• KIPS Transactions on Computer and Communication Systems
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• v.8 no.8
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• pp.191-200
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• 2019

In an Ad-hoc network, a method of time synchronizing all the nodes in a network centering on one reference node can be used. A representative algorithm based on a reference node is Flooding Time Synchronization Protocol (FTSP). In the process of sending and receiving messages, predictable and unpredictable delays occur, which should be removed because it hinders accurate time synchronization. In multi-hop communications, hop delays occur when a packet traverses a number of hops. These hop delays significantly degrade the synchronization performance among nodes. Therefore, we need to find a method to reduce these hop delays and increase synchronization performance. In the FTSP scheme, hop delays can be greatly increased depending on the position of a reference node. In addition, in FTSP, a node with the smallest node ID is elected as a reference node, hence, the position of a reference node is actually arbitrarily determined. In this paper, we propose an optimal reference node election algorithm to reduce hop delays, and compare the performance of the proposed scheme with FTSP using the network simulator OPNET. In addition, we verify that the proposed scheme has an improved synchronization performance, which is robust to topology changes.

• Korean Journal of Heritage: History & Science
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• v.48 no.3
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• pp.204-219
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• 2015

International society, including the United Nations, has recently been making efforts to further promote a rapprochement of cultures in relation to alleviating military and political conflicts and other social clashes. In line with these efforts at the international level, there has been a growing interest on Central Asia and, in particular, on the Silk Road, which functioned as a trade route among ancient civilizations in the region and is also seen as a route that promoted cultural dialogue and exchanges. Given the amount of cross cultural dialogue and exchange, it is no surprise that intangible cultural heritage has historically been abundant and easily found in the region. However, this heritage was placed in considerable risk because heritage transmission critically weakened for seventy years under Soviet rule. Fortunately, since independence, there has been increasing interest in restoring community identity and reviving intangible heritage. Nevertheless, in spite of this interest, a lack of policies and cultural support in each country has made heritage safeguarding difficult. In this paper, I analyze the various phenomena that took place after the concept and international trends on ICH were introduced and speak about the experiences and outcomes obtained from collaborative network projects by ICHCAP and the Central Asian countries over the last six year. In addition, I would like take this opportunity to discuss how we can understand and develop collaboration in the intangible heritage field in Central Asia in a long-term perspective.

• Therapeutic Science for Rehabilitation
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• v.8 no.3
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• pp.31-41
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• 2019

Objective: This study was conducted to comprehensively analyze domestic and international literature on the oral sensorimotor intervention approaches and evaluation/non-instrumental assessment methods for children with cerebral palsy with feeding disorders. Methods: One hundred and seventy-six papers published from January 2009 to December 2018 were screened. Forty-seven papers were selected based on the abstract and title, and five papers were selected through a secondary search. Results: The PEDro scale of the selected papers was high with an average of 7 points, and the therapeutic intervention period was found to be between 2 and 6 months, providing therapeutic interventions once to 5 times a week, at least 15 minutes to 1 hour a day. The treatment approach was used with impairment-based intervention and adaptive-based intervention, and the assessment method was divided into clinical evaluation and non-instrumental assessments. Conclusion: Through this systematic review, we found that there are a variety of oral sensorimotor interventions for children with cerebral palsy with feeding disorders. This study provides support for planning oral sensorimotor intervention programs for occupational therapy in clinical practice for children with cerebral palsy.

• Journal of Science Education
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• v.45 no.1
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• pp.55-68
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• 2021

The modern society is rapidly changing, and accordingly, the required teacher image is changing as well. Middle school students are immature, when they undergo major changes both physically and mentally, and teachers have a great influence. How students perceive the teacher determines the relationship between teachers and students. Therefore, it is necessary to analyze what kind of teacher image middle school students want. The purpose of this study is to analyze the image of a science teacher who prefers and avoids each class situation perceived by middle school students. To this end, 502 middle school students were divided into five classes: class type, class material presentation method, subject instruction method, subject content explanation method, and class atmosphere, and the image of science teacher who prefers and avoids is described in an open format. Concepts presented by middle school students were analyzed through semantic network analysis (SNA). The conclusions of this study are as follows: first, in order to make middle school students interested in science, an inquiry-centered experiment class should be conducted. Second, the change of class by science teacher can change it into preferred science class. Third, student-centered classes should be conducted according to the level so that students can understand. Finally, science teachers continue to strive through communication between science teachers and students, and students and students, and look forward to changes in science classes through this.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.3
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• pp.226-237
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• 2020

The purpose of the research is to analyze research trends related to climate change education by network analysis based on keywords extracted from the research title. For this purpose, 62 papers were selected from Korean Citation Index(KCI) journals published from 2011 to 2020 using such keywords as "climate change" and "climate change education" in the Research Information Sharing Service. The analysis procedure consisted of selection of analysis papers, keyword extraction and purification, and keyword network analysis and visualization. Textom, Ucinet 6.0, and NetDraw were used to analyze the frequency, degree centrality, and betweenness centrality. The results of the research showed that, first, Early 'Energy and Climate Change Education' had the highest frequency of papers examining climate change education. Second, the keywords/phrases that appeared most frequently in research on climate change education were "program" "energy," "analysis," "elementary school," "elementary school," "elementary school students," "development," and "impact." Third, the analysis of the centrality of betweenness centrality showed that the index of 'program', 'primary students' and 'primary schools' were the highest, and the largest group was 'development and effect of teaching and learning programs'. Based on these results, it was concluded that future research on climate change education needs to be examined in further detail and expanded into more specific areas.

• Journal of The Geomorphological Association of Korea
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• v.20 no.4
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• pp.15-28
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• 2013

This paper was made on the basis of geotourism to explain morphological characteristics of Patagonia and Atacama region in the Andes through 10-day fieldwork. The Patagonian landscape was focused on the Torres del Paine National Park, Chile and the Los Glacier National Park, Argentina; on the other hand, the Atacama morphological landscape was investigated around the San Pedro de Atacama. Many geomorphological features such as uplift, semiarid and glacier landscapes can be found in Patagonia, so it is strongly recommended to have an opportunity to enjoy these landforms by geotourism. Massive intrusive rock bodies of granite can be shown in those two National Parks declared a Biosphere Reserve by UNESCO. And, the Atacama Desert located on the forearc depression in the Andes, Chile has also many geomorphological destinations of arid and volcanic landforms; badland, pediplain, pediment, salt lake and geyser. Especially, huge pediplain is one of the greatest view points in the Atacama Desert. Patagonia and Atacama are the best geographical tourism sites to know diverse tectonic landforms made by the conflict between South American and Pacific plates.

• The Journal of Korean Philosophical History
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• no.59
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• pp.371-393
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• 2018

Jeong Yak-yong attempted to establish a new philosophical system through the criticism on Neo-Confucianism. The most important area among the ideas of Dasan is on the ethical thoughts. He has a tremendous interest in the ethical education as well as ethical thought. During his exile, he gathered children around and educated them by editing "Jegyeong(弟經)". Dasan regarded "Sohak(小學)" to have some problems in educating children. Thus, he reconstructed the contents of "Sohak" and edited "Jegyeong". "Jegyeong" is more concise than Sohak and is a textbook focusing on children which is mainly composed of practical etiquette in the everyday life. It contains etiquettes to parents, teachers and adults, etiquettes on food in the everyday life and etiquettes between men and women. Although the contents does not exceed the scope of Sohak, he selected reasonable contents and composed with practical contents. Thus, it is practical. Dasan also attempted to make a novel interpretation on Saseo (四書), i.e., Noneo, Maengja, Daehak and Jungyong. His new interpretation on Saseo can be considered as ethical textbooks in a broad sense. Dasan considered the key ethical principle of Saseo (四書) to be Seo (恕). Accordingly, he thought it is very important to understand and practice ethical principle of Seo (恕). Dasan studied and annotated "Simgyeong(心經)" and "Sohak(小學)" for self moral discipline. And, he thought it is utmost important to understand and accept the existence of Sangje (上帝) in order to keep moral mind. He believed it to be important to have Gyesingonggu (戒愼恐懼), which is to aware and respect the existence of Sangje (god) for self discipline and Sindok (愼獨) to be cautious about things that only he was aware of. He thought that if people are aware of Sangje (上帝) and make dialog with Sangje, the will of Sangje could be expressed into Dosim (道心). In the ethical education, it can be said that, ultimately, the awareness on the absolute being is the most important point to Dasan.

• Journal of The Korean Association For Science Education
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• v.41 no.2
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• pp.155-169
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• 2021

This study aims at exploring the features of science teaching orientation (STO) and its relationships with other PCK (pedagogical content knowledge) components. To do this, based on the definition of STO by Friedrichsen, Driel, & Abell(2011) and PCK model by Magnusson, Krajcik, & Borko(1999), we observed one experienced elementary teacher's science lessons for 21 lesson hours (10 hours of 'Motion of Objects' and 11 hours of 'Light and Lens') and carried out qualitative analyses of the data obtained from lessons observation, teacher interviews, and CoRe (content representation) responses. We analyzed the teacher's three aspects of STO (i.e. beliefs about the goals and purpose of science teaching, beliefs about the nature of science, and beliefs about science teaching and learning) which can converge into an overall STO of 'inquiry'. And these aspects of STO appear to interact differently with four PCK components (i.e. curriculum knowledge, learner knowledge, instructional knowledge, and assessment knowledge) depending on the topic of the lesson. It is hoped that this in-depth understanding of the features of STO and its relationship with other PCK components would provide useful information on how to monitor and improve STO and PCK of elementary teachers.

• Ecology and Resilient Infrastructure
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• v.8 no.1
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• pp.1-8
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• 2021

A surface image velocimeter (SIV) measures the velocity of a particle group by calculating the intensity distribution of the particle group in two consecutive images of the water surface using a cross-correlation method. Therefore, to increase the accuracy of the flow velocity calculated by a SIV, it is important to accurately calculate the displacement of the particle group in the images. In other words, the change in the physical distance of the particle group in the two images to be analyzed must be accurately calculated. In the image of an actual river taken using a camera, camera lens distortion inevitably occurs, which affects the displacement calculation in the image. In this study, we analyzed the effect of camera lens distortion on the displacement calculation using a dense and uniformly spaced grid board. The results showed that the camera lens distortion gradually increased in the radial direction from the center of the image. The displacement calculation error reached 8.10% at the outer edge of the image and was within 5% at the center of the image. In the future, camera lens distortion correction can be applied to improve the accuracy of river surface flow rate measurements.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.456-468
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• 2020

This exploratory study, related to the introduction of Western-style family doctors, was conducted based on a comparative survey of medical care satisfaction in foreign residents of the U.S. and Canada based on a consumer-centered perspective. As a result of statistical analysis based on 493 collections of empirical data from 2016 to 2018, the main conclusions of this study are as follows. First, there was no evidence that satisfaction with US and Canadian family doctors was higher than the satisfaction with Korean primary care physicians. Second, satisfaction with Korean primary care physicians was high with regard to treatment, promptness, etc., and there was no evidence that foreign family doctor systems were better in terms of sufficient counseling and explanation. Third, overseas Koreans in the United States showed less satisfaction with their family doctors than Koreans in Canada. Fourth, overseas Koreans preferred to visit a hospital directly, without a referral from the family doctor. In conclusion, there is insufficient evidence showing that satisfaction with family doctors in the U.S. and Canada is higher than satisfaction with primary care doctors in Korea. Therefore, a more in-depth, additional analysis on the Western-style family doctor is needed before introducing such a system in Korea.