• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2840-2851
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• 2022

Electric boilers (EBs) are the backup steam source for the auxiliary steam system of high-temperature gas-cooled reactor nuclear power plants. When the plant is in normal operations, the EB is always in hot standby status. However, the current hot standby operation strategy has problems of slow response, high power consumption, and long operation time. To solve these problems, this study focuses on the optimization of hot standby operations for the EB system. First, mathematical models of an electrode immersion EB and its accompanying deaerator were established. Then, a control simulation platform of the EB system was developed in MATLAB/Simulink implementing the established mathematical models and corresponding control systems. Finally, two optimization strategies for the EB hot standby operation were proposed, followed by dynamic simulations of the EB system transient from hot standby to normal operations. The results indicate that the proposed optimization strategies can significantly speed up the transient response of the EB system from hot standby to normal operations and reduce the power consumption in hot standby operations, improving the dynamic performance and economy of the system.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.198-205
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• 2022

Along with a variety of coding education, physical computing education for controlling various sensors is being actively conducted for elementary, middle, and high school students in line with the era of the fourth industrial revolution. A problem with physical computing education using Arduino is pin connection errors between Arduino and various sensors. Most of the students who come into contact with the Arduino for the first time often do not know the purpose of the Arduino pin and the connection position of the pin. Also, hardware built with incorrect pin connections to the Arduino board often does not work properly. If this case continues, students will lose interest in coding education. Therefore, in this paper, we implemented an augmented reality application that informs the connection process of the Arduino board and the sensor during physical computing coding education using Arduino, and designed and implemented educational content for the Arduino pin position and connection process. First, we explain the role of the Arduino board and the sensor and the location of the pins. After that, the students run the educational augmented reality educational content using their smartphones and check the correct pin connection process between the Arduino and the sensor. In the physical computing education, augmented reality content is used to increase the understanding and immersion of the class. It is expected that the educational effect will also increase by inducing fun and interest in physical computing coding education.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.101-110
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• 2022

This study sheds light on the Instagrammable features and viewing experiences of . A research model and hypotheses are formulated using variables including Experience Quality (EQ), Perceived Value (PV), Attitude toward AWA (ATAWA) and Behavioral Intention toward AWA (BITAWA). Although AWA has strong the Instagrammable features in terms of PV, it provides aesthetic or healing experience rather than a pleasure. PV has a significant correlation with DOS and DOI, but it does not influence on BITAWA. In addition, DOS has a positive impact on the increase in DOI, length of viewing time and intention to upload and share photos on Instagram.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.193-199
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• 2023

The purpose of this paper is to solve the difficulties of experimental education by using AR science experiments in class, prevent safety accidents, and maximize immersion through multilateral experiences to induce active participation. The problems with educational realistic content currently being developed were (1) the lack of exploratory content practically available in class, (2) the end of most applications with one-time content, and (3) the inability to interact between teachers and students. To solve these problems, we develop AR experiments according to the curriculum. It is developed so that teachers and students can use it together through the function that teachers can manage students.

• Steel and Composite Structures
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• v.48 no.3
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• pp.251-262
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• 2023

There are many examples of steel structures subjected to severe environmental conditions with bolted connections directly exposed to extreme climatic agents such as freeze-thaw cycles or low temperatures. Some examples are: steel bridges, mining transfer towers, wind towers... These service conditions neither are included in Eurocode 3 or EN1090-2, nor there are references in other international standards. In this experimental research, 46 specimens of non-slip joints with HV M20 bolts and four different types of contact surfaces have been studied. Half of the specimens were subjected to fourteen twelve-hours freeze-thaw cycles, with periodic immersion in water and temperature oscillation. Subsequently, half of the connections were subjected to a slip test under monotonic load at temperature of -20 ± 0.5 ℃ and the other half at room temperature. The results were compared with others equal joints not subjected to freeze-thaw cycles and kept at room temperature for the same time. This finally resulted in 4 sets of joints by combining the freeze-thaw degradation or not with the low-temperature conditions or not in the slip testing. Therefore, a total of 16 different conditions were studied by also considering 4 different contact surfaces between the joined plates in each set. The results obtained show influence of environmental conditions on the slip resistant capacity of these joints.

• 한국정보교육학회:학술대회논문집
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• 2021.08a
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• pp.341-348
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• 2021

With the advent of the pandemic era, non-face-to-face classes are being conducted, and many studies are being conducted on the effects of non-face-to-face classes in many subjects. Since the programming class is a subject that combines knowledge transfer and practice. In the case of non-face-to-face classes, I wanted to know how students perceive them through a survey. The number of students who answered that traditional face-to-face classes were good in terms of ease of question and answer, understanding of class content and immersion in class, and more students answered that non-face-to-face classes were good in terms of securing practice time and class control. It is expected that using the results of this study will help plan effective programming lessons.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.351-352
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• 2021

Due to the recent rapid change in the social environment due to Corona 19, the need for non-face-to-face/contact-based information exchange technology is rapidly emerging. Due to these changes, the development of an alternative system using a sense of immersion and a sense of presence is urgently required. In this study, in order to implement a video conferencing system, we implemented a technology for transmitting large-capacity 3D data in real time without delay. For this, the applied algorithm of GAN, the latest deep learning algorithm of the unsupervised learning series, was used.

• Journal of Practical Engineering Education
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• v.15 no.2
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• pp.467-474
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• 2023

Disaster safety education that can respond when a disaster occurs is very important in Korea, where many human resources are generated due to safety insensitivity. Recently, with the development of virtual reality devices and manufacturing technology, the possibility of using a training system incorporating virtual reality technology in the field of safety education is attracting attention. The virtual training system is very effective for training and education because it has an excellent sense of immersion and allows you to experience various disaster situations without time and space limitations. In this study, cases of disaster safety virtual training contents in Korea are collected and investigated, and the current status of domestic disaster safety virtual training contents is identified and analyzed to identify problems and suggest improvement plans.

• Journal of Research and Publication Ethics
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• v.5 no.1
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• pp.19-27
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• 2024

Purpose: To prevent and respond to youth sexual problems that are becoming more serious with digital development, this study sought to develop a sex education program that applies gamification as an effective method for youth who are digital natives. Research design, data and methodology: To develop a sex education program for teenagers, elements of gamification were considered based on Dick and Kerry's teaching system design model. The learning content reflected UNESCO's 'Comprehensive Sex Education Guidelines'. In addition, it was designed to enable students to learn about ethics and morals from a social and emotional aspect. Results: A four-session distance learning sex education program was developed for first-year high school students. To learn about gender sensitivity, sexual relationships, sexuality, and healthy sexual behavior, we developed a story that reflects the mission and quest for sex education. It included leaderboards, time limits, and levels, and also utilized mechanics such as points and items. Edutech tools include video content, Google Sheets, Zoom, Padlet, and Mentimeter. Conclusions: This study aims to improve learning effectiveness, satisfaction, and immersion by developing a sex education program for youth using gamification that promotes active learner participation and motivation.

• Corrosion Science and Technology
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• v.23 no.1
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• pp.54-63
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• 2024

This work investigated the influence of concentration and applied potential on the characteristics of zinc powder (purity, apparent density, morphology, particle size distribution, and particle zeta potential) produced by the electrochemical process from waste brass. High-purity zinc powder is obtained using selective leaching of industrial brass waste in acidic, neutral, and alkaline solutions. The free immersion method with and without voltage using linear polarization technique is used. In the electrochemical process, hydrochloric acid HCl in three different concentrations (0.1, 0.2, and 0.3) M is used. The time and the distance between the electrodes are set to be 30 min and 3 cm, respectively. It has been found that the percentage purity is 98%, 96%, and 94% for the acidic, neutral, and alkaline solutions, respectively. In addition, the morphology of zinc powder analyzed by SEM was dendritic and mossy. It has been recorded that the purity of zinc increases with the increase of the concentration and applied potential. The highest value of purity for zinc powder was %98.58 in 1000 mV and 0.3M concentration for graphite cathode.