• 동력기계공학회지
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• 제20권3호
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• pp.57-63
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• 2016

This paper presents the experimental result and theoretical analysis result to investigate the correlation between the operating force, angle and locking torque for vehicle hood frame. Also, we derived the experimental equation that using the results for experiment and theory. The hood frame is switching-devices used for opening and closing the vehicle hood. It needs the correlation data between locking torques of each joint, operating force and angle of hood frame. The correlation data for torque and reaction force of hood frame obtained through experiment and theory analysis. Finally, the experimental equation of the locking torque prediction for the hood frame is derived.

• Structural Engineering and Mechanics
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• 제64권3호
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• pp.287-292
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• 2017

In the present research, an available flexural stiffness degradation model was modified and a new comprehensive model called "X-NFSD" was developed. The X-NFSD model is capable of predicting the flexural stiffness degradation of composite specimen at different states of stresses and at room temperature. The model was verified by means of different experimental data for chopped strand mat/epoxy composites under displacement controlled bending loading condition at different displacements and states of stresses. The obtained results provided by the present model are impressively in very good agreement with the experimental data and the mean value of error of 5.4% was achieved.

• 대한조선학회논문집
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• 제40권3호
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• pp.9-15
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• 2003

An experimental study has been carried out as a basic research for development of the friction drag reduction technology for ships by polymer injection. Experimental apparatus and procedures have been devised and prepared to measure the changes of the wall friction with injection of a polymer solution and basic experimental data on the friction drag reduction are obtained for a turbulent fiat-plate boundary layer and fully-developed channel flows. Variations of the friction drag reduction with some important parameters of polymer injection, such as the concentration of polymer solution, its injection flow rate and the measuring position downstream from the injection slot, are also investigated. Important experimental data and results obtained in the present study are presented. The amount of friction drag reduction up to 50% is observed.

• 수산해양교육연구
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• 제10권1호
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• pp.63-68
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• 1998

The microbubble splits injection system are improved for the enhancement efficiency of viscous frictional drag reduction. It was confirmed that the experimental results is effective more than Mercle's[7] using the present system in the comparisons. And the new experimental equation is derived to get viscous frictional drag reduction useful for the present experimental data. The new experimental equation approaches Mercle's[7] experimental data wel.

• 한국해양공학회지
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• 제33권4호
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• pp.358-363
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• 2019

The acoustic power is used as a primary index characterizing underwater sound sources and could be defined by its source level. The source level has been assessed using various experimental techniques such as the reverberation time method and reverberant tank plot method. While the reverberation time method requires reverberation time data extracted in a preliminary experiment in a reverberant water tank, the reverberant tank plot method only needs acoustic pressure data directly obtained at the reverberation water tank. In this research, these experimental techniques were studied in comparative experiments to estimate the source levels of underwater sources in a reverberant water tank. This paper summarizes the basic theories and procedures of these experimental techniques and presents the experimental results for an underwater source in a long cuboid water tank using each technique, along with a discussion.

• Journal of Mechanical Science and Technology
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• 제20권9호
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• pp.1399-1409
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• 2006

An improved friction model was proposed with consideration of the effect of the sliding speed, the contact pressure and the temperature, and it was implemented into a user subroutine of a commercial FEM code, ABAQUS/Explicit. Then, a smooth tire was simulated for free rolling, driving, braking and cornering situations using the improved friction model and the Coulomb friction model, and the effect of the friction models on the slip, the frictional energy distribution and the cornering force and moment was analyzed. For the free rolling, the driving and the braking situations, the improved friction model and the Coulomb friction model resulted in similar profiles of the slip and the frictional energy distributions although the magnitudes were different. The slips obtained from the simulations were in a good correlation with experimental data. For the cornering situation, the Coulomb friction model with the coefficient of friction of 1 or 2 resulted in lower or higher cornering forces and moments than experimental data. In addition, in contrast to experimental data it did not result in a maximum cornering force and a decrease of the cornering moment for the increase of the speed. However, the improved friction model resulted in similar cornering forces and moments to experimental data, and it resulted in a maximum cornering force and a decrease of the cornering moment for the increase of the speed, showing a good correlation with experimental data.

• 한국지구과학회지
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• 제36권4호
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• pp.367-389
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• 2015

본 연구에서는 Ocean Data View (ODV)를 이용하여 한반도 주변 해역의 수온 염분 분포도를 작성하는 실험 프로그램을 개발하였다. 정선 해양 관측 자료는 본 연구를 위해 새롭게 개발된 별도의 프로그램을 이용하여 ODV 호환형식으로 변환된 후 분석되었다. 새로운 실험 프로그램을 65명의 예비 교사들에게 적용하였을 때, 기존 프로그램을 사용한 같은 집단에 비해 과제 수행 완성도가 매우 향상되었다. 새로운 프로그램에 대한 실험 참가자들의 만족도를 살펴보기 위해 설문지 분석을 실시하였다. 분석 결과 정확하고 빠른 등치선 작성 분야에서 가장 높은 만족도를 나타내었으며, 새로운 실험 프로그램의 이해 및 적용에 관한 긍정적인 반응을 확인하였다.

• 한국화재소방학회논문지
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• 제33권4호
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• pp.50-58
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• 2019

구획실 내 가연물들의 화재거동에 대한 B-RISK의 예측성능을 Fire dynamics simulator (FDS)와 연계하여 검토하였다. 먼저 열발생률(Heat release rate, HRR)에 대한 B-RISK의 예측성능을 검토하기 위해 가연물 한 세트의 실험에서 측정된 HRR 값과 디자인 화재곡선을 B-RISK의 입력조건으로 사용하여 가연물 두 세트에 대한 HRR 곡선을 계산하고 실험에서 측정된 가연물 두 세트의 HRR 값과 비교하였다. B-RISK 결과와 실험결과를 비교하여 B-RISK가 화재성장률에 대한 예측은 어렵지만 최대 HRR 값과 총 열발생량에 대해서는 충분히 예측할 수 있음을 확인하였다. 그리고 B-RISK 계산을 통해 예측된 HRR 값을 FDS의 입력조건으로 사용하여 계산된 결과와 실험결과를 비교하여 B-RISK 계산을 통해 예측된 HRR 값의 화재거동에 대해 검토하였다. 실험에서 측정된 온도 및 화학종 농도 결과와 비교하여 화재성장구간에 대해 차이가 있는 것을 확인하였지만 예측된 HRR 값에서 Percentile이 약 70%인 HRR 값을 사용하더라도 충분히 전체적인 화재거동을 예측할 수 있음을 확인하였다.

• 대한조선학회논문집
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• 제35권4호
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• pp.19-26
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• 1998

본 논문은 선박의 조종성능을 추정하기 위하여 선체에 작용되는 유체력과 선체-프로펠라-타 상호 간섭 계수들에 대해 실험 및 반경험적 방법을 사용한 유사선 개념[1,2]을 도입하였다. 유사선 개념은 새로운 선박과 가장 유사한 선박의 기 실험된 데이타를 기본으로 채택한다. 유사선 개념을 적용하기 위해 기 실험된 선박에 대한 실험데이타가 존재해야 되며, 선체력의 변화를 평가하기 위한 반경험적방법이 채택되어야 하고, 기 실험된 선박의 데이타를 수정할 방법이 반드시 존재해야 된다. 유사선 개념을 근간으로, 만재흘수 상태의 실험결과를 이용하여 경하 및 하기만재흘수 상태에서의 선박조종성능을 추정하였고, 또한 유사선으로 기 실험된 선박을 선택하여 새로운 선박의 조종성능을 추정하였다. 본 논문의 계산 방법이 초기 설계단계에서 선박의 조종성능을 정확하게 추정할 수 있음을 확인하였다.

• 복식문화연구
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• 제19권5호
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• pp.1049-1060
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• 2011

The purpose of this study was to develop a shirt pattern that enhances the functionality of golf swing motions. The pattern was made with 3D body surface shape data that changed according to dynamic golf postures. The data were collected from the golf swing motions. The 3D body surface data in golf swing postures piled up on the 3D surface data in a static posture. The results showed that the surface shape data changed more in the address, back swing, and finish postures than the other swing postures. The experimental pattern was developed with 3D surface scan data in those three golf swing motions. The pattern had raglan sleeves and the front-bodied piece was divided into two pieces with a princess line, which comes from armscye line of the address posture. The back bodice piece was divided into three pieces with a yoke line and a back princess line. The yoke line was made by back shoulder shape in the back swing posture. The level of comfort of the experimental garment and commercial golf shirts was evaluated by 38 women golfers. The experimental garment pattern was evaluated to be more comfortable in golf swing postures than commercial golf shirts.