• 콘크리트학회논문집
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• 제28권1호
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• pp.23-31
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• 2016

수축 균열의 저감 대책으로서 팽창재를 적용한 콘크리트의 모델화에 관한 연구로서 선행하여 구축한 모델을 바탕으로 팽창재에 의한 콘크리트의 수축저감 및 균열억제 효과에 대한 매크로 예측 수법을 제안하고 타당성을 검증했다. 또한, 모델의 적용을 실부재로 확장해, 실부재에 발생하는 변형을 예측하는 한편, 실부재에 발생하는 응력을 예측하여, 기존의 방법에 따른 결과와 비교 검토함으로서 본 연구에서 제안하는 모델의 타당성을 검증했다. 본 연구로부터 실시한 팽창재를 혼입한 콘크리트에 대한 이론적인 모델의 검토로부터 팽창콘크리트의 실구조물 레벨로의 검토와 함께 수축저감 및 균열억제 효과에 대한 매크로 예측수법의 제안은 향후, 팽창콘크리트의 적용 및 실용화에 있어, 실증적인 데이터를 제공할 수 있다고 생각한다.

• 응용통계연구
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• 제22권2호
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• pp.403-414
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• 2009

국내외적으로 지역통계에 관한 관심이 높아지고 있으며 이와 관련하여 소지역 추정에 관한 많은 연구가 진행되고 있다. 소지역 추정에 사용되는 추정량의 대부분은 MSE(moan squared error)를 최소화하여 얻어진다 (Rao, 2003). 최근 황희진과 신기일 (2008)은 MSPE(mean squared percentage error)를 최소화하는 추정량을 사용한 소지역 추정법을 제안하였다. 본 논문에서는 노동통계 중 지청별 일인당 평균 임금총액 추정에 황희진과 신기일 (2008)이 제안한 방법을 적용하여 보았으며 2007년 매월 노동통계 자료를 이용하여 기존의 MSE를 최소화 하여 얻어진 여러 추정량과 우수성을 비교해 보았다. 또한 노동통계를 위 한 소지역 추정의 실제 사용 가능성을 살펴보았다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
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• pp.142-147
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• 1993

In the reinforced concrete structure, as the height of building structure increases, the accurate estimation of differential column shortening is important factor in the structural design. In this study, the analysis of column shortening is applied to 36-story building structure to be built in time. As a result, it may found that, as the difference of compressive stress become larger, differential shortening effect due to creep and shrinkage are more signicant factor to structural designer.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.319-322
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• 2005

When a concrete structure is subjected to load, its response is both immediate and time dependent. Under sustained load, the deformation of a structure gradually increases with time and eventually may be many time greater than its instantanneous value. The gradual development of strain with time is caused by creep and shrinkage. On this study, to estimate of stress variations on time effects in partially prestressed concrete composite girder bridges, computer program applied Age-adjusted Effective Modulus Method(AEMM) in used.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.805-806
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• 2009

• 소성∙가공
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• 제6권6호
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• pp.489-499
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• 1997

The injection molding process is analyzed to get the information on the mold design parameters and the optimum process conditions for automotive plastic front fender. The gate position, runner size and cooling channel are determined by the estimation of the flow balance, packing time, uniform cooling and shrinkage and warpage in the injection molding analyses. The procedure can be used in the mold design in the early stage when developing plastic parts.

• 품질경영학회지
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• 제19권2호
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• pp.40-51
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• 1991

The $C_B$ statistic, a generalization of Mallows's $C_L$ statistic, is developed to determine the shrinkage parameter. Since not all cases in a data set play an equal role in forming $C_B$, a subdivision of $C_B$ into individual components for each case is developed. This subdivision is useful both as an aid in understanding $C_B$ and as a diagnostic procedure.

• 통합자연과학논문집
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• 제6권4호
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• pp.251-255
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• 2013

For the mean vector of a p-variate normal distribution ($p{\geq}4$), the optimal estimation within the class of modified James-Stein type decision rules under the quadratic loss is given when the underlying distribution is that of a variance mixture of normals and when the norm ${\parallel}{\theta}-\bar{\theta}1{\parallel}$ it known.

• Journal of Welding and Joining
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• 제28권1호
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• pp.92-99
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• 2010

For the last couple of decades many studies have been carried out to find out solutions to improve the effectiveness and productivity of the plate forming process. The practical way for the automation of the plate forming process has not been, however, developed yet. Since the characteristics of heating machines may be different form each other, it is necessary to investigate the thermal deformation characteristics of the heating machine to be used in the automation system. And their characteristics may be updated as new information about thermal deformation by heating is accumulated. In this paper, data base system has been constructed based on the results of experiments and numerical analyses, which will be used in deriving the deformation estimation formula. The computer code which can automatically derive the deformation estimation formula has been also developed. This paper also illustrates how the formula is updated as experimental data are added. From the present findings, it can be said that the automatic deriving procedure may be important in the automated plate forming system since the heating line information to be generated must be directly influenced by the deformation estimation formula.

• Computers and Concrete
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• 제10권2호
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• pp.121-133
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• 2012

Structures suffer from damages in their lifetime due to time-dependant effects, such as fatigue, creep and shrinkage, which can be expressed by concrete strains. These processes could be seen in the context of strain estimation of pre-stressed structures in two phases by using numerical methods. Their aim is checking and validating existing code procedures in determination of deformations of pre-tensioned girders by solving a system of nonlinear equations with strains as unknown parameters. This paper presents an approach based on the Newton-Raphson method for obtaining the stresses and strains in middle span section of pre-stressed girders according the equilibrium state.