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Hamdi Echeikh Ramzi Trabelsi Atif Iqbal Med Faouzi Mimouni 《Journal of The Franklin Institute》2018,355(5):2112-2141
High performance multiphase motor drive requires precise knowledge of the state quantities and the machine parameters. Access to these state quantities is through measurement using sensors whose accuracy is paramount to achieve the performance level required by industrial applications. However, the problems of the parameters variations, inaccessibility to the measurement of some states, no-observability of the machine in some regions, the cost of the sensors and their lack of precision, make this very difficult task. To address these problems, it is necessary to resort to soft sensors through the design of observers and estimators. In multiphase induction motor drive, the observation problem arises especially for rotor flux that is not accessible for measurement. About the parameters variations, the rotor resistance and the stator resistance are the most critical parameters of the machine because their influence is crucial for the control and observation. The change in the resistances can be as large as 40–50% of the rated value, which may affect the control adversely. This paper develops a new structure of an adaptive sliding mode observer based on an online estimation of the rotor resistance value in order to avoid the effect of its variation in the rotor flux oriented control. The results show convergent (the errors in the transient and steady states are 5% and 1%, respectively) behavior of the drive using the proposed control scheme for large rotor resistance variation under loaded condition. The stability of the drive is proved using Lyapunov criteria. The simulation results are validated using real time implementation. 相似文献
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针对多种噪声的干扰,采用自适应平滑技术、自适应滤波技术、普通数字滤波器和一种用于消除50Hz市电干扰的方法在Compaq 286e微机上对人体正中神经束内诱发的单一传入电位的波形特征进行处理,发现自适应滤波及快速算法可以很好地消除市电干扰,但电位波形发生严重畸变而自适应平滑的效果比较理想;后者适应范围较广,对降低神经电位的各种干扰有明显效果;快速算法可用于生物信号的实时处理. 相似文献
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卡托普利是第一个用于临床的口服血管紧张素转化酶(ACE)抑制药.近10余年来此类药物发展迅速,临床应用的已逾十种.它们通过抑制ACE的活性,使血管紧张素Ⅰ不能转化为血管紧张素Ⅱ而降压.用以治疗高血压病有一定效果,预测或可望与β-受体阻滞剂、噻嗪类利尿剂等一样成为一线降压药.本类药物与利尿剂、钙拮抗剂等合用可增强降压疗效.其次当心衰病人用强心甙和利尿剂效果不佳时,加用本类药亦有增效作用.本文还对新发展的依那普利、赖诺普利、雷米普利、贝那普利、西拉普利、哌林多普利、喹那普利、磷诺普利和西瓦那普利等九种ACEI抑制药从药动学、临床应用及用法剂量等方面作了简要叙述。 相似文献
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Amine Hadj Taieb Manel Hammami Slah Msahli Faouzi Sakli 《The International Journal of Art & Design Education》2010,29(3):313-320
Human health is affected by pollution caused by toxic chemical substances, particularly vulnerable groups like children. So how can we make things better for people and for the environment through the textile products we design? By thinking about the environment when designing, choosing and using environmental‐friendly technology, we can play an important role in building a better world for the future. If we are going to live in a sustainable way, the technology and materials that we use have to be sustainable. This article provides an insight into how textile product design can provide a better future. It describes the design of ecological textile messages for sensitising and educating children. In the long term, such design may help towards ensuring a better quality of life for everyone, now and in the future. In this survey, the design of the sensitising messages was done using ecological techniques and raw materials to accentuate the message and took into account the intellectual and psychological level of children. All of the raw materials, process and plant dyes used were analysed from an environmental perspective. 相似文献
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Professor Marie Parker-Jenkins Dr. Dimitra Hartas Med Ph.D. C. Psych 《Education 3-13》2013,41(2):39-42
In this article, we explore distinctions between creative practice and a practice which fosters creativity, drawing on case study data from an English nursery and a first school. We suggest that, in practice, these distinctions are very blurred. 相似文献
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