• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1079-1080
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• 2011

This paper deals with the operating characteristics of induction motors with broken rotor bar, stator winding inter-turn short and their complex fault conditions. The considered operating characteristics are phase current, torque and speed. Since the operating characteristics of induction motors are directly related to their slip conditions, this paper built the experimental set to adjust the speed of induction motor with a permanent magnet synchronous generator connected to a load bank. From the various experimental results, it is shown that the faults do not highly affect on the operating characteristics of induction motors in low slip conditions, but the fault characteristics can be easily found in larger slip conditions.

• Journal of Magnetics
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• 제17권4호
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• pp.285-290
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• 2012

Electric Power Steering (EPS) system is superior to conventional Hydraulic Power Steering (HPS) system in aspect of fuel economy and environmental concerns. The EPS system consists of torque sensor, electric motor, ECU (Electric Control Unit), gears and etc. Among the elements, the torque sensor is one of the core technologies of which output signal is used for main input of EPS controller. Usually, the torque sensor has used torsion bar to transform torsion angle into torque and needs linear characteristic in terms of flux variation with respect to rotation angle of permanent magnet. The torsion angle of both ends of a torsion bar is measured by a contact variable resistor. In this paper, the sensor is accurately analyzed using 3D finite element method and its characteristics with respect to four different shapes of the stator teeth are compared. The four shapes are rectangular, triangular, trapezoidal and circular type.

• EDISON SW 활용 경진대회 논문집
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• 제4회(2015년)
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• pp.460-466
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• 2015

The remaining features in this study using the Freecad proceeds according to the overall effect was not supported by the modeling Freecad were conducted a study to complement using the CATIA program or other commercially available. The focus of this study is that there can be obtained the stability through the center of gravity of the balancing of two parts by increasing the weight of the other magnet through a Fortuna other end of the weight of the bar, using the center of gravity. Finally, to find the optimal design of the weight and thickness of the main bar through the center of gravity balancing is the purpose of this study.

• 한국자동차공학회논문집
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• 제8권1호
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• pp.163-171
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• 2000

The aim this study is to provide fundamental informations for the development of magneticfluid damper. To achieve the aim. the damping effect of magneticfluid is investigated by experiments that the diameter of inner circular bar and the input amplitude vary in the magnetic field generated by the permanent magnet and the electromagnet. From the study, the following conclusive remarks can be made. As the diameter of inner circular bar and the input amplitude increase. the damping effect is improved. And we can know that as the contact area between inner circular bar and magneticfluid increases, damping ratio is improved. Also we consider the cases that there is magnetism generated by electromagnet and DC voltage is supplied to electromagnet from 10V to 50V by 10V. In these cases, the amplitude ratio decreases sharply from 1.8 1.0 And for these cases, the damping ratio is .745.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.971-975
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• 2005

In this study, a car-door-controlled collision protection system using proximity sensor is proposed and its preliminary analysis and several preliminary experiments are conducted. The proposed system has three additional sub-components on the car-door that is, a pair of extra electro-magnetic actuator that are attached to the sliding bar of the open/close car-door four-bar mechanism, a proximity sensor that would be attached to the outside surface of the door which is likely to frequently contact to the object and a driving control circuit of the whole system. A proximity sensor is used to detect object close to the car-door, the driving control circuit provides actuating power command to the electro-magnets to generate braking force to stop the swing motion of the car-door. It is verified through kinematic analysis of the four-bar car-door open/close mechanism and through experiments that the magnitude of maximum electronic magnetic force could provide the braking force enough for this application. For this purpose, an electro-magnet driving circuit is implemented and tested. And also to increase the safety of the system a time delay circuit is implemented and tested.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1076-1078
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• 2004

This paper deals with eddy-current magnetic repulsion system. The passive system employing permanent magnets on the moving part maximizes levitation forces by using Halbach array and conducting plate. We predict force characteristics according to permanent magnet array and conducting bar

• 구강회복응용과학지
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• 제24권1호
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• pp.91-104
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• 2008

최근에, 의치의 유지, 안정성, 지지를 개선시키기 위해 골유착 임플란트가 사용되고 있다. 여러 연구에서 하악에 두 개의 임플란트를 식립한 후 제작된 피개의치가 환자 보철에서 기능과 만족의 유의한 증가를 나타내고 있다. stud, magnet, 그리고 bar attachment를 포함하여 다양한 attachment 시스템을 사용해 임상적으로 예상 가능하고 효과적인 것이 증명되었다. 본 증례에서 2개의 임플란트를 이용한 피개의치가 무치하악의 치료를 위한 고려의 기본이 될 수 있다는 것을 나타낸다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1718-1720
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• 2004

This paper is focused on the improvement of reflection angle of an optical scanner by changing a shape of a torsion bar attached with an optical scanner reflector(mirror). In order to improve the light efficiency of the optical scanner by virtue of the magnetic effect, which tiny magnets are attached under both ends of the optical scanner reflector. and hence the optical scanner reflector was operated in relatively lower driving voltage. By changing the torsion bar's shape I type into S type, we've got the lower resonant frequency(32.5Hz) of an optical scanner than that of conventional one(50Hz). According to these results. The reflection angle of an optical scanner with magnets was much larger in the range of about 14.8$^{circ}$ without a magnet. By making use of a magnetic actuator instead of a conventional electrostatic actuator, the optical scanner was less influenced from outdoor dust or moisture.

• 대한치과보철학회지
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• 제57권3호
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• pp.271-279
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• 2019

심한 하악 치조골 흡수룰 보이는 완전 무치악 환자에서 의치는 환자의 저작 효율이 극히 저하되며 특히 치조골의 형태가 불규칙한 경우 의치의 안정성은 더 떨어질 수 있다. 이때 임플란트를 통한 지지를 얻는 피개의치를 통해 편안감 회복과 향후 지속적인 치조골 흡수를 줄이는데 도움을 줄 수 있다. 임플란트 피개의치를 위한 하방의 attachment는 크게 bar attachment와 solitary attachment로 나뉘며 임플란트 고정체의 위치가 하악 전방 치조골에 있으면서 의치 전체가 견고한 지지를 얻기 위해서는 bar attachment가 유리하고 구치부에도 고정체가 위치하며 쉬운 착탈과 유지관리의 편의를 얻고자 하면 solitary attachment를 고려할 수 있다. 본 증례는 환자의 상황에 따른 임플란트 식립 위치 결정, attachment를 선택을 통하여 임플란트 피개의치를 다양하게 적용하여 만족할만한 결과를 얻어 이를 보고하는 바이다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.382-385
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• 2003

In this paper, the solenoid for high-voltage circuit breaker which is composed of bobbin, solenoid coil, stationary core and plunger was studied. The solenoid is made of a soft magnetic iron bar with a large number of coil windings. when an electric current passes through this, this stationary core becomes the strong magnet used for hydraulic and pneumatic valve of a solenoid operated valve. For the performance evaluation of the solenoid for high-voltage circuit breaker, electromagnetic characteristics and dynamic characteristics were analyzed. And, the parameters which is related to performance improvement were investigated.