• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.162-171
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• 2023

In this study, The details for a seismic adapter designed to easily connect concrete structures and reinforcement materials for the in-plane reinforcement of aged structures were proposed. Proposed seismic adapter was tested for performance using a dynamic simulation on a 2-story column-beam structure, scaled to half of the real size. The experimental results showed that the reinforced test specimens using the seismic adapter improved their energy dissipation capacity by 3.5 times compared to the non-reinforced specimens. It was confirmed that the seismic adapter experienced no damage within its general usage range, thus proving its effectiveness. Subsequently, upon loading until the limit of deformation (a deformation angle of 3.3%), it was observed that one of the M10 bolts connecting the adapter and the reinforcement at the lower part of the first floor broke. Considering this finding, when applying seismic retrofitting in real situations, emphasis should be placed on the design of the bolts and anchors connecting the seismic adapter. This aspect warrants further research for validation.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.522-526
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• 2010

Heat storage application techniques can be categorized into the sensible heat storage and the latent heat storage according to the method of heat storage. Heat storage is the way of saving remaining heat when heating and cooling loads are light, and then using it when the heating and cooling loads are heavy. Latent heat storage is defined as the method of saving heat by using substances which have high potential heat when phase change is in the range of a certain temperature and when heat storage space is small, compared to those of sensible heat storage and it is possible that absorption and emission of heat at a certain temperature. This study is conducted to save energy when either air-conditioning or heating is operated in a building. We have tried to find out the essential properties of matter and the optimum mixing rate about cement and gypsum for building materials, which have been widely used for proper phase change materials (PCM), when thermal environment property is applied. So we obtained the result of the cooling delay effect about 19% with heat storage mortar containing 3 wt% of PCM.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.84-91
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• 2019

Recently, there has been a tendency to improve seismic performance of building structure by installing a steel hysteretic damping device which is economically efficient and easy to install and maintain. However, for a reinforced concrete building, a set of complicated connecting hardware and braces to fix the steel hysteretic damping device yields deteriorated reliability in damping performance. Therefore, this study presents a method of directly embedding a Kagome damper, which was investigated in previous researches, into a concrete structure without additional connecting hardware. Moreover, in this study, a series of experiments conducted to provide a basis of the Kagome damper by confirming the seismic behavior for various embedded lengths. As a result, in a group of the embedded length of $1.0l_d$, the dampers were pulled out, while concrete breakout occurs. In a group of $2.0l_d$, neither pull-out nor concrete breakout occurred, while the dampers show stable behavior. Moreover, the buried length of $2.0l_d$ has 1.3 times better energy dissipation capacity. The system presented in this study can reduce the cost and period for installing, omitting making additional hardware.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.13-22
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• 2018

In this study, seismic performance of existing RC frames reinforced with steel chevron bracing systems was experimentally evaluated. For this purpose, the unreinforced base specimen and seismically reinforced specimens with steel chevron bracing systems were fabricated and tested. Both strength and stiffness of the reinforced specimens were targeted about 2-3 times larger than the base specimen. Test results showed that the stiffness, strength, and ductility of the reinforced specimens considerably improved than those of unreinforced base specimen. Therefore, the results from this study could offer the basic information on the developing design guideline for the seismic reinforcement of RC frames.

• KIEAE Journal
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• v.13 no.6
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• pp.45-53
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• 2013

For the target goal of Zero-energy House construction in 2025, the government announced that the insulation regulations will be continuously enhanced. It has been predicted that high-performance insulation materials, such as vacuum insulation panel (VIP), should be used to decrease the thickness of outer walls. The aim of this study was to evaluate the performance of adhesively fixed external insulation and finish system (EIFS) with VIP. The energy performance of a base model with conventional internal insulation system and three alternatives of EIFS with VIP were analyzed by three-dimensional heat transfer simulation. Construction cost and convenience of each alternative were also evaluated and compared. As results, effective alternatives in terms of each performance as well as overall performance considering the weighting factors of each performance were suggested.

• KIEAE Journal
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• v.11 no.6
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• pp.101-108
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• 2011

The weather data has important role for performative building design. If the data location is close to building site, the result of performative design can be accurate. The data which have used nowadays in Korea are from U.S. Department of Energy (DOE) and Korea Solar Energy Society (KSES) but they cover only several locations in Korea which are 4 in DOE and 11 in KSES and there are opinions which it could be served building design efficiently even if the data are not enough. However the weather data for micro-climate are exist which are Green Building Studio Virtual Weather Station (GBS VWS) and Meteonorm weather data. Each weather data has different generation methods which are TMY2, TRY, MM5, and extrapolation. In this research, the weather date for climate are compared with DOE and KSES to check correlation. The result shows the value of correlation in Dry Bulb Temp. and Dew Point Temp. is around 0.9 so they have high correlation in both but in Wind Speed case the correlation(around 0.2) is not exist. In overall result, the data has correlation with DOE and KSES as the value of correlation 0.648 of GBS VW and 0.656 of Meteonorm. Even if the correlation value is not high enough, the patterns of difference in each weather element are similar in scatter plot.

• KIEAE Journal
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• v.14 no.3
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• pp.79-86
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• 2014

Studies have shown that the thermal performance of buildings changes depending on the year of construction completion. It leads to increased energy consumption of buildings and significant financial burden on users. Thus, this study has calculated the thermal insulation performance of 86 apartments quantitatively, using temperature difference ratio and sensible heat flux. Also, energy consumption characteristics depending on the year of construction completion and thermal insulation performance were analyzed by comparatively analyzing the results of insulation performance evaluation and heating costs. The analysis results are as follows. As for thermal insulation performance, it was around 70% lower in the apartments completed before 1985, compared to apartments completed after 2010. As for heating costs, the apartments with the highest heating cost incurred 1.5 higher heating cost than the apartment with the lowest heating cost. In terms of the insulation performance evaluation, the difference was 2.5-fold.

• Land and Housing Review
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• v.11 no.3
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• pp.69-74
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• 2020

Since the design Standard for Energy Conservation in Building was implemented in 2008 for the first time, building elements such as window and door should satisfy the minimum criteria to apply for a building. Though its regulation does not cover the whole building yet, recent demand to reduce energy consumption in building sector grows rapidly year by year and also draws a lot of interest to ensure the whole building level. For example, a Zero energy building, one of low-energy buildings, requires a customized solution to resolve the air leakage issue to meet the standards in achieving the high level of air tightness. In this study, six non-residential buildings were tested by fan pressurization method to observe the air tightness of whole building to suggest the construction guideline for air tightness of low-energy building. Five out of six tested buildings showed 0.27 to 1.16 h^-1 of number of air changes except one community center. These buildings were carefully constructed not only for building planning but also for parts where there was a concern of air leakage, thereby securing high levels of air-tightness. The construction skills were developed as a checklist to manage and supervise the construction site. It is our suggestion to use this checklist at construction sites for ZEB with the high level of air-tightness.

• KIEAE Journal
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• v.3 no.2
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• pp.51-58
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• 2003

The purpose of this study is to present rational methods of multi-criteria optimization of the shape of energy saving buildings. The object is to determine the optimum dimension of the shape of a building, based on the following criteria: minimum building costs (including the cost of materials and construction) and yearly heating costs. Mathematical model described heat losses and gains in a building during the heating season. It takes into consideration heat losses through wall, roof, floor and windows. Particular attention was paid to have a more detailed description of heat gains due to solar radiation. On the assumption that shape of building is rectangle in order to solve the problem, the proportions of wall length and building height are determined by using non-linear programing methods(Kuhn-Tucker Conditions). The results constitute information for designers on the optimum proportions of wall lengths, height, and the ratios of window to wall areas for energy saving buildings.

• 월간 기계설비
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• s.119
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• pp.71-83
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• 2000

점차 복잡해지고 있는 사회적 욕구를 만족시키기 위한 건물에서는 반드시 복잡한 설비가 요구되고 있고, 이러한 설비시스템 중에는 급수, 급탕 및 배수설비라고 하는 배관시스템이 없다면 기능유지에 막대한 지장을 초래할 것은 자명하다고 하겠다. 이러한 배관시스템에서는 항시 또는 일부 사용되어질 물이나 사용된 물이 흐르기 때문에 배관내부에 발생하는 스케일(scale)이나 슬라임(slime) 등은 피할 수 없는 사실인 것이다. 건축물 내에 설치된 각종 배관은 건물의 기능을 유지하고 보건위생과 직결되는 중요한 기능을 담당하고 있어 세척의 필요성이 매우 높음에도 불구하고 배관의 수명이 다할 때까지 거의 세척이 이루어지지 않고 사용되어 왔다. 이들 배관에 대한 세척은 배관의 수명연장과 관마찰 계수를 낮추어 급수의 수송동력을 절감할 수 있고, 난방관의 열전달 효과를 높여 에너지 절약 효과를 거두어 건물의 유지관리 비용 절감에 기여할 수 있음에도 적절한 세척공법이 개발되지 않고 있다. 이러한 관점에 맞추어 건물배관의 특성에 맞도록 고압 세척장치를 개발하고 이를 이용한 세척공법을 적용하고자 하였다. 즉, 배관 내에 압축공기를 주기적으로 분사하여 맥동현상이 일어나도록 하면서 기포를 발생시켜 기포가 관의 내벽에서 성장하여 파괴될 때 관내에 부착된 이물질을 제거할 수 있고, 또한 세척효과를 높이기 위하여 관의 벽면에 접촉하면서 배출되는 과정에서 이물질을 제거할 수 있도록 구조와 아울러 이들 장치를 이용한 세척방법의 적용성에 대해서 고찰하고자 한다.