• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1992.11a
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• pp.1-12
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• 1992

시일은 상대 접촉운동하는 기계장치에서 밀봉유체의 누설을 막고, 이물질 및 수분의 침투를 방지하기 위하여 사용되는 기계요소로써 베어링에 사용되는 접촉식 고무시일은 작은 설치공간, 간편한 조립방법, 저렴한 가격 등의 장점을 갖고 있다. 최근 기계공업 발전에 따라 기계 장치에 요구되고 있는 기동 및 운전조건이 고속, 고압력, 고온 및 극저온 등 가혹해져 감에 따라 정밀도를 유지$\cdot$향상시키면서 원활한 밀봉기능을 수행하는 시일 개발에 대한 중요성이 크게 부각되고 있다. 볼 타입 밀봉 베어링의 윤활제로는 그리이스가 가장 많이 사용되고 있고, 시일 재질로는 고무계통인 러리 사용되고 있다. 본 연구에서는 시일성능이 비교적 우수한 축방향 접촉식 고무 시일의 접촉력에 관한 이론적 및 실험적 연구를 하고 각각을 비교 검토하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.12
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• pp.2261-2267
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• 1992

The equations are derived for the evaluation of the axial contact force. The contact forces for rubber seals are analyzed as a function of the ratio of real contact length, the thickness of seal lip, the inclined angle of seal lip, and the interference between the edge of seal lip and the rotating inner ring. The design data for rubber seals are presented in terms of the ratio of real contact length, initial inclined lip angle, lip thickness and the interference. The calculated results show that the deflected interference and the circumferential stress cause considerable change of contcat forces for the low sealed pressure.

• Tribology and Lubricants
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• v.25 no.6
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• pp.404-408
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• 2009

In this paper, the relationship between the material removal rate and the interfacial mechanical properties at particle-surface contact situation, which can be seen in an abrasive machining process using micro/nano-sized particles, was discussed. Friction and stiffnesses were measured experimentally on an atomic force microscope (AFM) by using colloidal probes which have a silica colloid particle in place of tip to simulate a particle-flat surface contact in an abrasive machining process. From the experimental investigation and theoretical contact analysis, the interfacial contact properties such as lateral stiffness of contact, friction, the material removal rate were presented with respect to some of material surfaces and the relationship between the properties as well.

• Korean Journal of Culture and Social Issue
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• v.22 no.2
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• pp.203-222
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• 2016

Previous research has demonstrated that imagined contact is useful to reducing prejudice against minorities (e.g. Turner & Crisp, 2010). In this research, we investigated whether imagined contact increases attraction to physically unattractive women, and whether this effect is moderated by perceiver's physical attractiveness and appearance orientation in romantic relationships. Single male participants (n = 98) responded to items assessing their physical attractiveness and appearance orientation, and then were randomly assigned to one of the two conditions. In the imagined contact condition, participants were told to imagine communicating with a physically unattractive woman and come up with some interesting things about her. In the control condition, participants were told to simply imagine a physically unattractive woman. Next, participants saw a picture of a physically unattractive woman and rated her likeability, perceived attractiveness, and willingness to ask her out, which were averaged to form the composite measure of attraction. We found a significant main effect of imagined contact, as expected. This main effect was moderated by appearance orientation, but not by perceivers' physical attractiveness. The effect of imagined contact was significant among those low in appearance orientation, but not among those high in appearance orientation.

• Journal of the Korea Construction Safety Engineering Association
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• v.3 no.3 s.9
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• pp.10-15
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• 1993

• 전기의세계
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• v.27 no.5
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• pp.55-56
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• 1978

(차례) 1.고전계하에 있어서 절연액체의 전기전도 및 절연파괴의 이론 2.고분자의 접촉대전

• Journal of the Korean Society for Railway
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• v.17 no.1
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• pp.14-18
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• 2014

Wheel/rail contact is a significant problem in railway dynamics. In this paper, the wheel/rail contact is examined analytically and numerically as a contact problem between two cylinders where torque and friction have effect. Furthermore, the contact of a real wheel and rail is investigated numerically where the normal and shear force act. This study demonstrates that the wheel/rail contact is a process that generates traction force through creep where rolling and sliding occurs simultaneously depending on the shape of the wheel and rail, and the friction coefficient between them.

• The Journal of Korea Robotics Society
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• v.3 no.2
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• pp.146-153
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• 2008

본 논문에서는 인간 운동 제어 이론과 기계학습을 기반으로 하여 로봇의 접촉 작업 수행을 위한 새로운 운동 학습 전략을 제시하였다. 성공적인 접촉 작업 수행을 위한 본 연구의 전략은 강화학습 기법을 통하여 최적의 작업 수행을 위한 임피던스 매개 변수를 찾는 것이다. 본 연구에서는 최적의 임피던스 매개 변수를 결정하기 위하여 Recursive Least-Square (RLS) 필터 기반 episodic Natural Actor-Critic 알고리즘이 적용되었다. 본 논문에서는 제안한 전략의 효용성을 증명하기 위해 동역학 시뮬레이션을 수행하였고, 그 결과를 통하여 접촉작업에서의 작업 최적화 및 환경이 가지는 불확실성에 대한 적응성을 보여 주었다.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.74-79
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• 2008

In this study, impact transient responses of (Graphite/Epoxy) laminated composite subjected to low-velocity impact are investigated using a finite element method. Dynamic von-Karman plate equations considering large deflection of plate are modified to include the effect of transverse shear deformations as in Mindlin plate theory and also the rotary inertia effect is considered. The convergence of transient responses is used contact law established through the statical indentation test. We investigate displacements, contact forces and strains by thickness variation of various laminated composite. We compare and analyze each results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.1
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• pp.99-106
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• 2011

In this study, the dynamic contact of a catenary system is analyzed by using the finite element method. We derive the equations of motion for the catenary system by taking into consideration tension on the catenaries. After establishing the weak form, they are spatially discretized with beam elements. Then, we analytically calculated the wave propagation speed for a string, bar, beam, and the catenaries subjected to tension. Further, finite element computer program for contact dynamic analyses is developed. Finally, we analyze the wave propagation response corresponding to the moving load to the contact line are calculated.