• Title/Summary/Keyword: JCS

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Ultrasonic Properties on Building Stones, Characteristics of Structural Deformation and Conservation States of the Sanctuary in Wat Phou Temple of Champasak, Lao PDR (라오스 밧푸 주사원의 보존현황과 석재의 초음파 물성 및 구조적 변형특성)

  • Lee, Chan Hee;Shin, Hyo Cheol;Han, Doo Roo
    • Journal of Conservation Science
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    • v.33 no.6
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    • pp.399-416
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    • 2017
  • The 'Wat Phou and Associated Ancient Settlements within the Champasak Cultural Landscape' of Laos was designated as a UNESCO World Cultural Heritage in 2001. The uppermost structure of the Sanctuary in Wat Phou has been destroyed and being variably damaged, maintenance is required through scientific and systematic diagnosis. The Sanctuary of Wat Phou was constructed mainly using sandstones and bricks. There are physical damages including fracture, break out, exfoliation and interval as well as biological damages by lichen, mosses and weeds. According to the ultrasonic velocity measurement and property evaluation of the sandstones of the Sanctuary in Wat Phou, weathering index of the eastern side sandstones is 0.10 to 0.74 (mean 0.36), showing MW grade. Southern and northern side sandstones have relatively higher properties with average weathering indices of 0.30 and 0.32. The results of slope analysis of the Sanctuary, indicated that the 4th spot in the southern side has the largest slope of $5^{\circ}W$, seemingly due to the unstable ground around the Sanctuary. Based on the relative level measurement and past drawings, the Sanctuary is verified to have been located on ground with a certain slope rather than flatland. The ground of the southern side is inclined $1.51^{\circ}$ more than that of the northern side, which will affect the structural stability of the temple. The interval width of the selected southern spot is the largest with an average width of 159.5 mm, and the largest width is 328.3 mm at the top, since the width increases above rather than below, seemingly due to the unequal subsidence of the ground. Constant maintenance for conservation is required for the structural stability of the Sanctuary in Wat Phou, which was partly collapsed and has also suffered physical damage.

Study on the Re-corrosion Characteristics of Corrosion Products by Weeping of Iron Artifacts (철제유물 Weeping에 따른 부식화합물의 재부식 특성 연구)

  • Park, Hyung-Ho;Lee, Hye-Youn;Lee, Jae-Sung;Yu, Jae-Eun
    • Journal of Conservation Science
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    • v.29 no.3
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    • pp.287-296
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    • 2013
  • Excavated iron objects are preserved in stable condition through processes of conservation treatment because they are found in the form of various corrosion products. However, the conservation treatment leads to re-corrosion over time and accordingly, iron objects can be severely damaged, and therefore fundamental measures need to be prepared to control it. In this study, the types and characteristics of corrosion products were scientifically analyzed according to the re-corrosion of iron artifacts. In addition, the stability of the corrosion products was evaluated by exposing the standard samples under the re-corrosion environment. Re-corrosion proceeded with weeping in reddish brown on the cracks of iron artifacts. Weeping was detected akagan$\acute{e}$ite had a low hydrogen ion concentration and high chloride ion. The selection of standard sample goethite, lepidocrocite, hematite, and magnetite, were evaluated corrosive by weeping. After the samples were immersed in HCl(pH 1), $H_2SO_4$(pH 1), $H_2O$(pH 6) solution, they had been maintained for 180 days in relative humidity of 20%, 50%, 80% to investiage the changes of chemical components. As a result of analysis, the changes of chemical components were not showed in goethite, lepidocrocite, and hematite. But magnetite was changed to lepidocrocite in solution including chloride ion($Cl^-$) and to goethite and lepidocrocite solution including sulfuric acid($SO{_4}^{2-}$). Results of the study, in the case of magnetite known as s stable corrosion compound, it was identified the corrosion of magnetite occurs by corrosive ions, which means weeping generated in the iron artifacts can corrode magnetite as well as base metal.

Conservation State of Mural Paintings of Royal Tombs in Neungsan-ri, Korea (능산리고분군 동하총 벽화 보존상태 진단)

  • Lee, Sang Ok;Bae, Go Woon;Namgung, Hun;Nam, Do Hyeon;Choi, Yoon Gwan;Chung, Kwang Yong
    • Journal of Conservation Science
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    • v.34 no.5
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    • pp.333-343
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    • 2018
  • This study was conducted to evaluate the conservation environment by monitoring temperature and humidity for two years and mapping the remaining pigments of mural paintings to diagnose the conservation state of mural paintings of Royal Tombs in Neungsan-ri. We evaluated the characteristics of condensation in the tomb. Compared with the results of a 2008 survey, we conducted state change of mural paintings in the tomb. The temperature in the main room, which has an annual average soil temperature distribution at 5 m depth in Korea, is maintained at $13{\sim}18^{\circ}C$. The temperature range of the main room was between less than $0.1^{\circ}C$ to $0.5^{\circ}C$, and the diurnal variation of temperature between summer (June to September) and winter (December to January) is the greatest. Condensation is more concentrated in the summer because the outdoor air was typically at higher temperatures than the main room inflows in the tomb. Mapping the remaining pigment composition and particle distribution of mural paintings showed that it was in the range of 36.72~39.53% of the wall area. The pigment range was confirmed to be the same as it was in 2008, through ultraviolet fluorescence reaction and infrared ray investigation. Therefore, the underground environment that receives dew condensation in the summer has been stable since 2008. However, continuous monitoring is needed because the deterioration of mural painting proceeds considerably after excavation and only a small percentage of the pigments survive.

Study on the Manufacturing techniques & Conservation of Iron Pot from Cheonmachong Ancient Tomb (천마총 출토 철부(鐵釜)의 제작기법 및 보존처리)

  • Lee, Seung Ryul;Shin, Yong Bi;Jung, Won Seob
    • Journal of Conservation Science
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    • v.30 no.3
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    • pp.263-275
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    • 2014
  • It's shown how to proceed the study on Manufacturing techniques & Conservation to the Iron Pot from Cheonmachong Ancient Tomb(the 155th Tomb in Hwangnam-dong). In order to investigate manufacturing techniques of the Iron Pot, some parts of the relic were gathered. After mounting, polishing and etching on the relic, analyzing the metal microstructure was conducted. Also it's conducted a SEM-EDS analysis on the nonmetallic inclusion. White iron structure was observed in the metallurgical structure inspection, SEM-EDS analysis. It seems to be dried slowly at room temperature after casting, doesn't look as particular heat treatment to improve brittleness. It is estimated that it's as the handle seam side were verified about 3cm inch wide, 1.5 thick in center of body, so 2 separate half-completed products was cast with width-type mould. The manufacturing techniques Using white cast iron structure, width-type mould are observable to the Iron Pot excavated from Sikrichong Ancient Tomb & Hwangnamdaechong grand Ancient Tomb around those were constructed the same time. It's able to recognize that it's almost identical manufacturing techniques at that time. Conservation is generically following those are survey of pretreatment, foreign material removal, stabilization, restoration and color matching in the order. cleaning & drying were added to the process as occasion demands. The strengthening treatment were difficult with artifact's volume, low concentration Paraloid NAD-10 solution was spread two or three times with a brush, surface hardening also came up with 15wt% Paraloid NAD-10 solution after the conservation was complete. There were connection & restoration for the restoration to the damage after modeling forms that it's similar to damaged parts by using the Fiber Reinforced Plastic resins(POLYCOAT FH-245, mold laminated type). Throughout this research, capitalizing on accumulations of measurements about the production technique of Iron Pot in the time of the fifth and 6th centuries is no less important than the Iron artifact's conservation for a better study in the future.

Study on Iron-making and Manufacturing Technology of Iron Swords with Ring Pommel Excavated in Ipbuk-dong, Suwon (수원 입북동 출토 철제환두도의 제철과 제작기술 연구)

  • Kim, Soo-Ki
    • Journal of Conservation Science
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    • v.32 no.4
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    • pp.579-588
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    • 2016
  • This study analyzed nonmetallic inclusions in iron swords with a ring pommel excavated in the Ipbuk-dong, Suwon. Scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS) was used to estimate the iron-making temperature, and we compared the oxide with $SiO_2$ to investigate the heat-treatment technology in the production of iron swords with a ring pommel by investigating the artificial insertion of a slag former and the metallurgical structure. From the wustite observed in most of the specimens, it is judged that these swords were produced by heating and forging iron smelted at a low temperature using the solid reduction method. In addition, judging from the partial presence of $P_2O_5$, it is assumed that they were smelted directly with natural ore, not calcined. From the ratios of $CaO/SiO_2$ and $TiO_2/SiO_2$, it is judged that the raw material for iron-making was iron ore and that a calcareous slag former was not artificially inserted. The structure of the blade part on the front end was pure iron. From the high carbon content of the blade part on the ring pommel and the formation of a martensitic structure and pearlite colony, it is judged that they were tempered after carburizing and that the back, handle part, and ring pommel were unintentionally carburized. Judging from the structure of these specimens, it was noted that they were produced by applying artificial partial heat-treatment technology. This study attempted to present a more scientific analysis by using the method of interpretation through component analysis of nonmetallic inclusions appearing in one relic by the ratio of the oxide divided by $SiO_2$. It is judged that reinterpreting the arguments by the results of the existing analysis and research in this way can obtain different interpretations.

Interpretation of Limestone Provenance, Materials and Making Characteristics for Lime-Soil Mixture on Tomb Barrier of the Yesan Mokri Site in Joseon Dynasty (조선시대 예산 목리유적 회격묘의 재질 및 제작특성과 석회의 산지 해석)

  • Lee, Chan Hee;Cho, Ji Hyun;Kim, Jiyoung
    • Journal of Conservation Science
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    • v.32 no.4
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    • pp.471-490
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    • 2016
  • This study investigated provenance of raw materials and making technique of lime-based materials used in the tomb barriers of the Yesan Mokri tombs from Joseon dynasty on the basis of analysis to material characteristics and physical properties. In the barrier materials, dry density and porosity are the highest value ($1.82g/cm^3$) and the lowest value (25.20%) in the south wall of No. 1 tomb, respectively. Dry density and porosity are inversely proportional in all barrier materials, but unconfined compressive strength, which is the highest value of $182.36kg/cm^2$ in the No. 2 tomb, does not show an interrelation with porosity and density. Mineral components in the lime-soil mixtures of the tomb barrier are mainly quartz, feldspar, mica and calcite about 200 to $600{\mu}m$ size with yellowish brown matrix. Hydrotalcite and portlandite are detected in the lime mixture, and kaolinite in the soils. The lime materials of the tomb barrier occurred in large quantities weight loss and variable endothermic peaks caused by decarbonization reaction of $CaCO_3$ in the range from 600 to $800^{\circ}C$ in thermal analysis. Making temperature of lime for the tomb barrier is presumed approximately about $800^{\circ}C$ based on the occurrences, compositions and thermal analysis. The tomb barriers are revealed to very wide composition ranges of major elements and loss-on-ignition (22.5 to 33.6 wt.%) owing to mixture of the three materials (lime, sand and clay). It is interpreted that low quality construction technique was applied as the limes are very heterogeneous mixture with aggregates, and curing of the lime was poorly processed in the tomb barriers. Possible limestone sources are distributed in many areas around the Mokri site where limestone conformation and quarries for commercial production are found within Yesan and Hongseong areas. Therefore, we estimated that raw materials were possibly supplied from the local mines near the Mokri site.

A Combat Effectiveness Evaluation Algorithm Considering Technical and Human Factors in C4I System (NCW 환경에서 C4I 체계 전투력 상승효과 평가 알고리즘 : 기술 및 인적 요소 고려)

  • Jung, Whan-Sik;Park, Gun-Woo;Lee, Jae-Yeong;Lee, Sang-Hoon
    • Journal of Intelligence and Information Systems
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    • v.16 no.2
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    • pp.55-72
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    • 2010
  • Recently, the battlefield environment has changed from platform-centric warfare(PCW) which focuses on maneuvering forces into network-centric warfare(NCW) which is based on the connectivity of each asset through the warfare information system as information technology increases. In particular, C4I(Command, Control, Communication, Computer and Intelligence) system can be an important factor in achieving NCW. It is generally used to provide direction across distributed forces and status feedback from thoseforces. It can provide the important information, more quickly and in the correct format to the friendly units. And it can achieve the information superiority through SA(Situational Awareness). Most of the advanced countries have been developed and already applied these systems in military operations. Therefore, ROK forces also have been developing C4I systems such as KJCCS(Korea Joint Command Control System). And, ours are increasing the budgets in the establishment of warfare information systems. However, it is difficult to evaluate the C4I effectiveness properly by deficiency of methods. We need to develop a new combat effectiveness evaluation method that is suitable for NCW. Existing evaluation methods lay disproportionate emphasis on technical factors with leaving something to be desired in human factors. Therefore, it is necessary to consider technical and human factors to evaluate combat effectiveness. In this study, we proposed a new Combat Effectiveness evaluation algorithm called E-TechMan(A Combat Effectiveness Evaluation Algorithm Considering Technical and Human Factors in C4I System). This algorithm uses the rule of Newton's second law($F=(m{\Delta}{\upsilon})/{\Delta}t{\Rightarrow}\frac{V{\upsilon}I}{T}{\times}C$). Five factors considered in combat effectiveness evaluation are network power(M), movement velocity(v), information accuracy(I), command and control time(T) and collaboration level(C). Previous researches did not consider the value of the node and arc in evaluating the network power after the C4I system has been established. In addition, collaboration level which could be a major factor in combat effectiveness was not considered. E-TechMan algorithm is applied to JFOS-K(Joint Fire Operating System-Korea) system that can connect KJCCS of Korea armed forces with JADOCS(Joint Automated Deep Operations Coordination System) of U.S. armed forces and achieve sensor to shooter system in real time in JCS(Joint Chiefs of Staff) level. We compared the result of evaluation of Combat Effectiveness by E-TechMan with those by other algorithms(e.g., C2 Theory, Newton's second Law). We can evaluate combat effectiveness more effectively and substantially by E-TechMan algorithm. This study is meaningful because we improved the description level of reality in calculation of combat effectiveness in C4I system. Part 2 will describe the changes of war paradigm and the previous combat effectiveness evaluation methods such as C2 theory while Part 3 will explain E-TechMan algorithm specifically. Part 4 will present the application to JFOS-K and analyze the result with other algorithms. Part 5 is the conclusions provided in the final part.

A Study on the Characteristic and Manufacture Technique for the Gold wire of Phoenix-Shaped Glass Ewer by National Treasure No. 193 (국보 제193호 봉수형유리병 금사의 특성과 제작기법 연구)

  • Hwang, Hyun Sung;Yun, Eun Young
    • Journal of Conservation Science
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    • v.31 no.1
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    • pp.21-27
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    • 2015
  • The Phoenix-shaped Glass Ewer, which is No. 193 National Treasure, was seriously damaged by a unique form of green glass pieces when excavated among a number of burial accessories of Hwangnamdaechong known to have been formed in the 5th century. While it has long been exhibited at the National Museum of Korea since its treatment for conservation treatment at conservation science laboratory in 1984, the existing adhesive materials seriously deteriorated for the 30 years, and the condition was quite unstable. The epoxy resin used as a restorative materials turned yellowing due to the light and heat so much that it was no longer able to exhibit it in a stable and effective manner. As a result, a re-treatment for conservation was conducted lately. This study focuses on the three pieces of Gold wires used to carefully wrap up the handle of the Phoenix-shaped Glass Ewer broken into three pieces, which has not been studied so far. As for the analysis method for Gold wires, SEM-EDS and Stereo Microscope were used for nondestructive analysis. First of all, the result of the SEM-EDS analysis shows that the composition was Au 91.9 wt.%-Au 92.8 w.t% and Ag 5.9 wt.%-Ag 6.5 wt.%, which indicates that it was an alloy made of Au and Ag. The production technique of Gold wires was also observed by means of optical microscopes. In general, Gold wires were manufactured by a drawing process in which a lump of gold was beaten or pulled out of a hole or by a process of twisting a gold plate. However, Gold wires separated from the handle of the Phoenix-shaped Glass Ewer did not involve any trace of twisting on the surface. Rather, fine vertical stripes were observed with the sections filled up. Hence, it is thought that this Ewer went through a drawing process and then was mended. As a result, no certain relation with the golden mending material used for the Phoenix-shaped Glass Ewer was verified. The findings above indicate that most of the existing researches on Gold wires recognized them, not as separate remains, but merely as a component of other golden remains. Thus, there has been little systematic study on the manufacturing techniques of Gold wires. The future study on Gold wires may verify the correlation between the Gold wires used to fix the handle of the Phoenix-shaped Glass Ewer, which is examined in this study, with that of golden remains in the Silla era.

Study on the Development and Properties of Ceramics Restoration Purpose Urethane resin with Excellent Reversibility (가역성이 우수한 도자기 복원용 Urethane resin의 개발 및 물성에 대한 연구)

  • Oh, Seung Jun;Park, Gi Jung;Wi, Koang Chul
    • Journal of Conservation Science
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    • v.31 no.1
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    • pp.37-46
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    • 2015
  • In the case of adhesives & restoration agents currently being used for the preservation treatment of ceramics and earthenware, epoxy type, cellulose type and cellulose type are mainly being used. However, they are showing various problems such as re-detachment from severe contraction, color change from yellowing, work inconvenience of staining on tools and hand during usage and irreversibility. For the purpose of solving the issues of yellowing and irreversibility of epoxy resin being used to restore ceramics, urethane synthetic resin with low yellowing excellent reversibility has been developed in this study. The adhesive strength of urethane resin that has been developed has excellent properties with 2.07MPa for undiluted solution, which is 1.5 times higher than that of existing material EPO-$TEK301^{(R)}$ 1.21MPa. The result of workability measurement showed that the wear rate of urethane resin (in Talc 50wt%) was 1.09%, which was somewhat higher than that of existing material Quick $Wood^{(R)}$ (1.02%). In addition, its wear rate is two times higher than that of $EPO-TEK301^{(R)}$ (0.41%) and $L30^{(R)}$ (0.39%), thereby showing an advantage in its forming process compared to existing materials. As for the advantage of urethane resin of reversibility experiment, 12 hours after acetone, ethyl alcohol deposition, urethane resin and filler talc were dissolved 100% while showing powdering phenomenon. Compared to 0% reversibility of existing epoxy resin, it has much superior reversibility. The result of UV rays experiment to evaluate its durability showed that ${\Delta}E^*ab$ color change value based on undiluted solution of urethane resin was 2.76 before & after UV rays exposure, which was a decrease by about 7-20 times compared to that of existing resin, thereby minimizing the issue of heterogeneity.

Base Study Related with Development of Natural Bio-Adhesives Using Seaweeds (해초류를 이용한 천연 바이오 접착제 개발 기반 연구)

  • Han, Won-Sik;Oh, Seung-Jun;kim, Young-Mi;Lee, You-Jin;Kim, Ye-Jin;Park, Min-Seon;Wi, Koang-Chul
    • Journal of Conservation Science
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    • v.34 no.6
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    • pp.595-604
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    • 2018
  • In this study, in a bid to develop natural bioadhesives for paper craft, the hanji industry, and preserving cultural assets, complex polysaccharides were extracted from brown and red algae and used as an ingredient in adhesives. Brown algae include sea trumpet, kelp, sea oak, and sea mustard, whereas red algae include Pachymeniopsis elliptica agar-agar weed, Gloiopeltis tenax, and hunori. The polysaccharides were extracted after transforming them from non-aqueous Ca complexes contained in each of the brown and red algae into water-soluble polysaccharides containing alkali metals with a solubility level of 1. and extracted Subsequently, only the polysaccharides were extracted using alcohol precipitation. The adhesion tensile strengths of kelp, a brown algae, and Pachymeniopsis elliptica, a red algae, were 21.58 and 32.99 kgf, respectively. They thus demonstrated better adhesion than that of solid glue products such as water plants (18.45 kgf) and glue sticks (20.45 kgf). The extraction yield of these polysaccharides is supposed to be determined according to their extracted environments; however, no difference in adhesion strength was seen. Further, it was found that the shapes of polysaccharides were determined by their growing environment instead of extraction environment. Use of multi-step alcohol precipitation method during extraction enabled the removal of the constituents except protein and other polysaccharides, thereby demonstrating a stable outcome without cultivation of mold. Furthermore, there was no occurrence of mold even after production of the adhesives by the simple solution method, which demonstrates the adhesive's potential as an environment-friendly adhesive material.