• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.90-92
• /
• 2008

A novel solving technique has been developed to analyze the dynamic characteristics of high speed Thomson-coil arc eliminator. The electromagnetic repulsion actuator based on Thomson-coil is taken as the driving part of the arc eliminator, due to which, the opening and closing time is quite short compare to other type actuators. The electromagnetic repulsion actuator is composed of one repulsion plate and two fixed coils, corresponding to the opening coil and closing coil, respectively. The new solving technique is derived based on the equivalent electric circuit model of the system which is set up by dividing the repulsion plate into multi segments using adaptive segmentation method. This solving technique is applied to the dynamic characteristic analysis of electromagnetic repulsion actuators in high speed Thomson-coil arc eliminators. The calculation results are testified by the FEM calculation results and experiment results.

• 대한치과보철학회지
• /
• 제25권1호
• /
• pp.119-135
• /
• 1987

For the determination of instantaneous centre of rotation in the mandibular movement, the habitual opening path was recorded on the sagittal tracing plate by a Gnathorecorder attached on the lower anterior teeth which was designed for this study. The opening path was demonstrated mathematically and the instantaneous centre of rotation in the opening path were calculated and plotted by computer programs, and then a computer graphic movement of the mandible was obtained according to the opening path. The hinge path of posterior border movement was graphied by the Gnathorecorder as well and demonstated mathematically. This hinge path was compared with the same obtained by Visitrainer to prove a reliability of the Gnathorecorder. The results obtained from this study were as follows. 1. The habitual opening path and hinge path obtained from the Gnathorecorder movement were expressed mathematically as follows: $y=0.11x^2-0.66x+3.09$ (equation of opening path), $y=0.04x^2+0.21x+3.71$ (equation of hinge path), and a kinematic hinge axis was not shown in the equation of kings path. 2. The early habitual opening movement of the mandible demonstrated almost a straight opening path or an arc motion with the larger radius and it's centre of rotation moved parallelly in the more rear and lower position than a kinematic hinge axis. 3. Instantaneous centre of rotation occured along with the translation of the condyle, and mandible was rotated around an axis in the close to the maximum opening and then moved toward the forward and upward position. 4. There were some similarities between the articular eminence and the movement pattern of a special point which was the kinematic hinge axis.

• 한국생산제조학회지
• /
• 제25권1호
• /
• pp.89-95
• /
• 2016

This study investigated the design factors of the opening area in order to consider the kinematic stability of a valve plate, conducting an analysis of the reduction effects of pressure pulsation and flow ripple depending on the design factors, using the $SimulationX^{(R)}$ (Germany) hydraulic analysis program. Further, we performed a structure analysis to confirm the kinematic stability of the valve plate in a swash plate type piston pump, and analyzed the effects of pulsation on a 1-step V-type notch, 2-step V-type notch, and 2-step U-type notch to determine the effects of pulsation reduction. Finally, we show the effectiveness of our proposed design of the pre-compression sections on a valve plate in terms of low pulsation by using the hydraulic analysis program, $SimulationX^{(R)}$.

• 한국자동차공학회논문집
• /
• 제13권2호
• /
• pp.10-15
• /
• 2005

This study was initiated to evaluate the cooling performance of CAC (charged air cooler) and radiator in the engine room of a mini bus. So we had firstly to predict the mass flow rate coming from radiator grille and front bum per opening using computational fluid dynamics (CFD) simulation based on 3D configuration. And simulations were carried out for different cooling module layout and bum per opening hole size on sam e vehicle operating condition. Simulation results show that CAC cooling performance at reverse protecting plate-applying model was much efficient than that of the bum per opening hole size-increasing model in IMTD point of view. Part of the CFD simulation results was com pared to with experimental data. It was confirm ed that the CFD approach using STAR-CD based on pursuing no-com promise solution could provide design engineers with useful design information in the early design stage of vehicle development.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
• /
• pp.429-437
• /
• 1999

Width variation of the top and bottom ends of steel at finishing rolling in a plate, has been investigated. It was found that width variation after finishing rolling is affected by edging, broadside rolling ratio, longitudinal rolling ratio, width shape after broadside rolling, temperature, width-to-thickness ratio, and so on. A neural network modelling of back propagation has been conducted on the width variation during rolling. Based on these prediction models, a width control system, by which the roll opening and closing of the hydraulic AWC edger can be adjusted during edge rolling in finishing rolling passes, has been developed. Compared to conventional width model, the neural network model is much accurate in a model. The width control system is applied to a newly built production mill.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2007년도 정기 학술대회 논문집
• /
• pp.127-132
• /
• 2007

This paper has the object of investigating dynamic stability of opening thick plates on Pasternak foundation by means of finite element method and providing Kinematic design data for mat of building structures. Finite element analysis of Tapered Thick plate is done by use of rectangular finite element with 8-nodes. In order to analysis plate which is supported on Pasternak foundation. the Winkler foundation parameter is varied with $10^2$, $10^3$ and the shear foundation parameter is 5, 10. The ratio of force to critical load is applied as 0.4, 0.6, respectively. This paper analyzed varying Tapered Ratio and Concentrated Mass.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 추계학술대회논문집
• /
• pp.894-897
• /
• 2004

This paper has the object of investigating dynamic stability of opening thick plates on Pasternak foundation by means of finite element method and providing Kinematic design data for mat of building structures. Finite element analysis of Tapered Thick plate is done by use of rectangular (mite element with 8-nodes. In order to analysis plate which is supported on Pasternak foundation, the Winkler foundation parameter is varied with $10^2,\;10^3$ and the shear foundation parameter is 5, 10. The ratio of In-plane force to critical load is applied as 0.4, 0.6, respectively. This paper analyzed varying Tapered Ratio.

• 대한의용생체공학회:의공학회지
• /
• 제25권6호
• /
• pp.551-556
• /
• 2004

본 연구에서는 진단 방법의 정확성이 아직까지 구체적으로 규명되지 않고 있는 어린이의 성장 발육을 체계적이고 과학적으로 측정할 수 있는 방법을 제시하고자 시도하였다. 현재 많이 이용되고 있는 성장 진단 방법은 X-ray 영상을 이용한 각 관절 부위의 성장판의 개폐 분석이다. 그러나 X-ray 방식은 성장 진단에서 요구되는 주기적이고 반복적인 측정을 하지 못함과 동시에 방사선 노출이라는 단점을 가지고 있다. 따라서 인체에 무해한 초음파 영상을 이용한 성장판 개폐 분석 대체 가능성을 평가하기 위해 종골의 초음파 광역 감쇄 영상을 이용한 프로파일 분석 및 성장판 영상 분석 알고리즘을 제시하였다. 본 연구에서는 7세～16세의 어린이 269명에 대해서 X-ray를 이용하여 무릎, 손가락, 종골에서의 성장판 영상을 얻었다. 또한 초음파 방식을 이용하여 종골의 성장판 영상을 얻었다. 각 관절에서의 성장판 개폐 유무 시기는 각 개인별로 측정 방법에 따라 조금의 차이는 있으나 전반적으로 일치하였다. 또한. X-ray방식과 초음파 방식에 의한 성장판 영상을 비교한 결과 상호 높은 연관성을 나타내었다. 이와 같이 성장판을 정확하게 측정하기 위해 도입된 초음파 프로파일 분석 알고리즘은 기존의 X-ray 영상 방식에 의한 성장판의 측정을 대체할 수 있을 것으로 사료된다.

• 대한치과보철학회지
• /
• 제27권1호
• /
• pp.55-81
• /
• 1989

Recently the instantaneous center concept has been to understand the biomechanics by which a tissue derangement causes a mechanical derangement in human joint. Therefore, to understand the biomechanics of temporomandibular joint (T.M.J.) as a part of human joint, it is necessary to clarify the instantaneous center of rotation (I.C.R.) in the mandibular movement. Twenty male subjects without T.M.J. disorder and mandibular deviation during the mandibular movement were selected for this study. The habitual opening and closing paths were recorded on the paper of the sagittal metal plate by two pencil markers connected to the resin open clutch attached on the lower teeth, which was designed for this study. The coordinates of the 33-target points and the 109-anatomical landmarks were obtained using a Summagraphic digitizer connected to a 18AT computer. The original raw data of the opening and closing paths were smoothed by B-spline curve fitting technique and then the I.C.R. pathways were determined mathematically by the computer using algorithm for finding the I.C.R. of a planer rigid body model. Also the opening and closing movements of the mandible were simulated according to the determined I.C.R. The results obtained from this study were as follows. 1. At the early opening and the last closing, I.C.R's were almost distributed around the mastoid process outside the mandibular body without the presence in the region of the mandibular condyle. 2. The I.C.R. pathway showed variable patterns to each subject at the opening and closing movements. 3. The K constant with uniform pattern was obtained by the rotation angle times the radius, which was assumed to the index of the mandibular movement. 4. The opening and closing movements of the mandible were simulated by the I.C.R. pathways at the habitual opening and closing movements. 5. The mandibular condyle was rotated or translated accordng to the relative rotation angle and radius of the determinant factors of K contant.

• 한국해양공학회지
• /
• 제7권1호
• /
• pp.124-132
• /
• 1993

In order to examine the effect of anisotropy and stress ratio on fatigue crack propagation rate and opening-closing behavior and also arrest behavior by single tension peak overload, the fatigue tests of constant amplitude atress and single tension peak overload adding to cycle of constant amplitude were carried out in stress ratio of -0.4, -0.2, and 0.4 with materials of T-L and L-T directions in 2024-T3 aluminum alloy plate. Crack opening-closing begavior were measured by the compliance method using COD gage and strain gage. In case of the crack opening-closing behavior was measured by strain gage, the effect of stress ratio is unchangeable. But in the case of COD gage, that is remarkably decreased. Fictitious effective stress intensity factor(U sub(f)) and effective stress intensity factor ratio(U) in L-T direction was higher than those in T-L direction and also threshold arrest overload ratio incrased as stress ratio decreased and that of T-L direction was higher than that in L-T direction.