• Fire Science and Engineering
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• v.30 no.3
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• pp.55-61
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• 2016

In this study, to determine whether it is possible to apply Polyethylene (PE) compound pipe, which was developed to solve the problem caused by the corrosion of the fire protection piping currently in usein water based fire extinguishing systems, we performed an actual mockup fire test. Since no test standard was available related to the developed compound pipe, we compared and analyzed domestic and international technical materials and test standards and selected suitable fire test standards to evaluate the performance of the PE compound pipe. we applied two fire test standards to the PE compound pipe, viz. those for CPVC and metallic pipes, and conducted a total of 6 experiments to evaluate its performance. According to the results of the first and second fire tests based on the test standard for the CPVC pipe, neither the fitting nor the piping was damaged or deformed and no leakage was observed in the pressure test, which was performed for 5 minutes. For the fire test based on the metallic pipe test standard, a total of 4 experiments were conducted. The first two experiments were conducted to simulate the wet piping system. In the results of this fire test, neither leakage nor rupture was observed from the PE compound pipe and no damage was caused, such as the secession of the PE material. However, in the next two experiments, which simulated the dry system, the PE compound pipe suffered damage and rupture, including deformation before the fire fighting water was discharged. Therefore, we found that the piping performance of the PE compound pipe did not undergo any deterioration, including fusion, deformation, or damage, in the wet piping system simulated fire test.

• Journal of the Korea Institute of Building Construction
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• v.14 no.2
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• pp.127-134
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• 2014

This study had the goal of analyzing the economic feasibility and constructability of a fire resistant curtain wall system using Light-weight Inorganic Composite Foam Board(LI-CFB). LI-CFBs, new materials with excellent fire resistance are being developed for use as the back panel of curtain wall and their fire resistance has already been analyzed through actual tests in earlier studies. In this study, a mock-up test involving the installation of the fire resistant curtain wall system on an actual building was conducted, and the system was compared with a common curtain wall system. This system is applied in the same way as a common curtain wall system. But the cutting LI-CFBs, which are brought from a factory, are used in the system and attached on the frame (mullion and transom). Even though the system requires more working time than the existing system, the LI-CFBs back panels are easy to cut and do not produce dust. Also, the panels are able to be assured the quality by checking damaged parts easily. Besides having a high level of fire resistance, the system's economic feasibility and constructability meets or exceeds those of the existing system.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.1
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• pp.33-40
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• 2019

The purpose of this study is to analyze historical records of what the trees had been planted like by establishment and management of the Royal Tombs of the Joseon Dynasty so that it could be utilized for historical records to manage the trees in the Royal Tombs. The research method was to analyze the related keywords for 40 trees out of 42 trees in the Royal Tombs of the Joseon Dynasty reffering to "The Annals of the Joseon Dynasty(朝鮮王朝實錄)," and "Neungji(陵誌)". There are two types of planting called Jeongsik(定植) Bosik(補植) in the Royal Tombs. Jeongsik(定植) is a planting method by Salleungdogam(山陵都監), the office in charge of construction of the royal tomb when they were building the royal tomb. Every tree additionally planted after building up the royal tomb was called Bosik(補植). The types of tree planting the composition and management of the royal tombs of Joseon are as follows. First, the first planting for landscaping was carried out during the process of building the province. Second, after the formation of Shanung, all the plants were planted by Wangmyung as additional plants. Third, due to the deforestation in the late Joseon period, additional plants were planted in the fertile plains. Fourth, trees were damaged due to natural disasters, and trees were planted together with the construction of the botanical gardens. Fifth, in the 22nd year of King Jeongjo, all the royal families' graves were regularly planted. This study aims to investigate the history of forest landscape management for the restoration of the royal tombs of Joseon.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.138-145
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• 2023

Purpose: In accordance with the increase in the number of buildings repaired and reinforced following deterioration from when a fire occurs in a previously reinforced building, the impact on the structure after the fire is analyzed to establish standards for repair and reinforcement measures. Method: After curing for 28 days, the process was to measure the compressive strength and induce destruction through a compressor, repair and reinforce it with epoxy, and conduct a re-compressive strength test on some specimens after curing for 3 days to understand the degree of strength restoration. The rest of the repaired and reinforced specimens as well as the unrepaired and unreinforced specimens were then put into an oven and heated according to the temporal and temperate conditions listed below, and then the compressive strength was tested to estimate the impact of fire. Result: After reinforcing the yielded specimen with epoxy, the process was to then put it in an oven and heat it at different temperatures over time. It was found that there was a decrease in the strength of the reinforcement more than that of the actual specimen. Conclusion: Based on this, it was found that a building repaired and reinforced with epoxy resin is actually more dangerous than a general unrepaired building when it is damaged by fire, and thus, that it must be prepared for fire vulnerabilities.

• Journal of Korean Society of Disaster and Security
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• v.16 no.2
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• pp.75-83
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• 2023

In general, bridges are facilities installed for the purpose of easily passing through sections such as valleys and rivers. Railway bridges that run through downtown areas are damaged due to external factors such as earthquakes and collisions with passing vehicles, resulting in serious human casualties. This can cause serious human and properties damage, such as functional paralysis in downtown areas. Depending on the degree of damage, repair work such as partial repair or full replacement is in progress for the bridge where the collision occurred. When damage or deformation occurs due to collision, the repair method is determined according to the degree of deformation and the degree to which the load capacity of the bridge is affected by the deformation. In this study, a numerical analysis review was performed on the repair work for the local deformation caused by the collision of a vehicle on an old railway bridge installed and in operation in an urban area. To this end, a structural safety review of the bridge for local deformations caused by vehicle collisions was conducted. In this paper, a repair method for the accident bridge was presented based on the analysis results.

• Journal of the Korean Geotechnical Society
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• v.40 no.3
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• pp.77-84
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• 2024

Aging and damaged underground utilities cause cavity and ground subsidence under roads, which can cause economic losses and risk user safety. This study used infrared cameras to assess the thermal characteristics of such cavities and evaluate their reliability using a CNN algorithm. PVC pipes were embedded at various depths in a test site measuring 400 cm × 50 cm × 40 cm. Concrete blocks were used to simulate road surfaces, and measurements were taken from 4 PM to noon the following day. The initial temperatures measured by the infrared camera were 43.7℃, 43.8℃, and 41.9℃, reflecting atmospheric temperature changes during the measurement period. The RP algorithm generates images in four resolutions, i.e., 10,000 × 10,000, 2,000 × 2,000, 1,000 × 1,000, and 100 × 100 pixels. The accuracy of the CNN model using RP images as input was 99%, 97%, 98%, and 96%, respectively. These results represent a considerable improvement over the 73% accuracy obtained using time-series images, with an improvement greater than 20% when using the RP algorithm-based inputs.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.1
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• pp.31-40
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• 2015

This study aims to comprehend that Seokpajeong garden for aspect of space change. Spatial characteristics according to the transfer of ownership are classified as period. And investigate the aspect of space change in Seokpajeong garden based on literature and painting, newspaper, photo. The results were as follows. First, Investigate the construction and change of Seokpajeong garden. Accordingly, spatial characteristics of Seokpajeong garden are classified into three period. 1st period is Kim-Heung Keun owned Samgyedong-jungsa garden. 2nd period is Daewongun hold Seokpajeong garden. 3rd period is damaged original form of Seokpajeong garden from Korean War to current time inclusive. Secondly, Kim-Heung Keun owned Samgyedong-jungsa garden has characteristics of water system centric space and many buildings. In addition accept foreign culture like chinese pavilion and Byeoldang Villa. and plant unique flower and leaf in garden. Thirdly, According to Seokpajeong garden folding screen, Daewongun owned Seokpajeong garden accept organization of space in Samgyedong garden. But different locations of Sarangchae in folding screen means possibility of move building to current position. So, additional historical research is required with representation of chinese pavilion location. Fourthly, Seokpajeong garden was damaged from original form to frequent changes of ownership. Transform of geographical features and water system as well as Anchae and Sarangchae, back side of a outbuilding are only the remained among many buildings. Also, Seokpajeong garden is more fell to the subsidiary facility of Seoul Museum than Wonrim. Therefore restoration and recovery of original form are urgent.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.431-438
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• 2016

Recently, Both rapid economic growth and high-quality native finishing materials demand in buildings such as local infrastructure facilities and cultural facilities have increased along with local quarries. So, increasing local quarries and environmental pollution occurred in quarries get the eyes to damaged area of the surroundings. As an example, carcinogen such as solid formed to fixing asbestos and dust have damaged to local resident. Especially, Radon gas released from asbestos can exist everywhere on earth, released soil and rock as radioactive substances, can be caused lung cancer followed by a smoking. When pollution source to indoor air quality that lacking ventilation rate of the residential building moved in a cycle, human responses such as headache, dizziness, etc. get appear, so on it threatened resident's physical condition. Thus, we need to urgent attention to reduction harmful substance. In the case of radon gas of the pollution source to indoor air quality in housing, it has characteristic that keep on going through half-life released from source, we need to control radon gas source than source removal. We set on vermiculite addition ratio to 10% which has harmful substances adsorption performance, proceed experiment to basalt waste rock addition ratio 50, 60, 70, 80(%). The result of an experiment, based on 'KS F 4035, precast terrazzo', we can be obtainable in the best terrazzo at basalt waste rock addition ratio 70%.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.2
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• pp.31-41
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• 2020

Since its foundation in the unified Silla period, Sunam Temple in Jeollanam-do has well preserved its reputation as a representative temple in Honam. However, during the course of history as the temple went through many changes and development, much of its landscape identity were lost or damaged. At present, we found that some of distinctive features as traditional Korean temple are lost or damaged in Sunam temple and in some cases, Japanese style features were applied which calls for urgent restoration to the original landscape style. We found that vegetation pattern of Sunam temple was quite different from those of traditional Korean temples and garden components were rather similar to Japanese garden style. There are two reasons why these changes occurred to Sunam-temple. The first reason is changes made to the temple by Japanese people during the Japanese occupation period in Korea. The second is the renovation effort of the entire temple in 1976. The study aimed to examine landcape changes of Sunam temple in detail and understand Japanese style landscape components and methods applied to the Sunam temple to untimately understand landscape identity of Sunam temple. On-site research, literature research and interviews with monks were conducted and we found that Sunam-sa Temple was significantly influenced by the landscape style of Japan, and that more Japanese-style landscapes were produced while trying to hide these elements. However, this study was limited in understanding the very original landscape form of Sunam temple before the Japanese coloniral era.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.74-79
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• 2020

Safety inspection of cable-supported bridge has increasingly attention as many cable-supported bridges are currently constructed/operated. Whilst cables as a main component in cable-supported bridge should be inspected regularly, traditional method (visual inspection) has limitation to check the condition of cables properly due to restricted factors. It is evidently necessary to develop cable-inspection robot to overcome this concern. In this respect, the main aim in this study is to manufacture the improved robot compared with the existing robot. The improved functions of the robot in this study were that the robot can be operated in large cable diameter (greater than 200 mm) and climbing ability of the robot increases. In addition, electro-magnetic sensor as a non-destructive method in the robot was added to detect damaged cables and performance of the sensor was evaluated in indoor and field experiments. Consequently, the robot was able to move on the cable with ~0.2m/s and to detect damaged cables using the sensor. It was also confirmed that performance of the robot in field test is similar to that in indoor test.