• Title/Summary/Keyword: theoretical test

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현장 타설용 고분자 감쇠재의 탄성 계수를 측정하기 위한 실험 기법 (Dynamic Test method to Determine Modulus of Elasticity of Sound Insulating Coat)

  • 이맘 딘베루 몰라;이종구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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    • pp.92-93
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    • 2015
  • The main purpose of this paper is to present the dynamic test method developed for measuring the elastic modulus of sound insulating coat. The test setup was devised based on the theoretical natural frequency of a simply-supported beam subject to free transverse vibration. A stainless steel beam was tested and the result showed a good compliance with the standard value listed in literatures. The result indicates that the test set up can serve as a quick, economical and suitable scheme to test non self-supporting materials.

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피에조콘 소산시험을 이용한 평형간극수압과 강성지수의 역해석 (Identification of ambient pore pressure and rigidity index from piezocone dissipation test)

  • 김영상
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 봄 학술발표회 논문집
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    • pp.49-54
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    • 2002
  • This paper describes a systematic way of simultaneously identifying the ambient pore pressure and the rigidity index (=G/s$\_$u/) of soil by applying an optimization technique to the piezocone dissipation test result. An ambient pore pressure and optimal rigidity index were determined by minimizing the differences between theoretical excess pore pressures developed by Randolph & Wroth(1979) and measured excess pore pressures from piezocone using optimization technique. The effectiveness of the proposed back-analysis method was examined against the well-documented performance of piezocone dissipation tests (Tanaka & Sakagami, 1989), from the viewpoints of proper determination of selected target parameters and saving of test duration. It is shown that the proposed back-analysis method can evaluate properly the ambient pore pressure and the rigidity index by using only the early phase of the dissipation test data. Also, it is shown that with the optimized rigidity index and ambient pore pressure the proposed back-analysis method permits the horizontal coefficient of consolidation to be identified rationally.

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여과시스템 모델과 자동차 연료필터의 비교성능시험 연구 (A Study on Filtration System Model and Comparative Performance Tests of Automotive)

  • 이재천
    • 한국정밀공학회지
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    • 제20권3호
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    • pp.194-201
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    • 2003
  • This study presents the comparative filtration performance evaluation of automotive fuel filters based on the theory of Beta ratio. For the experiments, the fuel component's test stand incorporating the multi-pass filtration test circuit was developed. A mathematical description of filtration process in general was derived. And the theoretical basis of multi-pass test and the test procedure were described in detail. Experimental results revealed that domestic fuel filter tested could not maintain consistent Beta ratio, that is filtration efficiency, although it had the holding capacity of contaminants close to the specification at maximum pressure drop across the filter assembly. The results of experiments and simulations also showed that filtration system model could be refined including desorption ratio to estimate the variable Beta ratio in service life.

지게차용 엔진식 드라이브 액슬 수명평가를 위한 가속수명시험 선정 연구 (Accelerated Life Test Selection Study for Life Evaluation of Engine Type Drive Axle for Forklift)

  • 김준영;유영준;이철희
    • 드라이브 ㆍ 컨트롤
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    • 제20권3호
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    • pp.9-14
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    • 2023
  • In this paper, the selection of a reliable accelerated life test code for a 2-ton forklift was accomplished by choosing the driving resistance coefficient failure-free test time based on a 10,000-hour B10 life. The overall life and average equivalent load of the vehicle were then calculated based on actual driving test conditions using the selected driving resistance coefficient. The gear train's accelerated life test code was selected by adjusting the equivalent load to a torque and rotation speed that did not exceed 125%(about 75HP) of the vehicle rated power. The safety of the test standards was validated by conducting an actual accelerated life test utilizing the proposed test method in this study and comparing the test result with the corresponding theoretical value. It is anticipated that the reliability of the accelerated life test in this paper will be enhanced, by incorporating actual driving performance data collected directly from the forklift and adjusting the conditions used in developing the accelerated life test code.

반잠수식 시추선에 작용하는 장주기 표류력에 관한 연구 (A Study on the Slowly Varying Wave Drift Force Acting on a Semi-Submersible Platform in Waves)

  • 홍사영;이판묵;홍도천
    • 대한조선학회지
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    • 제26권2호
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    • pp.49-63
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    • 1989
  • 파랑표류력은 크기에 있어서는 2차항(2nd-order)의 힘으로, 파도의 주기로 나타나는 1차항(1st-order)의 파랑강제력에 비해 미미하나, 부유체 자체의 복원력이 없는 수평방향으로 작용하므로 부유체에 대변위 표류운동을 유발한다. 특히 장주기 표류력은 계류시스템에 장주기 대변위 공진응답을 야기시킬 수 있으므로 계류시스템의 설계 및 운용에 고려되어야 할 중요한 요소이다. 본 연구에서는 이론적 연구로서 개량된 Green 적분방정식을 이용하여 3차원 특이점을 분포하는 방법으로 near field법을 택하여 장주기 파랑표류력을 계산하였으며 계산결과는 Pinkster 및 Standing의 결과와 비교하였다. 비선형파의 산란효과 고려는 Pinkster의 근사방법을 따랐다. 실험적 연구로서 반잠수식 시추선의 1/60 모형에 대해 규칙파 및 불규칙파중 표류력계측시험을 수행하였으며 실험결과는 계산치와 비교되었다. 끝으로 계측시험에 있어 계류스프링의 영향 및 장주기 표류력 계측에 있어서 실험상 문제점을 논하였다.

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사질토 지반에서 Shell 기초 거동에 대한 연구 (A Study on Shell Foundation Behaviour in Cohesionless Soil)

  • 김상환;이충환;최충식
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.1144-1154
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    • 2008
  • In this paper, the behaviour of shell foundation was studied. In order to perform this study, three studies such as theoretical, numerical and experimental programs were performed. In the theoretical program, the general shallow foundation theories and failure mechanism developed by Terzaghi, Mayerhof and others were reviewed and compared. Based on the previous shallow foundation behaviour, the shell foundation theory was developed using the upper boundary theorem. In the numerical study, the 2 and 3 dimensional FEM simulations were carried out using an uncoupled-analysis approach. From the analysis results, the adequate depth of shell foundation was evaluated. It was also evaluated the bearing capacity according to the shell angle ($120^{\circ}$, $90^{\circ}$, $60^{\circ}$). In the experimental study, the laboratory model tests were carried out for five cases of different foundation shapes including the rectangular and circular foundation in order to verify the theoretical and nemerical study. According to the results of this study, the bearing capacity of shell foundation was theoretically about 15% larger than that of general foundation. However, in the model test, the bearing capacity of shell foundation was about 25 to 30% larger than that of general foundation. In the case of shell angle, the maximum bearing capacity of shell foundation shows when the shell angle of foundation was $60^{\circ}$. In addition, Even if the shell foundation has the various advantages compared with the general foundations as described above, the practical verifications in full scale size will be necessary to use in the field and will be helpful in the technical development of other special foundations.

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3D 콘텐츠 깊이 측정기를 이용한 오브젝트의 돌출거리 측정 (Measuring Perceived Depth For The Object Using 3D Content Depth Measuring Instrument)

  • 한동희;강행봉;김석호
    • 한국멀티미디어학회논문지
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    • 제16권9호
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    • pp.1109-1118
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    • 2013
  • 최근 들어 S3D 콘텐츠가 광범위하게 대중화되고 있다. 하지만, 일부의 사람들은 3D 정보를 정확하게 인지하지 못하고 있다. 기존의 입체시 검사 도구는 입체의 인지 여부를 판단하는 테스트만 수행하고, 피험자가 인지하는 정확한 깊이 정보를 측정할 수 없다. 따라서 정확하게 측정할 수 있는 검사도구가 필요하다. 본 논문에서는 3D 콘텐츠 깊이 측정기 및 측정기에 적합한 3D 콘텐츠를 제작하고, 3D 오브젝트의 양안시차(disparity)에 대한 피험자가 인지하는 3D 오브젝트의 돌출거리를 측정하고, 이론값(예측값)과 측정값을 비교 및 관계를 분석하였다. 그 결과 측정값은 이론값보다 약간 크게 나타났으며, 돌출거리가 클수록 편차가 크게 나타났다.

헤어패션감각(感覺)에 따른 헤어컬러에 관(關)한 연구(硏究) - 수도권(首都圈) 20대(代) 여성(女性)을 중심(中心)으로 - (A Study on the Hair Colour Accompanied with Hair Fashion Feeling - Focussed on the Capital Area Women in Their Twenties -)

  • 안현경;조규화
    • 패션비즈니스
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    • 제10권2호
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    • pp.99-116
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    • 2006
  • This study was aimed at giving help to the people intending to change their hair fashion feeling for changing their own hair colour design and also providing the guide line to the cosmetic circles for developing new hair colour design and promoting sales by statistically analyzing hair colours and the other factors(demographic characteristics, hair styling, total fashion feeling, hair style) of capital area women in their twenties based on the theoretical study on tatal fasion feeling & hair fashion feeling, and hair trend. The researching methods were composed of prior theoretical research, statistical analysis. The prior theoretical research was accomplished by analysis of literatures, magazines and internet sites about total & hair fashion feelings and hair trend. The statistical analysis used a questionnaire composed of 33 questions in 5 categories. The survey of the questionnaire had been conducted from June 15 to June 28 in 2005 on the 600 women in the capital area, investigated by a group of experts on cosmetics or clothing from academic or business society. The analysis of materials from the survey was done by SPSS program(ver. 12.0) using frequency analysis, $x^2$-test and cross tabulation analysis specified on high significant values. Based on the above results of $x^2$-test and cross tabulation analysis, categorized the characteristics of the hair fashion feeling groups, especially hair colours in the order of percentage. This study would be very helpful to the people trying to change their own hair fashion feeling and be useful to the cosmetic circles for developing new hair colour design and promoting sales by comprehending hair colour market and also be valuable to develop the analysis methodology of hair colour and hair fashion trend.

수중 주파수영역표면파괴기법의 역해석 과정에서 적용되는 파동해석기법 (Theoretical Modeling of Surface Wave Propagation for SASW Testing Method)

  • 이병식
    • 지구물리
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    • 제3권4호
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    • pp.251-260
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    • 2000
  • 수중 SASW 실험에서 얻은 표면파의 실험분산곡선으로부터 지반의 강성을 추정하기 위한 역해석 과정에서 적용할 수 있는 파동해석기법인 로드해석법(2차원 해석법)과 변위해석법(3차원 해석법)의 적용성을 평가하였다. 그 결과 지반의 강성이 깊이에 따라 점진적으로 증가하고 지반 강성이 비교적 낮아 그 압축파 속도가 물의 압축파 속도보다 느린 경우에 대해서는 고유치 해석법을 적용할 수 있었다. 그러나 지반의 강성이 크거나 깊이에 따른 지반강설의 변화가 역전되는 경우에는 고차모트의 영향이나 고유치가 복소수가 되는 등의 문제가 발생하게 되므로 고유치 해석법으로 적절한 이론분산곡선을 얻을 수 없는 경우가 많고, 이 경우에는 변위해석법을 적용하여야 한다는 결론을 얻었다. 한편 수중 SASW 현장실험으로부터 얻은 결과를 제안된 변위해석법을 이용하여 분석한 결과 지반의 강성주상을 적절하게 추정한 수 있어 수중 SASW 실험의 현장 적용성을 확인할 수 있었다.

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The Influence of Trade and Foreign Direct Investment on Green Total Factor Productivity: Evidence from China and Korea

  • Li, Kan-Yong;Gong, Wen-Chao;Choi, Beak-Ryul
    • Journal of Korea Trade
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    • 제25권2호
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    • pp.95-110
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    • 2021
  • Purpose - This paper intends to conduct theoretical analysis and empirical test on the action mechanism of South Korea-China trade and South Korea's FDI to China on green total factor productivity, so as to provide a new perspective and ideas for the improvement of China's green total factor productivity and promote the high-quality development of China's economy Design/methodology - This paper uses the data of 30 provinces, autonomous regions and municipalities in China from 2004 to 2017 as the research sample, adopts the GML index method of SBM Directional Distance Function to measure GTFP, and analyzes the influence of South Korea-China trade and FDI from South Korea on China's GTFP. Findings - Trade is conducive to promoting technological progress, which has a significant promotion effect on China's green total factor productivity. While FDI has a significant inhibitory effect on China's green total factor productivity, which verifies the "pollution haven" hypothesis. In addition, such influence has certain regional overall heterogeneity. Trade has a more significant promoting effect on GTFP in eastern coastal areas, while FDI has a more significant inhibitory effect on GTFP in central and western inland areas. The interaction between trade and FDI is conducive to the improvement of green total factor productivity, indicating that the benign mechanism of trade and FDI has been formed. Urbanization, industrial structure, human resource level and investment in science and technology are all conducive to the improvement of GTFP. Originality/value - Through theoretical analysis and empirical test on the action mechanism of South Korea-China trade and South Korea's FDI on green total factor productivity, this paper provides a solid theoretical foundation for the further development of China-South Korea economic and trade cooperation in the future.