• Korean Journal of Microbiology
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• v.11 no.2
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• pp.89-100
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• 1973

Dextrinogenic and saccharogenic amylase activities of Rhizopus isolated from various substrates collected throughout South Korea are measured, and their amylase activities are surveyed from taxnomical, ecological, and physiological viewpoints. Among the 151 strains of Rhizopus, strain number 49 exhibiting most prominent saccharogenic amylase activity is selected as a best strain, and strain number 17 is selected as a best strain for dextrinogenic amylase activity. Amylase activities of Rhizopus are so variable in different strains even in the same species. In general, however, R. japonicus, R. liquefaciens, and R. shanghaiensis show high saccharogenic amylase activities, and R.chiuniang, R.achlamydosporus, and R.bahrnensis show high dextrinogenic amylase activities, while R.nigricans exhibits lower activities for both amylase. The strains isolated from kneaded cereals, such as "meju" and "kockja", exhibited very strong dextrinogenic and saccharogenic amylase activities as compared with the strains isolated from other sunstrates. The mean value of dextrinogenic amylase activities of the strains from southern inland region and saccharogenic amylase activities of the strains from middle coast region are, more or less, higher than those of the strains from the other regions. In the culture at 30.deg.C, those strains which exhibit better mycelial and air mycelial growth than sporangial formation show very high dextrinogenic and saccharogenic amylase activities. amylase activities.

• Journal of Ecology and Environment
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• v.46 no.3
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• pp.259-272
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• 2022

Background: The Korean Peninsula exhibits a characteristic graded floral distribution, with northern (Manchurian flora) and southern (China-Japan-Korea flora) lineage species coexisting according to climatic and topographical characteristics. However, this distribution has been altered by climate change. To identify ecosystem changes caused by climate change and develop appropriate measures, the current ecological status of the entire Korean Peninsula should first be determined; however, analysis of the current floral distribution in North Korea has been hampered for political reasons. To overcome these limitations, this study constructed a database of floral distributions in both South and North Korea by integrating spatial information from the previously established National Ecological Survey in South Korea and geocoding data from the literature on biological distributions published in North Korea. It was then applied to analyze the current status and distribution characteristics of Manchurian and China-Japan-Korea plant species on the Korean Peninsula. Results: In total, 45,877 cases were included in the Manchurian and China-Japan-Korea floral distribution database. China-Japan-Korea species were densely distributed on Jeju-do and along the southern coast of the Korean Peninsula. The distribution density decreased as the latitude increased, and the distributions reached higher-latitude regions in the coastal areas compared with the inland regions. Manchurian species were distributed throughout North Korea, while they were densely distributed in the refugia formed in the high-elevation mountain regions and the Baekdudaegan in South Korea. In the current distribution of biomes classified according to the Whittaker method, subtropical and endemic species were densely distributed in temperate seasonal forest and woodland/shrubland biomes, whereas boreal species were densely distributed in the boreal forest biome Korean Peninsula, with a characteristic gradation of certain species distributed in the temperate seasonal forest biome. Factor analysis showed that temperature and latitude were the main factors influencing the distribution of flora on the Korean Peninsula. Conclusions: The findings reported herein on the current floral distribution trends across the entire Korean Peninsula will prove valuable got mitigating the ecological disturbances caused by ongoing climate change. Additionally, the gathered flora data will serve as a basis for various follow-up studies on climate change.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.897-904
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• 2006

The eastern coast of northeastern Brazil (NEB), a coastal land-strip up to 300 km wide and stretching out from Rio Grande do Norte $(5^{\circ}S)$ State down to the south of Bahia State $(17^{\circ}S)$, experiences different rain producing systems, such as distrubances in the south-east trade winds, frontal systems penetration, land-sea breeze circulation and local convection associated with the topography and moisture flux convergence. The annual total rainfall ranges from 600 inland to 3000 mm on the coast. Rainfall totals 5 to 12 times the focal climatic means were recorded in various regions of Alagoas state in January 2004. It was estimated that 46,000 people were homeless, with material damages exceeding US$10 million as a consequence of the ensuing floods. GOES infrared images analysis showed that the main weather system responsible for this anomalously high rainfall totals was an Upper Troposphere Cyclonic Vortex (UTCV), which formed at about a $27^{\underline{\circ}}W\;e\;12^{\underline{\circ}}S$ and remained active for the entire month of January over NEB.

• Journal of The Geomorphological Association of Korea
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• v.24 no.3
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• pp.133-147
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• 2017

This study investigated the cases of relative location, especially focused on the geomorphological situation, for the conceptualization of the location knowledge. In order to perform this study, first of all, I approached meaning of location. In this study I used the terms 'site' and 'situation'. 'Site' as used here means the location of a given place with its local internal features or resources. 'Situation' refers to the location of place as related to other places. As to location, no place exists in isolation. Therefore, it is necessary to look beyond the internal nature of the area itself to perceive its external relations with other areas. The examples of geomorphological situation were focused on the scale linkage of the examples, the interaction between elements of earth surface processes, and the method of comparative region. The regions of examples were the landscape of Mt. Hymalaya to Bengal deep sea fan, the climatical difference of continental east and west, the landscape of Mt. Geum & Sangju beach, the landscape of the south and north face of Mt. Mai., Hamjibaakgol asymmetrical valley, and the landscape of inland sea and outer sea type island.

• Journal of Environmental Science International
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• v.30 no.9
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• pp.753-762
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• 2021

This study analyzed the characteristics of strong winds accompanying typhoons for a period of 116 years, from 1904 to 2019, when modern weather observations began in Korea. Analysis shows that the average wind speed and high wind rate caused by typhoons were higher over the sea and in the coastal areas than in the inland areas. The average wind speed was higher over the West Sea than over the South Sea, but the rate of strong wind was greater over the South Sea than over the West Sea. The average wind speed decreased by 1980 and recently increased, while the rate of strong winds decreased by 1985 and has subsequently increased. By season, the strong winds in autumn (september and october) were stronger than those in summer (june, july, and august). Strong winds were also more frequent in autumn than in summer. The analysis of the changes in strong winds caused by typhoons since the 1960s shows that the speed of strong winds in august, september, and october has increased more recently than in the past four cycles. In particular, the increase in wind speed was evident in fall (september and october). Analysis of the results suggests that the stronger wind is due to the effects of autumn typhoons, and the increased possibility of strong winds.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.1
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• pp.55-64
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• 2005

Spatio-temporal variations of phytoplankton abundance and nutrient concentrations were investigated in the Namdaechon estuary, Yangyang, from April to December, 2003. A total of 51 phytoplankton species were identified with 32 diatom species in the study area. Phytoplankton abundance ranged from 14 cells/mL to 3,798 cells/mL. Small sized benthic and pennate-type diatoms like Cymbella spp., Fragilaria spp., Navicula spp., Synedra spp. were dominant at throughout the whole study area. Various planktonic species like Chlamydomonas sp., Peridinium spp., Euglena spp., Cryptomonas spp. etc. were abundant especially at the estuary of the Namdaechon, from May to August. Phytoplankton bloom (>3,000 \;cells/mL) occurred from the late May to mid June. After September when the sandbank of estuary was broken by the typhoon 'Maemi', planktonic species disappeared. These planktonic species were followed by oceanic diatoms, Skeletonema costatum and Chaetoceros spp.. Concentrations of dissolved inorganic nitrogen (DIN) and silicate were relatively high at the upstream in summer. In May, before phytoplankton bloom, high concentrations of phosphate $(>3.5\;{\mu}mol/L)$ were observed at all the study area. These results suggested that spatio-temporal variation of phytoplankton in the Namdaechon estuary was related to formation of sandbank at the mouth of the estuary, fluid speed affected by sandbank and nutrients supplied in spring. High correlation $(r^2=0.928)$ between chlorophyll a and biological oxygen demand (BOD) implies that BOD was related to phytoplankton abundance in the Namdaechon estuary.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.459-476
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• 1993

Vegetational structure and successional sere were investigated for the evergreen and nearby deciduous broad-leaved forests in inland areas (Turyunsan, Pulgapsan) and south- western island areas (Hongdo, Chindo). The evergreen broad-leaved forests of the four areas showed a sera1 stage with an age structure mostly under fifty years old. Dominant evergreen broad-leaved species in canopy layer were Castanopsis cuspidata var. sieboldii, Machilus thunbergii, Quercus acuta, Q. stenophylla, Q. glauca, and Ncolitsea serzceu. Succession of the forest vegetation in the surveyed areas was proceeding from deciduous broad-leaved trees to evergreen broad-leaved trees. The species of climax stage were assumed to be Machilus thunbergii, iVeolitseu sericea and Dendropanax morbifera in canopy layer, Aucuba japonica and Machilus japonica in subtree and shrub layer.

• Economic and Environmental Geology
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• v.30 no.6
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• pp.531-541
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• 1997

Unconsolidated sediments of Youngjong Island were investigated to consider the vertical distribution of clay minerals and their origin. At least three sedimentation units can be recognized by color, magnetic susceptibility, and pH. X-ray diffraction analysis of clay size fraction reveals that illite is the most abundant phase (52.06%), and chlorite (27.16%), kaolinite (16.92%), smectite (3.86%) occur next to it. Detailed XRD study suggests that illitic materials contain fairly large amount of ordinary muscovite derived from the mica schist in Youngjong Island and adjacent area. The relative amount of kaolinite and chlorite is less than those of samples from estuary mouth of several rivers that flow to Yellow Sea and South Sea. Especially smectite content of the present sample is much higher than those of estuary sediments. These indicate that the unconsolidated sediments of tidal-flat deposit in Youngjong Island are largely affected by marine influence and partly affected by sediment in influx from China. However, some degree of source of this unconsolidated sediments is inland origin from adjacent estuary sediment and in situ or nearby weathered materials.

• Journal of the Korean association of regional geographers
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• v.12 no.4
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• pp.461-474
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• 2006

This paper aims to analyze regional characteristics of unusual temperature events on summer and winter. The major data used in this study are the daily mean temperature of summer (June-August) and winter (December-February) and wind field on 850 hPa height. Regions of unusual temperature are divided into five regions by the monthly frequency of unusual temperature occurrence. The divided regions are following as: the middle east coastal region (I) where the summer unusual high temperature occurrence frequency is highest; the Gyunggi west coastal and northern middle inland region (II) where winter unusual low temperature occurrence frequency is highest and winter unusual high temperature occurrence frequency is low; the western middle and south region (III) where unusual temperature occurrence ratio is not concentrated on specific season; the forest and southern east region (IV) where unusual high temperature is low; and the south coastal and Jeju island region (V) where winter unusual high temperature is highest.

• Journal of Korean Port Research
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• v.7 no.1
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• pp.43-58
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• 1993

There has been fast progress in economy in Korea derived by a consecutive five-year plan program for economic development started in the early 1960's. In the field of transportation, rapid changes in the technological environment of transportation and communication have brought a revolution of the transport system, of which inter-modal transportation through containerisation is typical. Because of the rapidly growing traffic volumes of cargo, especially container traffic, and lack of investment into transport infrastructure in the past, both road and railway are beyond their capacity. As a result, the public-road network has suffered a serious congestion problem. For instance, in relation to the corridor between Seoul and Pusan, today, it takes about 14 hours for the journey of container trailer through Kyongbu Expressway, for which it used to take only 7 hours in 1986. For the railway, though the congestion problem is not very serious compared with the road sector, a shortage of capacity on certain main lines has emerged as a problem as railway traffic has increased. Furthermore, the further expansion of the system in near future is difficult due to burden of higher construction the cost. Unlike these two modes, coastal shipping, which has been paid relatively less attention for commodity transport in Korea, shows no constraint in this respect. In addition, it is the most cost efficient mode of transport. This work therefore aims to make a proposal for the alternative inland transportation mode, which is to promote the coastal transport of container. Three obstructing factors for the promotion of the coastal transport are investigated and some solutions for those are suggested as follows : First, it appears to be essential to provide exclusive ports for the coastal shipping, that comply with simplification, specialization and rationalization. The optimum size of berths on the exclusive ports in Pusan port is estimated as 16-20. We found that it needs periodical study and publicity on the advantages from the adoption of the coastal mode. Inducing competition in the coastal shipping market is also necessary. For the supply of the fleet in the coastal shipping, chartering of the surplus ships in the oversea shipping is found to be more desirable than new shipbuilding. Second, to solve the fragmentation of the companies which wish to participate in the coastal transport, government has to implement the subsidy policy. The encouragement of participation of the shipping lines engaging in Korea-Japan run and Korea-East South Asia run, into coastal shipping also needs to be considered cautiously. Third, simplification of the document for entry in ports is needed for rational coastal shipping management. We can use B/L (Bill of Lading) for coastal shipping as a prerequisite to get the indemnity by P & I Club. The reduction of the government controls on entering and leaving the ports also needs.