• Title/Summary/Keyword: 채동현

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The Changes of Preservice and Inservice Elementary School Teachers' Concepts of the Solar System Based upon Their Exposure to the Earth Motion Centric Solar System Model (지구운동 중심 태양계 실험 모형이 초등 예비교사와 초등학교 교사의 천문개념 변화에 미치는 효과)

  • Chae, Dong-Hyun
    • Journal of The Korean Association For Science Education
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    • v.24 no.5
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    • pp.886-901
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    • 2004
  • The purpose of this study was to document the changes in astronomical concepts for preservice and inservice elementary school teachers after being presented with the newly devised Earth Motions Centric Solar System Model. The subjects of the study were 31 preservice and 30 inservice elementary schools teachers in the Jeonbuk Province. First, the author investigated the naive theories of the subjects, and then, compared that data to the data obtained after their exposure to the model. The total number of items on the instrument for this study was 10. These items included questions about the motion of interior planets, the phases and sizes of interior planets, and the motion of exterior planets and comets. After analyzing the answers to the items before the experiment, the author was able to confirm the existence of the naive theories regarding astronomical phenomena. Also, after the experiment, the author was able to observe the conceptual change in thought of the preservice and inservice elementary school teachers. Results showed that learning through the new model had positive effects on the preservice and inservice elementary school teachers' conceptualization of the interior planets' motion, phases and sizes, and the exterior planets' motion.

Influence of an Astronomical Observation Program on Preservice Elementary Teachers Astronomy Achievement, Astronomy Teaching Efficacy Beliefs, and Scientific Attitude (천체관측을 통한 학습이 천문성취도, 천문교수효능에 대한 신념, 과학적 태도에 미치는 효과)

  • 채동현
    • Journal of Korean Elementary Science Education
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    • v.18 no.2
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    • pp.79-101
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    • 1999
  • Astronomy is a good area to introduce a student to the study of science. The student often questions what causes the change in seasons, in the day and right, and in the rotation of stars, etc. Attempts to find answers to problems related to these astronomical observations influence the student`s intellectual development. This study is to investigate the effect of running an astronomical observations program on the preservice elementary teachers' astronomy achievement, astronomy teaching efficacy beliefs, and scientific attitude. Students consist of twenty four preservice elementary teachers. Three instruments are used: one is the astronomy achievement test, which is of an essay type, and 5 items. The other is the astronomy teaching efficacy beliefs test, which is of a Likert scale type, and 22 items. Another is the scientific attitude test, which is of the Likert scale type, and 10 items. Data are collected before and after instruction in the astronomical observations program, through the use of these tests. Data are compared. The results are: \circled1There is a significant difference between before and after instructions in the astronomy achievement test(t=11.31, p=000). \circled2There is a significant difference between before and after instructions in the astronomy teaching efficacy beliefs test(t=5.98, p=.000). \circled3There is a significant difference between before and after instructions in the scientific attitude test(t=270, pde. There fore, the a=.013). As a result, running an astronomical observations program has an effect on the preservice elementary teachers' astrono my achievement, astronomy teaching efficacy beliefs, and scientific attituuthor urges the teacher to teach astronomy through the astronomical observations in school.

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A Qualitative Study of Preservice Teachers화 Change of Season (초등예비교사들의 계절변화 원인에 대한 질적 연구)

  • 채동현;변원섭;손연아
    • Journal of Korean Elementary Science Education
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    • v.22 no.1
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    • pp.109-120
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    • 2003
  • The purpose of this study is to observe, to analyze of the preservice teachers' naive theories about the change of season. And it is to find a instruction strategy which can solve problem about this. The general idea about the change of season is observed by the 3 methods which are simply explaining with words, explaining with pictures and models. The author is to find the similarity. difference and relationship which the preservice teachers have about the general idea about the change of season. The important changable primary factors, which can effect to the general Idea formation, are naturally dragged out through the observation of preservice teachers participation. For this study, 4 first year preservice teachers of one of national university of education are used. Before the interview. the author tries to form rapport with the preservice teachers. Experiment materials, pencil. paper, camcorder, digital recorder and interview note were used for the study with reflection of them just way they are. As the result of the interview. all of 4 preservice teachers had not being understand the concept about the change of season and the three ways of explanation methods were not matched each other, so it is revealed that the general Idea of the change of season, which the preservice teachers have, is not strongly formed. In spite of the repeated study of the change of season from elementary school to university, it has many problem about recognition of the general idea about the change of season which pre-elementary teachers have. Therefore it is needed to improve the experiment in elementary science text book and naive theories by the activity which is explaining the change of season in three dimension space. to prevent the naive theories which the preservice teachers may have.

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Copper Mineralization at Haman-Gunbuk Mining District, Kyeongnam Area (경남(慶南) 함안(咸安)-군북지역(郡北地域)의 동광화작용(銅鑛化作用)에 관(關)한 연구(硏究))

  • Park, Hee-In;Choi, Suck-Won;Chang, Ho Wan;Chae, Dong-Hyeon
    • Economic and Environmental Geology
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    • v.18 no.2
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    • pp.107-124
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    • 1985
  • More than fifty copper veins are emplaced around late Cretaceous granitoid stock in Haman-Gunbuk district, southernmost part of Korea. These veins cut both late Cretaceous granitoids and hornfels of Jindong formation which is intruded by the granitoids. The paragenesis of veins is nearly the same, consisting of (1) an early vein stage in which most iron oxide minerals, tourmaline and other silitcate minerals were deposited, (2) a calcite and quartz with base·metal sulfide stage and (3) late vein lets of barren calcite stage. Fluid inclusion studies reveal highly systematic trends of salinity and temperature during mineralization. Ore fluids of early vein stage were complex NaCl-KCl rich brines. Salinities of polyphase inclusions in quartz and scapolite in thie stage reached up to 72 wt.% and gradually decreased to 10.5wt. % in closing stage. Homogenization temperatures of inclusions in the beginning of this stage were up to $490^{\circ}C$ and then declined steadly to $290^{\circ}C$ in the late stage. Salinities of fluid inclusions in quartz and calcite of base·metal sulfide stage were 37.4~5.7wt. % and homogenization temperatures range from $373^{\circ}C$ to $170^{\circ}C$. Intermittent boiling of early vein fluid is indicated by fluid inclusions in quartz. Potassic alteration of granodiorite adjacent to early vein seems to be related to early saline vein fluid. Fluid inclusion data of base-metal sulfide stage of this area reveal nearly the same range as those of Koseong copper mining district about 30km apart from this area.

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An Analysis the Contents Related to a Subject 'Earth and Moon' from Elementary Science Textbooks of the 2009 Revised Curriculum and 2015 Revised Curriculum ('지구와 달' 주제와 관련된 초등학교 2009 개정 과학교과서와 2015 개정 과학교과서 내용 분석)

  • Lim, Cheonghwan;Chae, Donghyun
    • Journal of the Korean Society of Earth Science Education
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    • v.11 no.3
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    • pp.237-243
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    • 2018
  • The purpose of this study is to analyze the contents related to a subject 'Earth and Mooon' from elementary science textbooks of the 2009 revised curriculum and elementary science textbooks of the 2015 revised curriculum. For the research, the team selected and analyzed the contents of the 'Earth and Moon' unit in the elementary science textbooks of the 2009 revised curriculum and 2015 revised curriculum. As a result of the research, first, there has been no significant change in achievement standards of the curriculum as the science textbook revised from 2009 curriculum to 2015 curriculum. Second, the two curriculum did not differ much in specific textbook contents statement or development, but they showed much change in presentation of exploration activities in curriculum as well as the specific exploration activities presented in the textbooks. Third, compared to science textbooks of the 2009 revision the 2015 revision used more pictures and illustrations. Forth, there have been few changes related to experimental observation, but the activities to organize the unit in 2015 revision have been strengthened compared to the 2009 revision.

An Analysis of Creativity Factors, Family Backgrounds and Parenting Styles of Korean 3 Inventors in Korean Elementary Textbooks through Narrative Inquiry (내러티브 탐구를 통한 초등 교과서에 수록된 한국 발명가 3인의 창의성 요소, 가정환경, 부모 양육방식 특징 분석)

  • Chae, Dong-Hyun;Jo, Dae-Young
    • Journal of the Korean Society of Earth Science Education
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    • v.13 no.3
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    • pp.196-210
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    • 2020
  • According to many researches, invention education relates to improvement of students' creativity and problem solving skills, which are essential in future. So effective invention education is necessary. This study is to analyze creativity factor, family background and parenting style of three korean inventors in elementary textbooks through narrative inquiry and find similarities. As a result of study, all three inventors had intellectual curiosity, originality, productive thinking and sophistication. And they were born in wealthy families and had a member who support them. Also, their parents had secure attachments to them, actively participated in their education and were the first person who found their creativity.

An Analysis of Creativity Factors, Family Backgrounds and Pareanting Styles of 3 Great Korean in Their Childhood through Narrative Inquiry (내러티브 탐구를 통한 유년기 한국 위인 3인의 창의성 요소, 가정환경, 부모 양육방식 특징 분석)

  • Chae, Dong-Hyun;Jo, Dae-Young
    • Journal of the Korean Society of Earth Science Education
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    • v.14 no.3
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    • pp.212-224
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    • 2021
  • Early childhood education has a huge impact on the development of one's life. Therefore, it is necessary to implement effective education in childhood in order to develop abilities such as creativity, which is essential for future society. Thus, through narrative inquiry, the characteristics creativity factors, family backgrounds, and parenting styles of the three great Korean were identified, and the commonalities of the three were analyzed. Research shows that all three great people had intellectual curiosity and productive thinking skills. And most of them were born into economically rich families and had an environment where they could experience various things, and there were people who supported them. In addition, there were nurturing people around them who discovered talent and actively participated in education, and their parents formed a stable emotional attachment with their children.

Morphology and Histology of the Olfactory Organ in the Korean Endemic Species, Pseudobagrus koreanus (Cypriniformes, Cyprinidae) (한국 고유종 눈동자개 Pseudobagrus koreanus 후각기관의 형태 및 조직학적 특성 연구)

  • Kim, Hyun-Tae;Chae, Dong-Hyun
    • Korean Journal of Ichthyology
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    • v.34 no.3
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    • pp.153-159
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    • 2022
  • The olfactory organ of a Korean endemic species, Pseudobagrus koreanus, was investigated to describe its morphology and histology and analyze correlation between habitat environment and its ecological habits and characters, using a stereo microscope, a light microscope, and a scanning electron microscope. Its external morphology showed tubular anterior nostril at the tip of the snout and slit posterior nostril at the base of the nasal barbel. The olfactory chamber showed the rosette structure consisting of numerous lamellae radial and parallel to the medium raphe. The olfactory lamella has the sensory epithelium with olfactory receptor nuerons, supporting cells, basal cells, lymphatic cells, plasma cells and the non-sensory epithelium with stratified epithelial cells, mucous cells, lymphatic cells. In particular, 1) 41~43 (n=20) lamellae, 2) lymphatic cells and plasma cells, 3) mucous cells including neutral polysaccharid may be olfactory characteristics relevant to a stagnant or a standing habitat environment, nocturnal habit dependent on olfaction, and taxonomic characters compared at least to other catfish species.

Difficulties and Coping Methods Encountered by Authors of 5th and 6th Grade Science Textbooks: Based on Grounded Theory (초등학교 5, 6학년 과학교과서 집필자가 겪은 어려움과 대처 방법 : 근거이론을 중심으로)

  • Chae, Dong-Hyun;Yang, Il-Ho;Jung, Sung-An
    • Journal of The Korean Association For Science Education
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    • v.31 no.8
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    • pp.1121-1144
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    • 2011
  • This research is an investigation of difficulties encountered by authors of 5th and 6th grade science textbooks. The aim is to assist authors in creating more easily understandable textbooks in the future. In-depth interviews were conducted with 6 teachers who have previously taken part in the development of 5th and 6th grade texts. The responses given during these interviews were analyzed using open, axial, and selective coding as suggested by Strauss and Corbin (1998). The results are as follows: In open coding, related concepts were extracted and classified into 15 main categories and 46 sub-categories. In axial coding, the main categories were arranged into causal conditions, main phenomenon, context, intervening conditions, action and interactional strategies, and consequences wherein they were consistently related to each other based on Grounded theory. Finally, in selective coding, core categories were instilled whereby the texts being developed were categorized into conservative, progressive, and innovative to allow for easier interpretation. This was done to improve the overall quality of Science textbooks.

Biocontrol of Rhizoctonia solani Damping-off of Cucumber by Bacillus cereus KJA-118 (Bacillus cereus KJA-118을 이용한 오이 모잘록병의 생물학적 방제)

  • An, Kyu-Nam;Jung, Woo-Jin;Chae, Dong-Hyun;Park, Ro-Dong;Kim, Tae-Hwan;Kim, Yong-Woong;Kim, Young-Cheol;Cha, Gyu-Suk;Kim, Kil-Yong
    • Korean Journal of Soil Science and Fertilizer
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    • v.36 no.4
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    • pp.247-255
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    • 2003
  • A bacterium, KJA-118 showing a strong chitinase activity, was isolated and identified as Bacillus cereus. The strain produced maximum level of chitinase, when grown aerobically at $30^{\circ}C$ for 4 days in basal broth containing 1% colloidal chitin in the initial pH adjusted to 6.0. Among various carbon sources such as crab shell powder, chitin powder, colloidal chitin, and R. solani mycelium, maximum chitinase activity was found in culture broth supplemented with R. solani mycelium. When KJA-118 was incubated with R. solani, the cell wall of the fungus was found to be completely destroyed. SDS-PAGE and active staining results revealed that KJA-118 produced three isoforms of chitinase with molecular weights of 68 kDa, 47 kDa, and 37 kDa. When the suspension of KJA-118 was treated to cucumber seedlings, reducing rate of damping-off caused by R. solani was about 28.1%.