• Journal of the Korean School Mathematics Society
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• v.21 no.4
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• pp.445-467
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• 2018

In this study, we analyzed the contents of pi and the area of a circle presented in Korean, Japanese, Singapore, and American mathematics textbooks, and drew implications for the teaching of pi and the area of a circle in school mathematics. We developed a textbook analysis framework by theoretical discussions on the concept of the pi based on the various properties of pi and the area of a circle based on the central ideas of measurement and the previous researches on pi and the area of a circle in elementary mathematics. We drew five suggestions for improving the teaching of pi and three suggestions for improving the teaching of the area of a circle in Korean elementary schools.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.332-338
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• 2021

Civil aviation cybersecurity challenges are global in nature and must be addressed using global best practices and the combined efforts of all stakeholders. This requires the development of comprehensive international strategies and detailed plans for their implementation, with appropriate resources. It is important to build such strategies on a common methodology that can be applied to civil aviation and other interrelated critical infrastructure sectors. The goal of the study was to determine the methodological basis for developing an international civil aviation cybersecurity strategy, taking into account existing experience in strategic planning at the level of international specialized organizations. The research was conducted using general scientific and theoretical research methods: observation, description, formalization, analysis, synthesis, generalization, explanation As a result of the study, it was established the specifics of the approach to formulating strategic goals in civil aviation cybersecurity programs in the documents of intergovernmental and international non-governmental organizations in the aviation sphere, generally based on a comprehensive vision of cybersecurity management. A comparative analysis of strategic priorities, objectives, and planned activities for their implementation revealed common characteristics based on a single methodological sense of cybersecurity as a symbiosis of five components: human capacity, processes, technologies, communications, and its regulatory support. It was found that additional branching and detailing of priority areas in the strategic documents of international civil aviation organizations (by the example of Cybersecurity Strategy and Cybersecurity Action Plan) does not always contribute to compliance with a unified methodological framework. It is argued that to develop an international civil aviation cybersecurity strategy, it is advisable to use the methodological basis of the Cyber Security Index.

• Informatization Policy
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• v.28 no.2
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• pp.98-113
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• 2021

This study presents implications of the Global Data Law & Policy by comparing national data strategies, data regulations and policies, and governance in South Korea, the United States, the United Kingdom, and the European Union. According to the result of the comparative analysis, the biggest difference is in data governance, in other words, the management and coordination of policies at the pan-government level and data ethics. Therefore, this study proposes the establishment of a presidential special committee on data policy or the creation of a 'National Digital Innovation Office' at the Presidential Secretariat as a national CDO for the governance of data policies. Furthermore, this paper suggests a) to enact 'the Framework Act on the Development of Data Industry' that can regulate data practices in the private sector, b) to institutionalize the data-centric security and data protection, c) to settle the public ethics and personnel management based on data expertise and professional ethics, including explainability and responsibility, and d) the education and training systems.

• Nutrition Research and Practice
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• v.16 no.2
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• pp.272-283
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• 2022

BACKGROUND/OBJECTIVES: Most child and adolescent food literacy measurement tools focus on nutrition and food safety. However, the importance of aspects related to the food system such as food distribution and food waste and their effects on environmental sustainability is growing. We therefore developed and validated a two-dimensional tool for children (8-12 years old) and adolescents (13-18 years old) that can comprehensively measure food literacy. The association of food literacy with diet quality and self-reported health was assessed. SUBJECTS/METHODS: First, we developed a food literacy conceptual framework that contains food system and literacy dimensions through a literature review, focus group interviews, and expert review. After a face validity study, we conducted the main survey (n = 200) to validate the questionnaire. Construct validity and reliability were assessed using exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and Cronbach's alpha. RESULTS: As a result of the Delphi study, content validity was confirmed for the remaining 30 items after two items were excluded (content validity ratio = 0.86). Eleven items were excluded from the EFA results, while the CFA results indicated appropriate fit indices for the proposed model (comparative fit index = 0.904, root mean square error of approximation = 0.068). The final food literacy questionnaire consisted of 19 questions and comprised 5 factors: production, distribution, selection, preparation and cooking, and intake. Food literacy was positively associated with diet quality, as assessed by the Nutrition Quotient score, in both children and adolescents and with self-reported health in adolescents.

• Communications of Mathematical Education
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• v.36 no.4
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• pp.589-610
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• 2022

This study aimed to derive pedagogical implications by comparing and analyzing how the concept of pi is taught in 10 different elementary mathematics textbooks, which are scheduled to be applied from 2023. We developed a textbook analysis framework by previous studies on the concept of pi and the teaching of pi, and analyzed in terms of three instructional elements (i.e. inferring conceptsof pi, understanding properties of pi, and applying relationships). We derived the need to emphasize various contexts for estimation of pi, presentation of problem situations that provide motivation to actually measure diameters and circumferences, providing an opportunity to explore the properties of measurement, and an experience the flexibility of selecting an approximate value of pi. Based on the above conclusions and pedagogical implications through the research results., we suggested ways to teach the concept of pi in elementary mathematics and improvement points for developing textbooks focusing on the context of introduction of pi and the use of technological tools.

• Journal of Korean Society for Quality Management
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• v.50 no.3
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• pp.593-615
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• 2022

Purpose: The purpose of this study was to explore and examine the factors influencing customer satisfaction and subscription intention in order to propose useful implication regarding subscription economy model. Methods: This study adopts the extended Unified Theory of Acceptance and Use of Technology model (UTAUT2) as the theoretical framework. On the basis of literature review, this study suggested 9 related hypothesis. To examine the hypothesis proposed, the study designed surveys with 32 questions and 456 answers were collected for the analysis. The study adopted a structural equation model and path analysis, using AMOS and SPSS programs. Results: The results of this study are as follow: All hypothesis except performance expectancy and effort expectancy have significant influence on customer satisfaction. Performance expectancy and effort expectancy have no significant influence on customer satisfaction and facilitate condition is significant but negatively associated with customer satisfaction. Conclusion: Result of this study is expected to suggest data regarding subscription economy and customer satisfaction for business with subscription model. In detail the result implies that highly sophisticated curation system would create more customer satisfaction and subscription intention rather than how a subscription-based platform is easily used. Moreover, curation system of subsription-based music platform should function with high accuracy on recommendation in a creative visual form in order to gain comparative advantage while most platforms have built own curation service.

• Journal of Advanced Navigation Technology
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• v.28 no.1
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• pp.68-76
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• 2024

With the recent rapid growth of the domestic and international unmanned aerial vehicle (UAV) market and the increasing importance of UAV operations in urban centers, such as UAMs, the safety management and regulatory framework for human life and property damage caused by UAV failures has been emphasized. In this study, we conducted a comparative analysis of risk-cost models that evaluate the risk of an operating area for safe UAM flight path planning, and identified the main limitations of each model to derive considerations for future model development. By providing a basic model for improving the safety of UAM operations, this study is expected to make an important contribution to technical improvements and policy decisions in the field of UAM flight path planning.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.4
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• pp.431-443
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• 2007

Statement of problem: Injuries along with discomfort may result on the oral mucosa when non-rigid material is used as the major connector in construction of RPD, since nonrigid major connectors transmit unstable forces throughout the appliance. Titanium which recently draws attention as a substitute of Co-Cr had a difficulty in fabricating due to high melting temperature but the development of casting technique makes it possible to apply to the clinical case. Purpose: The purpose of this study was to investigate the rigidity and the castability of titanium upper major connector by design and make a comparison with Co-Cr major connectors which are widely used in clinical cases now. Material and methods: Casting was done using CP-Ti(Grage 2) (Kobe still Co., Japan) for the experimental groups, and 4 various designs namely palatal strap, U-shaped bar, A-P strap, and complete palatal plate were casted and 5 of each designs were included in each group. For the experimental group, Universal testing machine (Model 4502; Instron, Canton, Mass) was used to apply vertical torsional force vertically to the horizontal plane of major connector. In the second experiment, Vertical compressive force was applied to the horizontal plane of major connector. As a comparative group, Co-Cr major connector was equally manufactured and underwent the same experimental procedures Strain rate was measured after constant loading for one minute duration, and statistical analysis was done with SPSS ver.10.0 for WIN(SPSS. Inc. USA). From the one-way ANOVA and variance analysis (P=0.05), Scheffe's multiple comparison test implemented. Results: 1. Least amount of strain was observed with complete palatal plate followed by A-P bar, palatal bar, and the U-shaped bar having most amount of strain. 2. In all designs of titanium major connector, less strain rate was observed under compressive loading than under torsional loading showing more resistance to lateral force. 3. For titanium major connector, less strain rate was observed when the force is applied to the first premolar area rather than to the second molar area indicating more strength with shorter length of lever. 4. In Comparison of Co-Cr major connector with titanium major connector, palatal strap and U-shaped bar designs showed higher strength under torsional force that is statically significant, and under compressive force, no significant difference was observed expert for U-shaped bar. 5. In titanium major connector, complete palatal plate showed lowest success rate in casting when compared with the Co-Cr major connector. Conclusion: Above results prove that when using titanium for major connector, only with designs capable of generating rigidity can the major connector have almost equal amount of rigidity as Co-Cr major connector and show lower success rate in casting when compared with the Co-Cr major connector.

• Journal of The Korean Association For Science Education
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• v.40 no.6
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• pp.621-630
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• 2020

This study compared and analyzed the contents of secondary earth science curriculum in Mongolia and South Korea to check the contents of earth science education in both countries and to prepare basic data necessary for future earth science curriculum revisions. The research questions of this study are: first, to understand the changes and current operating conditions of earth science curriculum in both countries, to compare and analyze with other foreign cases, and second, to compare and analyze the contents of earth science and curriculum in both countries. The TIMSS evaluation framework is used to compare and analyze the earth science-related contents included in the science curriculum of middle schools. For analyzing the contents of high school, the contents of NGSS in the United States and the earth science curriculum contents of high schools in South Korea were mixed and the analysis frameworks were created and validated by experts. As a result of the study, countries that follow the Russian-style education system did not organize and operate earth science as an independent science subject, and deal with earth science-related content in the natural geography area of the geography subject. The earth science contents covered in middle school science curriculum in both countries, 18 of the 27 content elements of the TIMSS content analysis framework were matched in Mongolia and 20 in South Korea. In high school curriculum, the contents of earth science in Mongolia were described more briefly and not covered than in South Korea. In particular, the Mongolian geography curriculum dealt with many environmental issues. The emphasis on the operation method of the earth science curriculum in Mongolia and the contents related to the environment can be used as a reference when developing an interdisciplinary integrated curriculum of science and social studies in South Korea.

• Industry Promotion Research
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• v.5 no.3
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• pp.61-71
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• 2020

The purpose of this paper is to reaffirm the logical framework of the saju analysis method by recreating the saju model of old-law to study and organize the theories of frame in old-law Myeongri, and then by organizing and comparing the logic structure of the saju analysis method of new-law and old-law. Some believe that Myeongri Theory first appeared in the world in the Warring States Period when they were active with Gwigokja and Naknokja as origin, while others believe that it was origin that "Okjokyeong" was written by Kwak-Bak of Eastern Jin after a while. Since then, Myeongri Theory, which had been organized by Won-Cheongang and Yi-Heojung, has undergone a major transformation since reaching the Song Dynasty Seo-Japyeong. Based on this point, the Myeongri Theory of the previous generation is called the Old-law, and the subsequent theory is called the New-law. The changes in the logic structure of the old-law and the new-law leave a big difference and disconnect between those. But comparative studies have confirmed that the philosophy and logic structure due to natural laws that have not changed much such as the symbolic system of nature called Yinyang & five elements and Cheongan-jiji, the idea of a heavenly response projected in the Three Wonders of heaven, earth and human, and the concept of generation and time in the position of year-month-day-time.