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        검색결과 6,705

        192.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Strong ground motions at specific sites can cause severe damage to structures. Understanding the influence of site characteristics on the dynamic response of structures is crucial for evaluating their seismic performance and mitigating the potential damage caused by site effects. This study investigates the impact of the average shear wave velocity, as a site characteristic, on the seismic response of low-to-medium-rise reinforced concrete buildings. To explore them, one-dimensional soil column models were generated using shear wave velocity profile from California, and nonlinear site response analyses were performed using bedrock motions. Nonlinear dynamic structural analyses were conducted for reinforced concrete moment-resisting frame models based on the regional information. The effect of shear wave velocity on the structural response and surface ground motions was examined. The results showed that strong ground motions tend to exhibit higher damping on softer soils, reducing their intensity, while on stiffer soils, the ground motion intensity tends to amplify. Consequently, the structural response tended to increase on stiffer soils compared to softer soils.
        4,000원
        193.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To analyse the relationship between above-ground carbon stocks, species diversity and broadleaved forests structural diversity of South Korean forests, we collected vegetation inventories from environmental impact assessment projects over the past 10 years. The available data were selected and organised including tree species, DBH and area each projects. The data was classified by forest type, aboveground carbon stocks were calculated and compared, and the correlation between aboveground carbon stocks and biodiversity and structural diversity was analysed. The results showed that above-ground carbon stocks were higher in mixed forests and broadleaved forests and lower in needleleaved forests, similar to previous studies. However aboveground carbon stocks of mixed forests were higher in natural forests than in plantations. Aboveground carbon stocks in broadleaved forests were higher in plantations than natural forests, and there was no statistical different of between natural and plantations in needleleaved forest. This could be the result of a variety influences including biological and environmental factors in the study area, and further research is needed to analyse the effects on carbon sequestration. Correlation analysis showed no correlation between biodiversity and above-ground carbon stocks, but a positive correlation between structural diversity and above-ground carbon stocks. This indicates that above-ground carbon stocks in forests are associated with unevenness diameters and the proportion and evenness of tree species by diameter. In addition, it has been analysed that the high succession stages in forest have higher species diversity and structural diversity, and greater efficiency in the utilization of resources required for plant growth, leading to increased plant productivity and storage. Considering that the study sites were young forests with an average DBH of 14.8~23.7 cm, it is expected that carbon stocks will increase as biodiversity and structural diversity increase. Further research is needed to develop techniques to quantitatively assess the relationship of diversity to carbon stocks for policy use in assessing and increasing carbon stocks in forests.
        4,200원
        194.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dynamic responses of nuclear power plant structure subjected to earthquake loads should be carefully investigated for safety. Because nuclear power plant structure are usually constructed by material of reinforced concrete, the aging deterioration of R.C. have no small effect on structural behavior of nuclear power plant structure. Therefore, aging deterioration of R.C. nuclear power plant structure should be considered for exact prediction of seismic responses of the structure. In this study, a machine learning model for seismic response prediction of nuclear power plant structure was developed by considering aging deterioration. The OPR-1000 was selected as an example structure for numerical simulation. The OPR-1000 was originally designated as the Korean Standard Nuclear Power Plant (KSNP), and was re-designated as the OPR-1000 in 2005 for foreign sales. 500 artificial ground motions were generated based on site characteristics of Korea. Elastic modulus, damping ratio, poisson’s ratio and density were selected to consider material property variation due to aging deterioration. Six machine learning algorithms such as, Decision Tree (DT), Random Forest (RF), Support Vector Machine (SVM), K-Nearest Neighbor (KNN), Artificial Neural Networks (ANN), eXtreme Gradient Boosting (XGBoost), were used t o construct seispic response prediction model. 13 intensity measures and 4 material properties were used input parameters of the training database. Performance evaluation was performed using metrics like root mean square error, mean square error, mean absolute error, and coefficient of determination. The optimization of hyperparameters was achieved through k-fold cross-validation and grid search techniques. The analysis results show that neural networks present good prediction performance considering aging deterioration.
        4,000원
        195.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to examine the determinants of management performance in the remaining offshore fishing industry after the resource management-oriented fisheries structure improvement policy by the fisheries vessel buy-back program and Total Allowable Catch (TAC). The results of the analysis of the determinants of management performance of offshore fishing can be summarized as follows. First, based on the management performance determinant model of offshore fishing, it is confirmed that the government's resource-managed fishing structure improvement policy, such as the fishing boat reduction project and the TAC policy, is improving the management performance of the resource-managed remaining fishing boat. Second, looking at the specific management performance determinants based on the management performance model of offshore fishing, the leverage ratio (TLTA), which is the total debt ratio, shows a statistically significant positive (+) relationship with management performance, which increases management performance directly proportional to the leverage ratio. The increase in the leverage ratio (total debt ratio) was expected to lead to a high interest cost burden, resulting in a reverse (-) financial leverage effect; however, rather a positive (+) financial leverage effect occurred with a high profit covering interest costs. The total catch (TCATCH) has a positive (+) relationship with management performance at a statistical significance level of less than 1%, indicating that an increase in catch is improving or increasing the management performance of fishing companies. The selling price (UPRICE) shows a positive (+) relationship with management performance at a very high statistical significance level of less than 1%, and it can be seen that high fishing prices are a major factor in improving or increasing the management performance of offshore fishing. On the other hand, fishing vessel tonnage (TON), fishing vessel horsepower (RHP), and operating days (WDAYS), which indicate have a statistically significant negative (-) relationship with management performance, which deviates from the existing fisheries common sense that the size of fishing vessel tonnage and fishing vessel horsepower and the increase in the number of operating days is proportional to management performance. As a result of the increase in fishing vessel tonnage, horsepower, and the number of operating days, it was confirmed that the higher the fishing cost, such as oil costs, is worsening the management performance of fishing companies. Participation in TAC has a statistically significant positive (+) value with management performance, indicating that the remaining offshore fishing companies participating in TAC are improving or increasing management performance compared to offshore fishing companies that do not. Third, there are conflicting results depending on the industry as a result of estimating the management performance determinants of offshore fishing by TAC participation, and TAC participation had a negative impact on management performance in anchovy boat seine and southern west sea bottom trawl in fishing industry while TAC participation had a positive impact on management performance in large stow nets on anchor in fishing industry.
        4,500원
        196.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effects of social responsibility activities on consumer attitudes, product evaluation, corporate support, and corporate trust through structural equations and path analysis. Corporate social responsibility activities were divided into five areas: consumer and environmental protection, social contribution, cultural business, and economic responsibility, and the relative impact on consumer attitudes was considered. The results and strategic implications of this study are as follows. The same results as in previous studies confirmed that the performance of corporate social responsibility activities induces positive attitudes and behaviors of consumers. It proved that the performance of corporate social responsibility activities leads consumers to form a positive attitude, which can eventually be transferred to products and corporate images by a halo effect, leading to product evaluation, corporate support and trust. In addition, the composition dimension and measurement items of corporate social responsibility activities were re-verified, and from a consumer point of view, it was confirmed that social responsibility activities include not only economic activities, but also activities that contribute positively, such as social contribution, support for local and cultural projects, and actions that do not harm society as a whole, such as protecting consumer rights and protecting the environment.
        4,200원
        197.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although concerns about overheating of the franchise industry's market structure continue to be raised, there are few studies that analyze the market structure of the franchise industry and suggest practical use. Most existing studies mainly analyze the market structure of other industries using industrial concentration(HHI) as an indicator of market competition intensity from the perspective of industrial organization theory. This study seeks to present a market structure analysis method that is different from existing methods. Considering practical application, this study presented a method to analyze the market structure that combines industry concentration(HHI) analysis and matrix analysis of the franchise industry. First, the industry concentration(HHI) and operating profit ratio(SMR) of 15 major industries in the franchise industry were analyzed in a time series manner (2014-2019). Second, using industrial concentration and operating profit ratio(SMR) as two variables on the x-axis and y-axis, a two-stage matrix analysis was used to understand the market structure characteristics of 15 industries at a glance. Third, a method of utilizing the matrix analysis results for practical decision-making was presented.
        4,500원
        198.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 애니매이션 『진격의 거인』 속 관계들을 프로이트의 구조적 관점을 통하여 21세기 현재 우리 나라에서 보여지는 MZ세대의 특징과 연결해보고자 하였다. 연구 결과 첫째, 이드 충동으로써의 에렌은 현재의 만족만을 추구하는 MZ세대의 부정적 측면으로 나타나므로 계획하고 조 절할 수 있는 자아의 능력이 필요하다. 둘째, 박해적 초자아로써의 마레 는 MZ세대의 부모의 욕구에 동일시 되는 것으로 나타나므로 무의식적 죄책감이 자극된 초자아의 형성이 아닌 긍정적 초자아의 형성이 필요하 다. 셋째, 마비된 자아로써의 벽 안 인류는 MZ세대의 기본적인 욕구를 포기하는 것으로 나타나므로 이드 충동의 추구가 아니라 초자아를 완화 하고 자아를 강화하는 것이 필요하다. 따라서 MZ세대는 자아를 강화하 기 위해 자신이 진정으로 원하는 것과 할 수 있는 것이 무엇인지를 찾아 야 하며 사회는 MZ세대를 이해하는 관심을 통하여 성숙하고 성장하여야 한다.
        5,500원
        199.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is about the design of an elastic support system to isolate the structural noise of the low accumulator of the naval artillery among the equipment mounted on a warship. As the structural noise measurement value of the low accumulator transmitted to the ship exceeded the standard value, a method of applying an elastic mount between the equipment and the ship was devised to isolate the structural noise. By calculating the target vibration isolation efficiency, the vibration isolating system was designed in consideration of design factors such as the system's natural frequency and static displacement. Finally, the performance of the structural noise reduction of the designed vibration isolating system was verified by evaluating the structural noise transmitted to the foundation plate of the equipment from the low accumulator to which designed elastic support system was applied.
        4,000원
        200.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The government declared ‘2050 carbon neutrality’ as a national vision in October 2020 and subsequently pursued the establishment of a ‘2050 carbon neutrality scenario’ as a follow-up response. Hydrogen is considered as one of the most promising future energy carriers due to its noteworthy advantages of renewable, environmentally friendly and high calorific value. Liquid hydrogen is thus more advantageous for large-scale storage and transportation. However, due to the large difference between the liquid hydrogen temperature and the environment temperature, an inevitable heat leak into the storage tanks of liquid hydrogen occurs, causing boil-off losses and vent of hydrogen gas. Researches on insulation materials for liquid hydrogen are actively being conducted, but research on support design for minimal heat transfer and enhanced rigidity remains insufficient. In this study, to design support structures for liquid hydrogen storage tanks, a thermal-structural coupled analysis technique was developed using Ansys Workbench. Analytical models were created based on the number and arrangement of supports to propose structurally safe support designs.
        4,000원