• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.43-43
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• 2003

본 연구에서는 정지궤도 위성을 이용한 표준시각 동기 서비스에 실시간 궤도결정 기술을 적용하는 방안을 고려하였다. 정지궤도 위성을 이용하여 표준시각 동기신호를 전파하는 연구는 여러 나라에서 진행되고 있는데 3지역에서의 측정(Trilateration)과 미분 보정(Differential Correction) 방식이 일반적인 방법으로 채택되고 있다. 본 논고에서는 한국 항공우주연구원에서 진행 중인 표준시각 동기 서비스 연구와 이를 위해 제작중인 실시간 궤도결정 기술을 적용한 실험 소프트웨어에 대해 소개하고자 한다. 실시간 궤도결정 방법을 적용하게 되면 동기신호 전파에 있어서 가장 큰 오차의 원인이 되는 위성궤도 예측 오차를 크게 줄일 수 있을 것으로 판단된다. 본 연구에서는 기존에 궤도 결정을 위해 사용하는 톤 레인징에 의한 위상차 신호와 안테나 각도 대신에 동기신호 자체만을 사용하고 있으며 1개의 수신 데이터만으로 궤도 결정을 수행하는 방안을 강구하였다. 본 논고에서는 실시간 궤도 결정에 의한 시뮬레이션 결과와 한국항공우주연구원에서 준비 중인 실험에 대해서 간략히 소개한다. 그리고 본 연구에서 개발된 기술은 2004년 4월에 무궁화위성 2호를 이용하여 실험을 수행할 예정이다.

• Journal of The Korean Association For Science Education
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• v.39 no.6
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• pp.799-807
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• 2019

The study was conducted to identify if the first-year program of science-focused school improved students' scientific core competency and science learning motivation. The first-year program of the science-focused school consisted of basic education in scientific inquiry, investigation, advanced experiment, and basic education in small research. There were a total of 262 participants in the program, and 169 students took three survey tests. Through the analysis of a group-based trajectory modeling, students were differentiated based on similarity of score changes. This study showed that the first-year program of the science-focused school significantly improved students' scientific core competency and science learning motivation. A group-based trajectory modeling found that about 40~60% of students saw the effects of the program. The students who chose the humanity track showed effects, while some students who chose the science-focused track did not show effects. A group-based trajectory modeling showed the methodological effects of identifying the change process of individual students. This study identified the positive effects of science-focused school policy statistically and is a meaningful example for analyzing the effectiveness of science-focused school programs.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.7
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• pp.356-371
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• 2001

본 논문에서는 비동기식 상위수준합성기 제작의 일환으로 효율적인 비동기식 제어부의 자동생성에 관한 방법을 제안한다. 제안된 방법은 목적시스템의 사양으로써 주어진 제어데이터흐름그래프로부터 일련의 체계적인 변환과정을 통하여, 제어부를 구성할 제어회로들에 대응하는 계층적으로 분할된 비동기식 유한상태기들의 집합을 유도한다. 유도된 비동기식 유한상태기들은 현존하는 비동기식 제어회로 합성기를 통하여 해저드 없는 비동기식 제어회로들로 합성되며, 이들은 상호간에 4단계 핸드셰이킹에 기반한 신호교환을 통하여 동작하면서 전체 시스템을 제어하는 계층적으로 분할된 비동기식 제어부를 구성한다. 획득한 제어부는 계층.분산적이며, 면적, 성능 및 합성시간의 측면에서 기존방식을 통하여 생성한 제어부에 비해 우월하다.

• Journal of the Korean Society of Earth Science Education
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• v.10 no.3
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• pp.278-289
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• 2017

The purpose of this study is to investigate the effect of science writing heuristic class on 'seasonal change' on elementary school students' science learning motivation and scientific attitude. In order to carry out this study, 49 students from 6 grade of elementary school in P metropolitan city were selected and 24 students in one class were selected as experimental group and 25 students in the other class were selected as the comparative group. The experimental group was taught science writing heuristic in 10 times classes related to the 'seasonal change' and the general classes related to the 'seasonal change' were conducted in the comparative group. Based on the results of this study, the conclusions are as follows. First, the science writing heuristic class about 'seasonal change' showed a significant effect on elementary school students' science learning motivation for science class. This is analyzed as a result of the students being more familiar with their science class through science writing heuristic class. Second, the science writing heuristic class about 'seasonal changes' showed a significant effect on elementary school students' scientific attitude. This is because the science writing heuristic class offered elementary school students an opportunity to combine their experiences in daily life with the contents of the class. Third, students' participation, satisfaction, and interest in the science writing heuristic class applied in this study were high. Therefore, it seems to be effective if the science writing heuristic class is used for science class for elementary school students.

• Journal of the Korean earth science society
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• v.27 no.3
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• pp.260-268
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• 2006

Students' affective attitude not only influences their achievement in a meaningful way but is also an important educational goal in its own right. This research investigated how students' interest in science varies among elementary, middle, and high-school students based on surveys and reviews of previous research results. We analyzed students learning attitude in terms of (1) interest in and enjoyment of science, (2) instrumental motivation in science, (3) science learning anxiety, and (4) self-concept in science. Major findings are that students showed more negative attitudes in intrinsic motivation, instrumental motivation, value perception of science, and confidence in science as they move in to a higher school level. According to the students' explanation, science classes get boring in higher grades because of difficult contents, lack of experiments and activities, and the teachers' monotonous explanations. Based on the results, recommendations on how to improve students' attitudes towards science are suggested. First of all, we need to secure more science instructional hours in the school curriculum than the 7th national curriculum to implement improved science teaching and learning methods.

• Journal of the Korean earth science society
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• v.26 no.3
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• pp.175-182
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• 2005

The purpose of this study was to investigate the effects of STS (Science, Technology and Society) instruction on 5th graders learning motivation and scientific attitudes, using ARCS (Attention, Relevance, Confidence, Satisfaction) strategies. A total of 53 fifth grade students were sampled from an elementary school, and were assigned to the experimental and the control groups. For four weeks, the experimental group was treated with STS instruction using ARCS strategies while the control group was treated with traditional instruction. The result of this study showed that STS instruction using ARCS strategies was more effective in the development of students' learning motivation and scientific attitudes.

• Journal of The Korean Association For Science Education
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• v.28 no.6
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• pp.527-545
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• 2008

This paper suggested a 4E&E Learning Cycle Model using learning motivation for students in science education. The model has been developed on the basis of motivational and instructional design. The 4E&E Learning Cycle Model has four phases such as engage, explore, explain and expand, and two subsidiary phases such as evaluate, and feedback provided with at each phase. The model has gone a process of instruction with learning effects evaluation and providing feedback in science classroom, which facilitate to increase the effectiveness of learning activities. Especially, the 4E&E Learning Cycle Model using motivational learning strategies makes the learners be attractive to and immersed in instruction. This model has potentials in educating students in science education.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.113-121
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• 2012

A total of 150,624 records of Holstein milk production collected from 2005 to 2009 were analyzed to investigate the effects of two different contemporary group definitions, parity and somatic cell score (SCS). The first definition (H BY S) of contemporary group was milking cows and heifers born in the same year and season. And the second thing (H CY S) was milking cow and heifers that delivered calves in the same year and season. Effects of contemporary group, parity and regression effect on SCS from two models were highly significant sources of variation. Coverage of variation ($R^2$) was somewhat higher in models with H BY S as contemporary group. From multivariate models with H BY S, phenotypic correlation coefficients of milk components were estimated high and positive. However, the phenotypic correlation coefficient between milk yield and SCS was -0.09, which was low enough to evidence no correlation between them. Phenotypic correlation between SCS and butter fat or between SCS and protein were also negligible but negative. From multivariate models with H CY S as contemporary group, phenotypic correlation among milk traits and SCS were similar to the estimates from models with H BY S. However, SCS in these models were lowly but negatively correlated with milk yield, milk protein, butter fat or SNF, and the phenotypic correlation coefficients of which were -0.10, -0.08, -0.08, -0.11, respectively.

• Journal of The Korean Association For Science Education
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• v.21 no.1
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• pp.59-75
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• 2001

While previous studies have recognized and have researched the resistance of students' scientific conception to change and the difficulty of the change of a conception's status, few have investigated the idea of conceptual ecology as a context of conceptual change learning, including the role that affective and motivational aspects might play when students are exposed to conceptual change learning, The present study was conducted to describe in detail high school students' views about learning and knowing science by summarizing of students' conceptual ecologies. The study was interpretive, using multiple data sources to achieve a triangulation of data. Three students from a public high school for boys serve as cases representative of students' views about learning and knowing science. Students' enthusiasm to pursue science was closely connected to their views about learning and knowing science. Students' views about learning and knowing science are influenced by their views regarding science and science class including the nature of knowledge, learning, and their epistemological commitments, They influence students' self-efficacy and motivation on learning science.

• Science & Technology Policy
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• v.6 no.2 s.83
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• pp.45-54
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• 1996