according to their relevance or on preserving compatibility with existing applications. However, they do not take in consideration the impact of the ontology evolution process on the performance of computational tasks – e.g., in this work we focus on instance tagging, similarity computation, generation of recommendations, and data clustering. In this paper, we propose the Pragmatic Ontology Evolution (POE) framework, a novel approach for selecting from a group of candidates a set of concepts able to produce a new version of a given ontology that i) is consistent with the a set of user requirements (e.g., max number of concepts in the ontology), ii) is parametrised with respect to a number of dimensions (e.g., topological considerations), and iii) effectively supports relevant computational tasks. Our approach also supports users in navigating the space of possible solutions by showing how certain choices, such as limiting the number of concepts or privileging trendy concepts rather than historical ones, would reflect on the application performance. An evaluation of POE on the real-world scenario of the evolving Springer Nature taxonomy for editorial classification yielded excellent results, demonstrating a significant improvement over alternative approaches

    Les tumeurs benignes de la parotide

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    Introduction : Les tumeurs parotidiennes bĂ©nignes sont caractĂ©risĂ©es par une grande diversitĂ© histologique. Les indications thĂ©rapeutiques ne sont pas encore bien codifiĂ©es et restent un sujet de controverse.MatĂ©riel et mĂ©thodes : Nous rapportons une Ă©tude rĂ©trospective Ă  propos de 48 cas de tumeurs parotidiennes bĂ©nignes, colligĂ©s sur une pĂ©riode de 7 ans (2004-2010). Tous les patients ont bĂ©nĂ©ficiĂ© d’un examen ORL complet, d’un bilan biologique et radiologique. Le traitement Ă©tait chirurgical dans tous les cas.RĂ©sultats : L’ñge moyen Ă©tait de 46 ans et le sex-ratio 1,52. Le motif de consultation Ă©tait dans tous les cas une tumĂ©faction au niveau de la rĂ©gion parotidienne. L’échographie cervicale a confirmĂ© le siĂšge intra-parotidien dans tous les cas. L’IRM Ă©tait pratiquĂ©e chez 28 patients. Le cystadĂ©nolymphome Ă©tait Ă©voquĂ© dans 6 cas et l’adĂ©nome plĂ©omorphe dans 22 cas. Une cytoponction a Ă©tĂ© pratiquĂ©e chez 8 patients et a montrĂ© un aspect en faveur d’adĂ©nome plĂ©omorphe dans 6 cas et de cystadĂ©nolymphome dans 2 cas. Tous les patients ont Ă©tĂ© opĂ©rĂ©s sous anesthĂ©sie gĂ©nĂ©rale. La tumeur Ă©tait au dĂ©pends du lobe superficiel dans 43 cas et du lobe profond dans 5 cas. Une parotidectomie totale a Ă©tĂ© pratiquĂ©e chez les 5 patients ayant une tumeur au dĂ©pends du lobe profond. Parmi les 43 patients ayant une tumeur au dĂ©pends du lobe superficiel, une parotidectomie totale a Ă©tĂ© pratiquĂ©e chez 5 patients, une parotidectomie exofaciale chez 35 patients et une simple Ă©nuclĂ©ation tumorale dans 3 cas. L’examen anatomopathologique dĂ©finitif était concordant avec l’examen extemporanĂ© dans 100% des cas. Au total, nous avions 31 cas d’adĂ©nome plĂ©omorphe et 17 cas de cystadĂ©nolymphome. Des complications post-opĂ©ratoires Ă©taient prĂ©sentes dans 9 cas. L’évolution ultĂ©rieure a Ă©tĂ© marquĂ©e par l’absence de rĂ©cidive dans tous les cas, avec un recul moyen de 28 mois.Conclusion : Le dĂ©veloppement des techniques de l’imagerie a permis actuellement d’évoquer le diagnostic de bĂ©nignitĂ© d’une tumeur parotidienne et mĂȘme d’évoquer fortement un diagnostic anatomopathologique. Le choix de l’intervention chirurgicale est guidé par la localisation et l’étendue de la tumeur et par le type histologique.Mots-clĂ©s : tumeur bĂ©nigne, glande parotide, imagerie par rĂ©sonance magnĂ©tique, cytoponction, parotidectomie, nerf facialIntroduction: Benign parotid tumors are characterized by high histological diversity. Therapeutic indications are not well codified and remain a subject of controversy.Materials and Methods: We report a retrospective study of 48 cases of benign parotid tumors, collected over a period of 7 years (2004-2010). All patients underwent complete ENT examination, biological and radiological assessment. Treatment was surgical in all cases.Results : The mean age was 46 years and the sex ratio 1.52. Tumefaction in the parotid region was the presenting symptom in all cases. Cervical ultrasound confirmed the intra-parotid location in all cases. MRI was performed in 28 patients. Cystadenolymphoma was suggested in 6 cases and pleomorphic adenoma in 22 cases. A fine-needle aspiration was performed in 8 patients and showed pleomorphic adenoma in 6 cases and cystadenolymphoma in 2 cases. All patients were operated under general anesthesia. The tumor was at the expense of the superficial lobe in 43 cases and the deep lobe in 5 cases. A total parotidectomy was performed in 5 patients having a deep lobe tumor. Among the 43 patients having a superficial lobe tumor, a total parotidectomy was performed in 5 patients, an exofacialparotidectomy in 35 patients and a single tumor enucleation in 3 cases. The final histological examination was consistent with the frozen section in 100% of cases. In total, we had 31 cases of pleomorphic adenoma and 17 cases of cystadenolymphoma. Postoperative complications were present in 9 cases. The subsequent evolution was marked by the absence of recurrence in all cases, with a mean follow-up period of 28 months.Conclusion : The development of imaging techniques has currently allowed to suggest the diagnosis of benignity of a parotid tumor, and even to highly evoke the pathological diagnosis. The choice of surgical procedure is guided by the location and extent of the tumor and by the histological type.Keywords : benign tumor, parotid gland, magnetic resonance imaging, fine-needle aspiration, parotidectomy, facial nerv
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