• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.69-72
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• 2002

섬유산업은 fiber로부터 시작하여 yarn, fabric을 거쳐 최종 섬유제품인 clothing을 생산하는 긴 stream을 가지고 있으며, 이와 같이 여러 단계의 공정을 거치는 가운데 섬유물은 새로운 형태를 가지게 되며 부가가치가 형성된다. 특히 garments manufacturing 공정에는 fusing press기가 사용되는데 이 방식은 같은 각속도와 지름을 가진 cylinder로 구동되는 두 개의 상하 벨트구동기구와 내부에 열전식 heather로 구성되어 상하 벨트의 내부로 원단과 심지를 통과시키며 열을 가함으로써 원단과 심지를 접착시킨다. (중략)

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.73-76
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• 2002

최근 링 정방기의 생산속도 증가로 인해 사절 및 사물성에 큰 영향을 미치는 정방장력의 중요성이 더욱 커지고 있다. 링 정방장력은 스핀들 회전수, 트래블러 중량, 링직경, 콥 직경 등과 같은 공정인자와 링 레일 상하운동에 따른 벌룬 높이, 얀 가이드에서의 실 굴절각도, 콥의 권취 반경 및 공기저항 등에 의해서도 영향을 받게 된다[1]. 이와 관련하여 링 정방장력 해석[2], 정방 공정인자가 정방장력에 미치는 영향[3] 및 정방 공정인자가 방적사 물성에 미치는 영향[4] 등의 연구가 많이 이루어져 왔다. (중략)

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.1173-1174
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• 2023

Shock Absorber 는 Suspension 부품 중 하나로 감쇠력을 통해 스프링의 수축을 제어함으로써 차량의 승차감 및 안정성을 향상시키는 장치이다[1]. 그러나, 스프링의 상하운동을 억제하기 위해 Shock Absorber 가 압축·인장 됨으로써 소음이 발생하여 탑승객을 불편하게 한다. 본 논문에서는 이에 대한 계측을 통해 원인을 파악하고 NVH 를 개선하여 승차감 향상을 도모한다.

• 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].

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.6-13
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• 2006

Aerodynamic characteristics for two-dimensional cyclic motion profile of flapping airfoil in low Reynolds number flows are investigated. Plunging motion and lead-lag motion in the two dimensional space with different plunging and lead-lag amplitudes are combined to cyclic motion profile and the flow around the airfoil is simulated. Present result shows that the improved aerodynamic efficiencies for a given flapping airfoil by adding periodic lead-lag motion of airfoil rather than the pure plunging case. The thrust coefficient and lift coefficient are compared with each cycle during the flapping period and aerodynamic characteristics are obtained on upstroke motion and downstroke motion.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.97-98
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• 2007

본 논문에서는 운동시간과 칼로리 소모량, 운동시신체운동정도를 3축가속도 센서를 이용하여 측정하는 건강밴드를 설계 하였다. 건강관리를 위해 하는 운동은 많은 양의 운동을 하는 것 보다 규칙성 건강을 관리를 해야 한다. 주거환경의 변화가 친환경적으로 되는 지금 체육시설을 이용하지 않고 쉽게 집 주변에서 운동을 원하는 사람이 많아지고 있기 때문에 건강밴드를 설계하여 보다 쉽게 규칙성 있게 도와주는 운동 보조 시스템을 설계 하여 각 운동별로 센서의 데이터를 측정하였다. 데이터론 측정한 결과 걷기, 조깅, 줄넘기의 3축가속도 센서의 측정간은 걷기에서는 X축의 센서의 변화량이 다른 축의 변화보다 변화량이 많이 심하였고 조깅의 경우 X, Y, Z축의 변화량이 전체적으로 걷기보다 변화가 많았다. 줄넘기에서는 걷기, 조깅과는 다르게 신체의 움직임이 상하로 많이 있는 운동이기 때문에 Y, Z축의 변화량이 X축의 변화량 보다 많이 측정되었다. 이러한 결과를 바탕으로 본 연구의 결과는 운동별 신체의 사용량 측정에 이용이 가능하다.

• Journal of Ocean Engineering and Technology
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• v.27 no.4
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• pp.76-82
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• 2013

Motion reduction of an offshore structure at resonant frequency is essential for avoiding critical damage to the topside and mooring system. A damping plate has a distinct advantage in reducing the motion of a floating structure by increasing the added mass and the damping coefficient. In this study, the heave motion responses of a circular cylinder with an impermeable and a permeable damping plate attached at the bottom of the cylinder were investigated thru a model test. The viscous damping coefficients for various combinations of porosity were obtained from a free-decay test by determining the ratio between any pair of successive amplitudes. Maximum energy dissipation occurred at a porous plate with a porosity P = 0.1008. Experimental results for regular and irregular waves were compared with an analytical solution by Cho (2011). The measured heave RAO and spectrum reasonably followed the trends of the predicted values. A significant motion reduction at resonant frequency was pronounced and the heaving-motion energy calculated by the integration of the area under the heave motion spectrum was reduced by more than 75% by the damping plate. However, additional energy dissipation by eddies of strong vorticity and flow separation inside a porous damping plate was not found in the present experiments.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.4
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• pp.397-402
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• 2013

In this study, numerical hull form development of a platform supply vessel, a full scale with the overall length of 26.75m, was performed to predict a bare-hull resistance and a large scale of model tests with a 1/10 scaled model were conducted to verify the success of numerical results. Numerical analysis on heave and pitch motion as a function of encounter frequency and ship's speed for the prediction of seakeeping characteristics are also presented. The experiment results of resistance agreed well with numerical analysis. As a result in the motion response characteristics, the heave RAO indicates high values with the range of encounter frequency 1.8~2.0. The Pitch RAO indicates high motion response characteristics at Beaufort scale No. 3 and 4 in rough seas.

• Journal of IKEEE
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• v.24 no.3
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• pp.735-742
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• 2020

The pick & place module is used as a core module in the process equipment for producing and inspecting semiconductor components. The conventional pick & place module has the disadvantage that the precision and durability of the system are reduced and the size and weight of the module are increased by using a conversion device that converts rotary motion into linear motion. In this study, we proposed a pick & place module that implements up-and-down linear motion without a conversion device by improving such disadvantage and employs a linear motor with no limit on average thrust and travel distance. Design parameter values, that can reduce cogging force while maintaining average thrust by selecting parameters for designing a core type linear motor with a large thrust to volume ratio and analyzing the effect of cogging force according to design parameter changes through magnetic analysis, was selected. Average thrust and cogging force were measured for the pick & place module composed of the manufactured linear motor and compared with the design values.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.509-517
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• 2009

The purpose of this study was to investigate the effective posture for air pistol shooting. Participants were 3 male athletes of shooting with at least five years of experience and another group of 3 males athletes with less than three years of experience. For the purpose, the shooting motion was analysed using three dimensional image technology. Data from each event for the two groups, competent and less competent ones, were compared to see the differences from the kinematical point of view. Time of period in competent group was longer than less competent group during the shooting posture. Displacement of center of mass and pistol about medial/lateral and antero/posterior in competent group was little than less competent group from aim to shooting. And these result were effect to the velocity. Distance and time in competent group within coaching machine were smaller than less competent group. To the result, it was appear that precision of aim in competent group was higher than less competent group.