• Journal of the Korean Institute of Gas
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• v.17 no.2
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• pp.85-89
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• 2013

The purpose of the development of KC-1 LNG cargo containment system is reduction in royalty and increase in competitiveness of shipbuilding industry. An assessment of structure safety for LNG cargo containment system under sloshing load due to ship motion has become an important design element. The ideal way is to implement fully interaction of the fluid domain and the cargo containment system. However the irregular sloshing pressure were idealized in the form of a triangular wave for safety assessment because the fluid- structure interaction analysis is taken the extensive computation time and difficult to ensure the accuracy of the results. In this study, the sloshing load was assumed to be a triangular wave with a maximum pressure of 10 bar during 15/1000 seconds. In the analytic results, the basic insulation panel of KC-1 LNG cargo containment system was assessed to be structurally safe for sloshing load.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.11a
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• pp.1453-1469
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• 2017

우리나라는 후발주자임에도 불구하고 개방형 운영체제의 전격적 채택과 고급 기종 중심의 공격적 제품 라인 확대, 그리고 가치사슬의 수직 통합 체계 구축 등에 힘입어 2011년 세계 스마트폰 시장 점유율 1위를 차지하였다. 그러나 우리나라 스마트폰 산업은 시장 점유율 1위를 달성한지 4년만인 2015년 또 다른 후발주자인 중국에 추격을 허용하였다. 이와 같은 스마트폰 산업 주도권 이전 현상을 논의하기 위해 본 연구는 추격 사이클 이론에 기반하여 중국 스마트폰 산업의 추격과 관련한 기술 수요적 정책 및 제도적 기회의 창을 고찰하고, 이에 대한 중국의 전략적 대응과 우리나라의 실책을 논의하였다. 먼저 기술적 기회의 창으로 스마트폰 아키텍처의 모듈화와 시스템 반도체의 원칩화는 스마트폰 생산에 필요한 기술적 지식의 장벽을 낮추는데 기여하였다. 또한 2013년부터 급성장하기 시작한 저가(190달러 이하) 스마트폰 시장은 기술적 열위인 중국의 시장 개척에 우호적 기회로 작용하였다. 이와 함께 중국 정부의 스마트폰 관련 연구개발 투자 확대는 중국에게 우호적 사업 환경을 제공하는 정책적 기회의 창으로 작용하였다. 이와 같은 기회의 창을 활용하기 위해 중국 스마트폰 산업은 빠른 시장 진입, 원가 절감을 위한 현지 부품 채용, 정부 연구개발 투자를 활용한 기술 역량 축적 등의 전략적 대응을 전개하였다. 반면 우리나라는 고급 기종 생산 고수와 저가 기종 출시 지연, 수직통합 체계의 고착화에 따른 부품 경쟁력 악화에 따라 중국에 추격을 허용하게 되었다. 본 연구는 산업 주도권 이전 현상에 대한 최신 실증을 추가함으로써 추격 사이클 이론의 발전에 기여할 것으로 기대되며, 향후 우리나라 스마트폰 산업 발전 정책 발굴에 중요한 지침으로 활용될 것으로 기대된다.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.9
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• pp.9-17
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• 1999

In this paper, we present a mathematical modeling and perform a performance analysis of double-dwell serial search algorithm, which has a search window concept, for pilot channel in DS-CDMA(Direct Sequence Code Division Multiple Access). We derive a code detection function, a false alarm function, a code miss function, and a mean code acquisition time for the performance analysis. We calculate the mean code acquisition time of the mathematical model in IS-95 forward link and compare it with that of the conventional search methods. The performance of the code acquisition system is also evaluated to investigate the effect of dwell times and search window size. The JTC channel model, which is a PCS channel model in North America, is used for the analysis. The numerical result shows that the mean code acquisition time of the double-dwell serial search algorithm with a search window is reduced by about 17%~25% than those of the conventional ones.

• Journal of The Korean Association For Science Education
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• v.32 no.7
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• pp.1169-1186
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• 2012

The purpose of this study was to investigate the direction of science gifted education based on creativity and character by perception in the gifted education field. Data was collected by in-depth interviews with nine teachers, 10 science gifted students, and their parents, individually or in groups. The results of the study showed that the participants perceived character, creativity, leadership and morality as the important capabilities to have in the future society. Also, they wanted to explore science as much as they wished, form values as a leader, and feel a sense of accomplishment through a collaborative research project. The study suggested that it needed to construct cooperative learning and self-directed scientific investigation for science gifted education based on creativity and character.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.372-378
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• 2012

Xanthium sibiricum using extracts antioxidant activity and antimicrobial activity were analyzed and the following results were obtained. Antioxidant activity using DPPH as a VLC column fractionation experiments XS-5 (water fraction of Xanthium sibiricum) concentration in the 500 ${\mu}g/ml$ to 87.53 percent in the highest antioxidant activity was found, VLC fractionation in XS-3-2 (eluted with chloroform/methanol 7~10%) concentration of 500 ${\mu}g/ml$, showed the antioxidant activity of 78.72%. The antioxidant activity measured by PCL XS-1 (n-hexane fraction of Xanthium sibiricum) XS-5 (water fraction of Xanthium sibiricum) and 13.32 nmol open column XS-3-2 (eluted with chloroform/methanol 7~10%) showed antioxidant activity with 14.34 nmol. The antimicrobial activity against Candida albicans XS-2 (methlene chloride fraction fo Xanthium sibiricum) is the concentration of 500 ${\mu}g$/disc 1 mm of the clean zone was formed. XS-3 (ethanol fraction fo Xanthium sibiricum) in the antioxidant activity using DPPH and PCL had higher antibacterial activity was low.

• Tunnel and Underground Space
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• v.29 no.2
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• pp.89-107
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• 2019

Rock joints have an extremely important role in analyzing the mechanical stability and hydraulic characteristics of rock mass structures. Most rock joint parameters are generally indicated as a distribution by statistical techniques. In this research, calculation technique of Joint Center Volume (JCV) is analyzed, which is required for estimating the size distribution having the largest uncertainty among the joint parameters, then a new technique is proposed which is applicable regardless of the shape of survey window. The existing theoretical JCV calculation technique can be applied only to the plane window, and the complete enumeration techniques show the limitations in joint trace type and analysis time. This research aims to overcome the limitations in survey window shape and joint trace type through calculating JCV by using Monte Carlo simulation. The applicability of proposed technique is validated through the estimation results at non-planar survey windows such as curved surface and tunnel surface.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.303-315
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• 2018

Bonsai is part of export forest products in Korea. Demand for bonsai exports to other countries is growing but the need for quarantine hazards must be eliminated in other to export. Plant parasitic nematode is also an important factor in quarantine. The nematodes were surveyed from bonsai farms in 6 areas of Korea. The surveyed deciduous bonsai plants were Acer palmatum, Zinnia elegans, Ligustrum obtusiflium, Carpinus turcaninowii, and Malus sieboldii. Three plant parasitic nematodes (Hemicyliophora koreana, Rotylenchus blothrotylus and Xiphinema americanum) and three non-parasitic nematodes (Aporclaimellus donghwaens, Egtitus andhricus, and Mesodorylaimus usitatus) were isolated from bonsai. Non-parasitic nematode, Mesodorylaimus usitatus was isolated from all surveyed bonsai trees. Only two species of quarantine nematodes (Hemcylicopora koreana and Xiphinema americanum) were found from bonsai. A. donghwaens and M. usitatus were isolated from root of bonsai tree. However other nematodes were isolated from soil in bonsai trees.

• Communications of Mathematical Education
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• v.32 no.4
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• pp.477-493
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• 2018

The six core competencies included in the mathematics curriculum Revised in 2015 are problem solving, reasoning, communication, attitude and practice, creativity and convergence, information processing. In particular, the creativity and convergence competency is very important for students' enhancing much higher mathematical thinking. Based on the creativity and convergence competency, this study selected the five elements of the creativity and convergence competency such as productive thinking element, creative thinking element, the element of solving problems in diverse ways, and mathematical connection element, non-mathematical connection element. And also this study selected the content(chapter) of the graph in the seventh grade mathematics textbook. By the subject of the ten kinds of textbook, this study examined how the five elements of the creativity and convergence competency were shown in each textbook.

• Journal of the Korea Society of Computer and Information
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• v.27 no.6
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• pp.181-188
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• 2022

This study analyzed the effectiveness of sharing activities through software creative sharing classes. The purpose is to find a way for related activities to be carried out continuously. For this study, pre and post were test on changes in self-esteem, responsibility, and sense of community targeting 25 university students in Chungnam. The collected data were analyzed with SPSS 24. The results derived from this study are as follows. First, the self-esteem was significantly higher after the software creative sharing class than before. Second, the responsibility was significantly higher after the software creative sharing class compared to the prior. Third, the sense of community was found to be significantly higher after the software creative sharing class than before. Therefore, it was found that the software creative sharing class had a positive effect on self-esteem responsibility and sense of community. Based on these data, a method to expand continuous participation in talent sharing was suggested.

• Journal of The Korean Association For Science Education
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• v.32 no.1
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• pp.113-128
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• 2012

This study explored to what extent Korean science teachers perceived socioscientific issues (SSI) as an effective instructional tool for creativity and character (CreActer) education; which was recently announced as a main goal for the Korean National Science Curriculum 2009. The guiding research questions were as follows. (1)How do science teachers conceptualize the relationship between creativity and character in the context of science classes? (2) What do science teachers think about the possibility of CreActer education through SSI in science classrooms? Thirty science teachers participated in individual interviews (each lasted 20-90 minutes). In the results, the teachers' perceptions on CreActer education and SSI for CreActer education were categorized into four profiles. Eleven teachers in Profile A thought that creativity was positively correlated with character education because their understanding of creativity and character embraced a very broad range of elements. They mentioned that addressing SSI in the science classes would be satisfactory to cover those elements of CreActer education. Six teachers in Profile B mentioned similar elements of creativity and character of Profile A, but reported that, in their experience, creativity was often inversely correlated with character. However, they responded that addressing SSI would be a good way to integrate creativity and character in the science classes. Ten teachers in Profile C believed there was no relationship between creativity and character, but took a positive stance on CreActer education through SSI. Unlike Profile A and Profile B, they tended to regard character as only an interpersonal virtue. And three teachers in Profile D had a narrow perspective on CreActer education. Not only did they think creativity had no relationship with character, but also disagreed that CreActer education would be activated by addressing SSI in science classrooms. The results imply that SSI could be used as an effective instructional tool for CreActer education, but this can be possible when science teachers expand their view on CreActer education.