• Architectural research
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• v.20 no.2
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• pp.53-64
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• 2018

A nonlinear analytical model has been proposed for two-span two-story reinforced concrete frames with relaxed section details. The analytical model is composed of beam, column, and beam-column joint elements. The goal of this study is to develop a simple and light nonlinear model for two-dimensional reinforced concrete frames since research in earthquake engineering is usually involved in a large number of nonlinear dynamic analyses. Therefore, all the nonlinear behaviors are modeled to be concentrated on flexural plastic hinges at the end of beams and columns, and the center of beam-column joints. The envelope curve and hysteretic rule of the nonlinear model for each element are determined based on experimental results, not theoretical approach. The simple and light proposed model can simulate the experimental results well enough for nonlinear analyses in earthquake engineering. Consequently, the proposed model will make it easy to developing a nonlinear model of the entire frame and help to save time to operate nonlinear analyses.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.541-546
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• 1998

The objective of this research is to observe the actual response of low-rise nonseismic moment-resisting infilled reinforced concrete frame subjected to varied levels of earthquake ground motions. First of all, the reduction scale for the model was determined as 1 : 5 considering the capacity of the shaking table to be used. This model was, then, subjected to the shaking table motions simulating Taft N21E component earthquake ground motions, whose peak ground accelerations(PGA`s) were modified to 0.12g, 0.2g, 0.3g, and 0.4g. The global behavior and failure mode were observed. The lateral accelerations and displacements at each story and local deformations at the critical portions of structure were measured. Before and after each earthquake simulation test, free vibration tests were performed to find the changes in the natural period of the model.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.427-432
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• 1998

The objective of this research is to observe the actual response of low-rise nonseismic moment-resisting reinforced frame subjected to varied levels of earthquake ground motions. First of all, the reduction scale for the model was determined as 1 : 5 considering the capacity of the shaking table to be used. This model was, then, subjected to the shaking table motions simulating Taft N21E component earthquake ground motions, whose peak ground accelerations(PGA's) were modified to 0.12g, 0.2g, 0.3g, and 0.4g. The global behavior and failure mode were observed. The lateral accelerations and displacements at each story and local deformations at the critical portions of structure were measured. The base shear was measured by using specially made load cells. Before and after each earthquake simulation test, free vibration tests were performed to find the changes in the natural period and damping ratio of the model.

• International Journal of Concrete Structures and Materials
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• v.7 no.3
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• pp.175-182
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• 2013

A damage-based approach for the performance-based seismic assessment of reinforced concrete frame structures is proposed. A new methodology for structural damage assessment is developed that utilizes response information at the material level in each section fiber. The concept of the damage evolution is analyzed at the section level and the computed damage is calibrated with observed experimental data. The material level damage parameter is combined at the element, story and structural level through the use of weighting factors. The damage model is used to compare the performance of two typical 12-story frames that have been designed for different seismic requirements. A series of nonlinear time history analyses is carried out to extract demand measures which are then expressed as damage indices using the proposed model. A probabilistic approach is finally used to quantify the expected seismic performance of the building.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.72-77
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• 2003

In this paper, an experimental verification of system identification technique for constructing finite element model is conducted for a three-story test structure equipped with an active mass driver (AMD). Twenty Gaussian white noises were used as the input for AMD, and the corresponding accelerations of each floors are measured. Then, the complex frequency response function (FRF) for the input, the force induced by the AMD, was obtained and subsequently, the Markov parameters and system matrices were estimated. The magnitudes as well as phase of experimentally obtained FRFs match well with those of analytically obtained FRFs.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.6
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• pp.13-20
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• 2012

In this study, 5-story structures were designed in accordance with KBC2009 for inelastic time history analysis of RC IMRF. Bending moment-curvature relationship for beam and column was identified with fiber model and bending moment-rotation relationship for beam-column joint was calculated with simple and unified joint shear behavior model and moment equilibrium relationship for the joint. The hysteretic behavior was simulated with three-parameter model suggested in IDARC program. The analytical results showed that the inelastic shear behavior of the joint could be neglected in the structural design for seismic design category C but the structure of category D did not satisfy the criteria of FEMA 356 for collapse prevention performance level.

• Journal of Korean Association for Spatial Structures
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• v.21 no.2
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• pp.57-66
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• 2021

This study develops finite element models for seismically-deficient reinforced concrete building frame retrofitted using fiber-reinforced polymer jacketing system and validates the finite element models with full-scale dynamic test for as-built and retrofitted conditions. The bond-slip effects measured from a past experimental study were modeled using one-dimensional slide line model, and the bond-slip models were implemented to the finite element models. The finite element model can predict story displacement and inter-story drift ratio with slight simulation variation compared to the measured responses from the full-scale dynamic tests.

• MISULJARYO - National Museum of Korea Art Journal
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• v.100
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• pp.50-80
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• 2021

This paper critically examines the history of the theories connected to the Wongaksa Temple Pagoda that have developed over the last 100 years focusing on the original number of stories the pagoda would have reached. Part II of this paper retraces the dynamic process of the rediscovery of the Wongaksa Temple Pagoda by Westerners who traveled to Korea during the port-opening period. Koreans at the time viewed the Wongaksa Temple Pagoda as an object of no particular appeal or even as an eyesore. However, Westerners appreciated it as a wonder or magnificent sight. Since these Westerners had almost no prior knowledge of Buddhist pagodas, they were able to write objective travelogues. At the time, these visitors generally accepted the theory common among Joseon intellectuals that Wongaksa Temple Pagoda once had thirteen stories. Part III focuses on Japanese government-affiliated scholars' academic research on the Wongaksa Temple Pagoda after the proclamation of the Korean Empire and the Japanese Government-General of Korea's subsequent management of the pagoda as a cultural property during the colonial era. It also discusses issues with Japanese academic research and management. In particular, this portion sheds light on the shift in theories about the original number of stories of the Wongaksa Temple Pagoda from the ten-story theory supported by Sekino Tadashi (關野 貞), whose ideas have held a great influence on this issue over the last 100 years, to the thirteen-story theory and then to the idea that it had more than thirteen. Finally, Part IV addresses the change from the multi-story theory to the ten-story theory in the years after Korea's liberation from Japan until 1962. Moreover, it highlights how Korean intellectuals of the Japanese colonial era predominantly accepted the thirteen-story theory. Since 1962, a considerable quantity of significant research on the Wongaksa Temple Pagoda has been published. However, since most of these studies have applied the ten-story theory suggested in 1962, they are not individually discussed in this paper. This retracing of the history of theories about the Wongaksa Temple Pagoda has verified that although there are reasonable grounds for supporting the thirteen-story theory, it has not been proved in the last 100 years. Moreover, the number of pagoda stories has not been fully discussed in academia. The common theory that both Wongaksa Temple Pagoda and Gyeongcheonsa Temple Pagoda were ten-story pagodas was first formulated by Sekino Tadashi 100 years ago. Since the abrasion of the Wongaksa Temple Stele was so severe the inscriptions on the stele were almost illegible, Sekino argued that the Wongaksa Temple Pagoda was a ten-story pagoda based on an architectural analysis of the then-current condition of the pagoda. Immediately after Sekino presented his argument, a woodblock-printed version of the inscriptions on the Wongaksa Temple Stele was found. This version included a phrase that a thirteen-story pagoda had been erected. In a similar vein, the Dongguk yeoji seungnam (Geographic Encyclopedia of Korea) published by the orders of King Seongjong in the late fifteenth century documented that Gyeongcheonsa Temple Pagoda, the model for the Wongaksa Temple Pagoda, was also a thirteen-story pagoda. The Wongaksa Temple Stele erected on the orders of King Sejo after the establishment of the Wongaksa Temple Pagoda evidently shows that Sekino's ten-story premise is flawed. Sekino himself wrote that "as [the pagoda] consists of a three-story stereobate and a ten-story body, people call it a thirteen-story pagoda," although he viewed the number of stories of the pagoda body as that of the entire pagoda. The inscriptions on the Wongaksa Temple Stele also clearly indicate that the king ordered the construction of the Wongaksa Temple Pagoda as a thirteen-story pagoda. Although unprecedented, this thirteen-story pagoda comprised a ten-story pagoda body over a three-story stereobate. Why would King Sejo have built a thirteen-story pagoda in an unusual form consisting of a ten-story body on top of a three-story stereobate? In order to fully understand King Sejo's intention in building a thirteen-story pagoda, analyzing the Wongaksa Temple Pagoda is necessary. This begins with the restoration of its original name. I disprove Sekino's ten-story theory built upon flawed premises and an eclectic over-thirteen-story theory and urge applying the thirteen-story theory, as the inscriptions on the Wongaksa Temple Stele stated that the pagoda was originally built as a thirteen-story pagoda.

• Steel and Composite Structures
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• v.21 no.1
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• pp.93-107
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• 2016

Seismic fragility analysis is a probabilistic decision-making framework which is widely implemented for evaluating vulnerability of a building under earthquake loading. It requires ingredient named probabilistic model and commonly developed using statistics requiring collecting data in large quantities. Preparation of such a data-base is often costly and time-consuming. Therefore, in this paper, by developing generic seismic drift demand model for regular-multi-story steel moment resisting frames is tried to present a novel application of the probabilistic decision-making analysis to practical purposes. To this end, a demand model which is a linear function of intensity measure in logarithmic space is developed to predict overall maximum inter-story drift. Next, the model is coupled with a set of regression-based equations which are capable of directly estimating unknown statistical characteristics of the model parameters.To explicitly address uncertainties arise from randomness and lack of knowledge, the Bayesian regression inference is employed, when these relations are developed. The developed demand model is then employed in a Seismic Fragility Analysis (SFA) for two designed building. The accuracy of the results is also assessed by comparison with the results directly obtained from Incremental Dynamic analysis.

• Journal of Arbitration Studies
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• v.7 no.1
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• pp.3-18
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• 1997