• Architectural research
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• v.15 no.4
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• pp.201-206
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• 2013

Special attention is required for the design of windows due to their high thermal vulnerability. This paper examines the problems that might arise in the application of the u-value, by reflecting the changes in the u-value of the window, depending on the window-to-wall ratio obtained in an energy demand analysis. Research indicates that the u-value of a window increases with an increase in the difference between the u-values of the frames and the glass. Relative to the changes in the u-value of the windows, the energy demand varied from 1.3% to 9.3%. Windows with a g-value of 0.3 or 0.5 displayed a higher energy demand than windows with a g-value of 0.7. Therefore, when the difference between the performance of the glass and the frame is significant, especially when the g-value is small, a modified heat transmission coefficient should be applied to the window size during the evaluation of the building energy demand.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.2
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• pp.32-43
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• 1997

Abstract A series of permeability tests was performed on the mixtures with specific mixing rates of sand and bentonite using modified rigid-wall permeameter. Sand-bentonite mixtures were permeated by organics, ethanol and TCE. Permeability of bentonite with several mixing rates had a tendency to decrease up to initial one pore volume and permeability was thereafter converged to a constant value. When sand-bentonite mixtures was permeated by water, permeability was decreased at the beginning but it was thereafter converged to a constant. Among several mixing rates, permeability was greatly decreased at 15% of mixing rate. When sand-bentonite mixtures with 15% mixing rate was permeated by ethanol, permeability was about 10 times larger value than permeability of water. Peameability was shown greater values when permeated by TCE (TrichloroEthylene) followed by ethanol. Suitable mixing rate of sand-bentonite for a liner of waste landfills was detected.

• Journal of ILASS-Korea
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• v.8 no.1
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• pp.1-8
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• 2003

The flow analysis of the axial fan of rotary burner was performed by SIMPLE(Semi Implicit Method for Pressure Linked Equations) algorithm and finite volume mothod performed in the case of 3-D, incompressible, turbulent flow. In this study, the coordinate transformation was adapted for the complex geometry of axial fan, and the standard $k-{\varepsilon}$ model and wall function method were used for analysis of turbulent flow. Multi-block grid system was used for flow field and divided into four domains such as the inlet, outlet, flow field of rotating vane, and tip clearance. Fan rotation was simulated by rotational motion using MRF(Multiple Rotating Reference Frame) in steady, incompressible state flow.

• Journal of Korean Association for Spatial Structures
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• v.20 no.1
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• pp.87-94
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• 2020

A corrugated steel plate wall (CSPW) system is advantageous to secure the strength and stiffness required for lateral force resistance because of its high out-of-plane stability. It can also stably dissipate large amounts of energy even after peak strength. In this paper, a preliminary study has been carried out to use the CSPW system in the seismic retrofit of existing reinforced concrete (RC) moment frame buildings. The seismic performance for an example building was evaluated, and then a step-by-step retrofit design procedure for the CSPW was proposed. An equivalent analytical model of the CSPW was also introduced for a practical analysis of the retrofitted building, and the strengthening effect was finally evaluated based on the results of nonlinear analysis.

• 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.1
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• pp.54-61
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• 2004

The purpose of this study is to improve of energy performance in school buildings. Many building renovations have mainly focused on commercial buildings and houses, but school buildings have no attention in this field although there are many buildings that show degraded energy performance and there are many old fashioned buildings which need renovation. This study was carried out through the survey, field study, energy simulation and life cycle cost analysis. The results of this study can be summarized as follows: In model building, large amount of heat were lost at the building envelope, such as non-insulated skins, window-sills and window-frame joints. According to the simulation result, about 15％ of heating energy is saved by the insulating works compared to pre-renovation condition. Also, LCC analysis revealed to be more effective to select a exteria wall insulation such as a dryvit system.

• Journal of the Korea Furniture Society
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• v.24 no.3
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• pp.302-308
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• 2013

To collection of field data for development of maintenance manual of Han-ok, we investigated defects which occurred in members of Han-ok by field investigation. The noticeable defects were wood cracks, gaps that developed between wood pillar and wall or wood window frame and tenon joints. The most common biological defect was blue stain which was created in log. The mold generation was observed on exterior wood and wall which get wet by precipitation. The gaps between members of Han-ok pointed out as defect that is urgently improved by residents of Han-ok. The reason is mainly due to poor of insulation in winter by bad confidentiality. The maintenance work of defect such as gap was conducted personally. As a result, the repair parts were ugly for unfamiliar repair work.

• Transactions of Materials Processing
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• v.22 no.8
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• pp.486-491
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• 2013

A numerical investigation of the butting process for an AZ31B magnesium alloy tube at elevated temperatures was conducted to develop a double-butted magnesium alloy tube. As a result of the current study, it was found that the amount of doming of the tube end, prior ironing-extrusion to obtain high wall thickness reduction are important factors for the butting process of magnesium alloy tubes. There is also a limitation of the thickness profile of butted tube due to buckling of tube wall during the stripping stage.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.845-850
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• 2000

This paper presents the results of tests performed on the transfer girders which have been generally used between upper walls and lower frames in the hybrid structures. The 8 specimens were designed using (1) ACI method, (2) strut-tie model, and (3) X-type shear reinforcement cage. The capacities of the specimens are in general larger than the design values except the one designed according to strut-tie model. The reason for this difference seems to be due to the arbitrary allocation of transferred shear force to the path of direct compression strut and the path of indirect strut and tie. The failure modes turn out toe be (1) shear failure at critical shear zone, (2) compressive concrete crushing in the diagonal strut in the shear zone of transfer girder, and (3) compressive concrete crushing in the corner of upper wall.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.275-278
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• 2005

High performance fiber reinforced cement composites(HPFRCCs) is a class of high ductile fiber reinforced cementitious composites developed for applications in the sensitive construction industry. HPFRCCs has undergone major evolution in both materials development and the range of emerging applications. This paper is to evaluate structural strengthening performance of LRCF(Lightly reinforced concrete frame) using the HPFRCCs. The experimental results, as expected, show that the crack load, yield load, and limited load are superior for specimen with HPFRCCs infill wall due to crosslink effect of fibers in concrete.