• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.42.1-42.1
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• 2019

We observed 80 dense cores ($N(H_2)$ > $10^{22}cm^{-2}$) in the Orion molecular cloud complex which contains the Orion A (39 cores), B (26 cores), and ${\lambda}$ Orionis (15 cores) clouds. We investigate the behavior of the different molecular tracers and look for chemical variations of cores in the three clouds in order to systematically investigate the effects of stellar feedback. The most commonly detected molecular lines (with the detection rates higher than 50%) are $N_2H^+$, $HCO^+$, $H^{13}CO^+$, $C_2H$, HCN, and $H_2CO$. The detection rates of dense gas tracers, $N_2H^+$, $HCO^+$, $H^{13}CO^+$, and $C_2H$ show the lowest values in the ${\lambda}$ Orionis cloud. We find differences in the D/H ratio of $H_2CO$ and the $N_2H^+/HCO^+$ abundance ratios among the three clouds. Eight starless cores in the Orion A and B clouds exhibit high deuterium fractionations, larger than 0.10, while in the ${\lambda}$ Orionis cloud, no cores reveal the high ratio. These chemical properties could support that cores in the ${\lambda}$ Orionis cloud are affected by the photo-dissociation and external heating from the nearby H II region. An unexpected trend was found in the $[N_2H^+]/[HCO^+]$ ratio with a higher median value in the ${\lambda}$ Orionis cloud than in the Orion A/B clouds than; typically, the $[N_2H^+]/[HCO^+]$ ratio is lower in higher temperatures and lower column densities. This could be explained by a longer timescale in the prestellar stage in the ${\lambda}$ Orionis cloud, resulting in more abundant nitrogen-bearing molecules. In addition to these chemical differences, the kinematical difference was also found among the three clouds; the blue excess, which is an infall signature found in optically thick line profiles, is 0 in the ${\lambda}$ Orionis cloud while it is 0.11 and 0.16 in the Orion A and B clouds, respectively. This result could be another evidence of the negative feedback of active current star formation to the next generation of star formation.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.390-396
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• 2015

This study was carried out in order to closely examine quality index by shading level of 2-year-old (1-1 seedling) container seedling of Daphniphyllum macropodum which is known as the species of having shade tolerance that is evergreen broad leaved tree in the warm temperate region. The shading treatment was regulated with the shading level of full sunlight, and 35%, 55%, 75%, 95% of full sunlight. As a result of surveying growth according to the shading level, both height and root collar diameter were surveyed to be the highest with 45.1 cm and 8.22 mm, respectively, under 75% of shading. The next was surveyed to be 43.2 cm & 8.05 mm and 42.5 cm & 7.98 mm, respectively, in order of 35% and 55% in shading. Leaf, shoot, root, and whole dry mass production were the highest under 75% of shading. The next was higher in leaf, stem, and whole dry mass production under 55% of shading. A root was higher under 35% of shading in the next. H/D ratio was the range of 5.29~5.35 under the 35~75% shading that showed the relatively high height and root collar diameter. T/R ratio was the lowest with 1.17 under 35% of shading. It was 0.41 under 95% of shading as for LWR, 0.24 under 75%-95% of shading as for SWR, and 0.46 under full sun and 35% shading as for RWR. QI was the highest with 3.74 under 75% of shading. As a result of surveying the whole experiment, it is concluded that the production of D. macropodum seedling is more effective under 75% shading

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.5 no.1
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• pp.108-117
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• 1994

Twenty nine children with autism and thirty children with mental retardation were examined for association between autism and chromosomal disorders including fragile X. The peripheral blood was cultured in Medium 199 with methotrexate and without methorexate for 70 hours. Thirty metaphase cells in each case were karyotyped in all samples. Chromosomal abnormalities were found in 11 cases(37.9%) of autistic disorder and 10 cases (33.3%) of mental retardation, but in none of fragile(X)(q27.3) from all cases. Chromosomal abnormalities were present on group A, C, D and X in autistic disorder and on group A, B, C, D, E and X in mental retardation. No specific chromosomal region was found in both autistic disorder and mental retardation. Types of chromosomal disorders were only fragile and/or gap but no numerical abnormality was present in all cases. Number of cells which revealed fragile sites were 31 cells(3.6%) out of 870 cells in autistic disorder and 29 cells(3.2%) out of 900 cells in mental retardation Number of cells which revealed gaps were 43 cells(4.9%) out of 870 cells in autistic disorder and 35 cells(3.9%) out of 900 cells in mental retardation. Autistic disorder may not be directly correlated with fragile X but with nonspecific chromosomal breakages from these data.

• The Korean Journal of Malacology
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• v.29 no.3
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• pp.171-179
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• 2013

Arginine kinase (ArK) is known to play an important role in most invertebrates the level of ATP by phosphorylation of phosphagens in cell and immuninty in living organisms. ArK has been identified in many kinds of organisms ranging from invertebrate to vertebrate. However, no ArK gene has been cloned and investigated from N. samarangae. This leads us to identify ArK cDNA (NsArK) from the expressed sequence tag (EST) sequencing of N. samarangae. Sequence analysis indicated that the coding region of 1,065 bp contains 355 amino acid residues. Molecular phylogenetic analysis shows that NsArK had very high similarities with mollusca and arthropoda. In an attempt to investigate a potential role of NsArK in the digestive gland of N. samarangae, expression patterns were analyzed. RT-PCR analsysis shows that NsArK mRNA is induced in the rane of 1.2 fold at 6 hr by laminarin when compared with the control. The immunnologial and physiological role of NsArK remains to be further investigated in N. samarangae.

• Korean Journal of Ichthyology
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• v.32 no.4
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• pp.199-209
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• 2020

In order to clarify the taxonomic status of the Korean Macroramphosus species, which were previously confused, we investigated morphological and molecular variations of Macroramphosus (18 individuals) from Korea, and Macroramphosus (35 individuals) from Japan and Taiwan, and compared with those of M. scolopax from type locality (Mediterranean Sea). Although the Korean and Japanese specimens of Macroramphosus were clearly divided into two types in the first dorsal spine length (22.8~32.1% in A-type vs. 15.6~21.4% in B-type), distance between the first dorsal fin and second dorsal fin (6.4~9.7% vs. 8.6~13.3%), and body depth (20.0~28.0% vs. 17.3~22.6%), no genetic differences among all individuals of longspine snipefish between them were found at the specific level [d=0.0~3.3% in control region (CR); 0.0~1.3% in cytochrome b (cytb); 0.0~0.5% in cytochrome c oxidase subunit I (COI)]. Whereas, they were well distinguished in genetics (9.9~11.5% in CR; 3.8~4.6% in cytb; 1.2~3.6% in COI) from those of M. scolopax in Mediterranean Sea. It needs the scientific name of the longspine snipefish (M. scolopax) in Korea be changed as M. japonicus (and/or M. sagifue). However, our results could not find evidence of consistency between morphological and mitochondrial DNA variations which suggests that their differentiation event may occur fairly recently. Further studies using more sensitive markers such as microsatellite are needed to clarify the degree of gene flow between the two types.

• Korean Journal of Materials Research
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• v.22 no.1
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• pp.24-28
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• 2012

$In_2O_3$ films were deposited by RF magnetron sputtering on a glass substrate and then the effect of post deposition annealing in nitrogen atmosphere on the structural, optical and electrical properties of the films was investigated. After deposition, the annealing process was conducted for 30 minutes at 200 and $400^{\circ}C$. XRD pattern analysis showed that the as deposited films were amorphous. When the annealing temperature reached 200-$400^{\circ}C$, the intensities of the $In_2O_3$ (222) major peak increased and the full width at half maximum (FWHM) of the $In_2O_3$ (222) peak decreased due to the crystallization. The films annealed at $400^{\circ}C$ showed a grain size of 28 nm, which was larger than that of the as deposited amorphous films. The optical transmittance in the visible wavelength region also increased, while the electrical sheet resistance decreased. In this study, the films annealed at $400^{\circ}C$ showed the highest optical transmittance of 76% and also showed the lowest sheet resistance of $89{\Omega}/\Box$. The figure of merit reached a maximum of $7.2{\times}10^{-4}{\Omega}^{-1}$ for the films annealed at $400^{\circ}C$. The effect of the annealing on the work-function of $In_2O_3$ films was considered. The work-function obtained from annealed films at $400^{\circ}C$ was 7.0eV. Thus, the annealed $In_2O_3$ films are an alternative to ITO films for use as transparent anodes in OLEDs.

• Atmosphere
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• v.33 no.5
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• pp.477-492
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• 2023

Based on the new climate normals (1991~2020), annual mean, maximum and minimum temperature is 12.5℃, 18.2℃, and 7.7℃, respectively while annual precipitation is 1,331.7 mm, the annual mean wind speed is 2.0 m s^-1, and the relative humidity is 67.8% in the Republic of Korea. Compared to 1981~2010 normal, annual mean temperature increased by 0.2℃, maximum and minimum temperatures increased by 0.3℃, while the amount of precipitation (0.7%) and relative humidity (1.1%) decreased. There was no distinct change in annual mean wind speed. The spatial range of the annual mean temperature in the new normals is large from 7.1 to 16.9℃. Annual precipitation showed a high regional variability, ranging from 787.3 to 2,030.0 mm. The annual mean relative humidity decreased at most weather stations due to the rise in temperature, and the annual mean wind speed did not show any distinct difference between the new and old normals. With the addition of a warmer decade (2011~2020), temperatures all increased consistently and in particular, the increase in the maximum temperature, which had not significantly changed in previous decades, was evident. The increasing trend of annual and summer precipitation by the 2010s has disappeared in the new normals. Among extreme climate indices, MxT30 (Daily maximum temperature ≥ 33℃ days), MnT25 (Daily minimum temperature ≥ 25℃ days), and PH30 (1 hour maximum precipitation ≥ 30 mm days) increased while MnT-10 (Daily minimum temperature < -10℃ days) and W13.9 (Daily maximum wind speed ≥ 13.9 m/s days) decreased at a statistically significant level. It is thought that a detailed study on the different trends of climate elements and extreme climate indices by region should be conducted in the future.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.283-296
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• 2014

The distribution of heavy metals in the stormwater runoffs from industrial sites around Shihwa Lake that implements the total pollutant load management system (TPLMS) was studied to characterize the temporal changes of metal concentrations and to assess the ecological risk in dissolved and particulate phases of the selected metals. The dissolved Co and Ni concentration demonstrated first flush and tended to decrease with increasing of the duration of rainfall. The intensity of precipitation was found to be the main controlling factor of particulate metals in the stromwater runoffs. The particulate concentration of Pb accounted for 97.2% so the particulate phase was its main form. Other metals followed the sequence: Pb>Cu>Cd>Co>Zn>Ni. The particulate-dissolved partitioning coefficient ($K_d$) indicated that the $K_d$ of Pb were bigger than that of other metals because the metal Pb in the stormwater runoffs is quickly removed into the particulate phase. In a single day rainfall event, total runoff fluxes for total metals as the sum of dissolved and particulate forms through only two sewer outlets were 2.21 kg for Co, 30.5 kg for Ni, 278.3 kg for Cu, 398.3 kg for Zn, 0.39 kg for Cd and 40.0 kg for Pb, respectively. Given the annual rainfall, the number of rain days and the basin area for total pollutant load management system (TPLMS) of Shihwa area, enormous amount of non-point metal pollutants were entered into Lake with any treatment. The dissolved metals (e.g., Ni, Cu and Zn) in the stormwater runoffs exceeded the acute water quality criteria. Additionally, all metals were significantly enriched in the particulate phase and exceeded the PEL criteria of sediment quality guidelines (SQGs). These results indicated that the heavy metals in the stormwater runoffs may pose a very high ecological risk to the coastal environments and ecosystem.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.457-464
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• 2017

This study has utilized the stand density management diagram to devise an efficient management standard for the stand density for Pinus densiflora that secures the health of the stands and predicted the harvest goals. The appropriate stand control level was estimated by modeling the relationship of the relative yield index (Ry) to the ratio of slender trees within the stand through an exponential function; the coefficient of determination ($R^2$) was found to be 0.424 according to the estimation. The ratio of slender trees within the stand showed a tendency of rapid increase at a certain relative yield index; with this relational function, the appropriate Ry value of 0.84 was obtained. By estimating the curve of the Ry value 0.84, which was the appropriate stand density management level, as well as the height of dominant trees in the central region of Korea, the production objective for each site index was set. Assuming that the final age by the site indices ranged from 10 to 16 for the P. densiflora in central region of Korea, the number of production was estimated to be between 426 to 1,311 trees per ha. It was predicted that the production of medium-diameter logs larger than 30 cm in diameter is possible for the target DBH at a site index of more than 16; small-diameter logs larger than 20 cm in diameter for site indices 12 and 14 enabled, and small-diameter logs of less than 20 cm for site index 10.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.4
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• pp.196-203
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• 2004

To understand the geochemical processes in the Han River Estuary, distributions and behaviors of nutrients, dissolved organic matters, and uranium were investigated and analyzed during estuarine tidal mixing in June 2000 and February 2001. The distribution of inorganic nutrients showed very dynamic distributional patterns implying an apparent nitrification process and a concave non-conservative mixing along the salinity gradient. Dissolved organic carbon was high in the upstream region and decreased sharply in the low salinity region of around 5 psu. The 3-D fluorescence characteristic of dissolved organic matter showed two distinct fluorophores in the study area. Biomacromolecules originated mainly from the indigenous biochemical processes and geomacromolecules from terrestrial humic materials. In the study area, the distribution of geomacromolecule showed a concave non-conservative property along the salinity gradient presumably due to the flocculation and removal processes in the estuary. Meanwhile, distribution of the dissolved uranium, mainly in the form of stable uranium carbonate complex, also showed a concave non-conservative property along the salinity gradient in the Han River Estuary. From this study, the removal rate of dissolved uranium in the Han River Estuary was estimated to be about 7.1 ton per year.