• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.129-130
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• 2023

The compressive strength of concrete is greatly affected by the temperature inside the concrete at the initial age immediately after pouring. In the KCI Concrete Standard Specification, only the temperature correction strength (Tn) according to the curing temperature is applied in the mixing strength calculation formula, and mSn is not considered. The formula based on the Chrino model of the blast furnace slag concrete was calculated, and the strength of the structural concrete and the strength of the water cured specimen in the same mixture were compared with the predicted strength. As a result, the error between the predicted strength and the measured strength was greater in the structural concrete than in the concrete specimen.

• 한국공간정보시스템학회 논문지
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• 제4권2호
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• pp.65-74
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• 2002

오늘날 정보시스템을 구축하는 모든 분야에서 컴포넌트에 기반한 개발(CBD : component based development) 방법이 주 흐름으로 등장하였다. GIS 영역에서도 컴포넌트의 개발 및 조립을 통한 시스템 구축을 권장하고 있다. GIS 영역은 다른 영역에 비하여 컴포넌트의 식별이 뚜렷한 업무영역(business domain)을 비교적 많이 가지고 있다. 이 영역은 비교적 산술적 기능을 많이 요구하는 부분이다. GIS 영역에서나 전사적(enterprise) 영역에서나 비산술적 기능 부분이 많이 존재함을 인식하여야 한다. 컴포넌트는 재사용성을 보장하여야 하는 특징을 가지고 있다. 재사용성이란 가능한 기능이 단순하고 최소의 크기를 가질 때 효용가치가 상승한다. 본 연구에서 GIS 컴포넌트를 추출하는 기법을 제시한 바가 있다. 본 연구에서는 친화력분석(affinity analysis)이란 기법을 통하여 GIS 컴포넌트를 추출하고자 한다. CBD에서는 UML을 활용하는 것이 기본으로 쓰임새(use case) 와 클래스는 UML의 핵심을 이루는 요소이다. 이 쓰임새와 클래스가 해당 업무영역 내에서 얼마나 친화력을 가지는가를 살펴보는 것이 친화력 분석의 목적이며, 이 분석 결과를 가지고 컴포넌트를 식별하게 된다. 이 친화력 분석은 GIS 영역뿐만 아니라 모든 업무영역에 활용이 가능하고 분석의 수행 절차가 복잡하지 않음으로 널리 활용할 수 있을 것으로 사료된다.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2006년도 추계학술발표대회 논문집
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• pp.275-280
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• 2006

The protection of the environment is one of today's key demanding international activities and interests. All of aspects including industry, economy and society should be changed into environmental friendly industries. The building is not exception in this trend. What is not generally realized is that building, in the lifecycle of construction, use and demolition, account for large construction, not considered with environment impact and conservation in the lifecycle. Expecially, the construction materials and components used in the construction stage has much embodied energy. And much $CO_2$ emit on the production of the construction material and component. The energy use and $CO_2$ emission would continuously diminish the limited natural resources and impact the environment such as ozon layer destruction. In this paper, it studied the estimation of the amount of energy use and $CO_2$ emission in the building construction stage, it would provide the estimation process and applied with the multifamily housing.

• 한국건축시공학회지
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• 제13권5호
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• pp.457-464
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• 2013

Traditionally, the material used for the form in reinforced concrete construction has been wood or steel. But recently, aluminum forms have been widely used in wall structures such as apartment buildings. Aluminum is light, easy to handle, and economically advantageous, but the hydrogen gas created due to its reaction with the alkali component in concrete gives rise to air pockets on the concrete's surface, and deteriorates the surface's finishability. In this research, to determine the influence of aluminum material on concrete, the cement paste W/C and its chemical reactivity in alkali and acid solution were analyzed. As a prevention plan, the influence of the number of applications of calcium hydroxide and various surface coating materials was analyzed. Through the analysis, it was found that the surface voids on the aluminum form are the result of the reaction of hydrogen gas with an alkali such as $Ca(OH)_2$. This can be prevented by the surface treatment of $Ca(OH)_2$, separating material and coating material. However, poor surface form and damages to the form are expected to cause quality degradation because of the aluminum-concrete interaction. Therefore, thorough surface treatment, rather than the type of separating material or coating material, is considered the most important target of management.

• ETRI Journal
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• 제38권4호
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• pp.735-745
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• 2016

The Paris agreement at the 21st Conference of the Parties (COP21) emphasizes the reduction of greenhouse gas emissions and increase in energy consumption in all areas. Thus, an important aspect is energy saving in buildings where the lighting is a major component of the electrical energy consumption. This paper proposes a building energy management system employing visible light communication (VLC) based on LED lighting. The proposed management system has key characteristics including personalization and localization by utilizing such VLC advantages as secure communication through light and location-information transmission. Considering the efficient implementation of an energy-consumption adjustment using LED luminaires, this paper adopts variable pulse position modulation (VPPM) as a VLC modulation scheme with simple controllability of the dimming level that is capable of providing a full dimming range. This paper analyzes the VPPM performances according to variable dimming for several schemes, and proposes a VPPM demodulation architecture based on dimming-factor acquisition, which can obtain an improved performance compared to a 2PPM-based scheme. In addition, the effect of a dimming-factor acquisition error is analyzed, and a frame format for minimizing this error effect is proposed.

• 한국공간구조학회논문집
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• 제13권1호
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• pp.97-104
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• 2013

Recent tall buildings tend to have unconventional shapes as a prevailing, which is effective for suppressing across-wind responses. Suppression of across-wind responses is a major factor in tall building projects, and the so called aerodynamic modification method is comprehensively used. The purpose of the present study is to investigate the pressure fluctuations on tapered and setback tall buildings, including peak pressures, power spectra and coherences through the synchronous multi-pressure sensing system techniques. And flow measurements around the models were conducted to investigate the condition of vortex shedding. The results show that by tapering and setback, different distributions of mean pressure coefficients at leeward surface were found, which is caused by the geometric characteristics of the models. And the power spectra of wind pressures at sideward surface become wideband and the peak frequencies are different depending on heights, which makes the correlation near the Strouhal component low or even negative. The differences in shedding frequencies were also confirmed by the flow fields around the models.

• 한국농촌건축학회논문집
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• 제22권3호
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• pp.33-40
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• 2020

Wood is one of the main materials of wooden building. Hanok also uses wood as its main component. Recently, Hanok continues to be built. Wood is affected by the climatic environment. The growth of decay bacteria is activated at more than 80% relative humidity. The microclimate environment and moisture content were measured for architectural cultural properties that have been maintained for a long time as a wooden building. The method analyzed the measured data by distinguishing between cloudy and sunny days. In the case of the old house, Anchae moisture content was higher than that of Sarangchae. This seems to be due to the narrow front yard or the planting of trees. The microclimate environment inside the house began to decrease in humidity from 8 am. According to the survey data, the relative humidity was less than 80% from 9 am when there was wind around 4-6 am. It appeared an hour earlier than in the absence of wind. As a result, the time interval for dehumidifying of wood was widened. Therefore, the wooden building is open to the front so there is airflow under the eaves during the daytime and wind in the morning appear to be alternatives in order to lower the moisture content.

• Structural Engineering and Mechanics
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• 제65권6호
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• pp.751-760
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• 2018

Damages in concrete structures due to aging and other factors could be a serious and immense matter. Making the best selection of the most viable and practical repairing and strengthening techniques are relatively difficult tasks using traditional methods of structural analyses. This is due to the fact that the traditional methods used for assessing aging structure are not fully capable when considering the randomness in strength, loads and cost. This paper presents a reliability-based methodology for assessing reinforced concrete members. The methodology of this study is based on probabilistic analysis, using statistics of the random variables in the performance function equations. Principles of reliability updating are used in the assessment process, as new information is taken into account and combined with prior probabilistic models. The methodology can result in a reliability index ${\beta}$ that can be used to assess the structural component by comparing its value with a standard value. In addition, these methods result in partial safety factor values that can be used for the purpose of strengthening the R/C elements of the existing structure. Calculations and computations of the reliability indices and the partial safety factors values are conducted using the First-order Reliability Method and Monte Carlo simulation.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.121-126
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• 2009

This study analyzed the standard school's energy usage and patterns as the zero-energy goal of primary school building, and proposed the energy reduction process of school building using energy analysis computing simulation tool. As a analysis simulation tool, Visual DOE 4.0 is used. For analysis of actual energy usage, selected primary school that is standard in the nation's energy consumption. Standard of the school's energy consumption analysis were devided into electric and gas energy. Input parameters of the simulation program based on the literature material and field survey material. after, but it was calibrated to comparison with the standard school's energy consumption. Finally, its energy usage analyzed by component and made the priority order of energy saving. Applied energy saving technologies are envelopment insulation, high efficiency lighting, high performance HAVC system and used active equipment system of solar collector and photovoltaic generation for additional savings.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.275-280
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• 2008

Photovoltaic(PV) permit the on-site production of electricity without concern for fuel supply or environmental adverse effects. The electrical power is produced without noise and little depletion of resources. So BIPV(Building-Integrated Photovoltaic) system have been increased around the world. Hereby the relative installation costs of the system will be relatively low compared to traditional installations of PV in high-rise buildings. This paper examined possibility of BIPV system of cold facade type and analyzed of performance of BIPV system of cold facade type. The system is influenced by conditions such as irradiation, module temperature, shade and architectural component etc. If this BIPV system of 1.1kW is possible the natural ventilation in the summer case, the temperature of PV module decrease and then the efficiency of PV system increase generally. By the results, the annual averaged PR of BIPV system of cold facade type is about 73.1%.