• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.73-82
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• 2011

The term 'green' has become an important way of survival for the construction industry in 21th century in accordance with the emergence of the environmental crisis due to the climatic change. Especially the policy of carbon taxation, planed to be introduced from 2012, is expected to be a considerable burden to the construction industry which has abundant carbon emission during the resource transportation due to the complexity of resources and local distribution of the construction sites. In this regard, this study shows an optimizing strategy for delivery frequency, which downsizes the net distribution costs based on the assumption that, despite of its other advantagements, the frequent small lot mode of JIT delivery would take negative effects due to the increase of costs of transportation and carbon emission once the carbon taxation policy carried out. To simulate the efficiency of the management strategies, the System Dynamics modeling has been used. The results show that the frequent small lot transportation strategy is now always efficient method to these changes, and that the frequency of transportation should be re-determinated according to the extent of the imposition of carbon tax. This study provides the conceptual frame for an efficient management of transportation system of the construction industry, showing necessity of change of the resource transportation systems through analysing JIT deliver system in accordance with the global changes in environmental economy.

• Journal of Science Education
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• v.38 no.3
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• pp.569-584
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• 2014

The Purpose of this study was an analysis of high school student's understanding level about concepts of special relativity through in-depth interview. The 8 participants were 10th grade students in H high school in Ulsan city, who were interviewed and analyzed in the results of the interview about basic concepts of special relativity using achievement checklist in 6 situations(principle of constancy of light velocity, principle of relativity, relativity of simultaneity, garage paradox, rocket paradox). As results of the checklist, the participants showed high achievement in the content level of simple phenomena and simple concepts related to special relativity. But they showed low achievement in the concept level for fundamental understanding of special relativity. As results of the interview, it was found that the participants decided the order of events depending on their intuition and had a difficulty to apply the coordinate system to real situation, even though they mathematically understood it. In addition, some participants who could not understand the inertial coordinate system explained paradoxes of relativity depending on their intuition and had learner's chaos. Finally, though high school students usually being in formal operational stage, some students had difficulty to draw phenomena of space and time in two dimensional plane.

• Journal of the Korean School Mathematics Society
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• v.16 no.2
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• pp.383-407
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• 2013

As an alternative of making students active and independent under the passive learning conditions in school math classes, many researchers have paid much attention to problem posing and done a lot of research on it. Above all, Brown and Walter proposed What I f Not strategy as a means of problem posing. In this strategy, during the process of posing problems, the transformation of their attributes is inevitably made, and so after problem posing, the process is finished by explaining the problem. But only the simple transformation of attributes could pose wrong problems. It suggests that it is very important to recognize the relationship which leads to organic connection between attributes in order to pose the right problem. However, many other studies of problem posing haven't focused on this fact. Thus, this study tried to design a model of problem posing to help recognize inherent knowledge in the problem and then pose the right problem by adding an activity of meaning analysis. We concretely showed a model of problem posing emphasizing the analysis of meaning by means of an example, thereby examining the meaning of the model. This study expects students to have the chance to understand the true meaning of problem posing and to be active learners after all.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.483-496
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• 2018

NCS (National Competency Standards) has emerged as an issue of great importance amongst Korean universities and corporations. Although previously used mostly for vocational education purposes at colleges, NCS is currently receiving an increasing amount of attention from 4-year universities as well. In the ever-evolving information economy, the basic workplace skills defined by NCS, which include soft skills such as communication skills, problem-solving skills, and interpersonal skills, have now become more important than specific technical skills. This study analyzes the correlation between the basic workplace skills of NCS with participation in Formula SAE activities, a common component of Capstone design courses across North America and Europe. Data are derived from site visits to Formula SAE competitions, competition-related documents drafted by student participants, and questionnaires administered to student participants at the Formula SAE Lincoln completion and at the Korea KSAE competition. From the study findings, we claim that the basic workplace skills of NCS are closely correlated to participation in Formula SAE activities. Through a survey designed to measure the degree to which Formula SAE activities can enhance an individual's NCS Basic Workplace Skills, we find that these activities overall improved NCS basic workplace skills averaging 4.0 points above in the Likert 5-point scale. For reference the mathematical skills, communication skills, and problem-solving skills displayed statistically significantly correlation with NCS but the remaining 7 skills did not show a statistically strong correlation with NCS comparatively.

• Journal of The Korean Association For Science Education
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• v.33 no.4
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• pp.708-717
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• 2013

The new paradigm of the 21st Century science education explores a wide range of possibilities that can foster students' interest toward science and creative convergence thinking. In this study, through the analysis of programs that were developed in 'STEAM leader school' and 'STEAM teacher association for research' supported by the 'Ministry of Education, Science, and Technology,' we analyzed the linking frequency with each of STEAM education's fields and teachers' perception for the convergence strategy of technology and engineering. The results of this study show that linking frequency of technology and engineering is lower than the field of arts and mathematics in elementary school, but higher in middle and high school. 'Introduction technology contents in lives' in technology and 'crafts activity' in engineering are the most used teaching and learning strategy in STEAM education. But, although 'crafts activity' is engineering's major way of learning, many teachers understand and use it as a technological teaching learning strategy. It is important to understand that each of STEAM education's field has a unique nature and educational implications, for the effective settlement of STEAM education, we need to consider teaching and learning strategy in various way.

• Journal of Educational Research in Mathematics
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• v.26 no.3
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• pp.333-354
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• 2016

The aim of the present study is twofold. One is to confirm a hypothesis that a student's rate concept influences her conceiving change of a function in the view of rate of change and the other is to build up foundations for understanding the transition process from her rate concept to the concept of rate of change when she investigates the change of concentration as an intensive quantity. We explored how three participating high school students recognized and expressed change of given functions by using their rate concept as a conceptual tool. The result indicates that a change in students' rate concept might have an effect on understanding how function values change in term of rate of change. We also expect that it could be a catalyst for further research for clarifying the relationship between students' rate concept and their development of a concept of rate of change as a foundation for learning calculus.

• Communications of Mathematical Education
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• v.35 no.2
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• pp.153-172
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• 2021

Various competencies such as critical thinking, systems thinking, problem solving competence, communication skill, and data literacy are likely to be required in the 4th industrial revolution. The competency regarding data literacy is one of those competencies. To nurture citizens who will live in the future, it is timely to consider research on teacher education for supporting teachers' development of statistical thinking as well as statistical knowledge. Therefore, in this study we developed and implemented a data analysis project for pre-service teachers to understand their changes in statistical knowledge in addition to their experiences of data-driven decision making process that required them utilizing their statistical thinking. We used a mixed method (i.e., sequential explanatory design) research to analyze the quantitative and qualitative data collected. The findings indicated that pre-service teachers have low knowledge level of their understanding on the relationship between population means and sample means, and estimation of the population mean and its interpretation. When it comes to the data-driven decision making process, we found that the pre-service teachers' experiences varied even when they worked as a small group for the project. We end this paper by presenting implications of the study for the fields of teacher education and statistics education.

• Journal of Korean Elementary Science Education
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• v.25 no.2
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• pp.118-125
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• 2006

The purpose of the study was to research science gifted students' learning styles and perceptions on subject matter content. The data was collected from primary science and mathematics classes of a University Center for Science Gifted Education, science classes of a Metrocity Primary Gifted Education Institute, and classes of a normal school. The results of the study were that gifted students perceived the school curriculum much easier than non-gifted students did, ($X^2(4)=33.180$, p<.001), and that levels of interest in the content did not differ between the groups, but 34.6 percent of the total students responded that they found the content uninteresting. Gifted students did not see the content as being important compared to the non-gifted students, ($X^2(4)=12.443$, p<.05), and gifted students valued the methods used higher than the actual content of the textbook. The most helpful activities for their teaming that gifted students chose were projects, listening to teachers, and conducting experiments, amongst others. They also preformed 'teaming at their own speed in a mixed group'" for the study of social studies, science, and mathematics, whereas non-gifted students preformed teaming at the same speed. The two groups of science gifted students varied especially in their perceptions of most helpful activities. It is suggested that special programs for fulfilling gifted students' needs and abilities need to be developed and implemented.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.5
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• pp.62-72
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• 1995

공학분야에 널리 사용되고 있는 신뢰도 분석 방법 중에서 Monte Carlo simulation (MC), Mean-value First-Order Second-Moment Method(MFOSM), and Advanced First-Order Second-Moment(AFOSM) method들을 강물의 오염물질 농도와 수질기준치사이의 신뢰도 분석에 적용하였다. 미 환경 보건국에서 개발 보급한 QUAL2E를 이용하여 Mew Jersey에 위치한 Passaic강의 수질예측에서 4가지 주요인자(용존산소, 생물학적 산소요구량, 암모니아 그리고 조류)들이 정해진 수질기준치를 유지 할 수 있는 확률을 세가지 방법에 의해 추정한 후에 상호 비교하였다. MC방법에 의해 2,000회 simulation시켜서 그 결과가 시스템의 추계학적 성질을 잘 반영한 것으로 판단하여 비교기준으로 삼고 MFOSM과 AFOSM에 의해 추정한 결과와 비교하였다. MFOSM의 결과보다는 AFOSM의 결과가 전체적으로 MC의 결과에 더 근접하였으며, 이유는 AFOSM의 계산방법이 MFOSM의 선형근사로 인한 오차를 줄일 수 있었기 때문인 것으로 판단된다. MC방법의 결과와 다른 방법들의 결과사이의 차이가 입력 변수들이 평균값에서 멀어질 때가 많았는데 이는 MC의 경우 입력 변수들이 일정범위를 벗어나서 비현실적인 상황이면 model이 정지하는데, 다른 방법들은 simulation에 의한 것이 아니고 수학적인 계산에 의해서 신뢰도가 추정되기 때문에 이러한 상황이 반영될 수 없기 때문이다. 강물의 수질을 취급하는 공학적인 측면에서 보면, 이중에 가장 간편한 MFOSM이 많은 simulation이 필요한 MC나 계산방법이 상대적으로 복잡한 AFOSM에 비해 오차가 크지 않아서 이들을 대시하여 사용될 수 있다고 판단된다. 유래의 PAF가 분비된다는 것을 알 수 있었으며, 이러한 인자는 동결처리에서도 그 기능은 전혀 변하지 않는다고 본다. 이후에 있어서 mouse LIF의 첨가는 돼지의 수정란을 배반포 이후의 단계에까지 발달시킬 수 있었다. 있어서 더 적합한 것으로 판단되었다. 5. 개발된 모형은 논 관개의 물리적 측면과 관리목표 모두를 고려한 것으로 계산된 효율은 벼, 생육 각 단계에서의 효율 비교에 양호한 방법임을 알 수 있다.은 Sharpsburg 점질양토에 대한 S.C.S 한계허용치 10ton/ha/year 이내로 나타났다. 비처리구에서의 토양유실량은 평균 2.56ton/ha/year로 높게 나타난 반면 3개의 서로 다른 추리구인 비수구, 초생수로구 및 Bromegrass구에서는 각각 0.152, 0.192 및 0.290ton/ha/year로 낮은 결과를 가져왔다. 6. 평균 침전량에 대한 L.S.D. 검정 걸과 전시험구중 비처리구가 고도의 유의차를 나타낸 반면 비수구, 초생수로구 및 Bromegrass 목초구 간에는 아무런 유의차가 인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가

• Journal of The Korean Association of Information Education
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• v.19 no.2
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• pp.159-166
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• 2015

STEAM is a multidisciplinary education program which intended to promote creative thinking by combining studies in the arts and STEM(Science, Technology, Engineer, Mathematics) fields. STEAM education can bring out creativities in students through educational activities of integrating and combining diverse studies. In this research, we integrated the educational elements of science, technology, engineering, mathematics, and arts using robots and then developed an educational program that raises the creative and character (focused on collaboration and communication) of students in a more fun and effective way. Using our developed educational program, we taught 6th grade students of an elementary school located in Seoul. As the result, most of students were found to be enhanced in their creativity and character after participating in the STEAM-based programming education course.