• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.12-20
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• 2024

The application of reinforcement design to ensure the structural safety of electronics in small satellites is limited by the spatial constraints of the satellite structure during launch vibrations. Additionally, a reliable evaluation approach is needed for mounting highly integrated devices that are susceptible to fatigue failure. Although the Steinberg fatigue failure theory has been used to assess the structural integrity of electronic devices, recent studies have highlighted its theoretical limitations. In this paper, we propose a structural methodology based on the critical strain theory to design the digital control unit (DCU) of the X-band SAR payload component for the small SAR technology experimental project (S-STEP), a small satellite constellation. To validate the design, we conducted modal and random analyses using simplified modeling techniques. Based on our methodology, we ultimately demonstrated the structural safety of the electronics through analysis results, safety margin derivation, and functional tests conducted both before and after the launch test.

• Journal of The Korean Association For Science Education
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• v.44 no.1
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• pp.29-38
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• 2024

In this study, we explored the philosophical perspective of Ian Hacking on experimentation and discussed its potential impact on science education in schools. Traditionally, many philosophers have advocated a theory-driven view of experimentation, emphasizing its importance primarily in validating theories. Similarly, in the context of education, the prevailing perspective has been to focus on experimentation primarily as a means of confirming and proving theories. However, in contrast to this theory-driven perspective, philosophers like Hacking have proposed that experimentation itself possesses autonomy and vitality. Through their discussions, they have brought to light the significance of previously overlooked elements in experiments, such as tool usage, materials, and the involvement of scientists. They have prompted a reevaluation of the role and importance of experiments in scientific activities. Therefore, in this study, we consider the application of this philosophical standpoint to school experimental education. We anticipate that the phenomenon-centered perspective we propose in this research will be beneficial for teaching scientific practices, including tool usage, the involvement of experimenters, and modeling activities.

• Management & Information Systems Review
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• v.30 no.3
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• pp.57-84
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• 2011

In this study, a model of the effects of advertising on an employee's organizational identification was proposed by combining psychological contract, social identity theory with hierarchy of effect model. Our empirical results show that perceived accuracy of message in advertising affected attitude toward advertising significantly while perceived relevance of message with respondents' department didn't. And attitude toward advertising influenced employee's organizational identification. New findings in this research is the role of attitude toward advertising influencing on employee's organizational identification as mediator variable.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2020-2028
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• 2013

In this paper, we propose a novel analysis and design methodology based on complex network theory for wireless large-scale ad hoc networks. We also enhance the conventional analysis methods which does not sufficiently consider the effect of the wireless communication channels and extend the existing random graph theory by reflecting the wireless communication environments. As a main result, the effect of the network topology such as average degree of each communication node on the network capacity through extensive computer simulations.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.1
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• pp.63-69
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• 2009

Gas volumetric fractions and pressure loss are very important parameters in understanding and predicting gas-liquid two-phase flows. They are also essential to design large heat exchanging system in many industries, boiler and refrigerating systems mounted at ships. This paper therefore presents a theoretical method of predicting the pressure loss and gas volumetric fractions in gas-liquid two-phase flows for the whole range of pipe inclinations. The theoretical analysis is based on the two-fluid stratified flow model. It also provides the results of the comparisons between this theoretical analysis results and previous experimental results.

• Proceedings of KOSOMES biannual meeting
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• 2005.11a
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• pp.65-69
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• 2005

The theoretical propagation modes of radio waves in the area of Line of Sight(LOS) within Fresnel zone are searched for the available detection ranges in a Marine RFID (Radio Frequency Identification). The structural LOS model to Earth's curvature is proposed and, the calculation method of horizontal distance in a specific radio frequency is also considered in this work As studying results, it is found that the height of antenna to cover the detection ranges and the influences of detection ranges by weather environments can be analyse with the theoretical methods.

• Journal of Korean Library and Information Science Society
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• v.39 no.4
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• pp.237-260
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• 2008

This study is designed to find out what kinds of factors influence the application of RFID system to the library. This study is followed by theoretically reviewing the RFID and the application RFID system to the library. Theoretical study models are developed by expanding the social influence, perceived risk, job relevance, support, and self-efficacy after Based on Technology Acceptance Model that provides useful theoretical foundations for setting the perceived usefulness, perceived ease of use, and intention of application to the library of RFID system as the core of a study model. The affecting factors of application of the RFID system to the library are presented by empirically studying this study model.

• Journal of the Korean Society for Railway
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• v.11 no.1
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• pp.45-53
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• 2008

With the growing international consensus regarding sustainable development of transportation, the plan of transportation infrastructure needs to meet various requirements toward enhancing environmental conditions. Accordingly, the upcoming long-term plan of high-speed rail network has to be reflecting the sustainability of transportation systems. In this paper, we demonstrate an application of methodologies based on multi-attribute utility theory for determining priorities of sustainable high-speed rail investment. The proposed methodologies identify indicators for sustainable transportation systems such as economic, environmental, and social ones and then, evaluate priority for planning a long-term sustainable high-speed rail network by comparing the relative importance among indicators. This will help transportation agencies to prioritize high-speed rail investment toward sustainable transportation systems.

• Journal of the Korea Convergence Society
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• v.7 no.5
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• pp.7-13
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• 2016

Since a smart phone became popular that leads mobile era, we've faced diverse life style changes. Particularly, a mobile messenger which changes communication method from voice and video call to text based multi media messenger, leads new gift-giving culture called mobile voucher gift-giving. Although many researches have validated diverse models about digital voucher, this research utilize the model which divide motivation of gift-giving from three theories: gift-giving motivation theory, technology acceptance model, and consumer value theory. The purpose of this research is not only validate the model but also grouping by giving frequency of samples and validate disparity among groups. In conclusion, there are three groups founded and shows difference motivations.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.1
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• pp.129-138
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• 2000

Composites are finding increasing use in a wide variety of engineering applications due to their outstanding mechanical properties. A number of studies have focused on the development of new materials as well as the response of composite structures to static and dynamic loads by assuming the external driving forces to be deterministic. However, there ate many situations in practice where the exciting forces vary randomly. In this work, the nonlinear response of laminated composite plates excited by stochastic loading is studied by the finite element method. Classical, first-order and third-order shear theories for plates are used in the finite element formulation. Since most composites exhibit significant nonlinearity in the shear stress-strain law, this is included in the present analysis.