• Structural Engineering and Mechanics
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• v.25 no.4
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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.

• Journal of the Korean Society of Combustion
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• v.9 no.3
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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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• v.10 no.4
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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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• v.9 no.6
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• pp.288-298
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• 2004

• Korean Journal of Comparative Education
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• v.27 no.1
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• pp.123-144
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• 2017

The purpose of the study was to analyze American teacher quality management system and provide it's implications. For this, the study analyzed the main traits of American teacher policy, Pennsylvania State University's teacher cultivation system, Pennsylvania State's teacher certification, selection, and recruit system, the master teacher system of New Jersey and New York State. The main results are as the followings. First, American teacher policy is variously operated by state government and school district based on variety and autonomy. Second, for teacher cultivation in American teacher policy, the evaluation on the teacher cultivation program of teacher cultivation institute(mainly university) is strictly administrated. Third, for teacher certification, various tests for gaining teacher certificate are administered and standardized tests are used for the tests. Fourth, for teacher selection and recruit, there is no special test for selection and teacher recruit is done by contract. Fifth, for quality management using excellent teacher, America is administering master teacher that is similar with master teacher system in Korea. Finally, the innovation of teacher cultivation institute by introducing Every Student Succeeds Act(ESSA) is anticipated. Based on these results, the implications for Korean teacher policy were provided.

• 월간낙농육우
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• v.29 no.6
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• pp.124-127
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• 2009

• Proceedings of the KSMRM Conference
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• 1996.10a
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• pp.93-112
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• 1996

• Proceedings of the Korean Nutrition Society Conference
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• 1996.11b
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• pp.46-46
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• 1996

• Journal for History of Mathematics
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• v.12 no.2
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• pp.159-165
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• 1999

• Proceedings of the Korean Vacuum Society Conference
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• 1996.02a
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• pp.119-119
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• 1996