• 한국자동차공학회논문집
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• 제20권3호
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• pp.52-57
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• 2012

Proper door effort is required for the safety of passenger and pedestrian while securing door operating convenience. 3D finite element analyses for a hybrid door checker were carried out to estimate door checker arm resistance force. And, from the estimated door checker arm resistance force and theoretically calculated self-closing force, door effort was predicted. The analysis results at checker arm peaks showed excellent correlation with the test results. Also, in order to reduce solving time, a modified model with simple spring element was investigated. Finally an equation to easily calculate checker arm resistance force from checker arm shape and spring constant was suggested and its usefulness in early design stage was discussed.

• 한국자동차공학회논문집
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• 제2권3호
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• pp.94-104
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• 1994

In order to improve engine performance and its reliability it is very important to find the friction force between piston-ring assembly and cylinder wall in engine operating conditions. A new system was developed for the piston-ring assembly friction force measurement. This system had a relatively high fundamental frequency at 884 Hz and a fine resolution of 0.5N in friction force measurement. Comparing with existing floating liner systems this systems required small installation space and at the same time alleviated the system noise problem induced by the thrust and slap impulse forces.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1517-1520
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• 2003

In this paper, we design a wedge type rail-clamp which can protect container crane from wind with constant clamping force regardless of the operating period. When we design wedge type rail clamp, it is important to determine the weight for locker to descent smoothly with an initial clamping force of rail and pad. Therefor, this paper suggest a process to decide a wright within proper range which could be obtained using FEA of wedge type rail clamp.

• 전기학회논문지
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• 제60권4호
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• pp.746-752
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• 2011

In this paper, a novel bearingless switched reluctance motor (BLSRM) with double stator is proposed. This motor has two stators. Torque stator is outside, which mainly produces rotational torque. Radial force stator is inside, which mainly generates radial force to suspend the rotor. A novel structure and operating principle are presented. And characteristics of the proposed structure such as magnetic flux distribution, inductance, torque and radial force are analyzed through finite element method. From the analysis, the proposed BLSRM has linear characteristic of radial force and independence from torque current.

• Journal of Mechanical Science and Technology
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• 제16권12호
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• pp.1643-1651
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• 2002

Magnetic levitation systems are required to have a large operating range in many applications. As one method to solve this problem, Time Delay Control (TDC) is applied to a single-axis magnetic levitation system in this paper A reduced-order observer is utilized to estimate states excluding measurable states in the control law. The system consists of a square air-core solenoid and a circular permanent magnet attached on a plastic ball. Theoretical magnetic forces of the system are obtained on the basis of the location of the magnet around the solenoid. The magnetic levitation force is obtained by the experiment, and then compared with the theoretical one. As the results of the control experiments, the nonlinear controller (TDC : 1-2 ㎜) has a larger operating range than the linear controller (PD control : 1-1.4 ㎜), and is superior to linear. control in the robustness to the modeling uncertainty and the performance of the disturbance rejection.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.1159-1162
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• 1995

In the continuous process systems, traction between a moving web and rollers is one of key mechanisms for the study of major issues including the distributed control of tension, guiding, wrinkling, and scratching. Energy is transferred from the driven rollers to the web and from the web to the idle rollers through traction. The characteristics of friction plays a major role in the determination of the traction force between the moving web and the rollers. In this paper, a procedure to determine the frcition coefficient between the moving web and rollers is devoloped. An experimental setup to validate the procedure is devised. Experimental results showed that the value of traction coefficient decreases as the operating web speed increases and increases as the operating web tension and wrap alngle increase.

• Tribology and Lubricants
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• 제12권2호
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• pp.65-73
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• 1996

Rapid increase of Refrigeration and Air conditioning system in modem industries brings attention to the urgency of core technology development in the area. This paper presents theoretical investigation of the lubrication characteristics of rotary compressor for refrigeration and air conditioning. In order to analyze the lubrication characteristics of the main & sub bearing of rotary compressor, the bearing force and locus of shaft center are analyzed by the dynamic analysis of rotary compressor and numerical analysis of Reynolds equation as the operating condition is changed in various ways. In this paper, we used the Runge-Kutta method for the dynamic analysis of rotary compressor and the SOR (Successive OverRelaxation) method for the numerical analysis of Reynolds equation. The result shows that the operating condition of sub bearing is severer than that of main bearing, and eccentricity ratio grows as the bearing force increases. It is believed that the result can be applied to the design of alternative refrigerant rotary compressor.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1535-1540
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• 2008

본 논문은 실험실에서 개발된 테스트 장치를 사용하여 여러 고무의 마찰 마모 특성을 실험적 연구에 의해 분석하였다. 마찰 계수는 하중과 온도 등과 같은 여러 가지 속도 조건 하에서의 마찰력과 측정된 수직하중으로부터 계산되었다. 자동차에 사용되는 타이어는 여러 가지 작동 상태에 따라 마찰 특성의 관계가 확인되었다.

• 한국산학기술학회논문지
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• 제10권3호
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• pp.488-492
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• 2009

본 논문은 자동차의 엔진오일에 사용되는 여러 윤활기유에 대하여 비마모 특성을 실험적 연구에 의해 분석하였다. 비마모량 점도와 온도 등과 같은 여러 가지 속도 조건 하에서의 마찰력과 측정된 수직하증으로부터 계산되었다. 엔진오일에 사용되는 기유는 여러 가지 작동 상태에 따라 마찰 특성의 관계가 확인되었다.

• 한국멀티미디어학회논문지
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• 제16권6호
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• pp.689-699
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• 2013

로봇 원격조종 방법은 1:1, 1:N, N:1, 그리고 N:N의 다양한 방법이 있다. 오퍼레이터가 원격지 로봇을 제어하기 위해서는 로봇의 주변 상황, 모바일 장치의 충돌 가능성, 그리고 매니퓰레이터의 힘을 인지할 수 있어야 한다. 원격조종에서는 데이터 통신과 처리에 소요되는 시간에 따른 지연이 발생하는데, 이 시간 지연은 로봇의 충돌과 햅틱 기반 제어에 있어 양방향 힘 반영에 따른 매니퓰레이터의 바이브레이션과 과도한 힘 반영을 초래할 수 있다. N:N 제어 방식은 근래 개발 중인 조종 기술로 멀티 오퍼레이터가 멀티 로봇을 스위칭하면서 제어하는 구조를 가진다. 이 구조를 구현하기 위해서는 오퍼레이터가 어떤 로봇을 제어할 것인지, 또는 그 로봇의 어떤 장치를 제어할 것인지에 대한 스위칭 기능이 필요하며, 다수의 오퍼레이터가 함께 원격조종을 수행할 때에는 이 스위칭 알고리즘이 반드시 필요하다. 또한 오퍼레이터의 성향에 따라 조종 성향이 달라지므로 이를 일반화하기위한 방안도 요구된다. 본 논문에서는 다수의 로봇과 다수의 오퍼레이터가 원격으로 로봇들을 제어하여 작업을 수행할 수 있는 햅틱 기반 제어 환경을 구축하는 방안과 구현에 대하여 기술한다.