• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.326-333
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• 2004

This paper presents the structural characteristics analysis of a high-speed horizontal machining center with spindle speed of 50, 000rpm and feedrate of 120m/min. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil-jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motor and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guide. The structural analysis model of the high-speed horizontal machining center is constructed by the finite element method, and the validity of structural design is estimated based on the structural deformation of the high-speed horizontal machining center and spindle nose caused by the gravity and inertia forces.

• The Korean Journal of Pain
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• v.26 no.3
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• pp.286-290
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• 2013

Air injected into the epidural space may spread along the nerves of the paravertebral space. Depending on the location of the air, neurologic complications such as multiradicular syndrome, lumbar root compression, and even paraplegia may occur. However, cases of motor weakness caused by air bubbles after caudal epidural injection are rare. A 44-year-old female patient received a caudal epidural injection after an air-acceptance test. Four hours later, she complained of motor weakness in the right lower extremity and numbness of the S1 dermatome. Magnetic resonance imaging showed no anomalies other than an air bubble measuring 13 mm in length and 0.337 ml in volume positioned near the right S1 root. Her symptoms completely regressed within 48 hours.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.453-456
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• 2005

In recent years, the demand of a silent indoor air-conditioner is the essential research filed when the product is developed. In this study, through the design modification of the noise and vibration source, the noise and vibration level of the package air-conditioner is reduced. The modal analysis of the motor bracket is performed by FEM. To find the most suitable shape of the motor bracket, Design of Experiments is applied.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.5
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• pp.620-625
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• 2013

This paper presents the design of a switched reluctance motor (SRM) for electric air conditioning compressors which are applied to hybrid electric vehicles (EVs). The motor for driving air conditioning compressor which is recently used on EV(electric vehicle) / HEV (hybrid electric vehicle) is PMSM(permanent magnet synchronous motor) or BLDCM(brushless DC motor). However disadvantage of motors that uses permanent magnets are vulnerable to high temperatures because of the demagnetization by the high temperature and the permanent magnet is expensive because of the high price of rare earth materials from China's monopoly. Therefore, in the automotive insustry is interested in the non-rare-earth motors. SRM has many advantages. it's resistant to high temperatures, price is cheaper, because there are no permanent magnets and winding in the rotor. Also it's high relability and efficiency, suitable for high-speed operation because of structure is simple. In this paper, the SRM, non-rare-earth motor, are designed, analyzed and experimented drive to replace an existing electric compressor drive motor.

• Journal of Drive and Control
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• v.9 no.4
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• pp.1-7
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• 2012

The voice coil linear force motor is a kind of a direct drive motion device that uses a permanent magnetic field and coil winding to produce force. In order to design a voice coil linear force motor, an exact calculations of the required force, the flux density in air gap and the flux pathway are needed. A conventional method can be used usually to calculate the flux density in air gap, but with this method it is needed to find a magnetic circuit revision constant. In this paper a voice coil linear force motor is designed by conventional design method and analyzed by 3D simulation program "Flux". For the prototype linear force motor, the results of the calculated by conventional design method and the analyzed by 3D simulation program are compared with the test result. Finally it is showed that the magnetic circuit revision constant which is found by comparing of the analyzed and the measured data can be used for the design of the voice coil type linear force motor to minimize the trial and error.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.63-70
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• 2011

This paper presents the design and operating characteristics of the novel cylindrical linear motor which is designed for the long stroke XY stage. In the long stroke structure, the air gap is changed by the distortion and bending effects, and it makes additional position error in the XY stage. In order to consider the distortion and bending effects of the long stroke, the field part of the cylindrical linear motor is designed as an open structure, and the stroke is supported by the bridge guide which is positioned in the open field part. The mechanical bridge guide can reduce the bending effects of the stroke and can keep a constant air gap. The detailed design process of the proposed cylindrical linear motor is presented in this paper. The proposed motor is analyzed by the 3D FEM technology. The practical XY stage which uses the proposed motor is tested to verify the propose novel cylindrical linear motor. The FEM and experimental results show the effectiveness of the proposed motor.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.4
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• pp.99-104
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• 2020

In this study, the temperature distribution and heat transfer characteristics of each component in a solenoid motor system were numerically investigated when heat is generated by the steel pad attached to the solenoid ring of the motor. It was found that the internal airflow was complicated by the inflow velocity of air and the rotation of guide rollers and solenoid rings. Based on the numerical results, the tendency for temperature changes in the steel panel was lower due to the contact of the cooling air in the front in the rotational direction, and the peak temperature was at the front of the center. In particular, it was confirmed that as the air inflow rate was increased, the temperature was reduced due to strong convection. The temperature of the iron plate pad was decreased as the convective heat transfer coefficient was linearly increased with increasing airflow around the solenoid ring. In addition, the temperature of the iron plate panel was rapidly increased with increasing heat generation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.306-310
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• 2010

On account of small size and light weight, a high-speed machine is regarded as a key technology for many future applications of drive systems. In high-speed applications, permanent magnet synchronous motors have a number of merits such as high efficiency and high power density. Therefore, they are suitable for driving the air-blower of a fuel cell electric vehicle (FCEV) where space and energy savings are critical. Particularly, a surface-mounted permanent magnet synchronous motor (SPMSM) of them is mainly used as a high-speed machine. However, the motor has a fatal flaw due to a retaining can to maintain the mechanical integrity of a rotor assembly. The can results in the increase of magnetic air-gap length in the SPMSM. Thus, in this paper, an interior permanent magnet synchronous motor (IPMSM) is applied in order to drive the air-blower of FCEV instead of the SPMSM, and the experimental results of two models are compared to verify the capability of the IPMSM for high-speed applications.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.468-471
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• 2005

The Air Quality Sensor(AQS), located near the fresh air inlet, serves to reduce the amount of pollution entering the vehicle cabin through the HVAC(heating, ventilating, and air conditioning) system by sending a signal to close the fresh air inlet door/ventilation flap when the vehicle enters a high pollution area. One chip sensor module which include above two sensing elements, humidity sensor and bad odor sensor was developed for AQS (air quality sensor) in automobile. With this sensor module, PIC microcontroller was designed with back propagation neural network to reduce detecting error when the motor vehicles pass through the dense fog area. The signal from neural network was modified to control the inlet of automobile and display the result or alarm the situation. One chip microcontroller, Atmega128L (ATmega Ltd., USA) was used. For the control and display. And our developed system can intelligently detect the bad odor when the motor vehicles pass through the polluted air zone such as cattle farm.

• Journal of Power System Engineering
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• v.17 no.3
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• pp.111-122
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• 2013

After the port opening in 1876, the western people made joseon image as the land of morning calm. there was a conception that joseon was a uncultivated country in the meaning of the land of morning calm. famous modernists such as gil-jun yu, kwang-su lee also had same conception. but such conception began to change in 1930's. the number of motor vehicle began to increase rapidly in 1930's. and also many of motor vehicle were equipped with air horn or electronic horn instead of bulb horn. bulb horn made thick and low rubber sound. but air horn or electronic horn made sharp and high metallic sound. city people of colonial joseon began to recognize air horn or electronic horn as city noise. so they tried to control the use of air horn or electronic horn. finally, in late 1930's, the use of air horn and electronic horn were prohibited.