• Journal of the Korean Society of Earth Science Education
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• v.9 no.3
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• pp.323-340
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• 2016

The purpose of this study is to investigate the effect of observing material on the phase change of moon considering the orbits of earth and moon for elementary school students. For this study, the material which shows the orbit of moon tilted at $5^{\circ}$ with the orbit of earth is developed. 110 6th grade students in an elementary school are sampled. They are divided into the experimental group and the control group. The lessons using the material developed in this study are implemented to the experimental group, and the lessons using the material proposed in ordinary textbook are implemented to the control group. The pre, post, delayed concept tests on the phase change of moon are administered to the students of the experimental group and the control group, and semi-structured interviews are conducted for each concept level. According to students' responses, the concept levels are divided into 'Phase recognition', 'Space viewpoint', 'Earth viewpoint', and 'No recognition'. The experimental group and the control group are homogeneous in the pre-test. The result of this study shows that the experimental group gains significantly more scores than the control group in the post and delayed tests. Also, in the post and delayed tests, more students of the experimental group are in the highest level 'Phase recognition' than the control group. Finally, students of the experimental group who were in the 'Phase recognition' and 'Space viewpoint' explain more scientifically than the students of the control group. Therefore the results of this study show that the observing material on the phase change of moon considering the orbits of earth and moon is effective.

• 대한공업교육학회지
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• v.41 no.2
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• pp.151-171
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• 2016

The purpose of this study is to verify the effect of Interdisciplinary course for improving the competency of collegiate Interpersonal & Cooperative Skills, Resources-Information-Technology Processing & Application and Communication. The course proved to be effective based on the result for examination of difference between the experimental group of 43 students who took the interdisciplinary course and the control group of 44 students who did not take that course of the second semester of H university in 2015. The study applied the method of Paired-sample T-Test to investigate the difference of Interpersonal & Cooperative Skills, Resources-Information-Technology Processing & Application and Communication and their sub-skills between the two participant groups. As a result, Interdisciplinary course had an effect on improvement of Interpersonal & Cooperative Skills and it's sub skills; however, it had no effect on improvement of Resources-Information-Technology Processing & Application and Communication competency and their sub-skills. The results provide theoretical and practical implications for the interdisciplinary course and core competence of college students. They suggest that interdisciplinary course design should be more careful to improve students' competency on Resources-Information-Technology Processing & Application and Communication competency than before.

• Journal of Radiation Protection and Research
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• v.21 no.4
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• pp.273-284
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• 1996

Embryos and fetuses are more sensitive to various environmental agents than are adults or children. The biological effects such as intrauterine death and malformation are closely connected with prenatal exposure very various agents. The sensitivity of these embryonic/fetal effects depends on the stage of pregnancy. From the viewpoint of fetal development, embryonic and fetal stages can be divided into three stages : Preimplantation, organogenetic and fetal. Each stage corresponds to 0 to 4.5days, 4.5 to 13.5days, and 13.5days of gestation in mice, respectively. Many studies on the biologcal effects of mice irradiated by ${\gamma}-rays$ at various stages during organogenesis and fetal period have been performed. Based on these results, the dose-effect and dose-response relationships in malformations, intrauterine death, or retardation of the physical growth have been practically modeled by the ICRP(International Commission on Radiological Protection) and other international bodies for radiation protection. Many experimental studies on mice have made it clear that mice embryos in the preimplantation period have a higher sensitivity to radiation for lethal effects than the embryos/fetuses on other prenatal periods. However, no eratogenic effects of radiation at preimplantation stages of mice have been described in many textbooks. It has been believed that 'all or none action results' for radiation of mice during the preimplantation period were applied. The teratogenic and lethal effects during the preimplantation stage are one of the most important problems from the viewpoint of radiological protection, since the preimplantation stage is the period when the pregnancy itself is not noticed by a pregnant woman. There are many physical or chemical agents which affect embryos/fetuses in the environment. It is assumed that each agents indirectly effects a human. Then, a safety criterion on each agent is determined independently. The pregnant ICR mice on 2, 48, 72 or 96 hours post-conception (hpc), at which are preimplantation stage of embryos, were irradiated whole body Cesium-gamma radiation at doses of 0.1, 0.25, 0.5, 1.5, and 2.5 Gy with dose rate of 0.2 Gy/min. In the embryos from the fetuses from the mice irradiated at various period in preimplantation, embryonic/fetal mortalities, incidence of external gross malformation, fetal body weight and sex ratio were observed at day 18 of gestation. The sensitivity of embryonic mortalities in the mice irradiated at the stage of preimplantation were higher than those in the mice irradiated at the stage of organogenesis. And the more sensitive periods of preimplantation stage for embryonic death were 2 and 48 hpc, at which embryos were one cell and 4 to 7 cell stage, respectively. Many types of the external gross malformations such as exencephaly, cleft palate and anophthalmia were observed in the fetuses from the mice irradiated at 2, 72 and 96 hpc. However, no malformations were observed in the mice irradiated at 48 hpc, at which stage the embryos were about 6 cell stage precompacted embryos. So far, it is believed that the embryos on preimplantation stage are not susceptible to teratogens such as radiation and chemical agents. In this study, the sensitivity for external malformations in the fetuses from the mice irradiated at preimplantation were higher than those in the fetuses on stage of organogenesis.

• Journal of Korean society of Dental Hygiene
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• v.22 no.5
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• pp.323-332
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• 2022

Objectives: This study aims to confirm the educational necessity and utilization of VR media. And it was conducted to prepare basic data necessary for the use of VR in various dental hygiene education in the future and the development of innovative practical training courses. Methods: Before and after using VR in oral radiology practice classes, learning interest (4 items), learning commitment (9 items), learning motivation (5 items), educational media preference (4 items), and satisfaction (10 items) were investigated and analyzed. Friedman two way ANOVA by ran a nonparametric analysis corresponding to repeated measures ANOVA was performed. The statistical significance level was 0.05. Results: It was found that there were statistically significant differences in learning interest, learning immersion, and learning motivation according to the type of oral radiology practice education medium (p<0.05). Conclusions: VR is expected that the use of learning media using VR will lead to students' interest, immersion, and learning motivation in class, and that positive learning effects on VR education media can be sufficiently obtained.