• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.101-113
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• 2022

This study is planned with the aim of developing a systematic construction process based on the scientific and engineering theory of the water-sealing grouting construction applied to the tunnel excavation process during the construction of the downtown underground traffic network, so that the construction quality of the relatively backward domestic tunnel water-sealing grouting construction is improved and continuously maintained no matter who constructs it. The main contents of the improved tunnel water-sealing grouting can be largely examined in the classification of tunnel water-sealing grouting application and the definition of grouting materials, the correlation analysis of groundwater pressure conditions with groundwater inflow, the study of the characteristic factors of bedrock, and the element technologies and injection management techniques required for grouting construction. Looking at the trends in global research, research in the field of theoretical-based science and engineering grouting is actively progressing in Nordic countries (Sweden, Finland, Norway, etc.), Japan, Germany, and the United States. Therefore, in this study, the algorithm is established through theoretical analysis of the elements of tunnel water-sealing grouting construction techniques to provide an integrated solution including a construction process that can effectively construct tunnel water-sealing grouting construction.

• Conservation Science in Museum
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• v.29
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• pp.153-162
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• 2023

Clay figure of Baekje, produced by forming and molding various shapes using clay, are mainly excavated from temple sites and provide essential information for studying the Buddhist art of Baekje. Research on clay figures of Baekje primarily focuses on the characteristics of Baekje-era temples in which such figures are excavated, as well as the role and production techniques of clay figures, by comparing regional and morphological characteristics. In particular, research on the manufacturing method of clay figures is mainly carried out by visual observation, whereas precise scientific analysis is required to understand production techniques and characteristics of raw materials in greater detail. In this study, to confirm such production techniques and material characteristics, computed tomography (CT) scans were conducted on the Clay Bodhisattva excavated from the Neungsan-ri Temple site in Buyeo. As a result, it was found that the Clay Bodhisattva was made using a cylindrical core of fine clay, tied together with several thin branches or reeds with straws. The clay used in the figure bore traces indicating the presence of herbaceous plants, which increase adhesion between clay and prevent cracks in the contraction process. On the other hand, the density of the fine clay differs on the inside and outside of the clay figure. Based on this, it is presumed that the clay was applied around the cylindrical core to shape the Clay Bodhisattva. The clay was reapplied on top of the figure to express the detailed shape and pattern.

• Journal of Conservation Science
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• v.31 no.3
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• pp.181-192
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• 2015

This study aims to examine production technique of twelve white wares from the Gangneung Namyang-ri and Donghae Balhan-dong2(Samun-dong) kiln sites, Kangwon Province and characteristics of the used materials, and to find a correlation among materials of the excavated white wares. X-ray fluorescence sequential spectroscopy(XRF), X-ray diffraction(XRD), Dilatometer and Inductively coupled plasma mass spectrometry(ICP-MS), Inductively coupled plasma automic emission spectrometer(ICP-AES) were applied to determine the chemical composition, crystalline phase of samples, firing temperatures, trace elements and rare earth elements. When analyzing body crystalline phases of the white wares using the XRD method, quartz and mullite were extracted from all the samples. Though firing temperature of each sample was different, they were mostly fired at a temperature below $1200^{\circ}C$. Analyzing the excavated white wares using the Seger formula, compositional properties of white wares in Gangneung Namyang-ri kiln showed diffrently from the Donghae Balhan-dong2(Samun-dong) kiln. The body of white wares from Gangneung Namyang-ri kiln have higher raito of $RO_2$ and $RO+R_2O$ than of white wares from Donghae Balhan-dong2(Samun-dong) kiln site. The white wares from Gangneung Namyang-ri kiln and Donghae Balhan-dong2(Samun-dong) kiln were made of host rocks of the different geological origin, according to the result of rare earth elements analysis.

• Journal of Conservation Science
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• v.35 no.5
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• pp.508-517
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• 2019

This study analyzed on alloys and by-product samples produced through the reproduction experiment of bronze mirror with geometric designs. The alloy ratio used in the first and second reproduction experiments was based on the analysis results of bronze mirror with geometric designs(Cu 61.68%, Sn 32.25%, Pb 5.46%) which is the national treasure No. 141. As a result of portable X-ray fluorescence analysis on the raw materials used in the reproduction experiment, the contents of copper raw materials were 98.85 wt% for Cu, tin raw materials were 99.03 wt% for Sn, and lead raw materials were 70.19 wt% for Pb, and 21.81 wt% for Sn. Sn and Pb were added 5 wt% more considering the evaporation amount of tin and lead during alloy melting. The result produced by the first reproduction experiment were 58.75 wt% for Cu, 36.87 wt% for Sn, 4.39 wt% for Pb, and the other result produced by the second reproduction experiment were 58.66 wt% for Cu, 35.89 wt% for Sn, and 5.50 wt% for Pb. The composition of the components was about 3.00 wt% in Cu and Sn respectively, and the microstructure was similar to the previous studies because the δ phase was observed mainly. The results of this study will be used as basic data for the materialistic characteristics of ancient bronze mirror in the future.

• Journal of Conservation Science
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• v.35 no.6
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• pp.631-640
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• 2019

The purpose of this study was to compare analytical results of sand iron bars reproduced by the traditional iron-making method through a destructive analysis and a non-destructive analysis. For these studies, we produced two types of samples. One was sample(SI-A), a part of the sand iron bar for destructive analysis. The other was SI-B(9 ㎠) for non-destructive analysis. A metallurgical microscope and scanning electron microscope were used for the destructive analysis, and neutron imaging analysis with the Hokkaido University Neutron Source (HUNS) at Hokkaido University, Japan, was used for the non-destructive analysis. The results obtained by destructive analysis showed that there was ferrite and pearlite of fine crystallite size, and some of these showed Widmanstätten ferrite microstructure grown within the pearlite and coarse ferrite at the edge of the specimen. The results from the neutron imaging analysis showed that there was also ferrite and pearlite with 3 ㎛ α-Fe of BCC structure. Based on these results, neutron imaging analysis is capable of identifying material characteristics without destroying the object and obtaining optimal research results when applying it to objects of cultural heritage.

• Journal of Conservation Science
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• v.27 no.3
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• pp.313-322
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• 2011

The floral wall of Lee Sang-beom's House and Atelier, which is No. 171 of the Registrated Cultural Heritage was conserved. In addition, materials characteristics and manufacturing technique have revealed through the scientific analysis. As a result of the analysis, samples were divided into three sections; the support layer that is made from block bricks, the paint layer and the cement mortar layer on the paint layer for the reinforcement of the construction. The higher layer lies, the finer grains it has. Furthermore, a little it was generated a small quantity of pores and calcium carbonates ($CaCO_3$) generated due to aeration of cement mortar. The patterns of letters, animals and plants pattern were expressed in the paint layer by relief and openwork. The results of qualitative analysis of the pigments of the paint layer were detected components of carbon black (C), Fe oxide ($Fe_2O_3$) and oyster shell white ($CaCO_3$, or quicklime). On the other hands, as the conservation of the floral wall, stainless frames were set up for the structural stability, the cement mortar were removed from the surface and the partly damaged and cracked areas were filled with KSE Filler A, B.

• Journal of Conservation Science
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• v.25 no.3
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• pp.299-316
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• 2009

The Goryeo roof tiles from the Oegol site in Tangjeong, Asan are classified into three groups in color such as gray, red yellow and gray-yellow groups, respectively. While each group of tiles shows characteristic specific gravity, absorption ratio, LOI and vitrification degree, mineral content and distribution, and chemical composition are generally homogeneous among all groups of roof tiles. Also, all roof tiles and soils from the site show similar geochemical behavior of elements and clay-mineralization degree. This indicates that the soil from the site is probable to be a raw material of the roof tiles. Firing temperature of the roof tiles is estimated as 950 to $1,050^{\circ}C$ for the gray group, 800 to $900^{\circ}C$ for the red yellow group, and 900 to $950^{\circ}C$ for the gray-yellow group. In conclusion, roof tiles from the Oegol site is interpreted to be made of local clay without additive minerals, applying various firing conditions and standardized purifying process of raw clay materials.

• Journal of Conservation Science
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• v.27 no.1
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• pp.31-40
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• 2011

Copper-red (Dongwha, Jinsa) is Korean traditional inorganic pigment used for red-coloring on the porcelain surface during Goryeo and Joseon Periods. Trace amounts of copper-red porcelains are handed down because of the technical difficulty of making and coloring of the pigment. It is known that copper ore sources were extensively distributed in Korea according to old literatures and some of them are still producing copper ore at this present. Main types of copper-bearing mineral in Korea are chalcopyrite ($CuFeS_2$) and malachite ($Cu_2CO_3(OH)_2$), and they are easily collected from the ground surface. This means Korea had geographical and economic geological advantages for supplying raw material of the pigment. These two minerals showed good red-coloring in color test for porcelain pigment. As a coloring element, copper showed micro size less than $5{\mu}m$ in diameter in glaze matrix. The dispersion of copper particle is the most decisive factor for red chromaticity of copper-red porcelain, as well as copper content of the pigment.

• Korean Journal of Heritage: History & Science
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• v.55 no.1
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• pp.51-61
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• 2022

Earthenware horn cups with horse head decorations were excavated from Tomb No. 7 of Bokcheon-dong, Dongraegu, Busan Metropolitan City. Made of earth in the shape of a horn, these cups are considered to have been used to drink alcohol or beverage. Large numbers of earthenware horn cups of various shapes were excavated from tombs located in the old territories of Silla and Gaya. A pair of earthenware horn cups were excavated from Tomb No. 7, and the two cups are almost identical in overall shapes and manufacturing techniques despite different sizes. Conservation treatment was carried out for the bigger one of the two horn cups this time. There are two cracks toward the horse head decorations around the mouth with missing parts observed. The chest of the horse touches the ground with one side decorating the horse head and the other side facing the conical mouth of the horn cup. It is in the U shape, striking a balance based on two legs attached behind. The surface of the horn cup was made with a potter's wheel, and the connection to the horse head has traces of cutting and trimming. The horse head is expressed realistically with its features including the ears, eyes, nose, and mouth well apprehended and its color is grey This study intended to investigate manufacturing techniques of the artifact by examining its internal structure through the condition survey in a non-destructive way. CT imaging was used to figure out its manufacturing techniques and to diagnose its condition, and accordingly the scientific conservation treatment was conducted to stabilize the artifact. The precise diagnosis on conservation condition found that there are two chips in the spout with their cracks extended. One of the chips is connected with separation added to the crack. The material which has been used for connection in the past was collected for the infrared spectroscopic analysis, which was identified to be nitrocellulose resin for the connection. Therefore, this conservation treatment focused on removing the old material and preventing the spread of cracks. Before conservation treatment, the condition survey and scientific examination for the artifact were carried out to secure data about the earthenware horn cup with horse head decorations(Treasure). Based on them, effective plans for its conservation treatment was sought for and then existing adhesive was safely removed, and restoration material was selected to take into account its reversibility. In addition, the conservation treatment according to optimal methodologies was conducted through the consultation meeting with experts.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.523-523
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• 2013

대기압 제트 플라즈마는 의료산업 및 재료공정, 정수, 기체흐름 제어 등 다양한 분야에 적용을 위한 연구가 활발히 진행되고 있다. 뿐만 아니라 구동 조건에 따라 다양한 방전 모드가 존재하며, 이에 따라 발생된 플라즈마의 광학적 및 전기적 특성도 매우 다르게 나타나기 때문에 과학적으로도 새로운 현상들이 속속 발표되고 있다. 대기압 제트 플라즈마에서 중요한 과학적 현상 중 하나인 스트리머(streamer) 혹은 플라즈마 총알(plasma bullet)은 수-수십 kHz의 저주파 전압으로 구동 시 특정 조건에서 발생하는 현상으로, 최근 들어 시간분해능이 높은 ICCD 카메라를 이용하여 스트리머의 발생 및 전파에 대한 새로운 현상의 발견과 다양한 물리적 이해가 시도되고 있다. 본 연구에서는 헬륨 대기압 제트 플라즈마에 포함된 질소 함유량에 따른 다중 스트리머의 발생 및 기작의 이해를 시도하였다. 구동 전압 및 주파수, 헬륨기체의 유량, 전극 구조 및 간격 등 모든 조건이 동일한 상태에서 질소기체의 함유량을 증가시킬수록 특정 영역에서 스트리머의 개수가 증가하는 것을 관찰되었다. 또한 $N_2{^+}$의 방출광 세기가 헬륨 및 산소 원자의 방출광보다 지배적인 것으로 측정되었으며, 이는 헬륨 플라즈마에서 흔히 나타나는 헬륨 metastable에 의한 질소분자의 페닝 이온화(Penning ionization) 때문이다. 본 연구팀은 페닝 이온화($He^*+N_2{\rightarrow}He+N_2{^+}+e$)로 인해 추가적으로 발생하는 전자가 다중 스트리머 발생에 중요한 역할을 하는 것이라 제안한다. 좀 더 심화적인 분석을 하고자 헬륨-질소 플라즈마에서 주된 여러 가지 반응식을 이용하여 페닝 이온화에 의한 이온화율 및 전자의 직접적인 충돌에 의한 질소, 헬륨의 이온화율의 계산을 수행하여 특정 영역에서 헬륨의 이온화율보다 질소 페닝 이온화율이 더 커지는 것을 확인하였다.