• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.4
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• pp.106-113
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• 2002

In spacecraft system, structure subsystem has the mission of supporting all the components safely under various space environmental conditions. The safety of spacecraft structure is finally verified from the coupled load analysis, which is a branch of load analysis which combines the launch vehicle and satellite. This study introduces the optimization algorithm to reduce the weight of spacecraft structure under launch environmental conditions directly. The acceleration responses are obtained by the introduction of coupled load analysis, which lead to check the failure of spacecraft structural members. The results show a 12% saving of structural weight and this saving is mainly driven by the thickness of honeycomb core, which strongly affects the natural frequencies of platforms and panels.

• Journal of Digital Convergence
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• v.15 no.3
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• pp.295-300
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• 2017

The purpose of this study is to analyze the EBS special lecture, which is an educational application, from a user 's point of view and to propose a direction for improvement of the user experience according to the GUI design. Firstly, we surveyed the theoretical background and service situation through literature review, and secondly, we surveyed the user experience questionnaire based on 7 principles of honeycomb model of Peter Morville. As a result, the EBS special lecture showed improvement of GUI due to lack of visual part in addition to its use. Based on this research, I hope that the service for improvement of the user experience of the education application will be improved in the future and it will be helpful to study the educational application user experience to be conducted in the future.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.381-387
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• 2020

In order to study the similarities and differences of user experience of contactless retail services between Chinese and Korean users, this study focuses on E-mart 24 Self Convenience Store Gimpo DC Branch, Conducted in-depth interviews with Chinese and Korean users who have experience. The interviews are based on the 7 principles of Peter Morville's Honeycomb Model. As a result, the satisfaction of Chinese users is higher than that of Korean users. Human touch, and the desire for a faster society made Korean users more resistant to E-mart 24 Self Convenience Store. Chinese users raised concerns about the inconvenience of the system with little consideration for foreign users. It is expected that this study will help E-mart 24 Self Convenience Store to satisfy users from more cultural backgrounds.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.1
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• pp.26-32
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• 2005

In this paper, the effect of various regression models is investigated on structural optimization using the central composite method. Three bar truss and the upper platform of a satellite are optimized using various regression models that are polynomial, exponential and log functions. Response surface method is non-gradient, semi-global, discrete and fast converging in optimization problem. Sampling points are extracted by the design of experiments using the central composite method. Response surface is generated using the various regression functions. Structural analysis for calculating constraints is executed to find static and dynamic responses. From this study, it is verified that the response surface method has advantage in optimum value and computation time in comparison to other optimization methods.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.11
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• pp.1087-1093
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• 2010

The satellite thermal control H/W composed of two parallel channels working for heat pipe (HP) and phase change material (PCM) is suggested for the high heat dissipating component which works intermittently with short duty. In a limited point of view, the HP-PCM device is a kind of off-the-shelf component that requires no dedicated configuration and thermal designs to PCM. Therefore, it can be used with less impact on the program cost and schedule different from most of the PCM applications. In present study the typical honeycomb structure radiator applying the HP-PCM device is designed and the detail thermal math model is developed for numerical analyses. The result comparison between without and with PCM shows that the HP-PCM device redistributes the peak heat around the whole mission period through the alternate melting and freezing of PCM, and, as a result, the maximum and minimum temperatures are effectively alleviated. The drawback of PCM application due to low thermal conductivity can be successfully resolved by means of parallel arrangement of HP channel.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.431-436
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• 2016

Web-toon is provided to users in the form of Web-toon and The users are steadily rising and increasing amount of using time until today. Web-toon has become a popular pastime among smartphone users. Therefore, when providing services, Web-toon application should be made with an appropriate system so that it can be easily used, and considering problems that users may have while using the application, it should help users have better experiences. With Naver Web-toon and Lezin Comics as subjects, user experiences of teenagers were analyzed with questionnaires based on Honeycomb model of Peter Morville. The score of Naver Web-toon was higher than Lezin Comics after user experience assesment, and usability and accessibility as important factors turned out to be influential to teen-aged users who use Web-toon services.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.409-414
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• 2018

In China, the usage of smart speaker is continuously increasing. In this study, it is aimed to research on the user experience of the Chinese smart speaker. Therefore, we did literature research followed with theoretical background of smart speaker, and did case study of worldwide popular smart speaker brands. On this basis, we conducted in-depth interview with 8 users who have experienced with the top-selling Chinese smart speaker product "Tmall Genie" and "Mi AI speaker". The interview is based on 7 principles named Honeycomb model, which created by Peter Morville. As a result, users' discomfort was found in the functional part and the usability part of the smart speaker. Furthermore, the users were highly unsatisfied with the smart speaker in the credibility part. Accordingly, Chinese smart speaker should consider the user experience aspects to complement functional and usability parts for user.

• Journal of Digital Convergence
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• v.18 no.9
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• pp.331-336
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• 2020

The purpose of this study is to measure the satisfaction factors of user experience of 'Unlimited subscription service' among subscription services and analyze them based on economic and cultural perspectives. By recruiting the '20-'30s who had experienced using service, they attended a survey which was based on the reconstructed honeycomb model of Peter Morville. As a result of the survey, in terms of economic perspective, cost of service, and the ease of subscription inflow were the main satisfaction factors. From a cultural perspective, the familiarity with service and belief and experience of sharing content with people around them were the main satisfaction factors. Therefore, it can be inferred that the satisfaction of the user experience of the subscription service should be firstly satisfied with economic satisfaction, which leads to cultural satisfaction. This study is expected to be used as research data on user experience and satisfaction factors of unlimited subscription service.

• Aerospace Engineering and Technology
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• v.12 no.1
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• pp.213-220
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• 2013

Korean Lunar Explorer is planned to be launched in the 2020s according to national space development strategy. The Lunar Explorer will be developed as two unmanned light weight models: a lunar orbiter and a lunar lander. The Lunar Explorer's structure should be designed to have light weight due to constraints from launcher as well as to provide structural safety against launch load, in-orbit condition and landing condition and to serve accommodation space for mission equipment. Core technology related to structural development of lunar explorer should be developed in advance. Especially, for lunar lander, technology for developing landing gear which enables lander to land safely on lunar surface is required essentially. This paper deals with structural development of lunar lander ground test model including design, manufacturing and test.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.271-276
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• 2017

This project has been conducted to improve the usability of Chatbot Services such as Google(Allo) and Facebook M(Messenger. Based on the evaluation, this study aims to suggest the solutions to improve the usability of domestic Chatbot services and future directions for their development. It provides the overall understanding of the AI Chatbot service and the feature of Chatbot service through literature search. Furthermore, we summarized the current standing and the prospect of domestic messenger-based assistant Chatbot services. For conducting user evaluation, Peter Morville's honeycomb model is applied to in-depth user interviews. The followings are elements that could be amended to improve the service. The service should be incorporated by intuitive elements for users' understanding its functions and eliminate any elements that interfere with usability. The accuracy should be increased to improve the user satisfaction. This research will provide the future guidelines to improve the usability of Chabot services through continuous evaluation by users.