• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2227-2229
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• 2003

Using the gyro effect, Balance Beam Controller is developed with Samsung Corporation. Balance Beam Controller is possible to control the position of an object in air by controlling the attitude of inner gimbal. But in the unknown load inertia case, even a skilled worker it is not easy to operate a Balance Beam. That is caused by the difficulty to estimate the load inertia. If the amount of the gimbal operation is set excessively with a wrong load estimation, it can often cause accidents. To solve this problem, the control function which is revolving with velocity of the revolution has to be added to developed equipment. In this research, we analyze the characteristics of a Balance Beam(the smaller load inertia, the bigger force of restitution) using the angular velocity sensor, and present constant velocity revolving controller with estimating value of the load using this moving characteristics.

• 대한기계학회논문집
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• 제15권1호
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• pp.1-10
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• 1991

본 연구에서는 고속 대변형 탄소성 변형 과정을 해석할 수 있는 프로그램(NET )을 개발하고 이것을 실린더 및 링 성형 문제에 적용하여 마찰 및 관성 효과가 변형 거동에 미치는 영향을 규명하여 보았다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
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• pp.309-315
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• 1996

An analysis is presented on the stability of elastic cantilever column subjected to uniformly distributed follower forces as to the influence of the elastic restraints and a tip mass at the free end. The elastic restraints are formed by both the translational and the rotatory springs. For this purpose, the governing equations and boundary conditions are derived by using Hamilton's principle, and the critical flutter loads and frequencies are obtained from the numerical evaluation of the eigenvalue functions of this elastic system. The added tip mass increases as a whole the critical flutter load in this system, but the presence of its moment of inertia of mass has a destabilizing effect. The existence of the translational and rotatory spring at the free end increases the critical flutter load of the elastic cantilever column. Nevertheless their effects on the critical flutter load are not uniform because of their coupling. The translational spring restraining the end of cantilever column decreases the critical flutter load by coupling with a large value of tip mass, while by coupling with the moment of inertia of tip mass its effect on the critical flutter load is contrary. The rotatory spring restraining the free end of cantilever column increases the critical flutter load by coupling with the tip mass, but decreases it by coupling with the moment of inertia of tip mass.

• 소음진동
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• 제7권1호
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• pp.91-97
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• 1997

An analysis is presented on the stability of an elastic cantilever column having the elastic restraints at its free end, carrying an added tip mass, and subjected to uniformly distributed follower forces. The elastic restraints are formed by both a translational spring and a rotatory spring. For this purpose, the governing equations and boundary conditions are derived by using Hamilton's principle, and the critical flutter loads and frequencies are obtained from the numerical evaluation of the eigenvalue functions of this elastic system. The added tip mass increases as a whole the critical flutter load of the elastic cantilever column, but the presence of its moment of inertia of mass has a destabilizing effect. The existence of the translational and rotatory springs at the free end increases the critical flutter load of the elastic cantilever column. Nevertheless, their effects on the critical flutter load are not uniform because of their coupling. The translational spring restraining the free end of the cantilever column decreases the critical flutter load by coupling with a large value of tip mass, while by coupling with the moment of inertia of tip pass its effect on the critical flutter load is contrary. The rotatory spring restraining the free end of the cantilever column increases the critical flutter load by coupling with the tip mass, but decreases it by coupling with the moment of inertia of the tip mass.

• Structural Engineering and Mechanics
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• 제67권2호
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• pp.155-163
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• 2018

The Early-age construction loading and changing properties of concrete, especially in the multi-story structures can affect the slab deflection, significantly. Based on previously conducted experiment on eight simply-supported one-way slabs this paper investigates the effect of concrete type, fiber type and content, loading value, cracking moment, ultimate moment and applied moment on the instantaneous deflection of Self-Compacting Concrete (SCC) slabs. Two distinct loading levels equal to 30% and 40% of the ultimate capacity of the slab section were applied on the slabs at the age of 14 days. A wide range of the existing models of the effective moment of inertia which are mainly developed for conventional concrete elements, were investigated. Comparison of the experimental deflection values with predictions of the existing models shows considerable differences between the recorded and estimated instantaneous deflection of SCC slabs. Calculated elastic deflection of slabs at the ages of 14 and 28 days were also compared with the experimental deflection of slabs. Based on sensitivity analysis of the effective parameters, a new model is proposed and verified to predict the effective moment of inertia in SCC slabs with and without fiber reinforcing under two different loading levels at the age of 14 days.

• Geomechanics and Engineering
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• 제34권6호
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• pp.649-664
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• 2023

Structural inertial interaction is a representative the effect of dynamic soil-foundation-structure interaction (SFSI), which leads to a relative displacement between soil and foundation, period lengthening, and damping increasing phenomena. However, for a system with a significantly heavy foundation, the dynamic inertia of the foundation influences and interacts with the structural seismic response. The structure-to-foundation mass ratio (MR) quantifies the distribution of mass between the structure and foundation for a structure on a shallow foundation. Although both systems exhibit the same vertical factor of safety (FS_v), the MR and corresponding seismic responses attributed to the structure and foundation masses may differ. This study explored the influence of MR on the permanent deformation and seismic response of soil-foundation-structure system considering SFSI via numerical simulations. Given that numerous dimensionless parameters of SFSI described its influence on the structural seismic response, the parameters, except for MR and FS_v, were fixed for the sensitivity analysis. The results demonstrated that the foundation inertia of heavier foundations induced more settlement due to sliding behavior of heavily-loaded systems. Moreover, the structural inertia of heavier structures evidently exhibited foundation rocking behavior, which results in a more elongated natural period of the structure for lightly-loaded systems.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.203-210
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• 2003

A simulation study was carried to analyze the vehicle fuel consumption on component basis. Experiments was also carried out to identify the simulation results, under FTP-75 Hot Phase driving conditions. and arbitrary driving conditions. A good quantitative agreement was obtained. Based on the simulation, fuel energy was used in pumping loss(3.7%), electric power generation(0.7%), engine friction(12.7%), engine inertia(0.7%), torque converter loss(4.6%), drivetrain friction(0.6%), road-load(9.2%), and vehicle inertia(13.4%) under FTP-75 Hot Phase driving conditions. Using simulation program, the effects of capacity factor and idle speed on fuel consumption were estimated. A increment of capacity factor of torque converter resulted in fuel consumption improvement under FTP-75 Hot Phase driving conditions. Effect of a decrement of idle speed on fuel consumption was negligible under the identical driving conditions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.670-676
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• 2004

In this paper, a modeling method for the vibration analysis of rotating structures composed of beams and shells employing multi-reference frames is presented. The rotary inertia effect and the geometric stiffening effect that results from centrifugal inertia force we considered for beams and shells with lumped mass model. In most previous studies, single reference frame has been employed for the vibration analysis. In the present study, a modeling method employing multi-reference frames is presented and the effects of employing multi-reference frames on the analysis accuracy are investigated through solving numerical examples.

• 경영과정보연구
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• 제37권4호
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• pp.195-217
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• 2018

무행동 관성효과는 과거의 매력적인 기회를 놓친 사람들이 이후 할인(세일)기회가 주어져도 그것을 얻기 위한 행동을 하지 않는 현상을 말한다. 본 연구의 기본 목적은 이런 무행동 관성효과가 소비목표에 따라 쾌락적인 소비목표를 가지는 경우와 실용적인 소비목표를 가질 때를 구분하여 예상된 행동후회와 예상된 무행동 후회 및 구매의도에 어떠한 영향을 미치는지 규명하고자 하였다. 이는 소비자의 개인적 성향이 다르게 나타나기 때문에 습관적 구매성향과 극대화 성향이 무행동 관성에 영향을 주는 요소가 될 것임을 예상하였다. 연구목적 달성을 위하여 시나리오를 사용하여 실험을 진행하였으며 연구결과 쾌락적 소비목표를 가진 소비자의 경우 습관적으로 동일한 브랜드를 구매하는 소비자에서 예상된 행동후회와 예상된 무행동 후회 수준이 더 높았다. 그리고 극대화 성향의 경우 예상된 행동후회에 대해서는 실용적 소비목표와 쾌락적 소비목표에 따른 차이가 발견되지 않았다. 반면 첫 번째 할인(세일)기회를 놓친 후 두 번째 할인(세일)기회에 구매를 하지 않는 후회수준인 예상된 무행동 후회에서는 차이가 나타났다. 따라서 소비목표가 쾌락적인 경우에는 습관적 구매성향에 따라 무행동 관성행동이 나타났으나 실용적 소비목표에서는 무행동 관성효과가 강하게 나타나지 않았다. 이는 실용적 소비목표의 경우 소비에 대한 정당화가 상대적으로 적기 때문이라고 설명된다. 반면 극대화 성향의 소비자의 경우 쾌락적 소비목표에서보다 실용적 소비목표에서 예상된 무행동 후회에 더 강한 후회를 한다는 것을 알 수 있었다. 또한 구매의도와 관련해서는 쾌락적 소비목표를 가진 소비자들에게서만 구매의도가 있는 것으로 나타났다. 결국 연구결과를 통해 무행동 관성행동이 나타나는 것은 제품이나 서비스가 어떠한 소비목표를 가지고 소비되는지 개인적인 성향에 따라 고려하는 것이 필요하다. 이러한 결과에 따른 몇 가지 이론적 및 실무적 시사점을 논의하였다.

• 대한기계학회논문집A
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• 제21권10호
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• pp.1580-1588
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• 1997

A modeling method for the flapwise bending vibration of a rotating cantilever beam which has small slenderness ratio is presented in this paper. It is shown that as the slenderness ratio decreases the shear and rotary inertia effects increase. Such effects become critical for the accurate estimation of the natural frequencies and modeshapes, especially higher frequencies and modes, as the angular speed increases. It is also shown that the flapwise bending natural frequencies are higher than the chordwise bending natural frequencies. The discrepancy between first natural frequencies are especially significant when the hub radius ratio is small.