• Korean Journal of Heritage: History & Science
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• v.38
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• pp.179-222
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• 2005

Studies prosecuted on relics in those 17 bronze workshops that have been thus far excavated show that these workshops may be roughly classified into a royal workshop, a state-operated workshop and a private workshop depending upon by whom they were operated. Workshops in the Gyeongju area developed from a small royal handicraft manufacturing to a large state-operated handicraft manufacturing scale, and then later on gradually changed to a private handicraft manufacturing industry. The royal bronze workshops were operated in a small scale, as shown from the relics excavated at Wolseong(月城), Imhaejeonji(Anapji:雁鴨池) and their neighborhood places around Hwangnam_dong(皇南洞). The state-operated bronze workshops are concentrated upon one point around Dongcheon-dong(東川洞), Gyeongju city. On the other hand, in the state-operated workshop stage, a broad street was built by a workshop, which is presumed to aim to thoroughly transport materials needed for the workshop. And the point that wastes from bronze workshops were used for road repairs indicates that road repair works were carried at the bronze workshops near the road. The private workshop as a new type of workshop was operated by the aristocracy. For that purpose, craftsmen belonging to state-operated workshops or individual artisans were absorbed into the aristocracy-operated workshops. These types of workshops were pervaded throughout the city. When private workshops came to emerge in the houses of the aristocracy, the operating subjects of workshops began to change from state-operated to private workshops. Temple workshops were located at a Buddhist temple within the Court and directly produced things needed for the court, including bronze foundries. As aforementioned, through the presence of bronze workshops operated in the Silla Court, we can identify the relationships between their technical level and trading areas and among their origin, supply and demand sources, along with phases of social life in those days.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.268-286
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• 2018

The eutrophication and algal blooms by harmful cyanobacteria (CyanoHAs) and freshwater redtide (FRT) that severely experiencing in typical regulated weir system of the Nakdong River are one of the most rapidly expanding water quality problems in Korea and worldwide. To compare with the factors of rainfall, hydrology, and dominant algae, this study explored spatiotemporal variability of the major water environmental factors by weekly intervals in eight weir pools of the Nakdong River from January 2013 to July 2017. There was a distinct difference in rainfall distribution between upstream and downstream regions. Outflow discharge using small-scale hydropower generation, overflow and fish-ways accounted for 37.4%, 60.1% and 2.5%, respectively. Excluding the flood season, the outflow was mainly due to the hydropower release through year-round. These have been associated with the drawdown of water level, water exchange rate, and the significant impact on change of dominant algae. The mean concentration (maximum value) of chlorophyll-a was $17.6mg\;m^{-3}$ ($98.2mg\;m^{-3}$) in the SAJ~GAJ and $29.6mg\;m^{-3}$ ($193.6mg\;m^{-3}$) in the DAS~HAA weir pools reaches, respectively. It has increased significantly in the downstream part where the influence of treated wastewater effluents (TWEs) is high. Indeed, very high values (>50 or $>100mg\;m^{-3}$) of chlorophyll-a concentration were observed at low flow rates and water levels. Algal assemblages that caused the blooms of CyanoHAs and FRT were the cyanobacteria Microcystis and the diatom Stephanodiscus populations, respectively. In conclusion, appropriate hydrological management practices in terms of each weir pool may need to be developed.

• Korean Journal of Heritage: History & Science
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• v.37
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• pp.91-120
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• 2004

The Yan mountain area of the northern part of Hebei province and its local neighbor area is categorized main-distribution area of the northern bronze culture of the Eastern Zhou period(770bc~221bc). Recently, it was discovered the concrete character of the culture by a large scale excavation of the Yuhuangmiao cemetery at Jundu mountain. In the chinese scholarship, the cultural character of this area has established the independent cultural type that is distinguished from the Bronze culture of existing. In this paper, I have as a target of analysis remains relate to the Yuhuangmiao culture of the mountain area of northern Hebei in the Eastern Zhou period. And I would like to judge about diverse infuluential relationships of the character of the Yuhuangmiao curture and the Bronze culture, especially burials, burial customs and the characters of the excavated article. In particular, diverse infuluential relationships of the upper Xiajiadian culture Ordos bronze culture and The Central Plains cultural from The Yan state have a important meaning to understand about the character of the Yuhuangmiao culture and the beginning development process. Ultimately, it is peculiar characters of the Yuhuangmiao culture that a shaft gave with stone compartment protecting a coffin as a symbolic form, mask-burial customs such as mainly burials of the living with the dead dogs, a drum shaped jar, a tripod jar with two handles, a short bronze sword with circle hilt, Central Plains cultural bronze containers, bronze halberd and horse-shaped accessories of cartage horse trapping are distinguished from a local neighbor, the bronze culture from northern. The territory of time-space of The Yuhuangmiao culture can be dominately recognized bewteen the upper Xiajiadian culture and Ordos bronze culture. It is the Yan culture after the middle Warring States Period considering with the peculiar chacters which reflected by burials and bural customs and diverse infuluential relationships with peripheral cultures.

• Korean Journal of Environment and Ecology
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• v.33 no.4
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• pp.378-401
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• 2019

This study generated a list of plants in eight sections from the Baekdansa ticket office (874m) to Cheonjedan (1,560m) divided in the interval of 100m above sea level to examine the species diversity patterns and distribution changes of the vascular plants at different altitudes in Taebaeksan National Park. Four site surveys found a total of 385 taxa: 89 families, 240 genera, 345 species, 5 subspecies, 34 varieties, and 1 form. A result of analyzing the change of species diversity along elevational gradients showed that it decreased with increasing elevation and then increased from a certain section. A result of analyzing habitat affinity types showed that the proportion of forest species increased with increasing elevation. On the other hand, the ruderal species appeared at a high rate in the artificial interference section. A result of comparing the proportion of woody and herb plants showed that the woody plants gradually increased with elevation and rapidly decreased in the artificial interference section. On the other hand, the herb plants showed the opposite trend. A result of analyzing the change of distribution of species according to altitude with the DCA technique showed that the vascular plants were divided into three groups according to the elevation in order on the I axis with the boundaries at 900m and 1,300m above sea level. The arrangement of each stand from right to left along the altitude on the I axis with a significant correlation with warmth index (WI) confirmed that the temperature change along the altitude could affect the distribution of vascular plants, composition, and diversity. Therefore, the continuous monitoring is necessary to confirm ecological and environmental characteristics of vegetation, distribution ranges, changes of habitat. We expect that the results of this study will be used as the basic data for establishing the measurement measures related to the preservation of biodiversity and climate change.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.287-292
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• 2019

Pseudomonas tolaasii causes brown blotch disease on the oyster mushroom (Pleurotus ostreatus). Various pathogenic strains of P. tolaasii were isolated and divided into three subtypes, $P1{\alpha}$, $P1{\beta}$, and $P1{\gamma}$. For phage therapy, bacteriophages against to these subtype strains were applied to mushroom cultivation and very successful to prevent from the disease. In this study, bacteriophages were isolated against the representative strains of subtype pathogens and their polyclonal antibodies were synthesized to investigate structural relationship among capsid proteins of phages. Phage preparations over $10^{10}pfu/mL$ were injected to rabbit thigh muscle and polyclonal antibodies were obtained after three times of boost injection. Titers of the antibodies obtained were over $2{\times}10^7Ab/mL$ for the phage ${\phi}6264$, $1{\times}10^6Ab/mL$ for the phage ${\phi}HK2$, and $1{\times}10^7Ab/mL$ for the phage ${\phi}HK19$ and phage ${\phi}HK23$. High specific activities were observed between antibodies and the corresponding bacteriophages. Some cross-reactivities between the antibodies and non-corresponding bacteriophages were also measured. Antibody $Ab{\phi}6264$ inactivated all phages of $P1{\alpha}$ subtype and only phage ${\phi}HK16$ among $P1{\beta}$ subtype phages. Antibody $Ab{\phi}HK23$ of $P1{\gamma}$ subtype neutralized all phages of $P1{\beta}$ subtype as well as the phage ${\phi}HK23$, showing the widest phage-inactivation range. When the structural-similarity studies of phages were investigated by using phage antibodies, closeness obtained by phylogenetic analysis of 16S rRNA genes of pathogenic strains were quite different from that of polyclonal antibody-specific structural similarity of phage capsid proteins. In conclusion, there is weak correlation between the host strain specificity of bacteriophage and its capsid structural similarity measured by phage antibodies.

• Journal of Life Science
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• v.29 no.8
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• pp.895-903
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• 2019

The aim of the present study was to improve the cell viability of human dental papilla derived single-induced pluripotent stem cells (iPSCs) using a Rho-associated protein kinase (ROCK) inhibitor, Y-27632. The iPSCs were produced using an episomal plasmid-based reprogramming method. After cell separation using trypsin, the iPSCs were treated with 0, 0.5, 1, 2.5, 5, 7.5, or $10{\mu}M$ Y-27632 for 5 d. Cell viability increased significantly following the $5{\mu}M$ Y-27632 treatment (p<0.05). When the iPSCs were exposed to medium containing $10{\mu}M$ Y-27632 for 0, 1, 2, 3, 4, and 5 d, the cell viability rate increased significantly in accordance with the cell viability rate (p<0.05). To evaluate the effect of the Y-27632 treatment on stemness characteristics, the expression of stem cell-specific transcripts and telomerase activity were investigated in the iPSCs treated with $10{\mu}M$ Y-27632 for 5 d. The expression levels of stem cell-specific transcripts, such as OCT-4, NONOG, and SOX-2, and telomerase activity were not significantly different in the iPSCs treated with $10{\mu}M$ Y-27632 as compared with those of untreated control iPSCs (p>0.05). Taken together, the results demonstrated that cell viability can be improved by treatment with the ROCK inhibitor Y-27632, without losing iPSC stemness characteristics.

• Korean Journal of Heritage: History & Science
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• v.40
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• pp.73-104
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• 2007

Centering around ruins recognized of being relatively early stage related to flat tile and brick, excavated in Silla capital area, the study attempted elementary approach to seek the appearance time of every remain through comparing them from the excavated cases and production methods of Short beating, Medium beating plate, Long beating plate and Stamped-roof tile. Gyeongju began to use the short beating plate made of tile-less plates or tile plate and increased its quantity. That is deemed to be due to efficiency of beating plate making methods, and moreover to be limited only for use in the palace castle and offices. That is, making short beating plates is presumed to be made merely under some definite objectives. Medium beating plate has been spread to the whole country since Silla and Baekje united. Differently from Koguryo and Baekje, Silla had its unique Beating-plates making technology available for mass-production, which was spread to the whole country and resulted in disappearing of Koguryo and Baekje technology. Long beating plate was not nearly founded in Gyeongju area, but flat tile and common tile excavated in Sachunwang Temple site and Samrang Temple 3rd remains are known. In the outskirts of Gyeongju, long beating plate appeared between the latter half of 8C and the beginning of 9C. Until now, different views have raised to appearance of long beating plate of Unified Silla, which is expected to be clarified under the situation excavated by position relations. Stamped-roof title in Gyeongju is estimated as used after the datum point year 679. While in Baekje area, five stems and branches were involved, in Silla area, code or sign was shown much. The difference between two areas would be due to each other factory, and especially the marked contents werenot letters, which means it had been changed from Baekje s existing-methods. That is, it says the production environment changed owing to Silla's merging. And stamped-roof tile was temporarily used in Gyeongju but soon disappeared, which was because Silla beating plates made under cylinder-shaped tile barrel(圓筒瓦桶) and hitting-pressing of Medium beating plate had beenspread to the whole country, so the production technology of Koguryo and Baekje was naturally dismissed. In consequence, the mergence by Silla brought about unification of each nation's special technology.

• Korean Journal of Poultry Science
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• v.46 no.2
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• pp.105-115
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• 2019

In this study, viability, growth performance and egg production performance were investigated to determine the productive characteristics of 12 Korean domestic chicken varieties which have been collected and conserved for over 25 years in National Institute of Animal Science, Rural Development Administration, Korea. The 1,134 hens were tested and their production traits including survival rate, body weight, age at first egg laying, hen-day and hen-housed egg production, egg weight, and egg quality were measured. Survival rate was the highest in Korean Rhode-D and Korean Native Chicken (KNC) White and the lowest in Korean Cornish Brown (92.2% and 54.3%, respectively). Body weights from 4 to 50 wks were consistently high in the order of Korean Cornish, Korean Rhode, KNC, Korean Ogye, and Korean Leghorn breeds. There was no significant difference in weight between varieties within a breed. Age at first egg laying was the shortest in Korean Leghorn, while it was the longest in Korean Cornish. The hen-day egg production from $1^{st}$ egg to 57 wks was the highest in Korean Leghorn-K, and the lowest in Korean Cornish Brown. Egg weight was the heaviest in Korean Leghorn-F and the lightest in KNC White. The Haugh unit was the highest in Korean Rhode-C and the lowest in Korean Ogye. Taken together, these results suggest that it is desirable that the Korean Cornish variety is improved as the Korean meat breed because of its excellent growth ability, the Korean Leghorn variety is improved as the Korean layer breed because of its good laying performance, and the Korean Rhode and KNC varieties are improved as strong viable breeds because of their good survival rate.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.174-188
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• 2019

The present study was carried out to investigate the emulsifying properties of heat-treated octenyl succinic anhydride(OSA) starch and the interfacial structure at oil droplet surface in emulsions stabilized by heat-treated OSA starch. First, the aqueous suspensions of OSA starch were heated at $80^{\circ}C$ for 30 min. Oil-in-water emulsions were then prepared with the heat-treated OSA starch suspension as sole emulsifier and their physicochemical properties such as fat globule size, surface load, zeta-potential, dispersion stability, confocal laser scanning microscopic image(CLSM) were determined. It was found that fat globule size decreased as the concentration of OSA starch in emulsions increased, showing a lower limit value ($d_{32}:0.31{\mu}m$) at ${\geq}0.2wt%$. Surface load increased steadily with increasing OSA starch concentration in emulsions, possibly forming multiple layers. In addition, fat globule sizes were also influenced by pH: they were increased in acidic conditions and these results were interpreted in view of the change in zeta potentials. The dispersion stability by Turbiscan showed that it was more unstable in emulsions at acidic condition. Heat-treated OSA starch found to adsorb at the oil droplet surface as some forms of membrane (not starch granules), which might be indicative of stabilizing mechanism of OSA starch emulsions to be steric forces.

• The Korean Journal of Mycology
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• v.47 no.1
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• pp.51-61
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• 2019

The goal of this study was to elucidate wild yeast diversity of Geumgang midstream near Sejong metropolitan autonomous city, Korea. Thirty-seven strains of 32 species of wild yeasts were isolated from 43 water and soil samples under the Bulti bridge of Sejong city, Korea. Seven yeasts of each Candida spp. and Cryptococcus spp. were the predominant species isolated from samples near the Bulti bridge. Holtermanniella takashimae SW048 (NNIBRFG9314), Cystofilobasidium infirmominiatum SW013 (NNIBRFG9310), Mrakia cryoconite SW015 (NNIBRFG9316), Pichia sporocuriosa SW085 (NNIBRFG9326) and Cryptococcus aspenensis SW008 (NNIBRFG9309) represented novel yeast strains found in Korea for the first time. All of these previously unrecorded yeasts, except for Mrakia cryoconite SW015 had ascospores and grew well in yeast extract-peptone-dextrose (YPD), yeast extract-malt extract (YM) and potato-extrose (PD) media. Pichia sporocuriosa SW085 grew well in vitamin-free medium and Holtermanniella takashimae SW048, which was a halotolerant wild yeast, grew well YPD medium containing 5 % NaCl. Twenty-six strains representing eight species of wild yeast were isolated from 22 water and soil samples under the Haetmuri bridge of Sejong city, Korea. Candida pseudolambica (12 strains) and Aureobasidium pullulans (11 strains) were the predominant isolates from samples near the Haetmuri bridge. Occultifur kilbournensis HB060 (NNIBRFG9317), Sampaiozyma vanillica HB014 (NNIBRFG9332), Xenoramularia neerlandica HB039 (NNIBRFG9335), Candida norvegica HB315 (NNIBRFG9306), C. melibiosica HB316 (NNIBRFG9305), C. quercuum GB014 (NNIBRFG9307), and C. succiphila GB015 (NNIBRFG9308) represented novel yeast strains recorded in Korea for the first time. O. kilbournensis HB060 and X. neerlandica HB039 did not form ascospores or pseudo-mycelia. All of these previously unrecorded yeasts, except S. vanillica HB014 and X. neerlandica HB039, grew well in vitaminfree medium, and C. norvegica HB315 and C. succiphila GB015, which were halotolerant wild yeasts, which grew well in YPD medium containing 5 % NaCl.