• Informatization Policy
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• v.21 no.1
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• pp.57-76
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• 2014

The purpose of this research is to investigate the role of social dimensions in predicting the intention to use SNS. We proposed an integrative SNS acceptance model based on the theory of planned behavior (TPB), the technology acceptance model (TAM), and the social influence theory. Included in the model are attitude toward SNS use, subjective norm, information cascades, and perceived behavioral control as antecedents to intention to use SNS. An empirical analysis was conducted using data collected from a questionnaire survey with 228 college students in Korea, and it yielded the following findings. First, the two social dimensions, namely subjective norm and information cascades, were found to have a significant positive relationship with the intention to use SNS. In particular, information cascade turned out to have the strongest impact of the three antecedents to intention to use SNS. Second, perceived usefulness and perceived ease of use were found to have a significant positive influence on the attitude toward SNS use.

• The Journal of Society for e-Business Studies
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• v.15 no.1
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• pp.39-60
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• 2010

It becomes common thing that many customers buy the goods through the online shopping mall as internet grows very fast. The information cascades that happen when a person imitates the other's acts also it occurs in online. Many people buy the goods referring on other people's purchasing experiences and such cases are spreading more and more. Through numerous existing researches, the researches in association with this issue have been studied on the information cascades effect on offline or online separately. The research of comparing the information cascades effects from the offline word of mouth (WOM) and the online review has not studied yet. On that reason this study shows that the online review induces the information cascades. We also compared the effects with information cascades effects from traditional offline word of mouth. In result of this study, the following points have been concluded. Firstly, we examined that information cascades was occurred through both the online review and offline word of mouth. Secondly, the information cascades effect through the online review is greater than through the offline words of mouth. It means the company has to understand the importance of the online review and manage it. Thirdly, the information cascades effects are occurred differently in accordance with the goods brands. Therefore a company has to know whether its products is superior to the competitor's one or not.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.10
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• pp.969-978
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• 2008

In a linear cascade experimental apparatus, when it adopts only few blades as well as satisfies the periodic condition between blades, it gives several advantages in experiment. In this study, wall design on a cascade experimental apparatus is conducted to obtain the periodic condition on two blades installed within a passage of which the width is double pitch. The Mach number difference on the blade surface obtained with the periodic and wall condition is chosen as an objective function, and twelve design variables which are related to the wall shape are selected. A wall shape is designed using a gradient-based optimization method. Adjustment of range and weighting function are applied to calculate the objective function to avoid unrealistic evaluation of the objective function. By applying these methods, the computed results show same flow structures obtained with the periodic condition.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.218-223
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• 1999

현재의 발전소 보일러 제어방식은 프로세스 성격에 따라 제어루프의 상태변수들을 근간으로 세부적인 독립된 제어루프별로 제어를 시행하는 개별 루프를 채택하고 있다. 발전소에서 사용하는 PID제어 방식은 각 부시스템들의 상태변수, 출력변수가 다른 부시스템의 선행신호가 되거나 기준신호가 되어 피드백제오, 피드포워드 제어와 캐스케이드 제어 등의 신호로 작용한다. 선행신호와 상태 궤환 신호는 다른 부시스템의 상태변수를 측정함에 의하여 결정되며, 상호연결 함수는 경험에 의한 함수 설정에 의해 결정된다. 본 논문에서는 먼저 화력발전소 보일러 제어시스템을 플랜트 변수들 사이의 인과관계를 표현하는 신호흐름도의 보일러 모델과 실제 발전소에 적용되고 있는 드럼 수위 제어기에 대해 기술한다. 그리고 현장에서 취득한 운전데이터를 이용한 보일러 드럼수위 제어계통의 모델링에 관한 내용에 대해 기술하고, 마지막으로 컴퓨터 시뮬레이션에 의한 제어루프의 모의실험 결과를 통해 제어기의 설계와 제어루프의 효용성을 보이고자 한다.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.527-536
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• 2022

The radiation shielding characteristic of neutron shielding material has been studied as the preliminary study in order to design cosmic-ray shielding material. Specially, Soft Magnetic Material, known to be effective in EMP and radiation shielding, has been investigated to check if the material would be applicable to cosmic-ray shielding. In this work, thermal neutron shielding experiment was conducted and the Monte Carlo N-Particle(MCNP) was applied to employ skymap.dat, which is cosmic-ray data embedded in MCNP. As a result, polyethylene, borated polyethylene, and carbon nano tube, containing carbon or hydrogen, have been found to be effective in reduction of neutron flux below 20 MeV (including thermal, epithermal, evaporation). In contrast, the materials composed of iron such as SS316 and Soft Magnetic Material show a good shielding performance in the cascade energy range (above 20 MeV). Since Soft Magnetic Material is consisting of 13% of boron, it can also decrease thermal neutron flux, so it is expected that it would show a significant reduction on the entire range of neutron energy if the Soft Magnetic Material is used with hydrogen and carbon, so called low Z material.