• 대한관절경학회:학술대회논문집
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• 대한관절경학회 2008년도 춘계 공동 학술대회
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• pp.31-31
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• 2008

• Journal of Mechanical Science and Technology
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• 제17권8호
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• pp.1133-1139
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• 2003

In this paper, a numerical algorithm for the kinematic analysis of a multi-link five-point suspension system is presented. The kinematic analysis is carried out in terms of the rectangular Cartesian coordinates of some defined points in the links and at the joints. Geometric constraints are introduced to fix the relative positions between the points belonging to the same rigid body. Position, velocity and acceleration analyses are carried out. The presented formulation in terms or this system of coordinates is simple and involves only elementary mathematics. The results of the kinematic analysis are presented and discussed.

• 한국정밀공학회지
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• 제16권6호
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• pp.148-159
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• 1999

A numerical method is presented for the dynamic analysis of spur gears rotating with very high angular speeds. For an efficient computation each gear is assumed to consist of a rotating rigid disk and an elastic tooth having mass, and finite element formulations are used for the equations of motion of the tooth. The geometric constraint is imposed between the rigid disk and the elastic tooth to fix them, and contact condition is imposed between the meshing teeth of the gears. At each iteration of each time step the Lagrange multiplier and contact force are revised by using the constraint error vector, and then the whole equations of motion are time integrated with the given Lagrange multiplier and contact force. For the accurate solution the velocity and acceleration constraints as well as the displacement constraint are satisfied by the monotone reductions of the constraint error vectors. Computing procedures associated with the iterative schemes are explained and numerical simulations are conducted with the spur gears.

• 대한관절경학회지
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• 제11권2호
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• pp.134-138
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• 2007

Brodie 농양은 빈도가 흔하지 않고, 독성이 적은 원인균에 의해 발생하는 아급성 혹은 만성 골수염의 국소형으로 소아나 청소년의 하지 장골 특히 경골의 골간단과 골단 부위에 호발하나 성인에서도 발생할 수 있다. 수술적 치료시 병변의 위치가 근위 경골 골간단 후방에 위치한 경우 개방적 소파술로는 병소 접근이 어렵고 신경 혈관 손상 및 주위 조직 오염의 위험성이 있다. 본원 정형외과에서 48세 남자에서 발생한 경골 근위부 골간단 후방부의 Brodie 농양을 전방 십자 인대 재건술시 사용하는 표적 기구(Rigid fix system, Mitek, Johnson & Johnson, Norwood, MA)를 이용하여 병소에 손쉽고 정확하게 삽입구를 만들어 내시경 시야 하에서 염증 및 육아 조직을 제거하여 치료한 경험이 있어 이를 문헌 고찰과 함께 보고하고자 한다.

• 한국생산제조학회지
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• 제21권3호
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• pp.425-432
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• 2012

This paper investigates shape design processes of two implant systems for bone fracture treatment ; Bone plate and Interlocking nail system. These systems can directly fix fractured human bones by surgical operations. The bone plates consist of various shaped plates and implant screws for fixation of fractured human bones with various manual instruments allowing to handle them. The material corresponds to titanium alloy Ti6Al4V because it is harmless material for human body as well as significantly rigid. This system has to be suitably rigid as well as manually bended in orthopedic surgery operations. The Interlocking nail system is a kind of nail implanted inside fractured human bones. The shapes of these systems have to be suitably designed in order to endure various loads as well as avoid any damages. If various shaped prototypes would be fabricated and tested to design the optimal shapes, optimal shapes could be obtained but very long time and expensive costs must be required. In this paper finite element method was applied into these systems. Under various boundary conditions a series of structural analysis was conducted by using ANSYS. Finally important shape factors could be determined on the basis of the analysis results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1361-1366
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• 2007

Forging for spring cup of engine valve was investigated in this study. New method is needed to reduce cost and development lead time required to fix forming process of new product, that eventually can provide die, metal flow and forming loads with high confidence level. FEM could provide required detail information that could reduce trial error in advance before the actual production. By using the rigid-plastic finite element simulation, possibilities of improving former research were explored. Results generated by FEM could foresee expected material deformation in advance and made possible new forming process successfully.

• Journal of Mechanical Science and Technology
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• 제17권12호
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• pp.1961-1968
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• 2003

In this paper, an efficient numerical algorithm for the kinematic analysis of the standard MacPherson suspension system is presented. The kinematic analysis of the suspension mechanism is carried out in terms of the rectangular Cartesian coordinates of some defined points in the links and at the kinematic joints. Geometric constraints that fix the distances between the points belonging to the same rigid link are introduced. The nonlinear constraint equations are solved by iterative numerical methods. The corresponding linear equations of the velocity and acceleration are solved to yield the velocities and accelerations of the unknown points. The velocities and accelerations of other points of interest as well as the angular velocity and acceleration of any link in the mechanism can be calculated.

• 대한치과보철학회지
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• 제55권4호
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• pp.389-393
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• 2017

목적: 본 연구의 목적은 탄성력이 높게 개발된 레진의 굽힘 강도를 평가하고, resin wire splint (RWS)와 유연성을 비교 평가하는 것이다. 재료 및 방법: 세가지 레진 G-aenial flo (GA, GC), Superbond (SB, Sun medical), G-fix (GF, GC)의 세 점 굽힘 강도는 ISO4049/2000에 따라 진행하였다. GA, SB, GF를 이용한 세개의 RS군과 GA와 교정용 016" SS wire를 이용한 RWS군간의 치아 동요도 비교는 영구치 모형을 이용하였다. 상악좌측중절치에 3도의 동요를 부여하고, 치아의 수평적인 동요도를 splint 전후에 각 3회씩 periotest vale로 평가하였다. Splint 전후 periotest value는 splinting 효과로 환산하여 평가하였다. 통계적인 평가는 one-way ANOVA와 turkey HDS test를 이용하였다(${\alpha}=.05$). 결과: SB와 GF가 GA에 비해 낮은 굴곡강도를 보였으나, 세가지 RS군은 RWS에 비해 높은 splinting 효과를 나타내었다 (P < .05). 결론: 제한된 본 연구에서 사용된 재료와 상관없이 RS는 RWS에 비해 높은 견고성을 보였으며, 이는 탈구치아 치료를 위한 flexible splint에 부적합한 것으로 보인다.

• 한국지반신소재학회논문집
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• 제11권4호
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• pp.27-35
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• 2012

국내에 적용되고 있는 블록식 보강토 옹벽의 전면벽체는 보강재의 고정 및 뒷채움재의 유실방지 역할을 하지만, 벽체에 작용하는 하중에 대한 역학적 기능은 부족하다. 보강토체를 구성하는 벽체에 휨 및 전단에 대한 저항 성능을 부여하기 위하여 개발된 강성벽 일체형 보강노반은 다양한 장점에도 불구하고, 기존 공법과 비교하여 경제성 및 시공성 측면에서 단점이 부각되어 현장에의 적용은 미루어져 왔다. 본 연구에서는 강성벽 일체형 보강노반의 국내 적용성 향상을 목적으로 강성벽의 성능은 확보하면서 경제성 및 시공성을 향상시키기 위한 보강재 연직 배치 간격 및 길이 변화가 보강토체 전체의 거동에 미치는 영향을 평가하였다. 이를 위하여 강성벽을 갖는 1/10 축소모형 보강토체 및 높이 3m의 실내 실대형 시험체를 조성하고, 모사 열차하중 하에서의 변형 특성을 평가하였다. 시험 결과 비록 짧은 보강재를 사용함에도 불구하고 강성벽 보강노반에서 벽체 수평 발생변위 및 침하는 허용한계 수준 이하이었으며, 보강재 연직 배치간격이 30cm에서 40cm로 증가하여도 사용성 측면에서의 성능 수준에는 큰 변화가 없는 것을 확인할 수 있었다.

• 공학교육연구
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• 제23권3호
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• pp.32-40
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• 2020

A new moment of inertia experiment apparatus different from the existing one has been developed, which does not require deformation of a sample in order to fix it to the apparatus. This new experiment apparatus was able to experiment with constant-shaped objects that did not deform the samples, so that it enabled them for conducting an experiment which is close to an ideal rigid model dealt in the general physics course. The new experimental apparatus was easy and accurate in measuring the physical quantity by using the experimental principle of physical pendulum. In the results of the measurement of the moments of inertia of the six samples, all measurements were made to be accurate enough to measure with very small errors within 1%. In addition, it has been found to be useful as an experiment apparatus to understand the concept of the moment of inertia and to prove the formula for moment of inertia. Therefore, if the new moment of inertia experiment apparatus developed in this study is used in students' experiments, it is expected that students will be able to greatly increase their understanding of the concept of moment of inertia.