• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.317-322
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• 2002

There are many researches to identify the rigid body properties from the mass-line obtained by impact hammer testing. The correct rigid body properties of the structure may be estimated if the mass-line of the structure could be obtained exactly. When the structure is mounted by elastic materials, the mass-line cannot be read correctly from the impulse response spectrum. The reason is due to the effects of rigid body modes of mounted structure. In this paper, the effects of rigid body modes of mounted structure to the mass-line are discussed and the method to remove these effects is also presented.

• 한국통신학회논문지
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• 제26권10B호
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• pp.1419-1427
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• 2001

본 논문은 연속영상에서 non-rigid object를 자동으로 분할하고 알고리즘을 제안하였다. Non-rigid object는 형태의 변화가 일정하기 않은 object로서 기존의 분할 알고리즘과는 다른 새로운 분할 알고리즘을 필요로 한다. 본 논문에서는 특히 구름이나 연기와 같이 형태의 변화가 큰 non-rigid object를 자동으로 분할하는 알고리즘을 제안하였다. 제안된 알고리즘은 공간분할, 시간분할, 그리고 공간분할과 시간분할의 결합의 세 가지 단계로 구성되어 있다. 공간분할은 영상에서 픽셀의 intensity를 마코프 랜덤 필드로 가정하고 에너지 최소화를 통해 영상을 분할한다. 시간분할은 속도벡터를 기반으로 하여 움직임이 있는 영역만을 분할한다. 마지막으로 공간분할과 시간분할을 결합하여 non-rigid object의 최종적인 분할을 수행한다. 실험결과, 제안된 알고리즘은 연속영상에서 non-rigid object를 자동으로 분할함을 확인할 수 있었다.

• 한국공간구조학회논문집
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• 제6권3호
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• pp.87-92
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• 2006

This paper is a study on the experiment and elasto-plastic discrete limit analysis of reinforced concrete circular cylindrical shell by the rigid-bodies spring model. In the rigid bodies-spring model, each collapsed part or piece of structures at the limiting state of loading is assumed to behave like rigid bodies. The present author propose new discrete elements for elasto-plastic analysis of cylindrical shell structures, that is, a rectangular-shaped cylindrical element and a rhombus-shaped cylindrical element for the improvement and expansion of this rigid-bodies spring model. In this study, it is proposed how this rigid element-bodies spring model can be applied to the elasto-plastic discrete limit analysis of cylindrical shell structures. Some numerical results of elasto-plastic discrete limit analysis and experimental results such as the curve of load-displacement and the yielding and fracturing pattern of circular cylindrical shell under horizontal load are shown.

• 한국공간구조학회논문집
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• 제1권2호
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• pp.111-116
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• 2001

This paper is a study on the elasto-plastic analysis of reinforced concrete precast large panel connections by rigid element spring model. In the analysis of rigid element spring model, each collapsed part or piece of structures at limiting state of loading is assumed to behave like rigid bodies. The present author propose new elements for the improement and expansion of the rigid element spring model. In this study, it is proposed how the rigid element method can be applied to the elesto-plastic analysis of precat large panel connections. Some numerical results of analytical modeling and load displacement curves are shown.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.351-356
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• 2011

Some materials show the character of rigid body in low frequency spectrum. The rigid body motions are consisted of translational and rotational motions. Especially, we can get the acceleration or displacement of a random point in the rigid body by analyzing rigid body transfer matrix at the car's engine and power train. Actually it is difficult to measure the acceleration by attaching the sensor inside of the engine and power train. So the hard to predict acceleration data can be achieved attaching the sensor on the outside of the engine and power train by analyzing the data of rigid body motion which the engine is operated using dynamo. Also this paper will show the change of predicted data and accuracy variation by not using all the measured data but a few exceptions of the point number.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1320-1327
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• 2017

In this paper, a contact loss simulator for a rigid catenary system was designed and used to analyze the effect on the power source according to the conditions of the rigid catenary system and pantograph. R-bar applied to a high-speed train among the real rigid catenary system was used in the contact loss simulator for rigid catenary systems. The excitation frequency generated with the movement of the railway vehicle was simulated. The characteristics according to the frequency and amplitude of the excitation frequency and the presence or absence of pantograph movement were analyzed. This work is considered to be helpful in analyzing the characteristics of contact loss in the interface between a real rigid catenary system and a rail vehicle.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2001년도 가을 학술발표논문집 Vol.28 No.2 (2)
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• pp.523-525
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• 2001

본 논문은 많은 수의 rigid body 물체들을 물리학에 기반하여 실시간으로 애니메이션하는 방법을 제안한다 rigid body 물체들의 움직임을 생성해내는 과정은 상당한 시간이 소요되며 또한 물체의 수가 증가함에 따라 계산시간이 급증한다. 본 논문에서는 Timewarp rigid body 시뮬레이션 알고리즘을 실시간 애니메이션에 적용하기 위해 시간당 생성되는 프레임 수에 따른 다단계 롤백 범위 적용을 하는 방법을 제안하고 실험을 통하여 시뮬레이tus 시스템의 효율성을 보인다.

• 한국정밀공학회지
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• 제27권4호
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• pp.46-52
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• 2010

A flexible-rigid multibody analysis was pen armed to examine the dynamic response of a heavy handling robot system under a worst motion scenario. A rigid body dynamics analysis was solved and compared with flexible-rigid multibody analysis. The modal analysis and test were also carried out to establish the accuracy and the validation of the finite element model used in this paper. For the flexible-rigid multibody simulation, stresses in several major bodies were interested, so that those parts are flexible and other parts are modeled as rigid body in order to reduce computer resources.

• Structural Engineering and Mechanics
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• 제34권4호
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• pp.399-416
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• 2010

The purpose of this paper is to utilize the numerical assembly method (NAM) to determine the exact natural frequencies and mode shapes of a multi-step beam carrying multiple rigid bars, with each of the rigid bars possessing its own mass and rotary inertia, fixed to the beam at one point and supported by a translational spring and/or a rotational spring at another point. Where the fixed point of each rigid bar with the beam does not coincide with the center of gravity the rigid bar or the supporting point of the springs. The effects of the distance between the "fixed point" of each rigid bar and its center of gravity (i.e., eccentricity), and the distance between the "fixed point" and each linear spring (i.e., offset) are studied. For a beam carrying multiple various concentrated elements, the magnitude of each lumped mass and stiffness of each linear spring are the well-known key parameters affecting the free vibration characteristics of the (loaded) beam in the existing literature, however, the numerical results of this paper reveal that the eccentricity of each rigid bar and the offset of each linear spring are also the predominant parameters.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.184-187
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• 2000

This paper describes action of synchronous error between z axis and spindle axis on rigid tapping. Because rigid tapping cuts the threads synchronizing the movement of z axis to spindle rotation, synchronous error between z axis and spindle is very important. Increase of synchronous error degrades the accuracy of thread and crushes the tap in worst case. So we developed the realtime measurement system of synchronous error in order to know the action of synchronous error on rigid tapping. In result, we have known that synchronous error was increased according to rise of spindle speed and z axis speed. And because the cutting torque(M3-30Ncm∼M10-300Ncm) on rigid tapping are less than maximum motor torque(3500Ncm), it specially doesn't affect the synchronous error. The most important parameter which has affected the increase of synchronous error was acceleration/deceleration time. On worst case, spindle motor was tripped because of the excess of synchronous error. Because the acceleration/deceleration time ocuupies the most of the total cutting time, in order to move on the high speed rigid tapping, the acceleration/deceleration time of spindle must be remarkably reduced.