• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.3
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• pp.132-146
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• 2014

The effects of the cold air generated from large cold water mass at the coastal area on observed air temperature in Busan were investigated using AWS(Automatic Weather Station) data at the Busan area operated by Korea Meterological Administration and SST(Sea Surface Temperature) data at the Gijang and Busan area operated by Korean National Fisheries Research Development Institute. First, the temperature difference between the coastal area and the city area was about $1^{\circ}C$ during cold water mass day while it was about $0.5^{\circ}C$ if cold water mass was not appeared. Second, for day time, the temperature at the coastal area was about $1^{\circ}C$ lower than that at the city area during cold water mass day, but the difference was only about $0.4^{\circ}C$ without cold water mass. On the other hand, for night time, the temperature at the coastal area was about $1.2^{\circ}C$ lower than that at the city area during cold water mass day and the difference was about $0.9^{\circ}C$ without cold water mass. As a result, temperature differences at night time were higher than those at day time whether or not cold water mass appeared. The reason for higher temperature at night time might be the urban heat island phenomenon.

• Journal of the Korea Concrete Institute
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• v.25 no.6
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• pp.621-630
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• 2013

Several techniques for steel corrosion detection are proposed and HCP (half cell potential) technique is widely adopted for field investigation. If concrete has cracks on surface, steel corrosion is rapidly accelerated due to additional intrusion of chloride and carbon dioxide ions. This study is for an evaluation of HCP in cracked concrete exposed chloride attack. For this work, RC (reinforced concrete) beams are prepared considering 3 w/c ratios (0.35, 0.55, and 0.70) and several cover depths (10~60 mm) and various crack widths of 0.0~1.0 mm are induced. For 35 days, SST (salt spraying test) is performed for corrosion acceleration, and HCP and corrosion length of rebar are evaluated. With increasing crack width, w/c ratios, and decreasing cover depth, HCP measurements increase. HCP evaluation technique is proposed considering the effects of w/c ratios, crack width, and cover depth. Furthermore anti-corrosive cover depths are obtained through Life365 program and the results are compared with those from this study. The results shows relatively big difference in cracked concrete, however provide similar anti-corrosive conditions in sound concrete.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.1
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• pp.17-25
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• 2020

In this study, three-dimensional fluid flow analyses have been performed in order to investigate the performance characteristics of a horizontal axis tidal turbine (HATT) by solving three-dimensional Reynolds-averaged Navier-Stokes equations utilizing the shear-stress-transport turbulence model. The computational domain for the flow analysis has been composed of hexahedral grids, and the grid dependency test has been carried out so as to determine the optimum grid size. Performance characteristics of the HATT have been investigated in consideration of the effects of hub nose geometry, inflow angle, and the tower. It has been found that the power output can be enhanced along with an increase of the ratio of the length to the diameter of the turbine nose, and the power of HATT has been reduced by approximately 10% when the primary fluid flow had an inflow angle of 15°. The power output of downstream HATT is found to be lower than that of the upstream HATT by about 1%.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.1
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• pp.41-43
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• 2021

Purpose In nuclear medicine blood tests, hemolysis samples are considered as inappropriate sample and are recommended not to be used for blood test. So, the lab are required to collect the blood again in the blood collection room However, The effect of hemolyzed samples on radioimmunoassay has not studied yet. This study was designed to evaluate effects of hemolysis on radioimmunoassay. Materials and Methods The kit manuals of 23 test items were reviewed to confirm whether hemolyzed samples were used. The subjects were 19 general applicants(male : 9, female : 13) and the samples were collected by each two SST tubes, one tube was obtained by centrifugation normally, and the other was obtained hemolyzed sample by centrifugation after external shock. It has been known that highly hemolyzed samples can affect the test results, so the test was performed using the severe hemolyzed sample. The test was performed for each test item using 23 normal serum and hemolysis serum, and SPSS19 program was used for statistical comparison of the test result. Results There was no significant difference between normal serum and hemolysis serum in 21 of 23 test items, but the results of insulin and C-peptide were significantly different(P<0.05). Conclusion It has been known that hemolysis in blood samples can affect the results of biochemical and hematological test, However, hemolysis effect is relatively low. Similarly, this study showed that hemolysis had not much effect on most of immunological radioimmunoassay except for some tests. Therefore, it is thought that the demand for re-collection due to hemolysis will be reduced in the laboratory, which will improve the work process of the laboratory.