• Analytical Science and Technology
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• v.21 no.2
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• pp.148-157
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• 2008

To describe the lifetime prediction of gas turbine core parts serviced in some ten thousands rpms at over $1,000^{\circ}C$, the Larson-Miller Creep Curves, which are formed by creep rupture tests as the destructive experiment with parameters of stress and temperature, are used often, but not exact and reliable with errors of over some tens. On the other hand, this study shows a non-destructive method with increased accuracy and reliability. The SEM and TEM specimens were extracted by replica after polishing the local airfoil and root surfaces of the first stage scraped blade (bucket), serviced for 18,000 hours at $1,280^{\circ}C$ in Gas Turbines of Boryong. The observed TEM and SEM precipitates were digitalized for calculation of the average size. Here we could find the precipitate size grown from $0.45{\mu}m$ to $0.6{\mu}m$ during service and the grown precipitates to be still sound. From these results we could conclude that the scraped balde can be used for ten thous and hours additionally and for twenty thousand hours by additional heat treatments on the scraped blade.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.44-53
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• 2022

The purpose of this study is to plan and develop contents for training social skills using robots for elementary school students. Seven functions (guiding activity, providing reinforcement, guiding students behavior, team setting, presenting team order, timer setting, and checking scores) were developed by analyzing functions that robots can take charge of in the training contents. A total of 8 sessions of social skills training contents were developed by selecting social skills required for academic achievement and social interaction of elementary school students. The lesson consisted of providing positive and negative examples, modeling, role-playing, providing feedback on performance, and encouraging generalization stages using effective strategies for acquiring social skills. After developing social skills training contents using robots for elementary school students, so-called Friendly Friends (FF), a satisfaction survey was conducted on the field application of contents and participating students and teachers to examine the acceptance pattern. As a result, it was found that the participating students and teachers were satisfied with the contents. Finally, the meaning and the expected effects of the 'FF (Friendly Friends)' contents were discussed, and also, the matters to be considered when developing social skills training contents using robots in the future were suggested.

• Journal of the Korea Knowledge Information Technology Society
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• v.12 no.1
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• pp.69-78
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• 2017

KOIN (Korean medicine 人, http://www.koin.re.kr) is a Korean medicine knowledge portal developed for users who are interested in Korean medicine to share relevant information. The purpose of the present study is to seek methods for advancing the quality of the contents and services of KOIN to secure future users of the portal services before fully initiating the KOIN service. The crowd testing method was applied to test the functionality and usability of the current KOIN service, and domestic and international websites providing similar services were investigated and analyzed. About 150 errors were found in this functional testing procedure, but the identified functional problems were all corrected. An average score of 3.33 was calculated in the usability test, in which the reliability and the playfulness showed the highest and lowest score, respectively. We in this paper surveyed the 15 relevant websites with respect to KOIN in the traditional medicine and the modern medicine fields. The strengths and weaknesses of similar websites were analyzed to improve the KOIN services. In particular, it is shown that the evidence-based Korean medicine knowledge is KOIN's biggest strength. Users' needs and demand for the KOIN services will be continuously gathered to provide the Korean medicine knowledge services that the users require.

• Journal of the Economic Geographical Society of Korea
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• v.8 no.1
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• pp.153-169
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• 2005

In this study, we analysed the state of the fisheries in Chungnam around 1910 from Hangook Susanji. As a result, there were about 30 ports in the west coast area in Chungnam, and we can classify their locations into 5 types Type I is located in small and mid sized rivers. Type II is located in a costal port. Type III is ports facing the open sea, and type IV is ports in a bay. Type V is ports on islands of coast. Species of fish are porges, mackerels, sting rays, croakers, hairtails, shrimps, etc. The base of fishing porge was Jukdo and Yeondo. The fishing banks of croakers are formed from Chilsantan, Jeonlado to the area of seashore, Chungnam. Hairtails were caught near all the areas of seashore. Salt manufacturing is done near all coasts of Chungnam, Seocheon-bay, Ungcheon-bay, Ocheon-bay, Anmyeon island, Taean, Dangjin area, etc represent this work. Especially, the salt which was produced in Taeangun was so famous that it was called ' Taeansalt'. In the Kum-river area there were 32 fishing villages. Freshwater fish were caught in the upper stream area and the mouth of Geumgang, down stream, was the center for producing Baengeo. There were 23 fishing villages, and the species consisted of croaker, hairtail, Forge, gray mullet, sting ray, sharks, anchovy, shrimps, etc in Biin-bay. The coast of Boryeong had about 33 fishing villages, but their fishing industry was not developed more than their good salt manufacturing. Though there are records that Chunsu-bay had 28 fishing villages, Taean peninsula and Garolim-bay had about 70 fishing villages, and Asan-bay area had about 55 fishing villages, they were developed a little, but not more than Weir fisheries or salt manufacture on the base of salt area and the tideland because these areas were just for farming. South of Anmyeon island of West coast island areas is the biggest area of Stow nets on stakes fishing and the island areas down mouth of Kum river were centers for producing porge.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.142-149
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• 2005

This investigation was conducted to observe and verify the distribution and their occurrence between heavy metals and natural isotopes in the soil collected at the 40 locations from the abandoned coal mine areas to the sediment of Chungra reservoir located at Chungra-Myon Boryung city, Chungnam. The results of the investigation showed that there were distinctive differences of the contents for the heavy metals and the natural isotopes between the area influenced by the coal mine tailing and the non-influenced area. The amounts of the heavy metals were Pb ($1.32-29.96mg\;kg^{-1}$), Cd ($0.15-0.76mg\;kg^{-1}$), Cu ($0.28-49.67mg\;kg^{-1}$), and Cr ($1.31-13.18mg\;kg^{-1}$) while the averages were Cu ($12.43mg\;kg^{-1}$), Pb ($10.44mg\;kg^{-1}$), Cr ($4.87mg\;kg^{-1}$), Cd ($0.51mg\;kg^{-1}$). The standard deviations of Pb and Cu were significantly higher compared to other heavy metals investigated in this experiment. And the amounts of the natural isotopes measured from the dried soil samples were Pb-210 ($4.87dpm\;g^{-1}$), Th-234 ($3.52dpm\;g^{-1}$), Ra-226 ($2.88dpm\;g^{-1}$), Ra-228 ($7.30dpm\;g^{-1}$), K-40 ($58.06dpm\;g^{-1}$) for all locations whereas Cs-137 which is fall-out by nuclear experiment from atmosphere was rarely found. From these results we found that the amounts of natural isotopes such as Pb-210 (4.41%), Th-234 (3.60%), and Ra-226 (2.09%) were less than those found in the coal-tailing while the proportion of Ra-228 (266%) and K-40 (308%) were significantly higher than those in the coal-tailing. Also occurrence of correlations between the amounts of the heavy metals and the natural isotopes was proportionally related.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.3
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• pp.221-228
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• 2008

This experiment was carried out to investigate the actual outbreak status of rice black-streaked dwarf virus (RBSDV) disease in forage corn for securing the basic data to control of the disease all over the country from 2006 to 2007. Outbreak of the disease showed a wide difference according to regions and was severe in Icheon, Gochang, Kimje, Youngkwang, Kimchun, Youngju, Cheonan, and Boroung provinces in Korea. Outbreak rate of the disease was effected by planting time of forage corn. Disease rate was lower in corns planted from Apr. 26 to May 15 than in those of planted from April 10 to 25 or after May 31. The corn fields planted from April 26 to May 15 showed lower disease rate than that of planted from April 10 to 25 or after May 31. Also the outbreak rate of the disease was some difference according to corn varieties but was not genuinely resistant varieties to RBSDV. Dry matter yield of forage corn was significantly decreased depending on disease rate, and was highly negative correlation to disease rate. The forage corn infected with RBSDV was lower 3.2%, 3.6% and 12% in IVDMD, TDN, and RFV, and higher 3.7% and 4.5% in NDF and ADF than those of the healthy plant, respectively.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.623-632
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• 2011

To increase the anti-carcinogens phenylethylisothiocyanate (PEITC), myrosinase (MYR), and glutathione S-transferase (GST), genes related to PEITC pathway were isolated and the gene expressions were regulated by Agrobacterium transformation. Isolated cDNAs, MYR, and GST genes were 1,647 bp and 624 bp, respectively, and the protein expression was confirmed through pET system. Thereafter, we constructed a sense-oriented over-expressing myrosinase (pBMY) and RNAi down-regulated GST (pJJGST) binary vectors for the Chinese cabbage transformation. After the transformation, thirteen over-expressing transgenic Chinese cabbage plants (IMS) with pBMY and five down-regulated ones (IGA) with pJJGST were selected by PCR analysis. Selected $T_0$ transgenic plants were generated to $T_1$ plants by self-pollination. Based on the Southern blot analysis on these $T_1$ transgenic plants, 1-4 copies of T-DNA were transferred to Chinese cabbage genome. Thereafter, RNA expression level of myrosinase gene or GST gene was analyzed through real-time RT PCR of IMS, IGA, and non-transgenic inbred lines. In case of IMS lines, myrosinase gene was increased 1.03-4.25 fold and, in IGA lines, GST gene was decreased by 26.42-42.22 fold compared to non-transgenic ones, respectively. Analysis of PEITC concentrations using GC-MS it showed that some IMS lines and some IGA lines increased concentrations of PEITC up to 4.86 fold and up to 3.89 fold respectively compared to wild type. Finally in this study IMS 1, 3, 5, 12, and 15 and IGA 1, 2, and 4 were selected as developed transgenic lines with increasing quantities of anti-carcinogen PEITC.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.3
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• pp.165-173
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• 2007

In the previous study, we reported the antioxidative and cellular protective effects of Jeju native plant extracts. In this study, we investigated the anti-oxidative, anti-wrinkle and whitening effects of new 37 plant extracts collected from self-growing plants in Jeju island. Their anti-oxidant activities were measured by the 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging assay and reactive oxygen species(ROS) scavenging assay in $Fe^{3+}-EDTA/H_2O_2$ system. The cytoprotective properties of 37 plant extracts were assessed in the rose-bengal sensitized photohemolysis of human erythrocytes. The inhibitory effect of 37 plant extracts on tyrosinase were investigated to assess their whitening efficacy. Finally, their anti-elastase activities were measured to predict the anti-wrinkle efficacy in the human skin. The results showed that the extracts of Myrica rubra stem bark and Securinega suffruticosa have the free radical scavenging activity($FSC_{50}:\;5,\;8{\mu}g/mL$, respectively), and the extracts of Quercus acutissima leaf and Securinega suffruticosa stem bark have the prominent ROS scavenging activity($OSC_{50}:\;0.009{\mu}g/mL$). Photohemolysis of erythrocytes in the presence of rose-bengal as a sensitizer was inhibited by the extracts of Securinega suffruticosa stem bark and Salix koreensis stem(${\tau}_{50}$, 895 min, 640 min at 50 ${\mu}g/mL$, respectively. Myrica rubra stem bark extract(77.8% at 200 ${\mu}g/mL$) and Salix koreensis stem extract(76.2% at 200 ${\mu}g/mL$) also have the inhibitory effect on tyrosinase and elastase activities, respectively. These results indicated that the stem park of Myrica rubra, Securinega suffruticosa, and Camellia japonica, the stem of Salix koreensis, and the leaf of Quercus aqutissima and Camellia japonica could have e benefitial effects when they are added as ingredients in cosmetics.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.345-354
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• 2013

To understand the community structures of the vegetation of the beaches and coastal dunes of Seocheon-gun, Boryeong-si, Anmyeon-do, Taean-gun in Chungcheongnam-do and Buan-gun in Jeollabuk-do at the west coast of South Korea, a plant sociological vegetation survey was carried out to make a classification of correlation vegetation communities, a cluster analysis and an inorganic component analysis on the soil and plant body. Regarding the vegetation of the coastal dunes, plant communities were classified into 31 communities by correlation dominant species, and as a result of a cluster analysis on the vegetation communities, they were classified into five vegetation types such as Calystegia soldanella community, Rosa rugosa community, Imperata cylindrica community, Vitex tend community and Elymus mollis community. The soil pH was highest in Seocheon area ($7.54{\pm}1.18$) while lowest in Buan area ($6.29{\pm}2.15$), and regarding inorganic components, the nitrogen content was highest in Robinia while lowest in Imperata cylindrica. The soil PH of vegetation I was highest (8.23) among the five vegetation types, and the organic matter was lowest (71.58). As a result of CCA ordination analysis to examine the correlation among environmental factors, Calystegia soldanella community, Rosa rugosa community and Imperata cylindrica community among the five vegetation types were distributed while they were not affected by soil environmental elements, but Vitex tend community and Elymus mollis community were distributed mainly at the places with high $K^+$ content in the soil.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.323-330
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• 2013

This study was conducted to know the effect of major physical-chemical characteristics of soil to be in the area of indigenous and naturalized plant in the sand dune of the western coastal area of Korea. The study was performed on the sand dunes distributed across Taean-gun and Buan-gun and the study period was from April to October in 2010. Sixty nine of $5m{\times}5m$ study plots were installed and the distribution of plants were investigated. We measured the soil characteristics including soil pH, organic matter, total nitrogen, available $P_2O_5$, soil cation exchange capacity, exchangeable cation, EC and NaCl. As a result, soil texture was classified as sand, in case of average pH, NaCl, and EC of soil to be in the area of indigenous herbaceous plant were 7.77, 0.03% and $0.52ds.m^{-1}$, indigenous woody plant of the mean pH, NaCl and EC were 7.31, 0.01%, $0.23ds.m^{-1}$. In case of naturalized herbaceous plant of the mean soil pH, NaCl and EC were 7.12, 0.01%, $0.29ds.m^{-1}$, naturalized woody plant of the mean soil pH, NaCl and EC were 7.34, 0.01%, $0.20ds.m^{-1}$ respectively. On average, naturalize plants showed in low salinity concentration than indigenous plants.