• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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• pp.306-316
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• 2003

We conducted a time-series analysis of temperature and salinity of sea water around Jeju Island, Korea. Monthly mean temperature and salinity was influenced by precipitation and weather conditions on Jeju as well as by oceanographic conditions of the open sea such as the Tsushima Warm Current and sea water in coastal areas. Salinity of Jeju coastal waters was the highest in April, and it was always over 34.00 psu with tiny fluctuation between December and June. Due to the effects of the Tsushima Warm Current, Jeju coastal waters maintained high salinity and stability. Low salinity and its large fluctuations during summer were closely associated with the China Coastal Water and precipitation in Jeju. The place of the lowest water temperature was the northeast coasts of Jeju (Gimneong, Hado, Jongdalri). In winter, as warmer water of the Tsushima Warm Current appeared in western area of Jeju dwindled flowing along the northern coasts of Jeju area and becoming cool, the lowest water temperature often appeared locally in Gimnyeong and its vicinitly in summer. The Tsushima Warm Current flows into the east entrance of Jeju Strait, but its influence is weak because of geometry and strong vertical mixing due to fast tidal currents.

• Ocean and Polar Research
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• v.34 no.2
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• pp.219-228
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• 2012

Tintinnid species distribution has been monitored in the northern East China Sea (ECS) in the summer of 2006 through 2011. This is used to understand the water mass movements in the northern ECS. The warm oceanic tintinnid species had largely spread in 2007 in the area, indicating that there was greater warm water extension into the northern ECS. However the extension of neritic water within the Changjiang diluted water mass has strengthened in 2008 and 2010 because the neritic species distribution had relatively grown in both years. These annual results based on the biological indicators of tintinnid species are well matched with the salinity change in the area. The warm oceanic species, Dadayiella ganymedes had frequently occurred over the study years and had shown a significant relationship with the salinity change. This is valuable as a key stone species for monitoring the intrusion of the Kuroshio within the northern ECS. Information from tintinnid biological indicators can support physical oceanography data to confirm ambiguous water mass properties.

• Journal of Environmental Science International
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• v.15 no.10
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• pp.989-995
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• 2006

Using the principal component analysis and clustering Forest resources are consistently necessary in the future. It takes much time to produce and breed them. However it is difficult to do due to recent social situation. Considering global environment, forest policy should be considered as a global scale rather than a regional one. At least, the policy needs a national scale concern. In order to support forestry, elementary data are needed. In this study, forest characteristics in Ishigawa-gen province have been analyzed through main component analysis and clustering. The results are shown in fig.5 and fig.6.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.299-304
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• 1983

A tongue-like warm water which is a part of the Tsushima Warm Current appears whole year around in the east entrance of the Jeju Strait. Because of this warm water, the current direction flowing into the Jeju Strait from its west area seems to be changed in the Jeju Strait. Therefore the intermediate and bottom water of the Jeju Strait may greatly influence the formation of the coastal water in the South Coast of Korea. Since this tongue-like warm water is stronger in winter than in summer in its formation, Tsushima Warm Current comes closer to the South Coast of Korea in winter and its north boundary frequently approaches close to the coast of Geomun Island and Sori Island.

• 한국해양학회지
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• v.27 no.4
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• pp.259-267
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• 1992

A survey of CTD casting was taken in April 1991 in the eastern Yellow Sea. The vertical structure of water column consists of the upper mixed warm, the mid cold and the lower warm layers devised clearly by a seasonal thermocline and the temperature inversion. A strongest temperature inversion is found in the southern part of the survey area. Where the low-layer water is $3^{\circ}C$ higher than the mid-layer water. The area of the temperature inversion covers about $100{\;}km{\;}{\times}{\;}100{\;}km$ and it is observed 1.5 month later. The temperature and salinity of the low-layer water shows a core structure in vertical sections and the tongue-like distribution extending from the south to the north, implying that the warm and saline water found in the oceanic front south of the survey area in early spring is advocated to the north over 150 km underneath the Yellow Sea cold water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.148-158
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• 2004

In the adjacent seas of Cheju Island, the oceanographic conditions show low salinity surface waters starting in May. This water flows from the southeast part of the China Coastal Water, which flows southeastward along the Great Yangtze Sand Bank until April, with the help of southeasterly winds and flows from the adjacent sea off Cheju Island. In May, the Tsushima Warm Current and the low salinity surface water fluctuate in short and long-term periods as influenced by Yellow Sea Cold Water, which flows to the bottom layer at the western entrance of Cheju Strait. Temperature and salinity fronts in the northeastern sea area of U Island are formed in the boundary area between the Tsushima Warm Current, which expands towards Cheju Island from the southeastern sea area of Cheju Island and Hows out from the eastern entrance of the strait. Seasonally, additional oceanographic conditions, such as coastal counter-currents, which flow southward, appears within limited areas in the adjacent eastern and western seas of Cheju Island.

• Journal of Soil and Groundwater Environment
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• v.22 no.4
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• pp.9-26
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• 2017

When a warm well located downgradient is captured by cold thermal plume originated from an upgradient cold well, the warm thermal plume is pushed further downgradient in the direction of groundwater flow. If groundwater flow direction is parallel to an aquifer thermal energy storage (ATES), the warm well can no longer be utilized as a heat source during the winter season because of the reduced heat capacity of the warm groundwater. It has been found that when the specific discharge is increased by $1{\times}10^{-7}m/s$ in this situation, the performance of ATES is decreased by approximately 2.9% in the warm thermal plume, and approximately 6.5% in the cold thermal plume. An increase of the specific discharge in a permeable hydrogeothermal system with a relatively large hydraulic gradient creates serious thermal interferences between warm and cold thermal plumes. Therefore, an area comprising a permeable aquifer system with large hydraulic gradient should not be used for ATES site. In case of ATES located perpendicular to groundwater flow, when the specific discharge is increased by $1{\times}10^{-7}m/s$ in the warm thermal plume, the performance of ATES is decreased by about 2.5%. This is 13.8% less reduced performance than the parallel case, indicating that an increase of groundwater flow tends to decrease the thermal interference between cold and warm wells. The system performance of ATES that is perpendicular to groundwater flow is much better than that of parallel ATES.

• Korean Journal of Applied Biomechanics
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• v.31 no.4
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• pp.297-307
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• 2021

Objective: The aim of this study was to analyze kinetic variables between thermotherapy and dynamic warm-up during drop-landing. Method: Twenty male healthy subjects (Age: 21.85 ± 1.90 years, Height: 1.81 ± 0.06 cm, Weight: 68.5 ± 7.06 kg) underwent three treatments applied on the thermotherapy of femoral muscles and a dynamic warm-up. The thermotherapy was performed for 15 minutes while sitting in a chair using an electric heating pad equipped with a temperature control device. Dynamic warm-up performed 14 exercise, a non-treatment was sitting in a chair for 15 minutes. Core temperature measurements of all subjects were performed before landing at a height of 50 cm. During drop-landing, core temperature, joint angle, moment, work of the sagittal plane was collected and analyzed. All analyses were performed with SPSS 21.0 and for repeated measured ANOVA and Post-hoc was Bonferroni. Results: Results indicated that Thermotherapy was increased temperature than other treatments (p = .000). During drop-landing, hip joint of dynamic warm-up was slower for angular velocity (p < .005), and left ankle joint was fastest than other treatments (p = .004). Maximum joint moment of dynamic warm-up was smaller for three joints (hip extension: p = .000; knee flexion/extension: p = .001/.000; ankle plantarflexion: p = .000). Negative work of dynamic warm-up was smaller than other treatments (p = .000). Conclusion: In conclusion, the thermotherapy in the local area doesn't affect the eccentric contraction of the thigh. The dynamic warm-up treatment minimized the joint moment and negative work of the lower joint during an eccentric contraction, it was confirmed that more active movement was performed than other treatment methods.

• The Korean Journal of Ecology
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• v.14 no.4
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• pp.379-398
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• 1991

In order to investigate the ecotypic variations of pulsatilla koreana nakai distributed in korea, 8 local populations of the plant were selected in accordance with latitude and compared on the differences of leaf shape, elongstion, stomatal distribution and dhlorophyll content. The incised angle of the plant is 38。32' in cheju, showing a great difference as compared with 23。77'-30。 32' of the other sites. as to the incised rate, mt. togyu and cheju representsed relatively high values of 49.04% and 48.21% the parted leaved individuals were only observed along the warm current coastal area including cheju, sokcho and sunchon and were 54(62.8%), 2(2.5%) and 3(3.3%) in the sites, respectively. Especially, the individuals consisting of only parted learves were 5(5.8%) in cheju alone and none of the other sites showed such individuals at all. So p. cernua distributed in cheju and p. koreana in inland area can be considered to beecotypic variations of the same species from the upper investigations. According to the elongations of leaf and rachis, the local populations could be classified into 3 types, such as warm current coastal area type(cheju,sunchon and sokcho),southern inland area type(andong, chungju and mt. togyu)and central inland ara type(mt. komdan and hongchon). The dentate numbera of 39.80-43.73 in the warm current area were also different from those of 87% in mt.togyu and 15% in hongchon, while opposite leaflets account for 100% in the other sites. The content of chlorophyll ranged from 0.609 mg/g. d.w.(cheju)to 0.924 mg/g.d.w.(hongchon), showing an increasing trends as the latitudes grow higher. The number of stomata on the low epidermis is much larger than that on the upper epidermis in the whole area. But both aspects showed an increasing tendency, too as the latitude becomes higher.

• Journal of Environmental Science International
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• v.19 no.12
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• pp.1385-1395
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• 2010

Harmful dinoflagellate Cochlodinium polykrikoides blooms have been frequently occurred in coastal areas of the East Sea since 1995. We compared the oceanic conditions in years 1995, 2001 and 2003 when the C. polykrikoides bloom was strong, and in years 1998 and 2004 when the C. polykrikoides bloom was not appeared. We studied temporal and spatial variation of upwelling and geostrophic currents on the western channel of Korean Strait, an entrance of the East Sea. The period and occurrence area of C. polykrikoides bloom was depended on variation of upwelling in summer. In the distributions of geostrophic current, southward current was dominant near the coast in August, 1998 and 2000. Whereas northward current was dominant near and off the coast in August, 1995 and 2003 which the C. polykrikoides bloom was strong. When compared dominant phytoplankton of the coastal areas in each year, Kuroshio indicator species Proboscia alata and Chaetoceros affine were dominant, respectively, in 2001 and 2003 at every stations. However, the dominant species was variable at each coastal area in 1998 and 2000. In 2003, the abundance of Sagitta elegans which is known as the cold water indicator was low, but the abundance of S. enflata, warm water indicator, was very high in Gangneung compared to Sokcho. It seemed that the distribution of S. elegans is restricted by strong warm water current. In conclusion, it was estimated that the distribution of C. polykrikoides bloom in the coastal area of the East Sea was closely related with the strength of East Korea Warm Current and upwelling.