• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.175-180
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• 1999

The heating system of korea apartment house is called Ondol. The surface finishing mortar of this floor system typically used the cement based mortar, where the surface finishing mortar easily appears the crack. To order to crack control, the cement that added expansive additive used to reducing dry-shrinkage. For the surface finishing mortar, the types of shrinkage is known as plastic shrinkage, dry-shrinkage and autogenous This experimental study is to investigate the difference on dry-shrinkage of the cement that added expansive additives and OPC. The test method is varied the ration of water/cement (W/C) and the ratio of sand/cement(S/C). For OPC, The increase of the ratio of S/C is reduced dry-shirnkage but for the cement that added expansive additives, the increase of the ratio of S/C is augmented dry-shrinkage For OPC, The increase of the ratio of W/C is augmented dry-shrinkage but for the cement that added expensive, the increased of the ratio of W/C is reduced dry-shrinkage.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.173-176
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• 2000

The objective of this paper is to investigate the properties of strength and thermal conductivity of floor cement mortal using copper fiber. Compressive strength thermal conductivity and length change are tested. According to the experimental results, compressive strength, thermal strength and thermal conductivity of mortar using copper finer are shown to be increased with increase of the contents of copper fiber and the aspect ratio. In case of length change of cement mortar using copper fiber also shows deline tendency compared with that of plain mortar.

• The Journal of the Acoustical Society of Korea
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• v.27 no.4
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• pp.163-170
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• 2008

Most of receiving rooms for the measurement of floor impact sound have rectangular shapes with couple of meters of dimension, with reflective finishing, no furniture, no curtains. Modal overlaps in those condition are the major reason for the low reproducibility, and as a matter of course, the low credibility. It is the major purpose of this study that searching for a better measurement method which mitigate the effect of modal overlap on measurement. Two ways of methods are tested. One is the way described in ISO standards which enables controlling the room modes of receiving rooms, the other is the way which enables to get more precise spatial averages in receiving rooms with room modes. It is not easy maintaining the reverberation time of low frequency bands in the range between 1s and 2s, though it is proven to be effective controlling the room modes with base traps. Space-time average SPL's through combinations of rotating microphones are easy to measure, and have good consistencies with average SPL of entire receiving room.

• Journal of KIBIM
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• v.12 no.1
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• pp.42-54
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• 2022

BIM facilitates data transparency and consistency through three-dimensional parametric modeling and promotes the accurate managing and sharing of project information. In Korea, however, BIM-based detailed design of architectural interior finishes required during the Construction Documents phase increases the burden on architectural firms due to frequent design changes and manual workload. Therefore, the purpose of this study was to establish rule-based modules using parametric modeling that automates repetitive tasks that occur during the detailed design of interior finishing. Interviews with practitioners were conducted to analyze the major finishing elements. Of these floors, walls, and ceilings, which were the most rudimentary and common items, were selected as the subjects of the study. The modules developed in this study have two functions. One is to create new finish types, and the other is the automatic modeling of new types into rooms. For these functions, parameters that belonged to each finish and room element in a BIM model were analyzed and valid parameters directly used for parametric modeling were derived. Then, based on these parameters, rule-based modules for three elements, I.e., floors, walls, and ceilings were constructed with Revit Dynamo, and the effectiveness of the modules was verified with a pilot test. In conclusion, this study suggested a series of processes for automatic finishing to improve the efficiency of BIM-based architectural detailed design of finishes and to contribute in solving the chronic problems occuring during current design processes.

• Korean Journal of Construction Engineering and Management
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• v.23 no.2
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• pp.95-101
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• 2022

This study attempts to identify the ways of reducing the floor impact sound, by applying six different types of the reinforced bar girders and stirrup arrangements to the Structure: (1) the longer-direction girder arrangements (2) the shorter-direction girder arrangements (3) the diagonal-direction arrangements (4) the longer-direction girder arrangements with stirrups (5) the shorter-direction girder arrangements with stirrups (6) the diagonal-direction arrangements with stirrups. In order to identify the most effective structural changes, each slab was tested with bang machines, measuring the level of the sound impact. The results showed that the longer-direction girder arrangements with stirrups were the most effective one. In addition, the effectiveness of slab was found to be remarkable, showing the level of minimum 1dB to maximum 5dB, where the slab was compared with the control models without girders and stirrups. In conclusion, it is suggested that the longer-direction girder arrangements with stirrups could possibly be applied to the Wall Structures to minimize the floor impact sound.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.82-88
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• 2013

In this project a preliminary experimental research work was done to apply mortars containing magnetite as fine aggregates unto floor finishing materials in order to make indoor environment eco-friendly and to have noiseproof control between floors. Crushed magnetites were substituted as sands in the mix design with a range of 0, 20, 40, 60, 100%. First far-infrared radiation tests to determine emissivity and emission power were done in accordance with the KICM test standard and an outstanding result was obtained. Density and compressive strength test results also showed that as the substitution increases, test values increase in a linear trend. However dry shrinkage test results revealed that as the substitution increases, shrinkage strain also increases. To clearly seek a solution about this problem, more experimental works should be done on oncoming experimental program.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.10-18
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• 2019

The Interior finishing materials tried to evaluate the combustion characteristics and the dangerous characteristic of Floor finish and Wall finish. We often use, conducting the experiment ISO 5660-1, Cone Calorimeter method, and ISO-TR-9122 FT-IR. According to the result of Cone calorimeter experiment, the tile carpet FF3 of Floor material had the highest THR $74.6mj/m^2$ because of the highest risk, and the PHRR of FF1 was $726kW/m^2$, which was easy to bum. As a result FT-IR test, The CO, $CO_2$ ratio was 8,146 PPM for roll carpet FF1 than tile carpet FF2, FF3 5,996, 5,171 PPM, which was a carpet with a high toxicity risk. In the case of wall finishes, The MDF plate(WF3) was THR $86.7mj/m^2$ with a high risk, PHRR $384kW/m^2$ was easy to ignite and toxicity index was 5.5. The CO, $CO_2$ ratio was 1,340~8,596 PPM, But the WF4 was the most toxic with 8,596 PPM.

• Korean Journal of Construction Engineering and Management
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• v.23 no.5
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• pp.87-97
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• 2022

Although the use of BIM in architectural projects has increased, repetitive modeling tasks and frequent design errors remain as obstacles to the practical application of BIM. In particular, interior finishing elements include the most varied and detailed requirements, and thus requires improving its modelling efficiency and resolving potential design errors. Recently, visual programming-based modules has gained traction as a way to automate a series of repetitive modeling tasks. However, existing approaches do not adequately reflect the practical modeling needs and focus only on replacing siimple, repetitive tasks. This study developed and evaluated the performance of three modules for automatic detailing of walls, floors and ceilings. The three elements were selected by analyzing the man-hours and the number of errors that typically occur when detailing BIM models. The modules were then applied to automatically detail a sample commercial facility BIM model. Results showed that the implementations met the practical modeling requirements identified by actual modelers of an construction management firm.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.67-70
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• 2010

This study investigates the physical properties of the acrylic emulsion mortar according to variable composition set of redispersible emulsion powders. This materials have to be composed of many types of binders and chemical additives. So it is difficult to decide suitable mixing proportion of composition materials. The redispersible emulsion powders using "2, 4, 6, 8kg" of EVA polymers dispersion ranges are prepared with acrylic emulsion mortars and were tested for basic characteristics such as flexural, and compressive strength, wheel load. Through experiments we found that the improved formula to satisfy the standard of wheel load by EVA polymers, and the masration rangs between about 2.0% to 2.6% which the white portland cenmet and EVA polymers is good for resistauce wheel load.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.293-296
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• 2001

1990년대 중반 이후 우리나라 초등학교 교실은 열린교육과 다양성을 추구하는 새로운 열린교실을 표방하고 진행되고 있다. 또한 건축설계에 있어서도 과거의 종합 표준설계에 의하지 않고 각 학교마다 별도의 건축설계에 따라 지어지고 있다. 본 논문의 목적은 현재의 초등학교 교서의 차음환경을 조사하고 새로이 지어진 교사의 교실과 열린교실의 실내 음환경을 조사하여 현재 상황을 분석평가하고 이에 대한 대안을 제시하고자 하는 것이다. 이를 위하여 건축시공연대가 다른 초등학교 3개 학교를 선택하여 단위교실에서의 실내음향인자(RT60, C80, D50, RASTI)와 인접교실과의 차음성능(TL)을 측정하였다. 또한 해당교실의 학생과 교사에 대하여 설문조사를 실시하였다. 각 측정은 외부와 복도에 인접한 창문의 개폐여부와 실내의 위치별로 이루어 졌다. 실험결과, 열린교육에 따라 가변적 교실의 구성은 기존의 교실보다 차음성능이 평균$5\sim6dB$ 낮은 것으로 나타났다. 또한 신축교사의 RASTI값(0.73)이 10년 이상 된 학교(0.70)나 열린교실(0.64)보다 높은 것으로 나타났다. 음성명료도(D50) 역시 일반 신축교사가 열린교실 보다 높게 나타났다. 이것은 실의 기밀과 내부바닥의 마감자재로 비롯되었으며 최근의 열린교실은 음의 차음과 실내명료도에서 열악한 것으로 결론되었다.