• 한국초등과학교육학회지:초등과학교육
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• 제30권4호
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• pp.524-534
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• 2011

This study is to ascertain pre-service teachers' conceptions for the causes of season change, to verify their conceptional mistakes, and to analyze how their conceptions are changed while presenting Disproof-Experiment Model where they cannot explain it with their current conceptions. 32 junior students of Education universities, pre-service elementary teachers, located at the middle of Korea participated in this research including two interviews and one experiment activity. As a result of analyzing of the data, the pre-service teachers held diverse conceptions for the causes of season change such as to mistake the phenomena, the distance between the earth and the sun, the tilting of the rotation axis and the revolving around the sun while changing the tilting direction of the rotation axis as the cause. After applying Disproof-Experiment Model designed by the researchers in order to change the current conception above, the conception changes of the pre-service teachers were investigated. Diverse Disproof-Experiment Models were used differently depending on the pre-service teachers' conceptions. As a result of the application of Disproof-Experiment Model, 26 out of 28 pre-service teachers were changed to scientific conceptions. It was determined that in order to modify pre-service teachers' conceptions, designing and presenting the Disproof-Experiment Model appropriate to their conceptions are effective after analyzing their conceptions. In case of conceptions that pre-service teachers feel difficult, it was established that unraveling experiment models prescribed after investigating the preconceptions and identifying the misconceptions are important.

• KSBB Journal
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• 제27권6호
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• pp.361-366
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• 2012

We investigated the anti-diabetic activity and enzymatic activity of 24 commercial doenjang samples certified for traditional foods. Twenty four doenjang samples showed the wide ranges in enzymatic activities (protease activities 0-50.45 unit/g, ${\alpha}$-amylase activities 0-675.9 unit/g, ${\beta}$-amylase 13.6-308.6 unit/g), and there were no difference in enzymatic activity by the producing region. To evaluate the potential anti-diabetic activity of 24 doenjang samples, we examined the effect of doenjang methanol extract (DME) on 2-[n-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amyno]-2-deoxy-d-glucose (2-NBDG) uptake. Ten samples among 24 samples significantly stimulated the uptake of 2-NBDG. When the cells were treated with DME at 400 ug/mL, No. 17 and 23 specially stimulated 2-NBDG uptake by 1.23-fold and 1.25-fold, respectively, compared with untreated control cell. And there were no cytotoxicity in the C2C12 cells treated with DME at concentration of 500 ug/mL. Among 24 samples, No. 6, 7, 12, 21 and 24 showed the ${\alpha}$-glucosidase inhibitor activity at concentration of 10 mg/mL; however, they were less effective than acarbose which is a commercial ${\alpha}$-glucosidase inhibitor.

• 대한지구과학교육학회지
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• 제5권2호
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• pp.189-196
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• 2012

This study was conducted using the phenomenological research method to collect and analyze high school students' opinions about fusing "science" textbook that reflect the 2009 Revised Curriculum. Ninety six students were chosen to be participants from 32 high schools that selected by city and province. The data collection was carried by individual interviews and group discussions. The results are as follow; students' opinions were summarized to 50 themes, and then classified to 9 theme clusters and 2 categories. Students' opinions were divided into a positive position - "it is good because interesting material associated with life", "the structure of textbook is good", "teachers' efforts make class interesting", and "it will help in career choices"- and negative position - "the content is difficult to understand", "the configuration is complex", "I have less interest about it because it doesn't related College Scholastic Ability Test", "teacher's explanation is insufficient", and "it is not associated with career choice"-. The living-related material and story-telling configuration received good reviews from students. On the other hand, the configuration of topics makes many concepts to use, so students have difficulty understanding the content and pointed out the lack of teachers' explanations about unfamiliar areas. In order to solve the difficulties, variety teaching material for fusing "science" will be developed.

• 대한지구과학교육학회지
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• 제6권1호
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• pp.40-49
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• 2013

The purpose of this study was to investigate a motivation system about science learning and interest in science among elementary, middle & high school students and analyze on the their relations. For this, the questionnaires on interest in science that developed by Kind et al., (2007) were selected and translated. After that, second-grade 80 students, fourth-grade 87 students, sixth-grade 107 students, eighth-grade 123 students and eleventh-grade 128 students were required to accomplish a questionnaire on behavioral inhibition system/behavioral activation system about science learning (SL-BIS/BAS), interest in science. Based on these materials, SL-BIS/BAS by student's variables and relations of between the system to interest in science have been analyzed. The result of this study shows the followings. First, the sensitivity about SL-BIS was no significant difference in School levels. But sensitivity about SL-BAS and interest in science in elementary and high school was higher than it in middle school. Second, there were low negative correlation with SL-BIS and interest in science, and relatively high positive correlation with SL-BAS and interest in science. Through the results of this study, relations of motivation to related variables, and the motivation by student's variables are identified. These results would be helpful for teachers to understand the difference about motivation by students' variables and to make a plan for the appropriate strategies for learners.

• 생명과학회지
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• 제9권1호
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• pp.69-75
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• 1999

Genus Drosophila에서 melanogaster complex내의 4종에 대한 유연관계 해석을 위하여, insemination test에 의한 premating isolation, 잡종형성 여부에 의한 postmating isolation, 형태 형성에 관한 영향 및 종 분화 관련 유전자의 특징 등을 대상으로 조사하였다. 종내 교배에서는 insemination rate는 96∼99% 정도였고 종간 교배에서는 정역 교배간에 심한 변이를 보였으며 D. melanogaster 암컷은 타종 수컷과의 교배에서 전반적 성공률이 높으며 D. sechellia 수컷은 타종 암컷과의 교배에서 비교적 높은 교배 성공률을 보였다. 종간 잡종 형성에서는 특히 simulans, mauritiana 및 sechellia 사이에서 임성이 완전한 암컷과 불임의 수컷이 형성되어 이들 3종이 더욱 근연임을 시사하고 있다. sex comb과 genital arch에 대한 잡종의 형태 형성에 관한 영향은 대부분이 polygene에 의하여 조절되고 있음을 알 수 있었다. D. melanogaster와 simulans에 있어서 분화 관련 유전자로 추정되는 잡종의 온도 감수적 생존도는 주로 simu-lans의 X 염색체상의 유전자에 의하여 조절되고 있음이 분석되었다.

• 한국식품과학회지
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• 제23권5호
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• pp.546-553
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• 1991

전통안동식혜를 발효 후 저장하는 동안에 안정제에 의한 침전억제 효과와 관능검사, 생균수와 산생성균수 및 점도의 변화를 조사하였고 식혜저장중 쌀표면과 내부를 전자현미경으로 관찰하였다. 각종 안정제중 0.3%의 carrageenan을 첨가시 안정성이 가장 좋았으며 산생성 균수는 $4^{\circ}C$에 저장한 경우 3일까지는 급격히 증가하여, $22.92{\times}10^{7}/ml$였으나 20일에는 $1.2{\times}10^{6}/ml$로 감소하였다. 안정제 0.3%의 Carrageenan의 첨가정도와 지역, 그리고 식품안정제의 첨가정도와 처리구간 간의 상호작용 효과는 맛에 대하여 각각 현저한 통계적 유의성을 나타내었다.

• 한국균학회지
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• 제40권1호
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• pp.60-64
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• 2012

한국식품연구원으로부터 분양받은 효모 49종과 곰팡이 34종등 총 83종의 진균류들의 PD broth 배양 농축물들의 생리 기능성을 측정 하였다. 효모 배양 농축물중에서는 Saccharomyces cerevisiae Y277-3 과 Saccharomyces cerevisiae Y157-1 의 PD broth 배양 농축물들의 tyrosinase 저해활성이 각각 42.7%와 41.2%로 생리기능성중 제일 높은 활성을 보였다. 또한 곰팡이 배양 농축물에서는 Aspergillus oryzae CN20-3-1-4 배양 농축물의 항산화 활성이 15.8%로 가장 높았으나 대체로 낮은 생리기능성을 보였다. 시험 진균류들의 생리기능성중 가장 높았던 Saccharomyces cerevisiae Y277-3 의 세포내 tyrosinase 저해물질은 이 효모를 PD broth 에 접종하여 $30^{\circ}C$에서 24시간 배양 하였을때 가장 많이 생산 되었다.

• 대한지구과학교육학회지
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• 제8권1호
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• pp.66-75
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• 2015

This study is to investigate an argumentation level for elementary school students after analysing an argumentation structure about a socio scientific issue(SSI), and inquire a change of the decision-making according to the refutation materials and empathic situation. This data was collected from the semi-structured interview with the 14 students, grade 6th. For this, the first stage is to present the reading materials about the SSI to the students, let them decision-making and make them argue pro and con about the SSI during the interview. After that, facing with the refutation materials against the existing contention and the empathic situation, the change of the decision-making of the students was conducted. After the research, the level of the argumentation of the students was low, and the students who didn't have the background knowledge about the theme made the decisions according to the values, emotions or intuitions of their own. And the decision-making of the students changed more when presented with the refutation materials and the empathic situation, they were difficult to make the decision because of new information and various stances. Besides, they lacked in the ability that recognize the situation related with their own life, just used the fragmentary knowledge associated with value of life respect. Through these result, it is necessary to produce the refutation materials and empathic materials about the SSI to the students for improving the level of argumentation.

• 대한지구과학교육학회지
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• 제8권1호
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• pp.56-65
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• 2015

The purpose of this study is to investigate how elementary school student understands or students understand the illustrations on the phase change of the Moon in science textbook and to find out how textbook illustration helps students form the conception of the phase change of the Moon. To identify this purpose, we selected illustrations on the phase change of the Moon in the science textbook revised in 2007 and 2009 revised science textbook. For this study we selected and interviewed 20 students in the fifth grade. We integrated all data collected through interviews and created a transcription and a protocol and then, confirmed scientific conceptions related to the phase change of the Moon in students' illustration reading. The result are as followings: First, students read more scientific conceptions related to the phase change of the Moon in illustration of the 2009 revised science textbook which is presented with the universal observer's view point and the earth observer's view point. Second, students who find meaning in the various elements of the illustration and interpret with the integration of the various elements, get a lot of relevant information from illustration. All students have no differences recognizing the elements presented in illustration. But there are differences of contents of illustration reading depending on how students interpret the illustrations with integration of the various elements and if students cannot figure out the four scientific concepts needed to understand the phase change of the Moon, they ignore the information provided by illustration or analysis in their own way according to information provided by illustration. So misconception appears in this process.

• 생태와환경
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• 제33권1호통권89호
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• pp.9-22
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• 2000

본 연구에서는 남조류의 독성물질 배출 및 분해양상을 밝히고자 대청댐 지류인 옥천천의 스컴을 채취, 실험대상으로 하였다. Light와 dark 상태로 분리${\cdot}$배양한 배지에는 조사를 하는 동안 다른 영양염류는 첨가하지 않았다. 그 결과 세포내에서 microcystins의 총량은 세포수가 감소함에 따라 감소하였으며 Microcystis aeruginosa의 현존량과 비교하였을 때 light와 dark 상태의 경우 $r^{2}$값이 각각 0.96과 0.97로 높은 상관관계를 보였고 dark 상태에서 보다 더 빠른 감소추세를 보였다. 또한 세포에서 수체로 용존되는 microcystins의 량은 세포내에 존재하는 양의 극히 일부임을 확인 할 수 있었고 세포내에 분포하는 microcystins의 농도는 종류에 따라 차이를 보여 microcystin-RR>-LR>-YR의 순으로 존재하는 것으로 나타났다. 이러한 결과는 옥정호과 제천천을 대상으로 한 수심별 조사에서도 동일한 양상을 보였다. 수체에서 검출된 microcystins의 양은 점성물질의 양과 함께 light와 dark 상태에 따라 뚜렷한 차이를 보였으며 light의 경우 $r^{2}$값이 -0.75의 역의 상관관계를 보였다. 남조류 세포 및 microcystins에 대한 light와 dark 상태에서의 서로 다른 농도 결과는 배양 상태에 따른 미생물의 분해양상의 차이와 미생물에 대한 점성물질의 영향으로 추정된다.