• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.433-438
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• 1998

Design lateral strength calculated by current seismic design code is prescribed to be much lower than the force level required for a structure to respond elastically during design level earthquake ground motion. Present procedures for calculating seismic design forces are based on the use of elastic spectra reduced by a strength reduction factor known as "response modification factor, R". This factor accounts for the inherent ductility, overstrength, redundancy, and damping of a structural system. This study considers ductility and overstrength of the wall-type structure for investigating R factor. This means that R factor is determined from the product of "ductility-based R factor($R_$\mu$$) and overstrength factor($R_s$). $R_$\mu$$ factor is calibrated to attain the targer ductility ratio (system ductility capacity) and produced in the from of $R_$\mu$$ spectra considering the influence of target ductility, natural period, and hysteretic model. On the other hand, $R_s$ is more difficult to quantify, since it depends on both material and system-dependent uncertain parameters. In this study Rs factor was determined from the result of push-over analysis.-over analysis.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.75-85
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• 2010

A new freeform structure representing "Diagrid, Cantilevered, Tilted." which has been considered not only its distinctive appearance but also the structural advantages becomes one of the trends in tall building design. Especially in the Diagrid system, loads can be distributed through bracing frame so that it can be save the materials since it has more effective in the structure behavior. But the seismic performance index such as response modification factor is not clearly defined yet. Even though the diagrid is supposed to show higher seismic performance, it is underestimated due to the lack of reliable data. In this paper the response modification factor for the diagrid system is experimentally explored.

• Journal of The Korean Association For Science Education
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• v.24 no.3
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• pp.596-611
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• 2004

Based on conceptual change theory, cognitive conflict is known as an important factor for conceptual change even though there are still questions about its positive and negative effects on science learning. However there are little research which propose types of meaningful(constructive) cognitive conflict in learning science. The purpose of this study is to find out how are the anxiety types of cognitive conflict to which high school students respond in the action-reaction task, and to reveal what's the characteristic of the explanatory hypothesis according to the anxiety types. The result of this study indicated that first, the characteristics of the anxiety types of the cognitive conflict were classified as eight types. Especially the students who belong to the types of conviction of logical misconception and reasonable modification suggested explanatory hypothesis close to physical nature. On the other hand, the students who showed other types of anxiety except the two types of anxiety suggested temporary supported hypothesis or simple explanatory hypothesis based on students' observation and intuition. Finally we discussed the importance and the implication of the types of anxiety in applying the cognitive conflict strategy to science instruction.