• Smart Structures and Systems
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• 제24권1호
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• pp.95-110
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• 2019

The semi-active impact damper (SAID) is proposed to improve the damping efficiency of traditional passive impact dampers. In order to investigate its damping mechanism and vibration control effects on realistic engineering structures, a 20-story nonlinear benchmark building is used as the main structure. The studies on system parameters, including the mass ratio, damping ratio, rigid coefficient, and the intensity of excitation are carried out, and their effects both on linear and nonlinear indexes are evaluated. The damping mechanism is herein further investigated and some suggestions for the design in high-rise buildings are also proposed. To validate the superiority of SAID, an optimal passive particle impact damper ($PID_{opt}$) is also investigated as a control group, in which the parameters of the SAID remain the same, and the optimal parameters of the $PID_{opt}$ are designed by differential evolution algorithm based on a reduced-order model. The numerical simulation shows that the SAID has better control effects than that of the optimized passive particle impact damper, not only for linear indexes (e.g., root mean square response), but also for nonlinear indexes (e.g., component energy consumption and hinge joint curvature).

• 한국기계가공학회지
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• 제21권8호
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• pp.93-98
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• 2022

Adiabatic blanking is a method to improve productivity through an autocatalytic cycle that occurs repeatedly through plastic deformation and thermal softening caused by impact energy. In this study, an axisymmetric analysis model comprising a punch, die, holder, and specimen was developed to confirm the temperature and deformation characteristics caused by an impact load. Through this, the impact energy, diameter of the punch, gap between the punch and die, and the effect of the fillet were analyzed. Because this process occurs in a very short time, adiabatic analysis can be performed using the explicit time-integration method. The analysis, confirmed that it is necessary to design a structure capable of increasing the local temperature and plastic deformation by controlling the impact energy, working area, gap, and the fillet.

• Journal of Korea Trade
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• 제27권3호
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• pp.1-20
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• 2023

Purpose - Using trade data from 2008 to 2019, this study analyzes the impact of trade facilitation on China's agricultural exports under the RCEP framework using a gravity model based on the level of trade facilitation in 13 RCEP countries. Design/methodology - This study constructs a complete set of trade facilitation index systems, comprehensively measures the trade facilitation level of RCEP member countries, and uses a gravity model to verify the critical role of trade facilitation level in enhancing the trade volumes of RCEP member countries. Findings - We found that trade facilitation has a significant impact on China's agricultural exports as a whole. The effect of each primary indicator varies in magnitude, with finance and e-commerce (F) having the most significant impact, followed by customs efficiency (C) and infrastructure development (1); the institutional environment has no significant effect. Originality/value - This study analyzes the impact of trade facilitation on China's agricultural exports from the perspective of exports, and uses the latest data to study the degree of the impact of trade facilitation in importing countries. Measures to jointly enhance trade facilitation among member countries under the RCEP framework are proposed.

• 한국정보시스템학회지:정보시스템연구
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• 제32권3호
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• pp.63-83
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• 2023

Purpose With the continuous growth of the OTT services market, trust issues are becoming increasingly important, but research on this topic is still in its infancy. The purpose of this study is to identify the structural relationship between information system quality and reuse intention of OTT services and to analyze the impact of trust and user satisfaction. Design/methodology/approach This study proposed a research model based on the information system success model. In this study, a survey was conducted among 236 Korean users who have used OTT services within the last six months. Findings The results of the analysis showed that text quality and visual quality had a significant impact on trust in OTT services, with text quality having the largest impact. System quality and text quality also had a significant impact on trust in OTT service providers. However, visual quality did not have a statistically significant effect on trust in the service provider. Trust in the OTT service and the service provider was analyzed to have a significant impact on user satisfaction. However, it did not have a statistically significant impact on reuse intention. These findings have important implications for improving trust in OTT services to increase users' reuse intentions. It is also expected to contribute to further expanding the field of OTT service research.

• 한국정보시스템학회지:정보시스템연구
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• 제33권1호
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• pp.115-131
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• 2024

Purpose This study aims to analyse the impact of the development of fintech and the emergence of internet primary banks due to the increasing use of smartphones on the performance of traditional local banks from both financial and non-financial perspectives. Return on equity (ROE) and return on assets (ROA) are used to assess the performance differences between the two types of banks and how these differences are affected by their financial characteristics. Design/methodology/approach Using return on equity (ROE) and return on assets (ROA) as indicators, we identified the differences in operating performance between the two types of banks. In addition, this study analysed the impact of financial characteristics on profitability through regression analysis with various control variables. We further studied the impact of non-financial characteristics (customer reviews, social media reactions, etc.) on operating performance. Findings The net interest margin ratio of local banks had a positive impact, while the marketable securities ratio of Internet primary banks had a negative impact. The non-financial analysis shows that the number of customer reviews and social media reactions have a significant impact on the performance of Internet primary banks, suggesting that customer satisfaction and positive market perception are important factors in the performance of Internet primary banks.

• 아태비즈니스연구
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• 제14권4호
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• pp.357-370
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• 2023

Purpose - This study examined the influence relationships between the impacts of tourism development, local attachment, and resident involvement and local residents' support and pro-environmental behavior intentions in Jeju Island. Design/methodology/approach - A questionnaire was distributed to the Jeju Island residents and 373 samples were used for the analysis. Findings - The results showed that the perceived positive impact of tourism development has a positive effect on local residents' support, while the negative impact has a negative effect. Local attachment has no significant effect on local residents' support, while local involvement positively affects local residents' support. The positive impact of tourism development has a negative effect on pro-environmental behavior intention, while the perceived negative impact has a positive effect. Finally, when analyzing the relationship between local attachment, local involvement, and local support for eco-friendly behavior intention, it was found that they all have a positive effect. Research implications or Originality - Theoretical and managerial implications and suggestions for future research are discussed.

• 대한안전경영과학회지
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• 제6권1호
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• pp.311-323
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• 2004

This paper is to study the energy absorption characteristics of CF/Epoxy(Carbon Fiber/Epoxy Resin) laminated shell with the various curvatures subjected to transverse impact loadings under the low impact velocity in consideration of design of structural members for use of transportation machine, which are consisted of the characteristics of high stiffness, strength and lightweight. The curvature radius are associated with the energy absorption characteristics of CF/Epoxy laminated shell which is brittleness material. In all tests, maximum load of CF/Epoxy laminated plate is higher than that of laminated shell with curvature, but maximum deflection is lower. And then absorbed energy of laminated shell with curvature is higher than laminated plate(curvature radius is unlimited), As curvature radius is increased, the absorbed energy is increased in laminated shell with curvature.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.382-399
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• 2011

Impact factor of concrete and ballast track which has been used in Korea railway was applied to equation (1+0.513V/100) from AREA. As the use of this equation, overcapacity of track design might be occurred. Therefore, this study compared impact of ballast track (well, bad) and concrete track (sleeper embeded system, rail floating and sleeper floating) by field test to analyzing dynamic effect of track structure's characteristic and wheel load on service line. In addition, it suggested a method to generate reasonable track impact factor on each track type.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년도 추계학술발표대회 논문집
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• pp.257-262
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• 2009

In green building certificated housing complex, although various planning factors in terms of 'Energy resource and Environmental impact' were adopted, the residents' consciousness for their economical and psycholgical effect has not been found. Therefore, the purpose of this study was to find out the usability of environment-friendly factors, with regard to the aspects of 'energy resource and environment impact' and residents, consciousness for them in order to provide the useful information to design the user-oriented green building house complex better than previous ones. the finding were summarized as follows: 1)Increasing awareness of 'green building certificated housing complex', Resident should feel contribution to the environment. 2)When mass housing planning, the development of sensible certification is required. 3)Green building certificated housing complex should change from 'certification for the Financial compensation' to 'certification for the Contribution to the environment'.

• 환경영향평가
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• 제12권5호
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• pp.369-382
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• 2003

Natural resources managers have considered the landscape without detailed consideration of aesthetic values of the landscape and geomorphological significance of unique landforms. Since EIA system was introduced in 1981, values associated with landscape protection have been neglected at best compared with those values traditionally attributed to environmental protection, including clean air, water quality and species protection. Black top highways are being built without consideration of harmful effects to the sea cliffs. Sea walls and tetrapod are being installed to protect the coastal towns and fish markets for tourist. However, beach itself are experiencing accelerated erosion due to the shortage of proper coastal engineering expertise. Hotels and condominiums are under construction on a massive scale around the national parks, which substitute the scenic ridges with concrete profiles. To protect the scenic beauty of national parks, their design and construction material should be more harmonious with the surroundings. Therefore, visual impact assessment should be applied both within the national park boundary and beyond to enhance the aesthetic values of national parks.