• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1174-1177
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• 2003

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation was studied with numerical method by ABAQUS S/W. Polymer (PMMA) and brittle materials (Si, Pyrex glass) were used as specimens, and forming conditions to reduce the elastic recover and pile-up was proposed. The indenter was modeled a 3D rigid surface. Minimum mesh sizes of specimens are 1-10nm. Comparison between the experimental data and numerical result demonstrated that the finite element approach is capable of reproducing the loading-unloading behavior of a nanoindentation test. The result of the investigation will be applied to the fabrication of the hyper-fine pattern.

• 한국의류산업학회지
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• 제9권4호
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• pp.445-449
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• 2007

The results of warmth retaining, heat transfer and compressive elastic recovery of the five kinds of bedspread fabrics, which were produced from packing weft of 2700 denier and 3600 denier batt yarn treated with raw material of Polyester $150^D$/48 DTY, are as follows: 1) 3600 denier packing weft showed lover count in compressive elastic recovery than 2700d packing weft, so it took longer time to recover. 2) When packing weft of the same count is used, a sample of packing weft with higher density showed lower recovery. 3) It took 2700d packing weft 30min to get approximately 98% recovery in temperature $30^{\circ}C$. But, 3600d packing weft stayed under 98% recovery in the same temperature. Considering only the result of compressive elastic recovery, we should use 2700d packing weft. 4) The higher the density of packing weft is, the higher warmth retaining becomes. Although sharp increase appeared until 5min, equilibrium was kept without any increase after that time. 5) When 2700d packing weft was used, the maximum warmth retaining was approximately 60% and 64% in the conditions of density 12(thread/in) and 22(thread/in) respectively.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.116-119
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• 2003

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation was studied with numerical method by ABAQUS S/W. Brittle materials (Si, Pyrex glass) were used as specimens, and forming conditions to reduce the elastic restoration and pile-up was proposed. The indenter was modeled a rigid surface. Minimum mesh sizes of specimens are 1-10nm Comparison between the experimental data and numerical result demonstrated that the finite element approach is capable of reproducing the loading-unloading behavior of a nanoindentation test. The result of the investigation will be applied to the fabrication of the hyper-fine pattern.

• 한국철도학회논문집
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• 제14권3호
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• pp.256-261
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• 2011

최근 경부고속철도 자갈도상 구간의 일부에서 침하가 발생되고 이로 인하여 열차의 안전 및 운행속도와 승차감 저하라는 문제가 발생하였다. 따라서 이 문제를 해결하고 KTX 열차 운행을 정상화하기 위한 긴급대책이 요구된 적이 있었다. 본 논문에서는 이러한 현장의 요구에 대처하기 위해 철도노반 단층영상화 기법을 도입하게 되었다. 철도노반 단층영상화 기법은 철도노반의 지반강성을 단층영상의 형태로 가시화함으로써, 잠재적으로 과도한 침하를 유발할 수 있는 철도노반의 연약부위를 찾는데 있어서 현장기술자의 신속한 판단을 가능하게 하는 기법이다. 제안된 기법의 타당성과 적용성을 평가하기 위하여 실제 자갈도상 철도노반과 신설 철도노반 등 두 현장에 적용하여 보았고, SASW, PBT, DCP, FWD 시험결과와 비교하였다.

• Elastomers and Composites
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• 제35권1호
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• pp.4-11
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• 2000

어큐뮬레이터에 사용되는 얇은 막 형태의 고무다이아프램은 외부의 맥동 및 충격압력을 흡수하고 유체의 수송과 압력을 전달하는 역할을 수행하며, 압력 변화에 따른 변형 거동은 어큐뮬레이터의 특성을 결정하는 중요한 설계 변수이다. 고무다이아프램은 고무 자체의 비선형성에 의한 비선형거동과 작은 압력 변화에도 큰 변형을 일으키는 대변형 거동을 나타내며, 임의 압력 이상에서는 고무다이아프램이 변형된 후 용기에 접촉되는 현상이 나타난다. 본 연구에서는 비선형 대변형 해석과 접촉 해석 둥이 용이한 구조해석 소프트웨어인 MARC를 이용하여 두 가지 형상에 대한 고무다이아프램의 거동을 해석하여, 고무 물성 변화와 압력 변화에 따른 변형 거동을 예측하고 파손 취약 부위로 예상되는 다이아프램의 고정 부위에서의 응력을 완화하기 위한 설계 개선 방안을 제시하였다.

• Steel and Composite Structures
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• 제9권3호
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• pp.191-208
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• 2009

Observations from experiments and real fire indicate that restrained steel beams have better fire-resistant capability than isolated beams. Due to the effects of restraints, a steel beam in fire condition can undergo very large deflections and the run away damage may be avoided. However disgusting damages may occur in the beam-to-column connections, which is considered to be mainly caused by the enormous axial tensile forces in steel beams resulted from temperature decreasing after fire dies out. Over the past ten years, the behaviour of restrained steel beams subjected to fire during heating has been experimentally and theoretically investigated in detail, and some simplified analytical approaches have been proposed. While the performance of restrained steel beams during cooling has not been so deeply studied. For the safety evaluation and repair of steel structures against fire, more detailed investigation on the behaviour of restrained steel beams subjected to fire during cooling is necessary. When the temperature decreases, the elastic modulus and yield strength of steel recover, and the contraction force in restrained steel beams will be produced. In this paper, an incremental method is proposed for analyzing the behaviour of restrained steel beams subjected to cooling. In each temperature decrement, the development of deformation and internal forces of a restrained beam is divided into four steps, in order to consider the effect of the recovery of the elastic modulus and strength of steel and the contraction force generated by temperature decrease in the beam respectively. At last, the proposed approach is validated by FE method.

• Earthquakes and Structures
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• 제17권4호
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• pp.365-372
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• 2019

Post-earthquake crisis management is a key capability for a country to be able to recover after a major seismic event. Instrumental seismic data transmitted and processed in a very short time can contribute to better management of the emergency and can give insights on the earthquake's impact on a specific area. Romania is a country with a high seismic hazard, mostly due to the Vrancea intermediate-depth earthquakes. The elastic acceleration response spectrum of a seismic motion provides important information on the level of maximum acceleration the buildings were subjected to. Based on new data analysis and knowledge advancements, the acceleration elastic response spectrum for horizontal ground components recommended by the Romanian seismic codes has been evolving over the last six decades. This study aims to propose a framework for post-earthquake warning based on code spectrum exceedances. A comprehensive background analysis was undertaken using strong motion data from previous earthquakes corroborated with observational damage, to prove the method's applicability. Moreover, a case-study for two densely populated Romanian cities (Focsani and Bucharest) is presented, using data from a $5.5M_W$ earthquake (October 28, 2018) and considering the evolution of the three generations of code-based spectral levels for the two cities. Data recorded in free-field and in buildings were analyzed and has confirmed that no structural damage occurred within the two cities. For future strong seismic events, this tool can provide useful information on the effect of the earthquake on structures in the most exposed areas.

• 한국한의학연구원논문집
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• 제1권1호
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• pp.321-333
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• 1995

The author performed in 10 cases under the age of 13 years who were visited to hospital from July 1994 to July 1995. I have assessed information such as type of deviation, detected time of strabismus, past history, family history. The most of patient were esotropia. I have experienced good improvement to recover strabismus by the Oriental Medicine. The acupuncture points of B2, TE23, S1, G14, E36 were used. Herbal medicine was treated GAMIBOJOONGYKGI-TANG. It was supposed to encourage digestive system and to continue elastic capacity. From the results of this study, it is effective to change of correct position at the deviatinal eyeball and to treat amplyopia with strabismus. It was reported possble to treat strabismus without operation and glasses.

• 한국자동차공학회논문집
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• 제20권4호
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• pp.68-75
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• 2012

This paper presents a study on the driveline output torque estimation using a discrete Kalman filter. The in-situ output shaft torque is first measured by a non-contacting magneto-elastic torque transducer. The linear state-space system equations are first derived and the discrete Kalman filter is designed based on the Kalman filter theory to recover the driveline output torque contaminated by random noises. In addition to using torque measurement, the estimation of the output torque using two angular velocities: the output and wheel, is also conducted. The experimental results show that the discrete Kalman filter can be effective for not only removing the random noise in output torque but also estimating the output torque without torque measurement.

• 한방안이비인후피부과학회지
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• 제8권1호
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• pp.133-142
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• 1995

The author performed in 10 cases under the age of 13 years who were visited to hospital from July 1994 to July 1995. I have assessed information such as type of deviation, detected time of strabismus, past history, family history. The most of patient were esotropia. I have experienced good improvement to recover strabismus by the Oriental Medicine. The acupuncture points of B2, TE23. S1, G14, E36 were mainly used. Herbal medicine was treated GAMIBOJOONGYKGI-TANG. It was supposed to encourage digestive system and to continue elastic capacity. From the results of this study, it is effective to change of correct position at the deviational eyeball and to treat amp1yopia with strabismus. It was reported possble to treat strabismus without operation and glasses.