• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.197-205
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• 1984

From 1981 to 1982, a series of experiments on the optimum growth temperature, wintering temperature and lethal minimum temperature of the walking catfish Clarias batrachus, of about 12 to 40 g yearlings, were carried out using indoor recirculating aquariums at water temperature between $14^{\circ}C\;and\;34^{\circ}C$. The results are as follows. The optimum temperature of this species was turned out to be approximately $25^{\circ}C$ with highest feed intake and growth rates, and lowest conversion rate than at any other temperatures. The minimum temperature at which the fish can show growth turned out to be $18^{\circ}C$, At this temperature daily growth rate for 62 days was about $0.1\%$ and all fish survived. When this species was kept at $16^{\circ}C$ or lower, no fish survived more than one month and at lower than $14^{\circ}C$ all fish died out in 1 to 7 days. In accordance with these results it could be inferred that $18^{\circ}C$ is the minimum wintering temperature. Rearing this species at the minimum growth temperature for a long time, for wintering for instance, the sudden change of water temperature, especially decreasing to lower than $15^{\circ}C$ can be lethal for all fish.

• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.123-128
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• 2018

MDF was treated on the surface of MDF with fire retardant lacquer, water-soluble flame retardant coat and water-soluble wood cover on the MDF wood, and the pyrolysis characteristics and the atmospheric noxious gas generation characteristics were investigated by using the large capacity thermal analyzer. As a result of investigating pyrolysis and combustion gas generation characteristics after treatment of 0.11 / 11.55 g in terms of mass ratio, it was found that combustion starting time was slightly longer than that of pure MDF in the case of treatment with fire retardant lacquer. The combustion temperature was increased from $340^{\circ}C$ to $450^{\circ}C$. The pyrolysis and combustion gas generation characteristics of the MDF wood treated with the aqueous flame retardant coat showed the changes in combustion starting time and temperature from $260^{\circ}C$ to $542^{\circ}C$ for about 26 minutes at the mass ratio of 0.13 / 11g. Also, when the commercially available waterproof wood cover was treated with 0.13 / 11.55 g of MDF, the sudden weight change tended to increase from $300^{\circ}C$ to $370^{\circ}C$ and showed a second change at approximately $500^{\circ}C$.

• Journal of fish pathology
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• v.24 no.2
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• pp.153-160
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• 2011

The specific antibody response of olive flounder, Paralichthys olivaceus to change in rearing-environmental conditions post immunization with antigen (bovine serum albumin, BSA) and different routes of antigen administration were investigated by enzyme-linked immunosorbent assay (ELISA). To test the effect of routes of antigen administration, flounder were injected intraperioneally or intramuscularlly with 1 mg of BSA. In addition, to test the effect of change in environmental condition post immunization, flounder were injected intraperioneally with 1 mg of antigen, and then were exposed to acute thermal change (the water temperature (WT) was decreased from $21^{\circ}C$ to $15^{\circ}C$ within 30 min and maintained at $15^{\circ}C$ for 3 h), handling (fish were caught and subsequently held out of water for 1 min) or heavy oil (76 g/200 L for 2 days). Consequently, there was no significant difference between intraperioneal (IP) and intramuscular (IM) injections except at 10 days post-immunization. With these results, it suggests that both 1M and IP injections may be used as route of vaccination. Furthermore, no significant difference was observed in the antibody response among the groups exposed to heavy oil, handling, sudden drop of WT and positive control except at 10 days post-immunization. From these results, it was confirmed that specific antibody response was not affected by the above mentioned rearing-environmental conditions, suggesting that vaccination can be employed at changing rearing-environmental conditions.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.4
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• pp.317-324
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• 2015

GNSS was firstly proposed for application in weather forecasting in the mid-1980s. It has continued to demonstrate the practical uses in GNSS meteorology, and other relevant researches are currently being conducted. Precipitable Water Vapor (PWV), calculated based on the GNSS signal delays due to the troposphere of the Earth, represents the amount of the water vapor in the atmosphere, and it is therefore widely used in the analysis of various weather phenomena such as monitoring of weather conditions and climate change detection. In this study we calculated the PWV through the meteorological information from an Automatic Weather Station (AWS) as well as GNSS data processing of a Continuously Operating Reference Station (CORS) in order to analyze the heavy snowfall of the Ulsan area in early 2014. Song’s model was adopted for the weighted mean temperature model (T_m), which is the most important parameter in the calculation of PWV. The study period is a total of 56 days (February 2013 and 2014). The average PWV of February 2014 was determined to be 11.29 mm, which is 11.34% lower than that of the heavy snowfall period. The average PWV of February 2013 was determined to be 10.34 mm, which is 8.41% lower than that of not the heavy snowfall period. In addition, certain meteorological factors obtained from AWS were compared as well, resulting in a very low correlation of 0.29 with the saturated vapor pressure calculated using the empirical formula of Magnus. The behavioral pattern of PWV has a tendency to change depending on the precipitation type, specifically, snow or rain. It was identified that the PWV showed a sudden increase and a subsequent rapid drop about 6.5 hours before precipitation. It can be concluded that the pattern analysis of GNSS PWV is an effective method to analyze the precursor phenomenon of precipitation.