• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.529-536
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• 1999

The objective of the research stated herein is to observe th elastic and inelastic behaviors and ultimate capacity of 1 : 5 scale 3-story reinforced concrete frame. Pushover tests were performed to 1:5 scale 3-story reinforced concrete frames without and with infilled masonry. To simulate the earthquake effect, the lateral force distribution was maintained to be an inverted triangle by using the whiffle tree. From the results of tests, the relations between the total lateral load and the roof drift, the distribution of column shears, the relation between story shear and story drift, and the angular rotations at the critical portions of structures were obtained. The effects of infilled masonry are investigated with regards to the stiffness, strength, and ductility of structures. Final collapse modes of structures with and without infilled masonry are compared.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.107-108
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• 2009

This is an experimental study on using the Honeycomb System show you the method of increasing ability of ductility and shear strength seismic performance to reinforced concrete column and masonry waist-high wall.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.99-100
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• 2009

In this paper, wish to achieve an experimental study to investigate enhanced performance of the masonry walls strengthened in shear and ductility using Aramid fiber strip.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.513-516
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• 2002

The flow structure and heat transfer characteristics of a turbulent buoyant jet were investigated experimentally. The instantaneous temperature and velocity fields in the near field were measured using a two-frame PIV and PLIF techniques. A thin light sheet illuminated a two-dimensional cross section of the buoyant jet in which Rhodamine B was added as a fluorescent dye. The intensity variations of LIF signal from Rhodamine B molecules scattered by the laser light were captured by a CCD camera after passing an optical filter. By ensemble averaging the instantaneous temperature and velocity fields, the mean temperature and velocity fields as well as the spatial distributions of turbulent statistics were obtained. The results show the flow structure and convective heat transfer of the developing shear layer in the near field.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.157-162
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• 2003

An experimental investigation was conducted to study the behavior of high-strength RC wide beam-column joints with slab subjected to reversed cyclic loads under constant axial load. Six half scale interior wide beam-column assemblies representing a portion of a frame subjected to simulated seismic loading were tested, including three specimens without slab and three specimens with slab. The primary variables were compressive strength of concrete($f_ck$=285, 460kgf/$cm^2$), the ratio of the column-to-beam flexural capacity($M_r$=$\Sigma M_c / \Sigma M_b$ ; 0.77 -2.26), extended length of the column concrete($l_d$ ; 0, 12.5, 30cm), ratio of the column-to-beam width(b/H ; 1.54, 1.67). Test results are shown that (1) the behavior of specimen using high-strength concrete satisfied for required minimum ductile capacity according to increase the compressive strength, (2) the current design code and practice for interior joints(type 2) are apply to the wide beam-high strength concrete column.

• Steel and Composite Structures
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• v.22 no.1
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• pp.183-201
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• 2016

Perforated steel beams can be optimised by increased beam depth and the moment of inertia combined with a reduced web thickness, favouring the use of original I-section beams. The designers are often confronted with situations where optimisation cannot be carried out effectively, taking account of the buckling risk at web posts, moment-shear transfers and local plastic deformations on the transverse holes of the openings. The purpose of this study is to suggest solutions for reducing these failure risks of tested optimal designed beams under applying loads in a self-reacting frame. The design method for the beams is the hunting search optimisation technique, and the design constraints are implemented from BS 5950 provisions. Therefore, I have aimed to explore the strengthening effects of reinforced openings with ring stiffeners, welded vertical simple plates on the web posts and horizontal plates around the openings on the ultimate load carrying capacities of optimally designed perforated steel beams. Test results have shown that compared to lateral stiffeners, ring and vertical stiffeners significantly increase the loadcarrying capacity of perforated steel beams.

• Design & Manufacturing
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• v.12 no.1
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• pp.26-30
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• 2018

The aluminum chassis drive gear manufacturing process improvement has been very effective in both technical and economic aspects. Technology for Shear mold design technology, mold material selection and processing technology, and press molding technology has improved greatly overall. In the meantime, it is necessary to clarify the causes of defects that occur frequently due to lack of technology, Based on this, it is meaningful that it has secured the ability to respond to new product development and molding in the future. By applying these technologies, we plan to expand not only the drive gear chassis, but also various types of press forming such as frame, handle, various fastening parts of system window. In addition, the ability to develop precision products in the future is expected to become a driving force in further enhancing the competitiveness of companies.

• Earthquakes and Structures
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• v.9 no.6
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• pp.1291-1311
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• 2015

This study investigates the seismic energy dissipation capacity of a hybrid passive damper composed of a friction and a hysteretic slit damper. The capacity of the hybrid device required to satisfy a given target performance of a reinforced concrete moment resisting frame designed with reduced design base shear is determined based on the ASCE/SEI 7-10 process, and the seismic performances of the structures designed without and with the hybrid dampers are verified by nonlinear dynamic analyses. Fragility analysis is carried out to investigate the probability of a specified limit state to be reached. The analysis results show that in the structure with hybrid dampers the residual displacements are generally reduced and the dissipated inelastic energy is mostly concentrated on the dampers. At the Moderate to Extensive damage states the fragility turned out to be smallest in the structure with the hybrid dampers.

• Earthquakes and Structures
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• v.10 no.6
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• pp.1273-1289
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• 2016

This paper addresses the concept of lateral overstrength; the ratio of actual lateral strength to design base shear force, for both SDOF and MDOF systems considering soil structure interaction. Overstrength factors are obtained with inelastic time history analysis for SDOF systems for period range of 0.1-3.0 s, five different aspect ratios (h/r=1, 2, 3, 4, 5) and five levels of ductility (${\mu}$=2, 3, 4, 5, 6) considering soil structure interaction. Structural overstrength for MDOF systems are obtained with inelastic time history collapse analysis for sample 1, 3, 6, 9, 12 and 15 storey RC frame systems. In analyses, 64 ground motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil are used. Also lateral overstrength ratios considering soil structure interaction are compared with those calculated for fixed-base cases.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.212-219
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• 1999

In this paper we investigated an applicability of earthquake regulations for seismic-isolated building structures which has been used currently and propose an efficient method for vertical distribution of seismic loads. The distribution of force is revised in UBC-94 as vertical distribution of force of UBC(Uniform Building Code)-91 is not sufficient safety but its distribution is inefficient expensive because of similar expression to fixed-based structures. In order to overcome this difficulties improved vertical distribution to fixed-based structures. In order to overcome this difficulties improved vertical distribution of seismic load is proposed using two degrees-of-freedom isolated structures and mode shape of fixed-based structures. Efficiency and accuracy of the proposed method are verified through analysis of an example structures with moment resisting frame and shear walls so this study approximate to dynamic analysis results in each case.