• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.1
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• pp.21-34
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• 2023

This study identified the materials and construction methods of 'Old Wall' in 13 villages which were designated as National Registered Cultural Heritage at the time of designation and examined the their structural changes based on field survey. The results are as follows: First, the 'Old Wall' consisted of 10 Soil-Stone Wall and 5 Stone Wall. At the time of designation, Stone Wall, which was built irregularly by dry-construction of natural stones, is similar in shape, but Soil-Stone Wall showed difference by the construction method of making used stones, joints, and faces. Second, the study extracted the changes of 'Old Wall' by repair and examined the changes of construction methods as well as the substitution and addition of materials of structure. The wall-roof was built with cement roof-tile and asbestos slate which have the advantage improve durability and cost-effectiveness. In addition, tile-mouth soil was added to korean traditional roof-tile to prevent rainwater from flowing in. Besides, to improve constructional convenience, the natural stone of the wall-body was replaced with blast stone, float stone and cut stone. Cement block, cement brick and cement mortar were frequently used to repair as well. As Soil-Stone Wall was transformed from irregular pattern-construction to comb pattern-construction and wet-construction was changed to dry-construction, it caused landscape and structural problems. Also, the layer of cement mortar applied to wall-foundation blocked the flow of rainwater that was induced by dry-construction of natural stones. Third, the study regarded that the problem with the repair of 'Old Wall' may occur as it is located in living space, because the owner of the wall could repair for the minor damages without technical knowledge. In addition, it is difficult for repair companies in charge of maintenance of Cultural Heritage to supply local materials, and it is differential construction specifications are not applied.

• Archives of Plastic Surgery
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• v.40 no.3
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• pp.181-186
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• 2013

Background Partial or complete necrosis of a skin flap is a common problem. Polydeoxyribonucleotide (PDRN) can be extracted from trout sperm and used as a tissue repair agent. The aim of this study was to investigate whether PDRN could improve the survival of random pattern skin flaps in rats. Methods Twenty-two male Sprague-Dawley rats were randomly divided into two groups: the PDRN treatment group (n=11) and the control group (n=11). Caudally pedicled random pattern skin flaps were elevated on their dorsal skin and resutured. The treatment group received daily intraperitoneal administration of PDRN (8 mg/kg/day), and the control group received fluid vehicle (NaCl 0.9%, 8 mg/kg/day) from day 0 to day 6. On day 7, the flap survival was evaluated and the harvested tissue surrounding the demarcation line of the necrotic area was stained with H&E, anti-rat vascular endothelial cell growth factor (VEGF) antibody, and PECAM-1/CD31 antibody. Results The average necrotic area of the flap in the PDRN group was significantly smaller when compared with that of the control group. Histologic and immunohistochemical evaluation showed that granulation thickness score and VEGF-positive staining cells were marked higher in the PDRN group than in the control group. PECAM-1/CD31-positive microvascular densities were significantly higher in the PDRN group when compared with the control group. Conclusions This study confirms that PDRN improves the survival of random pattern skin flaps in rats. These results may represent a new therapeutic approach to enhancing flap viability and achieving faster wound repair.

• Journal of the Mineralogical Society of Korea
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• v.31 no.3
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• pp.149-159
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• 2018

The Gyeongju Bunhwangsa Stone Brick Pagoda, which was built with bricks of andesite, is the oldest brick stone pagoda of Silla period. The damage patterns in the stone pagoda are pollutants such as white crust, black crust, discoloration, soil adsorption, and microorganisms, and repair materials. The damage pattern of structural factors in the Stone Brick Pagoda is a bulging phenomenon. According to the X-ray diffraction analysis, white crust are mainly consist of calcite ($CaCO_3$) and thermonatrite ($Na_2CO_3{\cdot}H_2O$) that evaporite finds in nature. Damage pattern varies depending on location of stone pagoda. The pollutants are first story body of pagoda. The microorganisms are confirmed at base, lion statues, first and second story capstone, and repair materials observed at base. The bulging phenomenon appeared on the first story body of the pagoda. Occupancy rates by damage type were higher in the order of microorganisms, pollutants, repair material, bulging phenomenon, and peeling. The highest percentage of individual damage patterns were black microorganisms (39.3%), followed by lichen (17.9%), discoloration (8.0%), white crust (5.5%), cement mortar (5.1%) and peeling (3.1%).

• IMMUNE NETWORK
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• v.2 no.4
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• pp.208-216
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• 2002

Background: Reactive oxygen and nitrogen are produced by rheumatoid arthritis (RA) synovial tissue and can induce mutations in key genes. Normally, this process is prevented by a DNA mismatch repair (MMR) system that maintains sequence fidelity. Key members of the MMR system include MutS${\alpha}$ (comprised of hMSH2 and hMSH6), which can sense and repair single base mismatches and 8-oxoguanine, and MutS${\beta}$ (comprised of hMSH2 and hMSH3), which repairs longer insertion/deletion loops. Methods: To provide further evidence of DNA damage, we analyzed synovial tissues for microsatellite instability (MSI). MSI was examined by PCR on genomic DNA of paired synovial tissue and peripheral blood cells (PBC) of RA patients using specific primer sequences for 5 key microsatellites. Results: Surprisingly, abundant MSI was observed in RA synovium compared with osteoarthritis (OA) tissue. Western blot analysis of the same tissues for the expression of MMR proteins demonstrated decreased hMSH6 and increased hMSH3 in RA synovium. To evaluate potential mechanisms of MMR regulation in arthritis, fibroblast-like synoviocytes (FLS) were isolated from synovial tissues and incubated with the nitric oxide donor S-nitroso-N-acetylpenicillamine (SNAP). Western blot analysis demonstrated constitutive expression of hMSH2, 3 and 6 in RA and OA FLS. When FLS were cultured with SNAP, the RA synovial pattern of MMR expression was reproduced (high hMSH3, low hMSH6). Conclusion: Therefore, oxidative stress can relax the DNA MMR system in RA by suppressing hMSH6. Decreased hMSH6 can subsequently interfere with repair of single base mutations, which is the type observed in RA. We propose that oxidative stress not only creates DNA adducts that are potentially mutagenic, but also suppresses the mechanisms that limit the DNA damage.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.6
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• pp.191-197
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• 2006

This study is to establish a standardization of injection system by inorganic material for crack repair of tunnel concrete structures. For this various surveys and experiments were carried out as followed. The first we surveyed capability of injection and crack pattern of concrete structures in site. and second we analyzed the relationship between crack width and volume of injection, and decided pressure and volume of injection. Finally we evaluated the relationship between crack width and volume of injection with kind of concrete structures, and between required time for injection and crack width with thickness of structure. From these surveys and experiments, we cleared the relationship between crack patterns and injection technologies such as volume, pressure of injection and required time for injection with kind of structure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.104-107
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• 2002

Direct Metal Manufacturing (DMM) is a new additive process that aims to take die making and metalworking in an entirely new direction. It is the blending of five common technologies : lasers, computer-aided design (CAD), computer-aided manufacturing (CAM), sensors and powder metallurgy. The resulting process creates parts by focusing an industrial laser beam onto a tool-steel work piece or platform to create a molten pool of metal. A small stream of powdered tool-steel metal is then injected into the melt pool to increase the size of the molten pool. By moving the laser beam back and forth, under CNC control, and tracing out a pattern determined by a computerized CAD design, the solid metal part is built line-by-line, one layer at a time. DMM produces improved material properties in less time and at a lower cast than is possible with traditional fabrication.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.122-130
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• 2013

The demand and the supply are increasing sharply in accordance with the growth of the Memory Semiconductor Industry. The Flash Memory above all is being utilized substantially in the Industry of smart phone, the tablet PC and the System on Chip (SoC). The Flash Memory is divided into the NOR-type Flash Memory and the NAND-type Flash Memory. A lot of study such as the Built-In Self Test (BIST), the Built-In Self Repair (BISR) and the Built-In Redundancy Analysis (BIRA), etc. has been progressed in the NOR-type fash Memory, the study for the Built-In Self Test of the NAND-type Flash Memory has not been progressed. At present, the pattern test of the NAND-type Flash Memory is being carried out using the outside test equipment of high price. The NAND-type Flash Memory is being depended on the outside equipment as there is no Built-In Self Test since the erasure of block unit, the reading and writing of page unit are possible in the NAND-type Flash Memory. The Built-In Self Test equipped with 2 kinds of finite state machine based structure is proposed, so as to carry out the pattern test without the outside pattern test equipment from the NAND-type Flash Memory which carried out the test dependant on the outside pattern test equipment of high price.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.122-129
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• 2019

Due to its nature the manufacturing industry faces a cyclical economy, and therefore there is an urgent need for a companion industry to cope with this cyclic pattern in the long run. The sector suitable for meeting this demand is the repair and shipbuilding industry. In order to operate a shipbuilding repair business, a floating dock is indispensable, and most obsolete floating docks were imported from overseas and operated through repair/maintenance. However, there is no precise guideline for floating dock safety, and most models have been in use for at least 30 years without being required to enter classification at the time of operation. In this study, structural strength analysis was carried out using measured thickness information of aged floating docks, and the residual structural strength of floating docks in operation was analyzed. The main results derived from this study can be referred to as guidelines for the review of the structural safety of similar equipment, and it is expected that an optimal solution will be found within a short time using this method for repair/maintenance.

• Clean Technology
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• v.22 no.4
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• pp.232-240
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• 2016

Recently, various research studies have been conducted and many are in progress for the suitable alternative materials for ITO based touch screen panel (TSP) due to limitations in size and flexibility. Various researches from all over the world have been attempted to fabricate the fine electrode less than $5{\mu}m$ for the rapid developing of display technology. Research is also being carried out in metal mesh methods using the existing technologies and alternative materials at commercial level. However, by using the existing technologies certain discrepancies are observed like low transparency and low yield which also results in the distortion of patterns. For repairing the damaged pattern, the conventional laser CVD technique has also been used but there are some challenges observed in CVD technique like achieving a stable fine electrode of $10{\mu}m$ or less and avoiding the formation of satellite drops. To overcome these issues, a new printing process named Electrohydrodynamic (EHD) printing, has been introduced by which $5{\mu}m$ fine patterns can be printed in one step. This EHDA printing technique has been applied to print very fine electrodes of $5{\mu}m$ or less by using conductive inks of various viscosities. This study also presents the optimized process parameters for printing $5{\mu}m$ fine electrode patterns during experiments by controlling the applied voltage and supply flow rate. The $5{\mu}m$ repair electrodes were fabricated for repairing $50{\mu}m$ shorted electrode samples.

• Journal of the Korean Arthroscopy Society
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• v.13 no.2
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• pp.155-160
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• 2009

Purpose: The purpose of this study was to evaluate the pain recovery pattern according to the integrity and to analyze the factors affecting the progress and level of pain postoperatively. Materials and Methods: We examined 153 patients, who were treated with arthroscopic rotator cuff repair. 101 rotator cuff tears were full-thickness tear and 52 were partial tear. The mean follow up duration was 20 months (12~30 months). We evaluated the visual analogue scale, range of motion, ASES (American Shoulder and Elbow Surgeons), and UCLA (University of California at Los Angeles) scores preoperatively and postoperatively. We analyzed the pain recovery pattern between partial and full thickness tear using Student T-test and the factors affecting the progress and level of postoperative pain using multiple regression analysis. Results: The change patterns of visual analogue scale after arthroscpoic repair were similar regardless of the tear integrity. The VAS showed a continuous decreasing pattern, but increased at first 3 weeks postoperatively and at 7 weeks postoperatively, and then, decreased thereafter. The average VAS was ${\leqq}2$ points by postoperative 3 months. The factor affecting the pain score at 3 months was related to the preoperative limitation in forward flexion ($r^2=0.377$, p=0.021). Conclusion: There was no differences of the pain recovery pattern according to the integrity, and the factor affecting the progress of postoperative pain was preoperative angle of forward elevation. So, the appropriate preoperative rehabilitation protocol that can improve motions of the shoulder joint would help to improve the level of postoperative pain and functional recovery.