• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.195-198
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• 2006

Zinc phosphate coating is required in nearly all steel cold forging operations. However, the chemical byproducts of this lubricant system are difficult to dispose of and have a negative environmental impact. In order to replace zinc phosphate based lubricants partially or completely, candidate lubricant has been developed in this study. The performance evaluation of these lubricants was conducted using the double cup extrusion test and spike forging test. With the use of the commercial FEM code DEFORM, friction factor calibration curves, i.e. cup height ratio vs. punch stroke and spike height vs. punch stroke, were established for different friction factor values. By matching the cup height ratio and the punch stroke and spike height vs. punch stroke from experiment to that obtained from FE simulations, the friction factor of the lubricants was determined. Three water-soluble lubricants; namely, Mec Homat, Royalcoat, and the developed lubricant were found to perform comparable to or better than zinc phosphate.

• 한국화재소방학회논문지
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• 제26권2호
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• pp.84-89
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• 2012

노말노난올의 안전한 취급을 위해, 폭발한계는 문헌을 통해 고찰하였고, 인화점과 발화지연시간에 의한 발화온도를 측정하였다. 그 결과, 노말노난올의 폭발하한계는 0.80 Vol.%, 상한계는 6.1 Vol.%를 추천하였고, 하부인화점은 밀폐계에서 $94{\sim}97^{\circ}C$와 개방식에서 $103{\sim}104^{\circ}C$로 측정되었다. ASTM E659-78 장치를 사용하여 자연발화온도와 발화지연시간을 측정하였고, 노말노난올의 최소자연발화온도는 $270^{\circ}C$로 측정되었다.

• Nuclear Engineering and Technology
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• 제52권12호
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• pp.2969-2974
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• 2020

Looking at the recent studies, nuclear energy and carbon dioxide (CO₂) emissions nexus shows inconclusive result. To further explain nuclear energy-pollution nexuses this study is an attempt to analyze the impact of nuclear energy on pollution reduction for BRICS countries covering data for the period from 1993 to 2017. This study conducts advanced panel techniques such as Continuously-Updated Fully-Modified (CUP-FM) and Continuously-Updated Bias-Corrected (CUP-BC) for long run estimation. Our results support the notion that nuclear energy reduce CO₂ emissions. Also, renewable energy corrects environmental pollution in BRICS countries. The magnitude of the coefficient of nuclear energy is less as compared to renewable energy, implying that nuclear is less effective in reducing environmental pollution. The findings offer significant policy understandings and suggestions not only for BRICS economies but for developing countries as well in designing suitable nuclear energy-growth-carbon policies.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2021년도 추계학술발표대회
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• pp.819-822
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• 2021

AI World Cup 환경은 다수 가상 에이전트들이 팀을 이뤄서 서로 상호작용하며 대전이 가능한 가상 축구 환경이다. 본 논문에서는 AI World Cup 환경에서 멀티 에이전트기반 학습/추론 기술을 사용하여 다양한 전략과 전술을 구사하는 가상 축구 에이전트 구현과 시뮬레이션 결과를 소개한다. 먼저, 역할을 바탕으로 협동하여 상대방과 대전할 수 있는 논리 기반 추론형 멀티 에이전트 기술이 적용된 Dynamic planning 축구 에이전트 9 세트를 구현하였다. 이후, 강화학습 에이전트 기반, 단일 에이전트를 조합한 Independent Q-Learning 방식의 학습형 축구 에이전트를 구현한 후, 이를 멀티 에이전트 강화학습으로 확장하여 역할 기반 전략 학습이 가능한 가상 축구 에이전트를 구현하고 시뮬레이션 하였다. 구현된 가상 축구 에이전트들 간 대전을 통해 승률을 확인하고, 전략의 우수성을 분석하였다. 시뮬레이션 예제는 다음에서 확인할 수 있다 (https://github.com/I-hate-Soccer/Simulation).

• Journal of applied mathematics & informatics
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• 제20권1_2호
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• pp.61-74
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• 2006

Let G be a simple graph and let G denote its complement. We say that $\bar{G}$ is integral if its spectrum consists of integral values. In this work we establish a characterization of integral graphs which belong to the class $\bar{{\alpha}K_{a,a}\cup{\beta}K_{b,b}}$, where mG denotes the m-fold union of the graph G.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 춘계학술대회논문집
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• pp.121-124
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• 1997

In the present study, a general tool surface contac search ad check algorithm is proposed. A general tool surface is described by triangular FE mesh. To check a proposed algorithm, clover cup and L-shape cup deep drawing processes are calculated. The elastic-plastic FEM using SEAM (Shear Energy Augmented Membrane) element is adapted for numerical stability.

• 한국생활과학회지
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• 제24권6호
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• pp.847-857
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• 2015

The ratio of small-breasted women occupies over 20% among Korean women in their twenties. However, the commercial brassieres for the small-breasted women were not fitted well to their breast shapes. In this research, the various commercial mold brasseries for small-breasted women were evaluated through the wearing test and the analysis of 3D images which were scanned from their torsos wearing the brassieres. In addition, professional panels performed the appearance evaluation based on the 2D front and side images captured from 3D images taken by 3D measurement systems. As the results, we found that small-breasted women preferred a 3/4 cup brassiere, of which volume is concentrated in the lower cup. The most preferred brassiere in wearing state shows that the characteristic angle between the chest and the upper cup is about 167 degrees, which is smaller than those of another brassieres, and that the ratio of the radius of curvature of the nipple part to that of the lower cup was about 0.78. These results provide important implications regarding the design of mold brassieres for small-breasted women in spite of the fact that these results represent the selected set of commercial brassieres. Therefore, further studies are highly demanded for the most suitable design information of mold cup for small-breasted women.

• 한국인터넷방송통신학회논문지
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• 제23권2호
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• pp.21-27
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• 2023

본 논문은 골프에서 퍼팅 조준을 도와주는 앱의 개발에 관한 연구이다. 제안된 앱은 그린에서의 홀 컵의 위치와 크기를 측정하여 조준 시 홀 컵과 조준 지점과의 거리를 알려준다. 이를 위하여 인공지능의 객체 인지 기술을 적용하여 개발하였다. 스마트 폰의 카메라로부터 들어오는 이미지에 대하여 객체 인지 기술을 사용하여 실시간으로 홀 컵의 위치와 크기를 측정한다. 그 결과를 이용하여 카메라의 이미지 위에서 조준 지점과 홀 컵과의 거리를 표시함으로써 조준을 도와주는 것이다. 제안된 앱은 아이폰의 iOS에서 개발하였다. 개발된 앱의 성능 측정 결과 실시간으로 충분히 홀 컵을 인지하여 도움 정보를 출력할 수 있었으며, 표시된 거리도 조준에 도움이 될 정도로 정확하였다.

• 한국안전학회지
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• 제33권6호
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• pp.28-36
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• 2018

There was a difference in recognition of respirators according to the educational performance environment. they were showed higher recognition of respirators of group by internal and external mix trainer, less than 6 months, over 1hour, more than 5 times, variety of education. To identify the relationship between types of job classification(typical and atypical)and the levels of recognition of respirators, a total of 153 workers in a business workplace. mainly, typical workers showed higher recognition of respirators than atypical workers. Training of correct wearing showed high demands both typical and atypical workers. Descriptive statistics(SAS ver 9.2)was performed. the results of recognition of respirators were analyzed the mean and standard deviation by t-test, and anova, fit factor is used geometric means(geometric standard deviation), paired t-test, Wilcoxon analysis(P=0.05). Particulate filtering facepiece respirators (PFFR) is one of the most widely used items of personal protective equipments, and a tight fit of the respirators on the wearers is critical for the protection effectiveness. In order to effectively protect the workers through the respirators, it is important to find and evaluate the ways that can be readily applicable at the workplace to improve the fit of the respirators. This study was designed to evaluate effects of mask style (cup or foldable type) and donning training on fit factors (FF) of the respirators, since these are available at various workplace, especially at small business workplace. A total of 40 study subjects, comprised of employment type workers in metalworking industries, were enrolled in this study. The FF were quantitatively measured before and after training related to the proper donning and use of cup or foldable-type respirators. The pass/fail criterion of FF was set at 100. After the donning training for the cup-type mask, fit test were increased by 769%. but foldable-type mask was also increased after the donning training, the GM of FF for the foldable-type mask and it's increase rate were smaller as compared to the cup-type mask. Furthermore, the differences of the increase rates of the GM of FF in employment type of the subjects were not significantly for the foldable-type mask. These results imply that the raining on the donning and use of PFFR can enhance the protection effectiveness of cup or foldable-type mask, and that the training effects for the foldable-type mask is less significant than that for the cup-type mask. Therefore, it is recommended that the donning training and fit tests should be conducted before the use of the PFFR, and listening to workers opinion regularly.

• Ecology and Resilient Infrastructure
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• 제3권1호
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• pp.35-45
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• 2016

섬강 시험유역의 지형학적 특성 매개변수와 SWAT-CUP의 SUFI-2 알고리즘을 이용한 SWAT 모형 매개변수와의 상관관계와 이들의 관계식을 개발하였다. 개발한 상관 관계식을 이용하여 속사천 유역의 SWAT 모형의 매개변수를 추정하였다. 아울러, 속사천 유역의 2000 - 2007년의 강우-유출 자료를 대상으로 SWAT-CUP의 SUFI-2 알고리즘을 이용하여 SWAT 모형의 매개변수를 추정하였다. 개발한 식에 의해 산정한 각 매개변수의 적용성을 검토하기 위해 2000 - 2007년의 속사천 시험유역 자료를 이용하여 SWAT 모형의 유출모의를 실시하였다. 실측자료와 지형학적 특성 매개변수의 상관관계 분석으로 산정된 매개변수를 이용하여 속사천에 적용한 유출 모의결과와의 RMSE (root mean square error)는 $1.09m^3/s$이고, SWAT-CUP의 SUFI-2 최적 매개변수를 적용한 유출 모의결과와의 RMSE는 $0.93m^3/s$으로 나타났다. 따라서 지형학적 특성 매개변수를 이용한 SWAT 모형의 매개변수 추정이 적용성이 있다고 판단된다.