• Journal of the Korean Society of Safety
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• v.12 no.3
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• pp.178-184
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• 1997

Many mathematical techniques have been developed to determine the muscle forces and force distribution in biomechanical human model, because it is so important to understand internal forces resisting external loading. However, a three-dimensional mathematical model of wrist joint, which is essential to develop solid modeling and artificial wrist joint, has not been well developed. This study proposed to define three-dimensional mathematical model of distal radius and ulna of the human wrist and to develop a detailed two-dimensional finite element through comparisons to existing analytical models and experimental tests. This mathematical model were accurately recreated, allowing the internal tendon force as well as force transmission and distribution through the distal radios and ulna during dynamic loadings. The results found in this study indicate and support the findings of other investigator that cyclic loading condition results in higher compression force on distal radius and ulna and may be source of wrist disorder.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.164-168
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• 2001

The motion of a ship advancing in regular waves is analyzed in the time-domain using the convolution integral of the radiation forces. The memory effect functions and infinite frequency added masses are obtained from the solution of the three dimensional improved Green integral equation in the frequency domain by making use of the Fourier transformation. The ship motions in regular waves have been calculated by both the time and frequency domain methods. It has been shown that they agree very well with each other. The present time-domain method can be used to predict the time histories of unsteady motions in irregular waves. It can also be used to calculate the hydrostatic and Froude-Krylov forces over the instantaneous wetted surface of the ship hull to predict large ship motions, in a practical sense, advancing in large amplitude waves.

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.75-77
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• 2004

본 논문에서는 레그 익스텐션 기구의 안정성을 평가하기 위하여 3차원 유한요소 해석 코드인 ANSYS를 활용하여 구조해석을 실시하였다. 레그 익스텐션 기구를 제작함에 있어서 기존의 기구를 보완하고 운동효과의 향상, 안정성을 고려하여 설계하였다. 또한 레그 익스텐션 기구의 회전봉의 각도를 $0^{\circ}\~360^{\circ}$까지 회전가능하게 설계하여 운동하는 사람의 운동 강도를 조절할 수 있는 새로운 기구를 설계하였다.

• Annual Conference of KIPS
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• 2004.05a
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• pp.765-768
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• 2004

본 논문에서는 2차원 동영상을 SDRAM을 이용하여 실시간 3 차원 입체영상으로 변환하는 장치를 설계 및 구현하였다. 2차원 동영상에서 운동시차를 추출하여 서로 다른 원근 깊이를 갖는 입체영상을 실시간으로 생성하여 기존의 실시간 입체영상 변환기에서 물체의 운동방향과 속도에 제한은 받는 단점을 개선하였다. 본 논문에서는 깊이의 지각요인을 소개하고 기존 실시간 변환방법과 제안한 입체영상 변환 방법의 원리에 대해 설명하였다. 그리고 실시간 영상 처리를 위해 설계한 SDRAM 컨트롤러와 구현한 변환기의 성능을 기술한다.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.3
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• pp.47-53
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• 2001

When a ship advancing in waves is subjected to impact forces or irregular forces, the motion analyses for ship are convenient for being calculated in the time domain. The added mass, wave damping coefficients, wave exciting forces and mean drift forces are calculated by 3-Dimensional panel method used the translating pulsating Green function in the frequency domain and the motion equations which are considered by the memory effect due to waves are numerically solved by using the Newmark-$\beta$ method in the time domain. The motion analyses are carried out for a Series 60($C_B=0.7$) moving in irregular waves. The items of calculation are 6-degree motions, accelerations at the fore and after position, numbers of deck wetness and numbers of exposure at ship-bottom, etc. Moreover, the thrust addition in waves is examined by considering the time mean drift forces in the motion equations of time domain.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.167-167
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• 2002

• Journal of the Society of Naval Architects of Korea
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• v.30 no.2
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• pp.86-97
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• 1993

A numerical method is developed for the nonlinear motion of two-dimensional wedges and axisymmetric-forced-heaving motion using Semi-Largrangian scheme under assumption of potential flows. In two-dimensional-problem Cauchy's integral theorem is applied to calculate the complex potential and its time derivative along boundary. In three-dimensional-problem Rankine ring sources are used in a Green's theorem boundary integral formulation to salve the field equation. The solution is stepped forward numerically in time by integrating the exact kinematic and dynamic free-surface boundary condition. Numerical computations are made for the entry of a wedge with a constant velocity and for the forced harmonic heaving motion from rest. The problem of the entry of wedge compared with the calculated results of Champan[4] and Kim[11]. By Fourier transform of forces in time domain, added mass coefficient, damping coefficient, second harmonic forces are obtained and compared with Yamashita's experiment[5].

• Proceedings of the KSCN Conference
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• 2003.11a
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• pp.1063-1063
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• 2003

본 연구는 중학생들의 음료기호와 빈도 등에 따른 음료 섭취 실태를 조사하기 위하여 실시하였다. 전주시에 재학하고 있는 중학생으로서 남학생 303명, 여학생 276명을 조사 대상으로 설문지 조사를 실시하였다. 음료섭취의 빈도와 이에 영향을 주는 요인은 다음과 같다. 물은 하루 평균 8.55회 섭취하였으며, 우유 및 요구르트 3.01회, 스포츠 음료는 2.13회, 탄산음료는 1.93회, 과일 및 야채 쥬스는 일주일에 1회 섭취하는 것으로 나타났다. 남학생이 여학생보다 탄산음료 및 스포츠음료를 더 선호하는 것으로 나타났으나, 물과 우유 및 쥬스와 전통음료에서는 남학생과 여학생이 유의적인 차이를 보이지 않았다. 학생들은 식사시 주로 물을 마시는 것으로 나타났으며, 그 다음으로 우유를 마시는 것으로 나타났다. 운동 실태에 따른 음료의 섭취는 규칙적인 운동이나 3시간 이상 운동 시 1시간 이하 운동시보다 탄산음료 또는 스포츠음료 및 우유와 요구르트를 선호하는 것으로 나타났다. 음료를 마시는 때는 주로 운동시였고 그 다음으로 쉬는 시간에 스낵과 함께 마시는 것으로 나타났다. 본 연구의 결과 잘못된 음료섭취에 대한 학생과 학부모를 대상으로 영양교육이 필요하며 학교차원에서의 정책적인 접근이 필요하다고 사료된다.

• The KIPS Transactions:PartB
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• v.15B no.2
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• pp.103-112
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• 2008

Image-based motion capture technology is often used in making realistic computer animation. In this paper we try to implement image-based motion rendering by fixing a camera to a PC. Existing image-based rendering algorithms have disadvantages of high computational burden or low accuracy. The former disadvantage causes too long making-time of an animation. The latter disadvantage degrades reality in making realistic animation. To compensate for those disadvantages of the existing approaches, this paper presents an image-based motion rendering algorithm with low computational load and high estimation accuracy. In the proposed approach, an incremental motion rendering algorithm with low computational load is analyzed in the respect of optimal control theory and revised so that its estimation accuracy is enhanced. If we apply this proposed approach to optic motion capture systems, we can obtain additional advantages that motion capture can be performed without any markers, and with low cost in the respect of equipments and spaces.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.3
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• pp.91-96
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• 2006

The aim of this paper is to clarify the structural compliance of the constrained spatial flexible manipulator and to develop the force control by using the compliance of the links. Using the dependency of elastic deflections of links on contact force, vibrations for constrained vertical motion have been suppressed successfully by controlling the position of end-effector. However, for constrained horizontal motion, the vibrations cannot be suppressed by only controlling position of end-effector. We present the experimental results for constrained vertical motion, and constrained horizontal motion. Finally, a comparison between these results is presented to show the validity of link compliance.