• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.6
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• pp.185-190
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• 2023

Recently, tracking radar requires the development of millimeter wave tracking radar to acquire target information with high resolution in various environments. The development of millimeter wave tracking radar requires the development of transmission and receiving components that can be applied to the millimeter wave tracking radar, as well as verification of the applicability of the tracking radar. In order to verify the applicability of the developed transmitting and receiving components, it is necessary to develop a signal acquisition device that can control the transmitting and receiving components using the operating concept of a tracking radar and check the status of the received signal. In this paper, we implemented a signal acquisition device that can confirm the applicability of components developed for millimeter wave tracking radar. The signal acquisition device was designed to process in real time the OOOMHz center frequency and OOMHz bandwidth signals input from 4 channels to verify the received signal. In addition, component control applying the tracking radar operation concept was designed to be controlled by communication such as RS422, RS232, and SPI and generation of control signals for the transmission and receiving time. Lastly, the implemented signal acquisition device was verified through a signal acquisition device performance test.

• Journal of the International Relations & Interdisciplinary Education
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• v.2 no.2
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• pp.81-95
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• 2022

The core of this study is to develop an edutech utilization program to be applied to 5th grade students by utilizing school curriculum time, and the conclusions based on the results of the study are as follows. First, for the development of future educational programs using edutech, a content preference survey was conducted and significant responses were confirmed from 27 teachers and 216 students, excluding missing values. In the future education implementation, UCC (video shooting, editing, etc.) and work activities (3D pen, 3D printer, etc.) were selected based on the need for separate edtech devices. Second, in order to develop a future education program using edutech, the future education class module was set in 4 stages based on previous research. First of all, in Make a foundation, theories by subject are developed, and in Open an activity, future education experience activities using key edutech are developed. In Organize evaluation, individual self-evaluation was conducted, and based on this, customized in-depth supplementary activities were conducted in Act individually. Third, in order for future education programs using edutech to be organized in the regular curriculum, sufficient connectivity with the curriculum must be secured. The basis for systematic and stable research was prepared by analyzing the curriculum of the 5th grade subject of the study and securing hours in connection with creative experiential activities. The data developed through this process were modified and supplemented based on the content validity test. The fact that the program application and verification steps were not performed is a limitation of this study, but it is expected that this program will expand the possibility of future education practice in the school field.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.666-671
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• 2023

As international environmental regulations on ship emissions are gradually strengthened, interest in electric propulsion and hybrid propulsion ships is increasing, and various solutions are being developed and applied to these ships, especially stabilization of the power system and system efficiency. The direct current distribution system is being applied as a way to increase the power. In addition, verification and testing of safety and performance of marine DC distribution systems is required. As a result of establishing a DC distribution test bed, verifying the performance of the DC distribution (variable speed power generation) system, and analyzing fuel consumption, this study applied a variable speed power generation system that is applied to DC power distribution for ships, and converted the power output from the generator into a rectifier. A system was developed to convert direct current power to connect to the system and monitor and control these devices. Through tests using this DC distribution system, the maximum voltage was 751.5V and the minimum voltage was 731.4V, and the voltage fluctuation rate was 2.7%, confirming that the voltage is stably supplied within 3%, and a variable speed power generation system was installed according to load fluctuations. When applied, it was confirmed through testing that fuel consumption could be reduced by more than 20% depending on the section compared to the existing constant speed power generation system.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.2
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• pp.129-140
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• 2022

Micro and small enterprises are businesses that absorb the most labor in Korea. The position of micro and small enterprises in the national economy has an important and strategic role because micro and small enterprises are quite dominant in the Korea economy. The purpose of this study is to look at the effect of the CEO' business experience, competency(job competency, money competency, digital competency), government support service(government support satisfaction, education support) on the performance. For this study, data was collected from 220 CEO by using questionnaires. The statistics analysis SPSS 24.0 was used, it is a factor analysis, reliability test and multiple regression analysis for hypothesis verification. The research results are as follows. First, as a result of examining the effect of the CEO competency on the performance, it was found that among the competency factors, money competency and digital competency had a significantly positive (+) effect on the performance. Second, as a result of examining the effect of government support service on the performance, government support satisfaction, education support had a positive (+) effect on the performance. Thirdly, in the relationship between CEO' business experience, competency, government support service and performance, the mediating effect of self efficiency was significant money competency→self efficiency→performance, digital competency→self efficiency→performance.

• Information Systems Review
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• v.20 no.4
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• pp.79-96
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• 2018

This study started by focusing on the internalization of the technology appraisal model into the credit rating model to increase the discriminative power of the credit rating model not only for SMEs but also for all companies, reflecting the items related to the financial stability of the enterprises among the technology appraisal items. Therefore, it is aimed to verify whether the technology appraisal model can be applied to identify high-stability SMEs in advance. We classified companies into industries (manufacturing vs. non-manufacturing) and the age of company (initial vs. non-initial), and defined as a high-stability company that has achieved an average debt ratio less than 1/2 of the group for three years. The C5.0 was applied to verify the discriminant power of the model. As a result of the analysis, there is a difference in importance according to the type of industry and the age of company at the sub-item level, but in the mid-item level the R&D capability was a key variable for discriminating high-stability SMEs. In the early stage of establishment, the funding capacity (diversification of funding methods, capital structure and capital cost which taking into account profitability) is an important variable in financial stability. However, we concluded that technology development infrastructure, which enables continuous performance as the age of company increase, becomes an important variable affecting financial stability. The classification accuracy of the model according to the age of company and industry is 71~91%, and it is confirmed that it is possible to identify high-stability SMEs by using technology appraisal items.

• Journal of Astronomy and Space Sciences
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• v.41 no.1
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• pp.43-60
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• 2024

Korea Pathfinder Lunar Orbiter (KPLO) is South Korea's first space exploration mission, developed by the Korea Aerospace Research Institute. It aims to develop technologies for lunar exploration, explore lunar science, and test new technologies. KPLO was launched on August 5, 2022, by a Falcon-9 launch vehicle from cape canaveral space force station (CCSFS) in the United States and placed on a ballistic lunar transfer (BLT) trajectory. A total of four trajectory correction maneuvers were performed during the approximately 4.5-month trans-lunar cruise phase to reach the Moon. Starting with the first lunar orbit insertion (LOI) maneuver on December 16, the spacecraft performed a total of three maneuvers before arriving at the lunar mission orbit, at an altitude of 100 kilometers, on December 27, 2022. After entering lunar orbit, the commissioning phase validated the operation of the mission mode, in which the payload is oriented toward the center of the Moon. After completing about one month of commissioning, normal mission operations began, and each payload successfully performed its planned mission. All of the spacecraft operations that KPLO performs from launch to normal operations were designed through the system operations design process. This includes operations that are automatically initiated post-separation from the launch vehicle, as well as those in lunar transfer orbit and lunar mission orbit. Key operational procedures such as the spacecraft's initial checkout, trajectory correction maneuvers, LOI, and commissioning were developed during the early operation preparation phase. These procedures were executed effectively during both the early and normal operation phases. The successful execution of these operations confirms the robust verification of the system operation.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.365-371
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• 2024

The purpose of this study was to investigate the effect of leisure satisfaction according to calligraphy activities of the elderly on self-efficacy and psychological well-being. In order to conduct this study, the researchers surveyed 306 elderly people aged 65-76 or older from late November to early December 2023 in Anyang City and Xinxiang City, Henan Province, China. In order to verify the research hypothesis, the researchers performed frequency analysis, descriptive statistics analysis, and Pearson correlation analysis using IBM SPSS Statistics 25, and then performed independent sample T-test and one-way analysis of variance (One-Way ANOVA). To verify the hypothesis through the measurement concept, related verification was conducted for Hayes PROCESS macro and Bootstrap. As a result of the study, first, there is a gender difference in leisure satisfaction, leisure satisfaction, self-efficacy, and psychological well-being, and leisure satisfaction and psychological well-being differ significantly according to age. Second, it was found that leisure satisfaction had a positive effect on self-efficacy. Third, it was found that leisure satisfaction had a positive effect on psychological well-being. Fourth, leisure satisfaction was found to have a positive effect on psychological well-being. Therefore, in order to increase the leisure satisfaction and psychological well-being of the elderly, it is necessary to carefully develop a calligraphy activity system to increase self-efficacy.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.2
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• pp.91-111
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• 2024

Most of utility cable tunnels are constructed utilizing shield TBM as part of the underground transmission line project. The TBM chamber is the only space inside the tunnel that encounters rock and soil, and is the place with the highest frequency of accident exposure, such as collapse and collision accidents. Since there is currently no way to measure the disc cutter wear from outside the chamber, frequent inspection by workers is essential. Accordingly, in this study, in order to prevent safety accidents inside the TBM chamber and expect the effect of shortening the construction period by reducing the number of chamber openings, the concept of disk cutter wear measurement technology was established and a prototype was produced. By considering prior technology and determining that magnetic sensors are most suitable for the excavation environment, wear measurement sensor package were developed integrating magnetic sensors, wireless communication modules, power supply, external casing, and monitoring systems. To verify the performance of the prototype in an actual excavation environment, a full-scale tunnelling test was performed using a 3.6 m EPB shield TBM. Based on the full-scale tests, five prototypes were operated normally among eight prototypes. It was analyzed that sensor measurement, wireless communication, and durability performance were secured within a maximum thrust of 3,000 kN and a rotation speed of 1.5 RPM.

• Journal of Nutrition and Health
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• v.57 no.2
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• pp.244-260
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• 2024

Purpose: With the 2021 revision of dietary guidelines in Korean emphasizing environmentally sustainable dietary practices, this study attempted to develop an evaluation tool to comprehensively evaluate the degree of practice and compliance with food and nutrient intake, dietary habits, and dietary culture guidelines based on the revised dietary guidelines. Methods: The candidate evaluation items were collected by reviewing 934 literature reviews on domestic and foreign dietary evaluations. Fifty-nine candidate items were derived by selecting the items corresponding to dietary guidelines. The content validity ratio (CVR) cutoff point evaluation was conducted with 11 experts to delete 11 items that did not meet the CVR standard. Fifty-five pilot survey candidate items were selected through revision and additional process according to expert opinion. Seventy final candidate items were selected by adding 15 questions for validity verification and reference. A pilot survey was conducted online and offline on 332 adults aged 19-64 in Seoul and the metropolitan area, and exploratory factor analysis was used to verify the construct validity of the evaluation items. Through exploratory factor analysis, the Kaiser-Meyer-Olkin, Bartlett's sphericity test, variance explained, and Cronbach's alpha criteria were confirmed in each process. Results: Exploratory factor analyses derived three criteria: food and nutrient intakes (11 items), eating behaviors (9 items), and dietary culture (14 items), consisting of 34 evaluation items. Conclusion: The present scale was validated and can be used for comprehensive evaluations of the dietary guidelines for Korean adults in a simple way.

• Journal of Internet Computing and Services
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• v.25 no.3
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• pp.71-81
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• 2024

In response to the COVID-19 pandemic, the global airport industry is actively introducing 4th Industrial Revolution technology-based systems for quarantine and passenger safety, and test bed construction and prior verification using airport infrastructure and resources are actively being conducted. Analysis of recent cases shows that despite the changing travel patterns of airport users and the diversification of airport service demands, most testbeds construction studies are still focused on suppliers, and task prioritization is also determined by decision makers. There is a tendency to rely on subjective judgment. In order to find practical ways to become a first mover that leads innovation in the aviation industry, this study selected tasks and derived priorities to build testbeds from a service perspective that reflects various customer service needs and changes. Research results using the AHP analysis method resulted in priorities in the order of access transportation and parking services (29.2%), security screening services (23.4%), and departure services (21.8%), and these analysis results were tested in the airport industry. It shows that innovation in testbeds construction is an important factor. In particular, the establishment of smart parking and UAM transportation testbeds not only helps strengthen airports as centers of technological innovation, but also promotes cooperation with companies, research institutes, and governments, and provides an environment for testing and developing new technologies and services. It can be a foundation for what can be done. The results and implications produced through this study can serve as useful guidelines for domestic and foreign airport practitioners to build testbeds and establish strategies.