• 대한화학회지
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• 제60권1호
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• pp.59-68
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• 2016

최근 과학교육에서 강조되고 있는 과학적 소양의 함양은 과학 지식이 형성되는 일련의 탐구 과정을 경험하고 이해함으로써 향상될 수 있다. 이러한 관점에서 미국연구회(NRC)의 차세대과학기준(NGSS)은 학생들의 과학 탐구 과정 경험과 이해를 돕기 위하여 8가지 과학 실천(8 Practices of Science)을 제안하였고, 8가지 과학 실천 각각에 대하여 학년 군별 세부성취 목표를 제시하고 있다. 본 연구에서는 2009 개정 교육과정에 따른 고등학교 화학II교과서 4종에 포함된 탐구 활동을 8가지 과학 실천과 9-12학년군 세부 성취 목표를 기준으로 분석하였다. 4종의 화학II교과서에 포함된 탐구 활동은 총 173개 이고 분석된 과학 실천은 총 678개 이었다. 4종 화학II교과서의 탐구 활동에 포함된 과학 실천은 ‘자료 분석하고 해석하기’가 가장 많았고, ‘증거에 입각하여 논의하기’, ‘정보를 얻고 평가하고 의사소통하기’등은 상대적으로 그 기회가 부족하였으며, ‘질문하고 문제 규정하기’와 ‘모형 개발하고 사용하기’는 거의 포함되어 있지 않았다.

• 방송공학회논문지
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• 제14권4호
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• pp.475-487
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• 2009

We propose a visible light road-to-vehicle communication system at intersection as one of ITS technique. In this system, the communication between vehicle and a LED traffic light is approached using LED traffic light as a transmitter, and on-vehicle high-speed camera as a receiver. The LEDs in the transmitter are emitted in 500Hz and those emitting LEDs are captured by a high-speed camera for making communication. Here, the luminance value of each LED in the transmitter should be found for consecutive frames to achieve effective communication. For this purpose, first the transmitter should be identified, then it should be tracked for consecutive frames while the vehicle is moving, by processing the images from the high-speed camera. In our previous work, the transmitter was identified by getting the subtraction of two consecutive frames. In this paper, we mainly introduce an algorithm to track the identified transmitter in consecutive frames. Experimental results using appropriate images showed the effectiveness of the proposal.

• 한국학교보건학회지
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• 제32권2호
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• pp.77-87
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• 2019

Purpose: This study was conducted to examine the prevalence of current smoking and the factors that influence current smoking among male high school students in Korea according to school type. Methods: Data were extracted from the Korea Youth Risk Behavior Web-Based Survey (2017) and multiple logistic regression was used based on complex sample analysis. The study sample comprised of 15,777 male high school students: 12,583 from general high schools (GHS) and 3,194 from specialized vocational high schools (SVHS). Results: The prevalence of current smoking was significantly higher in SVHS students (19.6%) compared to GHS students (12.6%). Low academic achievement, depressive symptoms, current drinking, and high household economic status were commonly associated with current smoking in male students from both school types. However, exposure to secondhand smoking at home, non-exposure to anti-smoking advertisement, exposure to tobacco advertisement, participation in smoking prevention or cessation education were related to current smoking in GHS students, while living in rural area was associated with current smoking in SVHS students. Conclusion: To reduce current smoking among male high school students, it is necessary to develop smoking prevention policies reflecting the factors associated with current smoking that are different by school type.

• 한국과학교육학회지
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• 제36권1호
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• pp.159-166
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• 2016

과학수업에서의 거꾸로 수업에 대한 이해와 경험을 바탕으로 거꾸로 수업을 적용하는데 겪는 어려움을 면담조사방법을 활용하여 분석하였다. 면담자는 서울, 경기에 근무하고 있는 교사 중 거꾸로 수업 경력을 기준으로 과학 교과에 2년 이상 거꾸로 수업을 운영한 경험을 가진 교사와 올해 처음 거꾸로 수업을 운영하기 시작한 교사를 초 중 고 학교급별로 각 1명 씩 총 6명을 선정하였다. 참여한 교사들에게 3단계 면담 조사를 실시한 결과, 초중고 과학 수업에서 거꾸로 수업 수행에 매우 높은 만족감을 나타내었다. 특히 탐구활동에 거꾸로 수업이 많은 도움이 된다고 하였다. 그러나 교사들은 수업 준비에 부담감을 가지고 있었으며 수업 구성에 대한 어려움을 겪고 있었다. 거꾸로 수업의 어려움 해결 방안에 대한 탐색으로서 교과서 체제에 대한 논의를 통해 현재의 수업을 개선하는데 다양한 시사점을 도출할 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.19-19
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• 2009

TiNxOy/TiNx multilayer thin films with a high resistance (~ k$Omega$) were deposited on SiO2/Si substrates at room temperature by sputtering. The TiNx thin films show island and smooth surface morphology in samples prepared by dc and rf magnetron sputtering, respectively. TiNxOy/TiNx multilayer has been developed to control temperature coefficient of resistance (TCR) by the incorporation of TiNx layer (positive TCR) inserted into TiNxOy layers(negative TCR). Electrical and structural properties of sputtered TiNxOy/TiNx multilayer films were investigated as a function of annealing temperature. In order to achieve a stable high resistivity, multilayer films were annealed at various temperatures in oxygen ambient. Samples annealed at 700 oC for 1 min exhibit a good TCR value and a stable high resistivity.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.231-234
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• 2003

This paper presents a novel high frequency transformer linked full-bridge type soft-switching phase-shift PWM control scheme DC-DC power converter, which can be used as power conditioner fur small-scale fuel cell power generation system. Using full-bridge soft-switching DC-DC converter topology makes possible to use low voltage high performance MOSFETs to achieve high efficiency of the power conditioner. A tapped inductor filter is implemented in the proposed soft-switching converter topology to achieve soft-switching PWM constant high frequency operation for a wide load variation range. to minimize circulating and idling currents without using additional resonant circuit and auxiliary power switching devices. The practical effectiveness of the proposed soft-switching DC-DC converter is verified in laboratory level experiment with 1 kW 100kHz breadboard setup using power MOSFETs. Actual efficiency of 94-96$\%$ is obtained for the wide load range

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제24권3호
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• pp.179-190
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• 2017

In this paper, we introduce and solve the following quadratic (${\rho}_1$, ${\rho}_2$)-functional inequality (0.1) $$N\left(2f({\frac{x+y}{2}})+2f({\frac{x-y}{2}})-f(x)-f(y),t\right){\leq}min\left(N({\rho}_1(f(x+y)+f(x-y)-2f(x)-2f(y)),t),\;N({\rho}_2(4f(\frac{x+y}{2})+f(x-y)-2f(x)-2f(y)),t)\right)$$ in fuzzy normed spaces, where ${\rho}_1$ and ${\rho}_2$ are fixed nonzero real numbers with ${{\frac{1}{{4\left|{\rho}_1\right|}}+{{\frac{1}{{4\left|{\rho}_2\right|}}$ < 1, and f(0) = 0. Using the fixed point method, we prove the Hyers-Ulam stability of the quadratic (${\rho}_1$, ${\rho}_2$)-functional inequality (0.1) in fuzzy Banach spaces.

• Korean Journal of Mathematics
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• 제16권3호
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• pp.413-424
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• 2008

In [21], Th.M. Rassias proved that the norm defined over a real vector space V is induced by an inner product if and only if for a fixed integer $n{\geq}2$ $$n{\parallel}\frac{1}{n}\sum\limits_{i=1}^{n}x_i{\parallel}^2+\sum\limits_{i=1}^{n}{\parallel}x_i-\frac{1}{n}\sum\limits_{j=1}^{n}x_j{\parallel}^2=\sum\limits_{i=1}^{n}{\parallel}x_i{\parallel}^2$$ holds for all $x_1,{\dots},x_n{\in}V$. We consider the functional equation $$nf(\frac{1}{n}\sum\limits^n_{i=1}x_i)+\sum\limits_{i=1}^{n}f(x_i-\frac{1}{n}\sum\limits_{j=1}^{n}x_j)=\sum\limits_{i=1}^nf(x_i)$$ Using fixed point methods, we prove the generalized Hyers-Ulam stability of the functional equation $$(1)\;2f(\frac{x+y}{2})+f(\frac{x-y}{2})+f(\frac{y-x}{2})=f(x)+f(y)$$.

• 한국환경교육학회지:환경교육
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• 제14권2호
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• pp.116-132
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• 2001

The goal of the environmental education in High School is to make students survey and work out the issues on environment and to help them continue and improve the work. It is important that we should educate students the rational ability of decision-making. The more they can make decisions rationally, the more they participate actively in that. The purpose of this study is to develope the model of a new teaching-learning method coinciding with the goal of the environmental education of Social studies in High School. This study is backed up by the following developing processes. To begin with, the contents related to environmental problems in Social Studies Curriculum are being investigated. To urge the importance of STS(Science, Technology and Society), 1 will present the righteous understanding of Science in societal contexts, the development of rational decision-making abilities, and the cognitive connections between society and science. For this, 1'm representing a new model of learning-teaching method, backed up by Constructivism, especially Vygotsky's ZPD theory, giving 4 steps from everyday concepts to natural lingistic thought. Based on the above hypothesis, at last I will represent a STS whose topic is a problem of beach preservation because I intend to show the possibility of STS on the environmental education of Social Studies through this study. This study will help us lay a foundation stone of introducing STS in environmental education of Social Studies.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.228-231
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• 2002

We report the effect of density of thin films on moisture adsorption and hydration of MgO thin film, usually used as a protective layer in AC-PDP After hydration, lots of hemispherical shaped clusters, $Mg(OH)_2$, formed on the surface of MgO thin films. However clusters formed on low-density thin films were bigger than those on high-density films. From ERD spectra, it seemed that the concentration of hydrogen was very high in the region 20 nm from the surface of MgO thin film. The low-density thin film had more hydrogen than high-density thin film. From simulation results of ERD and RBS it was found that hydration reaction also occurred in the inner part of the film. So diffusion of Mg atoms from the inner part of the film to the surface and $H_2O$ molecules from the surface to the inner part of the film is important. And because low density thin film has many short paths for diffusion of Mg atoms and $H_2O$ molecules, low-density thin film is more hydrated. So to suppress hydration of MgO thin films, high-density thin film is needed.