• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.604-607
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• 2003

This study investigates the micro-cutting of cemented carbides using PCD(polycrystalline diamond) and PCBN(polycrystalline cubic boron nitride) cutting tools are performed with SEM direct observation method. The purpose of this study is to make clear the cutting mechanism of cemented carbides and the fracture of WC particles at the plastic deformation zone in orthogonal micro-cutting. And also to achieve systematic understanding, the effect of machining parameter on chip formation and machined surface was investigated, including cutting speed. depth of cut and various tool rake angle.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 추계학술발표회논문집(1)
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• pp.224-229
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• 1996

An experimental study on critical heat flux (CHF) and two-phase flow visualization has been performed for water flow in internally-heated, vertical, concentric annuli under near atmospheric pressure. Tests have been done under stable forced- circulation, upward and downward flow conditions with three test sections of relatively large gap widths (heated length = 0.6 m. inner diameter = 19 mm, outer diameter = 29, 35 and 51 mm). The outer wall of the test section was made up of the transparent Pyrex tube to allow the observation of flow patterns near the CHF occurrence. The CHF mechanism was changed in the order of flooding, chum-to-annular flow transition, and local dryout under a large bubble in churn flow as the flow rate was increased from zero to higher values. Observed parametric trends are consistent with the previous understanding except that the CHF for downward flow is considerably lower than that for upward flow.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1638-1642
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• 2008

Cell migration is one of the essential mechanisms responsible for complex biological processes. Intensive researches have begun to elucidate the mechanisms and search intriguing conditions for efficient control of cell migration. One general mechanism which is widely applicable for cells including neutrophil, Escherichia coli and endothelial cell is chemotaxis. Especially, understanding the chemotactic mechanics of cell crawling has important implications for various medical and biological applications. The single cell study for chemotaxis has an advantage over studies with the population of cells in providing a clearer observation of cell migration, which leads to more accurate assessments of chemotaxis. In this paper, we propose a three-dimensional model considering a single crawling cell to study its chemotaxis. The semi-implicit Fourier spectral method is applied for high efficiency and numerical stability. The simulation results reveal rich dynamics of cell.

• 아동학회지
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• 제26권4호
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• pp.293-302
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• 2005

This study investigated behavior characteristics for the gifted(N=210) and the high achievers(N=1l5). The participations in this study were 200 teachers who rated their 325 students' behavior characteristics in 25 public elementary schools in U.S.A rating of behavior characteristics in learning style, motivation, creativity, and leaderships by teachers indicated differences in keen observation, rapid insight into cause-effect relationship, a large storehouse of information, language fluency, absorption/task persistent, preference for own learning activities, concerns for moral/ethical issues, and a diversity of interests between groups. No differences in understanding of underlying principles, organization, curiosity, creativeness, motivation, initiating activities in areas of personal interest, directing group activities, and intellectual playfulness/imagination were found in addition to some differences between two groups.

• 영재교육연구
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• 제20권3호
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• pp.655-679
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• 2010

본 연구는 수학영재교육 담당교사의 교수학습 전문성 향상을 위해 수학영재 수업 사례를 주로 Flanders 언어 상호작용 분석법과 TIMSS 비디오 분석법을 이용하여 분석하고 이를 통해 수학영재 수업을 어떻게 해야 하는 것인가에 대한 시사점을 주고자 시작되었다. 본 연구를 통하여 수학영재교육 담당교사의 영재수업 질적 제고 방안에 대한 심층적인 이해와 반성적 성찰의 계기가 되어 더 나은 교사로서의 삶을 계획하고 영재수업 전문가로서 발돋움하는 기회가 되었으면 한다.

• 한국초등과학교육학회지:초등과학교육
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• 제31권4호
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• pp.532-540
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• 2012

The purpose of this study was to examine the effect of utilization of drawing skills in elementary science class on improving scientific drawing. The learning program has been developed for 5th grade students in the regular classes in order to enhance scientific drawing skills. The program was composed of three steps, understanding the kinds of drawing, imitating sample drawing, representing through observation. The developed program was verified by the science education scholars and teachers. Students trained during 3 hours with scientific drawing skills step by step. As a result, students significantly improved skills in scientific drawing skills. Furthermore, the effect was sustained after a month. On the other hand, there were no statistically meaningful differences on scientific attitudes and preferences.

• 유통과학연구
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• 제16권12호
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• pp.33-45
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• 2018

Purpose - This study analyzes how Hanssem, which ranks first in domestic market in the furniture industry, responds to the expansion of IKEA, a large overseas furniture maker, and investigates the recent strategic changes of Hanssem and IKEA. Research design, data, and methodology - As a research method, a general method of case studies, literature research, is carried out through academic research results, reports, articles, and statistics. In addition, methods such as field observation and interview with stakeholder were performed to collect in-depth understanding and information about the companies. Results - Along with its core competences, Hanssem has pursued strategic changes to compensate for its weaknesses. IKEA has also used a variety of strategies changes to match the situation in Korea. Conclusion - Both companies have properly balanced localization elements and standardization strategies that value the needs of local consumers. In particular, Hanssem has implemented various strategies based on its core competence in response to IKEA's strategy. In addition, Hanssem and IKEA are actively managing and have good performance not only in Korea but also in foreign markets.

• 대한가정학회지
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• 제43권9호
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• pp.15-26
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• 2005

The purpose of this study was to develop an educational program that enhances a single mother's social adaptation (self-esteem and sociality) based on the precedent studies. The subjects of this program were seven single motherswholive in C city in Chung Cheong Namdo. Paired-Sample t-test, individual change and group processing description data, and behavior observation record data were analyzed. Research results are as follows based on the research questions. First, a group of 8 single mothers who participated in the program showed an improvement of their social adaptation. Therefore, the effectiveness of the educational program was verified. Second, as the group session went on, the cohesion among the group members was solidified and their will to participate in the program was increased. Third, generally, individuals' understanding, acceptance, and adaptation toward themselves and others were enhanced. On the whole, the educational program for improving single mother's social adaptation was verified. We need to develop and implement more programs that enhance single mother's social adaptation in the future.

• 한국과학교육학회지
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• 제10권2호
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• pp.55-66
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• 1990

This study aimed at identifying the characteristics of current Earth Science Curricula in several countries in terms of their format, objectives and contents and discussing about them. The curricula(including textbooks) were collected from 6 countries The United States of America, England, Australia, Japan and The Republic of China. Here are the results of this study ; 1. Earth Science should be teached in high school and assigned at least 8-10 unit. 2. In Earth Science objectives, scientific inquiry methods through observation and experiment and mutual relationship among science, technology and society must be stressed. 3. The contents of Earth Science must did with experimental and activity rather than understanding in order to induce students to how more intersts in Earth Science. 4. There is a growing tendency for Earth Science Education to be attached importance to life environment and career education.

• 천문학논총
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• 제19권1호
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• pp.65-70
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• 2004

An imaging spectrograph concept optimized for extended far-ultraviolet emission sources is presented. Although the design was originally developed for FIMS aboard the first Korean science satellite STSAT-l launched on September 27, 2003, no rigorous theoretical background of the spectrograph design has been published. The spectrograph design employs an off-axis parabolic cylinder mirror in front of a slit that guides lights to a diffraction grating. The concave grating provides moderate spatial resolution over a large field of view. This mapping capability is absent in most astronomical instruments but is crucial to the understanding of the nature of a variety of astrophysical phenomena. The aberration theory presented in this paper can be extended to holographic gratings in order to improve the spatial as well as the spectral resolutions.