• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.95-100
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• 2007

The traction motor for High Speed Train is being required reliability and stability for high-speed operation. And also required low noise level, high performance, compact size owing to the space and weight limitation for attaching to train, etc. As a result of requiring the low noise level and high power capacity, it is adopted forced-air-ventilation insead of self-ventilation that is generally used on electric multiple unit. Traction motor is cooled by cooling air through the air-ventilation hole. When the traction motor is operated with forced-air-ventilation, there is some abnormal noise in the specific RPM. This paper is dealing with the method to reduce the resonance phenomena by adopting the rotor blade.

• 대한전기학회논문지
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• 제38권4호
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• pp.269-278
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• 1989

When the induction motor is operated by CSI, the commutation capacitance in the CSI circuit is increased according to the increase of large capacitor system. The output voltage spikes are generated at the moment of charge and discharge of the commutation capacitor. Also, since output current comprise a great number of harmonics, torque ripples of the motor are generated, having bad effects on the motor. In this study, by adopting the 18-phase multiple high Frequency Current Source Inverter (HFCSI), torque ripples generated by the voltage spikes are mostly eliminated except the 17th and 19th harmonics. To reduce the voltage spikes comprised in the output voltage, particularly, the methods of eliminating the cause of bad effect upon the motor are proposed in this paper. In the proposed method, by using additional voltage Clamping Curcuit (VCC), it is possible to select the values of commutation capacitor energy loss in commutating, the commutating capacitor, and the capacitor in the clamping circuit.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.36-38
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• 1995

AC servo motors are widely used for various mechatronic devices such as FA, OA and robot machines. To obtain more accurate simulation results, a method of analysis for AC servo motor is described using transient magnetic formulation coupled with external circuit equation of the motor. The external circuit of the motor to be analyzed is described using FLUX2D program and linked to multiple finite element regions. The simulation results show that transient magnetic analysis coupled with extenal circuit has more accurate than those results from magnetostatic.

• Journal of Power Electronics
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• 제16권5호
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• pp.1781-1790
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• 2016

This study focuses on the coordination control problem of multiple electrical excited synchronous motor systems. A robust coordination controller is designed on the basis of cross coupling and an interval matrix. The proposed control strategy can deal with load uncertainty. In addition, the proposed control strategy is applied to a high-power metal-rolling system. Simulation and experiment results demonstrate that the proposed control strategy achieves good dynamic and static performance. It also shows better coordination performance than traditional proportional-integral controllers.

• International Journal of Automotive Technology
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• 제7권2호
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• pp.129-137
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• 2006

The representative interactive flamelet(RIF) concept has been applied to numerically simulate the combustion processes and pollutant formation in the HSDI diesel engine. In order to account for the spatial inhomogeneity of the scalar dissipation rate, the eulerian particle flamelet model using the multiple flamelets has been employed. The vaporization effects on turbulence-chemistry interaction are included in the present RIF procedure. the results of numerical modeling using the rif concept are compared with experimental data and with numerical results of the widely-used ad-hoc combustion model. Numerical results indicate that the rif approach including the vaporization effect on turbulent spray combustion process successfully predicts the ignition delay characteristics as well as the pollutant formation in the HSDI diesel engines.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권7호
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• pp.323-330
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• 2001

Niching method enables the genetic algorithm(GA) to be applied to the problems that require the location of multiple solutions in the search space, but these methods have fatal disadvantages. The main disadvantage is that the method requires too much calculation of object function. In this paper, a niching method using restricted competition selection(RCS) combined with a pattern search method(PSM) is proposed to identify multiple niches more efficiently and fast in a multimodal domain. The validity of the proposed method is verified by the simulation of test functions and the optimal design of an torque motor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.15-17
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• 1994

As VCB has many advantages which is an excellent interruption capability, compact structure, easy maintenance and light weight, it has been widely used as a load breaker. But steep-fronted surge voltage due to high frequency extinguishing capability in switching has been occurred. If it impinges into induction motor, it acts on the electrical stress, and causes to deteriorate winding insulation. In this research, in order to protect motor insulation from the steep-fronted reignition surge, the occurring condition, the cause of the reignition surge and the influence of circuit parameters which have been an effect on the occurrence of reignition and multiple reignition surge has been also analyzed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1097-1099
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• 2004

This paper deals with the optimal design of a slotless type of permanent magnet linear synchronous motor (PMLSM). Response surface methodology, one of the optimization methods, is used to consider multiple response of the PMLSM. That is, it is applied to obtain more average thrust and less thrust ripple than prototype PMLSM. To analyze quickly, characteristic analysis of the PMLSM is performed by space harmonic method and final results of optimized PMLSM are compare with those of prototype PMLSM through finite element analysis.

• Annals of Clinical Neurophysiology
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• 제6권1호
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• pp.52-56
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• 2004

Acute motor axonal neuropathy (AMAN) is a subtype of Guillain-Barre syndrome and characterized by selective involvement of motor fibers. Acute disseminated encephalomyelitis (ADEM) is a demyelinating disease of central nervous system. The coincidence of central and peripheral nervous system involvement has been reported rarely. We described a 37-year-old male patient presented with fever and altered consciousness. The examination of cerebrospinal fluid and brain magnetic resonance imaging was compatible with acute disseminated encephalomyelitis. Several days after admissionb his mentality was improved but quadriparesis, multiple cranial neuropathies, and areflexia were detected. Electrophysiologic studies suggested axonal form of motor dominant polyneuropathy. We report a case of acute motor axonal neuropathy combined with ADEM. We consider that this case is an example of simultaneous immunologic process to the common pathogenic epitope of central nervous system and peripheral nervous system.

• 한국공작기계학회논문집
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• 제13권4호
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• pp.56-63
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• 2004

Recently technology resulted in highly efficient and multiple-functional electric appliances considering environmental problems. One of the environmental problems is noise of a product in respect to its function. A vacuum cleaner is an essential electric appliance in our daily lives. However, severe noise resulted from high motor speed for improving the function of the appliance is a nuisance for the user. This noise is caused by vibration from various parts of the appliance and fluid noise during a series of intake and exhaust processes while rotating the impeller connected to the axle at a high speed of the fan motor inside the vacuum cleaner rotating around 30,000-35,000rpm. Despite the fact that many researchers conducted studies on reducing the noise level of the fan motor in a vacuum cleaner, only few studies have been conducted considering both the theoretical and experimental aspects using fluid analysis by measuring vibration and noise. Moreover, there has not been a study that accurately compared major noise data obtained considering both of the aspects. In this study, both aspects were considered by considering the following experimental and theoretical methods to verify the major causes of noise from the fan motor in a vacuum cleaner.