• Conservation Science in Museum
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• v.11
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• pp.9-16
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• 2010

The National Chuncheon Museum has carried out a conservation process in order to prevent corrosion of the seated iron Śākyamuni Buddha statue from Goreyo Dysnasty for its exhibition. Before the conservation process, the surface of the artifact showed exfoliation and the artifact was damaged from rear to legs so exhibition was impossible. Therefore a process to get rid of pollution and to reinforce and protect the artifact was carried out. Before the reinforcing process, a basic test was carried out using micro crystalline wax type with reference to foreign and domestic experiment results. As a result, as wax(in xylene) 5wt% of Dongnam petrochemical Ltd. showed no efflorescence and little change in surface color and was convenient to use, it was chosen as a reinforcing agent and used to suppress corrosion. For the restoration of damaged parts, an internal support was made and used with an epoxy resin, allowing removable restoration, thus increasing effectiveness for exhibition.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.4
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• pp.91-98
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• 2017

Electrical impedance tomography is a nondestructive imaging technique to reconstruct unknown conductivity distribution based on applied current data and measured voltage data through an array of electrodes attached on the periphery of a domain. In this paper, an inverse method based on truncated singular value decomposition is proposed to solve the inverse problem with the generalized Tikhonov regularization and to reconstruct the conductivity distribution. In order to reduce the inverse computational time, truncated singular value decomposition is applied to the inverse term after the generalized regularization matrix is taken out from the inverse matrix term. Numerical experiments and phantom experiments have been performed to verify the performance of the proposed method.

• Conservation Science in Museum
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• v.10
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• pp.21-27
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• 2009

This bamboo brush stand was made by attaching two bamboo tubes together, each 80mm in diameter. On the bottom is a "∞-shaped"wood board made of Ailanthus altissima. The surfaces are decorated with exquisite and dynamic designs of a dragon and clouds, and a deer and pine trees. Part of this bamboo brush stand was damaged, lost, or worn down, prior to conservation treatment. After conservation and recovery treatment, its original form was restored. Earth powder, chalk, and gluten mixture were used as materials to fill in the missing parts. After the original form was restored, thin silk fabric was attached to the inner surface of the glued part to prevent cracking. Traditional materials and repair techniques were used to allow for reversal of treatment, if necessary, as seen in the surface of the restored part being made antiquated with lacquer varnish.

• Journal of the Korea Society of Computer and Information
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• v.6 no.4
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• pp.104-109
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• 2001

In this paper, we designed a 3D shape measuring system with high speed and high measurement resolution using line-shaped sine stripes of a LCD projector We proposed an effective method to improve measurement efficiency for a 3D shape measuring system by finding the deficient shape information areas and recovering the shape information efficiently. We experimentally confirmed the improvement of measurement efficiency. Deficient shape information areas can be inevitably existed in a acquired image caused by the camera view angle and surface shapes of an object. The measurement efficiency is turned out to be improved by extracting these shadow areas and recovering the shape information efficiently using both a variable rated normalization and a variable sized phase recovering windows.

• Conservation Science in Museum
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• v.16
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• pp.122-137
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• 2015

White porcelain pitcher with an openwork dragon and cloud design across its surface in the collection of the National Museum of Korea (Deoksu 5531) was acquired in 1915. The restoration has been so far completed only for the mouth of the pitcher. This study discusses a new method based on 3D scanning and printing for the restoration of missing parts in the openwork dragon and cloud design. A strength test was performed on six output materials that have been already commercialized for comparison with the strength of materials used for traditional restoration such as epoxy putty (Quick Wood^®) and epoxy (Araldite AY103+HY956^®). This process confirmed that the digital technology-aided making of a restoration model requires less time and efforts than handmade work, all the while producing a more precise model. More importantly, this method being a non-contact method, it reduces risks associated with handmade work. Another advantage of this method is that digital pre-restoration images can be saved and used for future references. Notwithstanding, future research is needed on how to effectively apply digital technology for restoration of ancient objects and how to evaluate and use 3D output as well as on the method of shaping, joining and coloring the 3D output.

• Conservation Science in Museum
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• v.17
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• pp.101-116
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• 2016

Ceramic cultural artifacts restored with gypsum-based materials are prone to decay over time due to gypsum's natural absorption and release of atmospheric moisture, often leading to distortion and peeling of painted layers. This study proposes a new restoration material which utilizes extra hard stone, significantly superior in strength to regular gypsum. In order to enhance its physical properties and make it suitable for restoration of ceramics, extra hard stone is mixed with metakaolin. This mixture far surpasses regular gypsum in compressive strength(119MPa vs. 26MPa) while also maintaining a much lower wear rate(0.88% vs. 2.53%). Furthermore, the water absorption rate(2.9%) of the mixed material is over five times lower than that of regular gypsum(17.2%). When examined using a SEM(Scanning Electron Microscope), this mixture also proved superior to extra hard stone in terms of hardened density. The addition of metakaolin increases the mixture's strength and water resistance over that of extra hard stone and also improves its surface density, making it ideal for the restoration of ceramics. It has already been used to repair ceramic objects in the Museum's collection: Clay basin(sinan 18892), Buncheong ware bottle with incised peony design(jubsu 2034), Buncheong ware bowl with chrysanthemum(jubsu 1730). Results thus far have shown the mixture to be easy to inject and layer as well as harden into an even surface, which allows for smooth application of paint for color matching.

• Journal of Adhesion and Interface
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• v.16 no.4
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• pp.137-145
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• 2015

This study aimed to develop epoxy putty as a multi-purpose connection and restoration material that can be used for material-specific restoration work such as metal, wood, ceramics, earthenware and stone artifacts by replacing synthetic resins currently being used for preservation treatment of cultural assets. Existing synthetic resins have the issue of cutting force resulting from high strength, deflection resulting from long hardening time, contaminating the surface of artifacts through staining on tools or gloves and need for re-treatment resulting from material discoloration. Accordingly, paste type restoration material most widely being used in the field of cultural assets preservation treatment was selected and examined the property to select it as an object of comparison. Based on such process, epoxy putty was developed according to the kind of agent, hardener and filler. For the purpose of solving the issues of existing material and allowing the epoxy putty developed to have similar property, property experiments were conducted by selecting agents and hardeners with different characteristics and conditions. The study findings showed that both kinds are paste type that improved work convenience and deflection issue as a result of their work time of within 5~10 minutes that are about 3~10 times shorter than that of existing material. In regards to wear rate for increasing cutting force, it improved by about 3 times, thereby allowing easy molding. For the purpose of improving the issue of surface contamination that occurs during work process, talc and micro-ballon were added as filler to reduce the issue of stickiness and staining on hand. Furthermore, a multi-purpose restoration material with low shrinkage, low discoloration and high cutting force was developed with excellent coloring, lightweight and cutting force features.

• Journal of Biomedical Engineering Research
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• v.19 no.4
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• pp.333-339
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• 1998

The effect of heat treatment conditions on the properties of tungsten(W) embolization coils has been evaluated. The W embolization coils were fabricated by coiling the primary W coil with a diameter of 30.mm on a alumina rod mandrel with a diameter of 2.92mm. The secondary coils were then heat treated at 475$^{\circ}C$and 600$^{\circ}C$ for various heat treatment time ranging from 5 minutes to 36hours. The pitch distance, diameter and shape retention capability of the W embolization coils were characterized after the heat treatment. The pitch distance of the W embolization coils increased with the heat treatment time. The diameter of W emboliazation coils decreased continuously with heat treatment time. The shape retention capability of the W embolization coils increased with the heat treatment time due to an increase in elasticity by formation of tungsten oxide film on W coil surface during the heat treatment. The heat treatment condition of W embolization Col at 600$^{\circ}C$ for 20 minute was considered desirable based on the optimization of the shape retention capability, pitch distance and secondary coil diameter after heat treatment.

• KSBB Journal
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• v.21 no.3
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• pp.175-180
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• 2006

In this study, it could be found that the microbial movement in soil under electric field mainly occurred by electrophoresis and electroosmosis. The contribution of electrophoresis on the microbial mobility and flux was generally higher than that of electroosmosis. In the electrokinetic(EK) bioremediation of a pentadecane-contaminated soil, the microbial population increased simultaneously at anode and cathode regions of the soil specimen because both electrophoresis and electroosmosis affected on the microbial movement. After initial operation, the microbial population was high in order of anode, middle, and cathode regions due to their negatively-charged surface and oxygen generation at anode. However, the uniform contaminant removal was achieved by the microbial movement with two-directionality.

• Journal of Conservation Science
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• v.35 no.5
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• pp.453-469
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• 2019

The celadon jar with inscription of 'the Fourth Sunhwa Year' is an important chronology that shows the conditions of production of the early celadon due to the inscription on the bottom including its purpose, application, and the producer. This celadon jar has been restored several times in the past. However, concerns over the structural stability, such as the separation and level differences in the joined cracks, have risen because of the aging of the repair materials, which were subjected to various environmental changes over a long time. By examining the conditions of preservation, the major damage was identified as the '入' shaped crack on the front, the 'V' shaped restored part and the crack on its left side, and the 'J' shaped crack on the back side. In the past, the cracks were found to be joined using a refined lacquer containing camphor, drying oil, rosin, etc. mixed with soil powder. The joint line was repainted with the refined lacquer and covered with gold powder. The missing parts were restored with gypsum and colored with acrylic color. After that, the repair materials were aged and emergency treatment was performed at the National Museum of Korea in 1981. At that time, Cemedine C or Cemedine C mixed with microballoons was used for reinforcing the cracks. Conservation treatment focused on removing the past repair materials and reinforcing the physically fragile parts by joining and restoring them based on the examination of the preservation condition. in addition, the area around the restored part was colored for future exhibition.