• Journal of the Korean School Mathematics Society
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• v.16 no.1
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• pp.265-287
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• 2013

The purpose of this study was to analyze the trends of domestic research on teacher knowledge in mathematics in terms of its conceptualizations of teacher knowledge, topics, methods, subjects, and content domains. For this purpose, the papers published in 9 professional journals during the recent 14 years (1999-2012) were analyzed by 5 criteria. The results of this study showed that the concept of PCK was the most frequent, whereas its subcategories appeared in different forms. The most frequent research topic was survey of teacher knowledge. The qualitative research methodology was more frequently used than the quantitative methodology, whereas mixed one was hardly used. The subjects for research included a little more elementary school teachers than secondary counterparts, but did similarly both pre-service and in-service teachers. Whereas both the research on number and operations in elementary mathematics education and the research on function in secondary were active, the rest of content domains were not. On the basis of these results, this paper provides several implications for future research direction in teacher knowledge in mathematics.

• Journal of The Korean Association For Science Education
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• v.29 no.6
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• pp.611-625
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• 2009

The purpose of this research is to investigate the characteristics of beginning science teachers' subject matter knowledge (SMK) as revealed in their classroom teaching methods. In this research, we explored six beginning teachers' classroom teaching episodes on the 'work and energy' unit. Using open-ended interviews with the teachers and group discussions taking place on a regular basis to analyze and compare the classes of six beginning teachers, we extracted the features of beginning science teachers' SMK. Using grounded theory methods, the characteristics of beginning science teachers' SMK drawn from this research are: (1) beginning teachers' positivistic epistemology on science, (2) claiming the teacher's authority based on rich subject content knowledge, and (3) beginning teachers' science elitism. These epistemological characteristics are realized such PCK as (1) representational errors caused by the teacher's own science misconception, (2) doing harm to students with too much content knowledge, (3) sporadic content presentation lacking a focus, and (4) surplus class hours with lack of effective science teaching explanations. Suggestions for alternative perspectives on science SMK are presented by experienced teachers. In conclusion, science teachers' SMK is necessary, but not sufficient, for effective teaching. Science teachers' SMK does have an effect on science teaching, mediated by other types of teacher knowledge. The beginning teachers need a systematic support to transform their SMK into a viable PCK.

• Korean Journal of Child Education & Care
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• v.17 no.3
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• pp.49-63
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• 2017

This study aims to investigate the effect of early childhood teachers' mathematical attitude on their mathematics teaching efficacy and to prove the moderating role of pedagogical content knowledge (PCK) in mathematics, which we selected based upon previous literatures. To explore the effect of early childhood teachers' mathematical attitude on their mathematics teaching efficacy and the moderating role of PCK in mathematics between them, This study randomly sampled 500 early childhood teachers who work at child care centers and kindergartens in Seoul, Kyunggi province and Kangwon province and collected their responses by questionnaires. Mathematics teaching efficacy was measured with mathematics teaching efficacy scale for early childhood teachers developed by Luo (2000) and translated by Jung (2001a). Mathematical attitude was measured with Smith (2000)'s scale which we translated for this study. To measure the pedagogical content knowledge in mathematics, we revised Hong(2012)'s scale to be applicable for early childhood teachers. Direct effect of mathematical attitude on mathematics teaching efficacy and the moderating effect of PCK in mathematics were analyzed by multiple regression analysis using IBM SPSS 21.0. Study results demonstrated the significant direct effect of mathematical attitude on mathematics teaching efficacy. Also, the moderating effect of PCK in mathematics was also proved to be significant. That is, if the teacher has high level of pedagogical content knowledge in mathematics, the positive effect of mathematical attitude on mathematics teaching efficacy was even more enhanced. This results supports the current finding where PCK in mathematics functions as a moderating variable between mathematical attitude and mathematics teaching efficacy. Thus, our study is expected to provide relevant contents that should be covered during teacher education, which aims to improve early childhood teachers' mathematics teaching efficacy.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.375-382
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• 2006

This study was conducted to investigate the effects of dietary herbal plant mixture on growth performance, blood immunological parameters, fecal VFA and NH3-N concentrations in growing pigs. The dietary treatments were 1) NC (negative control; antibiotics-free diet), 2) PC (positive control; NC diet added 0.16% antibiotic), 3) NCK0.2 (NC diet added 0.2% herbal plant mixture (koppuul??)) and 4) PCK0.1 (PC diet added 0.1% herbal plant mixture (koppuul??)). Eighty crossbred (Landrace×Yorkshire×Duroc) pigs (16.35±0.05kg average initial body weight) were used for 42 days. The pigs were assigned to the treatments according to body weight and each treatment had 5 replicates of 4 pigs per pen in a randomized complete block design. During the whole experimental period, PCK0.1 and PC treatments had significantly higher ADG than NC treatment (P<0.05). Gain/feed of pigs fed PC diet was higher than that of pigs fed NC diet (P<0.05). For blood immunological parameters investigations, white blood cells (WBC) counts and IgG level increased in the pigs fed PC, NCK0.2 and PCK0.1 diets compared to pigs fed NC diet. In addition, higher (P<0.05) serum lymphocyte concentration was found in PCK0.1 treatment compared to NC treatment. NH3-N concentration in pigs fed NCK0.2% diet was lower than that in pigs fed PC and NC diets. There were no significant differences in DM and N digestibilities among the treatments. In conclusion, the results suggested that the dietary additions of herbal plant mixture or antibiotics increase ADG, the concentrations of WBC counts and IgG, lymphocyte, while decrease NH3-N concentration in feces.

• Journal of the Korean Chemical Society
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• v.67 no.6
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• pp.441-461
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• 2023

This study explore characteristics of teaching orientation and pck of science teachers in online-offline mixed learning environment. Data consisted of open-ended survey, semi-structured interview, class observation, field notes from 12 science teachers. We categorized teaching orientation considering both science education goals and science teaching·learning orientation. There were 8 different teaching orientations such as 'understanding science concepts-lecture centered' 'constructing science concepts-inquiry based' 'applying science concepts and inquiry-inquiry based' 'applying science concepts and inquiry-lectured centered' 'analyzing and judging science information-inquiry based' 'developing scientific attitude-inquiry based' 'developing scientific attitude-lecture centered' and 'developing perception of interrelationships among science, technology, and society-inquiry based'. Teachers with inquiry based teaching·learning orientation seemed to have knowledge of science curriculum specific to online learning environment for student inquiry. While teachers with 'understanding science concepts-lecture centered' teaching orientation appeared to have questioning strategy of checking student understanding and strategy of repeating a lecture, teachers with 'constructing science concepts-inquiry based' teaching orientation appeared to have knowledge of instructional strategies to perform online group activities targeting student construction of knowledge and to replace face-to-face group activities with virtual experiments and individual experiments. While teachers with 'understanding science concepts-lecture centered' teaching orientation did not show knowledge of student science learning, teachers with 'constructing science concepts-inquiry based' teaching orientation appeared to have knowledge of student difficulties in inquiry based learning.

• Journal of the Korean earth science society
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• v.32 no.5
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• pp.494-503
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• 2011

During the last three decades, earth science has been re-conceptualized as an interdisciplinary discipline entitled Earth System Science (ESS), which is based on knowledge of the physical earth system and human impact on the earth. While there is increasing effort to teach earth as a system in K-12 education, teachers' preparedness of to teach earth system is still in its infancy. This article focuses on reviewing the literature of teachers' knowledge of earth systems and of how teachers' knowledge of subject matter affects their teaching practice and pedagogical content knowledge (PCK). First, the study investigated a literature of PCK in general as well as in science teaching. Then this study duscuss what teachers' subject matter knowledge (SMK) is and what it means to be in teaching earth system science. Third, a literature of teachers' knowledge of earth system was reviewed. Finally, a number of suggestions and implications are made as to what teacher education program should do to better prepare future teachers to teach earth systems.

• Journal of Korean Home Economics Education Association
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• v.29 no.1
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• pp.35-56
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• 2017

The purposes of this study were to develop an instrument to examine the latent domains to measure H-PCK and verify the reliability and validity of the instrument. To accomplish these purposes, instrument item development, content validity, pilot study, and main study were conducted. The results were as follows. First, based on a review of extant literature, 29 items for H-PCK were developed. Seven items were deleted from the original instrument after determining content validity by 10 in-service Home Economics teachers, which resulted in the 22 items of 3 domains(Knowledge of perspective on Home Economics Education(KP), Knowledge of Home Economics curriculum(KC), Knowledge of Home Economics instructional strategies(KI)). Second, data were collected from 137 Home Economics teachers via mail survey for pilot study to establish reliabilities for each individual domain and across the domains based on Cronbach's ${\alpha}$ and item-total correlation. The result showed good reliabilities in the cut-off value of .7 and .5 for Cronbach's ${\alpha}$ and for item-total correlation respectively. Third, the main study was performed with 220 Home Economics teachers via e-mail survey and the reliability and validity tests were conducted. The reliability test results showed good reliabilities. The model for confirmatory factor analysis(CFA) provided a good fit to the data (e.g., CFI=.92, RMSEA=.06, SRMR=.05) to evaluate construct validity. The three domains of KP, KC, and KI demonstrated the acceptable convergent and discriminant validities in each individual domain and over domains. Thus, the instrument in this study may be utilized to measure H-PCK. Finally, criterion-related validity was performed to examine the extent to which the three domains are related to teacher efficacy with Pearson correlation (${\rho}$). It was relatively highly correlated at ${\rho}=.7$. In addition, the higher H-PCK the Home Economics teachers had, the higher teacher efficacy they had. The final instrument consisting of 22 items from 3 domains were determined through the entire procedure.

• The Mathematical Education
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• v.56 no.4
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• pp.407-434
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• 2017

The purpose of this study is to develop and verify the TPACK measurement tool for middle and high school mathematics teachers in the Korean context. Also, by clarifying the relationship between subordinate factors of Mathematics teachers' TPACK, an attempt was made to provide suggestions on the designs and directions for the in-service and pre-service teacher education and the programs for improving mathematics teachers' TPACK in the future. In order to achieve this goal, TPACK factors of mathematics teachers were extracted by reviewing literature on PCK, MKT, and TPACK. Then, content validity, basic statistical survey, reliability verification, exploratory factor analysis, confirmatory factor analysis, and structural equation model verification were conducted sequentially. At first, preliminary analysis was carried out on 79 mathematics teachers, and 76 items excluding the items with extreme value and reliability were included in the basic statistical analysis. And secondly, an exploratory factor analysis was conducted on 376 mathematics teachers, and this instrument consisted of 7 subordinate factors(CK, PK, TK, PCK, TCK, TPK, TPACK) and 61 items. Also by conducting confirmatory factor analysis and structural equation model test with 254 mathematics teachers, the measurement tool was confirmed the validity and reliability through statistically significant analysis. Then, the importance of integrated knowledge was confirmed by looking at the relationship between the TPACK factors of in-service mathematics teachers. The integrated knowledge(PCK, TCK, TPK) has played a crucial role in the formation of TPACK rather than the knowledge of CK, PK, and TK alone. Finally, the validity of TCK was confirmed through the structural equation modeling of TPACK. TCK not only directly affected TPACK, but also indirectly through TPK. According to these affirmative results, this measurement tool is claimed to be suitable for measuring the factors of Mathematics teachers' TPACK, and also the structural equation model can be regarded as a suitable model for analyzing the structural relationship of mathematics teachers' TPACK.

• Journal of Life Science
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• v.20 no.2
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• pp.213-218
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• 2010

In the present study, we investigated anti-proliferative activities of capsaicin and gene expression changes in response to capsaicin treatment in human colorectal HCT116 cells. The results showed that capsaicin decreased cell viabilities in a dose dependent manner and induced global gene expression changes. We found that 103 genes were up-regulated more than twofold, whereas 153 genes were down-regulated more than twofold by $100\;{\mu}M$ capsaicin treatment. Among the up-regulated genes, we selected 4 genes (NAG-1, DDIT3, GADD45A and PCK2) and performed RT-PCR to confirm the microarray data. We found that $100\;{\mu}M$ of capsaicin increased tumor suppressor p53 gene expression. In addition, the results showed that NAG-1, DDIT3 and GADD45A expressions were not dependent on p53 presence, whereas PCK2 expression. The results of this study may help to increase our understandings of the molecular mechanism of anti-proliferative activity mediated by capsaicin in human colorectal cancer cells.

• Journal of The Korean Association For Science Education
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• v.33 no.6
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• pp.1219-1236
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• 2013

The purpose of this study was to investigate the association between subject matter knowledge (SMK) and pedagogical content knowledge (PCK) for science teachers. To this end, a total of 26 secondary Earth science teachers participated in this study and a concept diagnostic questionnaire and a lesson planning task of atmospheric pressure were devised to give an indication of participating teachers' SMK and PCK, respectively. The results of this study are summarized as follows: First, participating teachers showed a variety of SMK levels about atmospheric pressure. Second, teachers at high level of SMK focused on 'supplementary' and 'fundamental' curriculum contents for in-depth conceptual understanding, but teachers at low level of SMK, on the contrary, stressed 'applicative' curriculum contents. Third, teachers at high level of SMK grasped students' misconceptions and difficulties in learning atmospheric pressure far more concretely than teachers at low level of SMK. Lastly, teachers at high level of SMK showed a tendency to use learner-centered instructional strategy by utilizing students' prior knowledge, but teachers at low level of SMK were inclined toward teacher-directed concept explanation. Based on this study, some implications for effective science teacher preparation programs were also discussed.