• Journal of the Korean Institute of Navigation
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• v.21 no.4
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• pp.39-47
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• 1997

We researched the mechanism on th flucturain of Bottom Cold Water in the western channel of Korea Strait, using 13 years(1981~1933) oceanographic data of FRDA. The bottom cold water in the western channel appears more often in summer and fall than in winter and spring, and its year-to-year variation of temperature is very large. Such variation seems to be closely related with the variations of cold waters in the subsurface layer of the southwestern East Sea. According to the longitudinal temperature distribution along the korean southeastern coast, a density difference occurs all the time at the still deepth between the western channel and the southwestern East Sea. Thus, it is inferred that the cold waters would intrude into the western channle form the subsurface layer in the southwestern East Sea as a density-driven current, and it intensity depends upon the density difference.

• Journal of the Korean housing association
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• v.19 no.1
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• pp.79-88
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• 2008

Hot water is used by having a wash, dishes, taking tub and drinking water in residential buildings, and the use objective is to raise comfort of human body sense, washing and sterilization effect and so on. Cold & hot water supply system is understanded simpler than HVAC systems relatively, so it is true that pace of performance improvement is slower than other systems for plan and technical development. In this study, the performance evaluations are conducted under the condition of composition ratio by 1:1 for cold & hot water supply manifold system using functionally complex valves such as constant flow regulating valve and 3-way mixing valve in the area of $105.6m^2$ apartment which consist of the largest part of the whole apartment. Also, flow rate related to simultaneous use of faucets and change of hot water temperature are compared with the existing method.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.57-66
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• 1967

Cold $(0^{\circ}C)$ or warm $(25^{\circ}C)$ fresh and sea water were flooded into the lungs of rabbits through tracheal canule. Respiratory arrest ensued in 19.5 minutes in the warm fresh water flooded rabbits and was the longest survival time among the experimental groups. The survival times in the other groups were: 2.32 minutes in cold fresh water group, 2.75 minutes in .warm sea water group, and 4.57 minutes in cold sea water group. Cardiac output was measured by means of T-1824 dilution technique after 2 or 3 minutes of flooding in 27 rabbits. Blood pressure was observed by mercury manometer throughout the survival time in 40 rabbits. The following results were obtained. 1. Cardiac output in the warm fresh water flooded and sea water flooded animal was smaller than that of control rabbits. In the cold fresh water flooded animal cardiac output was greater than that of the control animal. 2. Time constants of T-1824 dilution curve of experimental group were elongated than the normal curve. 3. Central blood volume showed an increase in the fresh water group, a decrease in cold sea water group and no change in warm sea water group. 4. In all of the experimental groups arterial blood Pressure showed an abrupt and great variations after flooding of lungs and lasted about 30 seconds. Thereafter, arterial pressure remained at a plateau level until the sudden fall to zero and this was almost coincided with the time of respiratory arrest. The Plateau level of arterial Pressure in fresh water group was about 10 mmHg higher than the control value, and it was lower than the control value in warm sea water group. In cold sea water group the plateau was made up by fluctuations around the control value. 5. Osmosis of water through the lung alveolar membrane occured in all animals. Fresh water caused hemodilution and sea water caused hemoconcentration. 6. In sea water flooded animal more volume of water was recovered through the tracheal canule than the volume injected into trachea. This was interpreted as the consequence of the shift of water from plasma to alveolar sac. 7. Relative freight of lung was greater in fresh water group than sea water group. In all animal lung edema ensued. 8. The mechanisms of cardiac output variations were discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.359-371
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• 1998

The cold water event near Gampo-Ulgi coast in summers between 1987 and 1994 are studied using sea surface temperature records at the coastal stations, ocean winds measured by SSM/I and AVHRR SST images. The response time of the cold water events by upwelling is less than two days and surface cold water expands up to the Ulleung Island. An analysis of 61 upwelling favorable winds indicates that the surface water temperature drops more than $1^{\circ}C\;in\;80\%$ of the south-westerly wind events. The linear correlation coefficient between wind impulses and the maximum temperature drops is good (0.6). It is found that the major cause of the cold water events is the along-shore wind in summer. The bottom topography and off-shore direction of the East Korean Warm Current by the potential vorticity conservation near Gampo coast also contribute the formation of the cold water along the southeast coast of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.776-782
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• 2015

We examined the community structure of fish off the coast of Jindo Island in response to a cold water appearance in the southwestern sea of Korea each August between 2013–2015. Using a gape net with wings, we collected 31 taxa during the study period, wherein the most dominant species was Engraulis japonicus. Collichthys lucidus and Neosalanx andersoni, which are mainly distributed in the western sea of Korea, increased in abundance and were dominant in August 2013, possibly due to the apparent intrusion of cold water (< 19°C) from offshore into the coastal waters of Jindo Island. Meanwhile, Scomberomorus niphonius and Sardinella zunasi, which are known as warmwater migratory species, increased in abundance and were dominant in August 2015, likely influenced by the warmer water (> 20°C) at the coast, which resulted in a noticeable lessening of the cold water in the study area. However, no significant differences were observed in fish community structure in the month of August between 2013–1015. This implies that the small-scale spatial and temporal variations in the cold water had limited effects on the fish community structure, even though the abundances of several dominant species varied in the coastal waters.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.559-572
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• 2019

In the southeast sea of Korea, the cold water is concentrated in every summer, showing in abnormal oceanic conditions. Cold water occurred in the southeast sea is dominantly influenced by wind, which occurs when the south wind is continuously blowing for 3 to 7 days more. In this study, water temperature, wind speed and direction data of KMA, KHOA and KHNP, Chlorophyll-a of COMS/GOCI, GHRSST Level 4 SST of NASA, and red tide alert data of the National Institute of Fisheries Science were used to analyze the correlation between occurrence and change of the cold water and the red tide of Cochlodinium polykrikoides. The upwelling cold water mass showed a characteristic of moving northward along the current and occurrence a high concentration of chlorophyll along the water mass. Also, when the warm current were strong, the characteristic of red tide showed a northward moving.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.3
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• pp.243-251
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• 2007

This experiment was conducted to investigate the effect of particles on the heat transfer characteristics of fluids flowing in a cold water tube. Plastic beads with 3 different sizes were used as flowing particles with cold water. An experimental test section was composed of concentric double tubes having diameters of 25mm for the inner tube and 50mm for the outer tube. The materials for the inner and outer tubes are copper and PVC respectively. It was found that the particles enhanced the heat transfer coefficient by random and vortex motion in the fluid. Hence the heat transfer coefficients for the fluid with 2mm, 5mm and $2{\times}6mm$ particles were $7%{\sim}37%$ higher than the fluid without the particles.

• Ocean Science Journal
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• v.41 no.4
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• pp.291-299
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• 2006

Hydrographic surveys were carried out four times in the western channel of the Korea Strait in March and August 2003 and in June and November 2004. The bottom cold water, which was lower than $10^{\circ}C$, appeared in the channel trough except in March 2003. It flowed southwestward along the shelf of Korean coasts in August 2003 and in November 2004. The width and the maximum speed of the intrusion current were about 20 km and approximately $25\;cm\;s^{-1}$, respectively, off Ulsan, Korea. The volume transport of the bottom cold water was estimated 0.019 Sv ($Sv{\equiv}10^6\;m^3\;s^{-1}$) in August 2003 and 0.026 Sv in November 2004.

• 한국해양학회지
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• v.23 no.1
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• pp.13-23
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• 1988

A simple model is presented which may explain the distributions of cold surface water near Ulsan. The model considers the problem as an advection-diffusion process with cold source confined within narrow coastal areas. The natural warming due to vertical process (interaction either with the atmosphere above or with the subsurface water below) also plays an important role. A simple numerical computation reproduces the observations quite well. The localization of cold surface water occurs at the point where the local warm current separates from the coast.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2505-2510
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• 2008

A nuclear fuel test loop (after below, FTL) is installed in IR1 of an irradiation hole in HANARO for testing neutron irradiation characteristics and thermo hydraulic characteristics of a fuel loaded in a light water power reactor or a heavy water power reactor. When HANARO is normally operated, the fuel loaded in the irradiation hole has a nuclear reaction heat generated by a neutron irradiation. To remove the generated heat and to maintain an operation condition of the test fuel, a main cooling water system (MCWS) is installed in the OPS of the FTL. This paper describes the cold function test results of the MCWS. It was confirmed through the test results that the system met the design requirements under a cold operation condition.