• Journal of the Korean Magnetics Society
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• v.23 no.2
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• pp.68-76
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• 2013

Currently, wireless power transmission technology based on magnetic induction was employed in battery charger for smart phone application. The system consists of wireless power transmitter in base station and receiver in smart phone. Size and thickness of receiver was strictly limited in the newest smart phone. In order to achieve high efficiency of a tiny small wireless power receiver module, sub-millimeter thick electromagnetic wave shielding sheet having high permeability and Q was essential component. It was found that magnetic field from transmitter to receiver can be intensified by sufficient shielding cause to minimize leakage magnetic flux by those magnetic properties. This leads to high efficiency of wireless power transmission and protects crucial integrated circuit of main board from electromagnetic noise. The important soft magnetic materials were introduced and summarized for the current small-power wireless power charger and NFC application and mid-power home appliance and high-power automotive application in the near future.

• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.22-35
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• 2019

Development of low cost rechargeable batteries has been considered as a significant task for future large-scale energy storage units (i.e. electric vehicles, smart grids). Sodium-ion batteries (SIBs) have been recognized as a promising alternative to replace conventional lithium-ion batteries (LIBs) because of their abundancy and economic benign. Nevertheless, Na ions have larger ionic radius than that of Li ions, resulting in sluggish transport of Na ions in electrodes for cell operation. There have been efforts to seek suitable anode materials for the past years operated based on three different kinds of reaction mechanism (intercalation, alloy reaction, and conversion reaction). In this review, we introduce a class of conversion reaction anode materials for Na-ion batteries, which have been reported.

• Journal of The Korean Association For Science Education
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• v.37 no.5
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• pp.787-797
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• 2017

In this study, we investigated the features of using smart devices in socioscientific issues (SSI) debate classes. Twenty-seven high school students in Gyeonggi-do participated in this study. The processes of the SSI debate classes with smart devices were classified into five stages: data searching, data sharing, summary and organization of data, debate in the classroom, and online debate. Then some features at each stage were identified. It was found that they collected self-directed and in-depth data while reflecting their knowledge and experience, and selected data which were easy to understand at the stage of data searching. The specificity and validity of the evidences gathered and the clarity of the sources were improved at the stage of data sharing, although they shared more data offline than online. They organized their data by using paper rather than smart devices at the stage of summary and organization of data. Most of them failed to use the summary in debate. They argued and refuted based on concrete grounds at the stage of debate in the classroom, which raised students' interest in debate and led students to participate actively. At the stage of online debate, they were able to rearrange and review the arguments of both sides, and the participation of the students who were passive in classroom debate was enhanced. Based on these results, we suggest some effective teaching methods for SSI debate classes using smart devices.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.519-527
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• 2018

The purpose of this convergence study was to examine the effects of smart learning on learner's participation, academic self-efficacy and task value in nursing education. The study was designed using a nonequivalent control group no-synchronized design. The subjects of this study consisted of 86 experimental group and 95 control group who were nursing students. Data were collected from March 2 to June 8. 2018. The data were analyzed using the spss 18.0 program to perform independent t-test. There were not statistically significant differences in learner's participation(t=1.065, p=.288) but were statistically significant differences in academic self-efficacy(t=2.668, p=.008) and task value(t=2.070, p=.040). Therefore, the smart learning was effective in increasing academic self-efficacy and task value for nursing students. The smart learning is expected to be useful as effective teaching and learning strategies in nursing education.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.575-576
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• 2020

본 논문은 근래에 식용곤충 식품에 대한 수요 및 국민적 관심이 증가하여 관련 산업이 급격히 성장하고 있는 가운데, 건강기능성 효과가 널리 알려진 흰점박이꽃무지 유충의 안정적인 생산량 확보를 위한 스마트 사육사를 제작하고 그 성능을 평가한 결과이다. 사육사는 L6m×W3m×H2.8m 크기로 제작하였으며, 안정적인 사육환경을 위하여 사육실과 공조실을 분리하여 설계하였다. 공시재료는 생후 15일이 경과된 흰점박이꽃 무지 유충 1령이며, 스마트 사육사 내 사육환경은 온도 25±2℃, 습도 65±5%로 제어하였다. 사육조사는 매주 1회, 유충의 체중, 길이, 두께를 측정하였으며, 스마트 사육사의 성능평가를 위해 일반 사육농가(전북 소재)와 비교·분석하였다. 사육 4주 후 조사 결과, 스마트 사육사에서 사육한 유충의 체중과 길이는 각각 평균 1.97g/마리와 3.75cm로, 일반농가의 1.58g/마리와 3.55cm에 비해 비교적 높은 것으로 나타났다. 하지만, 두께의 경우 2주 차까지 일반농가에서 대체로 높은 것으로 나타났으며, 이후 3~4주 차에서는 큰 차이를 보이지 않았다. 따라서 본 연구를 통해 개발한 흰점박이꽃무지 유충 스마트 사육사는 일반농가와 비교해 사육이 비교적 빠르고 생산량을 더 많이 확보할 수 있는 시스템으로 농가소득 증대에 유용할 것으로 판단되며, 장소 및 시간에 상관없이 생육환경 제어가 가능하여 개발된 시제품의 보급 확대가 필요하다.

• Science of Emotion and Sensibility
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• v.14 no.2
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• pp.207-220
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• 2011

The purpose of this study is to investigate sensibility words related with eco-friendly in the two media fashion magazines and internet newspapers and to analysis their appearance frequency and changes by the year through 1999~2010. Most frequently used words are 'nature, eco, cotton, natural fiber, health, fresh, clear, preservation, harmony, com fiber, and Lohas'. The words are divided in 4 groups: 'Nature/Environment, Material/Fiber, Human, and Adjectives/Micell'. A point of appearing time is analyzed: 'ecology, memory-shape material, organic, spa' were used before 2000, 'nature environment, eco-friendly, stretch material, wellbeing, substitute, recycling' were in 2000-2001, 'smart material, eco material, green' in 2002-2003, 'coolbiz, Lohas, natural dye' in 2004-2005, 'herb medicine, sustainable, warmbiz' in 2006-2007, 'greensumer, greenlife, solar energy, forest bath' in 2008-2009. Looking into their changes, in early 2000, the words of eco-friendly emotion and sensibility had appeared frequently relatively, but later on they decreased, and again recently increased showing highest appearing frequency. 'Nature/Environment' words have appeared recently very much, while 'Human' sensibility words have not changed much or decreased a little. 'Adjective/Micell' words has increased little bit recently. 'Material/Fiber' words showed decrease at fashion magazine, while they increased at the pages of internet news.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.4
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• pp.433-438
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• 2024

Piezoelectric ceramics play an important role in various electronic applications. However, traditional ceramics are difficult to be used in some complicated structures, due to their low flexibility and high brittleness. To solve this problem, this study prepared and investigated ceramic/polymer composites that can utilize a good flexibility of polymers. Polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) and 0.77(Bi_1/2Na_1/2)TiO₃-0.23SrTiO₃ (BNST23) ceramics were selected to fabricate the composites. Ceramic/polymer composites were prepared using various volume fractions of BNST23 ceramics. The distribution of piezoceramic particles in BNST23/PVDF-TrFE composites was investigated using optical microscopy (OM) and scanning electron microscopy (SEM). The dielectric and piezoelectric properties of the composites were significantly influenced by the volume fraction of the piezoelectric ceramics. As a result, the highest piezoelectric constant (d₃₃) of 56 pC/N was obtained in a composites with 70% volume fraction of BNST23 ceramics. Accordingly, it is expected that BNST23/PVDF-TrFE composites can be applied to various sensor applications.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.01a
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• pp.149-152
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• 2013

이 연구는 스마트교육환경에서의 교육용 앱을 평가하기 위한 신뢰롭고 타당한 도구를 개발하는데 있다. 기존 선행연구에 기초해서 교육용 앱의 평가를 위한 평가모형을 도출했으며, 이 모형은 4개의 평가영역(교수 학습측면, 화면디자인측면, 기술측면, 경제 윤리측면)과 13개 평가요소들로 구성되었다. 이 잠재모형의 통계적 타당성 검증을 위한 자료수집을 하고자, 경기도 소재 중학교 1곳과 고등학교 2곳의 학생 156명을 대상으로 교육용 앱을 평가하는데 있어서 각 평가문항이 갖는 중요도를 평가하였다. 수집된 자료를 탐색적 요인분석한 결과, 교육용 앱을 평가하는 영역으로 교수 학습(흥미성 자기주도성 실용성, 인지발달성), 화면디자인(디자인의 적합성, 어휘의 정확성), 기술(호환성, 안정성), 경제 윤리(경제성, 윤리성) 등 4개 영역이 제안되었다. 또한 문항내적일관성을 확인하고자 신뢰도 분석한 결과, 각 평가영역 별 Cronbach ${\alpha}$는 .88, .85, .82, .80으로 모두 적합한 수준을 보였다. 따라서, 이 연구를 통해 도출된 교육용 앱 평가도구는 통계적으로나 타당성과 신뢰성 측면에서 의미 있는 것으로 판단할 수 있다.

• Smart Media Journal
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• v.6 no.4
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• pp.72-78
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• 2017

The purpose of this study is to enhance the creative activity of youth through coding programs on the subject of Arduino. In order to achieve the purpose of the research, it studies the development of coding education based on Arduino, which is cheaper and generally available for universal use. In addition, in order to verify the program, it applies to the 12 schools in Gwangju Jeonnam and produces the improvements. The results of the study are as follows : first, the coding education program centered on Arduino was developed from a fusion perspective through a procedural model(plan - design - action - evaluation - improvement) and applied to a pilot class. Second, the effectiveness of the student satisfaction survey and the interviews of teachers were analyzed. Third, the improvement of the coding education program is accepted and applied to the next program.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.05a
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• pp.135-138
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• 2009

포토닉 의류는 의류에 다양한 광원과 광전달 소재를 적용하여 빛을 발현하는 디지털 기술을 적용하여 의류의 색채를 제어함으로써 착용자의 감성을 시각화할 수 있도록 하는 스마트 의류의 일종이다. 앞서 개발한 포토닉 의류의 중 LED램프와 광섬유의 조합으로 색광을 발현하는 기능은 특별히 RGB 색조합을 통해 의도하는 색채를 다양하게 구현할 수 있다는 특징이 있다. 현재 색채 발현 방법은 Red, Green, Blue의 3가지 색상의 LED의 적절한 조합을 통하여 색채를 발현하는 방식을 가지고 있으나 색체계 상의 기준 색상과 실제 발현되어 육안으로 확인되는 색채의 차이가 있어 의도와는 다른 색채가 나타나 디자이너의 색채 기획의도를 포토닉 의류에 적용하기 힘들며, 기존의 색체계에 의해 생산된 다른 텍스타일 색채와의 컬러 조합에 있어서 필요한 정확한 데이터를 얻기 어렵다. 따라서, 포토닉 의류에 의도하는 색채를 발현하기 위해서는 기존 색상과의 차이점 보정과 효과적인 데이터 베이스 구축이 필요하다. 본 연구에서는 포토닉 의류의 색채에 관한 보다 체계적인 연구를 통해 웹 컬러와 광섬유를 이용한 포토닉 컬러에서의 색채 이미지를 비교, 분석하고 RGB값과 색차값을 통한 차이점 보정을 참고하여 광섬유를 사용하여 제작되는 스마트 포토닉 의류의 제작 시 색채선정 기획에 있어서 기초적인 자료로 활용될 수 있도록 제시하고자 한다.