• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.163-170
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• 2008

According to the rules, a crash cushion is supposed to set up products that is satisfied with the standard of a performance test after performing the car crash test by road safety facilities and management guide. For development of crash cushion, performance should be estimated through the car crash test eventually. However, there is no reasonable design method which considers passenger's safety and only depend on crash test without an alternative plan. Therefore it incurs a loss materially and takes a lot. Therefore, we are asked to create a systematic design of the crash cushion. This study shows that a scientific basis of applying single degree of freedom when it designs the crash cushion after analyzing vehicle crash test data of crash cushion and also represents design of crash cushion through single degree of freedom response spectrum using calculated by crash test data on crash cushion.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.593-600
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• 2006

Joint opening of jointed concrete pavement is caused by change in temperature and humidity of adjoined slab. The magnitude of joint opening influences on the load-transfer-efficiency and the behavior of sealant. If temperature or humidity decreases, joint opening increases. Generally maximum joint opening of a given joint is predicted by using AASHTO equation. While different magnitudes of joint opening at the individual joints have been observed in a given pavement section, AASHTO equation is limited to predict average joint opening in a given pavement section. Therefore the AASHTO equation may underestimate maximum joint for the half of joint in a given pavement section. Joints showing larger opening than the designed may experience early joint sealant failure, early faulting. Also unexpected spalling may be followed due to invasion of fine aggregate into the joints after sealant pop-off. In this study, the variation of the joint opening in a given pavement section was investigated based on the LTPP SMP data. Factors affecting on the variation are explored. Finally a probabilistic joint opening model is developed. This model can account for the reliability of the magnitude of joint opening so that the designer can select the ratio of underestimated joint opening.

• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.557-570
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• 2023

The purpose of this study is to develop a digital-based non-face-to-face instructional design model for national public servants. For this purpose, we reviewed the direction of non-face-to-face instructional design based on previous research, and interviewed a total of 10 instructors and learners with experience in non-face-to-face education to identify the success factors of non-face-to-face instructional design for government employees. In addition, to ensure the validity of the instructional design model, a Delphi survey was conducted with experts in instructional design and educational management. As a result, the digital-based instructional design model for national public servants reflects the importance of learning objectives and content design to enhance learning motivation and improve educational effectiveness, and includes detailed implementation plans to support specific and clear performance activities for instructors in non-face-to-face education situations. The instructional design model developed through this study can be expanded as a standard for improving the quality of education in public human resource development, and can be used as a teaching and learning guide according to learner types and characteristics.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.2
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• pp.153-165
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• 2022

The COVID-19 Pandemic incident forced all educational and learning activities to move online, so it is no longer an option to use information and communication technology for education and learning. Venture capital has made the largest investment ever in Edu-tech startups. This study investigates the factors influencing the intention to use digital technology in education, taking into account the Unified Theory of Acceptance and Use of Technology (UTAUT) along with digital literacy, which has become an essential ability in the digital age. As a result of the structural equation model analysis, we find that performance expectation, effort expectation, and social influence have a positive effect on the intention to use digital technology in education. Moreover, digital literacy has a positive effect on performance expectation, effort expectation, and social impact, but the direct effect on the intention to use digital technology on learning is not significant. Furthermore, to see the moderating effect of age, the results of multi-group analysis present that the differences between 10s and 60s, between 20s and 60s, between 30s and 60s on the path of social influence on the intention to use digital technology in education are significantly reduced. This study academically contributes to expanding the research on the factors affecting the intention to use digital technology in a specific situation of education by considering both digital literacy and Unified Theory of Acceptance and Use of Technology (UTAUT). In addition, it can be used as a practical guide to the factors to be considered for each age when making learning participants more actively use digital technology.

• Health Policy and Management
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• v.34 no.2
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• pp.106-119
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• 2024

Drug shortage is a persistent phenomenon that poses a public health risk worldwide and occurs due to a range of causes. The purpose of this study is to review key policies to prepare for and respond to drug shortages in selected countries, such as the United States, Canada, and some European countries in order to draw implications. This study reviewed the reports and articles derived from search engines and Google Scholar by using keywords such as drug shortage and stock-out. Over the last decade or so, the United States have strengthened requirements on advance notification for disruption and interruption of drug manufacturing, established the Inter-agency Drug Shortages Task Force to promote the communication and coordination of responses, and expedited drug regulatory processes. Similarly, Canada established the Multi-Stakeholder Steering Committee on drug shortages by involving representatives from central and local governments and private sectors. Canada also adopted a tiered approach to the communication of drug shortages based on the assessment of the severity of the shortage problem and released a detailed information guide on communication. In 2019, the joint task force between the European Medicines Agency and the Heads of Medicines Agencies issued guidelines on drug shortage communication in the European Economic Area. The countries reviewed in this paper focus on communication across different stakeholders for the monitoring of and timely response to drug shortages. The efforts to protect public health from the negative impact of the drug shortage crisis would require multi-sectorial and multi-governmental coordination and development of guidelines.

• Journal of Korean Dental Hygiene Science
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• v.1 no.1
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• pp.47-55
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• 2018

The purpose of this study was to examine the influence of oral health education experience on needs for oral health education in children and adolescents in elementary and secondary schools. A self-administered survey was conducted on the students in elementary, middle and high schools located in the city of Mokpo, South Jeolla Province, from October 1 to 31, 2018. The data that were collected from 327 students were analyzed by SPSS 21.0. Statistical data on frequency, percentage, mean and standard deviation were obtained, and t-test, one-way ANOVA, correlation analysis and logistic regression analysis were carried out. The findings of the study were as follows: First, the subjects got 2.25 on a three-point scale in self-rated oral health status. This score was above average, which indicated that the students thought they were in good oral health. As for problems with oral health, dental caries was given the highest score of 2.48 on a five-point scale, followed by oral malodor with 2.35. Second, the students who experienced oral health education accounted for 69.1 percent, and the students who felt the need for this education represented 82.6 percent. As for educational content desired, the biggest group of 57.8 percent hoped to learn about how to prevent and manage dental caries, and the second largest group of 17 percent wanted to learn about how to take care of oral health during orthodontic treatment. Third, as a result of investigating the state of oral health education by the grade of school, the elementary school students had more oral health education experience than the middle and high school students, and the middle school students placed the most importance on the necessity of oral health education. The differences were statistically significant. Fourth, as a result of analyzing the correlation between oral health education experience and the necessity of oral health education, the students who had more oral health education experience asked more for this education, which implies that there was a statistically significant positive correlation. The findings of the study ascertained that oral health education should be provided for students in childhood and adolescence to boost the level of their oral health knowledge and change their oral health attitude in a positive manner. If oral health practice programs that connect schools, local communities and families with one another are developed to guide the oral health behaviors of teenagers in the right direction, it will make a contribution to the promotion of oral health.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.6
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• pp.11-26
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• 2023

This study aimed to empirically analyze the effect of Korean companies' FDI(Foreign Direct Investment) on their financial performances, particularly divided into profitability, stability, growth and activity, while comparing distinct financial performances between SMEs(small and medium-sized enterprises) and large enterprises whose corporate attributes are different from each other. As research subjects, this study selected FDI Korean companies from the directory of oversea-expanded companies of KOTRA(Korea Trade-Investment Promotion Agency) and used financial data from a total of 409 companies(136 SMEs and 273 large enterprises) with complete financial data for the first five years after the initial investment out of all the financial data from 1990 to 2021. The analysis results can be summarized as follows; In the profitability sector, FDI had positive effects on ROA(Return on Assets) and ROS(Return on Sales) of SMEs, while having negative effects on those of large enterprises to the contrary. In the stability sector, FDI had no statistical significance for SMEs, while having significantly negative effect on LEV(Debt to Equity Ratio) of large enterprises. In the growth sector, FDI had significantly negative effect on AGR(Asset Growth) of SMEs, but showed no significant results for large enterprises. In the activity sector, FDI showed no statistical significance for SMEs, while having positive effects on ATR(Asset Turnover Ratio) and FATA(Fixed Asset Turnover Ratio) of large enterprises. In conclusion, it was found that when having made FDI, SMEs and large enterprises showed different financial performances from each other in terms of profitability, stability, growth and activity.

• Journal of Music and Human Behavior
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• v.21 no.1
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• pp.49-68
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• 2024

This study aims to acoustically analyze Korean language characteristics and convert these findings into musical elements, providing foundational data for evidence-based music-language rehabilitation. We collected voice data from thirty men and thirty women aged 19-25, each providing six-syllable prosodic units composed of two accentual phrases, including both declarative and interrogative sentences. Analyzing this data with Praat, we extracted syllabic acoustic properties and conducted statistical analyses based on acoustic properties, sentence type, gender, and particle presence. Significant differences were found in syllable frequency and duration based on accentual phrases and prosodic units (p < .001), with interrogative showing higher frequencies and declaratives longer durations (p < .001). Female frequencies were significantly higher than males' (p < .001), with longer durations observed (p < .001). Particle syllables also showed significantly stronger intensities (p < .001). Finally, we presented melodies converted from these acoustic properties into musical scores based on pitch, duration, and accent. The insights from this analysis of six-syllable Korean sentences will guide further research on developing a system for melodizing large-scale Korean speech data, expected to be crucial in music-based language rehabilitation.

• Journal of Digital Convergence
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• v.22 no.1
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• pp.1-14
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• 2024

In order to improve the effectiveness of carbon neutrality in Jeju Special Self-Governing Province, this study identifies the current state of social environmental education through literature research, excluding school environmental education being implemented in elementary, middle, and high schools in the province, and identifies shortcomings or problems. The purpose is to establish a plan to systematically and integratedly operate social environmental education, and the derived plan can be used as a guide to change environmental awareness and induce eco-friendly behavior to improve the effectiveness of carbon neutrality. As a result of the study, Jeju Special Self-Governing Province established a consultative body with environmental education institutions, organizations and expert groups operating dispersed throughout the province through the substantial operation and support of the environmental education center currently being entrusted, to identify the current status and develop content necessary for establishing environmental education policies, establishing a platform to enable information sharing, role division, regular communication, empathy, and policy feedback, and on-site environmental education centered on the field to stimulate emotions and personalize environmental problems so that environmental problems can be properly recognized. Emphasizing the necessity.

• Korean Chemical Engineering Research
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• v.62 no.3
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• pp.214-224
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• 2024

Valves play an essential role in a chemical plant such as regulating fluid flow and pressure. Therefore, optimal selection of the valve size and type is essential task. Valve size and type have been selected based on theoretical formulas about calculating valve sizing coefficient (Cv). However, this approach has limitations such as requiring expert knowledge and consuming substantial time and costs. Herein, this study developed a model for predicting valve sizes and types using machine learning. We developed models using four algorithms: ANN, Random Forest, XGBoost, and Catboost and model performances were evaluated using NRMSE & R² score for size prediction and F1 score for type prediction. Additionally, a case study was conducted to explore the impact of phases on valve selection, using four datasets: total fluids, liquids, gases, and steam. As a result of the study, for valve size prediction, total fluid, liquid, and gas dataset demonstrated the best performance with Catboost (Based on R², total: 0.99216, liquid: 0.98602, gas: 0.99300. Based on NRMSE, total: 0.04072, liquid: 0.04886, gas: 0.03619) and steam dataset showed the best performance with RandomForest (R²: 0.99028, NRMSE: 0.03493). For valve type prediction, Catboost outperformed all datasets with the highest F1 scores (total: 0.95766, liquids: 0.96264, gases: 0.95770, steam: 1.0000). In Engineering Procurement Construction industry, the proposed fluid-specific machine learning-based model is expected to guide the selection of suitable valves based on given process conditions and facilitate faster decision-making.