• Journal of Educational Research in Mathematics
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• v.26 no.1
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• pp.79-101
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• 2016

Understanding the equal sign is of great significance to the development of algebraic thinking. Given this importance, this study investigated in what ways a total of 695 students from second to sixth graders understand the equal sign. The results showed that students were successful in solving standard problems whereas they were poor at items demanding high relational thinking. It was noticeable that some of the students were based on computational thinking rather than relational understanding of the equal sign. The students had a difficulty both in understanding the structure of equations and in solving equations in non-standard problem contexts. They also had incomplete understanding of the equal sign. This paper is expected to explore the understanding of the equal sign by elementary school students in multiple problem contexts and to provide implications of how to promote students' understanding of the equal sign.

• Journal of Educational Research in Mathematics
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• v.27 no.3
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• pp.329-350
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• 2017

This paper examined vocabulary used in elementary mathematics textbooks and workbooks for the grade band of 5~6. This study focused on the adequacy of vocabulary using 9-degree of semantic difficulty. The results of this study showed that most vocabulary in the textbooks and workbooks was adequate for the target grades. In some cases, however, vocabulary that was supposed to be difficult for the fifth and sixth graders was employed in a way that the meaning of such vocabulary was difficult for students to infer in the given context. The most frequent vocabularies in the main activities of the mathematics textbooks included 'method', 'investigate', 'number', 'communicate', and 'represent'. Based on these results, this study provides 5~6 grade textbook writers with implications on what to further consider in dealing with vocabulary in instructional materials.

• The Journal of Korean Society for School & Community Health Education
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• v.15 no.2
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• pp.103-113
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• 2014

Objectives: The purpose of this study was to clarify the relationship between perceived oral health and oral health status, oral health symptoms in elementary school students. Methods: Oral examination and oral hygiene survey were performed on 446 students in 5th grade from 4 elementary schools in Wonju, Gangwon province. Oral examination assessed decayed teeth, filled teeth, missing teeth from decay. Then, oral hygiene status was evaluated by O'Leary index and self-reported questionnaires were surveyed. We analysed the collected data using SPSS program ver. 20.0, significant difference level was p<0.05. Results: 38.4% of the subjects rated their oral health as poor, 61.6% as good, female students was worried about their appearances than male students. Their decayed teeth was 1.01, missed teeth was 0.01, filled teeth was 1.75, O'Leary index was 64.49, oral hygiene status of them was poor. Perceived oral health was associated to decayed teeth, DMFT, oral health symptoms except tooth fracture and pain of mucosa (p<0.05). However, there is no correlation between perceived oral health and oral hygiene status (p>0.05) Conclusion: Self-rated oral health status of the elementary school students was related to decayed teeth and oral health symptoms, but it was not related to oral hygiene status. Therefore it was needed to improve the oral hygiene status in elementary students by devise effective way to motivate them.

• Journal of Korean society of Dental Hygiene
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• v.7 no.1
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• pp.61-72
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• 2007

The purposes of this study were to investigate the oral health status of the disabled children attending special schools in Seoul and Gyeonggi area, which were to collect baseline data for set up a oral health center in special schools. The study group comprised 915 disabled children aged 12~15 year. They were examined clinically and surveyed on 4 oral health related characteristics according to the type and level of disabilities The results may be summarized as follows: 1. DMFT index was the highest in children with crippled disorder. The plaque control was more required to the children with mental retardation or developmental disorder other than another types of disabilities. 2. About one third of the children with mental retardation or developmental disorder had their teeth brushed at least 3 times daily without any help. Over the half of the children with crippled disorder had their teeth brushed 2 times daily, 33.3% were independent and 38.9% totally dependent on help from others. 3. The more level of disabilities was higher, the more frequency of tooth brushing was lower and degree of dependance of the tooth brushing was higher. 4. There was tendency to visit to dental office more frequently for relief of dental symptoms in children with crippled disorder 5. The inability to call for help from others was the major barrier to dental care for the disabled.

• Journal of Educational Research in Mathematics
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• v.23 no.1
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• pp.1-16
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• 2013

The primary purpose of this study is to survey multiplicative thinking levels and its characteristics of third graders in elementary school and to analyze how to use it when they solve the proportional problems. As results, the transition thinking ranked the highest among the four kinds of thinking levels when the $3^{rd}$ graders solved the multiplication problems. It means that the largest numbers of students still can not distinguish the additive and multiplicative situations completely and remain in the transition thinking, which thinks both additively and multiplicatively. In addition, the performance of solving proportional problems was distinguished from the levels of thinking. Through this study, we can give some implications of the importance of multiplicative thinking and instructional methods related to multiplication.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.413-415
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• 2019

In this paper, we develop IoT-HiAS(IoT-Human Interactive Advertising Service) for sharing economy. The HiAS device shooting the front of the device via a webcam and recognizes the person in real time through the SSD model using MobileNet. If the number of persons above the set threshold is recognized by counting the recognized person, the advertisement is reproduced on the idle resource through the beam projector. At the same time as the advertisement is reproduced, the captured image of the advertisement start time in the front of the device and the number of recognized persons are sends the IoT server of an oneM2M-compliant HiAS server using the IoT client. When the advertisement is finish, the webcam is shooting the front of the device and the image is sends the IoT server. We implemented the IoT-based human interactive advertising service by transmitting the received data to the advertiser and the advertising producers through the SNS(Social Network Service) agent of the HiAS server.

• The Korea Journal of Herbology
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• v.37 no.5
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• pp.17-26
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• 2022

Objective : The aim of the present study is to examine hepatic lipid-lowering and anti-inflammatory effects of silymarin combined with Jakyakgamcho-tang on non-alcoholic fatty liver disease in a high fat diet-induced obese mice model. Methods : C57BL/6 mice were divided into four dietary groups: (1) Normal, (2) Control (60% high-fat diet), (3) Control + silymarin 50 mg/kg/day (Silymarin), (4) Control + Silymarin 50 mg/kg/day + Jakyakgamcho-tang 100 mg/kg/day (SPG). After 12 weeks administration, mice were sacrificed and lipids and inflammation-related biomarkers were analyzed liver and plasma. Results : Silymarin and SPG treatments significantly lowered body and liver weights compared to the Control. Serumlipids (triglyceride (TG), total cholesterol) and pro-inflammatory cytokines (tumor necrosis factor alpha, interleukin 1𝛽, and IL-6) concentrations were significantly lowered in the Silymarin and SPG groups than the Control group. Silymarin and SPG treatments suppressed hepatic TG level and hepatic lipid droplets compared to the Control. Theses two treatments significantly increased hepatic kinase B1 and AMP-activated protein kinase protein levels, and significantly decreased hepatic key lipogenic enzymes (acetyl-CoA carboxylase, fatty acid synthase and stearyl coenzyme A desaturase 1) protein levels than the Control. SPG also significantly increased hepatic fatty acid oxidation-related protein (peroxisome proliferator-activated receptor alpha and uncoupling protein 2) levels than the Control. Conclusions: Silymarin and SPG suppressed hepatic lipid accumulation by regulating hepatic protein expression, and lowered blood pro-inflammatory cytokines concentrations though the synergic effect of silymarin and Jakyakgamchotang was not clear.

• Education of Primary School Mathematics
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• v.25 no.4
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• pp.433-457
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• 2022

An effective teacher community helps the participating teachers improve their instructional quality. This study reports a teacher community consisting of 15 elementary school teachers and one teacher educator. This paper analyzed 15 mathematics lessons in which the teachers implemented the five practices for orchestrating productive mathematics discussions by Smith and Stein (2018) based on the grade-specific discussions as well as the whole community's discussions. The results of this study showed that the overall levels of each practice either increased gradually or maintained at the highest Level 4, as mathematics lessons had been implemented. Specifically, the following practices were quite successful: setting goals for a lesson, selecting an appropriate task, anticipating student responses, and selecting student solutions. However, both sequencing and connecting student solutions were implemented at various levels. Monitoring student work tended to remain at Level 2 which included incorrect implementation of the practice. This paper closes with implications related to the skillful implementation of the five practices through a teacher community.

• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.101-106
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• 2017

Based on the previous reports that majority of teachers have negative perceptions on food additives, a teacher training program called 'Let's teach food additives correctly' was developed and applied to improve teachers' unbalanced perception on food additives and let them teach students with sound scientific background. The 15-hours training program consisted of understanding of food safety and food additives, education materials on food additives, development of teaching-learning plan, meeting with professionals from Ministry of Food and Drug Safety (MFDS), visiting MFDS labs, application to school class, and evaluation. A total of 63 teachers participated in the training through 2 sessions conducted in August 2016. As a result, teachers showed high satisfaction rates (4.2~4.5 in 5.0-Likert scale) and 91.5% answered the training helpful for the school class. Although their initial intention to participate the training was to know the details of negative intake effects of food additives, their such perception was totally changed in addition, they suggested a continuous training for teachers and immediate correction of incorrect information in school textbooks. Also, post-training education for 1,172 students by these teachers appeared to improve the understanding of and the native perceptions on food additives significantly (p < 0.001). Above results showed that the training program could solve the problem of transmitting unbalanced information on food additives to students by training teachers, and such channel could be used to facilitate food-related risk communication.

• The Korea Journal of Herbology
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• v.36 no.6
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• pp.39-46
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• 2021

Objectives : AMP-activated protein kinase (AMPK) is a key metabolic regulator that reduces lipogenesis. AMPK is mainly activated via phosphorylation of liver kinase B (LKB) 1 under energy stress. Here, we highlighted the anti-obesity effect and underlying mechanism of Coix lacryma-jobi var. mayuen Stapf sprout water extract (CSW) sprout extract in connection with the LKB1/AMPK signaling pathway. Methods : C57BL/6 mice (20~25 g) fed HFD to induce obesity and at the same time administered CSW 100 mg/kg (CSWL; (CSWL; CSW low concentration) or CSW 200 mg/kg (CSWH; CSW high concentration) or Garcinia extract (Garcinia) 200 mg/kg orally for 6 weeks. Body weight and food intake were measured at the same time each day. After 6 weeks of CSW administration, liver tissue and serum were obtained through an autopsy. After the end of the experiment, biochemical analysis (triglycerides (TG), total cholesterol (TC), HDL-cholesterol, and LDL-cholesterol) was performed on the serum. And then, protein levels related to TG and TC synthesis were measured through western blot analysis in liver tissue. Results : As a result, serum TG, TC, and LDL-cholesterol levels were significantly increased in the control group and significantly decreased in the CSW administration group. On the other hand, the HDL-cholesterol level was increased in the CSW-administered group. And as a result of Western blot analysis, CSW significantly increased the phosphorylation of LKB1 & AMPK, and remarkably decreased the expression of factors related to TG and TC synthesis. Conclusions : Our findings suggest that CSW influences the TG and TC synthesis to positively affect HFD-induced obesity in C57BL/6 mice.