• 대한기계학회논문집
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• 제16권6호
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• pp.1171-1178
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• 1992

본 연구에서는 직접접촉식 열교환기를 이용한 실험을 통하여 열교환기 설계에 가장 중요한 열교환기 단위 체적당 총괄 열전달 계수를 시스템의 작동조건에 따라 구 하여 실제 설계자료로 이용하는 데 그 목적이 있다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.341-348
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• 2001

In this study, nonlinear vibration analysis of the cylindrical orthotropic porous thin plate under V-shaped tension distribution with wire impact damping is considered. We make dynamic model of the plate under the tension using commercial FEM code and reduce the number of its degrees of freedom using dynamic condensation. The dynamic model of wire is obtained as lumped mass model from string equation. And then we analyze the nonlinear vibration of the plate including the impact phenomenon between the plate and the wire using the reduced mass and stiffness matrices of the plate and lumped model of the wire. The contact phenomenon between them can be described by impact contact elements composed of contact stiffness coefficients from Hertzian contact theory and contact damping coefficients from restitution coefficient between them. And we discussed the results of nonlinear vibration analysis for variations of their design parameters.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.547-548
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• 2009

• 한국소음진동공학회논문집
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• 제20권12호
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• pp.1121-1127
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• 2010

Human characteristic responding to idle vibration on passenger vehicle was studied to find if affected by seating posture of passenger. When twelve male subjects are exposed to moderate vertical vibration of 0.224 $m/s^2$ r.m.s. at frequency range from 3 Hz to 40 Hz, it was found that seating posture significantly affects to biodynamical characteristics, apparent mass and apparent eccentric mass, at most range of idle vibration frequency(20~40 Hz). The supported thigh contact on rigid seat showed bigger values in the two biodynamical characteristics than the average thigh contact. The bigger apparent mass and apparent eccentric mass in the seating posture of the supported thigh contact can be assumed more strengthened muscle at the frequency range.

• Journal of Astronomy and Space Sciences
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• 제29권2호
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• pp.145-149
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• 2012

I describe a series of processes, including hierarchical fragmentation, gravitational scattering, Kozai cycles within triple systems, tidal friction and magnetic braking, that I believe are responsible for producing the modest but significant fraction of stars that are observed as contact binaries. I also discuss further processes, namely heat transport, mass transport, nuclear evolution, thermal relaxation oscillations, and further magnetic braking with tidal friction, that influence the evolution during contact. The endpoint, for contact, is that the two components merge into a single star, as recently was observed in the remarkable system V1309 Sco. The single star probably throws off some mass and rotates rapidly at first, and then slows by magnetic braking to become a rather inconspicuous but normal dwarf or subgiant. If however the contact binary was part of a triple system originally-as I suggested above was rather likely-then the result could be a $widish$ binary with apparently non-coeval components. There are several such known.

• Journal of Astronomy and Space Sciences
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• 제22권3호
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• pp.233-242
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• 2005

66개의 근접촉쌍성(이하 NCBb)의 절대물리량과 궤도요소를 여러 목록으로부터 수집 분석하여 여러 물리량 사이의 상관관계와 NCBs의 물리적 특성을 조사하였다 NCBs의 질량비-광도비 관계는 $L_2/L_1{\lapprox}(M_2/M_1)^{1.45}$로 나타났으며 CE형에 더 근접한 특성을 보였다. NCBs의 여러 물리량 사이의 상관관계에 따르면 F형이 A형에 비하여 주성과 반성의 질량, 반경, 광도 및 온도의 차이가 작게 나타났다. NCBs의 H-R도에 따르면 A형이 F형에 비하여 다소 더 진화된 종년주계열(TAMS)에 가까이 나타나고 있다.

• Structural Engineering and Mechanics
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• 제4권3호
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• pp.303-312
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• 1996

The dynamic behavior of an Euler beam with multiple point constraints traversed by a moving concentrated mass, a "moving-force moving-mass" problem, is analyzed and compared with the corresponding simplified "moving-force" problem. The equation of motion in matrix form is formulated using Lagrangian approach and the assumed mode method. The effects of the presence of intermediate point constraints in reducing the fluctuation of the contact force between the mass and the beam and the possible separation of the mass from the beam are investigated. The equation of motion and the numerical results are expressed in dimensionless form. The numerical results presented are therefore applicable for a large combination of system parameters.

• 한국의류학회지
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• 제18권2호
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• pp.180-188
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• 1994

The purpose of this study was to evaluate the effect of basic needs and demographic variables of adult woman on the modesty and aethetics In the selection of clothes. The results of the study were as follows: 1. There are factors which have effect on variables of need. School careers have effect on physical need. Age, marriage status and household type have effect on safty need. Native community and household type have effect on self-esteem. School career, native community, household type and frequency of contact with mass media have effects on need of self-actualizing and native community has effect on the aesthetic need. 2. Physical bleed, self-esteem, self-actualization, safety need, fiequency of contact with mass media, age, native community and income have direct effect on the modesty of clothing. 3. Aethetic and self-actualization need, frequency of contact with mass media and income have direct effect on the aethetics of clothing.

• Tribology and Lubricants
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• 제16권4호
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• pp.289-294
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• 2000

This paper present the contact stresses, which considers the shear stress at the cam and follower interface in the direct acting type valve train system of a high speed engine. To determine the contact condition, the normal contact forces are calculated by using the lumped mass dynamic modeling. The line contact is considered between the cam and follower interface. The variations of dynamic stresses are presented as a function of camshaft rotational angle. Also the effects of various design parameters are investigated.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.870-874
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• 2007

Golf ball spin rate after impact with club is created by the contact force, which is greatly influenced by ball and club mass, material, impact speed, and club loft angle. Previous studies showed that the contact force is determined as the resultant force of the reaction forces normal and tangential to the club face at the contact point. The normal force causes the compression and restitution of the ball, and the tangential force creates the spin. Especially, the tangential force takes either positive or negative values as the ball rolls and slides along the club face during impact. Although the positive and negative tangential forces are known to create and reduce the back spin rate, respectively, the mechanism of ball spin creation has not yet been discussed in detail. It is shown in this work that the linear impulse of the tangential force is directly related to generation of back spin rate of golf ball. The linear impulse can be calculated from the tangential force, which depends upon many factors such as ball and club mass, material, impact speed, and club loft angle. In this research, the influence of the contact force between golf club and ball is investigated to analyze the mechanism of impact. For this purpose, the contact force and the contact time at impact between golf club head and ball are computed using FEM.