• 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.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.4
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• pp.103-116
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• 2023

The purpose of this study is to investigate the relationship between vertical leadership and shared leadership, organizational trust and innovation resistance. For this purpose, a regression analysis was conducted based on data from 286 questionnaires completed by employees working in IT companies. As a result of the analysis, both shared leadership and vertical leadership showed a negative relationship with innovation resistance. For organizational trust, it was confirmed that there was a mediating effect in the relationship with innovation resistance. Shared leadership seems to form a stronger negative relationship with innovation resistance than vertical leadership, it was found that shared leadership is more effective in lowering innovation resistance. Therefore, if the strengths of vertical leadership and shared leadership are applied complementary to each other on the basis of organizational trust in promoting innovation, it will be a good way to overcome innovation resistance, which is a barrier to innovation success. To overcome innovation resistance, especially in IT startups, we propose the complementary application of vertical leadership and shared leadership based on organizational trust.

• Health Policy and Management
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• v.34 no.1
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• pp.26-37
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• 2024

Background: The purpose of this study was to compare and analyze the differences in charges and length of stay per case between spine specialty hospitals and non-specialty hospitals, and to identify the factors that influenced them. Methods: This study used claims data from the Health Insurance Review and Assessment Service, including inpatient visits from January 2021 to December 2022. The healthcare facility status data was used to identify the characteristics of study hospitals. Multilevel analysis was conducted to identify factors associated with the charges and Poisson regression analysis was conducted to analyze the length of stay between spine specialty hospitals and non-specialty hospitals. There were 32,015 cases of spine specialty hospitals and 17,555 cases of non-specialty hospitals. Results: For four of five common spinal surgeries, specialty hospitals shaped longer length of stay than those of non-specialty hospitals. Multilevel and Poisson regression analysis revealed that regardless of the type of surgery, higher age and higher Charlson comorbidity index scores were significantly associated with an increase in both the charges per case and length of stay (p<0.05). However, when hospitals were located in metropolitan areas, there was a significant decrease (p<0.05). Conclusion: This study found that specialty hospital had higher inpatient charges and loner length of stay contrary to the previous study results. Further studies will be needed to find which contribute to the differences.

• Journal of Industrial Convergence
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• v.22 no.6
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• pp.107-120
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• 2024

This study aimed to identify factors associated with metabolic abnormalities in non-obese and obese postmenopausal women based on biopsychosocial model. Secondary data analysis was conducted using data from 5,335 postmenopausal women who participated in the Korean National Health and Nutrition Examination Survey (2015-2021). According to logistic analysis with applying a complex simple analysis in SPSS 26.0, biomedical (increased age; a family history of hypertension, type 2 diabetes, dyslipidemia, and cardiovascular diseases) and biosocial factors (low educational level) were associated with 1-2 metabolic abnormalities and metabolic syndrome, regardless of adiposity. Additionally, low familial socioeconomic status and prolonged sedentary behaviors were the biosocial and psychosocial factors associated with metabolic syndrome regardless of adiposity. Finally, insufficient physical activity was associated with metabolic syndrome in obese postmenopausal women. Based on these results, tailored strategies should be developed considering the significant factors associated with metabolic abnormalities and adiposity in postmenopausal women.

• Information Systems Review
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• v.25 no.1
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• pp.75-91
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• 2023

Thanks to information technologies, sharing economy services offer a new way of consumption. Carsharing appeared as a novel type of service that transformed the conventional way of personal transportation, from owning a vehicle to using an on-demand service. Allowing users to use a vehicle without owning a car, carsharing provides various social benefits such as the reduction of resource allocation inefficiencies and the alleviation of transportation problems. To strengthen such positive aspects of carsharing service, it is essential to understand an individual's service usage pattern and reveal factors that affect users' reuse behavior. This study investigates the factors that have an influence on carsharing reuse of users applying RFMC (Recency, Frequency, Monetary, and Clumpiness) model, the popular model for understanding the reuse likelihood of customers. Using data from a leading carsharing service provider in South Korea, we empirically analyze the effect of RFMC on carsharing reuse behavior. The findings show that recency and monetary values are negatively related to reuse while frequency is positively related to carsharing service reuse. Moreover, the impact of recency and monetary value are more salient whereas the impact of frequency is smaller among users with higher clumpiness. Based on these findings, this study elaborates on theoretical and practical implications.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.17-26
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• 2024

The purpose of this study is to explore the direction of the role of lifelong vocational education as a field of lifelong education based on the content analysis of the innovation plan for lifelong vocational education and training in 2018. The conclusion is as follows. First, in terms of policy orientation, the direction of lifelong vocational education is possible to carry out life-integrated lifelong vocational education in terms of lifelong education. Second, in the education and training process, lifelong education can be carried out in specific practical competency areas in terms of lifelong vocational education. Third, in the case of the education and training system, in terms of lifelong vocational education, the philosophy of lifelong education is to establish an education system that spans the entire life. Fourth, in the case of education and training programs, various programs can be operated by type of lifelong education institution in terms of lifelong vocational education. Fifth, in the case of education and training, lifelong education can be distributed evenly across life stages from the perspective of lifelong vocational education. Sixth, in terms of the relationship with the industrial sector, lifelong education can strengthen the connection with industrial demand in terms of lifelong vocational education, and it can also strengthen the connection with government agencies. Seventh, in the case of support for the underprivileged, lifelong education is viewed from the perspective of lifelong vocational education. Free education and customized support for the underprivileged are possible at provincial and provincial lifelong education institutions and city, county, and district lifelong learning centers.

• Korean Journal of Radiology
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• v.21 no.10
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• pp.1165-1177
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• 2020

Objective: To assess the feasibility of applying a deep learning-based denoising technique to coronary CT angiography (CCTA) along with iterative reconstruction for additional noise reduction. Materials and Methods: We retrospectively enrolled 82 consecutive patients (male:female = 60:22; mean age, 67.0 ± 10.8 years) who had undergone both CCTA and invasive coronary artery angiography from March 2017 to June 2018. All included patients underwent CCTA with iterative reconstruction (ADMIRE level 3, Siemens Healthineers). We developed a deep learning based denoising technique (ClariCT.AI, ClariPI), which was based on a modified U-net type convolutional neural net model designed to predict the possible occurrence of low-dose noise in the originals. Denoised images were obtained by subtracting the predicted noise from the originals. Image noise, CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were objectively calculated. The edge rise distance (ERD) was measured as an indicator of image sharpness. Two blinded readers subjectively graded the image quality using a 5-point scale. Diagnostic performance of the CCTA was evaluated based on the presence or absence of significant stenosis (≥ 50% lumen reduction). Results: Objective image qualities (original vs. denoised: image noise, 67.22 ± 25.74 vs. 52.64 ± 27.40; SNR [left main], 21.91 ± 6.38 vs. 30.35 ± 10.46; CNR [left main], 23.24 ± 6.52 vs. 31.93 ± 10.72; all p < 0.001) and subjective image quality (2.45 ± 0.62 vs. 3.65 ± 0.60, p < 0.001) improved significantly in the denoised images. The average ERDs of the denoised images were significantly smaller than those of originals (0.98 ± 0.08 vs. 0.09 ± 0.08, p < 0.001). With regard to diagnostic accuracy, no significant differences were observed among paired comparisons. Conclusion: Application of the deep learning technique along with iterative reconstruction can enhance the noise reduction performance with a significant improvement in objective and subjective image qualities of CCTA images.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.281-287
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• 2024

In general, design education related to transportation has been recognized as a department specialized in transportation design or as an area of detailed transportation majors within industrial design majors. However, as technological, social, and environmental factors change, the concept of mobility and the ecosystem related to the mobility industry are diversifying, and accordingly, the category of mobility-related design is expanding further. Based on this background, this study is not a mobility design major, but it aims to find implications by analyzing the trend and type of topic selection related to the mobility ecosystem among the last five years of graduation design topics conducted in the design engineering major. As a result of the study, of a total of 131 graduation design works conducted over the past five years, about 30 works were highly related to mobility, and their types were very diverse. In conclusion, it was confirmed that the change and expansion of the mobility ecosystem expanding from products to services and systems were also reflected in the selection of graduation works in that various topics approached from user-centered and user experience were proposed and made into works.