• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.4
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• pp.281-290
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• 2015

The aim of this study was to evaluate shear bond strength (SBS) of bulk-fill resin composites (RCs) to dentin and their micro-leakage. One high-viscosity bulk-fill RC and 2 low-viscosity bulk-fill RCs were compared with 1 conventional RC. 7thgenerationbondingagentswereused. In order to evaluate SBS values, 40 permanent molars were selected and divided into 4 groups. The bulk-fill RCs were applied in 4 mm thickness, whereas the conventional RC was applied in 2 mm thickness. In order to evaluate micro-leakage, class I cavities ($5{\times}2{\times}4mm$) were prepared in 32 permanent molars. The teeth were divided into 4 groups and restored with resin composites in an increment of 4 mm for the bulk-fill RC and in 2 horizontal increments of 2 mm for the conventional RC. The mean SBS value of conventional RC showed no statistically significant difference when compared with those of low-viscosity bulk-fill RCs. However, the mean SBS value of high-viscosity bulk-fill RC was significantly lower than that of conventional RC (p < 0.05). There were no statistically significant differences in micro-leakage between the 4 groups. For SBS and micro-leakage, the use of low-viscosity bulk-fill RCs might help clinicians simplify the procedure.

• Journal of the Korea Institute of Building Construction
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• v.17 no.4
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• pp.305-312
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• 2017

To evaluate the reliability of fly ash quality supplied to ready-mixed concrete plant using mass cylinder and hydrometer, in this research, the correlationship between the fly ash properties provided from certification and density measurement with suspension was evaluated. As a result, the reliability of the certification, except fineness and loss on ignition, all properties had a discord. Additionally, in the case of density, fineness, and L.O.I, the relation with the density measured using hydrometer showed high correlation, especially fineness was strongly related with the density measured using hydrometer. Furthermore, according to the comparative analysis with previous research, the fly ash used in this research was similar measurement with raw powder without any refining process, it is considered that the constant error of blaine test or using raw ash sample as a fly ash. In current standard regarding fly ash, the fineness range of class 2 can be changed from $3,000-4,500cm^2/g$ to $3,500-4,500cm^2/g$ for improved quality of fly ash in fineness aspect.

• Journal of Science Education
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• v.36 no.2
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• pp.394-407
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• 2012

This study analyzed the result of the National Assessment of Educational Achievement (NAEA) in a Grade 9 Science class. The study first found that the ratio of below basic achievement was 8.1 percent. This means that a large number of middle school students have not reached basic scientific literacy. Second, the ratio of male students in the below basic level was 10.4 percent, which was double the ratio of female students at 5.5 percent. Third, according to the analysis of achievement by gender, female students outperformed male students. In addition, the female students' standard deviation was smaller than that of the male students, and their scaled scores were distributed nearer the average than that of the male students. Furthermore, analysis of achievement by content domains indicated that females outperformed in all content domains including motion and energy, materials, life, and earth sciences. Showing a similar tendency in the behavior domains, females outperformed males in all behavior domains except the understanding domain. Last, for achievement by living area, students living in the middle and small cities showed the highest scaled score, 196.81. Whereas the average scaled score of the students living in the big cities was 196.15; that of the students living in rural areas was 194.86. With respect to the standard deviation, big cities had the largest, 33.73. That of middle and small cities was 33.70, and of rural areas was 32.92. Although students in cities showed higher achievement in science compared to students in rural areas, they had a bigger gap in academic achievement.

• Journal of Science Education
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• v.36 no.2
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• pp.354-368
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• 2012

The purpose of this study was to explore the direction of application and quality management plan of science curriculum of elementary and middle school according to the 2009 revised curriculum. In order to do this, nationwide survey was administered. The subject was 126 elementary school teachers and 88 middle school science teachers. It was founded that teachers had negative opinion on the introduction of the grade cluster system. They considered that it was appropriate to link the contents of Science subject with Practical Arts(Technology Home Economics) subject by similar topic. Science classes were implemented without changing the number of class hours in most schools. They recognized the necessity of differentiated instruction in science classes, but they seldom applied the differentiated instruction. And they suggested that the teaching-learning materials, evaluation materials and contents be provided to apply the STEAM. This study designates the following strategic supports for the effective implementation of 2009 revised science curriculum; 1) the science teachers training program to provide useful information for understanding and teaching the 2009 revised science curriculum, 2) the teachers' community in the school, 3) the development and provision of the feasible STEAM plans.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.2
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• pp.109-123
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• 2014

Kaloula borealis is the species of Amphibia which belongs to Kaloula genus and it is the only species inhabiting in Korea. The population size and habitat of Kaloula borealis have been significantly decreased on a national scale due to the diversified developments and the uses of agricultural pesticides. Accordingly, the Ministry of Environment has designated and managed them as the class II of endangered species, in accordance with "Endangered Species Protection and Management Act"; however, a particular study focused on the ecological restoration of Kaloula borealis is desperately needed to prevent their extinction. This study was conducted to propose the HSI (Habit Suitability Index) of Kaloula borealis based on literature survey on ecology and habitats of Kaloula borealis, as well as their HSI. Factors to be investigated in HSI include: space, feed, cover, water(breeding) and threatening factors and the variables of each factor were also proposed. The distance from wetland, grassland, farm, stream and rice paddy, as well as the altitude of spawning pond were proposed as the variables of space, whereas the bed structure of forest and low-rise grassland were proposed as the variables of feeding. The variables of water (breeding) include the area of permanent and temporary wetlands, coverage of emerged pants (ratio of open water), water depth, water temperature, water quality, pH level, etc., whereas the presence of predator, distance from street and pollutants were proposed as the variables of threatening factor. The sub-standards by HSI factor of Kaloula borealis have been drawn from in-depth consultation with experts and based on this, the final HSI of Kaloula borealis was developed.

• School Mathematics
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• v.19 no.1
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• pp.19-41
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• 2017

The purpose of this article was to a) identify how preservice teachers conceive feedbacks and subsequent classroom discourses, and b) compare them with those in reform-oriented mathematics classroom video for mathematics teachers' professional development about classroom discourse. This article analyzes feedback patterns and subsequent classroom discourses in preservice teachers' imaginary classroom scripts (lesson plays) and compares them with those in the reform-oriented classroom video dealing with the same teaching situation. Most of the preservice teachers' feedbacks focused the evaluation of students' responses and transmission of meaning (univocal function), whereas the teacher's feedback in the reform-oriented classroom allowed the whole class to validate or challenge the answers, thereby facilitating students' generation of meaning (dialogic function). The comparison analysis between the univocal discourse in a preservice teacher's lesson play and the dialogical discourse in the reform-oriented classroom video shows that teacher feedback serves as an important indicator for the main function of classroom discourse and the levels of students' cognitive participation, and also as a variable that determines and changes them. This case study suggests that to improve the quality of classroom discourse, preservice and in-service teachers need experience of perceiving the variety of feedback patterns available in specific teaching contexts and exploring ways to balance the univocal and dialogical functioning in their feedback move during the teacher training courses.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.194-202
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• 2017

This study is a methodological study analyzing the results of applying capstone design to nursing education. Among the nursing college students who completed the fundamental nursing subject, the students who agreed to participate in the research were composed of the project team and proceeded as team activities. It was conducted through knowledge - team composition - topic selection / analysis - design / development - simulation - evaluation / feedback process starting from knowledge learned through fundamental nursing class. The research period was from January 1, 2015 to October 30, 2015 for 6 months. BBS (Bed Sore Socks) was developed for the prevention of pressure ulcers, and BBS was applied for seven days to randomly selected patients in the long term care facility. The incidence and pressure ulcer risk scores were assessed. The results of the pilot study showed that the intervention group had an effect on the incidence of pressure ulcer ($x^2=.40$, p = .500) and the pressure ulcer risk score (z = -.45, p = .690), but it was not statistically significant. Capstone design was trailed in the field of nursing education and produced the bed sore socks. In the nursing education, not many capstone design trails appeared yet, this study might be the first trail in the field of nursing, and it could be challenging for expanding of nursing education.

• Radiation Oncology Journal
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• v.36 no.1
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• pp.25-34
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• 2018

Purpose: This study aimed to evaluate the initial outcomes of proton beam therapy (PBT) for hepatocellular carcinoma (HCC) in terms of tumor response and safety. Materials and Methods: HCC patients who were not indicated for standard curative local modalities and who were treated with PBT at Samsung Medical Center from January 2016 to February 2017 were enrolled. Toxicity was scored using the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Tumor response was evaluated using modified Response Evaluation Criteria in Solid Tumors (mRECIST). Results: A total of 101 HCC patients treated with PBT were included. Patients were treated with an equivalent dose of $62-92GyE_{10}$. Liver function status was not significantly affected after PBT. Greater than 80% of patients had Child-Pugh class A and albumin-bilirubin (ALBI) grade 1 up to 3-months after PBT. Of 78 patients followed for three months after PBT, infield complete and partial responses were achieved in 54 (69.2%) and 14 (17.9%) patients, respectively. Conclusion: PBT treatment of HCC patients showed a favorable infield complete response rate of 69.2% with acceptable acute toxicity. An additional follow-up study of these patients will be conducted.

• Journal of Oral Medicine and Pain
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• v.15 no.1
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• pp.27-35
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• 1991

In order to evaluate muscular activity patterns of masticatory muscles and asymmetry patterns of muscular activity according to the levels of occlusal force, twenty-one individuals of age ranged from 23 to 27 years were examined. They were selected according to the following criteria : 1) no symptoms of temporomandibular disorder, 2) complete dentition except third molars, 3) normal or Angle's class I molar relationship and 4) no experience of dental treatment. The electromyographic amplitudes was measured for evaluation of muscular activity and asymmetric patterns of masseter and anterior temporal muscle during unilateral clenching at the levels of 10%, 20%, 40% and 50% of the maximum occlusal force by use of electromyogram and bite force meter. The obtained results were as follows : 1. The muscle activity indices of masticatory muscles of clenching side at the clenching levels of 10%, 20% and 30% of the maximum occlusal force were -19.12, -9.87, -0.49%, so that activity of anterior temporal muscle was dominant than that of masseter muscle. At the levels of 40%, 50% of the maximum occlusal force, muscle activity indices were 4.68%, 6.70%, so that activity of masseter was dominant at all level and as the levels of occlusal force was increased, muscular activity index was tend to decrease. 2. In masseter, asymmetry indices of muscular activity at the levels of 10%, 20% of maximum occlusal force were -10.34 and -1.24%, so that muscular activity of non-clenching side were dominant and at the levels of 30%, 40% and 50% each of maximum occlusal force, muscular activity was dominant on clenching side as 4.68, 7.18 and 10.9%. In anterior temporal muscle, asymmetry indices were 33.38%, 25.46, 2095, 10.23 and 15.45% at the levels of 10%, 20%, 30%, 40% and 50% each of maximum occlusal force, so that activity of clenching 15.45% at the levels of 10%, 20%, 30%, 40% and 50% each of maximum occlusal force, so that activity of clenching side was dominant than that of non-clenching side at all levels, but as the levels of occlusal force was increased, asymmetry indices of muscular activity was tend to decrease. 3. Between both sides, average electromyographic amplitudes of masseter and anterior temporal muscle were correlated, so that as the levels of occlusal force was increased, average electromyographic amplitudes of both side in same muscle were increased proportionally. But asymmetry indices between muscular activities of masseter and anterior temporal muscle were not correlated.

• Journal of The Korean Association For Science Education
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• v.20 no.3
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• pp.384-395
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• 2000

Recently performance assessments have been recommended as an alternative to traditional assessment methods such as multiple-choice written test. Performance assessment is suggested to facilitate students' creativity, participation and learning motivations in science classes. In this study, performance assessment materials were developed for a biology unit of middle school science 1, 'Plants Around Us', and then the assessment materials were applied to assess students' understandings and attitudes related to each topic of the unit. A total of 186 7th grade students at a southern large city participated in this study. From the study, the following were obtained: 1. Various type of the performance assessment materials, such as observation report, peer evaluation, interview have been developed for the unit 'Plants around us.' 2. Students' understandings on the topics appeared to be sound, and the students' interest and cooperative problem-solving abilities have been cultivated through the small group activities. The science classes became more student-centered. 3. Teacher's burden has increased due to the practices of performance assessment, but it could be handled by teacher's commitment and management skills. 4. The students' responses to performance assessments were positive, in general.