• 한국자동차공학회논문집
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• 제21권5호
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• pp.130-135
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• 2013

Until now, passenger airbag design is based on the referred car design and many repetitive crash tests have been done to meet the crash performance. In this paper, it was suggested a new design process of passenger airbag. First, key performance factors were determined by analyzing the injury risk effectiveness of each performance factor. And it was made a relationship between injury risk and performance factor by using the response surface model. By using this one, it can be predicted the injury risk of head and neck. Predicted injury risk of optimal design was obtained through this injury risk prediction model and it was verified by FE analysis result within 18% error of head and 9% error of neck. It was shown that a target crash performance can be met by controlling the key performance factors only.

• Smart Structures and Systems
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• 제32권4호
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• pp.235-251
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• 2023

A method that can estimate global deformation and internal forces using a limited amount of displacement data and based on the shape superposition technique and a neural network has been recently developed. However, it is difficult to directly measure sufficient displacement data owing to the limitations of conventional displacement meters and the high cost of global navigation satellite systems (GNSS). Therefore, in this study, the previously developed estimation method was extended by combining displacement, slope, and strain to improve the estimation accuracy while reducing the need for high-cost GNSS. To validate the proposed model, the global deformation and internal forces of a cable-stayed bridge were estimated using limited multi-response data. The effect of multi-response data was analyzed, and the estimation performance of the extended method was verified by comparing its results with those of previous methods using a numerical model. The comparison results reveal that the extended method has better performance when estimating global responses than previous methods.

• 한국지진공학회논문집
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• 제20권1호
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• pp.63-70
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• 2016

This study is the sequel of a companion paper (I. Algorithm) for assessment of the seismic performance evaluation of structure using ground motions selected by the proposed algorithm. To evaluate the effect of the correlation structures of selected ground motions on the seismic responses of a structure, three sets of ground motions are selected with and without consideration of the correlation structure. Nonlinear response history analyses of a 20-story reinforced concrete frame are conducted using the three sets of ground motions. This study shows that the seismic responses of the frames vary according to ground motion selection and correlation structures.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1712-1725
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• 2022

For improving the seismic performance of the nuclear power plant (NPP) piping system, attempts have been made to apply a dynamic absorber (DA). However, the current piping DA design method is limited because it cannot provide the globally optimum values for the target design seismic loading. Therefore, this study proposes a seismic time history analysis-based DA optimal design method for piping. To this end, the Kriging approach is introduced to reduce the numerical cost required for seismic time history analyses. The appropriate design of the experiment method is used to increase the efficiency in securing response data. A gradient-based method is used to efficiently deal with the multi-dimensional unconstrained optimization problem of the DA optimal design. As a result, the proposed method showed an excellent response reduction effect in several responses compared to other optimal design methods. The proposed method showed that the average response reduction rate was about 9% less at the maximum acceleration, about 5% less at the maximum value of the response spectrum, about 9% less at the maximum relative displacement, and about 4% less at the maximum combined stress compared to existing optimal design methods. Therefore, the proposed method enables an effective optimal DA design method for mitigating seismic response in NPP piping in the future.

• 한국지진공학회논문집
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• 제23권4호
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• pp.201-209
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• 2019

Response modification factors of school facilities for non-seismic RC moment frames with partial masonry infills in 'Manual for Seismic Performance Evaluation and Retrofit of School Facilities' published in 2018 were investigated in the preceding study. However, since previous studies are based on 2D frame analysis and limited analysis conditions, additional verification needs to be performed to further apply various conditions including orthogonal effect of seismic load. Therefore, this study is to select appropriate response modification factors of school facilities for non-seismic RC moment frames with partial masonry infills by 3D frame analysis. The results are as follows. An appropriate response modification factor for non-seismic RC moment frames with partial masonry infills is proposed as 2.5 for all cases if the period is longer than 0.6 seconds. Also if the period is less than 0.4 seconds and the ratio of shear-controlled columns is less than 30%, 2.5 is chosen too. However, if the period is less than 0.4 seconds and the ratio of shear-controlled columns is higher than 30%, the response modification factor shall be reduced to 2.0. If the period is between 0.4 and 0.6 seconds, then linearly interpolates the response correction factor.

• 한국재난정보학회 논문집
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• 제16권2호
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• pp.318-330
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• 2020

연구목적: 본 연구에서는 재난관리의 주체인 소방공무원들을 대상으로 정부의 재난대응역량과 재난관리체계의 법·제도적 적절성이 재난관리 운영성과에 미치는 영향을 검증하였다. 연구방법: 소방공무원을 대상으로 설문조사를 수행하였으며, 조사자료는 SPSS 25.0 프로램을 이용하여 통계적 분석을 수행하였다. 연구결과: 본 연구를 통해 나타난 주요 결과는 다음과 같다. 첫째, 정부의 지진 재난대응역량은 재난관리 운영성과 요인인 재난 사전예방준비 뿐만 아니라, 재난 사후대응관리에도 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 둘째, 지진 재난관리체계의 법·제도적 적절성은 재난관리 운영성과 요인인 재난 사전예방준비 뿐만 아니라, 재난 사후대응관리에도 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 결론: 본 연구를 통해 국내 지진대비 재난관리의 운영성과를 향상시킬 수 있는 중요한 정책적 시사점을 얻을 수 있었다.

• Korea-Australia Rheology Journal
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• 제21권4호
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• pp.289-297
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• 2009

We numerically analyzed flow characteristics of the polymer melt in the screw equipment using a proper modeling and investigated design parameters which have influence on the mixing performance as the capability of the screw equipment. We considered the non-Newtonian and non-isothermal flow in a single rotor equipment to investigate the mixing performance with respect to screw dimensions as shape parameter of the single rotor equipment and screw speed as process parameter. We used Bird-Carreau-Yasuda model as a viscous model of the polymer melt and the particle tracking method to investigate the mixing performance in the screw equipment and considered four mixing performance indexes: residence time distribution, deformation rate, total strain and particle standard deviation as a new mixing performance index. We compared these indexes to determine design parameters and object function. On basis of the analysis results, we carried out the optimal design by using the response surface method and design of experiments. In conclusion, the differences of results between the optimal value and numerical analysis are about 5.0%.

• 소음진동
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• 제9권3호
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• pp.554-564
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• 1999

This paper presents the analytical method to evaluate the seismic responses on steam turbine-generator rotor system. Deterministic analytical methods, such as response spectrum approach, modal superposition method and direct integration method, are used to calculate the seismic response. The computer software is also developed based on the methods then can be applied to estimate the seismic safety of turbine-generator rotor system for power plants. Numerical example of a steam turbine-generator rotor system of 1007MW nuclear power plant is presented. The aseismatic performance are checked by comparing maximum seismic deflection at bearing positions with bearing clearance.

• Journal of Animal Science and Technology
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• 제46권2호
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• pp.183-192
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• 2004

급성 기 반응중인 육계에서 사료 중 크릴 밀의 생산성과 SOD 활성에 미치는 영향을 조사하기 위하여 크릴 밀 A와 B를 이용한 실험 1과 크릴 밀 A를 이용한 확인 실험 2가 실시 되었다. 실험사료는 옥수수 대두박 위주의 기초 사료 와 기초 사료 중 대두박과 2.0%의 크릴 밀 A(수입) 또는 크릴 밀 B(수입)를 대치한 사료이다. 실험 사료를 1 일령 육계 병아리에 급여하여 Salmonella typhymurium lipopolysaccharide (LPS)를 복강 내 주입하여 급성 기 반응을 발생시킨 2 주령 육계의 생산성과 Superoxide dismu- tase(SOD) 활성에 미치는 영향을 Saline을 주입한 대조와 비교하였다. 증체량, 사료 섭취량 및 사료효율은 크릴 밀 A와 크릴 밀 B 사료를 급여한 육계사이에 차이가 있었다. 크릴 밀 사료를 급여한 육계에서 급성기 반응은 간장과 비장 무계를 높였다. 그리고 급성기 반응은 크릴 밀 사료를 급여한 육계 병아리의 간장과 적혈구 세포액의 MnSOD와 Cu/ZnSOD 활성을 높였다. PHA-p 반응에 미치는 크릴 밀 사료의 영향은 없었다. 크릴 밀 B는 면역반응 후 회복중인 육계의 생산성을 향상시켰으나 크릴 밀 A에서는 이러한 영향이 없었다. 이상과 같이 크릴 밀의 종류에 따라 급성기반응시 와 회복시의 생산성은 SOD 활성의 변화로부터 산화 스트레스의 영향을 받고 있다는 것을 시사하고 있다.

• 한국지진공학회논문집
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• 제17권2호
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• pp.89-95
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• 2013

Structures in a nuclear power system are designed to be elastic even under an earthquake excitation. However a structural component such as an isolator shows inelastic behavior inherently. For the seismic assessment of nonlinear structures, response history analysis should be performed. In this study, the response of base isolation system was analyzed by response history analysis for the seismic performance assessment. Firstly, several seismic assessment criteria for a nuclear power plant structure were reviewed for the nonlinear response history analysis. Based on these criteria, the spectrum matched ground motion generation method modifying a seed earthquake ground motion time history was adjusted. Using these spectrum matched accelerograms, the distribution of displacement responses of the simplified base isolation system was evaluated. The resulting seismic responses excited by the modified ground motion time histories and the synthesized time history generated by stochastic approach were compared. And the response analysis of the base isolation system considering the different intensities in each orthogonal direction was performed.