• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.2
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• pp.285-293
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• 2003

This paper explores an optimal design methodology for an auto lever using a genetic algorithm. Components of the auto lever have been designed sequentially in the industry, but this study presents a novel design method to determine the design parameters of components simultaneously. The genetic algorithm approach is described to decide a set of design parameters for auto lever. The authors have attempted to model the design problem with the objective of minimizing the angle variation of detent spring subject to constraints such as modulus of elasticity of steel, geometry of shift pipe, and stiffness of spring. This method gives the promising design alternative.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.151-157
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• 2017

암으로 인해 사망하는 인류를 위해 많은 연구자들이 노력하고 있다. 하지만 아직까지도 암세포를 선택적으로 파괴하여 완치하는 것은 힘든 일이다. 우리는 암세포에만 특이적으로 작용하는 항암제를 연구하고자 계획하였고, 암세포에만 선택적으로 약물 분자를 전달하는 캡슐을 만들기 위해서 컴퓨터를 이용한 계산화학 기법을 사용하기로 하였다. 3차원 캡슐은 고려할 변수가 너무 많기 때문에 2차원 캡슐을 모델링하여 어떤 조건에서 캡슐이 열리고 닫히는지 확인하였다. 고리의 길이와 고리 말단끼리 서로 끌어당기는 힘이 캡슐이 열리고 닫히는지 주요한 요인으로 작용하였고 이 결과를 통해 실제 항암제로의 적용가능성을 시뮬레이션을 통해 확인할 수 있었다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.7
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• pp.637-643
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• 2010

The paper is about the development of 6-DOF active vibration isolation systems using VCM. Firstly, formulate the vertical 3-DOF mathematical model under eccentric load, and compare the model with the case in which the center of mass is located at the centroid. And then, complete the 6-DOF mathematical model by formulating the horizontal 3-DOF mathematical model. Find main parameters by comparing the result of the frequency response test with simulation result on the model. Finally, achieve the performance of vibration isolation by applying loop shaping approach & feedforward controller.

• Journal of KIISE:Software and Applications
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• v.26 no.11
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• pp.1324-1331
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• 1999

물체의 공간에서의 운동을 다루는 공간 추론의 연구에서 충돌을 이해하는 것은 중요하다. 본 논문에서는 정성적 충돌 이론과 추론 기법을 소개하고자 한다. 충돌 해석에 있어 관련된 물체의 공간적 속성과 운동방향의 상호작용을 분석하여 충돌로 인한 힘과 운동 방향의 전달을 계산하였다. 추론 과정에 있어서는 충돌이 갖는 특성인 불연속적인 변화에 대한 분석과 회전 운동으로 인한 변화의 분석이 소개되었다. 제안된 충돌 이론과 추론 기법은 구현되어 자동차 충돌 사고의 충돌에 적용되어 유효성을 입증할 수 있었다. Abstract Understanding collision is important in spatial reasoning problems that study the motions of objects. This paper introduces qualitative collision theory and reasoning techniques. Force and motion transfers are computed by analyzing the interactions of the spatial properties and motions of the objects. This paper also presents inference techniques for handling discontinuous changes and angular changes by rotation. These theories and inference techniques are implemented and applied to real car-to-car collision accidents. The test results verify the reliabilities of our techniques.

• Proceedings of the KAIS Fall Conference
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• 2001.11a
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• pp.111-116
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• 2001

본 논문에서는 유체기계에서 사용되고 있는 홀로제트밸브의 감속기에 대하여 APM S/W로 시뮬레이션(simulation) 하였다. 수압과 외부의 힘에 의해서 전달되는 베벨기어의 설계검증 및 재설계 관하여 시뮬레이션을 하였다. 도면의 재원을 변경시키지 않고 기어의 수명을 시뮬레이션한 결과 SM45C를 Martempering하여 사용할 시 기어의 수명이 짧아 적절치 못하였고 고주파열처리강, 질화열처리강을 사용할 경우 기어의 수명시간이 12,957-20,983시간 이였고 침탄강을 사용할 시 기어의 수명은 영구적이었고 소재의 경도가 우수할수록 더 많은 허용굽힘응력과 허용접촉응력을 받을 수 있다는 것을 시뮬레이션을 통하여 입증된다. 그리고 기어의 검증결과로 기어를 다시 설계할 경우 고주파나 질화강으로 하여 기어의 잇수가 1-3개만 늘어나고, 피치원의 지름이 4-12mm늘어나면 영구적으로 사용할 수 있고 침탄강을 사용할 시 치폭이 3mm줄어들고, 기어 잇수가 1-3개 줄어들고 피치원의 지름이 4-13mm 줄어들어 감속기를 경량화 시킬 수 있다는 것을 시뮬레이션을 통하여 입증되었다.

• Journal of the Korea Convergence Society
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• v.7 no.1
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• pp.177-182
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• 2016

In order that the track vehicle utilized on the purpose of heavy industry and military affair may endure the vehicle body with heavy weight, the link surrounding the mobile wheel is affected with the great force by the load transferred at the vehicle body. This happened force gives rise to a decline in the durability throughout the track. In this paper, the models with the shapes of track pads in common use are designed and the model at which the wear of track pad and the damage of link can be decreased effectively is contrived. Also, by applying this study result to the design of track vehicle, it can contribute to the safe design for damage prevention and durability improvement. It is possible to be grafted onto the convergence technique at the designed factor of pad shape and show the esthetic sense.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.3
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• pp.409-418
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• 1988

Steam turbines, gas turbines, multistage centrifugal compressors are operated over the range of the first critical speed. In these rotors flexible rotor balancing technique is necessary. In such balancing, influence coefficients are measured by rotating a rotor with trial weight. But for the large rotor, the measurement of influence coefficient takes much time and it reduces the cost efficiency. In this paper the new influence coefficient with rotation of rotor is proposed. First the theoretical background of the method is presented and it is applied to the simple flexible rotor model. Then the experiments are performed and the results of presented method are compared with those of analytical method. By using the obtained influence coefficient, balancing of the flexible rotor is performed.

• Journal of Korea Multimedia Society
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• v.11 no.8
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• pp.1146-1159
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• 2008

This paper proposes a method for determining material property of a haptic model which represents the haptic behavior of a target object. This paper also presents a haptic rendering framework. We adapt elastography to obtain the physical property of a target object. One of the key differences between the proposed framework and a traditional method is that the physical property of the target object can be easily set into a haptic model. For evaluating the proposed method, we construct a real-time palpation prototype simulator. In our work, a human liver is selected as a target object and the liver is represented by Shape-retaining Chain Linked Model(S-chain model) for satisfying the real-time performance. We conduct experiments whether a user easily distinguishes abnormal portions from normal portions. From the experimental results, we evaluate that the proposed method provides the discriminable force to users in real-time.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.451-456
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• 2009

In this paper, a virtual force is generated and fed back to the operator to make the teleoperation more reliable, which reflects the relationship between a slave robot and an uncertain remote environment as a form of an impedance. In general, for the teleoperation, the teleoperated mobile robot takes pictures of the remote environment and sends the visual information back to the operator over the Internet. Because of the limitations of communication bandwidth and narrow view-angles of camera, it is not possible to watch certain regions, for examples, the shadow and curved areas. To overcome this problem, a virtual force is generated according to both the distance between the obstacle and the robot and the approaching velocity of the obstacle w.r.t the collision vector based on the ultrasonic sensor data. This virtual force is transferred back to the master (two degrees of freedom joystick) over the Internet to enable a human operator to estimate the position of obstacle at the remote site. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. It is demonstrated by experiments that this collision vector based haptic reflection improves the performance of teleoperated mobile robot significantly.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.69-78
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• 2014

This study deals with the digital policy proposal through the path modeling study on the effect of the strength of weak ties & emotional perception leading to the user's satisfaction, WOM between game users, and the verification on the effect of the emotional real name SNS on the social network game's diffusion. Researcher confirmed that the effect of the strength of weak ties & emotional perception led to the user's satisfaction, WOM of SNG. Even though weak tie, researchers estimate that the users emotionally interact with the real name relation effect of SNS. And effective factors for WOM are not a tie relationship or emotional interactivity of weak tie antecedently but user's satisfaction. As a result, though antecedent factors (weak tie & interactivity) had a positive effect as real name SNS, eventually powerful factor of making buzz was the SNG user's satisfaction. Thus researchers expect the practical policy proposition for government & corporation, which means SNG service providers more carefully manage the service satisfaction for WOM with SNG user's experience.