• Journal of Internet of Things and Convergence
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• v.10 no.1
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• pp.1-6
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• 2024

In order to increase the use of electric vehicles (EVs) and minimize grid strain, microgrid using renewable energy must take an important role. Microgrid may use fossil fuels such as small diesel power, but in many cases, they can be supplied with energy from renewable energy, which is an eco-friendly energy source. However, renewable energy such as solar and wind power have variable output characteristics. Therefore, in order to meet the charging and discharging energy demands of electric vehicles and at the same time supply load power stably, it is necessary to review the configuration of electric vehicle charging infrastructure that utilizes diesel power or electric vehicle-to-grid (V2G) as a parallel energy source in the microgrid. Against this background, this study modelized a microgrid that can stably supply power to loads using solar power, wind power, diesel power, and V2G. The proposed microgrid uses solar power and wind power generation as the primary supply energy source to respond to power demand, and determines the operation type of the load's electric vehicles and the rotation speed of the load synchronous machine to provide stable power from diesel power for insufficient generations. In order to verify the system performance of the proposed model, we studied the stable operation plan of the microgrid by simulating it with MATLAB /Simulink.

• Journal of Industrial Convergence
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• v.21 no.10
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• pp.141-150
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• 2023

The purpose of this study is to empirically analyze the impact of role stress (role conflict, role ambiguity, and role overload) on career commitment and turnover intention in small and medium-sized hospital workers in Busan. The subjects of the study were 418 nursing and administrative workers engaged in hospitals and general hospitals in Busan. Frequency analysis, correlation analysis, and regression analysis were conducted for empirical analysis. The results of the study are as follows. First, significant differences in some research variables were identified according to gender, age, educational background, marital status, and working years. Depending on the job type, there were significant differences in all variables such as role conflict, role ambiguity, role overload, career commitment, and turnover intention. Second, role stress was found to have a significant negative effect on career commitment and a significant positive effect on turnover intention. Among the role stress, it was confirmed that the role overload had the strongest influence on career commitment and turnover intention. This study is meaningful in that it analyzed the influence of role stress, including workers in all occupations, including nursing jobs, and empirically revealed the meaning of role stress as an explanatory variable of career commitment and turnover intention.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.1-8
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• 2023

If there is a defect in the wheel bearing, which is a major part of the car, it can cause problems such as traffic accidents. In order to solve this problem, big data is collected and monitoring is conducted to provide early information on the presence or absence of wheel bearing failure and type of failure through predictive diagnosis and management technology. System development is needed. In this paper, to implement such an intelligent wheel hub bearing maintenance system, we develop an embedded system equipped with sensors for monitoring reliability and soundness and algorithms for predictive diagnosis. The algorithm used acquires vibration signals from acceleration sensors installed in wheel bearings and can predict and diagnose failures through big data technology through signal processing techniques, fault frequency analysis, and health characteristic parameter definition. The implemented algorithm applies a stable signal extraction algorithm that can minimize vibration frequency components and maximize vibration components occurring in wheel bearings. In noise removal using a filter, an artificial intelligence-based soundness extraction algorithm is applied, and FFT is applied. The fault frequency was analyzed and the fault was diagnosed by extracting fault characteristic factors. The performance target of this system was over 12,800 ODR, and the target was met through test results.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.5
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• pp.1-18
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• 2023

The Ecosystem Conservation Levy (formerly known as the Ecosystem Conservation Cooperation Fund) system has been in place for 20 years, and it can be said that it has now entered the settlement stage. Based on an analysis of publicly available project implementation data from 2014 to 2020, we found that: 1) As the number of return projects increases, the targets of restoration technologies are also strengthening, and it is necessary to frame a series of processes from application, creation, and monitoring for some detailed projects to improve the effectiveness and efficiency of utilizing the levy. 2) Most of the implemented projects are applied as micro-ecosystem creation, but there are many cases where the contents of the project can be seen as other project categories. This shows that the purpose of the return project needs to be approached more clearly and suggests that institutional complementation is needed from the project application stage. 3) The detailed technologies applied tend to be gradually expanding, but most of them are technologies that are not differentiated from general development projects. It is urgent to secure a more technical identity, such as a range and list of utilized technologies suitable for the characteristics and purposes of return projects. 4) It is necessary to establish a relevant evaluation system or framework to utilize the monitoring results of restoration projects. 5) There have been few cases of application of single restoration technologies since the beginning, but the content and scope of the complexity tend to expand in recent years. Even if the objectives are not comprehensive and diverse, it can be seen that many parts of the projects are oriented toward convergence, so it is necessary to conduct separate research on this. 6) As for the direction of improvement of the return project, it is possible to consider expanding the restoration and conservation focus to partially accommodate the complexity of the natural environment and human ecology. It seems that the expansion of restoration technologies that consider the role and function of humans in the natural environment should be explored.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.783-790
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• 2023

The term edutech has recently been attracting attention as the convergence of education and technology is emphasized. Schools are also exploring teaching methods using edutech. The purpose of this study is to analyze the satisfaction of 210 radiology students after using Quizn Platform and the difference in satisfaction with Quizn Platform according to general characteristics. The research results are as follows. First, as a result of the satisfaction analysis according to class type, the following order was practical class, theory + practice class, and theory class. Second, the desired teaching methods among theory classes according to general characteristics were core classes (quiz solving), lecture-style classes, discussions, and discussion classes. Third, 'Quizn was used appropriately in class.' had the highest score at 4.27±0.60, and 'I am very interested in this subject.' had the lowest score at 3.98±0.74. Additionally, there was no significant difference in response to the teaching method (p>0.05). Fourth, 'Applying Quizn to class was interesting and fun' showed the highest score at 4.24±0.94, and 'Institutional support must be provided to continue using Quizn at 3.49±0.96. Additionally, there was no significant difference in satisfaction with classes according to gender and age (p>0.05). As a limitation of this study, although we investigated the satisfaction of students using Quizn, we were unable to investigate the satisfaction of instructors who interact with students. In the future, research that considers instructor satisfaction in classes using edutech should be conducted. Universities must provide institutional support and continuous interest until edutech is selected and utilized.

• Industry Promotion Research
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• v.8 no.4
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• pp.113-122
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• 2023

This study is a research study aimed at finding out the relationship between lifestyle and life satisfaction of single youth households and the relationship between the mediating role of interpersonal relationships and the effect of parents' social and economic status regulation in the relationship between lifestyle and life satisfaction. To this end, this study conducted a self-written survey of single-person youth households across the country through an online survey institution, regardless of gender, and used a total of 501 copies out of 520 subjects for final results analysis. The data were analyzed using the SPSS 25.0 and AMOS 25.0 programs, and the applied statistical techniques included correlation analysis, confirmatory factor analysis, structural equation model analysis, multi-group analysis, and bootstrap. As a result of the study, there was a significant positive (+) correlation between lifestyle, life satisfaction, and interpersonal relationships of single youth households, and interpersonal relationships were found to have a mediating effect in the relationship between lifestyle and life satisfaction. It was found to have a significant positive (+) effect on income and income satisfaction, but the moderating effect of education, economic activity, housing ownership type, and class consciousness was not significant. Based on the results of these studies, it was intended to provide basic data for developing various community programs and institutional arrangements for single youth households.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.5
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• pp.169-175
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• 2023

This paper analyzes museum-related big data using museums and gamification using social media big data, identifies and compares the perceptions of visitors mentioned in social media, and presents ways to use gamification. Based on the collected data, this paper aims to provide data by comparing and analyzing the perception of visitors to the museum and visitors to the museum using gamification. This paper investigates the perception of visitors through social media analysis using TEXTOM, a social media analysis tool, to identify differences in perception. As a result of the analysis, it was found that compared to museums that were previously viewed in the form of exhibitions, they felt fun and interest in visiting museums using geikipication. In addition, based on the analysis results of keywords and related keywords, the perception, motivation, and type of viewing of the museum of the National Museum of Korea and the Independence Hall of Korea were confirmed. In addition, it can be seen that the sense of achievement of visitors who visited the museum using gamification is higher than that of the existing museum. It is believed that by developing and activating game-related content in future museum visits, many visitors will be able to increase their interest in the museum and feel fun and interested. The results of the study are believed to be meaningful as basic data to grasp the overall perception of visitors to the museum, and based on this, it is expected that visitors will be able to see and experience the museum in various ways.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.5
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• pp.785-796
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• 2023

In this study, a methodology for real-time classification and prediction of defects that may appear in PVDF(Polyvinylidene fluoride) sensors, which are widely used for structural integrity monitoring, is proposed. The types of sensor defects appearing according to the sensor attachment environment were classified, and an impact test using an impact hammer was performed to obtain an output signal according to the defect type. In order to cleary identify the difference between the output signal according to the defect types, the time domain statistical features were extracted and a data set was constructed. Among the machine learning based classification algorithms, the learning of the acquired data set and the result were analyzed to select the most suitable algorithm for detecting sensor defect types, and among them, it was confirmed that the highest optimization was performed to show SVM(Support Vector Machine). As a result, sensor defect types were classified with an accuracy of 92.5%, which was up to 13.95% higher than other classification algorithms. It is believed that the sensor defect prediction technique proposed in this study can be used as a base technology to secure the reliability of not only PVDF sensors but also various sensors for real time structural health monitoring.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.897-907
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• 2023

The purpose of this study is to find out the development direction of adult learners' blended learning class as a study on the class satisfaction of adult college students according to the blended learning class participation type. To this end, a survey was conducted targeting adult learners at two schools that are carrying out the LiFE project (lifelong education system support project). The analyzed research results are as follows. First, in the case of adult learners, the proportion of participating in liberal arts + major classes as a blended learning subject was 77.8%, and home was the highest with 69.8% as a place to participate in online classes. Second, satisfaction with the blended learning teacher/instructor teaching method was generally satisfied with 95.2% of average or higher. Third, 96.8% of the students answered 'yes' or higher regarding the level of satisfaction with the blended learning method. The above research results show that blended learning is one of the important teaching and learning methods in providing adult-tailored education to adult learners who combine work and study. It can be seen that the blended learning teaching method is an effective teaching method that enables interactive communication between the instructor and the learner rather than the one-way teaching-oriented content delivery class of the traditional classroom.

• Journal of Industrial Convergence
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• v.21 no.12
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• pp.11-23
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• 2023

This study aims to investigate the relationship between service recovery justice, residual emotions, and customer behavior. It empirically verifies that low justice in service recovery affects residual emotions and, in turn, has an impact on customers' negative behaviors. Furthermore, this research distinguishes customer-brand relationship quality into emotional relationship quality and cognitive relationship quality and seeks to validate that the type of relationship quality may influence the extent to which the justice of recovery processes affects residual emotions. Data was collected through surveys, and hypotheses were tested using structural equation modeling. The research findings indicate that among the dimensions of service recovery justice, procedural justice and interactional justice significantly influence residual emotions. Moreover, residual emotions have a significant impact on both the intention to revisit and the intention to engage in negative word-of-mouth. In addition, the impact of distributive justice and procedural justice on residual emotions was found to be higher for cognitive relationship quality than emotional relationship quality, and the impact of interactional justice on residual emotions was found to be higher for emotional relationship quality than cognitive relationship quality.