• Korean Journal of Clinical Laboratory Science
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• v.48 no.1
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• pp.41-48
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• 2016

Motor evoked potential of spinal surgery is known to cause damage due to the movement path of the continuous scan operation and surgery can be performed with minimized disability after surgery. However, if it is not at all formed at the wave motion evoked potential can occur during surgery and, in some cases the size of the waveform to be measured is very small and intermittent. In this case, the surgery cannot provide information about whether there is neurological damage. Increased intensity of the wave-induced motion of the dislocation does not occur if it appears in a very small amplitude stimulus, but changing the inspection area that electrical stimulation of the waveform changes could not be found. However, stimulation of a wide area in the cerebral cortex was found to occur with a waveform in the patients who underwent examination. Through this study, we propose a useful motor evoked potential test. From November to December 2015 three spine surgery patients visited Samsung Medical Center as neurosurgery patients with omission discomfort, gait disturbance, and no symptom of strength before surgery. In spine surgery patients with motor grade weakness, when motor evoked potential waveform has not been measured, in examination of the site of electrical stimulation of the cerebral cortex from entering the C3+C5/C4+C6 or C3+C1/C4+C2 if by the activity of more motor neuron unit, it was found that the waveform is better formed.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.9-15
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• 2000

• Proceedings of the KSR Conference
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• 2006.05b
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• pp.121-128
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• 2006

• Proceedings of the KSR Conference
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• 2006.05b
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• pp.59-66
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• 2006

• Journal of IKEEE
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• v.20 no.2
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• pp.163-166
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• 2016

It is important to operate the driving circuit under the optimal condition through precisely sensing the power consumption causing the temperature made mainly by the MOSFET (metal-oxide semiconductor field-effect transistor) when a BLDC (Brushless Direct Current) motor operates. In this letter, a Super-junction (SJ) power TMOSFET (trench metal-oxide semiconductor field-effect transistor) with an ultra-low specific on-resistance of $0.96m{\Omega}{\cdot}cm^2$ under the same break down voltage of 100 V is designed by using of the SILVACO TCAD 2D device simulator, Atlas, while the specific on-resistance of the traditional power MOSFET has tens of $m{\Omega}{\cdot}cm^2$, which makes the higher power consumption. The SPICE simulation for measuring the power distribution of 25 cells for a chip is carried out, in which a unit cell is a SJ Power TMOSFET with resistor arrays. In addition, the power consumption for each unit cell of SJ Power TMOSFET, considering the number, pattern and position of bonding, is computed and the power distribution for an ANSYS model is obtained, and the SJ Power TMOSFET is designed to make the power of the chip distributed uniformly to guarantee it's reliability.

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.524-531
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• 2006

Environmental problem is one of important global issues. Transportations are main pollutant emission sources. Although railroad is stilt an environmental-friendly transportation, its environmental impact has been increased continuously. Especially, because a large amount of environmental impact is released from vehicles and facilities, it is necessary to assess and to reduce their environmental impact. Life cycle assessment (LCA) is a representative method which can evaluate environment impact through the whole life cycle of a product or a process. In this study, the environmental impact of seat in the electric motor unit (EMU) was analyzed quantitatively with its material using lift cycle assessment (LCA). As a result, the characteristics of environmental impact were investigated differently with the material of seat. Among ten impact categories, the seat with aluminum and FRP showed the highest ozone depletion (OD). On the other hand, in the seat with stainless steel and plastic, fresh water aquatic ecotoxicity (FAET) and marine water aquatic ecotoxicity (MAET) were high relatively. Therefore, the parts of EMU must be selected considering the characteristics of environmental impact in future.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.470-474
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• 2010

Up until now, power centralized trains have been produced due to the maintenance convenience and comfortableness, but there are some problems, such as limitation of viscosity and maintenance difficulty of railroad due to recently increasing axle mass. In order to improve the problems, power decentralized trains have been developed to improve traction power. In the case of using electrical braking system, it is possible to improve braking friction power. Induction motors have been developed for power decentralized high speed train because of less structural defection, and low maintenance and production cost. However, induction motors have limitations, such as assuring enough power capacity and efficiency with reduced size. PMSM (Permanent magnet synchronous motor) have been newly developed to improve shortcomings of induction motors. The PMSM can be produced small and light weighted. Also if the PMSM and induction motors have the same size and power capacity, the PMSM have better power efficiency. In this pater, the prototype and modified type of PMSM for "High-speed Electric Multiple Unit-400km/h eXperimmen" will be introduced.

• 전자공학회논문지 IE
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• v.43 no.3
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• pp.34-40
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• 2006

Usually, fluid or fuel supply device need space to need special sensor to control motor, attaches with ancillary equipment to attach sensor. Also, difficult point follows need signal line and other circuit etc. In this paper, used that proposed control system that use hall sensor to solve discomfort and problem and difference control principle of system happens in current flow according to motor action step. Also, could reduce breakdown by sensor establishment, reduce material costs and personnel expenses as well as control system superior. Auto-pumping system sees that will can apply, develop several kind of device that use system hereafter to all fluid supply systems through soft-ware adaptation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.1
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• pp.21-26
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• 2017

Failure of high-voltage transmission line, which is responsible for large-scale power transmission, can be reason for system voltage instability. There are many methods to prevent voltage instability like adjustment of equipment, the generator voltage setting, and load shedding. Among them, the load shedding, have a problem of economic loss and cascading effect to power system. Therefore, the execution of load shedding, amount and timing is very important. Conventionally, the load shedding setting is decided by the preformed simulation. Now, it is possible to monitor the power system in real time by the appearance of PMU(Phasor Measurement Unit). By this reason, some of research is performed about decentralized load shedding. The characteristics of the load can impact to amount and timing of decentralized load shedding. Especially, it is necessary to consider the influence of the induction motor loads. This paper review recent topic about under voltage load shedding and compare with decentralized load shedding scheme with conventional load shedding scheme. And simulations show the effectiveness of proposed method in resolving the delayed voltage recovery in the Korean Power System.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.3
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• pp.107-114
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• 2001

Electro-mechanical battery (EMB) consists of a high-speed fly wheel with an integral motor/ generator suspended on magnetic bearings and in an evacuated housing. Permanent magnet (PM) machines as the EMB motor/ generator are a popular choice, since there are no excitation losses which means substantial increase in the efficiency. In this paper we present the comparison of conventional slotted and slotless ring-wound types, aimed at EMB and other high-speed drives. We firstly discuss the topology of each machine for this particular application. these machines are primarily designed as 1kW two-pole PM generator with the rated speed of 40000 rpm. the motoring torque of 0.51 Nm has to be enough to accelerate the flywheel to the rated speed. We then present the comparison of the open-circuit field, the armature reaction field and winding inductance. next we analyze the induced voltage and the developed torque per unit stack length and unit weight of different machines. Finally, we estimate and compare the losses and the efficiency at motoring and generating modes.