• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.188-195
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• 2024

Recently, the use of recycled aggregates from construction waste has been introduced as a solution for environmental problems and aggregate shortage. In spite of the various methods to promote recycling of recycled aggregate, the use of recycled aggregate as the structural aggregate has been limited because the quality of recycled aggregate(especially recycled fine aggregate) has been considered lower than that of natural aggregate. In this work, recycled fine aggregate was immersed for an hour in acrylic resin solutions of various concentrations to improve its quality, the appropriate immersion concentration was selected by measuring the absorption capacity and skeletal density of the recycled fine aggregate, and mortar specimens were prepared to evaluate the mechanical performance in order to propose a applicable treatment process to promote the use of recycled fine aggregate. According to the experimental results, as the acrylic resin concentration increased, the absorption capacity and skeletal density of the recycled fine aggregate decreased. The absorption capacity was lowest at acrylic resin concentrations around 6 to 8 %. However, among mortar specimens made of recycled fine aggregate immersed in acrylic resin solution, the compressive strength was the highest at 4 % acrylic resin concentration, suggesting that the use of higher concentration acrylic resin solution can actually lower the compressive strength of mortar.

• 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.

• Smart Media Journal
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• v.12 no.11
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• pp.48-56
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• 2023

The technology of Three-dimensional human posture estimation is used in sports, motion recognition, and special effects of video media. Among various methods for this, multi-view 3D human pose estimation is essential for precise estimation even in complex real-world environments. But Existing models for multi-view 3D human posture estimation have the disadvantage of high order of time complexity as they use 3D feature maps. This paper proposes a method to extend an existing monocular viewpoint multi-frame model based on Transformer with lower time complexity to 3D human posture estimation for multi-viewpoints. To expand to multi-viewpoints our proposed method first generates an 8-dimensional joint coordinate that connects 2-dimensional joint coordinates for 17 joints at 4-vieiwpoints acquired using the 2-dimensional human posture detector, CPN(Cascaded Pyramid Network). This paper then converts them into 17×32 data with patch embedding, and enters the data into a transformer model, finally. Consequently, the MLP(Multi-Layer Perceptron) block that outputs the 3D-human posture simultaneously updates the 3D human posture estimation for 4-viewpoints at every iteration. Compared to Zheng[5]'s method the number of model parameters of the proposed method was 48.9%, MPJPE(Mean Per Joint Position Error) was reduced by 20.6 mm (43.8%) and the average learning time per epoch was more than 20 times faster.

• Journal of the Korean Society of Radiology
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• v.83 no.5
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• pp.1032-1045
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• 2022

Peripheral arterial disease (PAD) is common in elderly patients. Lower-extremity CT angiography (LE-CTA) can be useful for detecting PAD and planning its treatment. PAD can also be accurately evaluated on reconstructed monoenergetic images (MEIs) from low kiloelectron volt (keV) to high keV images using dual-energy CT. Low keV images generally provide higher contrast than high keV images but also feature more severe image noise. The noise-reduced virtual MEI reconstruction algorithm, called the Mono+ technique, was recently introduced to overcome such image noise. Therefore, this pictorial review aimed to present the imaging findings of PAD on LE-CTA and compare low and high keV images with those subjected to the Mono+ technique. We found that, in many cases, the overall and segmental image qualities were better and metal artifacts and venous contamination were decreased in the high keV images.

• Journal of Wetlands Research
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• v.26 no.1
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• pp.10-20
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• 2024

The conservation and restoration of wetlands are essential tasks for the sustainable development of human society and the environment, providing vital benefits such as biodiversity maintenance, natural disaster mitigation, and climate change alleviation. This study aims to analyze the strategic interactions and interests among various stakeholders using game theory and to provide significant grounds for policy decisions related to wetland restoration and development. In this study, hypothetical scenarios were set up for three types of cities: large, medium, and small. Stakeholders such as governments, development companies, environmental groups, and local residents were identified. Strategic options for each stakeholder were developed, and a payoff matrix was established through discussions among wetland ecology experts. Subsequently, non-cooperative game theory was applied to analyze Nash equilibria and Pareto efficiency. In large cities, strategies of 'Wetland Conservation' and 'Eco-Friendly Development' were found beneficial for all stakeholders. In medium cities, various strategies were identified, while in small cities, 'Eco-Friendly Development' emerged as the optimal solution for all parties involved. The Pareto efficiency analysis revealed how the optimal solutions for wetland management could vary across different city types. The study highlighted the importance of wetland conservation, eco-friendly development, and wetland restoration projects for each city type. Accordingly, policymakers should establish regulations and incentives that harmonize environmental protection and urban development and consider programs that promote community participation. Understanding the roles and strategies of stakeholders and the advantages and disadvantages of each strategy is crucial for making more effective policy decisions.

• Journal of Industrial Convergence
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• v.22 no.5
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• pp.127-136
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• 2024

This study was conducted to examine the self-efficacy and rejection sensitivity of nursing college students and their college life adjustment, as well as to identify the impact of self-efficacy and rejection sensitivity on college life adjustment. An online survey via URL was conducted on 154 enrolled students from nursing colleges nationwide. The collected data were analyzed using SPSS/WIN 23.0 statistical software for descriptive statistics, independent t-test, ANOVA, Pearson's correlation coefficients, and hierarchical regression analysis. The results of the study showed that the self-efficacy of the subjects was 3.80±0.63 points, rejection sensitivity was 2.67±0.83 points, and college life adjustment was 3.58±0.54 points. The factor influencing the college life adjustment among nursing college students was self-efficacy (β=.42, p<.001), while rejection sensitivity showed a significant negative correlation with adaptation to university life (r=-0.24, p=.003), but it was not a significant influencing factor. Therefore, it is necessary to develop and utilize various teaching methods and programs for psychological and social support to enhance self-efficacy in order to improve the adjustment of nursing college students to college life.

• Journal of Industrial Convergence
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• v.22 no.5
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• pp.89-96
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• 2024

This is a descriptive research study to confirm the mediating effect of empathy in the relationship between communication skills and interpersonal relationship of MZ generation nursing students. The subjects of this study were 129 nursing students born in 1981 to 2006, corresponding to the MZ generation, and the data collection period was from May 20 to July 30, 2023. The collected data were analyzed using the SPSS 25.0 program, and the mediating effect of empathy was tested by Baron and Kenny's three-step mediating effect verification procedure, and Sobel test was conducted to test the statistical significance of the mediating effect. As a result of the analysis, communication skills (β=.45, p<.001) and empathy (β=.18, p=.008) had a significant effect on interpersonal relationship. These variables were found to have 48.4% explanatory power for interpersonal relationship. Empathy had a partial mediating effect (z=2.39, p=.016) in the relationship between communication skills and interpersonal relationship. Based on the results of this study, it is necessary to understand the characteristics of the MZ generation familiar with the non-face-to-face culture that will be in charge of future nursing and to develop effective programs to improve their interpersonal relationship.

• Smart Media Journal
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• v.13 no.1
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• pp.36-44
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• 2024

Metaverse is attracting attention as the development of virtual environment technology and the emergence of untact culture due to the COVID-19 pandemic. In this study, by analyzing users' reviews on the "Zepeto" application, which has recently attracted attention as a metaverse service, we tried to confirm changes in the requirements for the metaverse after the COVID-19 pandemic. To this end, 109,662 reviews of "Zepeto" applications written on the Google Play Store from September 2018 to March 2023 were collected, topics were extracted using LDA topic modeling technique, and topics were analyzed using the Causal Impact technique to examine how topics changed before and after based on "March 11, 2020" when the COVID-19 pandemic was declared. As a result of the analysis, five topics were extracted: application functional problems (topic1), security problems (topic 2), complaints about cryptocurrency (Zem) in the application (topic 3), application performance (topic 4), and personal information-related problems (topic 5). Among them, it was confirmed that security problems (topic 2) were most affected by the COVID-19 pandemic.

• Journal of Industrial Convergence
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• v.22 no.3
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• pp.51-65
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• 2024

This study aims to understand positive changes in balance and gait function and difficulties in the instructor's guidance process through repetitive basic motor skill-based physical activities targeting people with cerebellar ataxia. For this purpose, five adults with cerebellar ataxia were selected as research subjects, and their three instructors participated as research participants. To collect quantitative data, the average and standard deviation were examined through pre-and post-evaluation of the research participants' physical activity classes for 16 weeks. The mean and standard deviation of the collected data were calculated using the Shapiro-Wilk test in the SAS 9.1 statistical program (p<.05). As a qualitative data collection method, the cultural description method of developmental research(DSR) proposed by Spradley(1980) was adopted, and the collected data were analyzed inductively according to the analysis method of Mertens(1990). Through this, 31 concepts, 10 subcategories, and 4 categories were discovered. As a result, the difficulties experienced by the research participants included insufficient guidance environment, dissatisfaction of consumers, difficulty in guidance, and non-cooperation of colleagues. Based on these research results, it was found that institutional, legal, and policy support should be provided not only to public institutions but also to private physical activity institutions that can use vouchers in order to maintain the balance of adults with cerebellar ataxia as well as to guide their physical activities.

• Geophysics and Geophysical Exploration
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• v.27 no.1
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• pp.23-36
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• 2024

In this study, we analyze the structure of the Korea-Japan Joint Development Zone (JDZ) using gravity, magnetic, and seismic data. Gravity and magnetic data analysis confirmed that the Jeju Basin exhibits low anomalies compared to adjacent areas. We applied the total gradient to the Bouguer anomaly to identify basin boundaries, and computed the analytic signal from the total magnetic anomaly data to enhance the edges of the magnetic anomalies. The Taiwan-Sinzi Belt, exhibits high magnetic anomalies and crosses the center of the JDZ in the northeast-southwest direction; we presume that intrusive rocks are sporadic in the JDZ. The 3D inversion results of the gravity and magnetic data show a strong correlation between magnetic susceptibility and density (i.e. a low-density zone in the Jeju Basin and the Ho Basin, and a high magnetic susceptibility distribution in the Taiwan-Sinzi Belt). Comparison of the density and seismic profiles of the Jeju Basin shows that high densities are associated with sill, horst, and basement highs, whereas low densities are associated with basement low and grabens. These results suggest that interpretations based on seismic, gravity and magnetic data can effectively reveal the subsurface structure of the JDZ.