• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.931-935
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• 2012

In this study, we fabricate and investigate low-temperature solid oxide fuel cells with a ceramic substrate/porous metal/ceramic/porous metal structure. To realize low-temperature operation in solid oxide fuel cells, the membrane should be fabricated to have a thickness of the order of a few hundreds nanometers to minimize IR loss. Yttrium-doped barium zirconate (BYZ), a proton conductor, was used as the electrolyte. We deposited a 350-nm-thick Pt (anode) layer on a porous substrate by sputter deposition. We also deposited a 1-${\mu}m$-thick BYZ layer on the Pt anode using pulsed laser deposition (PLD). Finally, we deposited a 200-nm-thick Pt (cathode) layer on the BYZ electrolyte by sputter deposition. The open circuit voltage (OCV) is 0.806 V, and the maximum power density is 11.9 mW/$cm^2$ at $350^{\circ}C$. Even though a fully dense electrolyte is deposited via PLD, a cross-sectional transmission electron microscopy (TEM) image reveals many voids and defects.

• Journal of the Korean Society of Costume
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• v.62 no.3
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• pp.137-151
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• 2012

In 1966, $Seokgatap$ pagoda in $Bulguksa$ temple was damaged by the tomb robbers and was dismantled to fix the damage. In the process, many offerings to Buddha and containers for Sarira(the cremated remains) were found in $Sarigong$(specially designated space for the Sarira casket) inside the second floor of the pagoda. Many fabrics like $Geum$, $Neung$(twill), $Rha$(complex gauze), silk tabby and linen were also excavated. In this study, $Geum$ fabric from the $Seokgatap$ was closely examined. $Geum$ of $seokgatap$ is weft-faced compound weave according to the analysis of its weaving pattern which was wrongly presumed as warp-faced compound weave for some time. Technical analysis of $Geum$: Main: silk, Binding: silk, Proportion: 1 main warp to 1 binding warp, Count: 15 main warps and 15 binding warps per centimeter, Weft: polychrome silk without apparent twist, Colors: yellow, mustard yellow, deep blue, green and purple, Weave: weft-faced compound twill, 1/2 S. $Geum$ of $Seokgatap$ was made in the $8^{th}$ century, since it was weaved in weft-faced compound weave twill which was popular in the $8-9^{th}$ century. And also, the arrangement of the colors was done in the same way of gradation $Geum$ silk which was popular in the $7-8^{th}$ C in China and Japan. Third, we restored the pattern of $Geum$ of the Unified Shilla Dynasty for the first time. It was very difficult to figure out the shape and the size of pattern since the fabric was partially lost and ruined. We tried to draw the diagram of structure with the cross point of the warp and the weft to restore the pattern. By doing so, we could identify two kinds of small flower pattern, palmette and the pattern of repeating vines. Fourth, we could infer that the $Geum$ of $Seokgatap$ was used for $geumdae$(a pouch made of $geum$) by analyzing all the documents and the characteristics of the fabric.

• Composites Research
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• v.31 no.5
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• pp.186-191
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• 2018

Condition and properties of composites with different chemical structure of epoxy matrix were observed after saline solution treatment. Epoxy was used as matrix and the flexibility was controlled by using 2 typed-epoxies and 3 types hardeners (amine, acid anhydride and amide). Saline water treatment was conducted with 6 wt% NaCl solution at $60^{\circ}C$ for 0, 15, and 30 days. Cross section was observed and interfacial and mechanical and properties was evaluated. Amine type exhibited the highest crosslinking density and mechanical and interfacial properties whereas water absorbance was lowest. It is because that the water molecules can be hardly penetrate into the epoxy matrix or the interface between epoxy and glass fiber and it leads to saline water resistance of composites.

• Archives of Plastic Surgery
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• v.32 no.3
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• pp.335-342
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• 2005

This study was undertaken to investigate possibility of the allogenic type I collagen inducing osteoinduction or osteoconduction at critical sized bone defect in the rabbit. Twenty Newzealand white rabbit, weighted from 2.8 kg to 3.5 kg, were used in this study. The skull was exposed and two bony defects were created with diameter of 10 mm. Group I(n=10), the bony defects was grafted from the other side bone. Group II(n=10), the bony defects was grafted by the allogenic type I collagen with bone morphogenic protein(BMP). Group III(n=10), the bony defects was grafted by the allogenic type I collagen only. Group IV(n=10), the bony defects was lefted with no grafts. The grafted bones and allogenic type I collagen were investigated with radiologic densitometry, histologic analysis and immunohistochemistry after 12 weeks. No major difference was observed in the gross finding between Group I, II, III, but dura mater was exposed in bony defect,the Group IV. The radiologic study demonstrated more bony opacity in the Group I, but the other groups did not demonstrate a significant difference. In the histologic study, grafted bone edge was completely consolidated with original bone in group I and new bone ingrew into the grafted allogenic type I collagen(group II, III),but there is no bone regeneration from the original bony edge in the group IV. The percent of the new bone formation by cross-sectional area was considered statistically significant at a p value of less than 0.05(p<0.05). In the immunohistochemistry study about BMP antibodies, the group IV demonstrated osteogenic activity in front of advancing original bone edge, in which the osteoblast stained strongly for BMP antibodies, but other group does not demonstrated any osteoblastic expression. There was no immunologic rejection. In conclusion, this results do not demonstrate that the allogenic type I collagen is useful for bone substitute, but the characters of the collagen, such as pliability, easy-handling, sponge-like structure, are useful in interpositional bone graft substitutes. The further evaluation of long term results about the resorption, immunologic tissue reaction, response of applied tissue growth factor to the allogenic collagen is needed.

• The Plant Pathology Journal
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• v.36 no.4
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• pp.305-313
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• 2020

Host shifting and host expansion of fungal plant pathogens increases the rate of emergence of new pathogens and the incidence of disease in various crops, which threaten global food security. Magnaporthe species cause serious disease in rice, namely rice blast disease, as well as in many alternative hosts, including wheat, barley, and millet. A severe outbreak of wheat blast due to Magnaporthe oryzae occurred recently in Bangladesh, after the fungus was introduced from South America, causing great loss of yield. This outbreak of wheat blast is of growing concern, because it might spread to adjacent wheat-producing areas. Therefore, it is important to understand the host range and population structure of M. oryzae and related species for determining the evolutionary relationships among Magnaporthe species and for managing blast disease in the field. Here, we collected isolates of M. oryzae and related species from various Poaceae species, including crops and weeds surrounding rice fields, in Korea and determined their phylogenetic relationships and host species specificity. Internal transcribed spacer-mediated phylogenetic analysis revealed that M. oryzae and related species are classified into four groups primarily including isolates from rice, crabgrass, millet and tall fescue. Based on pathogenicity assays, M. oryzae and related species can infect different Poaceae hosts and move among hosts, suggesting the potential for host shifting and host expansion in nature. These results provide important information on the diversification of M. oryzae and related species with a broad range of Poaceae as hosts in crop fields.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.4
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• pp.325-334
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• 2006

Understanding the airflow characteristics within the canopy structure installed between closely adjacent tunnels either for light adaptation or for protection from snow hazards is required for the normal ventilation as well as safety system design. Grade, horizontal alignment, cross-sectional area and shape are known to substantially influence the fire smoke behavior and their influences raise great concern for the safety design. This paper aims at studying the effects of tunnel geometrical characteristics and canopy installation on the ventilation and fire propagation through CFD analysis. In the case of 145m long canopy, 50% opening ratio is preferred with respect to the airflow pattern and ventilation efficiency. When a 20MW fire occurs in a 1.8km-long tunnel and four 1250mm reversible jet fans are instantly turned on, smoke concentration at 40m downstream of the fire decrease 13% for the upgrade tunnel with 2% gradient and increases 20% for -2% gradient, compared to the standard horizontal tunnel. Backlayering is observed within 45m-long segment toward the entrance in 2% down-graded tunnel. In a rectangular tunnel, there is no significant difference of smoke concentration as well as velocity profile from the standard crown tunnel. Three-laned tunnel shows lower level of both profiles and backlayering is detected up to 50m upstream of the fire, while the risky situation rapidly disappears thereafter.

• Journal of architectural history
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• v.20 no.3
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• pp.7-22
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• 2011

With the accumulations of outcomes from archaeological excavations of mountain fortress of three kingdoms period, there have been studies about time-periodic territory range of mountain fortress, difference in the way(method) of construction, defence system and so on from various points of view. This is an empirical study on the construction method of the valley part of stone fortress. First of all, it is required to secure large quantity of fresh water for those who lived at mountain fortress. Especially when builders of fortress construct a fortification at the valley part of stone fortress, in advance they must sufficiently consider several options including the establishment of sustainable water resources. First, when it comes to build a fortification on a ridge[or a slope] of a mountain, you have only to consider a vertical stress. However, when it comes to build a fortification at the valley part of a mountain, You must have more sufficient preparations for the constructing process. Because there are not only a vertical stress but also a horizontal pressure simultaneously. Second, a fortification of mountain fortress built by using unit building stone is a structure of masonry construction like brick construction, and the valley part of it is where the construction of the fortification begins. Third, when it comes to build a fortification at the valley part of a mountain, it seems that they use a temporary method such as coffer dam in oder to prevent the collapse of the fortification due to heavy rain. Furthermore, in response to a horizontal pressure a fortification is built by the way of its plane make an arch, or by piling up the soil with the plate method(類似版築) and earthen wall harder method(敷葉) they increase cross-sectional area of the fortification and its cutoff capacity. In front direction they put the reservoir facility for the fear that the hydraulic pressure and earth pressure are directly transmitted to the fortification. The process of constructing the fortification at the valley part of a mountain is done in the same oder as follows; leveling of ground(整地) ${\Rightarrow}$ construction of coffer dam ${\Rightarrow}$ construction of the fortification between the both banks of the valley ${\Rightarrow}$ construction of the fortification at bottom part of spill way(餘水路) between the both banks of the valley ${\Rightarrow}$ construction of spill way(餘水路) & reservoir facility ${\Rightarrow}$ construction of the fortification at upper part of spill way between the both banks of the valley. Coffer dam facility seems to be not only the protection device on occasion of flood but also an important criterion to measure the proper height of spill way or tailrace(放水路). This study has a meaningful significance in that it empirically examines the method of reduction of the horizontal pressure which the fortification at the valley part of a mountain takes, the date the construction was done, and wether the changes in climate such as heavy rainfall influence the process of construction.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.135-135
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• 2017

The Gramene database (http://www.gramene.org) is a powerful online resource for agricultural researchers, plant breeders and educators that provides easy access to reference data, visualizations and analytical tools for conducting cross-species comparisons. Learn the benefits of using Gramene to enrich your lectures, accelerate your research goals, and respond to your organismal community needs. Gramene's genomes portal hosts browsers for 44 complete reference genomes, including crops and model organisms, each displaying functional annotations, gene-trees with orthologous and paralogous gene classification, and whole-genome alignments. SNP and structural diversity data, available for 11 species, are displayed in the context of gene annotation, protein domains and functional consequences on transcript structure (e.g., missense variant). Browsers from multiple species can be viewed simultaneously with links to community-driven organismal databases. Thus, while hosting the underlying data for comparative studies, the portal also provides unified access to diverse plant community resources, and the ability for communities to upload and display private data sets in multiple standard formats. Our BioMart data mining interface enable complex queries and bulk download of sequence, annotation, homology and variation data. Gramene's pathway portal, the Plant Reactome, hosts over 240 pathways curated in rice and inferred in 66 additional plant species by orthology projection. Users may compare pathways across species, query and visualize curated expression data from EMBL-EBI's Expression Atlas in the context of pathways, analyze genome-scale expression data, and conduct pathway enrichment analysis. Our integrated search database and modern user interface leverage these diverse annotations to facilitate finding genes through selecting auto-suggested filters with interactive views of the results.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.133-133
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• 2017

Lodging is one of the important constraints in rice production. The lodging destroys the canopy structure, and sharply reduces the capacity of photosynthetic rate and dry matter production. In cereal crops, stem lodging can be classified into two types: stem breaking type and stem bending type. To improve stem lodging resistance, it is important to reveal strong culm traits of superior lodging resistant varieties. There are large varietal differences in parameters associated with the bending moment at breaking (M) and flexural rigidity (FR). The indica variety Takanari possesses large M due to its large section modulus (SM) despite of its small bending stress (BS), while Takanari also has large FR due to its large secondary moment of inertia (SMI) and Young's modulus (YM). To identify quantitative trait loci (QTLs) and the corresponding genes associated with the parameters for M ($=SM{\times}BS$) and FR ($=SM{\times}YM$) should enable to develop lodging resistant varieties, efficiently. In order to identify QTLs for cell wall materials such as cellulose, hemicellulose and lignin associated with BS and YM, a set of Chromosome Segment of Substitution Lines (CSSLs) consisted of 37 lines with chromosome segments of Koshihikari in the genetic background of Takanari were used. Takanari had large M and small BS as compared with Koshihikari. The QTLs for BS were estimated on chromosomes 3, 5, 6, 8, 9, 10, 11 and 12. Koshihikari alleles increased BS in these QTLs. Takanari had a large FR due to its large SMI and YM as compared with Koshihikari. The YM was increased by substitution of the Koshihikari chromosomal segments on chromosomes 2, 10 and 11. Other QTLs estimated on chromosomes 7 and 12 that Koshihikari alleles contributed to the decrease of YM. For lignin, only one major QTL for lignin density was detected on chromosome 11. Hollocellulose densities were increased by the substitution of Koshihikari segments on chromosomes 5 and 11. On the other hand, these were decreased on chromosomes 1 and 3 by substitution of Koshihikari segments. QTLs for cellulose density were estimated on chromosomes 1, 3 and 5 by substitution of Koshihikari segments. For hemicellulose, QTL on chromosome 3 showed that hemicellulose density decreased by the substitution of Koshihikari segment. However, hemicellulose densities on chromosomes 5, 8 and 11 showed the opposite effects. The QTLs for hemicellulose, cellulose, and hollocelulose densities identified on chromosome 5 overlapped with that for bending stress, indicating the positive effect of Koshihikari segment on increasing bending stress. These results suggest that some QTLs for the densities of cell wall materials contribute to increasing bending stress and Young's modulus, and could be utilized to improve the lodging resistance for both types of breaking and bending in rice varieties.

• Economic and Environmental Geology
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• v.39 no.4 s.179
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• pp.441-450
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• 2006

The on-land seismic survey in Korea was begun in mid-1960s. Kim et al.(1967) of Korea Geological Survey reported on the result of gravity and seismic reflection surveys conducted in the Pohang area for the period of 1963-64 to assess its possibility of oil entrapment. Hyun and Kim (1966) carried out a refraction survey on the tunnel wall. Since then, the KGS geophysicists had conducted seismic surveys on Kyungsang sedimentary basin as a main project for several years. In 1970s, on-land seismic surveys had been conducted for various purposes such as site investigation for the nuclear power plants and industrial complex, exploration for ground water, mineral resources and underground tunnel. The first reflection survey with CMP acquisition was attempted in 1978 by using a digital recording system. But most of on-land seismic surveys had employed the refraction method until 1980s. In 1990s, high resolution reflection and various borehole seismic surveys such as tomography, uphole, downhole, cross-hole methods have been attempted by universities and engineering companies. The applications of on-land seismic surveys have been enlarged for both academic and industrial purposes such as investigation of geologic structure of the fault and tidal flat area, construction of highway, railroad and dam, geothermal energy and mineral resource exploration, environmental assessment for waste disposal sites and archaeological investigations. In 2002, the first crustal seismic survey was carried out on the profile of 294km length across the whole peninsular. It is expected that the advanced technology and experience acquired through offshore seismic surveys, which have been conducted in continental shelf of Korea and foreign oil fields, will stimulate the more active on-land seismic explorations.