• KIEAE Journal
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• v.11 no.1
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• pp.21-28
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• 2011

The objective of this study is to analysis the properties for reclassifying green roofs into three types by cluster analysis after investigating the present condition in thirty green roofs which were created from 2002 to 2004 by Seoul Metropolitan Government. The previous classification was resulted in structure safety diagnosis in the type of green roofs and visible judgment by experts in sites. However, it should have been corrected. Therefore, it needed a reestablished concept and a reclassification in green roofs. The results of this study are as follows : the concept of a rooftop garden and a green roof is different from previous studies. The rooftop gardens named by intensive green roofs are closed to integrated management, whereas the green roofs are closed to low management. The reclassification of green type was also conducted to use the statistic analysis of categorical regression by previous studies, and the factors extracted by the categorical regression were influenced by greening type. The figure of R-square representing explanation in regression analysis is 95.2%. As this result was analyzed, it was proved into rooftop gardens demanded for high activity by people.

• Journal of Korean Association for Spatial Structures
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• v.12 no.3
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• pp.47-54
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• 2012

The roof surface of spatial structures is often damaged or destroyed because of its light weight roof structure and materials. Many of large scale stadiums have roof structure framed with steel truss or stay cable and wrapped or covered with membrane material Teflon, and this membrane material is easily damaged and its loss is quite serious. Through such examples, it was found that the studies on wind proof design of roofs of large space structures were not sufficiently made. This study conducted wind pressure experiment and fluid analysis in order to examine the aerodynamic characteristic of the roof shape of hyperbolic paraboloid spatial structures. Although the biggest minimum peak wind pressure coefficient was shown in the edges of the roof in the wind origin direction, it decreases with the advancement to the longitudinal direction of the roof.

• Journal of architectural history
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• v.27 no.2
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• pp.39-50
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• 2018

This study investigates the types and spread of framed structures of gable roofs meeting at right angle showed in old architecture and documentary paintings of houses, which were well liked in the early Joseon Dynasty. The conclusions of this study were as follows. First, the framed structure of gable roof meeting at right angle can be divided or recognized in 4 types according to their structure's size and purlin's position. Three of those types were noted to be in Seoul. Second, the framed structure of gable roofs meeting at right angle begun from the awareness of their independence from one another. Each space was divided based on their functions. Therefore, it could be extended in various forms, not only in the square plan physique but also in many different forms. And allowed free plan configuration regardless of column layouts or size of structure. Third, 5 purlins and 3 purlins crossing structure were preferred in Han-yang, the early Joseon Dynasty. It is related to the specific construction conditions of urban houses, such as the slope of land, limited land area, and economic power. Fourth, urban housing techniques were diffused throughout the country by officials who lived in Kae-gyeong and Han-yang at the end of Goryeo and early Joseon Dynasty. In other regions, framed structure of gable roof meeting at right angle households decreased, but in some regions of Gyeongsang-province, framed structure of gable roof meeting at right angle has maintained with Staggered purlin.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1997.04a
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• pp.77-87
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• 1997

The earthquake data(M$\geq$4.0) for post-1900 in the Korean Peninsula show temporal variation with active and quiet periods. The pattern is quite similar to northeastern China and Inner Zone of Southwest Japan. Yeongweol earthquake occurred in the seismic gap region of the Korean Peninsula. This is the first medium-size earthquake in inland region of the southern peninsula since 1978. The intensity based on the felt area estimation of about 400 places shows MMI III-Ⅷ in inland region. IIon Cheju Island and Ion Ulreung Island. The isoseismal of MMI Ⅶ shows an elongated circle in the direction of NE-SW and covers some parts of Jungdong-myon, Yeongweol-kun, Sindong-eup and Nam-myun, Jeongseon-kun. There occurred quite strong shaking, numerous cracks on the walls of buildings, falling and movement of slate and tiles on the roofs, falling of tiles from the wall and falling of materials from desks, rook falling from mountain and collapse of gravel lauers on the river side. The least square fitting of the intensity data of the Yeongweol earthquake by a popular intensity attenuation relation yields the following : I=Io＋1.82249 - 0.65295*InR - 0.00707*R

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.2
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• pp.85-94
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• 2018

This study tries to connect the 'four-elements metaphor' of Bachelard with architectural Images of Coop Himmelblau. Two basic terms of 'phenomenology of imagination' and 'material image' are explored firstly to understand the meaning and value of Bachelardienne four-elements in architectural discourse. The material images of air, fire, water, and clay are applied to the analysis of architectural experience of Busan Cinema Center(BCC) which is selected among works of Himmelblau by reason of its integrity of the four-elements' images. After elaborate Bachelardienne description of the images of BCC, the study examines whole Himmelblau's works since 1968 chronologically from the perspective of the four-elements' architectural images which are found in the analysis of BCC. The study of BCC could discover the images of air in two roofs, the images of fire in Double cone, the images of water in outdoor cinema, Dureraum square, flying brides, and the images of clay in Cinemountain and BIFF Hill. The chronological study found that Himmelblau had started their projects with the images of air in 1968 and tried the fire from 1978, and their regular examination of water and clay images had begun in mid 90's. After 2000, they could show a certain harmony of the four elements in their works.

• Structural Monitoring and Maintenance
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• v.9 no.3
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• pp.271-287
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• 2022

This study investigates the bending behavior of a composite concrete slab roof with different methods of externally strengthing using steel plates and carbon fiber reinforced polymer (CFRP) strips. First, the concrete slab model which was reinforced with CFRP strips on the bottom surface of it is validated using experimental data, and then, using numerical modeling, 7 different models of square-shaped composite slab roofs are developed in ABAQUS software using the finite element modeling. Developed models include steel rebar reinforced concrete slab with variable thickness of CFRP and steel plates. Considering the control sample which has no external reinforcement, a set of 8 different reinforcement states has been investigated. Each of these 8 states is examined with 6 different uncertainties in terms of the properties of the materials in the construction of concrete slabs, which make 48 numerical models. In all models loading process is continued until complete failure occurs. The results from numerical investigations showed using the steel plates as an executive method for strengthening, the bending capacity of reinforced concrete slabs is increased in the ultimate bearing capacity of the slab by about 1.69 to 2.48 times. Also using CFRP strips, the increases in ultimate bearing capacity of the slab were about 1.61 to 2.36 times in different models with different material uncertainties.

• Journal of architectural history
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• v.17 no.2
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• pp.67-81
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• 2008

Aldo Rossi explained Roman Forum as a significant urban artifact, because Roman Forum analogically showed not only an image of Roman Empire but also a figure of primitive design for its region. Thus the comparison and analysis between characteristics of Aldo Rossi's architectural works which are based on the theory of 'Analogical city' and the forums, the urban artifacts, was proceeded in this study. Consequently, it was discovered that Aldo Rossi had used his analogical thinking from the forum for his architectural languages such as gable roofs, square windows with depth, columns and so on. His analogical use of organizing spaces, such as courtyard type and pillar corridor type, has also shown that their types came from forum spaces. His analogical aspects of the forum: a space where urban images are analogically formed; were expressed in the 'Theater of Science' with the urban architecture form as the actor and the Theatre as the stage for analogical urban performances. Nevertheless, the expression of primitive design which divides the Roman Forum from other forums was actualized in 'the Theater of the World'. He not only analogically used types from Roman Forum in architectural design but also used boat in Water space, which decided the lifestyle and culture of Venice even before the civilization, to express the primitive design of Venice. Consequently, Aldo Rossi, by aiming the severance from the tradition, provided the possibility of explaining the newest modem type within the historical meaning by forming type which finds its continuance in history through 'the Theater of the World' and through analogical thinking along with the level of modern culture, to our urban architectural atmosphere that has lost its historical meanings.

• KIEAE Journal
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• v.15 no.4
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• pp.85-90
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• 2015

Purpose: In design and planning Building Integrated Photovoltaic(BIPV) system can reduce cost by replacing building facade as construction material such as roofs, outer walls and windows as well as generating electricity. BIPV system should be applied at the early stage of architectural design. However, it is hard to decide whether using BIPV system or not for architects and builders who are not professional at BIPV system because performance of system is considerably influenced by types of module, installation position, installation methods and so on. It is also hard for experts because commercialized analytical program of photovoltaic systems is too complicated to use and domestic meteorological data is limited to partial areas. Therefore, we need evaluation program of BIPV system which can easily but accurately interpret generating performance and evaluate validity of BIPV system at the early stage of architectural design even for inexpert. Method: In this study, we collected meteorological data of domestic major region and analyzed generation characteristic of BIPV system by using PVsyst(commercialized software) in accordance with regions, types of solar module, place and methods of installation and so on. Based on this data, we developed performance evaluation program of BIPV system named BIPV-Pro, through multiple regression analysis and evaluated its validity. Result: When comparing predictive value of annual average PR and annual electricity production of BIPV-Pro an that of PVsyst, each of root mean square error was 0.01897 and 123.9.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.663-670
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• 2020

In the present study, we assessed the accuracy of aerial triangulation using a UAV (Unmanned Aerial Vehicle) capable of network RTK (Real-Time Kinematic) survey in a disaster situation that may occur in a semi-urban area mixed with buildings. For a reliable survey of check points, they were installed on the roofs of buildings, and static GNSS (Global Navigation Satellite System) survey was conducted for more than four hours. For objective accuracy assessment, coded aerial targets were installed on the check points to be automatically recognized by software. At the instance of image acquisition, the 3D coordinates of the UAV camera were measured using VRS (Virtual Reference Station) method, as a kind of network RTK survey, and the 3-axial angles were achieved using IMU (Inertial Measurement Unit) and gimbal rotation measurement. As a result of estimation and update of the interior and exterior orientation parameters using Agisoft Metashape, the 3D RMSE (Root Mean Square Error) of aerial triangulation ranged from 0.153 m to 0.102 m according to the combination of the image overlap and the angle of the image acquisition. To get higher aerial triangulation accuracy, it was proved to be effective to incorporate oblique images, though it is common to increase the overlap of vertical images. Therefore, to conduct a UAV mapping in an urgent disaster site, it is necessary to acquire oblique images together rather than improving image overlap.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.357-364
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• 2014

This study aimed to determine effects of the use of water-retention additive, hydrophilic polymer, for extensive green roofs on growth of Juniperus chinensis var. sargentii and Euonymus fortunei 'Emerald and Gold' for woody plants, and Carex kobomugi and Carex pumila for herbaceous plants. Five different contents of hydrophilic polymer including 0% (Control), 1.0%, 2.5%, 5.0%, and 10% (polymer: medium (w/w), dry weight basis) were added to each of the container filed with a 100 kg of growth medium. Ten of plants were transplanted in each of square container ($1m(L){\times}1m(W){\times}0.3m$ (H)) built on the roof platforms in randomized complete block design in the $20^{th}$ of May, 2013. In results, excessively high volumetric soil water content, about 97-98%, was found in the substrate under elevated hydrophilic polymer concentration of at least 2.5%, during the entire growing period. The moisture content of the substrate containing 1.0% of hydrophilic polymer was higher about 20% in the range between 70% and 80%, compared tho that of Control substrate in the range between 50% and 60%, for 27 days after transplanting prior to abundant rainfall, indicating that the application of hydrophilic polymer to the extensive green roof substrate is effective to eliminate drought condition by retaining water in the substrate. Euonymus fortunei 'Emerald and Gold' and Carex kobomugi resulting in higher plant growth with 2.5% than those of the other treatment plants. Juniperus chinensis var. sargentii was observed the highest growth under 1.0% hydrophilic polymer treatement, and Carex pumila was founded the best growth with Control respectively. Plants that grown in both the 1.0% and 2.5% hydrophilic polymer survived all, while the plants that grown in the 5.0% and 10% hydrophilic polymer died after 3 months. These results suggest that advantage of the addition of hydrophilic polymer may be greater in drought-tolerant plants, but the mixture proportion of hydrophilic polymer should be determined according to the different features of the plant species being grown.