• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.4
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• pp.277-283
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• 2017

In this study, we investigated how a jumping strategy changes with an increase in the vertical jump height for a resultant ground reaction force (GRF) vector. We expected that the resultant force vector between two sequential motion phases (i.e., countermovement and push-off) of the countermovement jump would significantly change with the vertical jump height to take advantage of the resulting supportive force (i.e., an initial push-off force larger than the body weight) through the countermovement phase. Nine healthy young subjects were instructed to jump straight up to five different height levels ranging from 191 cm to 221 cm, and the kinematic and kinetic data were obtained in regular trials. The results showed that a lower center of mass position and larger resultant force vector were clearly observed in a higher jump, implying that the countermovement strategy changed with the vertical jump height to prepare for sufficient joint deviation and obtain a force advantage for larger push-off work.

• 프린팅코리아
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• v.8 no.6
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• pp.96-97
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• 2009

자신에게 맞는 프론트 엔드(front-end)를 사용하는 것은, 특히 디지털과 오프셋을 모두 운영하고 있지만 제공 선택의 범위 때문에 결정하기 어려운 경우라면, 모든 점에서 이득이 될 수 있다. 오늘날의 디지털 기계는 날렵하고 성능이 좋은 소형의 기계 장치이다. 그렇지만, 디지털 인쇄 장치를 최대한으로 활용하기 위해서는 힘이 아니라 머리가 필요하다. 디지털 작동의 머리 즉, 워크플로우는 매우 중요하다. 가장 현명한 선택을 한다는 것은 항상 기지를 유지한다는 의미이다. 그렇다면, 디지털 하드웨어 및 소프트웨어의 가장 좋은 방향은 무엇인가? 그것은 전적으로 사업의 특성과 목표로 하는 애플리케이션에 달려있다. 자신에게 맞는 것이 저 길 아래에 있는 다른 회사와는 매우 다를 수 있다.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.1
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• pp.46-55
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• 2006

This paper presents the control method for the hybrid actuator comprising a DC motor and an MR brake. Generally, a DC motor as an active actuator has a small power to weight ratio and goes unstable with higher force control gain due to its saturation limit. In order to cope with this instability and make the transparency higher, this paper proposes a hybrid actuator which consists of a DC motor and an MR brake as a passive actuator and its force control method based on network theory. A DC motor actively produces the output corresponding to the signs of the input currents. On the other hand, an MR brake passively resists against the external load independent of the sign changes of the input currents. This characteristics is widely known as 'passive' This paper suggests a force control method based on passivity concept in network theory for the hybrid actuator and verified its performance and stability through the experiments.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.6
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• pp.637-642
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• 2013

In this paper, an analysis results of towing force and towing points which are dominating factors to determine the behavior of towed ship are introduced. The towing force and towing points to achive the desired posture and its position of the towed vessel are derived based on simplified dynamics and linearization method. LQR algorithm for posture control is applied to linearized system and numerical simulation is also executed. Force based on COG(cneter of gravity) and gain of controller to achieve desired posture for target vessel are obtained by using Riccati matrix equation and pseudo inverse matrix is applied to analyze the relation between the derived force and its towing point. Based on this analysis method, towing force need to move the towed vessel from its initial position to target position can be calculated. The towing method including towing point and direction is also considered on this method. Finally, the relation between towing force and towing point is confirmed from the analysis and the results can be applied to arrangement of tug boats during salvage works.

• Journal of Chest Surgery
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• v.33 no.11
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• pp.910-914
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• 2000

Ehlers-Danlos 증후군 중 제4형은 다른 형들과 마찬가지로 피부 손상이 쉽게 오고, 쉽게 멍이 들고, 관절이 잘 휘어지는 등의 신체적인 특징을 가기지만 대혈관을 침범하여 때로는 치명적인 출혈을 일으키기도 한다. 아주 작은 충격이나 힘에도 혈관들이 쉽게 찢어지거나 때로는 심각한 손상을 임기 때문에 수술 적인 치료를 하는데 많은 위험이 있을 수 있고 심지어는 이득을 얻지 못하는 경우도 있다. 저자들은 Ehlers-Danlos 증후군을 동반한 급성 대동맥박리의 성공적인 수술적 치료를 보고하는 바이다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.131-134
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• 1995

The high efficiency and accuracy in machining the die material can be abtained in high speed machining, so it is necessary to analyze the mechanism of high speed cutting process : cutting force, flank wear. The tool dynomometer with high natural frequency is newly developed. With this device, the mechanism of high speed cutting process is investigated according to speed and feedate.

• Korean Architects
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• s.501
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• pp.58-60
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• 2011

인의식 건축사와 가깝게 지내게 된 것은 몇 년이 안 된다. 매사에 열심이고, 이번 원고청탁도 나에게 나타나는 것이 부끄럽다고 극구 사양하는 것을 겨우 인터뷰하였다. 지금은 건축경기가 극히 불투명하여 예전에 설계 좀 한다고 이름이 나 있는 건축사들에게도 힘든 시간이다. 인의식 건축사의 겨우 건축설계에 올인 하는 것은 물론 인테리어, 조경, 조명 등 전문영역으로 치부하여 남에게 외주 주어 버리는 것을 본인이 다하려고 죽을 힘을 다한다. 단순히 경제적으로만 볼 것이 아니라 토탈 디자인 개념에서 그러는 것이다. 부수적으로 경제적인 이득도 있을 것이다 중세시대의 거장들이 미술, 조각, 건축까지 망라하여 관여한 것을 생각하면 실은 아무것도 아니다. 이런 장인정신이 오늘 그가 불경기에도 오뚝이 같이 잘 버텨나가는 증좌다. 그리고 그의 대표작인 된 '덕평휴게소'에 가면 그의 노력이 잘 드러나 있다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.413-418
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• 2005

This paper proposes a measurement method for the surface of micro-parts by using AFM(Atomic Force Microscope). To this end, two techniques are presented to extend the capacity of AFM. First, the measurement range is extended by using an image matching method based on correlation coefficients. To account for the inaccuracy of the coarse stage implemented in AFM's, the image matching technique is applied to two neighboring images intentionally overlapped with each other. Second, a method to measure the shape of relatively large specimen is presented by using the inherent trigger mechanism due to the atomic force. The proposed method is proved effective through a series of experiments.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.6
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• pp.22-30
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• 2005

This paper proposes a measurement method for the surface shape of micro-parts by using an atomic force microscope(AFM). To this end, two techniques are presented: First, the measurement range is expanded by using an image matching method based on correlation coefficients. To account for the inaccuracy of the coarse stage implemented in AFM, the image matching technique is applied to two neighboring images intentionally overlapped with each other. Second, a method to measure the shape of relatively large specimen is proposed that utilizes the inherent trigger mechanism due to the atomic force. The proposed methods are proved effective through a series of experiments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.291-299
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• 2021

This paper presents the control logic for the momentum wheel and gimbals in the CMG system. First, the design of the control logic for the momentum wheel is described in consideration of the power consumption and stability. Second, the design of the control logic for the gimbals considering the resonance of the vibration absorber and stability is explained. Third, the measurement configuration for the force and torque generated by the CMG is described. Fourth, the results of the frequency and time response test of the momentum wheel and gimbals are shown. Last, the measurements of the force and the torque generated through the CMG are explained.