• Journal of Conservation Science
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• v.29 no.2
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• pp.149-159
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• 2013

The painted folding screen of Crown Prince Munhyo at Boyangcheong, Munhyo-seja Boyangcheonggyebyung, was made to record the court ceremony where Crown Prince Munhyo(1782-1786), the firstborn son of King Jeongjo, met his first teacher called Boyanggwan for the first time at Boyangcheong, a government agency specifically founded to provide education for a crown prince, in January 1784. Having never been treated before, this 8-fold screen is still in its original presentation of Joseon Dynasty screen paintings of court ceremonies in the 18th century. The mountings of folding screens in Joseon Dynasty has been researched through the study of the mounting of the Boyangcheong screen and the conservation treatment of the screen has been based on this research. The result of the pigment analysis shows the use of lead white, red lead, vermilion(cinnabar), azurite, malachite, litharge(massicot), carbon black(Chinese ink). The microscopic observation has proved that the painting was painted on verso in most areas and finished on recto to highlight the details or to produce subtle hues by applying light colors.

• Journal of Conservation Science
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• v.32 no.4
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• pp.571-578
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• 2016

This study analyzed the pigments used in two portraits of Sim Hui-su using scanning electron microscopy/energy dispersive spectroscopy(SEM/EDS), X-ray diffraction(XRD) analysis, and microscopic observation, and then compared the results to those from nondestructive analysis. It was estimated that cinnabar/vermilion and minium were used for the red pigment, azurite for the blue pigment, atacamite for the green pigment, and lead white for the white pigment. These results were compared to the pigments of six portraits with a similar format, full-length official-attire portraits from the $17-18^{th}$ century Joseon period. It was revealed that the composition of the pigments used in the portraits varied depending on the date of production. Iron oxide, another red pigment, was used in the $18^{th}$ century. As for the blue colorant, smalt was used in the late $18^{th}$ century, whereas it was absent until the early $18^{th}$ century.

• Journal of Korean Society of Steel Construction
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• v.15 no.6 s.67
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• pp.649-660
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• 2003

The paper presents an evaluation of the tensile strength of the expansion anchor that can cause failure in the concrete based on the design of the anchorage. Tests of the heavy-duty anchor and the wedge anchor that are domestically manufactured and installed in plain concrete members are conducted to probe the effects of the embedded depth, concrete strength, and anchors spacing. The design of post-installed steel anchors is presented using the Concrete Capacity Design (CCD) approach. The CCD method is applied to predict the concrete failure load of the expansion anchor in plain concrete under monotonic loading for important applications. The concrete tension capacity of the fastenings with heavy-duty anchors and wedge anchors in plain concrete predicted using the CCD method is compared with the test results. For the CCD method, a normalization coefficient of 9.94 is appropriale for the nominal concrete breakout strength of an anchor or a group of wedge anchors in tension. On the other hand, a normalization coefficient of 11.50 is appropriate for the nominal concrete breakout strength of an anchor or a group of heavy-duty anchors in tension.

• Journal of Korean Society of Steel Construction
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• v.26 no.1
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• pp.21-30
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• 2014

In this study, an experimental study was performed to evaluate the shear resistance of cast-in-place(CIP) anchors reinforced with hairpin and stirrup bars under static and dynamic loads. The reinforcement was developed using D6 bars, and the anchors were installed with 20mm diameter and 120mm edge distance. Three tests were conducted for each type of reinforced anchor under static and dynamic shear load with a pulsating frequency of 1 Hz, respectively. It was found that the strength of hairpin-reinforced anchor was affected by the concrete cover and the dynamic tests showed no capacity reduction of anchors compared with static tests. The stirrup-reinforced anchor showed little increase of resistance compared with unreinforced anchor and the resistance under dynamic loading showed nearly same strength by static loading.

• Journal of Korean Society of Steel Construction
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• v.26 no.1
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• pp.11-20
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• 2014

The Concrete Capacity Design(CCD) method has been used in the design of anchor since 2001 and Korean design code specify that concrete breakout capacity of CIP anchor under seismic load shall be taken as 75% of static capacity. In this study, an experimental study was performed to evaluate the concrete breakout capacity of unreinforced CIP anchors under dynamic shear force. For the purpose, three static and dynamic shear-loading tests were conducted using 20mm diameter anchors, respectively. The edge distance of 120mm was considered in the tests. In the dynamic tests, 15 cycles pulsating load with 1Hz speed was applied and the magnitude of loading step was increased until concrete breakout failure occurs. From the tests, the concrete breakout capacity under dynamic shear loading showed nearly same capacity by static loading.

• Conservation Science in Museum
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• v.14
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• pp.13-22
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• 2013

The Nectar Ritual Painting(Jeung7551) in National Museum of Korea is estimated to have been produced in the 16th century. Ezimagodo who is the head priest of Ruganji in Kyoto, Japan donated this painting in 2010. Overall, damages were serious, such as missing, staining, folding, insects of the face and mounting silk, therefore, it need to conservation treatment. The treatment of conservation in painting was removing surface stains and repairing missing area. It was mounted by following the original form. The analysis result of textile in mounting and support fiber used silk and hemp in microscope. Pigments in paint were divided into six color types. This painting was used that vermilion(cinnabar) and red lead for red color, litharge(massicot) and gold for yellow color, lead white for white color, malachite for green color, azurite for blue color, and carbon black(chinese ink) for black color.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.158-165
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• 2019

The purpose of this study is to investigate analytically the flexural behavior of beam reinforced by an alkali-activated slag-based fiber-reinforced composite. The materials and mixture proportion were selected to manufacture an alkali-activated slag-based fiber-reinforced composite with high tensile strain capacity over 7% and compressive strength and tension tests were performed. The composite showed a compressive strength of 32.7MPa, a tensile strength of 8.43MPa, and a tensile strain capacity of 7.52%. In order to analyze the flexural behavior of beams reinforced by ultra-high-ductile composite, nonlinear sectional analysis was peformed for four types of beams. Analysis showed that the flexural strength of beam reinforced partially by ultra-high-ductile composite increased by 8.0%, and the flexural strength of beam reinforced fully by ultra-high-ductile composite increased by 24.7%. It was found that the main reason of low improvement in flexural strength is the low tensile strain at the bottom of beam. The tensile strain at bottom corresponding to the flexural strength was 1.38% which was 18.4% of tensile strain capacity of the composite.

• Journal of Conservation Science
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• v.36 no.6
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• pp.519-532
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• 2020

This study aimed to interpret the coloring materials recorded in the ceremonial writing with the scientific investigation results of the Hanging Painting of the Chiljangsa Temple (Five Buddhas). The results confirm that the Jinboon, Joohong, Hwangdan, Hwanggeum and Seokjahwang are clearly connected to lead white, cinnabar, minium, gold, and orpiment, respectively. Danghayeop and samrok are related to Copper trihydroxychloride, while Daecheong and Joongcheong are azurite, and they seems to be classified by the particle size. Yeonji and Chunghwa are organic dyes in red and blue, respectively, with blue confirming the existence of the side, but Yeonji differs from the names of the ancient texts and Chinese characters; it is unclear whether it is a commonly used Yeonji because of differences in the names of the ancient texts. The presence of Sootohwang has not been confirmed in the gwaebultaeng, but it can be extracted from the soil as a yellow-colored material but the possibility of Deunghwang cannot be ruled out.

• Korean Journal of Construction Engineering and Management
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• v.23 no.2
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• pp.45-53
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• 2022

The purpose of this study is to present a model for analyzing construction errors of reinforced concrete pile foundations using drones. First, a drone is used to obtain an aerial image of the construction site, and an orthomosaic image is generated based on those images. Then, the circular pile foundation is automatically recognized from the orthomosaic image by using the Hough transform circle detection method. Finally, the distance is calculated based on the the center point of the reinforced concrete pile foundation in the overlapped data. As a case study, the proposed concrete concrete pile foundation construction quality control model was applied to the real construction site in Incheon to evaluate the proposed model.

• The Korean Journal of Applied Statistics
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• v.35 no.1
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• pp.119-129
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• 2022

In this paper, we predict the earthquake magnitudes which were recently occurred in Gyeongju and Pohang, using statistical methods based on historical data. For this purpose, we use the five-year block maximum data of 1392~1771 period, which has a relatively high annual density, among the historical earthquake magnitude data of the Chosun Dynasty. Then, we present the prediction and analysis of earthquake magnitudes for the return level over return period in the Chosun Dynasty using the extreme value theory based on the distribution of generalized extreme values (GEV). We use maximum likelihood estimation (MLE) and L-moments estimation for parameters of GEV distribution. In particular, this study also demonstrates via the goodness-of-fit tests that the GEV distribution can be an appropriate analytical model for these historical earthquake magnitude data.