• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.2 s.314
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• pp.24-31
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• 2007

This paper presents self tuning PI(STPI) controller of IPMSM drive using neural network. In general, PI controller in computer numerically controlled machine process fixed gain. They may perform well under some operating conditions, but not all. To increase the robustness of fixed gain PI controller, STPI controller proposes a new method based neural network. STPI controller is developed to minimize overshoot, rise time and settling time following sudden parameter changes such as speed, load torque and inertia. Also, this paper is proposed speed control of IPMSM using neural network and estimation of speed using artificial neural network(ANN) controller. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The results on a speed controller of IPMSM are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.

• Clinics in Shoulder and Elbow
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• v.11 no.2
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• pp.131-136
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• 2008

Purpose: Parsonage-Turner syndrome is a rare disorder with sudden onset of severe pain around the shoulder girdle, followed by weakness of the shoulder muscles. The purpose of the current study was to describe the clinical features associated with this condition and to review the literature. Materials and methods: A retrospective study of the Parsonage-Turner syndrome was carried out for 6 patients seen from December 2005 to July 2008. The clinical and radiographic data was collected by medical records and telephone interviews. Five patients were males and one was female with ages ranging between 20-68 years (mean, 43.5). The mean follow-up period was 19.1 months (range, 14-27 months). Results: The intense pain around shoulder continued for 1 day to 3 weeks and decreased spontaneously at a mean of 3.3 weeks (range, 2-5 weeks) after onset of pain. Weakness in the involved muscles had developed at a mean of four weeks (range, 2-7 weeks). At the end of follow-up, five patients had an improvement of their strength and one patient had regained full strength. Electromyography was the most helpful in diagnosis. Conclusion: Parsonage-Turner syndrome is a self-limited disorder with a good outcome. Understanding of the course will assist in the diagnosis and treatment.

• Archives of design research
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• v.11 no.3
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• pp.219-228
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• 1998

As automobile drivers' desires become ever diversified with the spreading phenomenon of 'characteristic automobile decorations', it is feared that the design quality may be deteriorated, while the safety be retarded in terms of performance and function. In Korea, the 'Dress-up tuning' becomes the source of the social criticism because of lack of relevant codes and professional tuning services, while automobile drivers are excessively having their automobiles overdressed ignoring the overall aesthetic aspect and functions. Under such a circumstance, this study was aimed at reviewing the practices and dress-up accessories by each automobile part of those foreign automobile makers and professional tuners who have introduced the concept of 'customizing' and developed dress-up accessories and various tuning parts only to satisfy their customers' tuning needs. It is anticipated that automobile styling would tend more to pursue a 'coordination' featuring ordinary consumers' individualistic senses, while customers' needs reflecting their life styles be more refined. Meanwhile, Korean automobile consumers have accommodated the product designs : presented within the producers' frameworks, but they are expected to pursue the design values varying according to changing structures of production, society and industry as well as the resultant design activities. In all, makers and designers are requested to be aware of such changing environment structures and thereby, explore other alternatives, or reflect seriously on the socio-cultural implications inherent in the products, namely on the production and consumption of people's favorites.