• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.276-279
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• 2008

In order to measure sound transmission loss (STL) of a shipboard window of small size, a special partition is built into the test opening between two reverberation rooms and the specimen is placed in that partition. For high sound insulation, the filler wall often has multi-layered structure such as double-brick wall or buckhead structure with thick steel plate, absorptive material, and sandwich panels. This paper discusses the installation method of a multi-layered filler wall that consist of gypsum boards, lead plates, and glass wool. The experimental results of various wall structures are introduced. The comparison between the results show that the sound bridge effect plays a significant role in lowering the maximum STL of the filler wall. It is also found that the higher the sound insulation performance of the filler wall is, the more important the franking transmission through other side wall of the test facility is.

• Advances in concrete construction
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• v.8 no.2
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• pp.77-90
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• 2019

This paper aims to investigate vibration frequency decrease (vibration period elongation) of reinforced concrete (RC) structure with unreinforced infill wall and reinforced infill wall exposed to progressively increased artificial earthquake load on shaking table. For this purpose, two shaking table experiments were selected as a case study. Shaking table experiments were carried on 1:1 scaled prototype one bay one storey RC structure with infill walls. The purpose of this shaking table experiment sequence is to assess local behavior and progressive collapse mechanism. Frequency decrease and eigen-vector evolution are directly related to in-plane and out-of-plane bearing capacities of infill wall enclosure with reinforced concrete frame. Firstly, frequency decrease-damage relationship was evaluated on the base of experiment results. Then, frequency decrease and stiffness degradation were evaluated with applied Peak Ground Acceleration (PGA) by considering strength deterioration. Lastly, eigenvector evolution-local damage and eigenvector evolution-frequency decrease relationship was investigated. Five modes were considered while evaluating damage and frequency decrease of the tested specimens. The relationship between frequency decrease, stiffness degradation and damage level were presented while comparing with Unreinforced Brick Infill (URB) and Reinforced Infill wall with Bed Joint Reinforcement (BJR) on the base of natural vibration frequency.

• Earthquakes and Structures
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• v.22 no.4
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• pp.331-343
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• 2022

Masonry structures are the most common structural systems that have been used almost all over the world from the earliest ages of history to the present day. These structural systems are often unfavorably affected by natural disasters such as earthquakes. The main reason for this is that they are built without sufficient engineering knowledge. On January 24, 2020, a severe earthquake occurred near the Sivrice District of Elazığ in eastern Turkey. According to the Turkish Directorate of Disaster and Emergency Management (AFAD), the magnitude of the earthquake was 6.8 and the focal depth 8 km. This earthquake caused damage and destruction to the masonry structures used extensively in the region. The Hacı Yusuf Taş (new) mosque in the Malatya city center, located about 64 km from the epicenter of the earthquake, was among the buildings affected by the earthquake. The mosque has smooth-cut stone walls and domes made of brick units. The main dome of the structure was severely damaged during the earthquake. In this study, information about the earthquake is first provided, and the damage to the mosque is then interpreted via photographs. In addition, two separate finite element models were produced, where the current state of mosque and solution suggestions are presented, and response spectrum analyses were carried out. According to these analyses and field observations, a buttress system to the main walls of the structure should be constructed in the direction which has little lateral rigidity.

• Explosives and Blasting
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• v.29 no.2
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• pp.67-80
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• 2011

Recently, the number of structure demolitions has increased in both civil and architecture fields due to various reasons such as redevelopment of a city, utilization of sites and restoration of deteriorated structures. In the past, domestic shell structures had been constructed with brick masonry and they were not high. Therefore, their demolition had been executed with ease. Recently, however, taller reinforced concrete shell structures have become a target for the destruction. Under these circumstances, how to efficiently demolish a structure and how to minimize effects of the destruction on environment including vibration and noise have become a main issue. One of the possible solutions is the explosive demolition. In this study, a case of explosives demolition of the stack, which is located in Jeju Thermal Power Plant in Republic of Korea and is 70 m tall, is addressed. In order to fall down the structure against the desired direction, 13.5 kg dynamite and 100 electric detonators were used.

• Earthquakes and Structures
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• v.16 no.4
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• pp.501-512
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• 2019

In this study, seismic vulnerability assessment and seismic isolation retrofit of Bayburt Yakutiye Mosque is investigated. Bayburt Yakutiye Mosque was built in the early 19th century at about 30-meter distance to Coruh river in the center of Bayburt in Turkey. The walls of historical masonry structure were built with regional white and yellow stones and the domes of the mosque was built with masonry bricks. This study is completed in four basic phases. In first phase, experimental determination of the regional white stone used in the historical structure are investigated to determine mechanical properties as modulus of elasticity, poison ratio and compression strengths etc. The required information of the other materials such as masonry brick and the regional yellow stone are obtained from literature studies. In the second phase, three dimensional finite element model (FEM) of the historical masonry structure is prepared with 4738 shell elements and 24789 solid elements in SAP2000 software. In third phase, the vulnerability assessment of the historical mosque is researched under seismic loading such as Erzincan (13 March 1992), Kocaeli (17 August 1999) and Van (23 November 2011) earthquakes. In this phase, the locations where damage can occur are determined. In the final phase, rubber base isolators for seismic isolation retrofit is used in the macro model of historical masonry mosque to prevent the damage risk. The results of all analyses are comparatively evaluated in details and presented in tables and graphs. The results show that the application of rubber base isolators can prevent to occur the destructive effect of earthquakes.

• Korean Journal of Heritage: History & Science
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• v.42 no.2
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• pp.154-169
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• 2009

Korea is famous for a number of stone pagodas. In particular, it is noticeable that the stone pagodas came after wooden pagodas in all the Kingdoms of Goguryeo, Baekje, and Silla. Since the advent of wooden pagodas, it was during the latter half period of Three Kingdoms(especially, in the early Seventh century) that the first stone pagoda appeared at Mireuksa Temple site in imitation of the wooden ones. Now that no one can deny that Korean stone pagodas have developed, imitating the wooden pagodas. It is also obvious that the Stone Pagoda at Mireuksa site is the prototype of Korean stone pagodas. However, this study casts doubt on the theory that the stone pagodas in the Silla Kingdom originated not from the wooden pagodas, but from the brick pagodas, whereas the stone pagodas in Baekje Kingdom which has been said to come from the wooden ones. The fact that the temples and pagodas in both Baekje and Silla were erected by the same builders and technicians is one of the evidences supporting the assertion of the study. This study, accordingly, examines on the origin of the Silla pagodas by supposing the two genealogies. The first one can be summarized in chronological order as follows: starting from wooden pagodas, Stone Pagoda at Mireuksa site, Stone Pagoda at Jungrimsa site, Stone Pagoda at Gameunsa site, and Stone Pagoda at Goseonsa site. The second one, on the other hand, runs as follows: starting from bick pagodas, Stone Pagoda at Bunhwangsa, Uiseong Tapri five-storied Stone Pagoda, Seonsan Jukjang-ri five-storied Stone Pagoda, and Seonsan Naksan-ri three-storied Stone Pagoda in order. As the above genealogies show, the origin of the stone pagodas has been an controversy, especially because of the two different points of view: the one is that the roof-supporting strata(Okgaesuk-Bachim) originated from the brick structure and the ancient tomb ceiling of Goguryeo Kingdom, and the other is that the strata is a sort of the simplified design of the wooden roof structure. This study, however, takes note of the difference in length of the strata between the brick pagodas and the stone pagodas; the former stretches out its strata longer than the latter. Consequently, the study points out that the roof-supporting strata of the stone pagodas is originally a sort of modification of the wooden roof structure.

• Journal of Conservation Science
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• v.6 no.1 s.7
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• pp.61-70
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• 1997

An integrated geophysical survey was conducted to study a construction method of the Sonsanri tombs including the Muryong royal tomb. With the distribution of soil resistivity and self potential values, the boundary between original ground and the construction site was delineated clearly. The original ground has relatively high resistivity of $1,000\~1,500$ ohm-m and low self-potential values of $0{\pm}3mV/m$, while the construction site has low resistivity less than 200 ohm-m and quite high self-potential values of $-20\~30mV/m$. It is interpreted that the open site for construction of subsurface tomb has the size of about 35 m in the north-south direction. Big difference in characteristics of ground between the tomb site and the original site gives a clue for the construction method of tombs in Baekje dynasty. The site was opened about 35 meters in the north-south direction and then a mold structure was constructed with a brick frame outside. The brick frame consists of bricks cemented each other and structually combined. The mold structure was removed from inside after refill of the opened construction site with some cemented rock debris and soil.

• Korean Journal of Heritage: History & Science
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• v.47 no.2
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• pp.68-84
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• 2014

The royal tombs of Baekje(백제), after the transfer of the capital to the Geumgang(riv)(금강) basin, changed to Songsanri(송산리) style(stone chamber) ${\rightarrow}$ Southern dynastic(남조) style(brick chamber) ${\rightarrow}$ Neungsanri(능산리) style(stone chamber). The most special feature of this process is the change of the ceiling structure. The ceiling had been changed from dome(Songsanri style) ${\rightarrow}$ tunnel ceiling(transition period of brick tombs and Neungsanri style) ${\rightarrow}$ a roof style(is Neungsanri style of three imitate type, trapezoid, triangle, flattened ceiling). The most special feature among this process is Neungsanri style(stone chamber), created especially in Baekje. The royal tombs of Baekje didn't lay stress on the mound, so the mound is not noticeable. It is result that they more stressed on basin of the boundary than showed off individual tomb, and this is count as an element of China Southern dynasty. Boundary of the royal tomb of Baekje, after the transfer of the capital to south, were changed from royal family's boundary to single independent's. Those are Songsanri's and Neungsanri's, these are the pair tombs(쌍릉) of Iksan(익산). That is influence of the Southern dynasty, reflect the theory of divination based on topography completely, this is influence of the China Sui(수) and the early Tang(당) dynasty's system of boundary of the royal tomb. Besides the royal tomb, they also buried a closely related person, in the boundary of the royal tomb. And facilities for memorial ceremony were existed too. An altar was equipped in Songsanri's boundary of the royal tomb, it was seen a kind of character of a sanctuary for progenitor. Neungsanri's boundary of the royal tomb were equipped with an open-aired altar that performed memorial ceremony about communal royal tombs, and also equipped a temple, was needed to pray for the happiness of the dead. This structure and arrangement are very similar to Seoakdong(서악동) of Silla(신라).

• Journal of architectural history
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• v.18 no.6
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• pp.127-144
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• 2009

This thesis aims to analyze the architectural form for the restoration of noogak(樓閣), Boje-roo(普濟樓) which was constructed at the central court of Beomeo-sa(梵魚寺). The results are as follow; 1. Boje-roo was established in 1700. By the constructional records and poetic essays of the times, the architectural of the establishment building was consisted fo two stories structure. The passage system for the approach to the court was the nuha-jinip(樓下進入), that is to say, one might walk between the columns of lower story of the building. And one could ascent the upper stairs and approach to the upper level, inner court. 2. By the remodelling in 1812, the building was varied to one story structure. Therefore the passage system for the approach to the inner court transformed from the nuha-jinip to the ugak-jinip(隅角進入), that is to say, one might ascent the atairs of the podium and could approach the inner court through the both sides of the building. 3. Under the Japanese imperialistic rule, the structure of it's roof and walls of Boje-roo were altered to the Japanese style. In 1965, the wooden columns were shifted to the concreted column, and the wooden wall-panels were shifted to the brick wall attached stone slates. 4. Conclusively speaking, for the restoration of Boje-roo, the establishment form in 1700 is the more proper than the remodelling form in 1812.

• Korean Institute of Interior Design Journal
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• v.24 no.6
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• pp.13-21
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• 2015

The purpose of this study is to analyze the changing housing construction in Jeju-do which is composed of two cities(Jeju-si, Seogwipo-si). The number of indigenous population and migrating population of Jeju-do has been increasing every year because it has more beautiful scenery, interesting culture and a higher ratio of natural green area to urban area than other provinces(inland). More than 70% of population in Jeju-si is concentrated in dong-area. As a result, urban area and commercial area are expanding in entire Jeju-do. On the other hand, green area and non-urban area of Jeju-do are decreasing steadily. And there was a lot of changing during a short of time after 2010 because of internationalization and urban development etc.. This study is an analysis about the changing of housing in Jeju-do by statistical data. As a results of the analysis. I discovered that 1) The supply ratio of available housing in Jeju-do is higher than other inland cities in other parts of the country. 2) Housing constructing is influenced by moving-in and moving-out population. 3) There are more detached houses in Jeju-do than apartments. The opposite phenomenon occurs in other provinces (inland cities). However, the number of detached houses is gradually declining in Jeju-do since 2000. 4) Most detached homes in Jeju-do have an area of $60m^2{\sim}90m^2$. Most apartments have smaller areas than $60m^2{\sim}90m^2$. Seogwipo has homes with a larger area than Jeju-si. 5) The ratio of concrete structure houses is increasing at high speed because of constructing of apartment buildings, on the other hand, the ratio of brick structure house is decreasing gradually. Finally, Even though Jeju-do has different from housing culture of inland, it is changing slowly like inland housing types.