• 한국지구과학회지
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• 제34권3호
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• pp.257-273
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• 2013

본 연구는 과학관 도슨트의 활동에 대한 전문화 방안을 모색하는데 목적을 두고 8년간 도슨트 활동을 지속한 박 도슨트를 연구 참여자로 선정하여 생애사적 접근방법으로 연구하였다. 박 도슨트 선정과정은 다음과 같다. 1단계 목적표집, 편의표집을 통해 56명의 도슨트를 선정, 2단계 심화연구 수락자를 기준으로 목적표집을 통해 11명의 도스트를 선정했다. 11명을 대상으로 설문지 분석과 심층면담을 거쳐 본 연구에 적극적인 1인을 3단계 목적표집을 통해 선정하였다. 주로 면담을 실시하고 참여관찰과 문서 등의 수집 분석을 통해 박 도슨트가 어떻게 도슨트 활동을 하게 되었는지, 그리고 현재의 도슨트 활동은 어떠한지, 도슨트 전문성을 위해 어떠한 노력을 하는지 등을 생애사적으로 기술하였다. 연구의 결과는 다음과 같다. 첫째, 박 도슨트는 교육적 신념이 투철하며 이는 생애사적 경험을 통해 형성된 신념이 무엇보다도 도슨트 활동에 큰 영향을 미치고 있음을 알 수 있다. 둘째, 박 도슨트는 활동을 통해서 전시해설에 관한 실천적 지식이 형성 및 체계화 되고 있었다. 셋째, 박 도슨트는 전문가로 활동하기 위해서 전시해설을 위한 전문성을 기르고 이를 좀 더 효과적으로 획득할 수 있는 방법으로 주변 환경을 충분히 활용하고 있었다. 연구 결과를 바탕으로 체계적인 도슨트 제도의 구축 및 운영과 도슨트 활동에 따른 지원 및 구축은 과학관에서의 도슨트 교육의 활성화를 위해서는 중요한 부분임을 인식할 수 있다.

• Progress in Superconductivity
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• 제2권1호
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• pp.6-10
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• 2000

New cuprates with the nominal composition $(Pb_{0.75}Sn_{0.25})Sr_2(Ca_{1-x}Lu_x)Cu_2O_z(x=0.4{\sim}1.0)$ have been synthesized. These materials exhibit superconducting properties for 0.4 $\leq$ x $\leq$ 0.7. It is also observed that the superconductivity of the as-prepared sample is enhanced by post-annealing at high temperature followed by quenching. X-ray diffraction analysis reveals that the c lattice parameter decreases as x increases whereas the a lattice parameter is nearly independent of the value of x for both the as-prepared and the post-treated samples. The thermoelectric power measurements indicate that the post-heat-treatments result in an increase in the hole carrier density which account for the observed increase of $T_c$. Bulk superconductivity with a $T_c$ value of 60 K is observed in this system.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제16권4호
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• pp.427-441
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• 2009

The method of Lattice Dynamical System is used to establish a global model on an infinite chain of many local markets interacting each other through a diffusion of prices between them. This global model extends the Walrasian evolutionary cobweb model in an independent single local market to the global market evolution. We assume that each local market has linear decreasing demands and quadratic supplies with naive predictors, and investigate the stationary behaviors of global price dynamics and show that their dynamics are conjugate to those of $H{\acute{e}}non$ maps and hence can exhibit complicated behaviors such as period-doubling bifurcations, chaos, and homoclic orbits etc.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제17권1호
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• pp.93-106
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• 2010

We employ the methods of Lattice Dynamical System to establish a global model extending the Walrasian evolutionary cobweb model in an independent single local market to the global market evolution over an infinite chain of many local markets with interaction of each other through a diffusion of prices between them. For brevity of the model, we assume linear decreasing demands and logistic supplies with naive predictors, and investigate the traveling wave behaviors of global price dynamics and show that their dynamics are conjugate to those of H$\acute{e}$non maps and hence can exhibit complicated behaviors such as period-doubling bifurcations, chaos, and homoclic orbits etc.

• 한국지구과학회지
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• 제26권5호
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• pp.376-386
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• 2005

이 연구는 비형식적 교육기관인 자연사 박물관의 전시를 학교 과학교육에 활용하기 위한 장기적인 목적 하에, 과학교육과정의 주요한 목표 중의 하나인 과학의 본성 측면이 박물관의 전시에 어떻게 반영되고 있는지를 살펴본 기술적 연구이다. 국내 4개 자연사박물관 혹은 자연사 전시실의 전시 중에서 과학 탐구 중심의 전시와 과학사 사례 중심의 전시를 대상으로, 전시매체, 그리고 설명문의 서술방식과 내용에서 반영되는 과학의 본성은 어떤지를 살펴보았다. 설명문의 서술방식은 확정적인지 해석적인지를 살펴보았고, 내용으로는 과학자 중심, 과학자 집단 논의, 사회 문화적 배경, 주장에 대한 근거, 과학지식의 변화가능성 여부를 살펴보았다. 이 연구 결과를 통해 전체적으로 자연사박물관에 과학의 본성 측면이 드러난 전시가 풍부하지 않음을 파악할 수 있었으며, 따라서 의도적으로 과학의 본성 교육을 위한 전시가 절실히 필요하다는 점을 알 수 있다. 이 연구의 결과는 학교과학교육에서 접근하기 어려운 과학의 본성을 교육시키기 위한 훌륭한 자료 원으로서 자연사박물관의 전시 및 교육의 방향과 개선 방안을 위한 기초 자료를 제공한다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권3호
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• pp.256-265
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• 2017

In this paper, an ascheme is proposed for multiuser underwater acoustic communication by using the multi-chirp rate signals. It differs from the well known TDMA (Time Division Multiple Access), FDMA (Frequency Division Multiple Access) or CDMA (Code Division Multiple Access), by assigning each users with different chirp-rate carriers instead of the time, frequency or PN code. Multi-chirp rate signals can be separated from each other by FrFT (Fractional Fourier Transform), which can be regarded as the chirp-based decomposing, and superior to the match filter in the underwater acoustic channel. VTRM (Virtual Time Reverse Mirror) is applied into the system to alleviate the ISI caused by the multipatch and make the equalization more simple. Results of computer simulations and pool experiments prove that the proposed multiuser underwater acoustic communication based on the multi-chirp rate exhibit well performance. Outfield experments carrie out in Xiamen Port show that using about 10 kHz bandwidth, four users could communicate at the same time with 425 bps with low BER and can match the UAC application.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권4호
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• pp.1548-1568
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• 2015

Korea's Compulsive Shutdown System bans online game providers from offering their services to children under 16 years of age from midnight to 6 a.m. Although it was introduced only after lengthy rounds of discussion, controversy over the system still continues. The key question is whether the system, which unilaterally emphasizes juvenile protection, infringes upon the freedom of playing games for teenagers, the freedom of business for game products related business operators and the right to foster children for parents, which are basic rights under the Constitution. It is very encouraging that the State took up the issue and prepared various systems for juvenile protection through the Compulsive Shutdown System. Yet the government has to plan as comprehensive and effective of a measure as it possibly can by predicting the trends of technology development and game use, and also set detailed standards to ensure that the system should not become an excessive or inappropriate regulation. Although the State's compulsive intervention may be positive since it is hard to expect a self purification capability to exhibit itself concerning game use among teenagers, a plan to prevent game addiction among adolescents from the long-term and fundamental perspectives should be prepared as well.

• 아동학회지
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• 제31권2호
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• pp.263-275
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• 2010

While child care policy has mainly focused on the financial support for child care centers, the Ministry of Health, Welfare and Family Affairs recently announced the introduction of a child care allowances. The purpose of this study is to investigate how mothers and directors of child care centers perceived this child care allowance. One hundred and seventeen directors and one hundred and fifty six mothers in the Seoul, Kyunggi-Do, and Cheonbuk-Do areas participated in the survey. The results demonstrated that both the mothers and the directors of child care center exhibit more differences than similarities in terms of their views of child care allowances. Moreover, the perception on some issues of child care allowance differed significantly depending on the types of child care center in question, the mother's economic participation or family income. Issues of importance to the successful introduction of a child care allowance system were also discussed.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2003년도 춘계학술발표대회 논문집
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• pp.123-126
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• 2003

Internationally, Korean people and society are known to be workaholic, however, recently some changes have come with the inauguration of the 5 working-days system as well as the rising of economic power and high level of education. Many people come to enjoy leisure time with various activities. Especially, arts become the subject of concern as a kind of leisure life, and also gallery become a important space. However, the renovation of the gallery space is required Inevitably because many galleries have been located in too formal or fixed building space, and the management of it has not been executed thoroughly. This study aims at the suggestion of the specialized and differentiated renovation plan for gallery as cultural space offering the right notion and information about the arts as well as rest to citizens, also as exhibit space showing the object efficiently.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.424-426
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• 1999

In this paper, the design characteristics, the manufacturing process and the results of performance test on the AC traction motor for urban transit standard E.M.U which is newly developed with applying standardization specification will be introduced. It is reviewed that the design and performance analysis on conventional motors considering system correlation and design constraint and the design optimization through an analysis of electro-magnetic, thermal and dynamic properties. The properties of factory products manufactured by 200 Class VPI process exhibit a excellent performance with a lower noise and vibration, higher efficiency and power factor etc.