• 한국산학기술학회논문지
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• 제13권8호
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• pp.3307-3314
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• 2012

농어촌 주택 표준모델에 대한 연간 건물에너지요구량을 DesignBuilder를 사용하여 계산하였다. 실내설정온도, 외벽의 열관류율, 창호타입, 환기량을 변화시키며 건물의 설계/운영 변수들이 에너지요구량에 미치는 영향을 분석하였다. 건물의 크기와 상관없이 난방에너지요구량이 냉방에너지요구량보다 더 큰 것으로 나타났다. 단열재 두께를 증가시켜 외벽의 열관류율을 감소시키면 단열효과의 증가로 난방에너지요구량은 감소하지만 냉방에너지요구량이 증가한다. 하지만 외벽의 열관류율 조절을 통한 난방에너지요구량의 절감에는 한계가 있으므로 외부에 직접 노출된 외벽의 면적을 최소화하는 것이 더 효과적인 것으로 판단된다. 계산에 사용된 4가지 창호 중 일반 이중창호가 난방에너지요구량 측면에서 가장 유리한 것으로 나타났다. 침기량은 일정하게 유지하고 단위시간당 환기량을 증가시킨 경우 냉방에너지요구량은 큰 변화가 없었으나 난방에너지요구량이 증가하였다. 실내의 공기질이 만족되는 범위 내에서 환기량을 최소화하는 것이 연간 건물에너지요구량을 줄이는데 유리한 것으로 판단된다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.354-359
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• 2012

With the long-term use of fossil fuel, the whole world is suffering from serious abnormal changes in weather caused by global warming. For this reason, many countries are reducing greenhouse gas emissions out of obligation and the allowable emissions are assigned to each country. Korea is also putting much effort into reducing greenhouse gas emissions by 30 percent against BAU(Business As Usual) by 2020, and is pushing ahead with several projects such as 'Million Green Home' and 'Hatsal Gaduk Home' to expand the use of new renewable energy in house as part of its policy. This study was designed to come up with improvements and help to expand photovoltaic facilities, by investigating and analyzing the current state of photovoltaic facilities in the country and problems in installing them through an in-site reconnaissance and a survey in Jecheon area. As the result, it was found that residents in the area were inadequate to operate and install photovoltaic facilities, lacked awareness of them and felt burdened economically by managing and installing them, although they had a high awareness of solar energy and photovoltaic facilities are constantly increasing with governmental support. In conclusion, it is considered that as improvements, operational effects should be increased through development of techniques, factors to reduce the effects in operating them due to insufficient management and installation should be removed and awareness of residents need to be improved through long-term plans, political support and education of the government.

• Steel and Composite Structures
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• 제45권1호
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• pp.83-100
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• 2022

Timber is one of the few natural, renewable building materials and glulam is a type of engineering wood product. In the present work, timber-based braces are applied for retrofitting midrise Special Moment Resisting Frame (SMRF) using two types of timber base braces (Timber base glulam, and hybrid Timber-Steel-BRB) as alternatives for retrofitting by traditional steel bracings. The improving effects of adding the bracings to the SMRF on seismic characteristics of the frame are evaluated using load-bearing capacity, energy dissipation, and story drifts of the frame. For evaluating the retrofitting effects on the seismic performance of SMRF, a five-story SMRF is considered unretofitted and retrofitted with steel-hollow structural section (HSS) brace, Glued Laminated Timber (Glulam) brace, and hybrid Timber-Steel BRB. Using OpenSees structural analyzer, the performance are investigated under pushover, cyclic, and incremental loading. Results showed that steel-HSS, timber base Glulam, and hybrid timber-steel BRB braces have more significant roles in energy dissipation, increasing stiffness, changing capacity curves, reducing inter-story drifts, and reducing the weight of the frames, compared by steel bracing. Results showed that Hybrid BRB counteract the negative post-yield stiffness, so their use is more beneficial on buildings where P-Delta effects are more critical. It is found that the repair costs of the buildings with hybrid BRB will be less due to lower residual drifts. As a result, timber steel-BRB has the best energy dissipation and seismic performance due to symmetrical and stable hysteresis curves of buckling restrained braces that can experience the same capacities in tension and compression.

• Earthquakes and Structures
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• 제9권3호
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• pp.657-671
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• 2015

The level of ductility is determined by depending on the intended use of the building, the region's seismic characteristics and the type of structural system when buildings are planned by engineers. Major portion of seismic energy is intended to be consumed in the plastic zone in structural systems of high ductility, so the occurrence of damages in load bearing and non-load bearing structural elements is accepted in planning stage under severe earthquakes. However, these damages must be limited among specific values in order not to endanger buildings in terms of the bearing capacity. Isolators placed between the basement and upper structure make buildings behave elastically by reducing the effects of seismic loads and improving seismic performance of building significantly. Thus, damages can be limited among desired values. In this study, the effectiveness of seismic isolation is investigated on both fixed based and seismic isolated models of a hospital building with high ductility level with regard to lateral displacements, internal forces, structural periods and cost of the building. Layered rubber bearings are interposed between the base of the structure and foundation. Earthquake analysis of the building are performed using earthquake records in time domain (Kocaeli, Loma Prieta and Landers). Results obtained from three-dimensional finite element models are presented by graphs and tables in detail. That seismic isolation reduces significantly the destructive effects of earthquakes on structures is seen from the results obtained by seismic analysis.

• KIEAE Journal
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• 제11권2호
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• pp.75-82
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• 2011

In Korea, the ratio of population in urban areas used to be only 50.1% in 1970, but with the value risen to 90.8% in 2009, urbanization is going on rapidly. Urbanization, which occurs by the rampantly planted buildings, has become major source of raising building density, changing wind direction and reducing wind amount, and such reductions are affecting even inside the building. In each year, among the total energy consumption in Korea, residential portion takes up significant ratio, and specifically the ratio of apartment house is shown to be highest. In order to solve such problem, many studies are being conducted for the improvement of natural ventilation performance. The natural ventilation performance of apartment house are significantly determined by the characteristics of external and internal structure, but in macroscopic perspective, the performance is established fundamentally by the layout characteristics of the main building of the apartment house in preparation for wind conditions. So far researches on raising the thermal comfort through elevation of ventilation performance have been conducted actively, but many of them propose only theoretical concepts deduced through wind path analysis, and do not include any indicator to measure ventilation performance simply only with area data from layout planning stage. Therefore, in this study, gap ratio a wind field measuring indicator was developed, and after the ventilation characteristics by layout types and main building uniformity were identified, the scope of gap ratio efficient for ventilation and that of uniformity were clarified, followed by verification through simulation.

• 한국세라믹학회지
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• 제53권1호
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• pp.116-121
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• 2016

The amount of carbon dioxide ($CO_2$) released while producing building materials is substantial and has been targeted as a leading contributor to global climate change. One of the most typical methods of reducing $CO_2$ in building materials is the addition of slag and fly ash, like pozzolan material another method is to reduce $CO_2$ production by developing carbon negative cement. MgO-based cement from the low-temperature calcination of magnesite required less energy and emitted less $CO_2$ than the manufacturing of Portland cements. It is also believed that adding reactive MgO to Portland-pozzolan cements can improve their performance and also increase their capacity to absorb atmospheric $CO_2$. In this study, basic research on magnesia cement using $MgCO_3$ and magnesium silicate ore (serpentine) as the main starting materials, as well as blast furnace slag for the mineral admixture, was carried out for industrial waste material recycling. In order to increase the overall hydration activity, $MgCl_2$ was also added. In the case of the addition of $MgCl_2$as accelerating admixture, there was a promoting effect on the compressive strength. This was found to be due to the production of needle-like dense Mg-Cl hydrates. Mgnesia cement has a high viscosity due to its high specific surface area therefore, when the PC-based dispersing agent was added at a level of more than 1.0%, it had the effect of improving fluidity. In particular, the addition of $MgCl_2$ in magnesia cement using $MgCO_3$and magnesium silicate ore (serpentine) as main starting materials led to a lower expansion ratio and an increase in the freeze-thaw resistance finally, the addition of $MgCl_2$ as accelerating admixture led to good overall durability.

• 한국실내디자인학회논문집
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• 제20권5호
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• pp.170-177
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• 2011

Recently, there has been increasing concern for green growth and environment-friendly construction work is being revitalized; hereupon this study is going to understand the present situation of environment -friendly features of the apartment house through the case study of environment-friendly apartment house in and outside the country, and to suggest the developmental direction of the domestic apartment house. First, this study is to look into respective environment-friendly factors by considering the theoretical background of environment-friendliness and certification of environment-friendly structures, and analyzing the cases of apartment house in and outside the country. This study selected as the survey target the apartment buildings located at 5 places which were completed after 2003 and obtained the domestic 'Green Building Certification Criteria'[hereinafter, GBCC] in metropolitan areas in domestic cases and the survey target to the apartment building at 5 places which were completed after 2003 and obtained the US 'Leadership in Energy and Environment Design' [hereinafter, LEED] in overseas cases. For comparative analysis of each case, this study evaluated each case twice using GBCC and LEED to be more objective in evaluation. As a result, it was found that domestic cases focused on nature-friendly landscaping and the use of the certified products while overseas cases focused on minimizing the environmental impact such as raising the energy reduction ratio and reducing water resources and consumption of resources. Accordingly, there seems to be a need for practical energy-reduction & resources-saving scheme in order for domestic environment-friendly apartment buildings to reach the level of the LEED certification.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.111-114
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• 2010

최근 전 세계적으로 환경문제에 대한 관심이 증가하면서 건축분야에서도 친환경을 위한 노력이 증가하고 있다. 본 논문은 BIM 모델에 근거하여 친환경 현장시공의 위험도 관리에 관한 연구를 하였다. 친환경건축은 지속가능한 발전을 위한 건축으로 3R(Reducing environment pollution, Reducing resource use and Reducing energy source use)표준에 도달해야 한다. BIM은 3D설계, 시공, 유지관리의 효율성 극대화를 위해 건축설계를 2D에서 3D로 전환하고 수량, 공정 및 각종 분석 등의 정보를 통합적으로 활용하는 기술이다. 그리고 4D는 3D기술에 시간을 추가한 것으로써, 3D 모델이나 4D모델에 기반을 두고 있으며, 원가관리, 계획관리, 설계 및 재료관리 등이 BIM 때문에 변화하고 확대하고 있다. 이를 통해 위험관리도를 분석할 수 있다. 본 논문은 먼저 세 분야(환경요소, 자원요소, 에너지요소)에서 친환경 시공의 위험요소를 분석하고 판별하는 방법을 소개한다. 현장에서 일어날 수 있는 위험 확인은 이 공사를 통해서 위험을 판별하고 위험특성도를 찾을 수 있다. 다음으로 친환경위험과 BIM의 관계를 분석한다. 요즘은 BIM이 많이 활용되어서 쉽게 BIM 모델의 데이터베이스를 이끌어 낼 수 있고, 위험을 미리 예방할 수 있으며 옮길 수도 있다. 친환경위험의 세 분야는 분석을 통해서 개별적으로 위험관리를 할 수 있다. 친환경건물은 에너지분야 비율이 비교적 많은데 현장시공의 친환경도 비슷하다. 따라서 위험을 미리 예방하여 에너지를 절약할 수 있다. 소프트웨어를 통해 공간과 에너지성능을 잘 알 수 있고, 사용될 에너지의 전체를 계산할 수 있고, 라이프 사이클 등을 미리 알 수 있다. 그래서 4D모델이나 5D모델을 이용하면서 시공인원이 잘 판별하면 위험을 예방하거나 옮길 수 있다. 특히 시공환경 분야, 시공소음, 수질 오염 등의 문제점을 분석할 수 있다. 친환경공사는 복잡하고, 시간주기도 길어서 자원과 에너지를 많이 소모하기 때문에 친환경위험관리에 적합한 판별이 필요하며, 이를 통해 지속 가능한 발전을 할 수 있다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.925-930
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• 2008

As office automation appliances and communication equipments are adopted in office buildings, internal heat gains increase gradually. When making simulation model, internal heat gains are usually set up with standard values or ignored. Therefore, the impact of the internal heat gains has been ignored or not been focused although it is recognised as significant contributor to heating/cooling load of buildings. This study focused on the impact of internal heat gains on curtain wall buildings. the amount and schedules of heat internal gains profiles not only affect the profiles of heating/cooling loads, but also make impact on reducing the effectiveness of high performance glazing systems. It is important to identify internal heat gains profiles before considering the installation of high performance glazing systems.

• 한국산학기술학회논문지
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• 제14권4호
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• pp.1540-1547
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• 2013

국가 에너지 소비의 25%를 차지하는 건물에너지의 저감과 귀농인구의 증가에 따른 저에너지 친환경 주택모델의 수요 충족을 위해 EnergyPlus를 사용하여 PV 시스템이 적용된 농어촌 주택 표준모델의 건물에너지요구량을 기반으로 경제성 분석을 하였다. 2가지 타입의 PV 시스템이 적용되었고 발전된 전력을 건물의 냉방기기와 전기기기, 그리고 난방기기에 사용하였다. 계산에 사용된 주택의 연간 건물에너지요구량은 난방이 냉방에 비해 7배 크게 나타났다. Case1과 Case2로 나누어 PV 시스템의 경제성분석을 실시한 결과, Case1은 냉난방 및 전기기기에 발전된 전력을 사용하고 판매하는 것이, Case2는 냉방과 전기기기에만 전력을 사용하고 전량 판매하는 것이 경제적으로 유리한 것으로 판단된다. 하지만, 향후 전력 판매가격과 가스가격이 변동되면 결과는 달라질 수 있다. 초기투자비용은 Case1이 약 13년, Case2는 약 11년이 지나면 회수되는 것으로 나타났다. Case2가 초기설치비용이 비싸지만 회수기간이 지나면 Case1보다 약 3배 더 많은 이익을 얻을 수 있어 수명연한인 25년 이상 사용 시 경제성 측면에서 유리할 것으로 판단된다.