• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.152-158
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• 2000

Background : No association between schizophrenia and dopamine D4 receptor polymorphisms have been reported. Despite these results, it is premature to exclude the association. It has been suggested that the susceptibility to develop schizophrenia could result from variation at a number loci which may interact or coact with each other. Therefore, we investigated a possible association of combinations of exon III 48bp polymorphism[D4E3] and exon I 12bp polymorphism of the DRD4 gene [D4E1] with schizophrenia. Methods : 207 unrelated Korean schizophrenic patients and 191 healthy controls were recruited. DRD4 genotype was established using the polymerase chain reaction. Statistical analysis consisted of ${\chi}^2$ tests for Hardy-Weinberg proportions and genotypic and allelic frequencies in the patients and control groups. Results : There were no statistically significant differences in the each polymorphisms between schizophrenics and controls. And all genotype frequencies were within Hardy-Weinberg expectations. When the combinations of the polymorphism in schizophrenia and controls were compared, however, there were significant differences at $A1A2^*2/4$ in the distributions of the combinations of D4E1 and D4E3(p<0.01). Conclusions : These findings suggest that the certain combination of D4E1 and D4E3($A1A2^*2/4$) has the protective role to a susceptibility for schizophrenia.

• Research in Plant Disease
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• v.19 no.4
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• pp.243-253
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• 2013

Rice blast is one of the most serious disease threatening stable production of rice. Breeding of resistant cultivars has been used as the most effective and useful method to controll rice blast caused by Magnaporthe oryzae. To collect rice blast isolates in fields and test their pathogenicity on new cultivars are important for establishment of new resistant cultivars breeding program of rice. Pathotypes of Korean rice blast isolates have been categorized to Korean differential race system developed in 1985. However, it is little known about genetic background of Korean differential cultivars, so that it is hard to understand for relationship between each pathogen and each host plant at genetic level. In this study, we suggested necessity of a new differential system by analyzing pathogenic responses between 24 monogenic rice lines and 200 Korean rice blast isolates. In addition, we determined the nine representative resistant genes based on the resistance responses of the monogenic lines to rice blast isolates, indexed resistant responses of the monogenic lines to ten representative rice blast isolates and selected 30 Korean representative rice blast isolates proper to Korean system. We think the newly developed differential race system can be broadly used to select resistant cultivars to rice blast in Korea.

• Economic and Environmental Geology
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• v.50 no.2
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• pp.85-96
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• 2017

Gold mineralization of Samjeong and Yongjang gold mines in Uichang area shows characteristics of Bonanza-type gold deposits. Ores are mainly developed along the contact parts between quartz vein and arkosic sandstone beds(Fe-rich bed) in sedimentary rock. Electrum, silver sulfide and sulfate minerals are mainly in the ores. On the other hand, gold mineralization is less developed in cherty rock and andesitic rock than arkosic sandstone. The study highlights characteristics of gold precipitation in the deposit on the basis of numerical modelling of the reactions between the assumed hydrothermal ore fluids with multicomponent heterogeneous equilibrium calculations. Aqueous species, gases and minerals, containing electrum are included in the calculations. The reaction result between hydrothermal ore fluids and arkosic sandstone show that pH increasing in the ore-forming fluid would trigger precipitation of quartz, chlorite, sericite, chalcopyrite, galena, pyrite, electrum, actinolite and feldspar. The numerical modelling also illustrates the drastic increase of pH and desulfidation lead to precipitation of electrum. Ag/Au ratios in the ore vary with pH conditions and subsequently precipitation of silver-bearing sulfides such as acanthite and polybasite. The modelling of the reaction between andesitic rock and ore-forming fluid shows that mineral assemblages of the case are analogous to ones of the reaction between arkosic sandstone and fluid except the latter has little portion of electrum. The abovementioned modelling results suggest that gold-silver mineralization is bounded by host rocks at the study area.

• Journal of Conservation Science
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• v.35 no.5
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• pp.453-469
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• 2019

The celadon jar with inscription of 'the Fourth Sunhwa Year' is an important chronology that shows the conditions of production of the early celadon due to the inscription on the bottom including its purpose, application, and the producer. This celadon jar has been restored several times in the past. However, concerns over the structural stability, such as the separation and level differences in the joined cracks, have risen because of the aging of the repair materials, which were subjected to various environmental changes over a long time. By examining the conditions of preservation, the major damage was identified as the '入' shaped crack on the front, the 'V' shaped restored part and the crack on its left side, and the 'J' shaped crack on the back side. In the past, the cracks were found to be joined using a refined lacquer containing camphor, drying oil, rosin, etc. mixed with soil powder. The joint line was repainted with the refined lacquer and covered with gold powder. The missing parts were restored with gypsum and colored with acrylic color. After that, the repair materials were aged and emergency treatment was performed at the National Museum of Korea in 1981. At that time, Cemedine C or Cemedine C mixed with microballoons was used for reinforcing the cracks. Conservation treatment focused on removing the past repair materials and reinforcing the physically fragile parts by joining and restoring them based on the examination of the preservation condition. in addition, the area around the restored part was colored for future exhibition.

• The Journal of the Petrological Society of Korea
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• v.21 no.3
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• pp.277-285
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• 2012

Hawaiite which distributed in Sanjideungdae of Sarabong cinder cone and Biseokgeori area in northern part of Jeju island, contains phenocrysts of titanium-rich hornblende (kaersutite) and plagioclase with microphenocrysts of olivine, pyroxene and very small amounts of K-feldspar lath and apatite. Kaersutite is mostly euhedral or subhedral phenocrysts having opaque reaction rim. And kaersutite in Sanjideungdae area completely replaced to opaque minerals showing pseudomorph. Also it may be seen partly replacement of pyroxene by kaersutire as reaction rim. It is considered that hydration reaction had occurred with fluids. The crystallization pressure of kaersutite using pressure-$Al^T$ geobarometer is approximately 6.3 kb in Sanjideungdae area and 4.9 kb in Biseokgeori area, respectively. As a result, fluid injection to magma and crystallization of kaersutite of Sanjideungdae hawaiite is deeper than that of Biseokgeori hawaiite, and it was growed to phenocrysts through crystallization. It is estimated that kaersutite of Biseokgeori hawaiite originated from crystallization from the host magma, based on the euhedral nature of the phenocrysts and on the presence of apatite inclusions.

• The Korean Journal of Financial Management
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• v.23 no.1
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• pp.69-100
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• 2006

We examine the effect of controlling shareholders ownership structure and related-party transactions(hereafter 'RPT') of publicly traded companies on their firm values during the post-IMF period. In the multivariate regression analysis using control variables such as firm size, capital structure, investment, dividend, profitability and industry dummy that might affect firm values, we find that there exists a significant negative relation between the controlling shareholders ownership structure and firm values proxied by Tobin's Q, and also find that there is a significant negative relation between RPT and the firm values. Those evidences seem to support the controlling shareholders' expropriation hypothesis. Additionally, we investigate the relation between ownership structure and rim value through the piecewise regression analysis. We find a significant 'inverse' U-shape pattern between the controlling shareholders ownership structure and firm values. This result is quite different from the existing literatures that have usually reported an U-shape pattern. In conclusion, the findings in this study do not support the notion that the ownership concentration to the controlling shareholders does negatively affect the firm values monotonically.

• Journal of Life Science
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• v.30 no.10
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• pp.912-918
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• 2020

The Korean native black goat (Capra hircus coreanae) is the goat species to be officially registered in Korea under the Food and Agriculture Organization. The object of this study is to establish a set of microsatellite (MS) markers for the individual identification and parentage verification of goats. In this study, we analyzed alleles of MS markers in crosses between Korean native black goats and crossbred goats (n=304 animals), and, based on the diversity of alleles for each marker, we selected 11 MS markers for individual identification and parentage verification. Using these 11 MS markers, the probabilities of different individuals with the same genotype being found within random and half-sib mating populations were 5.58×10^-10 and 1.15×10^-7, respectively. The parentage verification accuracy was 0.999996 when information about the parents was available and 0.999833 with no information. Thus, even given the total rearing population of 576,150 animals in South Korea, we concluded that these markers could be used for the individual identification and parentage verification of goats. Moreover, by analyzing the genetic relationships between the four lines of Korean native black goats and the crossbred goats, we verified the genetic characteristics of Korean native black goats, confirming their conservation value as a unique genetic resource.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.116-122
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• 2013

We investigated characteristics and self-incompatibility genotypes of 11 crabapple cultivars to introduce a new pollinizer of 'Fuji' apple tree in Korea. Flowering dates of eleven crabapples were two to seven days earlier than that of 'Fuji'. The rate of pollen germination in vitro was ranged from 85.6% to 98.0% except 'Virginia'. Controlled pollination treatment with each crabapples to 'Fuji' increased fruit set rate about 20.4% to 34.4%, the number of seed per fruit about 13.8% to 42.3% and fruit weight about 7.4% to 16.7% compared to open pollination. Tested crabapples were resistant to peach fruit moth, brown leaf spot and sooty blotch in general. A PCR amplification method using S-RNase primers was carry out in eleven crabapples. S-alleles, $S_3$, $S_5$, $S_9$, $S_{10}$, $S_{20}$, $S_{26} from six crabapples were determinated. Through sequencing analysis, $S_5$ ('Manchurian', 'Virginia') and $S_9$ ('Yantaishagou') showed 100% homologous to previous result. Based on our results, it was recommended that 'Manchurian', 'Hopa A', 'Hanyaehanakaidou', 'Spectabilis' could be promising pollinzers for 'Fuji' apple cultivar.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.4
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• pp.227-236
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• 2016

In the present experimental study, the effect of gas- and liquid-injected methods on the formation of bubble and liquid slug at the merging micro T-junction of a square microchannel with dimensions $600{\mu}m{\times}600{\mu}m$ was investigated. Nitrogen and water were used as test fluids. The superficial velocities of the liquid and gas were in the range of 0.05 - 1 m/s, and 0.1 - 1 m/s, respectively, where the Taylor flow was observed. The bubble length, liquid slug length, bubble velocity, and bubble generation frequency were measured by analyzing the images captured using a high-speed camera. Under similar inlet superficial velocity conditions, in the case of gas injection to the main channel at the merging T-junction (T_gas-liquid), the lengths of the bubble and liquid slug were longer, and the bubble generation frequency was lower than in the case of liquid injection to the main channel at the merging T-junction (T_liquid-gas). On the other hand, in both cases, the bubble velocity was almost the same. The previous correlation proposed using experimental data for T_liquid-gas had predicted the present experimental data of bubble length, bubble velocity, liquid slug length, and bubble generation frequency for T_gas-liquid to be ~24%, ~9%, ~39%, ~55%, respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.3
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• pp.49-57
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• 2016

This study intended to analyze reinforcement effects of PSC I girder bridges to which prestresses are introduced using V type of external strands. So that series of bridge loading tests are carried out on existing PSC I girder bridge for the cases of before-reinforcement and reinforcement. The measured results from tests being analyzed and compared with the ones from MIDAS structural analyzing program, the reinforcing effects of the reinforcement system adopted in this study were investigated. It is found out that when the V type systems are applied to the bridge girders, the slope of load distribution factor curves become lower improving soundness of bridge upper structure. And also it is confirmed that the reinforcement system in this study can be taken as helpful for improvement of both flexural and shear ability of PSC I girder bridges, as well as dynamic behavior. Furthermore it is found when the elastic pads are applied to the system, dynamic reinforcing effects are maximized.