• Earthquakes and Structures
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• 제22권5호
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• pp.475-485
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• 2022

This paper presents a comparative experimental study on structural behavior of the interlocking masonry walls under in-plane cyclic loading. The main purpose of this study is to increase lateral load-bearing capacities of masonry walls by using interlocking units. The interlocking units were designed by considering failure modes of masonry walls and produced using lightweight foamed concrete. To this end, three masonry walls which are hollow, fully grouted, and reinforced were constructed with interlocking units. Also, a traditional masonry brick wall was built for comparison reasons. The walls were tested under in-plane cyclic loading. Then, structural parameters of the walls such as lateral load bearing and total energy dissipation capacities, ductility, stiffness degradation as well as failure modes obtained from the tests were compared with each other. The results have shown that the walls with the interlocking units have better structural performance than traditional masonry brick walls and they may be used in the construction of low-rise masonry structures in rural areas to improve in-plane structural performance.

• Journal of Welding and Joining
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• 제33권4호
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• pp.50-56
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• 2015

In general, discontinuity of metallurgical and structural points of weld zone could decline the fatigue strength. For the lightweight trend, the AHSS application in automotive chassis is in-progress. However, there are few research reports on AHSS welds fatigue strength in especially automotive chassis parts. Therefore, in this study, we evaluated the effects of the factors affecting the AHSS welding fatigue strength. As the result, the stress concentration of weld bead is the most important factor for welding fatigue strength. For the enhancement of welding fatigue strength, we focused on reducing the stress concentration of the welding beads. So, we applied and proved the plasma welding process and GTAW (Gas Tungsten Arc Welding) dressing method. It was verified by uniaxial fatigue specimen, fatigue performance increased from 40 to 60% by applying TIG dressing method compared to the conventional GMAW (Gas Metal Arc Welding). These results could be recommended the enhancement of fatigue performance of AHSS.

• 한국해양공학회지
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• 제34권4호
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• pp.253-262
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• 2020

This study provides a comparative analysis of experiments-based enhancements and sensitivity evaluations for the structural design of an automatic ocean salt collector under various load conditions. The sizing variables of the structural members were considered as design factors. The strength and weight performances were selected as output responses. The design of experiments used in the comparative study consisted of the orthogonal array design, Box-Behnken design, and central composite design. The response surface model, one of the metamodels, was applied to the approximate model generation. The design enhancement performance metrics, including numerical costs and weight minimization, according to the design of experiments, were compared from the best design case results. The central composite design method showed the most enhanced design results for the structural design of the automatic ocean salt collector.

• 유통과학연구
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• 제20권7호
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• pp.1-9
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• 2022

Purpose: This study aims to examine the effect of intellectual capital on both internal and external collaboration and its impact on distribution performance enhancement in public sector. Research design, data, and methodology: The study applied quantitative approach with the help of AMOS Structural Equation Modelling. The unit of analysis is the Indonesian local government. The research involved 430 leaders from local government agencies as respondents. Results: This study found that intellectual capital positively influences both internal and external collaboration as well as distribution performance. Furthermore, the current research confirms the different effect of internal collaboration and external collaboration on distribution performance; internal collaboration positively affects distribution performance, while the external one does not. Eventually, internal collaboration mediates the indirect effect of intellectual capital on distribution performance, whereas the external collaboration does not. Conclusions: This study strengthens and complements the lean stream by confirming the role of intellectual capital as critical antecedent of internal collaboration, external collaboration, and distribution performance. Moreover, this research underlines the critical role of internal collaboration as the intercourse which supports distribution performance enhancement in public sector. Lastly, the study highlights the benefits of external collaboration in distribution practice if appropriately and wisely managed.

• 한국구조물진단유지관리공학회 논문집
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• 제4권1호
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• pp.139-145
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• 2000

In this experimental program specimens. designed by the test variables, such as percentage of steel fiber incorporated, were constructed and tested to evaluate the flexural performance of reinforced steel fiber concrete beams. Based on the test results reported in this study, the following conclusions are made. Comparing with the load-displacement relationship of standard specimen, specimen over 0.5% of steel fiber incorporated, could be improved significantly flexural performance, such as capacity, ductility, and crack pattern. As increasing in quantity of steel fiber incorporated(0.5%~2.0%), the flexural strength of each specimen was shown the enhancement of 13%~40% in comparision with the standard specimen BSS.

• Earthquakes and Structures
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• 제23권1호
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• pp.87-100
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• 2022

Limiting the displacement of seismic isolators causes a pounding phenomenon under severe earthquakes. Therefore, the ASCE 7-16 has provided minimum criteria for the design of the isolated building. In this research the seismic response of isolated buildings by Triple Friction Pendulum Isolator (TFPI) under the impact, expected, and unexpected mass eccentricity was evaluated. Also, the effect of different design parameters on the seismic behavior of structural and nonstructural elements was found. For this, a special steel moment frame structure with a surrounding moat wall was designed according to the criteria, by considering different response modification coefficients (RI), and 20% mass eccentricity in one direction. Then, different values of these parameters and the damping of the base isolation were evaluated. The results show that the structural elements have acceptable behavior after impact, but the nonstructural components are placed in a moderate damage range after impact and the used improved methods could not ameliorate the level of damage. The reduction in the RI and the enhancement of the isolator's damping are beneficial up to a certain point for improving the seismic response after impact. The moat wall reduces torque and maximum absolute acceleration (MAA) due to unexpected enhancement of mass eccentricity. However, drifts of some stories increase. Also, the difference between the response of story drift by expected and unexpected mass eccentricity is less. This indicates that the minimum requirement displacement according to ASCE 7-16 criteria lead to acceptable results under the unexpected enhancement of mass eccentricity.

• 통상정보연구
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• 제13권4호
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• pp.411-433
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• 2011

본 논문은 설문조사 자료에 기초하여 제조기업의 환경관리활동 즉, 규범준수활동과 혁신지향활동이 환경대응능력의 창출과 성과의 제고에 미치는 영향에 관한 연구모형을 설정하고, 구조방정식 모델을 이용하여 실증분석을 수행하였다. 분석결과, 환경문제와 관련된 시장압력에 대응한 기업의 자발적인 혁신활동은 기업의 환경대응 능력의 창출과 성과제고에 정의 영향을 미쳤다. 그렇지만, 규제압력 즉, 법적 요건에 순응하기 위한 목적의 규범준수활동은 환경대응능력의 창출과 성과제고에 기여하지 못하는 것으로 나타났다. 게다가 혁신활동을 통해 창출된 환경대응능력은 기업성과제고를 위한 중요한 원천이 되는 것으로 나타났다. 이러한 연구결과를 바탕으로 그 시사점과 향후 연구방향에 대해 토의하였다.

• 한국산학기술학회논문지
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• 제13권11호
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• pp.5558-5565
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• 2012

도로 방호울타리는 차량의 이탈을 방지하는 시설로, 도로의 형태나 제한속도 등을 기준으로 하여 7 종류의 방호울타리를 규정하고 있다. 하지만, 최근 차량의 성능이 향상되면서 과적, 과속의 위험이 있고, 국내외 방호울타리 관련 차량사고를 보면 추락사고가 빈번하게 발생하고 있어, 현재의 방호울타리 설계충격도가 다소 부족한 것으로 나타나고 있다. 본 연구에서는 고속도로에 주로 적용하는 SB5 강재 방호울타리와 SB6 콘크리트 방호울타리의 차량방호 성능을 검증하기 위하여 차량충돌해석을 수행하여, 방호울타리의 파괴 및 차량전도 조건을 산출하였다.

• Structural Engineering and Mechanics
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• 제20권6호
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• pp.727-745
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• 2005

The present study is an experimental investigation into the behaviour of high strength concrete square short columns subjected to biaxial bending moments and strengthened by GFRP laminates. The main objectives of the study are: to evaluate the improvement in the structural performance of HSC short square columns subjected to small biaxial eccentricity when strengthened by externally applied FRP laminates, and to investigate the optimum arrangement and amount of FRP laminates to achieve potential enhancement in structural performance especially ductility. The parameters considered in this study are: number of FRP layers and arrangement of wraps. The load eccentricity is kept corresponding to e/t = 0.125 in two perpendicular directions to the columns principal axes, and the wraps are applied in single or double layers (partial or full wrapping). In the present work, test results of five full scale concrete columns are presented and discussed. The study has shown that FRP wraps can be used successfully to enhance the ductility of HSC columns subjected to biaxial bending by 300%.

• 한국구조물진단유지관리공학회 논문집
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• 제5권2호
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• pp.121-128
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• 2001

Reinforced concrete frame buildings in regions of low to moderate seismicity are typically designed only for gravity loads with non-seismic detailing provisions of the code. These buildings possess strong beam-weak column, which brings about the brittle structural performance like the column sidesway failure mechanism during the strong lateral load. The objective of this paper is to enhance the column strength and deformation capacity for reconfiguring the structural failure mode by averting a column soft-story collapse and moving to a more ductile beam-sides way mechanism suing new reinforcing materials. Aramid fiber sheet and reinforcing rod-composite materials was used for this purpose. The column was modeled by the 2/3 scale experimental specimen retested. According to the concept of the capacity design, the damaged column was strengthened by the column jacketing using new reinfocing materials such as rod-composite materials. In conclusion, the improvement of the flexural strength is observed and the capacity of the energy dissipation and the ductility is enhanced, too.