• Structural Engineering and Mechanics
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• 제25권4호
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• pp.365-382
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• 2007

A pilot study has been conducted to guide the development of a finite element modeling formulation for the analysis of architectural glass curtain walls under in-plane lateral load simulating earthquake effects. This pilot study is one aspect of ongoing efforts to develop a general prediction model for glass cracking and glass fallout for architectural glass storefront and curtain wall systems during seismic loading. For this study, the ANSYS finite element analysis program was used to develop a model and obtain the stress distribution within an architectural glass panel after presumed seismic movements cause glass-to-frame contact. The analysis was limited to static loading of a dry-glazed glass curtain wall panel. A mock-up of the glass curtain wall considered in the analysis with strain gages mounted at select locations on the glass and the aluminum framing was subjected to static loading. A comparison is made between the finite element analysis predicted strain and the experimentally measured strain at each strain gage location.

• 한국연소학회지
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• 제9권3호
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• pp.10-18
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• 2004

An experimental study of the effect of operating conditions on the behavior of a lean premixed laboratory combustor operating on natural gas has been conducted. Measurements were made characterizing the pressure fluctuations in the combustor and the flame structure over a range of inlet temperatures, inlet velocities and equivalence ratios. In addition the fuel distribution at the inlet to the combustor was varied such that it was an independent parameter in the experiment. Inlet temperature, inlet velocity and equivalence ratio were all found to have an effect on the stability characteristics of the combustor. The nature of this effect, however, depended on the fuel distribution. For example, with one fuel distribution the combustor would become unstable when the temperature was increased, whereas with a different fuel distribution the combustor would become unstable when the temperature was decreased. Similarly, the operating conditions had an effect on the flame structure. For example the intensity-weighted center of mass of the flame was found to move closer to the center body as either the temperature or equivalence ratio increased. It was interesting and somewhat surprising to note, however, that as the location of the center of mass changed with operating conditions it did so by moving along a line of constant flame angle.

• Structural Engineering and Mechanics
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• 제10권4호
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• pp.405-426
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• 2000

Two approximate methods based on mechanism analysis suitable for seismic assessment/design of structural concrete are reviewed. The methods involve use of equal energy concept or equal displacement concept along with appropriate patterns of inelastic deformations to relate structure's maximum lateral displacement to member and plastic deformations. One of these methods (Clough's method), defined here as a ductility-based approach, is examined in detail and a modification for its improvement is suggested. The modification is based on estimation of maximum inelastic displacement using inelastic design response spectra (IDRS) as an alternative to using equal energy concept. The IDRS for demand displacement ductilities are developed for a single degree of freedom model subjected to several accelerograms as functions of response modification factor (R), damping ratios, and strain hardening. The suggested revised methodology involves estimation of R as the ratio of elastic strength demand to code level demand, and determination of design base shear using $R_{design}{\leq}R$ and maximum displacement, determination of plastic displacement using IDRS and subsequent local plastic deformations. The methodology is demonstrated for the case of a 10-story precast wall panel building.

• Environmental Engineering Research
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• 제9권6호
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• pp.288-298
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• 2004

• 비교교육연구
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• 제27권1호
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• pp.123-144
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• 2017

본 연구의 목적은 미국의 교원 질 관리체제에 관한 사례를 분석하고 그 시사점을 제공하는 것이다. 이를 위해 미국 교원정책의 주요 특징, 펜실베이니아주립대학교의 교원양성체제, 펜실베이니아주의 교원자격, 선발 및 임용체제, 뉴저지주 및 뉴욕주의 수석교사제를 분석하였다. 주요결과는 다음과 같다. 첫째, 미국의 교원정책은 다양성과 자율성을 기반으로 주정부 및 학교구에 따라 다양하게 운영되고 있어 일률적으로 제시하기가 어렵다. 둘째, 미국의 교원정책에서 교원양성의 경우 교원양성기관(주로 대학)의 교원양성 프로그램에 대한 평가를 엄격히 시행하고 있다. 셋째, 교원자격의 경우 교원자격증 취득을 위한 다양한 시험제도를 운영하고 있으며, 시험은 별도로 시행하는 것이 아니라 모두 표준화된 시험을 사용하고 있다. 넷째, 교원 선발 및 임용(채용)의 경우 선발을 위한 별도의 시험제도는 없으며, 임용(채용)은 계약직으로 이루어진다. 다섯째, 우수교원을 활용한 질 관리의 경우 미국은 수석교사제를 운영하고 있으며, 이는 우리나라에서 현재 운영 중인 수석교사제와 비슷하다고 할 수 있다. 마지막으로, 최근 "모든 학생의 성공법"의 도입으로 교원양성기관의 개혁이 예상된다. 이러한 주요결과를 토대로 한국 교원정책을 위한 시사점을 제시하였다.

• 월간낙농육우
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• 제29권6호
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• pp.124-127
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• 2009

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 1996년도 추계학술대회 초록집
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• pp.93-112
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• 1996

• 한국영양학회:학술대회논문집
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• 한국영양학회 1996년도 추계학술대회 초록
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• pp.46-46
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• 1996

• 한국수학사학회지
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• 제12권2호
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• pp.159-165
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• 1999

• 한국진공학회:학술대회논문집
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• 한국진공학회 1996년도 제10회 학술발표회 논문개요집
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• pp.119-119
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• 1996