• Journal of the Korea Society of Computer and Information
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• v.25 no.7
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• pp.225-237
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• 2020

This study verified the effects that a programming-based TPACK education program, through design-based research on TPACK, had on pre-service teachers. The research subjects were pre-service teachers attending teacher training at a university in Korea, and 129 control groups and 126 experimental groups were recruited through lectures. The treatment used a TPACK educational program developed in a design-based study (Kim & Lee, 2019). A TPACK test tool developed by Park and Kang (2014) was used. The test results were analyzed via independent sample t-test and paired sample t-test. The results show that the programming-based TPACK education program (first cycle) was only effective in improving TPK and TPACK, but an effective educational program was developed to improve PCK, TCK, TK (second cycle), PK (third cycle), and CK (final cycle). This design-based research therefore confirmed the development of a programming-based TPACK education program that was effective for improving the TPACK of pre-service teachers.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.996-1001
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• 2007

To investigate whether sulindac, sulindac sulfone, and sulindac sulfide could affect cancer cell viabilities, human colorectal HCTl16 cells were treated with 10 ${\mu}M$ of each NSAID. Among treated NSAms, sulindac sulfide dramatically decreased the cell viabilities detected by MTS and the cytotoxic effect showed dose-dependent manner. To understand the molecular mechanism of cell death in response to sulindac sulfide treatment, we performed oligo DNA microarray analysis. We found that 23 genes were up-regulated more than 2 folds, whereas 33 genes were down-regulated more than 2 folds by treatment of 10 ${\mu}M$ sulindac sulfide. Among the up-regulated genes, we selected 3 genes (NAG-1, DDIT3, PCK2) and performed RT-PCR and quantitative real-time PCR to cofirm microarray data. The results of RT-PCR and real-time PCR were highly accorded with those of microarray experiment. As NAG-1 is well-known gene as tumor suppressor, we detected changes of NAG-1 expression by 10 ${\mu}M$ of sulindac, sulindac sulfone, and sulindac sulfide. The results of RT-PCR and quantitacve real-time PCR indicated that sulindac sulfide was the strongest inducer of NAG-1 among treated NSAIDS. This result implies that induction of NAG-1 by sulindac sulfide plays important role in cell death of colorectal cancer. Overall, we speculate that these results may be helpful in understanding the molecular mechanism of the cancer chemoprevention by sulindac sulfide in human colorectal cancer.

• The Mathematical Education
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• v.45 no.1 s.112
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• pp.75-96
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• 2006

The purpose of this study was to analyze how elementary pre-service teachers learned the pedagogical content knowledge of mathematics and to understand the challenges and difficulties that they experienced in the course of student teaching. A qualitative case study provided an in-depth description of the whole three weeks of student teaching process. Four pre-service teachers and two mentor teachers participated in this study. Multiple data collection techniques were used; classroom observations, in-depth interviews, document analysis, and researcher's field notes. The results of this study showed how pre-service teachers learn PCK of mathematics in designing mathematics lessons, understanding mathematics learners and delivering mathematics lessons and what are the difficulties and challenges they experienced. Finally this study discussed about some suggestions to pre-service program and future research.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.121-124
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• 2001

Using ordors with the different concentration of essential oils, e studied the effect of a pleasant olfactory stimulation on physiological responses. we examined psychological response, mental task and changes in cardiac, immunity and EEG in responses to 150times solution (feel easily) and 500times solution (feel with difficulty) which of essential oil (called PCK) were diluted in propylene glycol, and neutral (water). The 150times solution that was felt pleasant produced significant differences (p<0.05) in relative power change of beta activity in the left frontal region (Fp1, F3, F7) of the brain, and heart rate (HR) deceleration after mental task. these results are consistent with substantial research that has documented cardiac and EEG responses to pleasant stimuli. What is more, 150times solution increased the concentration of s-IgA know as an index of immunity.

• Korean Journal of Human Ecology
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• v.21 no.4
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• pp.629-647
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• 2012

This study explored what Korean college students, especially preservice teacher in early childhood education, experienced and how they constructed the meanings of experiences about their subject- matter course (early childhood mathematics education) taught in English. One cohort- 20 senior students- majoring in early childhood education in a 4-year university was participated in this study. Using action research method and narrative research method, data were analyzed. The findings were as follows: 1) preservice teacher experienced some difficulties to construrct professional knowledge through English. 2) They challenged to overcome these difficulties through active participation. 3) They got supports from instructor and peer group. 4) They accomplished the course with self-satisfaction. 5) They experienced the conflicts between social requirements and personal needs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.249-252
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• 1997

Electroluminescence(EL) devices based on organic thin layers have attracted lot of interests because of their possible application as large-area display-emitting display. One of the problems of such devices is lifetime of the cell, where the degradation of the cell is partially due to the crystalliyzation of organic layers. In large part, this problem can be solved by using a multilayer device structure prepared by vapor deposition technique. In this study, blue light-emitting multilayer organic electroluminescence devices were fabricated vsing Poly (9-vinylcarbaEole) (PVK) and 2- (4-tert-butylphenyl)-5-(4$^{#}$-bis-phenyl) 1,3,4-oxadiazole (PBO) as hole trasport and electron transport material, respectively, where trim(8-hyd roxyquinolinate) aluminum (Al $q_3$) was used as a luminescenct material. A cell structure of glass sub- strate/indume-tin-oxide(ITO)/PCK/Al $q_3$/PBD/Mg:In was employed. Blue emission peak at 510nm was observed with this cell structure.e.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.191-192
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• 2012

옥외 LED 조명은 수 많은 응용 분야가 있고, 출력 전력 크기에 따라 전력단이 single-stage 와 two-stage 구조로 나뉜다. Single-stage 구조는 낮은 전력 LED 조명에 적합하지만, 60~70W 이상에서는 효율이 떨어지고 변압기의 크기가 커져서 적용하기가 힘들다. 반면에 two-stage 구조는 보통 큰 전력이 필요한 응용분야에 사용되지만, 낮은 부하에서 낮은 역율을 나타내므로 넓은 출력전력 범위를 갖는 분야에 사용되기 어렵다. 이 문제를 해결하기 위하여 본 논문은 pulse duty cycle, pulse frequency modulation 제어 방법을 갖는 interleaved single-stage flyback AC-DC converter 를 제안한다. 제안된 컨버터는 입력 전압이 낮고 부하가 큰 경우 높은 효율을 보이고, 입력 전압이 높고 부하가 아주 작은 경우에도 높은 역율과 낮은 전류 왜곡을 보인다. 그 결과 하나의 AC-DC 컨버터를 넓은 출력전력 범위를 갖는 LED 조명분야 적용시킬 수 있다. 제안된 컨버터의 타당성을 검증하기 위하여 81W prototype을 가지고 실험하였다.

• Journal of Korean Elementary Science Education
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• v.26 no.3
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• pp.295-308
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• 2007

The purpose of the study is to develop an effective model of a science teachers' professional development program. This study consists of two parts: (1) the theoretical review of science teachers' professional development and (2) a case study of a science teachers' professional development programme in the UK. After reviewing recent research on pedagogical content knowledge and new approaches to educational research, the following suggestions emerged: (1) Continuing Professional Development(CPD) should be embedded in teachers' real practice in the classroom and (2) embedded in the everyday life of learners' within the community. (3) CPD should support the development of teachers' communities of professional practice. The case study of 'CPD through Portfolios of Evidence' in the British programme indicated that collecting explicit evidence of good practice in the classroom and establishing agreement as to what constitutes good practice in a teachers' community helped teachers' professional development. Finally, what emerged from the case study of the CPD programme in the UK and the theoretical review of PCK was the following. An effective CPD model of science teachers should comprise these three stages: (1) providing opportunities of professional development, (2) changing practice in the classroom and research, and (3) spreading and sustaining change. The whole process is circular.

• Journal of the Korean School Mathematics Society
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• v.16 no.1
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• pp.1-29
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• 2013

The main goal of the research is to develop instructional consulting manual to help math teachers improve classroom teaching. Improving the quality of teaching in schools is stressed as a central focus of meaningful classroom instruction and high quality education. In this research, teaching consulting was defined as an activity that covers reflection process oriented towards formative assessment and continuing professional development. Within this context, subject-specific teaching consulting and teaching professionalism with focus on PCK was reviewed. Further, the questionnaire survey was conducted to investigate the current situation of teaching consulting and teachers' needs for consulting. And also, specific examples of subject-specific consulting based on our previous consulting experiences in math classes were shown. Alternative ways to improve subject teaching were derived through the conferences where consultants and consultees analyze video-taped lessons conducted by the consultees. By those results, a manual for invigorating teaching consulting was developed. The contents of the manual consists of setting conditions of teaching consulting and its implementation in the classroom teaching. The first part of the manual contains steps to establish teaching consulting system, the qualification and role of the consultant, system evaluation, etc. The second part of the manual presents the pre-preparation, prescription and implementation and follow-up management steps. Each part of the manual provides consultants with specific guidelines for each step. Finally, recommendations for making policy related to ways to invigorate teaching consulting was suggested. It is expected that specific examples and cases of subject-specific teaching consulting presented in this research will be used to narrow the gap between theory and practice of teaching consulting, and to help math, science and English teachers develop teaching professionalism.

• Journal of Life Science
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• v.26 no.8
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• pp.895-903
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• 2016

This study was carried out to discover the response of cucumber (Cucumis sativus L.) senescence- associated genes (SAGs) to several plant hormones in detached and developing cotyledon. Accordingly, a collection of cucumber SAGs were examined to characterize their gene expression response through semi-quantitative RT-PCR. Cotyledons were excised at day 14 after seed sowing from plantlets, then incubated in 100 μM each of IAA or zeatin solution for up to 4 days in light and darkness. They were collected at 2-day intervals and used for total RNA extraction and subjected to RT-PCR. Gene expression levels of several cucumber SAGs were significantly changed during the incubation period. More than five cucumber SAGs involving SAG 60 responded to the IAA and zeatin treatment. In the ethylene response study, cotyledons were exposed up to 10 days by ethylene gas. Most of the cucumber SAGs did not show immediate response to ethylene in green cotyledon. The exceptions were PCK, SAG 158, and SAG 288 genes, which responded after 1 day of exposure to green cotyledon, while ICL and SAG 281 revealed strong responses after 10 days of being exposed to yellowing cotyledon. These results suggest that several cucumber SAGs react actively in response to starvation or senescence against exogenously applied stimulus. This induced senescence response is able to understand the SAGs role in lipids and amino acids metabolism partly and function in organ senescence during development.