• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.248-250
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• 2003

An automatic approach and strategy for extracting building information from aerial images using combined image analysis and interpretation techniques is described in this paper. A dense DSM is obtained by stereo image matching. Multi-band classification, DSM, texture segmentation and Normalised Difference Vegetation Index (NDVI) are used to reveal building interest areas. Then, based on the derived approximate building areas, a shape modelling algorithm based on the level set formulation of curve and surface motion has been used to precisely delineate the building boundaries. Data fusion, based on the Dempster-Shafer technique, is used to interpret simultaneously knowledge from several data sources of the same region, to find the intersection of propositions on extracted information derived from several datasets, together with their associated probabilities. A number of test areas, which include buildings with different sizes, shape and roof colour have been investigated. The tests are encouraging and demonstrate that the system is effective for building extraction, and the determination of more accurate elevations of the terrain surface.

• 한국환경복원기술학회지
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• 제11권6호
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• pp.143-152
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• 2008

A comparative analysis of rooftop greening in Korea and Japan was carried out to understand current status of rooftop greening creation and technology and to give directions to frame a policy or plan on rooftop greening in Korea. Besides literature studies, questionnaire survey to Korean and Japanese experts on rooftop greening were done. As results, the annual creation areas, the types and the scales of rooftop greening in Seoul and Tokyo until 2007 were analysed and the satisfaction on the creation areas and technologies, the preference types, the present levels of and the most important parts among policies (support systems), technologies (creation methods), materials, maintenances and user programs for the development or expansion of rooftop greening in Korea and Japan were compared. The creation areas of rooftop greening in Seoul until 2007 was around 15% in Tokyo but the increasing rate of those in Seoul was faster than in Tokyo. Korean needs for the improvement on the rooftop greening systems and technologies were higher than Japanese, but both desired the expansion of rooftop greening areas in both countries. Korean preferred semi-intensive rooftop greening system but Japanese preferred intensive system. Korean and Japanese rooftop greening experts preferred policies (support systems) and technologies (creation methods) for the most important part for the development or expansion of rooftop greening in both countries.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.524-528
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• 2009

The objectives of this study were to install RCR systems at a typical single family house and a school in Alabama, and evaluate the feasibility and efficiency of using the RCR systems for water harvesting in Alabama. The RCR systemswere equipped with a control system and a CR10X data logger to monitor the system operation and to collect data on precipitation, temperature, overflow, water depth in the storage tank and daily uses of toilet flushing. Daily average water use of the home for toilet flushing was 95 liter and 2100 liter was used at the school during the school days. Rainwater harvesting efficiency was 83.3 and 89 percent and RCR use efficiency was 18 and 98 percent from the home and the school, respectively. A computer program was developed to estimate potential effectiveness of RCR systems. From the analysis result with 10 years rainfall data, a total of 67,000 liters of rainwater could be harvested for domestic uses from a typical single family house which supplies 190 liters per day.

• 한국지진공학회논문집
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• 제21권6호
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• pp.311-322
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• 2017

In this study, the seismic performance of concrete-steel composite moment frame structures equipped with seismic retrofitting systems such as seismic reinforcement, base isolators, and bracing members, which are typical earthquake damage mitigation systems, is evaluated through nonlinear dynamic analyses. A total of five frame models were designed and each frame model was developed for numerical analyses. A total of 80 ground acceleration data were used to perform the nonlinear dynamic analysis to measure ground shear force and roof displacement, and to evaluate the behavioral performance of each frame model by measuring inter-story drift ratios. The analysis results indicate that the retrofitting device of the base isolator make a significant contribution to generating relatively larger absolute displacement than other devices due to flexibility provided to interface between ground and column base. However, the occurrence of the inter-story drift ratio, which is a relative displacement that can detect the damage of the structure, is relatively small compared with other models. On the other hand, the seismic reinforced frame model enhanced with the steel plate at the lower part of the column was found to be the least efficient.

• Wind and Structures
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• 제4권3호
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• pp.213-226
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• 2001

Wind uplift rating of roofing systems is based on standardised test methods. Roof specimens are placed in an apparatus with specified table size (length and width) then subjected to the required wind load cycle. Currently, there is no consensus on the table size to be used by these testing protocols in spite of the fact that a table size plays a significant role in evaluating the performance. This paper presents a study with the objective to investigate the impact of table size on the performance of roofing systems. To achieve this purpose, extensive numerical experiments using the finite element method have been conducted to investigate the performance of roofing systems subjected to wind uplift pressures. Numerical results were compared with results obtained from experimental work to benchmark the numerical modeling. Required table size and curves for the determinations of appropriate correction factors are suggested. This has been completed for various test configurations with thermoplastic waterproofing membranes. Development of correction factors for assemblies with thermoset and modified bituminous membranes are in progress. Generalization of the correction factors and its usage for wind uplift rating of roofs will be the focus of a future paper.

• 한국공간구조학회논문집
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• 제20권4호
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• pp.141-147
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• 2020

Single-layered grid space steel roof structure is an architectural system in which the structural ability of the nodal connection system greatly influences the stability of the entire structure. Many bolt connection systems have been suggested to enhance for better construct ability, but the structural behavior and maximum resistance of the connection system according to the size of bolt clearance play were difficult to identify. In particular, the identification of bending stiffness of the connection system is very important due to the characteristics of shell structures in which membrane stresses based on bending force effect significantly. To identify effective structural behavior and maximum bearing force, four representative nodal connection systems were selected and nonlinear numerical analysis were performed. The numerical analysis considering the size of the bolt clearance were performed to investigate structural behavior and maximum values of the bending force. In addition, the type of effective nodal connection system were evaluated. As a result, the connection system, which has two shear plane, represented high bending stiffness.

• 한국지진공학회논문집
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• 제12권2호
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• pp.69-80
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• 2008

본 연구에서는 중고층 건물과 같이 고차모드의 영향이 커지는 구조물의 지진에 대한 성능점을 간략하고 정확하게 구할 수 있는 개선된 능력스펙트럼법을 제안한다. 능력스펙트럼법은 주어진 지진의 응답스펙트럼과 다자유도 구조물을 변환한 등가 단자유도 시스템을 이용하여 지진으로 인하여 발생하는 지붕층의 최대 비탄성변위를 간략하게 구하는 방법이다. 제안된 방법에서는 구조물의 탄성 및 비탄성 동적해석을 수행하지 않고, 기존의 능력스펙트럼법에서 요구되는 정적푸쉬오버해석과 탄성변위를 이용하여 비탄성변위를 예측하는데, 기존 연구에서 개발한 $C_R$을 이용한다. 본 연구는 제안한 방법의 정확도를 평가하기 위해 LA 지역의 3, 9, 20층 철골모멘트저항골조를 선택한다. 이 건물들의 지진에 대한 각 층별 최대 층간변위비를 개발한 CSM으로 구하고, 이를 비선형 응답이력해석(NL-RHA)으로 구한 결과와 비교하였다. 사용한 지진은 재현주기 475년과 2475년의 위험수준에 대한 각각 20개의 지진집단들이다. 또한 본 연구에서는 ATC-40에 제시된 CSM 방법과 N2 방법으로 구한 각 건물의 최대 층간변위비도 비교한다. 개발된 CSM은 기존에 개발된 방법에 비하여 보다 정확한 최대 층간변위비를 예측하는 것으로 나타났다.

• 한국산학기술학회논문지
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• 제16권1호
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• pp.1-7
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• 2015

일반적으로 유리온실의 거터는 빗물이나 결로를 온실 밖으로 배출시키는 역할을 하는 구조물이다. 본 논문에서는 기존 거터를 개량하여 질량을 줄이고 온실의 온도차이로 발생하는 결로를 많이 담을 수 있는 새로운 거터를 설계한다. 개발할 거터는 CATIA로 설계한 후 ANSYS 구조해석과 ADAMS/Durability를 이용하여 Hot Spot해석을 수행한 결과를 바탕으로 설계하였으며, 거터의 성능을 개선하기 위해 거터의 형상, 결로의 배수, 강도 등을 고려하였다. 그리고, 개발할 거터는 설치 방법이 쉬운 결로받이 일체형 거터이며, 기존 거터보다 질량이 약 16.9% 감소하였으며 내구성도 약 10% 상향되었다.

• 생물환경조절학회지
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• 제23권3호
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• pp.181-191
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• 2014

Modern commercial greenhouse requires the use of advanced climate control system to improve crop production and to reduce energy consumption. As an alternative to classical sensor-based control method, this paper introduces a model-based control method that consists of two models: the predictive model and the evaluation model. As a first step, this paper presents straightforward models to predict the effect of natural ventilation in a greenhouse according to meteorological factors, such as outdoor air temperature, soil temperature, solar radiation and mean wind speed, and structural factor, opening rate of roof ventilators. A multiple regression analysis was conducted to develop the predictive models on the basis of data obtained by computational fluid dynamics (CFD) simulations. The output of the models are air temperature drops due to ventilation at 9 sub-volumes in the greenhouse and individual volumetric ventilation rate through 6 roof ventilators, and showed a good agreement with the CFD-computed results. The resulting predictive models have an advantage of ensuring quick and reasonable predictions and thereby can be used as a part of a real-time model-based control system for a naturally ventilated greenhouse to predict the implications of alternative control operation.

• 한국공간구조학회논문집
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• 제10권1호
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• pp.67-74
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• 2010

국내에 설치될 강구조 스타디움에 향후 신재생에너지 중 하나인 태양광 발전을 위한 PV 시스템을 적용하는 것에 따른 강재 어레이에 관한 기초 연구로 해외의 사례를 토대로 구성되었다. 연구를 진행하기 위하여 1990년대 이후 PV 시스템이 적용된 강구조 스타디움 20건을 사례 분석 대상으로 선정하였다. 선정된 20건의 강구조 스타디움을 PV 모듈을 고정하기 위하여 설치된 레일 시스템에 따라 분류해 보았다. 그 결과 격자고정방식 중 선형모듈고정방식과 지붕 통합형이 전체의 28%에 해당되는 것으로 조사되었으며 그 뒤로 레일 고정형 17%, 세로 고정방식 중 모듈그룹 고정 11% 순으로 조사되었다. 또한 스타디움 내부에는 주로 격자 고정방식 중 선형모듈 고정방식과 지붕통합형이 적용되고 있었으며 스타디움 외부나 그 외 부분에서는 앵글 브라킷으로 PV 모듈이 고정되고 있는 것으로 조사되었다.