• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.460-464
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• 2012

From 1998 to 2008, the bacteriological quality of seawater in Kamak Bay, Korea, was monitored. The total and fecal coliforms in seawater were monitored as bacterial indicators, and the level of fecal coliform contamination was used to evaluate seawater quality. In the southern shellfish growing area of Kamak Bay, the observed fecal coliform geometric mean (GM) and estimated 90th percentile did not exceed the quality standards for fecal coliforms in seawater in Korea and th USA (GM<14 MPN/100 mL, 90th percentile<43 MPN/100 mL). The GM and estimated 90th percentile of the fecal coliform levels in the adjacent northern area of Kamak Bay were higher than in the southern area. Stations near wastewater discharge sites and urban areas in the north had the lowest quality and did not meet the bacteriological seawater quality criteria. The high fecal coliform levels in the Seonso coastal region near wastewater discharges and northern urban areas declined significantly following dredging and operation of a sewage treatment plant.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.614-622
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• 2010

The sanitary quality of a shellfish-growing area in Gangjinman, Korea, was assessed through a bacteriological examination of seawater form January 2007 to December 2009. The range of the geometric mean (GM) and the estimated 90th percentile for most-probable-number (MPN) values for fecal coliforms in samples collected in the designated area were 2.0-2.4 and 6.1-11.5 MPN/100 mL, respectively. Therefore, the bacteriological quality of seawater in the designated area in the Gangjinman area met the National Shellfish Sanitation Program (NSSP, USA) guidelines for approved areas. Also, the sanitary status of shellfish harvested from the designated area met the Korean Shellfish Sanitation Program (KSSP) fecal coliform criterion (<230 MPN/100 g). However, the degree of bacteriological contamination increased rapidly, and water quality exceeded the criteria for approved areas when large amounts of rain fell before the sampling date. Fortunately, fecal pollutants did not affect the bacteriological quality of a buffer zone established between the shoreline and the designated area. These results indicate that the current buffer zone established around the designated area protects the designated area properly.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.611-615
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• 2007

The purpose of this study was to evaluate the immunogenicity and safety of Salmonella Typhi Vi capsular polysaccharide vaccine (Vi vaccine) in Korea. The immunogenicity of a single dose of Vi vaccine was evaluated in 157 subjects (75 children and 82 adults) before and at 1, 6, and 12 months after vaccination. Immunogenicity was measured with a passive hemagglutination assay (PHA), quantified as geometric mean titers (GMTs) and seroconversion rates. The safety of the vaccine was investigated by determining adverse reactions occurring within 4h, 3 days, and 1 month after injection. The seroconversion rate for children and adults 1 month after vaccination was 96.92% and 89.02%, respectively. In the case of children, the GMTs of Vi antibodies before vaccination were $5.87{\pm}1.34\;and\;142.59{\pm}2.39$ at one month after vaccination. For adults, the GMTs before and one month after vaccination were $5.58{\pm}1.28\;and\;58.56{\pm}3.67$, respectively. Vi antibodies persisted for as long as 6 and 12 months after vaccination. All adverse reactions in adults and children were minor and did not require treatment. The Vi CPS vaccine was safe and immunogenic in adults and children older than 5 years.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.605-616
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• 2019

This study evaluated the abundance and antimicrobial resistance of Escherichia coli in oysters Crassostrea gigas and major inland pollution sources sampled in 2014-2015 from Jaranman-Saryangdo on the southern coast of Korea. The ranges of the geometric mean of E. coli concentrations in oysters and major inland pollution sources were <20-29.8 MPN/100 g and 7.5-137.2 MPN/100 g, respectively. We isolated 247 strains of E. coli (28 from oysters and 247 from major inland pollution sources) and examined the antimicrobial resistance patterns of all isolates. Isolates from both sources were highly resistant to rifampin (99.5-100%) and cephalothin (70.8-78.6%). The resistance rate was higher in E. coli isolated from oysters those from inland pollution sources. Multiple resistance against at least four antimicrobials was observed in 85.7% and 21.0% of the oyster and major inland pollution sources isolates, respectively.

• Journal of the Korean Society of Tobacco Science
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• v.28 no.1
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• pp.58-66
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• 2006

Threshold limit value (TLV) test between expert and consumer panel was conducted about absolute, recognition and difference threshold respectively. And we tried to suggest appropriate and minimum acceptable menthol concentration level by consumer panel. Determination of threshold value was based on ASTM E 679-79 method by forced-choice ascending concentration series. In addition, a semi-ascending paired difference method was referred to conduct test. The group threshold value was determined as the value of geometric mean individual threshold. The smokers were dividend by two groups, trained and consumer panel. Trained panel was selected according to sensitivity to menthol discrimination. Consumer panel wasrecruited in proportion as population ratios including female smokers. They were all over twenty years old volunteers and summed up thirty four persons. In terms of sensor evaluation, overall difference test with seven-category scale by both trained and consumer panelists were done. On judging correct or incorrect answer, two by three cut-off levels applied to. Every test was conducted with two sessions, before smoking and during smoking period. And, only two samples served each paneI per test with regard to sensory fatigue and reliable results. All tests were replicated, and in total 32 times per panelist. In conclusion, the recognition threshold about consumer and expert panel was 358 ppm/cig. and 276 ppm/cig. in separately. Besides, absolute and difference thresholds were obtained also. And, we conduct difference threshold test with two different ways, upward and downward. And, The results of each method were 246, 195 ppm/cig., 1414, 1336 ppm/cig. and 1047, 972 ppm/cig.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.4
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• pp.265-275
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• 2012

Objectives: The aim of this study was to investigate the distribution patterns and exposure concentrations of biological hazards in waste handling industries. Methods: We selected 3 recyclable waste sorting plants(RWS), 2 food recycling plants(FR), 1 landfill area(LA) and 1 waste incineration plant(WI). Total airborne bacteria and fungi were measured with single stage impactor and gelatin filters. Endotoxin and glucan were measured with polycarbonate filters in total and respirable dust. Results: The geometric mean of airborne bacterial concentration was the highest in FR($3,273CFU/m^3$), followed by LA, RWS, and WI as 1,334, 934, and $860CFU/m^3$. The fungal concentrations were 6,031, 5,052, 3,307, and $713CFU/m^3$ in RWS, WI, FR, and LA, respectively. By process, WI pit showed the highest concentrations of bacteria, fungi, and endotoxin, followed by inside of bulldozer in LA. The indoor to outdoor ratios of bacteria, fungi, endotoxin and glucan were 2.3, 4.0, 2.3, and 5.0 in RWS, 29.5, 4.9, 7.6, and 5.0 in FR, 5.3, 8.7, 26.8, and 9.5 in WI, respectively. Conclusions: We found that biological hazards, specifically bacteria in FR, fungi in RWS and endotoxin in WI pit and bulldozer at LA, should be controlled to prevent worker's respiratory diseases.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.4
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• pp.284-292
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• 2012

Objectives: The objective of this study was to investigate the relations between the bacterial concentration and the environmental factors in the water soluble metal working fluids at factories. Methods: The bacterial concentrations for airborne and fluid samples of 7 factories were quantified during the summer season. And we statistically analysed the relations between the bacterial concentrations and the factors such as temperature, relative humidity, usage quantity, mixing ratio and exchange interval. Results: The geometric mean levels of the airborne bacterial concentrations were 79.1(range : N.D.~686) $CFU/m^{3}$ and 68.1(range: N.D.~919) $CFU/m^{3}$ in the process and outdoor. The airborne bacterial concentrations showed no statistical difference by process, usage quantity, mixing ratio and exchange interval. The airborne bacterial concentrations had negatively weak correlations with air temperature and relative air humidity(p<0.05). The bacterial concentrations and pH showed significantly negative correlations in the fluids(p<0.05). And the airborne bacterial concentrations in factories and those in metal working fluids showed no statistical relationship. Conclusions: In the water soluble metal working fluids using factories, the airborne bacterial concentrations of the process were related to those of the outdoor and environmental factors, rather than the onsite contaminated metal working fluids.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.4
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• pp.391-402
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• 2016

Among the various remote sensing sensors compared to the electro-optical sensors, SAR (Synthetic Aperture Radar) is very suitable for assessing damaged areas induced by disaster events owing to its all-weather day and night acquisition capability and sensitivity to geometric variables. The conventional CD (Change Detection) method that uses two-date data is typically used for mapping damage over extensive areas in a short time, but because data from only two dates are used, the information used in the conventional CD is limited. In this paper, we propose a novel CD method that is extended to use data consisting of two pre-disaster SAR data and one post-disaster SAR data. The proposed CD method detects changes by using a similarity weight image derived from the neighborhood information of a pixel in the data from the three dates. We conducted an experiment using three single polarization ALOS PALSAR (Advanced Land Observing Satellite/Phased Array Type L-Band) data collected over Miyagi, Japan which was seriously damaged by the 2011 east Japan tsunami. The results demonstrated that the mapping accuracy for damaged areas can be improved by about 26% with an increase of the g-mean compared to the conventional CD method. These improved results prove the performance of our proposed CD method and show that the proposed CD method is more suitable than the conventional CD method for detecting damaged areas induced by disaster.

• International Journal of Highway Engineering
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• v.17 no.5
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• pp.47-56
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• 2015

PURPOSES: The purpose of this study is to estimate the impact of variable message signage (VMS) on traffic safety as a function of road curve radius using statistical methods. METHODS: In order to analyze the impact of VMS installations on traffic safety, travel speed, lateral distance, and geometric data relating to road curvature in each study area was acquired and analyzed for the impact of providing VMS information on driver performance and traffic safety using statistical methods including student t-test, Mann-Whitney test, and the Anderson-Darling test for estimating traffic safety hazard zone in each lane. RESULTS: As a result of analyzing driver performance characteristics before and after providing VMS information, it was determined that by providing VMS information, mean travel speed is deceased and vehicles are driven with increased precision, following the centerline in the first and second lanes. Also the results of analyzing traffic safety impacts of VMS indicate that traffic safety performance factors in the first lane of the Gapyeong section can, on average, increase in the left and right side of the lane by 19.22% and 68.98%, respectively, and in the case of the second lane, safety impacts, on average, can increase in both sides by 100%. For the Hongcheon section, traffic safety impacts in the first lane, on average, can increase along the left and right sides of the lane by 32.31% and 47.18%, and within the second lane, traffic safety can be increased along the left and right side of the lane by 10.97% and -0.01%, respectively. CONCLUSIONS: Based on the results of this study, the impact on traffic safety obtained by providing VMS information for road sections with smaller curve radii is greater than can be obtained for road sections with larger curve radii.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.653-660
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• 2004

To increase the efficiency of the urban areas, pipe section steel piers, which have relatively small sections, must be constructed. Since smaller sections mean decreased load capacity, longitudinal stiffeners were applied to the pipe section steel piers to increase their load capacity. Increased load capacity through longitudinal stiffeners, however, could not yet be confirmed. Therefore, the effect of longitudinal stiffeners on the load capacity of pipe section steel piers still needs to be studied. In this paper, the effect of the number of longitudinal stiffeners on the load capacity of steel piers was determined by carrying out elastic plastic FE analysis on material and geometric non-linearity. In addition, comparative analyses of the parameters of the width, the thickness of longitudinal stiffeners, and the slenderness ratio of steel piers were carried out to determine the effects of longitudinal stiffeners.