• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.2
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• pp.105-112
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• 2006

This experiment was carried out to investigate the distribution, function of dry matter and competition in the grassland composed with mainly perennial ryegrass. Co-functions between grasses and weeds were evaluated by calculating methods; expected yield (P), agressivity, relative yield total (RYT), compensation index (CI) and morphological index (MI). Each values obtained were influenced by seeding method, grassland management and seasonal changes of co-functional index were identical. Expected yields of spring were lower than those of fall and improved by additional seeding to grassland in early spring time. In the relative yield total (RYT), all were under 1.0 which ranged from 0.17 to 0.41. Compensation index (CI) ranged from -0.3 to -0.6 and all values showed 'under compensation(+, --)' This means that the conditions of 'under compensation' could be improved through weed control by management of grassland in perennial ryegrass grassland. The results indicated that productivity of grassland mainly composed with perennial ryegrass is negatively affected by weeds like shepherd's purse, crabgrass and barnyard grass. As major weeds, shepherd's purse in spring, crabgrass in summer and barnyard grass in summer and fall were negatively functioned to productivity in the grassland composed with mainly perennial ryegrass.

• Journal of Conservation Science
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• v.30 no.4
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• pp.345-351
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• 2014

Chemical and Pb isotope analysis were performed in order to determine the origin of bronze artefacts excavated from the Inyongsaji site in South Korea. The result of ICP-MS shows that they are tin bronzes in which lead was not intentionally added during production. Pb isotope data analyzed by TIMS are plotted in the southern region of Korea and China of the distribution map drawn by Mabuchi(1985). On the other hand, the identical isotope data are plotted in the Taebaek basin and the Olcheon metamorphic belt correspondent to zone2 and zone3 respectively. It is believed that the isotope data on the tin bronzes which have very low lead content can be used to trace the origin of copper ore rather than those of either lead or tin ore. Pb istope analysis allows diverse interpretation as it can be applied to any object containing trace amounts of lead. In addition, accumulation of isotope data as well as further studies will improve reliability of the provenance studies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.219-225
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• 1978

Several samples of tile dried purple laver grown and processed at the major laver producing districts, i. e Mokpo, Wando, Hadong and Jangrim, along the southern coast of Korea were Quantitatively investigated to determine composing patterns of the fatty acids by gas-liquid chromatography. The total lipid contents in dried purple laver of Hadong were $1.8\%$ being the highest value. Upon analyzing fatty acid composition, some differences were observed in their quantitative distribution at different growing places. Dried purple laver of Wando contained mainly $C_{16:0},\;C_{18:1},\;C_{16:1}\;and\;C_{17:0}$ fatty acids, that of Mokpo contained $C_{16:0},\;C_{20:5},\;C_{18:1}\;and\;C_{16:1}$ fatty acids, and that of Hadong $C_{16:0},\;C_{20:5},\;C_{18:0}\;and\;C_{20:1}$ fatty acids, and that of Jangrim $C_{20:5},\;C_{16:0},\;C_{18:1}\;and\;C_{18:0}$ fatty acids, each in order of acid quantity. In regard to the composing pattern of carbon number of fatty acids, the dried purple laver o Mokpo, Hadong, and Jangrim contained $C_{16},\;C_{18}\;and\;C_{20}$ fatty acids with the identical distributional pattern, while that of Jangrim contained $C_{16},\;C_{18}\;and\;C_{17}$ fatty acids as major components. Dried Purple laver of Jangrim contained especially high amount of $C_{20:5}$ fatty acids.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.648-654
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• 2016

This paper investigates differences of tourism destination choices for sightseeing in Seoul between first-time visitors and repeat visitors. We constructed social network using secondary data from '2015 International Visitor Survey' and analyzed its density and centrality. Study results find that: (1) first-time and repeat visitors' tourism destinations are concentrated in areas located north of the Han river. The proximity of destinations suggests the positive effects resulting from the movement network. (2) As the result of degree centrality, closeness centrality, betweenness centrality, the highest ranking tourism destinations for both visitor groups are identical, but indexes of centralities in repeat visitors' destinations increase, including Shinchon/ Hongik University, Gangnam station, and Garosu-gil. Therefore, the roles of these destinations are becoming established as tourism hubs and are popular among younger visitors as well as attract repeat visitors. Results of this study will be a useful reference in developing and managing new tourism products.

• Journal of the Mineralogical Society of Korea
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• v.30 no.3
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• pp.113-126
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• 2017

In order to investigate the geological storage potential of $CO_2$, X-ray diffraction analysis were conducted for drilling core samples collected from the two drilling sites located in Yonil group of the Miocene Pohang Basin. As a result, various minerals were identified such as quartz, plagioclase, orthoclase opal-CT, smectite, mica, illite, kaolin mineral, chlorite, calcite, gypsum, pyrite, dolomite, and siderite. Smectite was detected in almost all of core samples, and relatively large amounts of smectite were observed in the cores from deeper strata. Opal-CT, mainly occurred in the upper interval of cores, was formed by diagenesis of amorphous diatoms. It shows a tendency that d101 value of cristobalite decreases with depth from $4.10{\AA}$ to $4.05{\AA}$. The almost identical variations in mineral composition with depth are observed at the two sites. This fact indicates that rocks distributed at the two sites were probably deposited in the similar depositional environments. It is determined that the strata in the study area can play roles of cap-rock for $CO_2$ storage, because the considerable amounts of smectite were contained in the rocks through the cores.

• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.5-12
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• 2009

Soil samples from the King Sejong Station in Antarctic and Vladivostok were tested in the laboratory and specific gravity, compaction curve, grain size distribution were determined. The effect of temperature change on the thermal conductivity, unfrozen water content, compressive strength were investigated. In addition, the change of tensile strength with temperature of the soil from Vladivostok was measured. Samples for the compressive strength test and tensional strength test were prepared in a mould with a fixed volume to prevent swelling. Also the effects of temperature and water content change on those strength were compared. Results from the thermal conductivity test showed that thermal conductivity values for both soils was larger at temperatures below freezing than those above freezing. The unfrozen water content dropped rapidly within a temperature range of $0{\sim}-5^{\circ}C$ and then gradually decreased further $-20^{\circ}C$. Compressive strength test results showed various stress/deformation curves with a change in water content. Sandy soil of the King Sejong Station had a much larger strength than ice at an identical temperature, while clayey soil of Vladivostok had a smaller strength than ice in the initial stage, but showed a larger strength at temperatures belows $-15^{\circ}C$. Tensile strength tests revealed an increase in the strength with a decreasing temperature.

• The Journal of Information Technology
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• v.2 no.2
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• pp.199-215
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• 1999

A quantitative analysis was conduct on the economic effect of electronic commerce according to the method of constructing the internet. As a consequence, it was information retrieval cost that had the most cost retrenchment effect in connecting the internet by telephone, which saved about 353,700 won. And it was found that the dedicated line to electronic commerce saved 420,600 won of information retrieval cost and a considerable amount of 319,900 won of brokerage expenses and physical distribution expenses. In terms of value, it was found that the telephone line reduced the time of order process by 8.25%, whereas the dedicated line did so by 9.41% and therefore saved more time than the telephone line. It was found that the dedicated line convenient to use had the higher effect by about 1.2%, respectively than the telephone line in terms of the effective construction of corporate image and the increase of potential buyers. In terms of business management, the intensification of corporate competitiveness improved by 10.00% in case of less than 10 times and by 11.53% in case of 50 to less than 50 times. And it was found that the effect of profit increase as the number of inquiries was large. That is, it was found that the effect of profit increase was 10.88% when the number of inquiries was less than 10 times but it increased to 14.00% in case of 50∼1ess than 100 times. The limitation of this study is that because the size of samples through mail, interview and E-mail was not large, its results have some limitation in applying them to every firm. That is, since the improvement effect of the intrafirm business method, unnecessary repeated manual paperwork and the use effect of being able to maintain the close relationship with to the parties to trades in the process of prompt receipt and delivery of documents are long-term and indirect effects, they have some limitation in that they can not be measured as coefficients but only as scales. Thus, firms using electronic commerce have difficulty enjoying a uniformly identical effect. Therefore, to revitalize electronic commerce, it is thought that government, the academic community and the business world all need to make much research into and sustained investment in electronic commerce.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.1
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• pp.34-39
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• 2007

Penaeidins are members of a special family of antimicrobial peptides existing in several species of shrimp and play a crucial role in the immunological defense of shrimp. In this study, we isolated and characterized one EST clone (penaeidin) from cDNA library of fleshy prawn Fenneropenaeus chinensis hemocytes. Amino acids sequence comparison and phylogenetic analysis with other known penaeidins revealed that our clone was completely identical to F. chinensis Penaeidin 3-2 (Accession no. ABC33920), which composed of 71 amino acids with a putative signal peptide (1-19) and a cysteine-rich domain (C-terminal part). The expression and distribution of Penaeidin 3-2 transcripts in shrimp were detected in hemocytes, hepatopancreas, and muscles, and that Penaeidin 3-2 was constitutively expressed mainly in hemocytes. The artificial infection of white spot syndrome virus to F. chinensis resulted in Penaeidin 3-2 mRNA up-regulation in hemocytes, suggesting that the possible role of Penaeidin 3-2 in host defense system of F. chinensis.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.942-948
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• 2005

New polymorphism of major histocompatibility complex B-G genes was investigated by amplification and digestion of a 401bp fragment including intron 1 and exon 2 using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique with two restriction enzymes of Msp I and Tas I in eight breeds of Chinese indigenous chickens and one exotic breed. In the fragment region of the gene, three novel single nucleotide polymorphisms (SNPs) were detected at the two restriction sites. We found the transition of two nucleotides of A294G and T295C occurred at Tas I restriction site, and consequently led to a non-synonymous substitution of asparagine into serine at position 54 within the deduced amino acid sequence of immunoglobulin variable-region-like domain encoded by the exon 2 of B-G gene. It was observed at rare frequency that a single mutation of A294G occurring at the site, also caused an identical substitution of amino acid, asparagine 54-to-serine, to that we described previously. And the transversion of G319C at Msp I site led to a non-synonymous substitution, glutamine 62-to-histidine. The new alleles and allele frequencies identified by the PCR-RFLP method with the two enzymes were characterized, of which the allele A and B frequencies at Msp I and Tas I loci were given disequilibrium distribution either in the eight Chinese local breeds or in the exotic breed. By comparison, allele A at Msp I locus tended to be dominant, while, the allele B at Tas I locus tended to be dominant in all of the breeds analyzed. In Tibetan chickens, the preliminary association analysis revealed that no significant difference was observed between the different genotypes identified at the Msp I and Tas I loci and the laying performance traits, respectively.

• Journal of Bio-Environment Control
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• v.13 no.3
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• pp.162-166
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• 2004

Air temperature variation along the length of the air duct in an air-heated plastic greenhouse was large, 13 ～ 15$^{\circ}C$ between the front and the rear side of a greenhouse. To reduce this temperature variation, a new PE-film air duct having a small duct inside a large duct (double duct) was developed. This double duct was consisted of an inner duct with air outlets at a 0.15 m interval and an outer duct with air outlets at a 2.5 m interval. Diameters of the air outlet holes were 7, 15, and 35 cm from the front to the end of the inner duct film, while identical 10 cm holes were used on the outer duct film. As a result, air temperature was $46^{\circ}C$ at the beginning side and $47^{\circ}C$ at the ending side, while the conventional single duct had $53^{\circ}C$ at the beginning point and $38^{\circ}C$ at the ending point with a variation of $15^{\circ}C$. Height of a cucumber crop grown in a greenhouse with the new double air duct system was 65.5 cm, 14% increase as compared to that in a greenhouse with a conventional air duct system. Total fruit yield per l0a greenhouse in a greenhouse with the new double air duct system was 4,616 kg, which was 17% greater than that in a greenhouse with a conventional air duct system. Amount of heating oil consumption during March 3 to April 24, 2002 was 3,233 L per l0a greenhouse with the new double air duct system, which was 13% less than that with a conventional air duct system.