• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.942-945
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• 2010

분산형 전원은 에너지 실수요자 근처 혹은 건물 내부에 소형 발전설비(태양광, 풍력 발전을 포함하는 신재생에너지 발전)를 설치해 에너지 손실과 송 배전 설비를 줄이려는 노력에서 출발했다. 최근 세계적으로 기후 환경 변화에 대처하기 위해 다양한 신재생에너지를 활용하기 위한 댁내 분산형 전원 환경 시대를 예고하고 있다. 특히 태양광, 풍력 발전은 댁내에 설치하기 용이하고 가장 경제성이 뛰어나 많은 기업들이 적극적으로 사업에 진출하고 있다. 하지만 풍력 발전의 경우 바람의 세기에 따라 발전량의 변화가 심하고, 태양광은 일사량 및 일조량의 영향을 많이 받기 때문에 기후 상황에 따라 출력이 불안정하다는 단점이 있기 때문에 균일한 전력품질을 제공하기 위해 해결해야 할 기술적인 과제를 가지고 있다. 본 논문에서는 댁내에서 운용이 용이한 풍력 에너지, 태양광 에너지 및 기존 전력으로 구성되는 분산형 전원시스템에서 기후변화에 민감한 신재생에너지 발전량의 예측 방법에 대해 제안한다. 이를 바탕으로 효율적인 분산전력 관리를 가능하게 하며, 궁극적으로 제로에너지 홈을 구현하기 위한 기본 요소 기술을 제공하는 것이 본 논문의 목표이다.

• 한국구조물진단유지관리공학회 논문집
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• 제19권5호
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• pp.45-55
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• 2015

현재 전 세계적으로 자연적, 인위적 요인으로 인하여 이상기후가 나타나고 있다. 이상기후의 대표적인 것으로 슈퍼태풍, 극한폭설, 폭염과 같은 극한 기후현상이 초래된다. 1970년대 산업화 시대 이후 급격하게 지구의 온도가 상승하는 것을 알 수 있으며, 이로 인하여 발생하는 가장 큰 문제점은 지구 온난화이다. 지구 온난화에 영향을 미치는 온실가스의 종류로는 이산화탄소, 과불화탄소, 아산화질소, 메탄과 같은 다양한 종류의 화학성분이 존재하며 특히 이산화탄소가 약 90%의 비중을 차지하는 것을 알 수 있다. 콘크리트의 경우 건설재료로써 탁월한 내구성능을 지니고 있으며, 사회기반시설물 건설 재료로 70%이상 사용되고 있다. 그러나 콘크리트는 타설직후 물리 화학적으로 다양한 환경조건으로부터 성능저하 현상이 발생하기도 한다. 특히 대기중의 이산화탄소는 콘크리트 알칼리도 저하에 따른 철근을 부식시키고 내구성 저하를 초래하게 된다. 따라서 본 연구에서는 풍속, 일조시간에 관하여 양생 한 후 콘크리트의 탄산화 실험을 접목시켜 탄산화 깊이와 탄산화 속도계수를 측정하고 이를 바탕으로 만족도 확률 곡선을 통하여 성능중심평가(Performance Based Evaluation(PBE))를 수행 할 것이다.

• Smart Structures and Systems
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• 제20권3호
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• pp.385-396
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• 2017

The recent advancements in sensing technologies allow us to record measurements from target structures at multiple locations and with relatively high spatial resolution. Such measurements can be used to develop data-driven methodologies for condition assessment, control, and health monitoring of target structures. One of the state-of-the-art technologies, Fiber Optic Strain Sensors (FOSS), is developed at NASA Armstrong Flight Research Center, and is based on Fiber Bragg Grating (FBG) sensors. These strain sensors are accurate, lightweight, and can provide almost continuous strain-field measurements along the length of the fiber. The strain measurements can then be used for real-time shape-sensing and operational load-estimation of complex structural systems. While several works have demonstrated the successful implementation of FOSS on large-scale real-life aerospace structures (i.e., airplane wings), there is paucity of studies in the literature that have investigated the potential of extending the application of FOSS into civil structures (e.g., tall buildings, bridges, etc.). This work assesses the feasibility of using FOSS to predict operational loads (e.g., wind loads) on chain-like structures. A thorough investigation is performed using analytical, computational, and experimental models of a 4-story steel building test specimen, developed at the University of Southern California. This study provides guidelines on the implementation of the FOSS technology on building-like structures, addresses the associated technical challenges, and suggests potential modifications to a load-estimation algorithm, to achieve a robust methodology for predicting operational loads using strain-field measurements.

• 국제초고층학회논문집
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• 제4권1호
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• pp.9-25
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• 2015

Field measurements of various structures have been conducted for many purposes. Measurement data obtained by field measurement is very useful to determine vibration characteristics including dynamic characteristics such as the damping ratio, natural frequency, and mode shape of a structure. In addition, results of field measurements and modal identification can be used for modal updating of FEM analysis, for checking the efficiency of damping devices and so on. This paper shows some examples of field measurements and modal identification for structural health monitoring. As the first example, changes of dynamic characteristics of a 15-story office building in four construction stages from the foundation stage to completion are described. The dynamic characteristics of each construction stage were modeled as accurately as possible by FEM, and the stiffness of the main structural frame was evaluated and the FEM results were compared with measurements performed on non-load-bearing elements. Simple FEM modal updating was also applied. As the next example, full-scale measurements were also carried out on a high-rise chimney, and the efficiency of the tuned mass damper was investigated by using two kinds of modal identification techniques. Good correspondence was shown with vibration characteristics obtained by the 2DOF-RD technique and the Frequency Domain Decomposition method. As the last example, the wind-induced response using RTK-GPS and the feasibility of hybrid use of FEM analysis and RTK-GPS for confirming the integrity of structures during strong typhoons were shown. The member stresses obtained by hybrid use of FEM analysis and RTK-GPS were close to the member stresses measured by strain gauges.

• 한국실내디자인학회논문집
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• 제11호
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• pp.45-56
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• 1997

In the process of modermization the problem of environment destruction has become a worldwide issue. And now this problem is a concern for all branches of science, including that of architectural desigv. This thesis tries to find the meaning of ecological architectural space, one that encreases the organic relationship, and communication, between architectrual space and urban environmental space, between human beings and architecture, and between human beings and their environment. As an example, we will take a look at the architectural space-design of Frei Otto, who offers diverse creative ecological architectural forms. His concept of architecture has the critical character when compared with the traditionan conventional concept of architecture. The ecological characteristics of his architectural spacedesign can be summarized as follows: The first characteristic is his ample use of natural objects in the architectural structure. An ample use of living things like trees and plants as well as of inanimate thing like water, wind as architectural elements enhances the functional efficiency of architecture. The second characteristic is its ecological architectural system, which saves energy faciliates ventilation by changing the position and direction of the building, by systematically applying the materials, and by efficiently arranging the inner space. The third characteristic is the dematerialization of architecture and the use of materials that are economical and appropriate for the circulation system of nature. The use of natural elements and recycling natural objects, makes it possible to reuse materials of the destroyed building. In short, the ecological architecture of Frei Otto, which shows the relation between human beings and architecture, presents diverse possibilities of the archtectural space as a complex natural system, which is more than a simple combination of separatge elements.

• 한국농촌건축학회논문집
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• 제20권1호
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• pp.69-76
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• 2018

This study is to research technical measures for improving energy efficiency in the conservation and reuse of historic buildings focused on the recent research trends and case studies of the west. These measures are broadly classified into three types, the passive measures for saving energy and increasing comfort, the most cost-effective energy saving strategies, and the renewable energy sources. Firstly, the passive measures are divided into the elements and systems. The passive elements are awnings and overhanging eaves, porches, shutters, storm windows and doors, and shade trees. There are also the natural ventilation systems such as the historic transoms, roofs and attics to improve airflow and cross ventilation to either distribute, or exhaust heat. Secondly, the most cost-effective energy efficiency strategies are the interior insulation, airtightness and moisture protection, and the thermal quality improvement of windows. The energy efficiency solutions of modern buildings are the capillary-active interior insulation, the airtightness and moisture protection of interior walls and openings, and the integration of the original historic window into the triple glazing. Beyond the three actions, the additional strategies are the heat recovery ventilation, and the illumination system. Thirdly, there are photovoltaic(PV) and solar thermal energy, wind energy, hydropower, biomass, and geothermal energy in the renewable energy sources. These energy systems work effectively but it is vital to consider its visual effect on the external appearance of the building.

• 대기
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• 제17권4호
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• pp.381-391
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• 2007

The characteristics of flow around a single obstacle with fixed height and varied length and width are numerically investigated using a computational fluid dynamics (CFD) model. As the obstacle length increases, flow distortion near the upwind side of the obstacle increases and the size of the recirculation zone behind the obstacle also increases. As the obstacle width increases, the size of the recirculation zone decreases, despite almost invariable flow distortion near the upwind side of the obstacle. Flow passing through an obstacle is separated, one part going around the obstacle and the other crossing over the obstacle. The size of the recirculation zone is determined by the distance between the obstacle and the point (reattachment point) at which both the flows converge. When the obstacle width is relatively large, flows are reattached at the obstacle surface and their recoveries occur. Resultant shortening of the paths of flows crossing over and going around decreases the size of the recirculation zone. To support this, the extent of flow distortion defined based on the change in wind direction is analyzed. The result shows that flow distortion is largest near the ground surface and decreases with height. An increase in obstacle length increases the frontal area fraction of flow distortion around the obstacle. In the cases of increasing the width, the frontal area fraction near the upwind side of the obstacle does not change much, but near the downwind side, it becomes larger as the width increases. The frontal area fraction is in a better correlation with the size of the recirculation zone than the building aspect ratios, suggesting that the frontal area fraction is a good indicator for explaining the variation in the size of the recirculation zone with the building aspect ratios.

• 보존과학회지
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• 제34권4호
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• pp.283-293
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• 2018

This study involved a comparative analysis of the correlation between meteorological elements and the concentration of airborne fungi(CFU) in relation to biological damage to two temples on piedmonts, which is a cultural heritage building. The work compared Beopjusa temple in Boeun(Chungcheongbuk-do Province) and Seonamsa temple in Suncheon(Jeollanam-do Province). Twelve meteorological elements and the CFU were measured and the Pearson correlation analysis was used to determine the degree of the relationship between them. The results showed that Beopjusa temple had high wind speed, high total horizontal radiation, high evaporation, and large number of days with precipitation. Seonamsa temple had high air temperature, high relative humidity, high dew point temperature, high sea level pressure, high precipitation, and high CFU. The CFU at Beopjusa temple did not have a linear correlation with meteorological elements, but at Seonamsa temple it was highly positive correlated with the number of days with precipitation, relative humidity, and precipitation, and was highly negative correlated with total horizontal radiation. In addition, Beopju and Seonamsa temple had a common linear relationship between factors not affected by the topographical conditions, and had a individual linear correlation between factors affected by the topographical conditions.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.190-195
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• 2009

Since the industrial revolution, the global environmental problems such as greenhouse gas accumulation and the average temperature increase have caused people's attention. 'Low Carbon, Green Growth' was presented to cope with these global concerns, as one of main policies of 2008 in Korea. The paradigm of a green urban development is started to concern the whole city's energy problems owing to realize 'Low Carbon, Green Growth' in the urban side. The government established a nation's basic energy plan for 20 years, and some local cities made efforts to develop new renewable energy such as the solar, wind and water energy which are suitable to each city's character. As a part of these efforts, the concept of U-Eco city is newly appeared to reflect upon ubiquitous technique, urban ecology and the next generation energy system. However, urban plan is difficult to adopt this next generation energy system with existing laws, regulations and technical systems. The new executive and systematic system is needed to realize the U-Eco city U-Eco for the management of an efficient city. In this study, the authors investigate the concept of the next generation energy system and U-Eco city to realize the energy-efficient city plan and analyze problems to occur during the application of them in an existing city plan. Then, the authors show the remedies to deal with occurred problems.

• 한국전산구조공학회논문집
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• 제30권3호
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• pp.199-206
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• 2017

본 논문에서는 약진 지역에서 적용되는 스태거드트러스 골조시스템의 수평하중에 대한 구조특성을 분석하였다. 스태거드트러스 시스템에 적용되는 프랫, 하우, 와렌, K형, 비렌딜의 대표적인 트러스 형태를 기준으로 10층과 20층의 예제 건물에 대한 해석과 설계를 수행하여 트러스 형태에 따른 시스템의 경제성과 효율성을 비교.분석하였다. 설계에서 기둥 및 트러스 부재는 같은 부재를 몇 개 층씩 그루핑하여 사용하였으며 부재의 효율성은 그루핑된 부재의 평균 내력비를 기준으로 판단하였으며 시스템의 경제성은 전체 골조물량을 기준으로 판단하였다. 분석 결과 효율성과 경제성 측면에서 10층의 예제에서는 프랫트러스를 사용한 시스템이 우수한 것으로 나타났으며 20층의 예제에서는 와렌트러스를 사용한 방식이 우수한 것으로 나타났다.