• Journal of the Korean Solar Energy Society
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• v.29 no.4
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• pp.28-33
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• 2009

In 2008, the global photovoltaic(PV) market reached 5.6GW and the cumulative PV power installed totalled almost 15GW compared to 9GW in 2007. Due to a favourable feed-in-tariff, Korea emerged in 2008 as the 4th largest PV market worldwide. PV power installation rose 495.5 percent to 268MW in 2008 compare to 45MW in 2007. Building integrated photovoltaic(BIPV) has the potential to become a major source of renewable energy in the urban environment. BIPV has significant influenced on the reflection by rear materials such as white back sheet and the heat transfer through the building envelope because of the change of the thermal resistance by adding or replacing the building elements. In this study, to use as suitable building materials into environmentally friendly house like green home, characteristic analysis of BIPV module according to rear materials achieved. Electrical output of PV module with white back sheet is high about 10% compared to other pv module because of 83% reflectivity of white back sheet compared to 8.4% reflectivity of other PV modules with different rear materials(black back sheet and glass). In the result of outdoor experiment during a year, electrical output of four different PV module is decreased about 3.72%.

• Journal of the Korean Wood Science and Technology
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• v.35 no.1
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• pp.64-72
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• 2007

The biodeterioration behaviors of square post to support the wooden printing blocks Shelves in the Janggeongpanjeon were investigated according to the positions and parts of square post, and environmental conditions. It was found that a high differences of deterioration in the progressing levels of wood decay, according to the positions and parts of square post, and environmental conditions. The decay levels were very high and still progressing in the contacted areas with stone foundation which are about up to 50 cm above it. In the decay type, white rot fungi was mainly affected in the inside of building which mainly made of softwood. The decay in the square posts to support the wooden printing block shelves inside of building was worse in the rear side, compared to front side. The insects was not found in most of square posts excluding the post which was neighboring at the infected round column by insect.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.3
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• pp.197-204
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• 2024

In this paper, the structural performance of Suwon Hwaryeongjeon Unhangak, a representative traditional timber structure in the late Joseon Dynasty, was evaluated. Based on the structure composition of Unhangak, an analysis model was elaborately constructed with Midas Gen, a 3-dimensional structural analysis software. The safety and serviceability of major structural members were evaluated by static analysis, and the dynamic behavior characteristics were evaluated by eigenvalue analysis. Most of the members satisfied the safety and serviceability standards with a margin; however, the bending stress ratio in the oemogdori exceeds the standard by 20.7%, so it is considered that long-term monitoring is needed for this member. The natural period of Unhangak is 1.079 seconds, which is slightly longer than traditional timber buildings of similar scale. In particular, it is analyzed that torsional movement occurred in the secondary mode due to the influence of the rear masonry firewall.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.396-396
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• 2011

유연기판(Flexible) CIGS 박막태양전지는 금속 및 폴리머 기판을 이용하고 roll-to-roll 공정에 적합하기 때문에 유리기판을 이용한 태양전지에 비해 가볍고 공정단가를 절감할 수 있다. 그러나 기존의 soda-lime 유리 기판에 비해 금속 및 폴리머 기판을 사용시 Na 공급의 부재로 CIGS 박막 태양전지는 Voc, FF의 감소로 효율이 감소한다. 본 연구에서는 기존 유리기판과 유사한 Na의 공급을 위해 soda lime 유리 박막(SLGTF)을 Mo 후면전극 증착 전에 도입하였으며, CIGS 박막 및 태양전지를 제조함으로써 SLGTF의 영향을 분석하였다. SLGTF는 rf magnetron 스퍼터링법으로 두께를 조절하여 철강기판과 Mo 사이에 증착하였다. 본 연구에서는 SLGTF의 두께에 따른 CIGS 박막의 미세구조 및 Na 함량의 변화를 기존의 유리기판 및 SLGTF이 없는 철강기판과 비교하여 분석하고자 하였다. CIGS 박막은 3-stage 진공증발법으로 증착하였으며, CIGS 박막의 우선배향성(texture) 변화를 관찰하기 위해 XRD (X-ray Diffraction)를 이용하였고 Na 양을 확인하기 위해 SIMS(Secondary Ion Mass Spectroscopy)를 사용하였다. SLGTF의 도입 및 두께의 변화에 따라 CIGS 박막의 우선배향성(texture) 및 Na의 양에 큰 변화가 있었으며, 이러한 변화가 CIGS 태양전지 셀 효율에 미치는 영향을 분석하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.3
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• pp.201-209
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• 2002

Crib wall system is one of segmental crib type wall. Crib walls are constructed from separate members with no bonds between them other than frictional. The wall units are divide into two main types termed headers and stretchers. The headers run from the front to the back of the wall, perpendicular to the wall face. The cells are created by forming a grid by stacking individual wall components known as headers and stretchers. The body of wall consists of a system of open cell which are filled with a granular material. The design of crib retaining wall is usually based on conventional design methods derived from Rankine and Coulomb theory so that is able to resist the thrust of soil behind it, because it may be assumed that the wall acts as a rigid body. However, deformation characteristics of crib walls cannot be assumed as monolithic. They consist of individual members which have been stacked to creat a three dimensional grid. Therefore, the segmental grid allows relative movement between the individual member within the wall. The three dimensional flexible grid leads to stress distribution by interaction behavior between soil and crib wall. Therefore, in this study, in order to analysis the trends of deflection of crib wall system, new numerical models based on the results of Brandl's full scale test are introduced for design concept.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.1
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• pp.10-19
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• 2021

This study investigated the actual state and transformation of the major garden ornaments in Changdeokgung Palace(昌德宮) in the modern and contemporary period, focusing on Nakseonjae(樂善齋), Juhamnu(宙合樓), Jondeokjeong(尊德亭), and Daebodanji (大報壇址). This study can be used as useful data for establishing the restoration and maintenance plan of the garden ornaments in Changdeokgung Palace, and the main results of the study can be summarized as follows. First, according to a photo taken by the Czech Vráz, in 1901, a total of six garden ornaments, including a stone pond and odd-shaped stones, were located in the backyard of Nakseonjae. Since liberation, arbitrary relocation of garden ornaments has frequently occurred, and in the process, two odd-shaped stones, originally located on the first floor of the terraced flower bed, have been transferred to the backyard of Gyeonghungak(景薰閣). Second, unlike the late Joseon Dynasty when 「Donggwoldo(東闕圖)」 was produced, odd-shaped stones were arranged symmetrically in the backyard of Juhamnu in the early 1900s. It was a traditional style garden ornament with similar appearance, size, and design. However, all the odd-shaped stones in the backyard of Juhaumnu were relocated to other places in the 1970s and 1980s. One is located at the rear of Aeryeonjeong(愛蓮亭) through the entrance of Bingcheon(氷泉) and the vicinity of Geumcheongyo(錦川橋), and the other remains in front of the Yeongyeongdang Jangnakmun(演慶堂 長樂門). Third, among the garden ornaments located in the area of Jondeokjeong in the past, one odd-shaped stone is now relocated around the stone bridge near the pavilion and the Yeonghwadang(暎花堂) with its components separated. The bondstone near Yeonghwadang was relocated in 1990 for the purpose of installing an imitation of Angbuilgu(仰釜日晷). Another odd-shaped stone has been relocated to the front door of the Secret Garden(後苑), and now it is difficult to grasp the location. Fourth, the two bondstones remaining in the Daebodanji were actually building materials that were used as the foundation stone for the entrance pillars of the Yi Royal Office Building(李王職廳舍) during the Japanese colonial period. After liberation, the Yi Royal Office Building was reorganized into Imperial Estate Administration Office(皇室財産事務總局), and when the office building was burned down in 1960, the stone statues and foundation stones placed on the stylobate were relocated to the Daebodanji. The bondstone at Daebodanji is a representative example of construction materiasl being mistaken for gaeden ornaments.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.5
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• pp.339-349
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• 2020

Double-leaf blast-resistant doors consisting of steel box and slab are application-specific structures installed at the entrances of protective facilities. In these structural systems, certain spacing is provided between the door and wall. However, variation in the boundary condition and structural behavior due to this spacing are not properly considered in the explosion analysis and design. In this study, the structural response and failure behavior based on two variables such as the spacing and blast pressure were analyzed using the finite element method. The results revealed that the two variables affected the overall structural behavior such as the maximum and permanent deflections. The degree of contact due to collision between the door and wall and the impact force applied to the door varied according to the spacing. Hence, the shear-failure behavior of the concrete slab was affected by this impact force. Doors with spacing of less than 10 mm were vulnerable to shear failure, and the case of approximately 15-mm spacing was more reasonable for increasing the flexural performance. For further study, tests and numerical research on the structural behavior are needed by considering other variables such as specifications of the structural members and details of the slab shear design.