• 한국해양학회지
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• v.28 no.3
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• pp.186-191
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• 1993

Scrippsiella trochoidea is a dinoflagellate responsible for red tide in early spring in southern coastal water. Marine bacteria appear to exert critical roles on the development and decay of phytoplankton bloom in marine ecosystem. It is likely that marine bacteria, Pseudomonas spp., share some metabolic processes with S. trochoidea. To investigate interactions between S. trochoidea and Pseudomonas spp. directly, cysts of S. trochoidea isolated from the bottom mud in Masan Bay have been germinated and cultured. From the S. trochoidea cultured medium, we have isolated Pseudomonas spp., a dominant and cultured. From the S. trochoidea cultured medium, we have isolated Pseudomonas spp., a dominant species. Both of Pseudomonas spp. and S trochoidea have been simultaneously inoculated into the sterilized sea water and cultured to examine the change of fatty acids. The major fatty acids that showed increases in composition during the dispecific culture were $C_{18:0/},{\;}C_{20:5}{\;}and{\;}C_{22:5}$ in S. trochoidea, and in Pseudomonas spp. Especially, $C_{20:5}{\;}and{\;}C_{18:0}$ were increased in S. trochoidea but decreased in Pseudomonas spp. These results strongly suggest that two species share some processes in their fatty acid metabolism.

• Journal of Sericultural and Entomological Science
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• v.10
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• pp.45-52
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• 1969

This experiment was carried out to investigate the factors causing obstructions to the productivity of mulberry field on slope land, increasing the productivity of that, in Korea. These results are summerized as follows: 1. Poor fertilization and unreasonable management due to overbalance of mulberry field in scale were proved to be most important factors of them obstructing the growth of mulberry. Therefore, it is necessary to increase the amount of fertilizer and cultivate mulberry fold in reasonable scale for the development of productivity. 2. As the direction of mulberry fold on slope land are closely related to the productivity, mulberry cultivation of the eastern or southern exposure were suitable, but that of northern not. It seemed to show no difference between the cultivation in 20 degree slope land and in less than that, 300 m above sea level and below that level. 3. A depth of top soil should be more than 60 cm. 4. Rosang in varieties of mulberry tree is not suitable but Chuwoo is comparatively suitable in slope land. 5. The number of mulberry trees in planting must be more than 900 trees per 10 ares.

• Journal of architectural history
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• v.9 no.1 s.22
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• pp.27-46
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• 2000

This study aims at examining the background and development process of Masan city after Koryo Dynasty, making a reconstructive map of Original Masan using the first registration maps made in 1912 and analyzing the urban structure of the Original Masan area. The origin of Masan city went back to Koryo dynasty. Around 1040 Koryo government placed an official shipping facility in Masan to transport the taxed grain to the capital city. After that Masan became an important port covering the southern part of KyungSang-Do. And the urbanization of the Original Masan began to bud after a shipping facility was again established by the Chosun Dynasty in 1760 and strengthened in the 19th century after the social standing system was broken and many peasants moved to cities as daily workers. In 1899 Masan was forced to be opened to foreign powers and they placed an international settlement distanced from the area(Original Masan). After this many Japanese advanced to the international settlement and further to the area. The advancement of Japanese brought a critical change in the urban structure of the area. Land was owned by Japanese and many modern sysytems were introduced such as modern buildings, new roads, railroad and modern factories. According to the reconstructive map of the area, 80.5% of land lots are less than $200m^2$ showing the size of each land lot is comparatively small. And Japanese occupied 31.5% of the land in the area. Their land was located on the stratigic points near the port and the center of commerce. The ratio of the road area to the whole land was around 14%, not so low for urban areas in that time. The reconstructive map reveals the exact coastline of the year 1912 erased now due to filling the sea and extending the land, Present Masan city has been developed having the Original Masan as its nucleus. The area has been always the center of urban activities for Masan city. Making an exact reconstructive map for the area and analyzing the urban structure of the area in 1912 is a very important work to understand Masan city wholy.

• Journal of Environmental Science International
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• v.25 no.1
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• pp.85-97
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• 2016

A comparison of ozone simulations in the seoul metropolitan region (SMR) using the community multiscale air quality (CMAQ) model with SAPRC99 and CB05 chemical mechanisms (i.e. EXP-SP99 and EXP-CB05) has been conducted during four seasons of 2012. The model results showed that the differences in average ozone concentrations between the EXP-SP99 and EXP-CB05 were found to be large in summer, but very small in the other seasons. This can be attributed that the SAPRC99 tends to produce more ozone than the CB05 in urban area like the SMR with low VOC/NOx ratio under high ozone conditions. Through quantitative comparison between two mechanisms for the summer, it was found that the average ozone concentrations from the EXP-SP99 were about 3 ppb higher than those from the EXP-CB05 and agreed well with the observations. Horizontal differences in ozone concentrations between SAPRC99 and CB05 showed that significant differences were found in southern part of the SMR and over the sea near the coast in summer.

• ALGAE
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• v.17 no.1
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• pp.11-19
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• 2002

Twenty-nine culture strains belonging to the genus Alexandrium Halim (Dinophyceae) were established from water column or sediments in Korea. Seventeen isolates were identified as A. tamarense (Lebour) Balech, eight isolates as A. sp. cf. catenella and one as A. catenella (Whedon et Kofoid) Balech according to the presence or absence of a ventral pore, the shape of the posterior sulcal plate and the sulcal width. Three isolates were unable to be identified due to considerable distortion of thecal plates and lack of enough materials, but typical of A. tamarense and/or A. catenella. The overall cell shape of A. tamarense was usually longer than wide. The posterior sulcal plate was definitely longer than wide dorsoventrally, and sulcus extended posteriorly without apparent widening. They were distributed in three major coasts of Korea. In contrast, the cell shape of A. sp.cf. catenella was generally anterior-posteriorly flattened. The transversal axis of the posterior sulcal plate was always longer than the longitudinal, or both axes were nearly equal in length. Its sulcus was broader than that of A. tamarense and widened in the direction of antapex about 1.5 times. This morphotype existed in nearshore and offshore waters of the southern Korea sea. One of A. catenella isolates from Jinhae Bay showed no conspicuous differences with A. sp. cf. catenella except for the consistent absence of a ventral pore.

• ALGAE
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• v.18 no.1
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• pp.49-58
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• 2003

The short-term dynamics of the summer phytoplankton community structure were investigated in coastal waters around Namhae Island, the Southern Sea of Korea. The study was based on a comprehensive survey constituting 39 collections from 13 stations on July 18-22, August 1-2, 14-16 and 27-30, respectively. The community structure was analysed using cluster analysis and important environmental correlates of the assemblage structure were identified with canonical correspondence analysis (CCA). Water temperature, salinity, NO₂, NO₃, NH₄, PO₄, chlorophyll a and transparency were measured as physico-chemical environmental factors which may be associated with the phytoplankton community structure. Variations of salinity and concentrations of NO₃ and chlorophyll a were not significant. In addition to warmer water temperature, concentrations of NO₂, NO₄and PO₄ decreased at the beginning of August. And transparency was deeper and water column became very unstable after the middle of August. A wide taxonomic diversity was encountered during the survey, including a total of 121 taxa which was composed of 72 diatoms, 48 dinoflagellates and 1 euglenoid species. Cluster analysis showed that the Phytoplankton community could be divided into 4 distinct groups, indicating rapid changes of the community in the short course of this survey. These phytoplankton groups also showed distinctive dispersion patterns in 2-dimensional canonical space, indicating distinct groupings for stations at each survey. Dominant taxa of diatoms (Chaetoceros curvisetus, Chaetoceros spp., Leptocylindrus danicus, Leptocylindrus mediteraneus, Skeletonema costanum, and Pseudo-nitzschia pungen) clustered in region of CCA space corresponding to stations surveyed at the middle of July. Dominant taxa of dinoflagellates were tightly associated with stations surveyed at the middle (Karenia breve) and end (Cochlodinium polykrikoides and Polykrikos schwartzii) of August. The CCA also showed that the phytoplankton community compositions were highly associated with water temperature, transparency, NO₂, NH₄ and PO₄, suggesting that gradients in physical and nutrient conditions affect short-term changes in phytoplankton composition.

• Ocean and Polar Research
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• v.34 no.1
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• pp.53-64
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• 2012

In order to understand the relationship between the formation of hypoxia sediment by eutrophication and changes in benthic foraminiferal assemblage, micropaleontological and geochemical analyses were carried out on one sediment box core (K-1) recovered in the northern Gamak Bay, which is one of the aquacultural areas in the South Sea of Korea. In this analysis, the PON content in the sediment rapidly increased, while the C/N ratio and the C/S ratio decreased since 1977. These results indicate that eutrophication commenced in 1977 in the northern Gamak Bay, and consequently, the hypoxia sediment is 20 cm thick. Ammonia beccarii-Buccella frigida assemblage occurs before the formation of hypoxia sediment. Trochammina hadai-Buccella frigida assemblage appeared in the transitional period toward hypoxia and Trochammina hadai assemblage with a low abundance and diversity is observed in the hypoxia sediment. The agglutinated species T. hadai is regarded as a bio-indicator (opportunistic species) of the organic pollution in northern Gamak Bay.

• ALGAE
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• v.24 no.3
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• pp.139-147
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• 2009

Microalgae using a submersible fluorescence probe in water column (up to 100 m) were measured during the austral summer of 2006 (February) in Prydz Bay, East Antarctica (triangular-shaped embayment in the Indian sector of Southern Ocean). Concurrently, environmental parameters such as temperature, salinity and nitrogen (nitrate, ammonium, urea) uptake rates were measured. The concentration of phytoplankton is relatively high due to availability of high nutrients and low sea surface temperature. Phytoplankton community is dominated by diatoms whereas cryptophytes are in low concentration. The maximum concentration of total chlorophyll is 14.87 ${\mu}g\;L^{-1}$ and is attributed to upwelled subsurface winter water due to local wind forcing, availability of micro-nutrients and increased attenuation of photosynthetically available radiation (PAR). Concentration of blue-green algae is low compared to that of green algae because of low temperature. Comparatively high concentration of yellow substances is due to the influence of Antarctic melt-water whereas cryptophytes are low due to high salinity and mixed water column. Varied concentrations of phytoplankton at different times of Fluoroprobe measurements suggest that the coastal waters of Prydz Bay are influenced by changing sub-surface water temperature and salinity due to subsurface upwelling induced by local winds as also melting/freezing processes in late summer. The productivity is high in coastal water due to the input of macro as well as micro-nutrients.

• Atmosphere
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• v.18 no.4
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• pp.387-395
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• 2008

The impact of horizontal resolution on a regional climate model was investigated by simulating precipitation over the Korean Peninsula. As a regional climate model, the SNURCM(Seoul National University Regional Climate Model) has 21 sigma layers and includes the NCAR CLM(National Center for Atmospheric Research Community Land Model) for land-surface model, the Grell scheme for cumulus convection, the Simple Ice scheme for explicit moisture, and the MRF(Medium-Range Forecast) scheme for PBL(Planetary Boundary Layer) processing. The SNURCM was performed with 20 km resolution for Korea and 60 km resolution for East Asia during a 20-year period (1980-1999). Although the SNURCM systematically underestimated precipitation over the Korean Peninsula, the increase of model resolution simulated more precipitation in the southern region of the Korean Peninsula, and a more accurate distribution of precipitation by reflecting the effect of topography. The increase of precipitation was produced by more detailed terrain data which has a 10 minute terrain in the 20 km resolution model compared to the 30 minute terrain in the 60 km resolution model. The increase in model resolution and more detailed terrain data played an important role in generating more precipitation over the Korean Peninsula. While the high resolution model with the same terrain data resulted in increasing of precipitation over the Korean Peninsula including the adjoining sea, the difference of the terrain data resolution only influenced the precipitation distribution of the mountainous area by increasing the amount of non-convective rain. In conclusion, the regional climate model (SNURCM) with higher resolution simulated more precipitation over the Korean Peninsula by reducing the systematic underestimation of precipitation over the Korean Peninsula.

• Ocean and Polar Research
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• v.24 no.3
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• pp.267-278
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• 2002

This study investigated the spatial characteristics of warming trends and the dipole-like pattern of temperature field in the Antarctic Peninsula using surface air temperature (SAT) of 10 stations in the vicinity of the Antarctic Peninsula. SAT data for the 1962-2001 period at 6 stations (Rothera, Faraday/Vernadsky, Bellingshausen, Orcadas, Esperanza, Halley) revealed in general the larger warming trends in autumn and winter except for Halley. The largest warming was shown for August in the west side of the Peninsula (more than $0.9^{\circ}C/decade$). On the other hand, the recent 14-year SAT data showed the strong warming trends at 9 stations except for Halley in the earlier period (April-June) than August for the 1962-2001 period. The largest warming appeared in May at Esperanza and Butler Island. SAT of the two sides showed significant positive correlations over most of the period except for the mid- and the late 1970s, in which significant negative correlations were found. In the correlation analysis between SAT and sea surface temperature (SST) anomalies in the NINO 3.4 region, strong negative correlation was found in the west side of the Peninsula. Details of the correlation analysis exhibited that the negative correlation was significantly strong from the early 1980s to the mid-1990s. However, it was difficult to find significant correlations of ENSO with SAT in the east side of the Peninsula. So, in this study it failed to find out clearly the out-of-phase relationship of SAT across the Antarctic Peninsula.