• Proceedings of the Korean Environmental Sciences Society Conference
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• 2000.05a
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• pp.251-254
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• 2000

In this study, we investigated vertical distribution and seasonal changes of phytophlankton community in the Hae-Dong Reservoir from March 1999 to Feburary 2000. This reservoir is relativly small (surface area, 2.7 $km^2$) and is the source of drinking water supply to the eastern part of Pusan City. Samples were collected at 2 sites (1, 3, and 6 m; site 1, in front of the dam; site 2, inlet). The dominant group was Bacillriophyceae at both sites (over 63%), and other groups exhibited seasonal changes (high cyanobacterial density in summer; green algal communities in winter). Chrysophyceae and Dinophyceae were maintained lower level during the study period. Along the water depth, all classess of phytoplankton did not show distintive vertical distribution at both sites except during the blue-green algal bloom in the middle of July and late September. The phytoplankton community dynamics in the Hoe-Dong Reservoir was strongly affected by the hydrological factors such as concentrated precipitation and short retention time.

• Journal of Ecology and Environment
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• v.35 no.4
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• pp.307-311
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• 2012

This study was conducted to evaluate the dynamics of soil respiration (total soil and heterotrophic respiration) following fertilizer application in red pine forests. Fertilizer (N:P:K = 113:150:37 kg/ha), which reflects current practices in Korean forest, was applied in April 2011, and total soil and heterotrophic respiration rates were monitored from April 2011 to March 2012. Monthly variation of total soil and heterotrophic respiration rates were similar between the fertilizer and control treatments, as soil temperature was the dominant factor controlling the both rates. Total soil respiration rates during the study period were not significantly different between the fertilizer (0.504 g $CO_2\;m^{-2}\;h^{-1}$) and control (0.501 g $CO_2\;m^{-2}\;h^{-1}$) treatments. However, the proportion of heterotrophic respiration was higher in the fertilizer (78% of total soil respiration rates) than in the control (62% of total soil respiration rates) treatments. These results suggest that current fertilizer practices in Korea forest soil do not substantially affect total soil respiration rates.

• Journal of Pharmaceutical Investigation
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• v.21 no.3
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• pp.161-170
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• 1991

The storage stabilities of immunoliposomes incorporated with variable amounts of ganglioside $G_{M1}$ were investigated as a function of time. temperature. and composition by observing absorbance of visible light and calcein release. In the column chromatographe, the layer of unsaturated PE(dioleoylphosphatidylethanolamine : DOPE). unable to form stable liposomes at physiological temperature and pH, were formed when palmitoyl-immunoglobulin G(IgG) $(2.5{\times}10^{-4}\;mol/DOPE\;mol)$ added. The incorporation of ganglioside $G_{M1}$ into immunoliposome. enhanced the stabilities of bilayers during the extended period of storage. The turbidities of immunoliposomes coated with ganglioside $G_{M1}$ exhibited the maximum near 20 mol% $G_{M1}/DOPE$ mol. probably because of the disturbance of the bilayer characteristics, i.e., layer transition or reorientation of interaction sites. At low temperature. the higher stability was achieved than at elevated temperatures. After one week of storage. the redispersed liposomal solutions at lower temperatures maintained the original elution patterns in chromatography but broader distribution at elevated temperatures. During the storage, it is suggested the aggregation is the more dominant phenomena for liposomes kept at $5^{\circ}C$ than the fusion. while he fusion is at elevated temperatures.

• Journal of Astronomy and Space Sciences
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• v.28 no.2
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• pp.103-108
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• 2011

The latitudinal variation of sunspots appearing during the period from 1874 to 2009 has been studied in terms of centerof-latitude (COL). The butterfly diagram has been used to study the evolution of the magnetic field and the dynamics at the bottom of the solar convection zone. Short-term periodicities have been of particular interest, in that they are somehow related to the structure and dynamics of the solar interior. We thus have focused our investigation on shortterm periodicities. We first calculated COL by averaging the latitude of sunspots with the weight function in area. Then, we analyzed the time series of COL using the wavelet transform technique. We found that a periodicity of ~5 years is the most dominant feature in the time series of COL, with the exception of the ~11 year solar cycle itself. This periodicity can be easily understood by considering small humps between the minima in the area-weighted butterfly diagram. However, we find that periodicities of ~1.3 (0.064), ~1.5 (0.056), or ~1.8 (0.046) years ($\frac{1}{month}$), month ), which have been previously suggested as evidence of links between the changing structure of the sunspot zone and the tachocline rotation rate oscillations, are insignificant and inconsistent. We therefore conclude that the only existing short-term periodicity is of ~5 years, and that periodicities of ~1.3, ~1.5, or ~1.8 years are likely to be artifacts due to random noise of small sunspots.

• Ocean and Polar Research
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• v.24 no.4
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• pp.331-343
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• 2002

The southern tidal flat of Kanghwa Island with an area of approximately $90km^2$ is one of the biggest flats on the west coast of Korea. Surface sediments for sedimentary analyses were sampled at 83 stations in August 1997, September 1999 and August 2000. The very poorly-sorted mud sediments were predominant in the eastern part of the tidal flat, whereas the poorly-sorted sand-mud mixed sediments were dominant in the western part. The area of muddy sediment distribution diminished, but that of sandy mud sediment extended to southeastward tidal flat for three years. In the western part of tidal flat, deposition occurred during the period of spring to summer, whereas erosion occurred in winter. Sediment accumulation rates during three years indicated that the sediments deposited continuously in the eastern part of tidal flat, whereas eroded in the western part of tidal flat. Recently, construction of artificial structures such as new airport, island-connecting bridges and dikes near the tidal flat might change tidal current and river flow pattern. In order to reduce the ecological damage and to preserve tidal-flat environment, it is necessary to Investigate long-term impacts on sedimentary environment and ecology.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.3
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• pp.136-145
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• 2002

Monitoring data from agricultural reservoirs throughout the country were analyzed to evaluate the limiting factor fur algal growth and relationships between Chl-a, total phosphorus (TP), and total nitrogen (TN). Total 394 reservoirs ranging from below 500 ㎥ to over 50 million ㎥ in storage volume were monitored from 1990 to 2000 with respect to TP, W, Chl-a, and their annual mean values were used fur the analysis. Based on N/P ratio, the dominant limiting factor for algal growth was turned out to be phosphorus in agricultural reservoirs (about 83%). Therefore, the proper managements of phosphorus in the agricultural watershed appear to be crucial to prevent excessive on algal growth. The effects of phosphorus and nitrogen ware most eminent during the summer period. And the effect of nutrients on the algal biomass (Chl-a) development appeared to be greater in smaller the reservoirs than in larger ones. Generally, Chl-a and TP demonstrated a close relationship while that of Chl-a and TN showed less correlationship. Chl-a and chemical oxygen demand (COD) also showed a good relationship. Beth ratios of Chl-a / TP and Chl-a / COD relationships were within the range of literature values. Quantitative analysis of TP and COD is relatively convenient compared to that of Chl-a, and the relationship between TP and COD and Chl-a from this study could be used beneficially for water quality management of agricultural reservoirs and related water quality modeling.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.535-539
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• 2002

Incontinentia pigmenti is a rare neurocutaneous syndrome characterized by vesiculobullous skin disease in neonates and infants, a noninfectious disease that should be distinguished from infectious diseases with the neonatal seizure or encephalopathy. This disease is X-linked dominant with Xq28 region abnormalities and often associated with developmental defects of the ocular, skeletal, dental, and central nervous system. Central nervous system involvement in the neonatal period, or complicated by encephalopathy, may cause severe neurologic impairment, retardation or even death. We experienced a case of incontinentia pigmenti in a three-day-old female patient who had characteristic papulovesicular skin lesions and partial seizures with secondary generalization. Histopathological examination favored the diagnosis of incontinentia pigmenti and a brain MRI showed undifferentiated white matters with periventricular nodular lesions.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.4
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• pp.297-303
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• 2002

Fine particles (d$_{p}$ < 2.5 $\mu$m) were measured using an annular denuder system (ADS) in Chongju. The data set was collected on fifty-eight different days with a 24-hr sampling period from October 27, 1995 through August 25, 1996. Particulate nitrate in the ADS was also measured on teflon and nylon filters in series behind denuders to collect HNO$_3$, HNO$_2$, SO$_2$and NH$_3$. From this study. the mean concentration of particulate nitrate of PM$_{2.5}$ in the ADS were seen with the following order: winter (5.05) ＞fall (4.36) ＞spring (3.92) > summer (1.10 $\mu\textrm{g}$/㎥). Nitrate losses, which calculated from the ratio of nylon filter nitrate to the sum of teflon and nylon filter nitrates, varied in the following manner summer (72.2%) > spring (42.6%) > fall (23.5%)> winter (0.4%). Especially, gaseous nitric acid was dominant at temperature higher than 8$^{\circ}C$ while particulate nitrate was major species in total nitrate below that temperature. This indicates the particulate nitrate loss is strongly correlated rather with ambient temperature.e.e.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.917-922
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• 2013

Changes in fishing ground of the large pair trawler were investigated by year, month and species off Korean waters. We used catch data by sea-block lat.${\times}$long.:$30^{\prime}{\times}30$) of the National Fisheries Research and Development Institute (NFRDI) and monthly fishing production statistics of Korean statistic information service from 1990 to 2007. In the 1990s, the demersal fish like Larimichthys polyactis, Collichthys sp, Portunus trituberculatus and Muraenesox cinereus were the dominant species, and in the 2000s, they were changed from demersal fish into pelagic fish like Scomberomorus niphonius, Scomber japonicus, Engraulis japonicus and Todarodes pacificus. Species composition of catch showed temporal variation by cluster analysis deviding into 4 period, 1990-1994, 1995-2000, 2001-2003 and 2004-2007. Fishing ground in the 2000s was decreased up to 2/3 in the 1990s, while the density of catch in the fishing ground in 2000s was higher than the 1990s.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.319-325
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• 2017

Marine algal flora and community structures were examined seasonally at three sites around the Shingori Nuclear Power Plant, Korea from February to November 2016. A total of 76 species were identified, including 9 green, 14 brown and 53 red algae. The greatest number of species occurred at Daesongri (51 species) followed by Sinamri (43 species) and at the discharge area (38 species) during the study period. Of the 76 seaweeds, 59 annuals and 17 warm tolerant species were recorded. Annual average biomass in dry weight varied from $168.02g/m^2$ at the discharge area to $222.53g/m^2$ at Sinamri. The coarsely branched form was the dominant functional form of seaweeds at the three sites. Seaweed community structures at the discharge site were distinguishable by decreasing species richness, biomass, species diversity index, richness index, and evenness index. The ratio of warm tolerance species and the dominance index values were remarkably higher at the discharge than those at the other sites.